Radiologists’ Interpretive Skills in Screening vs. Diagnostic Mammography: Are They Related?

PubMed Central

Elmore, Joann G.; Cook, Andrea J.; Bogart, Andy; Carney, Patricia A.; Geller, Berta; Taplin, Stephen; Buist, Diana SM; Onega, Tracy; Lee, Christoph I.; Miglioretti, Diana L.

2016-01-01

Purpose To determine whether radiologists who perform well in screening also perform well in interpreting diagnostic mammography. Materials & Methods We evaluated the accuracy of 468 radiologists interpreting 2,234,947 screening and 196,164 diagnostic mammograms. Adjusting for site, radiologist, and patient characteristics, we identified radiologists with performance in the highest tertile and compared to those with lower performance. Results A moderate correlation was noted for radiologists’ accuracy when interpreting screening versus their accuracy on diagnostic exams: sensitivity (rspearman=0.51, 95% CI: 0.22, 0.80; P=0.0006), specificity (rspearman=0.40, 95% CI: 0.30, 0.49; P<0.0001). Conclusion Different educational approaches to screening and diagnostic imaging should be considered. PMID:27438069

An ARM data-oriented diagnostics package to evaluate the climate model simulation

NASA Astrophysics Data System (ADS)

Zhang, C.; Xie, S.

2016-12-01

A set of diagnostics that utilize long-term high frequency measurements from the DOE Atmospheric Radiation Measurement (ARM) program is developed for evaluating the regional simulation of clouds, radiation and precipitation in climate models. The diagnostics results are computed and visualized automatically in a python-based package that aims to serve as an easy entry point for evaluating climate simulations using the ARM data, as well as the CMIP5 multi-model simulations. Basic performance metrics are computed to measure the accuracy of mean state and variability of simulated regional climate. The evaluated physical quantities include vertical profiles of clouds, temperature, relative humidity, cloud liquid water path, total column water vapor, precipitation, sensible and latent heat fluxes, radiative fluxes, aerosol and cloud microphysical properties. Process-oriented diagnostics focusing on individual cloud and precipitation-related phenomena are developed for the evaluation and development of specific model physical parameterizations. Application of the ARM diagnostics package will be presented in the AGU session. This work is performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, IM release number is: LLNL-ABS-698645.

Effects of disease severity distribution on the performance of quantitative diagnostic methods and proposal of a novel 'V-plot' methodology to display accuracy values.

PubMed

Petraco, Ricardo; Dehbi, Hakim-Moulay; Howard, James P; Shun-Shin, Matthew J; Sen, Sayan; Nijjer, Sukhjinder S; Mayet, Jamil; Davies, Justin E; Francis, Darrel P

2018-01-01

Diagnostic accuracy is widely accepted by researchers and clinicians as an optimal expression of a test's performance. The aim of this study was to evaluate the effects of disease severity distribution on values of diagnostic accuracy as well as propose a sample-independent methodology to calculate and display accuracy of diagnostic tests. We evaluated the diagnostic relationship between two hypothetical methods to measure serum cholesterol (Chol rapid and Chol gold ) by generating samples with statistical software and (1) keeping the numerical relationship between methods unchanged and (2) changing the distribution of cholesterol values. Metrics of categorical agreement were calculated (accuracy, sensitivity and specificity). Finally, a novel methodology to display and calculate accuracy values was presented (the V-plot of accuracies). No single value of diagnostic accuracy can be used to describe the relationship between tests, as accuracy is a metric heavily affected by the underlying sample distribution. Our novel proposed methodology, the V-plot of accuracies, can be used as a sample-independent measure of a test performance against a reference gold standard.

Validation of Ten Noninvasive Diagnostic Models for Prediction of Liver Fibrosis in Patients with Chronic Hepatitis B

PubMed Central

Cheng, Jieyao; Hou, Jinlin; Ding, Huiguo; Chen, Guofeng; Xie, Qing; Wang, Yuming; Zeng, Minde; Ou, Xiaojuan; Ma, Hong; Jia, Jidong

2015-01-01

Background and Aims Noninvasive models have been developed for fibrosis assessment in patients with chronic hepatitis B. However, the sensitivity, specificity and diagnostic accuracy in evaluating liver fibrosis of these methods have not been validated and compared in the same group of patients. The aim of this study was to verify the diagnostic performance and reproducibility of ten reported noninvasive models in a large cohort of Asian CHB patients. Methods The diagnostic performance of ten noninvasive models (HALF index, FibroScan, S index, Zeng model, Youyi model, Hui model, APAG, APRI, FIB-4 and FibroTest) was assessed against the liver histology by ROC curve analysis in CHB patients. The reproducibility of the ten models were evaluated by recalculating the diagnostic values at the given cut-off values defined by the original studies. Results Six models (HALF index, FibroScan, Zeng model, Youyi model, S index and FibroTest) had AUROCs higher than 0.70 in predicting any fibrosis stage and 2 of them had best diagnostic performance with AUROCs to predict F≥2, F≥3 and F4 being 0.83, 0.89 and 0.89 for HALF index, 0.82, 0.87 and 0.87 for FibroScan, respectively. Four models (HALF index, FibroScan, Zeng model and Youyi model) showed good diagnostic values at given cut-offs. Conclusions HALF index, FibroScan, Zeng model, Youyi model, S index and FibroTest show a good diagnostic performance and all of them, except S index and FibroTest, have good reproducibility for evaluating liver fibrosis in CHB patients. Registration Number ChiCTR-DCS-07000039. PMID:26709706

[Evaluation of diagnostic criteria of syphilitic infection by means of gas chromatography and mass-spectrometry].

PubMed

Vorob'ev, A A; Mironov, A Iu; Istratov, V G; Osman, K A

2005-01-01

In order to estimate possibility of chromatographic criteria application in diagnostics of syphilitic infection, the authors researched in three directions: evaluation of dysmetabolism of carbohydrate, lipid and amino acid components in patients' serum; search of signal compounds that serve as microbe "cooperative sensitivity" activators (lactones, quinolones, furan boron ethers) with evaluation of the risk of luetic infection generalization; indication of organ lesion markers (the brain, liver, bone structures). The factor analysis performed by the researchers allowed to determine priorities of clinical, laboratory and chromatographic data according to their value. The diagnostic value of various diagnostic chromatographic criteria was estimated as follows: the diagnostic sensitivity was 79.6% to 97.2%, the diagnostic specificity was 50.0% to 92.7%, the positive diagnostic predictability was 61.8% to 94.7% and the negative diagnostic predictability was 60.9% to 95.1%.

Multiple performance measures are needed to evaluate triage systems in the emergency department.

PubMed

Zachariasse, Joany M; Nieboer, Daan; Oostenbrink, Rianne; Moll, Henriëtte A; Steyerberg, Ewout W

2018-02-01

Emergency department triage systems can be considered prediction rules with an ordinal outcome, where different directions of misclassification have different clinical consequences. We evaluated strategies to compare the performance of triage systems and aimed to propose a set of performance measures that should be used in future studies. We identified performance measures based on literature review and expert knowledge. Their properties are illustrated in a case study evaluating two triage modifications in a cohort of 14,485 pediatric emergency department visits. Strengths and weaknesses of the performance measures were systematically appraised. Commonly reported performance measures are measures of statistical association (34/60 studies) and diagnostic accuracy (17/60 studies). The case study illustrates that none of the performance measures fulfills all criteria for triage evaluation. Decision curves are the performance measures with the most attractive features but require dichotomization. In addition, paired diagnostic accuracy measures can be recommended for dichotomized analysis, and the triage-weighted kappa and Nagelkerke's R 2 for ordinal analyses. Other performance measures provide limited additional information. When comparing modifications of triage systems, decision curves and diagnostic accuracy measures should be used in a dichotomized analysis, and the triage-weighted kappa and Nagelkerke's R 2 in an ordinal approach. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluating the Performance Diagnostic Checklist-Human Services to Assess Incorrect Error-Correction Procedures by Preschool Paraprofessionals

ERIC Educational Resources Information Center

Bowe, Melissa; Sellers, Tyra P.

2018-01-01

The Performance Diagnostic Checklist-Human Services (PDC-HS) has been used to assess variables contributing to undesirable staff performance. In this study, three preschool teachers completed the PDC-HS to identify the factors contributing to four paraprofessionals' inaccurate implementation of error-correction procedures during discrete trial…

Statistical Classification for Cognitive Diagnostic Assessment: An Artificial Neural Network Approach

ERIC Educational Resources Information Center

Cui, Ying; Gierl, Mark; Guo, Qi

2016-01-01

The purpose of the current investigation was to describe how the artificial neural networks (ANNs) can be used to interpret student performance on cognitive diagnostic assessments (CDAs) and evaluate the performances of ANNs using simulation results. CDAs are designed to measure student performance on problem-solving tasks and provide useful…

An Evaluation of the Performance Diagnostic Checklist-Human Services to Assess an Employee Performance Problem in a Center-Based Autism Treatment Facility

ERIC Educational Resources Information Center

Ditzian, Kyle; Wilder, David A.; King, Allison; Tanz, Jeanine

2015-01-01

The Performance Diagnostic Checklist-Human Services (PDC-HS) is an informant-based tool designed to assess the environmental variables that contribute to poor employee performance in human services settings. We administered the PDC-HS to 3 supervisors to assess the variables that contributed to poor performance by 4 staff members when securing…

Performance of optically stimulated luminescence Al₂O₃ dosimeter for low doses of diagnostic energy X-rays.

PubMed

Lim, Chang Seon; Lee, Sang Bock; Jin, Gye Hwan

2011-10-01

Personal dosimeters measure the radiation dose from exposure to hazardous sources outside the body. The present manuscript evaluates the performance of a commercially available optically stimulated luminescence (OSL) Al₂O₃ dosimeter using diagnostic energy X-rays. The OSL system satisfies the ANSI N13.11-2001 performance criteria for low dose diagnostic energy X-rays. Non-uniformity of sensitivity, dose linearity, X-ray energy response, and angular performance are all within the criteria of IEC-62387-1(2007). Copyright © 2011 Elsevier Ltd. All rights reserved.

Using the arthroscopic surgery skill evaluation tool as a pass-fail examination.

PubMed

Koehler, Ryan J; Nicandri, Gregg T

2013-12-04

Examination of arthroscopic skill requires evaluation tools that are valid and reliable with clear criteria for passing. The Arthroscopic Surgery Skill Evaluation Tool was developed as a video-based assessment of technical skill with criteria for passing established by a panel of experts. The purpose of this study was to test the validity and reliability of the Arthroscopic Surgery Skill Evaluation Tool as a pass-fail examination of arthroscopic skill. Twenty-eight residents and two sports medicine faculty members were recorded performing diagnostic knee arthroscopy on a left and right cadaveric specimen in our arthroscopic skills laboratory. Procedure videos were evaluated with use of the Arthroscopic Surgery Skill Evaluation Tool by two raters blind to subject identity. Subjects were considered to pass the Arthroscopic Surgery Skill Evaluation Tool when they attained scores of ≥ 3 on all eight assessment domains. The raters agreed on a pass-fail rating for fifty-five of sixty videos rated with an interclass correlation coefficient value of 0.83. Ten of thirty participants were assigned passing scores by both raters for both diagnostic arthroscopies performed in the laboratory. Receiver operating characteristic analysis demonstrated that logging more than eighty arthroscopic cases or performing more than thirty-five arthroscopic knee cases was predictive of attaining a passing Arthroscopic Surgery Skill Evaluation Tool score on both procedures performed in the laboratory. The Arthroscopic Surgery Skill Evaluation Tool is valid and reliable as a pass-fail examination of diagnostic arthroscopy of the knee in the simulation laboratory. This study demonstrates that the Arthroscopic Surgery Skill Evaluation Tool may be a useful tool for pass-fail examination of diagnostic arthroscopy of the knee in the simulation laboratory. Further study is necessary to determine whether the Arthroscopic Surgery Skill Evaluation Tool can be used for the assessment of multiple arthroscopic procedures and whether it can be used to evaluate arthroscopic procedures performed in the operating room.

Systematic Review of Health Economic Evaluations of Diagnostic Tests in Brazil: How accurate are the results?

PubMed

Oliveira, Maria Regina Fernandes; Leandro, Roseli; Decimoni, Tassia Cristina; Rozman, Luciana Martins; Novaes, Hillegonda Maria Dutilh; De Soárez, Patrícia Coelho

2017-08-01

The aim of this study is to identify and characterize the health economic evaluations (HEEs) of diagnostic tests conducted in Brazil, in terms of their adherence to international guidelines for reporting economic studies and specific questions in test accuracy reports. We systematically searched multiple databases, selecting partial and full HEEs of diagnostic tests, published between 1980 and 2013. Two independent reviewers screened articles for relevance and extracted the data. We performed a qualitative narrative synthesis. Forty-three articles were reviewed. The most frequently studied diagnostic tests were laboratory tests (37.2%) and imaging tests (32.6%). Most were non-invasive tests (51.2%) and were performed in the adult population (48.8%). The intended purposes of the technologies evaluated were mostly diagnostic (69.8%), but diagnosis and treatment and screening, diagnosis, and treatment accounted for 25.6% and 4.7%, respectively. Of the reviewed studies, 12.5% described the methods used to estimate the quantities of resources, 33.3% reported the discount rate applied, and 29.2% listed the type of sensitivity analysis performed. Among the 12 cost-effectiveness analyses, only two studies (17%) referred to the application of formal methods to check the quality of the accuracy studies that provided support for the economic model. The existing Brazilian literature on the HEEs of diagnostic tests exhibited reasonably good performance. However, the following points still require improvement: 1) the methods used to estimate resource quantities and unit costs, 2) the discount rate, 3) descriptions of sensitivity analysis methods, 4) reporting of conflicts of interest, 5) evaluations of the quality of the accuracy studies considered in the cost-effectiveness models, and 6) the incorporation of accuracy measures into sensitivity analyses.

Evaluation of lymph node status after neoadjuvant chemotherapy in breast cancer patients: comparison of diagnostic performance of ultrasound, MRI and ¹⁸F-FDG PET/CT.

PubMed

You, S; Kang, D K; Jung, Y S; An, Y-S; Jeon, G S; Kim, T H

2015-08-01

To evaluate the diagnostic performance of ultrasound, MRI and fluorine-18 fludeoxyglucose positron emission tomography (¹⁸F-FDG PET)/CT for the diagnosis of metastatic axillary lymph node (ALN) after neoadjuvant chemotherapy (NAC) and to find out histopathological factors affecting the diagnostic performance of these imaging modalities. From January 2012 to November 2014, 191 consecutive patients with breast cancer who underwent NAC before surgery were retrospectively reviewed. We included 139 patients with ALN metastasis that was confirmed on fine needle aspiration or core needle biopsy at initial diagnosis. After NAC, 39 (28%) patients showed negative conversion of ALN on surgical specimens of sentinel lymph node (LN) or ALN. The sensitivity of ultrasound, MRI and PET/CT was 50% (48/96), 72% (70/97) and 22% (16/73), respectively. The specificity of ultrasound, MRI and PET/CT was 77% (30/39), 54% (21/39) and 85% (22/26), respectively. The Az value of combination of ultrasound and PET/CT was the highest (0.634) followed by ultrasound (0.626) and combination of ultrasound, MRI and PET/CT (0.617). The size of tumour deposit in LN and oestrogen receptor was significantly associated with the diagnostic performance of ultrasound (p < 0.001 and p = 0.009, respectively) and MRI (p = 0.045 and p = 0.036, respectively). The percentage diameter decrease, size of tumour deposit in LN, progesterone receptor, HER2 and histological grade were significantly associated with the diagnostic performance of PET/CT (p = 0.023, p = 0.002, p = 0.036, p = 0.044 and p = 0.008, respectively). On multivariate logistic regression analysis, size of tumour deposit within LN was identified as being independently associated with diagnostic performance of ultrasound [odds ratio, 13.07; 95% confidence interval (CI), 2.95-57.96] and PET/CT (odds ratio, 6.47; 95% CI, 1.407-29.737). Combination of three imaging modalities showed the highest sensitivity, and PET/CT showed the highest specificity for the evaluation of ALN metastasis after NAC. Ultrasound alone or combination of ultrasound and PET/CT showed the highest positive-predictive value. The size of tumour deposit within ALN was significantly associated with diagnostic performance of ultrasound and PET/CT. This study is about the diagnostic performance of ultrasound, MRI, PET/CT and combination of each imaging modality for the evaluation of metastatic ALN after NAC. Of many histopathological factors, only the size of tumour deposit within ALN was an independent factor associated with the diagnostic performance of ultrasound and PET/CT.

CLINICAL APPROACH TO THE DIAGNOSTIC EVALUATION OF HERDITARY AND ACQUIRED NEUROMUSCULAR DISEASES

PubMed Central

McDonald, Craig M.

2012-01-01

SYNOPSIS In the context of a neuromuscular disease diagnostic evaluation, the clinician still must be able to obtain a relevant patient and family history and perform focused general, musculoskeletal, neurologic and functional physical examinations to direct further diagnostic evaluations. Laboratory studies for hereditary neuromuscular diseases include relevant molecular genetic studies. The EMG and nerve conduction studies remain an extension of the physical examination and help to guide further diagnostic studies such as molecular genetic studies, and muscle and nerve biopsies. All diagnostic information needs to be interpreted not in isolation, but within the context of relevant historical information, family history, physical examination findings, and laboratory data, electrophysiologic findings, pathologic findings, and molecular genetic findings if obtained. PMID:22938875

DECIDE: a software for computer-assisted evaluation of diagnostic test performance.

PubMed

Chiecchio, A; Bo, A; Manzone, P; Giglioli, F

1993-05-01

The evaluation of the performance of clinical tests is a complex problem involving different steps and many statistical tools, not always structured in an organic and rational system. This paper presents a software which provides an organic system of statistical tools helping evaluation of clinical test performance. The program allows (a) the building and the organization of a working database, (b) the selection of the minimal set of tests with the maximum information content, (c) the search of the model best fitting the distribution of the test values, (d) the selection of optimal diagnostic cut-off value of the test for every positive/negative situation, (e) the evaluation of performance of the combinations of correlated and uncorrelated tests. The uncertainty associated with all the variables involved is evaluated. The program works in a MS-DOS environment with EGA or higher performing graphic card.

Macular Ganglion Cell Imaging Study: Covariate Effects on the Spectral Domain Optical Coherence Tomography for Glaucoma Diagnosis

PubMed Central

Jeong, Jae Hoon; Choi, Yun Jeong; Park, Ki Ho; Kim, Dong Myung

2016-01-01

Purpose To evaluate the effect of multiple covariates on the diagnostic performance of the Cirrus high-definition optical coherence tomography (HD-OCT) for glaucoma detection. Methods A prospective case-control study was performed and included 173 recently diagnosed glaucoma patients and 63 unaffected individuals from the Macular Ganglion Cell Imaging Study. Regression analysis of receiver operating characteristic were conducted to evaluate the influence of age, spherical equivalent, axial length, optic disc size, and visual field index on the macular ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (RNFL) measurements. Results Disease severity, as measured by visual field index, had a significant effect on the diagnostic performance of all Cirrus HD-OCT parameters. Age, axial length and optic disc size were significantly associated with diagnostic accuracy of average peripapillary RNFL thickness, whereas axial length had a significant effect on the diagnostic accuracy of average GCIPL thickness. Conclusions Diagnostic performance of the Cirrus HD-OCT may be more accurate in the advanced stages of glaucoma than at earlier stages. A smaller optic disc size was significantly associated with improved the diagnostic ability of average RNFL thickness measurements; however, GCIPL thickness may be less affected by age and optic disc size. PMID:27490718

Model Performance Evaluation and Scenario Analysis ...

EPA Pesticide Factsheets

This tool consists of two parts: model performance evaluation and scenario analysis (MPESA). The model performance evaluation consists of two components: model performance evaluation metrics and model diagnostics. These metrics provides modelers with statistical goodness-of-fit measures that capture magnitude only, sequence only, and combined magnitude and sequence errors. The performance measures include error analysis, coefficient of determination, Nash-Sutcliffe efficiency, and a new weighted rank method. These performance metrics only provide useful information about the overall model performance. Note that MPESA is based on the separation of observed and simulated time series into magnitude and sequence components. The separation of time series into magnitude and sequence components and the reconstruction back to time series provides diagnostic insights to modelers. For example, traditional approaches lack the capability to identify if the source of uncertainty in the simulated data is due to the quality of the input data or the way the analyst adjusted the model parameters. This report presents a suite of model diagnostics that identify if mismatches between observed and simulated data result from magnitude or sequence related errors. MPESA offers graphical and statistical options that allow HSPF users to compare observed and simulated time series and identify the parameter values to adjust or the input data to modify. The scenario analysis part of the too

Diagnostic Evaluation of Ozone Production and Horizontal Transport in a Regional Photochemical Air Quality Modeling System

EPA Science Inventory

A diagnostic model evaluation effort has been performed to focus on photochemical ozone formation and the horizontal transport process since they strongly impact the temporal evolution and spatial distribution of ozone (O₃) within the lower troposphere. Results from th...

Value of percutaneous needle biopsy of small renal tumors in patients referred for cryoablation.

PubMed

Iguchi, Toshihiro; Hiraki, Takao; Gobara, Hideo; Fujiwara, Hiroyasu; Sakurai, Jun; Matsui, Yusuke; Araki, Motoo; Nasu, Yasutomo; Kanazawa, Susumu

2017-04-01

To retrospectively evaluate the safety and diagnostic yield of needle biopsy of small renal tumors, and the clinical consequences of performing needle biopsy in patients referred for percutaneous cryoablation before their treatment. Biopsy was performed for 120 tumors (mean diameter, 2.2 cm) in 119 patients. All procedures were divided into diagnostic and non-diagnostic biopsies. Various variables were compared between the two groups. All cryoablation procedures were divided into two groups: procedures with or without simultaneous biopsy. The rates of benign or non-diagnostic tumors in each group were compared. After performing 120 initial and eight repeat biopsies, Grade 1 bleedings occurred in 44 cases. Six tumors were non-diagnostic and 114 were pathologically diagnosed. There were no significant variables between the diagnostic and non-diagnostic biopsies. Unnecessary cryoablation was avoided in nine benign lesions by performing biopsy in advance. Cryoablation performed simultaneously with biopsy included significantly more benign or non-diagnostic tumors than cryoablation performed after biopsy (15.2% vs. 1.4%; p = .01). Percutaneous biopsy of small renal tumors referred for cryoablation was a safe procedure with high diagnostic yield. The confirmation of pathological diagnosis prior to cryoablation is necessary because patients with benign tumors can avoid unnecessary treatment.

Influence of thyroid gland status on the thyroglobulin cutoff level in washout fluid from cervical lymph nodes of patients with recurrent/metastatic papillary thyroid cancer.

PubMed

Lee, Jun Ho; Lee, Hyun Chul; Yi, Ha Woo; Kim, Bong Kyun; Bae, Soo Youn; Lee, Se Kyung; Choe, Jun-Ho; Kim, Jung-Han; Kim, Jee Soo

2016-04-01

The influence of serum thyroglobulin (Tg) and thyroidectomy status on Tg in fine-needle aspiration cytology (FNAC) washout fluid is unclear. A total of 282 lymph nodes were prospectively subjected to FNAC, fine-needle aspiration (FNA)-Tg measurement, and frozen and permanent biopsies. We evaluated the diagnostic performance of several predetermined FNA-Tg cutoff values for recurrence/metastasis in lymph nodes according to thyroidectomy status. The diagnostic performance of FNA-Tg varied according to thyroidectomy status. The optimized cutoff value of FNA-Tg was 2.2 ng/mL. However, among FNAC-negative lymph nodes, the FNA-Tg cutoff value of 0.9 ng/mL showed better diagnostic performance in patients with a thyroid gland. An FNA-Tg/serum-Tg cutoff ratio of 1 showed the best diagnostic performance in patients without a thyroid gland. Applying the optimal cutoff values of FNA-Tg according to thyroid gland status and serum Tg level facilitates the diagnostic evaluation of neck lymph node recurrences/metastases in patients with papillary thyroid carcinoma (PTC). © 2015 Wiley Periodicals, Inc. Head Neck 38: E1705-E1712, 2016. © 2015 Wiley Periodicals, Inc.

Effects of disease severity distribution on the performance of quantitative diagnostic methods and proposal of a novel ‘V-plot’ methodology to display accuracy values

PubMed Central

Dehbi, Hakim-Moulay; Howard, James P; Shun-Shin, Matthew J; Sen, Sayan; Nijjer, Sukhjinder S; Mayet, Jamil; Davies, Justin E; Francis, Darrel P

2018-01-01

Background Diagnostic accuracy is widely accepted by researchers and clinicians as an optimal expression of a test’s performance. The aim of this study was to evaluate the effects of disease severity distribution on values of diagnostic accuracy as well as propose a sample-independent methodology to calculate and display accuracy of diagnostic tests. Methods and findings We evaluated the diagnostic relationship between two hypothetical methods to measure serum cholesterol (Cholrapid and Cholgold) by generating samples with statistical software and (1) keeping the numerical relationship between methods unchanged and (2) changing the distribution of cholesterol values. Metrics of categorical agreement were calculated (accuracy, sensitivity and specificity). Finally, a novel methodology to display and calculate accuracy values was presented (the V-plot of accuracies). Conclusion No single value of diagnostic accuracy can be used to describe the relationship between tests, as accuracy is a metric heavily affected by the underlying sample distribution. Our novel proposed methodology, the V-plot of accuracies, can be used as a sample-independent measure of a test performance against a reference gold standard. PMID:29387424

Develop Advanced Nonlinear Signal Analysis Topographical Mapping System

NASA Technical Reports Server (NTRS)

Jong, Jen-Yi

1997-01-01

During the development of the SSME, a hierarchy of advanced signal analysis techniques for mechanical signature analysis has been developed by NASA and AI Signal Research Inc. (ASRI) to improve the safety and reliability for Space Shuttle operations. These techniques can process and identify intelligent information hidden in a measured signal which is often unidentifiable using conventional signal analysis methods. Currently, due to the highly interactive processing requirements and the volume of dynamic data involved, detailed diagnostic analysis is being performed manually which requires immense man-hours with extensive human interface. To overcome this manual process, NASA implemented this program to develop an Advanced nonlinear signal Analysis Topographical Mapping System (ATMS) to provide automatic/unsupervised engine diagnostic capabilities. The ATMS will utilize a rule-based Clips expert system to supervise a hierarchy of diagnostic signature analysis techniques in the Advanced Signal Analysis Library (ASAL). ASAL will perform automatic signal processing, archiving, and anomaly detection/identification tasks in order to provide an intelligent and fully automated engine diagnostic capability. The ATMS has been successfully developed under this contract. In summary, the program objectives to design, develop, test and conduct performance evaluation for an automated engine diagnostic system have been successfully achieved. Software implementation of the entire ATMS system on MSFC's OISPS computer has been completed. The significance of the ATMS developed under this program is attributed to the fully automated coherence analysis capability for anomaly detection and identification which can greatly enhance the power and reliability of engine diagnostic evaluation. The results have demonstrated that ATMS can significantly save time and man-hours in performing engine test/flight data analysis and performance evaluation of large volumes of dynamic test data.

Evaluation of Rib Fractures on a Single-in-plane Image Reformation of the Rib Cage in CT Examinations.

PubMed

Dankerl, Peter; Seuss, Hannes; Ellmann, Stephan; Cavallaro, Alexander; Uder, Michael; Hammon, Matthias

2017-02-01

This study aimed to evaluate the diagnostic performance of using a reformatted single-in-plane image reformation of the rib cage for the detection of rib fractures in computed tomography (CT) examinations, employing different levels of radiological experience. We retrospectively evaluated 10 consecutive patients with and 10 patients without rib fractures, whose CT scans were reformatted to a single-in-plane image reformation of the rib cage. Eight readers (two radiologists, two residents in radiology, and four interns) independently evaluated the images for the presence of rib fractures using a reformatted single-in-plane image and a multi-planar image reformation. The time limit was 30 seconds for each read. A consensus of two radiologist readings was considered as the reference standard. Diagnostic performance (sensitivity, specificity, positive predictive value [PPV], and negative predictive value [NPV]) was assessed and evaluated per rib and per location (anterior, lateral, posterior). To determine the time limit, we prospectively analyzed the average time it took radiologists to assess the rib cage, in a bone window setting, in 50 routine CT examinations. McNemar test was used to compare the diagnostic performances. Single image reformation was successful in all 20 patients. The sensitivity, specificity, PPV, and NPV for the detection of rib fractures using the conventional multi-planar read were 77.5%, 99.2%, 89.9%, and 98.0% for radiologists; 46.3%, 99.7%, 92.5%, and 95.3% for residents; and 29.4%, 99.4%, 82.5%, and 93.9% for interns, respectively. Sensitivity, PPV, and NPV increased across all three groups of experience, using the reformatted single-in-plane image of the rib cage (radiologists: 85.0%, 98.6%, and 98.7%; residents: 80.0%, 92.8%, and 98.2%; interns: 66.9%, 89.9%, and 97.1%), whereas specificity did not change significantly (99.9%, 99.4%, and 99.3%). The diagnostic performance of the interns and residents was significantly better when evaluating the single-in-plane image reformations (P < .01). The diagnostic performance of the radiologists was better when evaluating the single-in-plane image reformations; however, there was no significant difference (statistical power: 0.32). The diagnostic performance for the detection of rib fractures, using CT images that have been reformatted to a single-in-plane image, improves for readers from different educational levels when the evaluation time is restricted to 30 seconds or less. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

A Meta-Analysis of Typhoid Diagnostic Accuracy Studies: A Recommendation to Adopt a Standardized Composite Reference

PubMed Central

Storey, Helen L.; Huang, Ying; Crudder, Chris; Golden, Allison; de los Santos, Tala; Hawkins, Kenneth

2015-01-01

Novel typhoid diagnostics currently under development have the potential to improve clinical care, surveillance, and the disease burden estimates that support vaccine introduction. Blood culture is most often used as the reference method to evaluate the accuracy of new typhoid tests; however, it is recognized to be an imperfect gold standard. If no single gold standard test exists, use of a composite reference standard (CRS) can improve estimation of diagnostic accuracy. Numerous studies have used a CRS to evaluate new typhoid diagnostics; however, there is no consensus on an appropriate CRS. In order to evaluate existing tests for use as a reference test or inclusion in a CRS, we performed a systematic review of the typhoid literature to include all index/reference test combinations observed. We described the landscape of comparisons performed, showed results of a meta-analysis on the accuracy of the more common combinations, and evaluated sources of variability based on study quality. This wide-ranging meta-analysis suggests that no single test has sufficiently good performance but some existing diagnostics may be useful as part of a CRS. Additionally, based on findings from the meta-analysis and a constructed numerical example demonstrating the use of CRS, we proposed necessary criteria and potential components of a typhoid CRS to guide future recommendations. Agreement and adoption by all investigators of a standardized CRS is requisite, and would improve comparison of new diagnostics across independent studies, leading to the identification of a better reference test and improved confidence in prevalence estimates. PMID:26566275

Diagnostic Performance of Electronic Syndromic Surveillance Systems in Acute Care

PubMed Central

Kashiouris, M.; O’Horo, J.C.; Pickering, B.W.; Herasevich, V.

2013-01-01

Context Healthcare Electronic Syndromic Surveillance (ESS) is the systematic collection, analysis and interpretation of ongoing clinical data with subsequent dissemination of results, which aid clinical decision-making. Objective To evaluate, classify and analyze the diagnostic performance, strengths and limitations of existing acute care ESS systems. Data Sources All available to us studies in Ovid MEDLINE, Ovid EMBASE, CINAHL and Scopus databases, from as early as January 1972 through the first week of September 2012. Study Selection: Prospective and retrospective trials, examining the diagnostic performance of inpatient ESS and providing objective diagnostic data including sensitivity, specificity, positive and negative predictive values. Data Extraction Two independent reviewers extracted diagnostic performance data on ESS systems, including clinical area, number of decision points, sensitivity and specificity. Positive and negative likelihood ratios were calculated for each healthcare ESS system. A likelihood matrix summarizing the various ESS systems performance was created. Results The described search strategy yielded 1639 articles. Of these, 1497 were excluded on abstract information. After full text review, abstraction and arbitration with a third reviewer, 33 studies met inclusion criteria, reporting 102,611 ESS decision points. The yielded I2 was high (98.8%), precluding meta-analysis. Performance was variable, with sensitivities ranging from 21% –100% and specificities ranging from 5%-100%. Conclusions There is significant heterogeneity in the diagnostic performance of the available ESS implements in acute care, stemming from the wide spectrum of different clinical entities and ESS systems. Based on the results, we introduce a conceptual framework using a likelihood ratio matrix for evaluation and meaningful application of future, frontline clinical decision support systems. PMID:23874359

Evaluating the performance of a fault detection and diagnostic system for vapor compression equipment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Breuker, M.S.; Braun, J.E.

This paper presents a detailed evaluation of the performance of a statistical, rule-based fault detection and diagnostic (FDD) technique presented by Rossi and Braun (1997). Steady-state and transient tests were performed on a simple rooftop air conditioner over a range of conditions and fault levels. The steady-state data without faults were used to train models that predict outputs for normal operation. The transient data with faults were used to evaluate FDD performance. The effect of a number of design variables on FDD sensitivity for different faults was evaluated and two prototype systems were specified for more complete evaluation. Good performancemore » was achieved in detecting and diagnosing five faults using only six temperatures (2 input and 4 output) and linear models. The performance improved by about a factor of two when ten measurements (three input and seven output) and higher order models were used. This approach for evaluating and optimizing the performance of the statistical, rule-based FDD technique could be used as a design and evaluation tool when applying this FDD method to other packaged air-conditioning systems. Furthermore, the approach could also be modified to evaluate the performance of other FDD methods.« less

Systematic review of dermoscopy and digital dermoscopy/ artificial intelligence for the diagnosis of melanoma.

PubMed

Rajpara, S M; Botello, A P; Townend, J; Ormerod, A D

2009-09-01

Dermoscopy improves diagnostic accuracy of the unaided eye for melanoma, and digital dermoscopy with artificial intelligence or computer diagnosis has also been shown useful for the diagnosis of melanoma. At present there is no clear evidence regarding the diagnostic accuracy of dermoscopy compared with artificial intelligence. To evaluate the diagnostic accuracy of dermoscopy and digital dermoscopy/artificial intelligence for melanoma diagnosis and to compare the diagnostic accuracy of the different dermoscopic algorithms with each other and with digital dermoscopy/artificial intelligence for the detection of melanoma. A literature search on dermoscopy and digital dermoscopy/artificial intelligence for melanoma diagnosis was performed using several databases. Titles and abstracts of the retrieved articles were screened using a literature evaluation form. A quality assessment form was developed to assess the quality of the included studies. Heterogeneity among the studies was assessed. Pooled data were analysed using meta-analytical methods and comparisons between different algorithms were performed. Of 765 articles retrieved, 30 studies were eligible for meta-analysis. Pooled sensitivity for artificial intelligence was slightly higher than for dermoscopy (91% vs. 88%; P = 0.076). Pooled specificity for dermoscopy was significantly better than artificial intelligence (86% vs. 79%; P < 0.001). Pooled diagnostic odds ratio was 51.5 for dermoscopy and 57.8 for artificial intelligence, which were not significantly different (P = 0.783). There were no significance differences in diagnostic odds ratio among the different dermoscopic diagnostic algorithms. Dermoscopy and artificial intelligence performed equally well for diagnosis of melanocytic skin lesions. There was no significant difference in the diagnostic performance of various dermoscopy algorithms. The three-point checklist, the seven-point checklist and Menzies score had better diagnostic odds ratios than the others; however, these results need to be confirmed by a large-scale high-quality population-based study.

Model Performance Evaluation and Scenario Analysis (MPESA) Tutorial

EPA Pesticide Factsheets

The model performance evaluation consists of metrics and model diagnostics. These metrics provides modelers with statistical goodness-of-fit measures that capture magnitude only, sequence only, and combined magnitude and sequence errors.

40 CFR 60.53b - Standards for municipal waste combustor operating practices.

Code of Federal Regulations, 2011 CFR

2011-07-01

... for the purpose of evaluating system performance, testing new technology or control technologies... evaluating system performance, testing new technology or control technologies, diagnostic testing, or related... (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of...

Salpingoscopy: systematic use in diagnostic laparoscopy.

PubMed

Marconi, G; Auge, L; Sojo, E; Young, E; Quintana, R

1992-04-01

To evaluate the importance of salpingoscopy together with laparoscopy in the diagnosis of tubal pathology. Salpingoscopy was performed as a complementary method in patients who were subjected to diagnostic laparoscopy. The relationship between the salpingoscopy and (1) the patient's previous history of tubal disease and (2) laparoscopic diagnoses was evaluated. Private patients referred to the Instituto de Fertilidad, Buenos Aires. Forty-two patients undergoing a diagnostic laparoscopy during the evaluation of their fertility or as a follow-up of previous therapy. Salpingoscopy was performed, using a colpomicrohysteroscope. We evaluated alterations in major and minor folds and their vascularization, the presence of microadhesions, and cellular nuclei dyed with methylene blue in the tubal lumen. Fifty percent of the patients who had no previous history of tubal disease presented with endosalpingeal alterations, and in 37% of the normal laparoscopies the salpinx had unilateral or bilateral salpingoscopic abnormalities. Salpingoscopy is a useful method to evaluate oviducts, before assuming their normality, and consideration of these women for assisted reproductive technology.

Benchmarking Diagnostic Algorithms on an Electrical Power System Testbed

NASA Technical Reports Server (NTRS)

Kurtoglu, Tolga; Narasimhan, Sriram; Poll, Scott; Garcia, David; Wright, Stephanie

2009-01-01

Diagnostic algorithms (DAs) are key to enabling automated health management. These algorithms are designed to detect and isolate anomalies of either a component or the whole system based on observations received from sensors. In recent years a wide range of algorithms, both model-based and data-driven, have been developed to increase autonomy and improve system reliability and affordability. However, the lack of support to perform systematic benchmarking of these algorithms continues to create barriers for effective development and deployment of diagnostic technologies. In this paper, we present our efforts to benchmark a set of DAs on a common platform using a framework that was developed to evaluate and compare various performance metrics for diagnostic technologies. The diagnosed system is an electrical power system, namely the Advanced Diagnostics and Prognostics Testbed (ADAPT) developed and located at the NASA Ames Research Center. The paper presents the fundamentals of the benchmarking framework, the ADAPT system, description of faults and data sets, the metrics used for evaluation, and an in-depth analysis of benchmarking results obtained from testing ten diagnostic algorithms on the ADAPT electrical power system testbed.

Spatial enhancement of ECG using diagnostic similarity score based lead selective multi-scale linear model.

PubMed

Nallikuzhy, Jiss J; Dandapat, S

2017-06-01

In this work, a new patient-specific approach to enhance the spatial resolution of ECG is proposed and evaluated. The proposed model transforms a three-lead ECG into a standard twelve-lead ECG thereby enhancing its spatial resolution. The three leads used for prediction are obtained from the standard twelve-lead ECG. The proposed model takes advantage of the improved inter-lead correlation in wavelet domain. Since the model is patient-specific, it also selects the optimal predictor leads for a given patient using a lead selection algorithm. The lead selection algorithm is based on a new diagnostic similarity score which computes the diagnostic closeness between the original and the spatially enhanced leads. Standard closeness measures are used to assess the performance of the model. The similarity in diagnostic information between the original and the spatially enhanced leads are evaluated using various diagnostic measures. Repeatability and diagnosability are performed to quantify the applicability of the model. A comparison of the proposed model is performed with existing models that transform a subset of standard twelve-lead ECG into the standard twelve-lead ECG. From the analysis of the results, it is evident that the proposed model preserves diagnostic information better compared to other models. Copyright © 2017 Elsevier Ltd. All rights reserved.

New methodology to baseline and match AME polysilicon etcher using advanced diagnostic tools

NASA Astrophysics Data System (ADS)

Poppe, James; Shipman, John; Reinhardt, Barbara E.; Roussel, Myriam; Hedgecock, Raymond; Fonda, Arturo

1999-09-01

As process controls tighten in the semiconductor industry, the need to understand the variables that determine system performance become more important. For plasma etch systems, process success depends on the control of key parameters such as: vacuum integrity, pressure, gas flows, and RF power. It is imperative to baseline, monitor, and control these variables. This paper presents an overview of the methods and tools used by Motorola BMC fabrication facility to characterize an Applied Materials polysilicon etcher. Tool performance data obtained from our traditional measurement techniques are limited in their scope and do not provide a complete picture of the ultimate tool performance. Presently the BMC traditional characterization tools provide a snapshot of the static operation of the equipment under test (EUT); however, complete evaluation of the dynamic performance cannot be monitored without the aid of specialized diagnostic equipment. To provide us with a complete system baseline evaluation of the polysilicon etcher, three diagnostic tools were utilized: Lucas Labs Vacuum Diagnostic System, Residual Gas Analyzer, and the ENI Voltage/Impedance Probe. The diagnostic methodology used to baseline and match key parameters of qualified production equipment has had an immense impact on other equipment characterization in the facility. It has resulted in reduced cycle time for new equipment introduction as well.

Endoscopic Ultrasound-guided Specimen Collection and Evaluation Techniques Affect Diagnostic Accuracy.

PubMed

Bang, Ji Young; Navaneethan, Udayakumar; Hasan, Muhammad K; Hawes, Robert; Varadarajulu, Shyam

2018-03-11

Outcomes of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) evaluation vary with technique, needles, and methods of specimen evaluation. We performed a direct comparison of diagnostic yields of EUS-FNA samples collected using different gauge needles (22- vs 25-gauge), with or without suction. We performed a randomized controlled study of 352 patients with suspected pancreatic masses, referred for EUS-FNA at a tertiary referral center. Patients were randomly assigned to 22-gauge needles with or without suction or 25-gauge needles with or without suction. Specimens were evaluated offsite by cell block and rapid onsite cytologic evaluation (ROSE). Final diagnoses were made based on histologic analyses or 12-month follow-up evaluations. The primary outcome was diagnostic adequacy of cell blocks. Secondary outcomes were operating characteristics of ROSE and EUS-FNA, number of passes required for accurate onsite diagnosis, and amount of blood in specimens. The final diagnoses were malignancy (81.5% of patients) and benign disease (17.0% of patients); 1.4% of patients were lost during follow up. Cell block, ROSE, and EUS-FNA led to diagnostic accuracies of 71.9%, 95.5%, and 96.6%, respectively. A 22-gauge needle with suction was associated with more passes for adequate onsite diagnosis (P = .003) and specimens contained more blood (P = .01). Diagnostic accuracy of specimens collected by transduodenal EUS-FNA was lower with 22-gauge needles with suction compared to other techniques (P = .004). In a randomized trial of patients undergoing EUS-FNA for pancreatic masses, samples collected with 22-gauge vs 25-gauge needles performed equally well for offsite specimen evaluation. Use of suction appears to increase number of passes needed and specimen bloodiness. Specimen collection techniques should be individualized based on method of evaluation. ClinicalTrials.gov no: NCT02424838. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Vehicle Integrated Prognostic Reasoner (VIPR) Metric Report

NASA Technical Reports Server (NTRS)

Cornhill, Dennis; Bharadwaj, Raj; Mylaraswamy, Dinkar

2013-01-01

This document outlines a set of metrics for evaluating the diagnostic and prognostic schemes developed for the Vehicle Integrated Prognostic Reasoner (VIPR), a system-level reasoner that encompasses the multiple levels of large, complex systems such as those for aircraft and spacecraft. VIPR health managers are organized hierarchically and operate together to derive diagnostic and prognostic inferences from symptoms and conditions reported by a set of diagnostic and prognostic monitors. For layered reasoners such as VIPR, the overall performance cannot be evaluated by metrics solely directed toward timely detection and accuracy of estimation of the faults in individual components. Among other factors, overall vehicle reasoner performance is governed by the effectiveness of the communication schemes between monitors and reasoners in the architecture, and the ability to propagate and fuse relevant information to make accurate, consistent, and timely predictions at different levels of the reasoner hierarchy. We outline an extended set of diagnostic and prognostics metrics that can be broadly categorized as evaluation measures for diagnostic coverage, prognostic coverage, accuracy of inferences, latency in making inferences, computational cost, and sensitivity to different fault and degradation conditions. We report metrics from Monte Carlo experiments using two variations of an aircraft reference model that supported both flat and hierarchical reasoning.

Combined evaluation of commonly used techniques, including PCR, for diagnosis of mouse fur mites.

PubMed

Karlsson, Eleanor M; Pearson, Laura M; Kuzma, Kristen M; Burkholder, Tanya H

2014-01-01

Our study evaluated and compared the false-negative rates (FNR) of a wide array of fur-mite diagnostic tests, including 2 postmortem tests (pelt exam and sticky paper) and 3 antemortem tests (adhesive tape, fur pluck, and PCR). Past publications examining fur-mite diagnostic techniques primarily used paired comparisons, evaluating tests by their level of agreement with only one other test. However, different combinations or pairs of diagnostics are used in the different studies, making the results of these comparisons difficult to interpret across all available diagnostics. In the current study, mice from a conventionally maintained colony endemic for Myobia musculi were identified as positive based on at least one positive diagnostic test. From this pool of positive animals, the FNR of all tests were quantified. The PCR assay and the pelt exam performed the best, with 0% and 2% FNR respectively, whereas tape, fur-pluck, and sticky-paper tests showed 24%, 26%, and 36% FNR, respectively. Our study shows that for mice in a colony naturally infested with Myobia musculi, PCR testing can be used for reliable antemortem detection, and pelt exam performed by experienced examiners is reliable for postmortem detection.

Spectral-domain Optical Coherence Tomography in Manifest Glaucoma: Its Additive Role in Structural Diagnosis.

PubMed

Kim, Ko Eun; Oh, Sohee; Jeoung, Jin Wook; Suh, Min Hee; Seo, Je Hyun; Kim, Martha; Park, Ki Ho; Kim, Dong Myung; Kim, Seok Hwan

2016-11-01

To investigate the additive role of spectral-domain optical coherence tomography (SDOCT) in the structural diagnosis in glaucoma. Reliability and validity analysis. Structural examinations from 109 eyes of 109 healthy individuals and 151 eyes of 151 glaucoma patients with different severities were included. Four structural-diagnostic examination sets were prepared using stereo-optic disc photography (SDP), red-free retinal nerve fiber layer photography (RNFLP), and SDOCT: (1) SDP (S), (2) SDP and SDOCT (SO), (3) SDP and RNFLP (SR), and (4) SDP, RNFLP, and SDOCT (SRO). Five glaucoma specialists were instructed to classify subjects as normal or glaucoma using each of the 4 diagnostic sets in the order S, SO, SR, and SRO, with a 1-month interval. The interobserver agreement was evaluated using kappa (κ) statistics. The additive effect of SDOCT on the diagnostic performance of the specialists was evaluated using the generalized estimating equation. Five glaucoma specialists showed an excellent level of interobserver agreement on the diagnostic assessments based on the 4 sets. In the comparison of the collective diagnostic performance of the specialists, addition of SDOCT to SDP showed an approximately 2-fold significant increase in the diagnostic accuracy. Adding SDOCT to SDP significantly enhanced the specialists' structural-diagnostic ability with respect to the moderate glaucoma, though not mild or advanced glaucoma. SDOCT significantly enhanced the diagnostic accuracy of the glaucoma specialists' performance, showing its additive diagnostic value in judging glaucomatous structural damage, especially in the moderate stage of glaucoma. Copyright © 2016 Elsevier Inc. All rights reserved.

Diagnostic Yield of Computed Tomography Scan for Pediatric Hearing Loss: A Systematic Review

PubMed Central

Chen, Jenny X.; Kachniarz, Bart; Shin, Jennifer J.

2015-01-01

Background Computed tomography (CT) has been used in the assessment of pediatric hearing loss, but concern regarding radiation risk and increased utilization of magnetic resonance imaging (MRI) have prompted us toward a more quantitative and sophisticated understanding of CT’s potential diagnostic yield. Objective To perform a systematic review to analyze the diagnostic yield of CT for pediatric hearing loss, including subgroup evaluation according to impairment severity and laterality, as well as the specific findings of enlarged vestibular aqueduct and narrow cochlear nerve canal. Data Sources PubMed, EMBASE, and the Cochrane Library were assessed from the date of their inception to December 2013. In addition, manual searches of bibliographies were performed and topic experts were contacted. Review Methods Data from studies describing the use of CT in the diagnostic evaluation of pediatric patients with hearing loss of unknown etiology were evaluated, according to a priori inclusion/exclusion criteria. Two independent evaluators corroborated the extracted data. Heterogeneity was evaluated according to the I2 statistic. Results In 50 criteria-meeting studies, the overall diagnostic yield of CT ranged from 7% to 74%, with the strongest and aggregate data demonstrating a point estimate of 30%. This estimate corresponded to a number needed to image of 4 (range, 2–15). The most commonly identified findings were enlarged vestibular aqueduct and cochlear anomalies. The largest studies showed a 4% to 7% yield for narrow cochlear nerve canal. Conclusion These data, along with similar analyses of radiation risk and risks/benefits of sedated MRI, may be used to help guide the choice of diagnostic imaging. PMID:25186339

Use of diagnostic accuracy as a metric for evaluating laboratory proficiency with microarray assays using mixed-tissue RNA reference samples.

PubMed

Pine, P S; Boedigheimer, M; Rosenzweig, B A; Turpaz, Y; He, Y D; Delenstarr, G; Ganter, B; Jarnagin, K; Jones, W D; Reid, L H; Thompson, K L

2008-11-01

Effective use of microarray technology in clinical and regulatory settings is contingent on the adoption of standard methods for assessing performance. The MicroArray Quality Control project evaluated the repeatability and comparability of microarray data on the major commercial platforms and laid the groundwork for the application of microarray technology to regulatory assessments. However, methods for assessing performance that are commonly applied to diagnostic assays used in laboratory medicine remain to be developed for microarray assays. A reference system for microarray performance evaluation and process improvement was developed that includes reference samples, metrics and reference datasets. The reference material is composed of two mixes of four different rat tissue RNAs that allow defined target ratios to be assayed using a set of tissue-selective analytes that are distributed along the dynamic range of measurement. The diagnostic accuracy of detected changes in expression ratios, measured as the area under the curve from receiver operating characteristic plots, provides a single commutable value for comparing assay specificity and sensitivity. The utility of this system for assessing overall performance was evaluated for relevant applications like multi-laboratory proficiency testing programs and single-laboratory process drift monitoring. The diagnostic accuracy of detection of a 1.5-fold change in signal level was found to be a sensitive metric for comparing overall performance. This test approaches the technical limit for reliable discrimination of differences between two samples using this technology. We describe a reference system that provides a mechanism for internal and external assessment of laboratory proficiency with microarray technology and is translatable to performance assessments on other whole-genome expression arrays used for basic and clinical research.

Diagnostic performance and color overlay pattern in shear wave elastography (SWE) for palpable breast mass.

PubMed

Park, Jiyoon; Woo, Ok Hee; Shin, Hye Seon; Cho, Kyu Ran; Seo, Bo Kyoung; Kang, Eun Young

2015-10-01

The purpose of this study is to evaluate the diagnostic performance of SWE in palpable breast mass and to compare with color overlay pattern in SWE with conventional US and quantitative SWE for assessing palpable breast mass. SWE and conventional breast US were performed in 133 women with 156 palpable breast lesions (81 benign, 75 malignant) between August 2013 to June 2014. Either pathology or periodic imaging surveillance more than 2 years was a reference standard. Existence of previous image was blinded to performing radiologists. US BI-RADS final assessment, qualitative and quantitative SWE measurements were evaluated. Diagnostic performances of grayscale US, SWE and US combined to SWE were calculated and compared. Correlation between pattern classification and quantitative SWE was evaluated. Both color overlay pattern and quantitative SWE improved the specificity of conventional US, from 81.48% to 96.30% (p=0.0005), without improvement in sensitivity. Color overlay pattern was significantly related to all quantitative SWE parameters and malignancy rate (p<0.0001.). The optimal cutoff of color overlay pattern was between 2 and 3. Emax with optimal cutoff at 45.1 kPa showed the highest Az value, sensitivity, specificity and accuracy among other quantitative SWE parameters (p<0.0001). Echogenic halo on grayscale US showed significant correlation with color overlay pattern and pathology (p<0.0001). In evaluation of palpable breast mass, conventional US combine to SWE improves specificity and reduces the number of biopsies that ultimately yield a benign result. Color overlay pattern classification is more quick and easy and may represent quantitative SWE measurements with similar diagnostic performances. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Diagnostic Performance of Narrow Band Imaging for Laryngeal Cancer: A Systematic Review and Meta-analysis.

PubMed

Sun, Changling; Han, Xue; Li, Xiaoying; Zhang, Yayun; Du, Xiaodong

2017-04-01

Objective To evaluate the performance of narrow band imaging (NBI) for the diagnosis of laryngeal cancer and to compare the diagnostic value of NBI with that of white light endoscopy. Data Sources PubMed, Embase, Cochrane Library, and CNKI databases. Review Methods Data analyses were performed with Meta-DiSc. The updated Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess study quality and potential bias. Publication bias was assessed with the Deeks's asymmetry test. The protocol used in this article has been published on PROSPERO and is in accordance with the PRISMA checklist. The registry number for this study is CRD42015025866. Results Six studies including 716 lesions were included in this meta-analysis. The pooled sensitivity, specificity, and diagnostic odds ratio for the NBI diagnosis of laryngeal cancer were 0.94 (95% confidence interval [95% CI]: 0.91-0.96), 0.89 (95% CI: 0.85-0.92), and 142.12 (95% CI: 46.42-435.15), respectively, and the area under receiver operating characteristics curve was 0.97. Among the 6 studies, 3 evaluated the diagnostic value of white light endoscopy, with a sensitivity of 0.81 (95% CI: 0.76-0.86), a specificity of 0.92 (95% CI: 0.88-0.95), and a diagnostic odds ratio of 33.82 (95% CI: 14.76-77.49). The evaluation of heterogeneity, calculated per the diagnostic odds ratio, gave an I 2 of 66%. No marked publication bias ( P = .84) was detected in this meta-analysis. Conclusion The sensitivity of NBI is superior to white light endoscopy, and the potential value of NBI needs to be validated in future studies.

Informativeness of Diagnostic Marker Values and the Impact of Data Grouping.

PubMed

Ma, Hua; Bandos, Andriy I; Gur, David

2018-01-01

Assessing performance of diagnostic markers is a necessary step for their use in decision making regarding various conditions of interest in diagnostic medicine and other fields. Globally useful markers could, however, have ranges of values that are " diagnostically non-informative" . This paper demonstrates that the presence of marker values from diagnostically non-informative ranges could lead to a loss in statistical efficiency during nonparametric evaluation and shows that grouping non-informative values provides a natural resolution to this problem. These points are theoretically proven and an extensive simulation study is conducted to illustrate the possible benefits of using grouped marker values in a number of practically reasonable scenarios. The results contradict the common conjecture regarding the detrimental effect of grouped marker values during performance assessments. Specifically, contrary to the common assumption that grouped marker values lead to bias, grouping non-informative values does not introduce bias and could substantially reduce sampling variability. The proven concept that grouped marker values could be statistically beneficial without detrimental consequences implies that in practice, tied values do not always require resolution whereas the use of continuous diagnostic results without addressing diagnostically non-informative ranges could be statistically detrimental. Based on these findings, more efficient methods for evaluating diagnostic markers could be developed.

Performance Evaluation of an Automated ELISA System for Alzheimer's Disease Detection in Clinical Routine.

PubMed

Chiasserini, Davide; Biscetti, Leonardo; Farotti, Lucia; Eusebi, Paolo; Salvadori, Nicola; Lisetti, Viviana; Baschieri, Francesca; Chipi, Elena; Frattini, Giulia; Stoops, Erik; Vanderstichele, Hugo; Calabresi, Paolo; Parnetti, Lucilla

2016-07-22

The variability of Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarkers undermines their full-fledged introduction into routine diagnostics and clinical trials. Automation may help to increase precision and decrease operator errors, eventually improving the diagnostic performance. Here we evaluated three new CSF immunoassays, EUROIMMUNtrademark amyloid-β 1-40 (Aβ1-40), amyloid-β 1-42 (Aβ1-42), and total tau (t-tau), in combination with automated analysis of the samples. The CSF biomarkers were measured in a cohort consisting of AD patients (n = 28), mild cognitive impairment (MCI, n = 77), and neurological controls (OND, n = 35). MCI patients were evaluated yearly and cognitive functions were assessed by Mini-Mental State Examination. The patients clinically diagnosed with AD and MCI were classified according to the CSF biomarkers profile following NIA-AA criteria and the Erlangen score. Technical evaluation of the immunoassays was performed together with the calculation of their diagnostic performance. Furthermore, the results for EUROIMMUN Aβ1-42 and t-tau were compared to standard immunoassay methods (INNOTESTtrademark). EUROIMMUN assays for Aβ1-42 and t-tau correlated with INNOTEST (r = 0.83, p < 0.001 for both) and allowed a similar interpretation of the CSF profiles. The Aβ1-42/Aβ1-40 ratio measured with EUROIMMUN was the best parameter for AD detection and improved the diagnostic accuracy of Aβ1-42 (area under the curve = 0.93). In MCI patients, the Aβ1-42/Aβ1-40 ratio was associated with cognitive decline and clinical progression to AD.The diagnostic performance of the EUROIMMUN assays with automation is comparable to other currently used methods. The variability of the method and the value of the Aβ1-42/Aβ1-40 ratio in AD diagnosis need to be validated in large multi-center studies.

Utility of DWI with quantitative ADC values in ovarian tumors: a meta-analysis of diagnostic test performance.

PubMed

Pi, Shan; Cao, Rong; Qiang, Jin Wei; Guo, Yan Hui

2018-01-01

Background Diffusion-weighted imaging (DWI) and quantitative apparent diffusion coefficient (ADC) values are widely used in the differential diagnosis of ovarian tumors. Purpose To assess the diagnostic performance of quantitative ADC values in ovarian tumors. Material and Methods PubMed, Embase, the Cochrane Library, and local databases were searched for studies assessing ovarian tumors using quantitative ADC values. We quantitatively analyzed the diagnostic performances for two clinical problems: benign vs. malignant tumors and borderline vs. malignant tumors. We evaluated diagnostic performances by the pooled sensitivity and specificity values and by summary receiver operating characteristic (SROC) curves. Subgroup analyses were used to analyze study heterogeneity. Results From the 742 studies identified in the search results, 16 studies met our inclusion criteria. A total of ten studies evaluated malignant vs. benign ovarian tumors and six studies assessed malignant vs. borderline ovarian tumors. Regarding the diagnostic accuracy of quantitative ADC values for distinguishing between malignant and benign ovarian tumors, the pooled sensitivity and specificity values were 0.91 and 0.91, respectively. The area under the SROC curve (AUC) was 0.96. For differentiating borderline from malignant tumors, the pooled sensitivity and specificity values were 0.89 and 0.79, and the AUC was 0.91. The methodological quality of the included studies was moderate. Conclusion Quantitative ADC values could serve as useful preoperative markers for predicting the nature of ovarian tumors. Nevertheless, prospective trials focused on standardized imaging parameters are needed to evaluate the clinical value of quantitative ADC values in ovarian tumors.

A tutorial on the use of ROC analysis for computer-aided diagnostic systems.

PubMed

Scheipers, Ulrich; Perrey, Christian; Siebers, Stefan; Hansen, Christian; Ermert, Helmut

2005-07-01

The application of the receiver operating characteristic (ROC) curve for computer-aided diagnostic systems is reviewed. A statistical framework is presented and different methods of evaluating the classification performance of computer-aided diagnostic systems, and, in particular, systems for ultrasonic tissue characterization, are derived. Most classifiers that are used today are dependent on a separation threshold, which can be chosen freely in many cases. The separation threshold separates the range of output values of the classification system into different target groups, thus conducting the actual classification process. In the first part of this paper, threshold specific performance measures, e.g., sensitivity and specificity, are presented. In the second part, a threshold-independent performance measure, the area under the ROC curve, is reviewed. Only the use of separation threshold-independent performance measures provides classification results that are overall representative for computer-aided diagnostic systems. The following text was motivated by the lack of a complete and definite discussion of the underlying subject in available textbooks, references and publications. Most manuscripts published so far address the theme of performance evaluation using ROC analysis in a manner too general to be practical for everyday use in the development of computer-aided diagnostic systems. Nowadays, the user of computer-aided diagnostic systems typically handles huge amounts of numerical data, not always distributed normally. Many assumptions made in more or less theoretical works on ROC analysis are no longer valid for real-life data. The paper aims at closing the gap between theoretical works and real-life data. The review provides the interested scientist with information needed to conduct ROC analysis and to integrate algorithms performing ROC analysis into classification systems while understanding the basic principles of classification.

Initial clinical experience with a 64-MDCT whole-body scanner in an emergency department: better time management and diagnostic quality?

PubMed

Rieger, Michael; Czermak, Benedikt; El Attal, Rene; Sumann, Günther; Jaschke, Werner; Freund, Martin

2009-03-01

The objective of this study was to assess time management and diagnostic quality when using a 64-multidetector-row computed tomography (MDCT) whole-body scanner to evaluate polytraumatized patients in an emergency department. Eighty-eight consecutive polytraumatized patients with injury severity score (ISS) > or = 18 (mean ISS = 29) were included in this study. Documented and evaluated data were crash history, trauma mechanism, number and pattern of injuries, injury severity, diagnostics, time flow, and missed diagnoses. Data were stored in our hospital information system. Seven time intervals were evaluated. In particular, attention was paid to the "acquisition interval," the "reformatting and evaluation time" as well as the "CT time" (time from CT start to preliminary diagnosis). A standardized whole-body CT was performed. The acquired CT data together with automatically generated multiplanar reformatted images ("direct MPR") were transferred to a 3D rendering workstation. Diagnostic quality was determined on the basis of missed diagnoses. Head-to-toe scout images were possible because volume coverage was up to 2 m. Experienced radiologists at an affiliated workstation performed radiologic evaluation of the acquired datasets immediately after acquisition. The "acquisition interval" was 12 minutes +/- 4.9 minutes, the "reformatting and evaluation interval" 7.0 minutes +/- 2.1 minutes, and the "CT time" 19 minutes +/- 6.1 minutes. Altogether, 7 of 486 lesions were recognized but not communicated in the "reformatting and evaluation interval", and 10 injuries were initially missed and detected during follow-up. This study indicates that 64-MDCT saves time, especially in the "reformatting and evaluation interval." Diagnostic quality is high, as reflected by the small number of missed diagnoses.

Diagnostic Performance of the CBCL-Attention Problem Scale as a Screening Measure in a Sample of Brazilian Children with ADHD

ERIC Educational Resources Information Center

Lampert, T. L.; Polanczyk, G.; Tramontina, S.; Mardini, V.; Rohde, L. A.

2004-01-01

Objective: To evaluate the diagnostic performance of the Attention Problem Scale of the Child Behavior Checklist (CBCL-APS) for the screening of Attention-Deficit/Hyperactivity Disorder (ADHD) in a sample of Brazilian children and adolescents. Methods: The CBCL-APS was given to 763 children and adolescents. Child psychiatrists using DSM-IV…

Diagnostic Ability of Automated Pupillography in Glaucoma.

PubMed

Rao, Harsha L; Kadambi, Sujatha V; Mehta, Pooja; Dasari, Srilakshmi; Puttaiah, Narendra K; Pradhan, Zia S; Rao, Dhanraj A S; Shetty, Rohit

2017-05-01

To evaluate the diagnostic ability of automated pupillography measurements in glaucoma and study the effect of inter-eye asymmetry in glaucomatous damage on the diagnostic ability. In an observational, cross-sectional study, 47 glaucoma patients and 42 control subjects underwent automated pupillography using a commercially available device. Diagnostic abilities of the pupillary response measurements were evaluated using area under receiver operating characteristic (ROC) curves (AUC) and sensitivities at fixed specificities. Influence of inter-eye asymmetry in glaucoma [inter-eye mean deviation (MD) difference on visual fields (VF)] on the diagnostic ability of pupillography parameters was evaluated by ROC regression approach. The AUCs of automated pupillography parameters ranged from 0.60 (amplitude score with peripheral blue stimulus) to 0.82 (amplitude score with full field white stimulus, Amp-FF-W). Sensitivity at 95% specificity ranged between 5% (amplitude score with full field blue stimulus) and 45% (amplitude score with full field green stimulus). Inter-eye MD difference significantly affected the diagnostic performance of automated pupillography parameters (p < 0.05). AUCs of Amp-FF-W at inter-eye MD difference of 0 dB, 5 dB, 10 dB and 15 dB were 0.71, 0.80, 0.87 and 0.93, respectively, according to the regression model. The corresponding sensitivities at 95% specificity were 20%, 34%, 50% and 66%, respectively. The diagnostic abilities of even the best automated pupillography parameters were only moderate in glaucoma. The performance of these pupillography measurements in detecting glaucoma significantly increased with greater inter-eye asymmetry in the glaucomatous damage.

How to Perform a Systematic Review and Meta-analysis of Diagnostic Imaging Studies.

PubMed

Cronin, Paul; Kelly, Aine Marie; Altaee, Duaa; Foerster, Bradley; Petrou, Myria; Dwamena, Ben A

2018-05-01

A systematic review is a comprehensive search, critical evaluation, and synthesis of all the relevant studies on a specific (clinical) topic that can be applied to the evaluation of diagnostic and screening imaging studies. It can be a qualitative or a quantitative (meta-analysis) review of available literature. A meta-analysis uses statistical methods to combine and summarize the results of several studies. In this review, a 12-step approach to performing a systematic review (and meta-analysis) is outlined under the four domains: (1) Problem Formulation and Data Acquisition, (2) Quality Appraisal of Eligible Studies, (3) Statistical Analysis of Quantitative Data, and (4) Clinical Interpretation of the Evidence. This review is specifically geared toward the performance of a systematic review and meta-analysis of diagnostic test accuracy (imaging) studies. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Evaluation of Raman spectroscopy in comparison to commonly performed dengue diagnostic tests

NASA Astrophysics Data System (ADS)

Khan, Saranjam; Ullah, Rahat; Khurram, Muhammad; Ali, Hina; Mahmood, Arshad; Khan, Ajmal; Ahmed, Mushtaq

2016-09-01

This study demonstrates the evaluation of Raman spectroscopy as a rapid diagnostic test in comparison to commonly performed tests for an accurate detection of dengue fever in human blood sera. Blood samples of 104 suspected dengue patients collected from Holy Family Hospital, Rawalpindi, Pakistan, have been used in this study. Out of 104 samples, 52 (50%) were positive based on immunoglobulin G (IgG), whereas 54 (52%) were positive based on immunoglobulin M (IgM) antibody tests. For the determination of the diagnostic capabilities of Raman spectroscopy, accuracy, sensitivity, specificity and false positive rate have been calculated in comparison to normally performed IgM and IgG captured enzyme-linked immunosorbent assay tests. Accuracy, precision, specificity, and sensitivity for Raman spectroscopy in comparison to IgM were found to be 66%, 70%, 72%, and 61%, whereas based on IgG they were 47%, 46%, 52%, and 43%, respectively.

Real-time elastography in the evaluation of diffuse thyroid disease: a study based on elastography histogram parameters.

PubMed

Yoon, Jung Hyun; Yoo, Jaeheung; Kim, Eun-Kyung; Moon, Hee Jung; Lee, Hye Sun; Seo, Jae Young; Park, Hye Young; Park, Woon-Ju; Kwak, Jin Young

2014-09-01

The purpose of this study was to evaluate the diagnostic performance of quantitative histogram parameters using real-time tissue elastography (RTE) in the diagnosis of patients with diffuse thyroid disease. One hundred and sixteen patients (mean age, 43.7 ± 10.97 y) who had undergone pre-operative staging ultrasonography and RTE were included. For each patient, 11 parameters were obtained from RTE images, from which the "elastic index" was calculated. Diagnostic performance of the elastic index and that of the 11 parameters on RTE were calculated and compared. Of the 116 patients, 31 had diffuse thyroid disease and 85 had normal thyroid parenchyma. Area under the receiver operating characteristic curve (A(z)) of MEAN (average relative value) elasticity was high (0.737), without significant differences from other elasticity values. Diagnostic performance of the elastic index was higher than the MEAN, A(z) = 0.753, without significance (p = 0.802). In conclusion, RTE using the elastic index was found to have good diagnostic performance and may be useful in the diagnosis and management of patients with diffuse thyroid disease. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Measures to Improve Diagnostic Safety in Clinical Practice

PubMed Central

Singh, Hardeep; Graber, Mark L; Hofer, Timothy P

2016-01-01

Timely and accurate diagnosis is foundational to good clinical practice and an essential first step to achieving optimal patient outcomes. However, a recent Institute of Medicine report concluded that most of us will experience at least one diagnostic error in our lifetime. The report argues for efforts to improve the reliability of the diagnostic process through better measurement of diagnostic performance. The diagnostic process is a dynamic team-based activity that involves uncertainty, plays out over time, and requires effective communication and collaboration among multiple clinicians, diagnostic services, and the patient. Thus, it poses special challenges for measurement. In this paper, we discuss how the need to develop measures to improve diagnostic performance could move forward at a time when the scientific foundation needed to inform measurement is still evolving. We highlight challenges and opportunities for developing potential measures of “diagnostic safety” related to clinical diagnostic errors and associated preventable diagnostic harm. In doing so, we propose a starter set of measurement concepts for initial consideration that seem reasonably related to diagnostic safety, and call for these to be studied and further refined. This would enable safe diagnosis to become an organizational priority and facilitate quality improvement. Health care systems should consider measurement and evaluation of diagnostic performance as essential to timely and accurate diagnosis and to the reduction of preventable diagnostic harm. PMID:27768655

A new full-field digital mammography system with and without the use of an advanced post-processing algorithm: comparison of image quality and diagnostic performance.

PubMed

Ahn, Hye Shin; Kim, Sun Mi; Jang, Mijung; Yun, Bo La; Kim, Bohyoung; Ko, Eun Sook; Han, Boo-Kyung; Chang, Jung Min; Yi, Ann; Cho, Nariya; Moon, Woo Kyung; Choi, Hye Young

2014-01-01

To compare new full-field digital mammography (FFDM) with and without use of an advanced post-processing algorithm to improve image quality, lesion detection, diagnostic performance, and priority rank. During a 22-month period, we prospectively enrolled 100 cases of specimen FFDM mammography (Brestige®), which was performed alone or in combination with a post-processing algorithm developed by the manufacturer: group A (SMA), specimen mammography without application of "Mammogram enhancement ver. 2.0"; group B (SMB), specimen mammography with application of "Mammogram enhancement ver. 2.0". Two sets of specimen mammographies were randomly reviewed by five experienced radiologists. Image quality, lesion detection, diagnostic performance, and priority rank with regard to image preference were evaluated. Three aspects of image quality (overall quality, contrast, and noise) of the SMB were significantly superior to those of SMA (p < 0.05). SMB was significantly superior to SMA for visualizing calcifications (p < 0.05). Diagnostic performance, as evaluated by cancer score, was similar between SMA and SMB. SMB was preferred to SMA by four of the five reviewers. The post-processing algorithm may improve image quality with better image preference in FFDM than without use of the software.

Recall Tests Are Effective to Detect Mild Cognitive Impairment: A Systematic Review and Meta-analysis of 108 Diagnostic Studies.

PubMed

Tsoi, Kelvin K F; Chan, Joyce Y C; Hirai, Hoyee W; Wong, Adrian; Mok, Vincent C T; Lam, Linda C W; Kwok, Timothy C Y; Wong, Samuel Y S

2017-09-01

Mild cognitive impairment (MCI) is a prevalent symptom associated with the increased risk of dementia. There are many cognitive tests available for detection of MCI, and investigation of the diagnostic performance of the tests is deemed necessary. This study aims to evaluate the diagnostic performance of different cognitive tests used for MCI detection. A list of cognitive tests was identified in previous reviews and from online search engines. Literature searches were performed on each of the cognitive tests in MEDLINE, Embase, and PsycINFO from the earliest available dates of individual databases to December 31, 2016. Google Scholar was used as a supplementary search tool. Studies that were used to assess the diagnostic performance of the cognitive tests were extracted with inclusion and exclusion criteria. Each test's performance was compared with the standard diagnostic criteria. Bivariate random effects models were used to summarize the test performance as a point estimate for sensitivity and specificity, and presented in a summary receiver operating characteristic curve. Reporting quality and risk of bias were evaluated. A total of 108 studies with 23,546 participants were selected to evaluate 9 cognitive tests for MCI detection. Most of the studies used the Mini-Mental State Examination (MMSE) (n = 58) and the Montreal Cognitive Assessment (MoCA) (n = 35). The combined diagnostic performance of the MMSE in MCI detection was 0.71 sensitivity [95% confidence interval (CI): 0.66-0.75] and 0.74 specificity (95% CI: 0.70-0.78), and of the MoCA in MCI detection was 0.83 sensitivity (95% CI: 0.80-0.86) and 0.75 specificity (95% CI: 0.69-0.80). Among the 9 cognitive tests, recall tests showed the best diagnostic performance with 0.89 sensitivity (95% CI: 0.86-0.92) and 0.84 specificity (95% CI, 0.79-0.89). In subgroup analyses, long- or short-delay recall tests have shown better performance than immediate recall tests. Recall tests were shown to be the most effective test in MCI detection, especially for the population with symptoms of memory deterioration. They can be potentially used as the triage screening test for MCI in primary care setting. But when a patient shows cognitive impairments beyond memory deterioration, a more comprehensive test such as the MoCA should be used. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Multicenter Evaluation Of Coronary Dual-Source CT angiography in patients with intermediate Risk of Coronary Artery Stenoses (MEDIC): study design and rationale.

PubMed

Marwan, Mohamed; Hausleiter, Jörg; Abbara, Suhny; Hoffmann, Udo; Becker, Christoph; Ovrehus, Kristian; Ropers, Dieter; Bathina, Ravi; Berman, Dan; Anders, Katharina; Uder, Michael; Meave, Aloha; Alexánderson, Erick; Achenbach, Stephan

2014-01-01

The diagnostic performance of multidetector row CT to detect coronary artery stenosis has been evaluated in numerous single-center studies, with only limited data from large cohorts with low-to-intermediate likelihood of coronary disease and in multicenter trials. The Multicenter Evaluation of Coronary Dual-Source CT Angiography in Patients with Intermediate Risk of Coronary Artery Stenoses (MEDIC) trial determines the accuracy of dual-source CT (DSCT) to identify persons with at least 1 coronary artery stenosis among patients with low-to-intermediate pretest likelihood of disease. The MEDIC trial was designed as a prospective, multicenter, international trial to evaluate the diagnostic performance of DSCT for the detection of coronary artery stenosis compared with invasive coronary angiography. The study includes 8 sites in Germany, India, Mexico, the United States, and Denmark. The study population comprises patients referred for a diagnostic coronary angiogram because of suspected coronary artery disease with an intermediate pretest likelihood as determined by sex, age, and symptoms. All evaluations are performed by blinded core laboratory readers. The primary outcome of the MEDIC trial is the accuracy of DSCT to identify the presence of coronary artery stenoses with a luminal diameter narrowing of 50% or more on a per-vessel basis. Secondary outcome parameters include per-patient and per-segment diagnostic accuracy for 50% stenoses and accuracy to identify stenoses of 70% or more. Furthermore, secondary outcome parameters include the influence of heart rate, Agatston score, body weight, body mass index, image quality, and diagnostic confidence on the accuracy to detect coronary artery stenoses >50% on a per-vessel basis. The results of the MEDIC trial will assess the clinical utility of coronary CT angiography in the evaluation of patients with intermediate pretest likelihood of coronary artery disease. Copyright © 2014 Society of Cardiovascular Computed Tomography. All rights reserved.

CT fluoroscopy-guided renal tumour cutting needle biopsy: retrospective evaluation of diagnostic yield, safety, and risk factors for diagnostic failure.

PubMed

Iguchi, Toshihiro; Hiraki, Takao; Matsui, Yusuke; Fujiwara, Hiroyasu; Sakurai, Jun; Masaoka, Yoshihisa; Gobara, Hideo; Kanazawa, Susumu

2018-01-01

To evaluate retrospectively the diagnostic yield, safety, and risk factors for diagnostic failure of computed tomography (CT) fluoroscopy-guided renal tumour biopsy. Biopsies were performed for 208 tumours (mean diameter 2.3 cm; median diameter 2.1 cm; range 0.9-8.5 cm) in 199 patients. One hundred and ninety-nine tumours were ≤4 cm. All 208 initial procedures were divided into diagnostic success and failure groups. Multiple variables related to the patients, lesions, and procedures were assessed to determine the risk factors for diagnostic failure. After performing 208 initial and nine repeat biopsies, 180 malignancies and 15 benign tumours were pathologically diagnosed, whereas 13 were not diagnosed. In 117 procedures, 118 Grade I and one Grade IIIa adverse events (AEs) occurred. Neither Grade ≥IIIb AEs nor tumour seeding were observed within a median follow-up period of 13.7 months. Logistic regression analysis revealed only small tumour size (≤1.5 cm; odds ratio 3.750; 95% confidence interval 1.362-10.326; P = 0.011) to be a significant risk factor for diagnostic failure. CT fluoroscopy-guided renal tumour biopsy is a safe procedure with a high diagnostic yield. A small tumour size (≤1.5 cm) is a significant risk factor for diagnostic failure. • CT fluoroscopy-guided renal tumour biopsy has a high diagnostic yield. • CT fluoroscopy-guided renal tumour biopsy is safe. • Small tumour size (≤1.5 cm) is a risk factor for diagnostic failure.

Diagnostic Lumbar Puncture

PubMed Central

Doherty, Carolynne M; Forbes, Raeburn B

2014-01-01

Diagnostic Lumbar Puncture is one of the most commonly performed invasive tests in clinical medicine. Evaluation of an acute headache and investigation of inflammatory or infectious disease of the nervous system are the most common indications. Serious complications are rare, and correct technique will minimise diagnostic error and maximise patient comfort. We review the technique of diagnostic Lumbar Puncture including anatomy, needle selection, needle insertion, measurement of opening pressure, Cerebrospinal Fluid (CSF) specimen handling and after care. We also make some quality improvement suggestions for those designing services incorporating diagnostic Lumbar Puncture. PMID:25075138

Inadequate Diagnostic Evaluation in Young Patients Registered with a Diagnosis of Dementia: A Nationwide Register-Based Study

PubMed Central

Salem, Lise Cronberg; Andersen, Birgitte Bo; Nielsen, T. Rune; Stokholm, Jette; Jørgensen, Martin Balslev; Waldemar, Gunhild

2014-01-01

Background Establishing a diagnosis of dementia in young patients may be complex and have significant implications for the patient. The aim of this study was to evaluate the quality of the diagnostic work-up in young patients diagnosed with dementia in the clinical routine. Methods Two hundred patients were randomly selected from 891 patients aged ≤65 years registered with a diagnosis of dementia for the first time in 2008 in Danish hospitals, and 159 medical records were available for review. Three raters evaluated their medical records for the completeness of the diagnostic work-up on which the diagnosis of dementia had been based, using evidence-based guidelines for the diagnostic evaluation of dementia as reference standards. Results According to the rater review, only 111 (70%) patients met the clinical criteria for dementia. An acceptable diagnostic work-up including all items of recommended basic diagnostic evaluation was performed in only 24%, although more often (28%) in the subgroup of patients where dementia was confirmed by raters. Conclusion This first nationwide study of unselected young patients registered with a diagnosis of dementia indicated that the concept of dementia may be misinterpreted by clinicians and that a diagnosis of dementia in the young is only rarely based on a complete basic diagnostic work-up, calling for increased competency. PMID:24711812

Three-phase bone scintigraphy for diagnosis of Charcot neuropathic osteoarthropathy in the diabetic foot - does quantitative data improve diagnostic value?

PubMed

Fosbøl, M; Reving, S; Petersen, E H; Rossing, P; Lajer, M; Zerahn, B

2017-01-01

To investigate whether inclusion of quantitative data on blood flow distribution compared with visual qualitative evaluation improve the reliability and diagnostic performance of 99 m Tc-hydroxymethylene diphosphate three-phase bone scintigraphy (TPBS) in patients suspected for charcot neuropathic osteoarthropathy (CNO) of the foot. A retrospective cohort study of TPBS performed on 148 patients with suspected acute CNO referred from a single specialized diabetes care centre. The quantitative blood flow distribution was calculated based on the method described by Deutsch et al. All scintigraphies were re-evaluated by independent, blinded observers twice with and without quantitative data on blood flow distribution at ankle and focus level, respectively. The diagnostic validity of TPBS was determined by subsequent review of clinical data and radiological examinations. A total of 90 patients (61%) had confirmed diagnosis of CNO. The sensitivity, specificity and accuracy of three-phase bone scintigraphy without/with quantitative data were 89%/88%, 58%/62% and 77%/78%, respectively. The intra-observer agreement improved significantly by adding quantitative data in the evaluation (Kappa value 0·79/0·94). The interobserver agreement was not significantly improved. Adding quantitative data on blood flow distribution in the interpretation of TBPS improves intra-observer variation, whereas no difference in interobserver variation was observed. The sensitivity of TPBS in the diagnosis of CNO is high, but holds limited specificity. Diagnostic performance does not improve using quantitative data in the evaluation. This may be due to the reference intervals applied in the study or the absence of a proper gold standard diagnostic procedure for comparison. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Diagnosis of sub-centimetre breast lesions: combining BI-RADS-US with strain elastography and contrast-enhanced ultrasound-a preliminary study in China.

PubMed

Xiao, Xiaoyun; Jiang, Qiongchao; Wu, Huan; Guan, Xiaofeng; Qin, Wei; Luo, Baoming

2017-06-01

To compare the diagnostic efficacies of B-mode ultrasound (US), strain elastography (SE), contrast-enhanced ultrasound (CEUS) and the combination of these modalities for breast lesions <1 cm in size. Between January 2013 and October 2015, 203 inpatients with 209 sub-centimetre breast lesions categorised as BI-RADS-US (Breast Imaging Reporting and Data System for Ultrasound) 3-5 were included. US, SE and CEUS were performed to evaluate each lesion. The diagnostic performances of different ultrasonic modalities were compared. The diagnostic efficacies of BI-RADS-US and our re-rating systems were also compared. The pathology findings were used as the reference standard. The specificities of US, SE and CEUS for tumour differentiation were 17.4 %, 56.2 % and 86.0 %, respectively (P < 0.05); and the sensitivities were 100 %, 93.2 % and 93.2 % for US, SE and CEUS, respectively (P < 0.05). The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was 0.867 for original BI-RADS-US, 0.882 for BI-RADS-US combined with only SE, 0.953 for BI-RADS-US combined with only CEUS and 0.924 for BI-RADS-US combined with both SE and CEUS. The best combination was BI-RADS-US combined with only CEUS. Evaluating sub-centimetre breast lesions with SE and CEUS could increase the diagnostic specificity while retaining high sensitivity compared with B-mode ultrasound. • Evaluating breast lesions with SE and CEUS could increase the diagnostic specificity • SE and CEUS offer alternatives to biopsy and possibly allow shorter-interval follow-ups • BI-RADS-US combined with CEUS exhibited the best diagnostic performance.

A Hybrid Neural Network-Genetic Algorithm Technique for Aircraft Engine Performance Diagnostics

NASA Technical Reports Server (NTRS)

Kobayashi, Takahisa; Simon, Donald L.

2001-01-01

In this paper, a model-based diagnostic method, which utilizes Neural Networks and Genetic Algorithms, is investigated. Neural networks are applied to estimate the engine internal health, and Genetic Algorithms are applied for sensor bias detection and estimation. This hybrid approach takes advantage of the nonlinear estimation capability provided by neural networks while improving the robustness to measurement uncertainty through the application of Genetic Algorithms. The hybrid diagnostic technique also has the ability to rank multiple potential solutions for a given set of anomalous sensor measurements in order to reduce false alarms and missed detections. The performance of the hybrid diagnostic technique is evaluated through some case studies derived from a turbofan engine simulation. The results show this approach is promising for reliable diagnostics of aircraft engines.

An FDA Perspective on the Regulatory Implications of Complex Signatures to Predict Response to Targeted Therapies

PubMed Central

Beaver, Julia A.; Tzou, Abraham; Blumenthal, Gideon M.; McKee, Amy E.; Kim, Geoffrey; Pazdur, Richard; Philip, Reena

2016-01-01

As technologies evolve, and diagnostics move from detection of single biomarkers toward complex signatures, an increase in the clinical use and regulatory submission of complex signatures is anticipated. However, to date, no complex signatures have been approved as companion diagnostics. In this article, we will describe the potential benefit of complex signatures and their unique regulatory challenges including analytical performance validation, complex signature simulation, and clinical performance evaluation. We also will review the potential regulatory pathways for clearance, approval, or acceptance of complex signatures by the U.S. Food and Drug Administration (FDA). These regulatory pathways include regulations applicable to in vitro diagnostic devices, including companion diagnostic devices, the potential for labeling as a complementary diagnostic, and the biomarker qualification program. PMID:27993967

[Etiology and diagnostic methods in vocal cord paralysis].

PubMed

Jørgensen, Gita; Clausen, Eva Wiinstedt; Mantoni, Margit Y; Misciattelli, Lorenzo; Balle, Viggo

2003-02-10

The etiology of vocal cord paralysis (VCP) is varied. There is lack of consensus regarding the choice of investigations to be used in the evaluation of VCP. The aim of this study was to establish the etiology, assess the diagnostic methods used in the evaluation, and outline an algorithm for future evaluation of unilateral vocal cord paralysis (UVCP). Charts of all patients (n = 94) with the diagnostic code of VCP were reviewed, and reexaminations were performed of patients in whom no etiology was found after the initial symptoms. The etiology of UVCP was neoplasm in 34%, surgical trauma in 12%, and miscellaneous causes in 54%. The etiology of bilateral vocal cord paralysis (BVCP) was neoplasm in 24%, surgical trauma in 24%, and miscellaneous causes in 52%. The reexaminations did not reveal any cancer diseases in the patients concerned. The most effective diagnostic method was CT-scanning while the least effective was thyroid scanning. Because cancer is a common cause of VCP a thorough evaluation is necessary. For UVCP we recommend history and physical examination, X-ray of the chest, ultrasonography of the neck, and CT-scanning of the superior mediastinum. If these prove negative, panendoscopy should be performed. Workup of patients with idiopathic VCP should include examination, X-ray of the chest at 6-month intervals, and annual CT-scanning for two years.

Diagnostic performance of traditional hepatobiliary biomarkers of drug-induced liver injury in the rat.

PubMed

Ennulat, Daniela; Magid-Slav, Michal; Rehm, Sabine; Tatsuoka, Kay S

2010-08-01

Nonclinical studies provide the opportunity to anchor biochemical with morphologic findings; however, liver injury is often complex and heterogeneous, confounding the ability to relate biochemical changes with specific patterns of injury. The aim of the current study was to compare diagnostic performance of hepatobiliary markers for specific manifestations of drug-induced liver injury in rat using data collected in a recent hepatic toxicogenomics initiative in which rats (n = 3205) were given 182 different treatments for 4 or 14 days. Diagnostic accuracy of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (Tbili), serum bile acids (SBA), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT), total cholesterol (Chol), and triglycerides (Trig) was evaluated for specific types of liver histopathology by Receiver Operating Characteristic (ROC) analysis. To assess the relationship between biochemical and morphologic changes in the absence of hepatocellular necrosis, a second ROC analysis was performed on a subset of rats (n = 2504) given treatments (n = 152) that did not cause hepatocellular necrosis. In the initial analysis, ALT, AST, Tbili, and SBA had the greatest diagnostic utility for manifestations of hepatocellular necrosis and biliary injury, with comparable magnitude of area under the ROC curve and serum hepatobiliary marker changes for both. In the absence of hepatocellular necrosis, ALT increases were observed with biochemical or morphologic evidence of cholestasis. In both analyses, diagnostic utility of ALP and GGT for biliary injury was limited; however, ALP had modest diagnostic value for peroxisome proliferation, and ALT, AST, and total Chol had moderate diagnostic utility for phospholipidosis. None of the eight markers evaluated had diagnostic value for manifestations of hypertrophy, cytoplasmic rarefaction, inflammation, or lipidosis.

The diagnostic performance of perfusion MRI for differentiating glioma recurrence from pseudoprogression: A meta-analysis.

PubMed

Wan, Bing; Wang, Siqi; Tu, Mengqi; Wu, Bo; Han, Ping; Xu, Haibo

2017-03-01

The purpose of this meta-analysis was to evaluate the diagnostic accuracy of perfusion magnetic resonance imaging (MRI) as a method for differentiating glioma recurrence from pseudoprogression. The PubMed, Embase, Cochrane Library, and Chinese Biomedical databases were searched comprehensively for relevant studies up to August 3, 2016 according to specific inclusion and exclusion criteria. The quality of the included studies was assessed according to the quality assessment of diagnostic accuracy studies (QUADAS-2). After performing heterogeneity and threshold effect tests, pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were calculated. Publication bias was evaluated visually by a funnel plot and quantitatively using Deek funnel plot asymmetry test. The area under the summary receiver operating characteristic curve was calculated to demonstrate the diagnostic performance of perfusion MRI. Eleven studies covering 416 patients and 418 lesions were included in this meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 0.88 (95% confidence interval [CI] 0.84-0.92), 0.77 (95% CI 0.69-0.84), 3.93 (95% CI 2.83-5.46), 0.16 (95% CI 0.11-0.22), and 27.17 (95% CI 14.96-49.35), respectively. The area under the summary receiver operating characteristic curve was 0.8899. There was no notable publication bias. Sensitivity analysis showed that the meta-analysis results were stable and credible. While perfusion MRI is not the ideal diagnostic method for differentiating glioma recurrence from pseudoprogression, it could improve diagnostic accuracy. Therefore, further research on combining perfusion MRI with other imaging modalities is warranted.

A computational framework for converting textual clinical diagnostic criteria into the quality data model.

PubMed

Hong, Na; Li, Dingcheng; Yu, Yue; Xiu, Qiongying; Liu, Hongfang; Jiang, Guoqian

2016-10-01

Constructing standard and computable clinical diagnostic criteria is an important but challenging research field in the clinical informatics community. The Quality Data Model (QDM) is emerging as a promising information model for standardizing clinical diagnostic criteria. To develop and evaluate automated methods for converting textual clinical diagnostic criteria in a structured format using QDM. We used a clinical Natural Language Processing (NLP) tool known as cTAKES to detect sentences and annotate events in diagnostic criteria. We developed a rule-based approach for assigning the QDM datatype(s) to an individual criterion, whereas we invoked a machine learning algorithm based on the Conditional Random Fields (CRFs) for annotating attributes belonging to each particular QDM datatype. We manually developed an annotated corpus as the gold standard and used standard measures (precision, recall and f-measure) for the performance evaluation. We harvested 267 individual criteria with the datatypes of Symptom and Laboratory Test from 63 textual diagnostic criteria. We manually annotated attributes and values in 142 individual Laboratory Test criteria. The average performance of our rule-based approach was 0.84 of precision, 0.86 of recall, and 0.85 of f-measure; the performance of CRFs-based classification was 0.95 of precision, 0.88 of recall and 0.91 of f-measure. We also implemented a web-based tool that automatically translates textual Laboratory Test criteria into the QDM XML template format. The results indicated that our approaches leveraging cTAKES and CRFs are effective in facilitating diagnostic criteria annotation and classification. Our NLP-based computational framework is a feasible and useful solution in developing diagnostic criteria representation and computerization. Copyright © 2016 Elsevier Inc. All rights reserved.

Cheyletiella infestation in the dog: observations on diagnostic methods and clinical signs.

PubMed

Saevik, B K; Bredal, W; Ulstein, T L

2004-10-01

The aims of this study were to evaluate the ability of diagnostic methods to detect naturally occurring Cheyletiella infestation in dogs, and to quantify and relate the number of mites and eggs present to clinical signs. Privately owned dogs with skin problems were eligible for inclusion in the study. Four diagnostic tests were performed on each dog in the following order: tape impression, hair plucking, skin scraping and vacuum cleaning. Dogs with positive test results for Cheyletiella infestation in at least one of the tests under evaluation were included in the study (n=27). The severity of pruritus and scaling was graded on a four-point fixed scale. The diagnostic findings in vacuum cleaning samples provided a semiquantitative measure of the grade of infestation. The vacuum cleaning test gave a positive test result in all dogs and was significantly more efficient than the other tests evaluated (P<0.01). The number of diagnostic findings varied considerably among the different vacuum samples. No significant relationship between the number of diagnostic findings and severity of clinical signs was detected.

Diagnosing common bile duct obstruction: comparison of image quality and diagnostic performance of three-dimensional magnetic resonance cholangiopancreatography with and without compressed sensing.

PubMed

Kwon, Heejin; Reid, Scott; Kim, Dongeun; Lee, Sangyun; Cho, Jinhan; Oh, Jongyeong

2018-01-04

This study aimed to evaluate image quality and diagnostic performance of a recently developed navigated three-dimensional magnetic resonance cholangiopancreatography (3D-MRCP) with compressed sensing (CS) based on parallel imaging (PI) and conventional 3D-MRCP with PI only in patients with abnormal bile duct dilatation. This institutional review board-approved study included 45 consecutive patients [non-malignant common bile duct lesions (n = 21) and malignant common bile duct lesions (n = 24)] who underwent MRCP of the abdomen to evaluate bile duct dilatation. All patients were imaged at 3T (MR 750, GE Healthcare, Waukesha, WI) including two kinds of 3D-MRCP using 352 × 288 matrices with and without CS based on PI. Two radiologists independently and blindly assessed randomized images. CS acceleration reduced the acquisition time on average 5 min and 6 s to a total of 2 min and 56 s. The all CS cine image quality was significantly higher than standard cine MR image for all quantitative measurements. Diagnostic accuracy for benign and malignant lesions is statistically different between standard and CS 3D-MRCP. Total image quality and diagnostic accuracy at biliary obstruction evaluation demonstrates that CS-accelerated 3D-MRCP sequences can provide superior quality of diagnostic information in 42.5% less time. This has the potential to reduce motion-related artifacts and improve diagnostic efficacy.

Fully Automated Quantification of the Striatal Uptake Ratio of [99mTc]-TRODAT with SPECT Imaging: Evaluation of the Diagnostic Performance in Parkinson's Disease and the Temporal Regression of Striatal Tracer Uptake

PubMed Central

Fang, Yu-Hua Dean; Chiu, Shao-Chieh; Lu, Chin-Song; Weng, Yi-Hsin

2015-01-01

Purpose. We aimed at improving the existing methods for the fully automatic quantification of striatal uptake of [99mTc]-TRODAT with SPECT imaging. Procedures. A normal [99mTc]-TRODAT template was first formed based on 28 healthy controls. Images from PD patients (n = 365) and nPD subjects (28 healthy controls and 33 essential tremor patients) were spatially normalized to the normal template. We performed an inverse transform on the predefined striatal and reference volumes of interest (VOIs) and applied the transformed VOIs to the original image data to calculate the striatal-to-reference ratio (SRR). The diagnostic performance of the SRR was determined through receiver operating characteristic (ROC) analysis. Results. The SRR measured with our new and automatic method demonstrated excellent diagnostic performance with 92% sensitivity, 90% specificity, 92% accuracy, and an area under the curve (AUC) of 0.94. For the evaluation of the mean SRR and the clinical duration, a quadratic function fit the data with R 2 = 0.84. Conclusions. We developed and validated a fully automatic method for the quantification of the SRR in a large study sample. This method has an excellent diagnostic performance and exhibits a strong correlation between the mean SRR and the clinical duration in PD patients. PMID:26366413

Fully Automated Quantification of the Striatal Uptake Ratio of [(99m)Tc]-TRODAT with SPECT Imaging: Evaluation of the Diagnostic Performance in Parkinson's Disease and the Temporal Regression of Striatal Tracer Uptake.

PubMed

Fang, Yu-Hua Dean; Chiu, Shao-Chieh; Lu, Chin-Song; Yen, Tzu-Chen; Weng, Yi-Hsin

2015-01-01

We aimed at improving the existing methods for the fully automatic quantification of striatal uptake of [(99m)Tc]-TRODAT with SPECT imaging. A normal [(99m)Tc]-TRODAT template was first formed based on 28 healthy controls. Images from PD patients (n = 365) and nPD subjects (28 healthy controls and 33 essential tremor patients) were spatially normalized to the normal template. We performed an inverse transform on the predefined striatal and reference volumes of interest (VOIs) and applied the transformed VOIs to the original image data to calculate the striatal-to-reference ratio (SRR). The diagnostic performance of the SRR was determined through receiver operating characteristic (ROC) analysis. The SRR measured with our new and automatic method demonstrated excellent diagnostic performance with 92% sensitivity, 90% specificity, 92% accuracy, and an area under the curve (AUC) of 0.94. For the evaluation of the mean SRR and the clinical duration, a quadratic function fit the data with R (2) = 0.84. We developed and validated a fully automatic method for the quantification of the SRR in a large study sample. This method has an excellent diagnostic performance and exhibits a strong correlation between the mean SRR and the clinical duration in PD patients.

Preliminary Results of Acoustic Radiation Force Impulse Imaging by Combined Qualitative and Quantitative Analyses for Evaluation of Breast Lesions.

PubMed

Wang, Lin; Wan, Cai-Feng; Du, Jing; Li, Feng-Hua

2018-04-15

The purpose of this study was to evaluate the application of a new elastographic technique, acoustic radiation force impulse (ARFI) imaging, and its diagnostic performance for characterizing breast lesions. One hundred consecutive female patients with 126 breast lesions were enrolled in our study. After routine breast ultrasound examinations, the patients underwent ARFI elasticity imaging. Virtual Touch tissue imaging (VTI) and Virtual Touch tissue quantification (Siemens Medical Solutions, Mountain View, CA) were used to qualitatively and quantitatively analyze the elasticity and hardness of tumors. A receiver operating characteristic curve analysis was performed to evaluate the diagnostic performance of ARFI for discrimination between benign and malignant breast lesions. Pathologic analysis revealed 40 lesions in the malignant group and 86 lesions in the benign group. Different VTI patterns were observed in benign and malignant breast lesions. Eighty lesions (93.0%) of benign group had pattern 1, 2, or 3, whereas all pattern 4b lesions (n = 20 [50.0%]) were malignant. Regarding the quantitative analysis, the mean VTI-to-B-mode area ratio, internal shear wave velocity, and marginal shear wave velocity of benign lesions were statistically significantly lower than those of malignant lesions (all P < .001). The cutoff point for a scoring system constructed to evaluate the diagnostic performance of ARFI was estimated to be between 3 and 4 points for malignancy, with sensitivity of 77.5%, specificity of 96.5%, accuracy of 90.5%, and an area under the curve of 0.933. The application of ARFI technology has shown promising results by noninvasively providing substantial complementary information and could potentially serve as an effective diagnostic tool for differentiation between benign and malignant breast lesions. © 2018 by the American Institute of Ultrasound in Medicine.

Routine Ultrasound and Limited Computed Tomography for the Diagnosis of Acute Appendicitis

PubMed Central

Wiersma, Fraukje; Bakker, Rutger F. R.; Merkus, Jos W. S.; Breslau, Paul J.; Hamming, Jaap F.

2010-01-01

Background Acute appendicitis continues to be a challenging diagnosis. Preoperative radiological imaging using ultrasound (US) or computed tomography (CT) has gained popularity as it may offer a more accurate diagnosis than classic clinical evaluation. The optimal implementation of these diagnostic modalities has yet to be established. The aim of the present study was to investigate a diagnostic pathway that uses routine US, limited CT, and clinical re-evaluation for patients with acute appendicitis. Methods A prospective analysis was performed of all patients presenting with acute abdominal pain at the emergency department from June 2005 until July 2006 using a structured diagnosis and management flowchart. Daily practice was mimicked, while ensuring a valid assessment of clinical and radiological diagnostic accuracies and the effect they had on patient management. Results A total of 802 patients were included in this analysis. Additional radiological imaging was performed in 96.3% of patients with suspected appendicitis (n = 164). Use of CT was kept to a minimum (17.9%), with a US:CT ratio of approximately 6:1. Positive and negative predictive values for the clinical diagnosis of appendicitis were 63 and 98%, respectively; for US 94 and 97%, respectively; and for CT 100 and 100%, respectively. The negative appendicitis rate was 3.3%, the perforation rate was 23.5%, and the missed perforated appendicitis rate was 3.4%. No (diagnostic) laparoscopies were performed. Conclusions A diagnostic pathway using routine US, limited CT, and clinical re-evaluation for patients with acute abdominal pain can provide excellent results for the diagnosis and treatment of appendicitis. PMID:20582544

Applications of Diagnostic Classification Models: A Literature Review and Critical Commentary

ERIC Educational Resources Information Center

Sessoms, John; Henson, Robert A.

2018-01-01

Diagnostic classification models (DCMs) classify examinees based on the skills they have mastered given their test performance. This classification enables targeted feedback that can inform remedial instruction. Unfortunately, applications of DCMs have been criticized (e.g., no validity support). Generally, these evaluations have been brief and…

Software Tools to Support the Assessment of System Health

NASA Technical Reports Server (NTRS)

Melcher, Kevin J.

2013-01-01

This presentation provides an overview of three software tools that were developed by the NASA Glenn Research Center to support the assessment of system health: the Propulsion Diagnostic Method Evaluation Strategy (ProDIMES), the Systematic Sensor Selection Strategy (S4), and the Extended Testability Analysis (ETA) tool. Originally developed to support specific NASA projects in aeronautics and space, these software tools are currently available to U.S. citizens through the NASA Glenn Software Catalog. The ProDiMES software tool was developed to support a uniform comparison of propulsion gas path diagnostic methods. Methods published in the open literature are typically applied to dissimilar platforms with different levels of complexity. They often address different diagnostic problems and use inconsistent metrics for evaluating performance. As a result, it is difficult to perform a one ]to ]one comparison of the various diagnostic methods. ProDIMES solves this problem by serving as a theme problem to aid in propulsion gas path diagnostic technology development and evaluation. The overall goal is to provide a tool that will serve as an industry standard, and will truly facilitate the development and evaluation of significant Engine Health Management (EHM) capabilities. ProDiMES has been developed under a collaborative project of The Technical Cooperation Program (TTCP) based on feedback provided by individuals within the aircraft engine health management community. The S4 software tool provides a framework that supports the optimal selection of sensors for health management assessments. S4 is structured to accommodate user ]defined applications, diagnostic systems, search techniques, and system requirements/constraints. One or more sensor suites that maximize this performance while meeting other user ]defined system requirements that are presumed to exist. S4 provides a systematic approach for evaluating combinations of sensors to determine the set or sets of sensors that optimally meet the performance goals and the constraints. It identifies optimal sensor suite solutions by utilizing a merit (i.e., cost) function with one of several available optimization approaches. As part of its analysis, S4 can expose fault conditions that are difficult to diagnose due to an incomplete diagnostic philosophy and/or a lack of sensors. S4 was originally developed and applied to liquid rocket engines. It was subsequently used to study the optimized selection of sensors for a simulation ]based aircraft engine diagnostic system. The ETA Tool is a software ]based analysis tool that augments the testability analysis and reporting capabilities of a commercial ]off ]the ]shelf (COTS) package. An initial diagnostic assessment is performed by the COTS software using a user ]developed, qualitative, directed ]graph model of the system being analyzed. The ETA Tool accesses system design information captured within the model and the associated testability analysis output to create a series of six reports for various system engineering needs. These reports are highlighted in the presentation. The ETA Tool was developed by NASA to support the verification of fault management requirements early in the Launch Vehicle process. Due to their early development during the design process, the TEAMS ]based diagnostic model and the ETA Tool were able to positively influence the system design by highlighting gaps in failure detection, fault isolation, and failure recovery.

Stationary intraoral tomosynthesis for dental imaging

NASA Astrophysics Data System (ADS)

Inscoe, Christina R.; Wu, Gongting; Soulioti, Danai E.; Platin, Enrique; Mol, Andre; Gaalaas, Laurence R.; Anderson, Michael R.; Tucker, Andrew W.; Boyce, Sarah; Shan, Jing; Gonzales, Brian; Lu, Jianping; Zhou, Otto

2017-03-01

Despite recent advances in dental radiography, the diagnostic accuracies for some of the most common dental diseases have not improved significantly, and in some cases remain low. Intraoral x-ray is the most commonly used x-ray diagnostic tool in dental clinics. It however suffers from the typical limitations of a 2D imaging modality including structure overlap. Cone-beam computed tomography (CBCT) uses high radiation dose and suffers from image artifacts and relatively low resolution. The purpose of this study is to investigate the feasibility of developing a stationary intraoral tomosynthesis (s-IOT) using spatially distributed carbon nanotube (CNT) x-ray array technology, and to evaluate its diagnostic accuracy compared to conventional 2D intraoral x-ray. A bench-top s-IOT device was constructed using a linear CNT based X-ray source array and a digital intraoral detector. Image reconstruction was performed using an iterative reconstruction algorithm. Studies were performed to optimize the imaging configuration. For evaluation of s-IOT's diagnostic accuracy, images of a dental quality assurance phantom, and extracted human tooth specimens were acquired. Results show s-IOT increases the diagnostic sensitivity for caries compared to intraoral x-ray at a comparable dose level.

Towards improving diagnosis of memory loss in general practice: TIMeLi diagnostic test accuracy study protocol.

PubMed

Creavin, Sam T; Cullum, Sarah J; Haworth, Judy; Wye, Lesley; Bayer, Antony; Fish, Mark; Purdy, Sarah; Ben-Shlomo, Yoav

2016-07-19

People with cognitive problems, and their families, report distress and uncertainty whilst undergoing evaluation for dementia and perceive that traditional diagnostic evaluation in secondary care is insufficiently patient centred. The James Lind Alliance has prioritised research to investigate the role of primary care in supporting a more effective diagnostic pathway, and the topic is also of interest to health commissioners. However, there are very few studies that investigate the accuracy of diagnostic tests for dementia in primary care. We will conduct a prospective diagnostic test accuracy study to evaluate the accuracy of a range of simple tests for diagnosing all-cause-dementia in symptomatic people aged over 70 years who have consulted with their general practitioner (GP). We will invite eligible people to attend a research clinic where they will undergo a range of index tests that a GP could perform in the surgery and also be assessed by a specialist in memory disorders at the same appointment. Participating GPs will request neuroimaging and blood tests and otherwise manage patients in line with their usual clinical practice. The reference standard will be the consensus judgement of three experts (neurologist, psychiatrist and geriatrician) based on information from the specialist assessment, GP records and investigations, but not including items in the index test battery. The target condition will be all-cause dementia but we will also investigate diagnostic accuracy for sub-types where possible. We will use qualitative interviews with patients and focus groups with clinicians to help us understand the acceptability and feasibility of diagnosing dementia in primary care using the tests that we are investigating. Our results will help clinicians decide on which tests to perform in someone where there is concern about possible dementia and inform commissioning of diagnostic pathways.

The utility of ultrasound superb microvascular imaging for evaluation of breast tumour vascularity: comparison with colour and power Doppler imaging regarding diagnostic performance.

PubMed

Park, A Y; Seo, B K; Woo, O H; Jung, K S; Cho, K R; Park, E K; Cha, S H; Cha, J

2018-03-01

To investigate the utility of superb microvascular imaging (SMI) for evaluating the vascularity of breast masses in comparison with colour or power Doppler ultrasound (US) and the effect on diagnostic performance. A total of 191 biopsy-proven masses (99 benign and 92 malignant) in 166 women with greyscale, colour Doppler, power Doppler, and SMI images were enrolled in this retrospective study. Three radiologists analysed the vascular images using a three-factor scoring system to evaluate the number, morphology, and distribution of tumour vessels. They assessed the Breast Imaging-Reporting and Data System categories for greyscale US alone and combinations of greyscale US and each type of vascular US. The Kruskal-Wallis test was performed and the area under the receiver-operating characteristic curve (AUC) measured. On SMI, vascular scores were compared between benign and malignant masses and the optimal cut-off value for the overall score was determined. SMI showed higher vascular scores than colour or power Doppler US and malignant masses had higher scores than benign masses (p<0.001). The diagnostic performance of the combination of greyscale US and SMI was higher than those of greyscale US alone and greyscale and colour or power Doppler US (AUC, 0.815 versus 0.774, 0.789, 0.791; p<0.001). The optimal cut-off value of the overall vascular score was 5 with a sensitivity of 82.3% and a specificity of 65.3% (AUC, 0.808). SMI is superior to colour or power Doppler US for characterising the vascularity in breast masses and improving diagnostic performance. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Diagnostic performance of neck circumference to identify overweight and obesity as defined by body mass index in children and adolescents: systematic review and meta-analysis.

PubMed

Ma, Chunming; Wang, Rui; Liu, Yue; Lu, Qiang; Liu, Xiaoli; Yin, Fuzai

2017-05-01

The neck circumference (NC) has been shown to be an accurate index for screening overweight and obesity in children and adolescents. To perform a meta-analysis to assess the performance of NC for the assessment of overweight and obesity. Data sources were PubMed and EMBASE up to March 2016. Studies providing measures of diagnostic performance of NC and using body mass index as reference standard were included. Six eligible studies that evaluated 11 214 children and adolescents aged 6-18 years were included in the meta-analysis. NC showed pooled sensitivity to detect high body mass index of 0.780 (95% confidence interval [CI] = 0.765-0.794), specificity of 0.746 (95% CI =  0.736-0.756) and a diagnostic odds ratio of 17.343 (95% CI =  8.743-34.405). The NC had moderate diagnostic accuracy for identifying overweight and obesity in children and adolescents.

Sublingual Nitroglycerin Administration in Coronary Computed Tomography Angiography: a Systematic Review.

PubMed

Takx, Richard A P; Suchá, Dominika; Park, Jakob; Leiner, Tim; Hoffmann, Udo

2015-12-01

To systematically investigate the literature for the influence of sublingual nitroglycerin administration on coronary diameter, the number of evaluable segments, image quality, heart rate and blood pressure, and diagnostic accuracy of coronary computed tomography (CT) angiography. A systematic search was performed in PubMed, EMBASE and Web of Science. The studies were evaluated for the effect of sublingual nitroglycerin on coronary artery diameter, evaluable segments, objective and subjective image quality, systemic physiological effects and diagnostic accuracy. Due to the heterogeneous reporting of outcome measures, a narrative synthesis was applied. Of the 217 studies identified, nine met the inclusion criteria: seven reported on the effect of nitroglycerin on coronary artery diameter, six on evaluable segments, four on image quality, five on systemic physiological effects and two on diagnostic accuracy. Sublingual nitroglycerin administration resulted in an improved evaluation of more coronary segments, in particular, in smaller coronary branches, better image quality and improved diagnostic accuracy. Side effects were mild and were alleviated without medical intervention. Sublingual nitroglycerin improves the coronary diameter, the number of assessable segments, image quality and diagnostic accuracy of coronary CT angiography without major side effects or systemic physiological changes. • Sublingual nitroglycerin administration results in significant coronary artery dilatation. • Nitroglycerin increases the number of evaluable coronary branches. • Image quality is improved the most in smaller coronary branches. • Nitroglycerin increases the diagnostic accuracy of coronary CT angiography. • Most side effects are mild and do not require medical intervention.

Interpretation of bedside chest X-rays in the ICU: is the radiologist still needed?

PubMed

Martini, Katharina; Ganter, Christoph; Maggiorini, Marco; Winklehner, Anna; Leupi-Skibinski, Katarzyna E; Frauenfelder, Thomas; Nguyen-Kim, Thi Dan Linh

2015-01-01

To compare diagnostic accuracy of intensivists to radiologists in reading bedside chest X-rays. In a retrospective trial, 33 bedside chest X-rays were evaluated by five radiologists and five intensivists with different experience. Images were evaluated for devices and lung pathologies. Interobserver agreement and diagnostic accuracy were calculated. Computed tomography served as reference standard. Seniors had higher diagnostic accuracy than residents (mean-ExpB(Senior)=1.456; mean-ExpB(Resident)=1.635). Interobserver agreement for installations was more homogenously distributed between radiologists compared to intensivists (ExpB(Rad)=1.204-1.672; ExpB(Int)=1.005-2.368). Seniors had comparable diagnostic accuracy. No significant difference in diagnostic performance was seen between seniors of both disciplines, whereas the resident intensivists might still benefit from an interdisciplinary dialogue. Copyright © 2015 Elsevier Inc. All rights reserved.

Health Technology Assessment for Molecular Diagnostics: Practices, Challenges, and Recommendations from the Medical Devices and Diagnostics Special Interest Group.

PubMed

Garfield, Susan; Polisena, Julie; S Spinner, Daryl; Postulka, Anne; Y Lu, Christine; Tiwana, Simrandeep K; Faulkner, Eric; Poulios, Nick; Zah, Vladimir; Longacre, Michael

2016-01-01

Health technology assessments (HTAs) are increasingly used to inform coverage, access, and utilization of medical technologies including molecular diagnostics (MDx). Although MDx are used to screen patients and inform disease management and treatment decisions, there is no uniform approach to their evaluation by HTA organizations. The International Society for Pharmacoeconomics and Outcomes Research Devices and Diagnostics Special Interest Group reviewed diagnostic-specific HTA programs and identified elements representing common and best practices. MDx-specific HTA programs in Europe, Australia, and North America were characterized by methodology, evaluation framework, and impact. Published MDx HTAs were reviewed, and five representative case studies of test evaluations were developed: United Kingdom (National Institute for Health and Care Excellence's Diagnostics Assessment Programme, epidermal growth factor receptor tyrosine kinase mutation), United States (Palmetto's Molecular Diagnostic Services Program, OncotypeDx prostate cancer test), Germany (Institute for Quality and Efficiency in Healthcare, human papillomavirus testing), Australia (Medical Services Advisory Committee, anaplastic lymphoma kinase testing for non-small cell lung cancer), and Canada (Canadian Agency for Drugs and Technologies in Health, Rapid Response: Non-invasive Prenatal Testing). Overall, the few HTA programs that have MDx-specific methods do not provide clear parameters of acceptability related to clinical and analytic performance, clinical utility, and economic impact. The case studies highlight similarities and differences in evaluation approaches across HTAs in the performance metrics used (analytic and clinical validity, clinical utility), evidence requirements, and how value is measured. Not all HTAs are directly linked to reimbursement outcomes. To improve MDx HTAs, organizations should provide greater transparency, better communication and collaboration between industry and HTA stakeholders, clearer links between HTA and funding decisions, explicit recognition of and rationale for differential approaches to laboratory-developed versus regulatory-approved test, and clear evidence requirements. Copyright © 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

A qualitative investigation into the usefulness and impact of the performance intervention zone system used in the diagnostic assessment of internationally educated massage therapists.

PubMed

Finch, Paul; Baskwill, Amanda

2011-04-01

Previous work (Finch, 2008) reported on the development and implementation of a safety oriented system of performance intervention zones (PIZ), which was used in the assessment of internationally educated massage therapists. The study reported in this paper explores the usefulness and impact of the system as experienced by the evaluators involved in the diagnostic assessment. This exploratory research was of a qualitative design in which data were collected during a series of individual semi-structured interviews with evaluators who used the performance intervention zone system during the diagnostic assessment of internationally educated massage therapists in Ontario. After obtaining informed consent, interviews were taped, transcribed and analyzed, resulting in identification of a number of themes and recommendations regarding future use and development of the system. Analysis revealed four themes within the data. These were that the performance intervention zone system 1) enhanced the confidence of examiners in their ability to conduct the comprehensive clinical examination effectively, 2) assisted and improved examiner decision making during the examination, 3) was a useful aid to communication regarding candidate performance, and 4) could be improved by clarifying the nature of intervention and implementing more extensive examiner training prior to the examination. The performance intervention zone system was found to be useful in orienting examiners to the evaluation process, in supporting decision making during the comprehensive clinical evaluation and as an aid to communication in the post-examination review of candidate performance. The system could be improved through implementation of a pre-examination workshop focused on use of the PIZ and by delineation of levels of examiner intervention during the examination. Copyright © 2010 Elsevier Ltd. All rights reserved.

Combined diagnostic performance of coronary computed tomography angiography and computed tomography derived fractional flow reserve for the evaluation of myocardial ischemia: A meta-analysis.

PubMed

Tan, Xiao Wei; Zheng, Qishi; Shi, Luming; Gao, Fei; Allen, John Carson; Coenen, Adriaan; Baumann, Stefan; Schoepf, U Joseph; Kassab, Ghassan S; Lim, Soo Teik; Wong, Aaron Sung Lung; Tan, Jack Wei Chieh; Yeo, Khung Keong; Chin, Chee Tang; Ho, Kay Woon; Tan, Swee Yaw; Chua, Terrance Siang Jin; Chan, Edwin Shih Yen; Tan, Ru San; Zhong, Liang

2017-06-01

To evaluate the combined diagnostic accuracy of coronary computed tomography angiography (CCTA) and computed tomography derived fractional flow reserve (FFRct) in patients with suspected or known coronary artery disease (CAD). PubMed, The Cochrane library, Embase and OpenGray were searched to identify studies comparing diagnostic accuracy of CCTA and FFRct. Diagnostic test measurements of FFRct were either extracted directly from the published papers or calculated from provided information. Bivariate models were conducted to synthesize the diagnostic performance of combined CCTA and FFRct at both "per-vessel" and "per-patient" levels. 7 articles were included for analysis. The combined diagnostic outcomes from "both positive" strategy, i.e. a subject was considered as "positive" only when both CCTA and FFRct were "positive", demonstrated relative high specificity (per-vessel: 0.91; per-patient: 0.81), high positive likelihood ratio (LR+, per-vessel: 7.93; per-patient: 4.26), high negative likelihood ratio (LR-, per-vessel: 0.30; per patient: 0.24) and high accuracy (per-vessel: 0.91; per-patient: 0.81) while "either positive" strategy, i.e. a subject was considered as "positive" when either CCTA or FFRct was "positive", demonstrated relative high sensitivity (per-vessel: 0.97; per-patient: 0.98), low LR+ (per-vessel: 1.50; per-patient: 1.17), low LR- (per-vessel: 0.07; per-patient: 0.09) and low accuracy (per-vessel: 0.57; per-patient: 0.54). "Both positive" strategy showed better diagnostic performance to rule in patients with non-significant stenosis compared to "either positive" strategy, as it efficiently reduces the proportion of testing false positive subjects. Copyright © 2017 Elsevier B.V. All rights reserved.

Diagnostic criteria for hepatocellular carcinoma ⩽3 cm with hepatocyte-specific contrast-enhanced magnetic resonance imaging.

PubMed

Choi, Sang Hyun; Byun, Jae Ho; Lim, Young-Suk; Yu, Eunsil; Lee, So Jung; Kim, So Yeon; Won, Hyung Jin; Shin, Yong Moon; Kim, Pyo Nyun

2016-05-01

Current diagnostic imaging criteria for hepatocellular carcinoma (HCC) are dedicated to imaging with nonspecific extracellular contrast agents. This study aimed to evaluate diagnostic criteria for HCC ⩽3 cm on magnetic resonance imaging (MRI) with a hepatocyte-specific contrast agent through an inception cohort study. Of 291 patients with chronic liver disease and new nodules of 1-3 cm in diameter at surveillance ultrasonography, 295 solid nodules (194 HCCs, 98 benign nodules, and three other malignancies) in 198 patients with a confirmed final diagnosis or ⩾24 months follow-up were evaluated on gadoxetic acid-enhanced MRI. Through univariate and multivariate logistic regression analyses, various diagnostic criteria were developed by combining significant MRI findings for diagnosing HCC. The diagnostic performance of each criterion was compared with that of the European Association for the Study of the Liver (EASL) criteria. Four MRI findings (arterial-phase hyperintensity, transitional-phase hypointensity, hepatobiliary-phase hypointensity, and rim enhancement) were independently significant for diagnosis of HCC ⩽3 cm. For whole nodules, EASL criteria showed the best performance for diagnosing HCC (sensitivity, 83.5%; specificity, 81.2%). For nodules ⩽2 cm in diameter, a new criterion (arterial-phase hyperintensity and hepatobiliary-phase hypointensity) showed a significantly higher sensitivity than that of the EASL criteria (83.0% vs. 74.5%, p=0.008), without a significantly different specificity (76.7% vs. 81.1%, p=0.125). EASL criteria exhibit the best diagnostic performance for HCC ⩽3 cm on hepatocyte-specific contrast-enhanced MRI. A newly identified criterion (arterial-phase hyperintensity and hepatobiliary-phase hypointensity) may increase the diagnostic sensitivity of small (⩽2 cm) HCC. Copyright © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

C-Arm Cone-Beam CT-Guided Transthoracic Lung Core Needle Biopsy as a Standard Diagnostic Tool

PubMed Central

Jaconi, Marta; Pagni, Fabio; Vacirca, Francesco; Leni, Davide; Corso, Rocco; Cortinovis, Diego; Bidoli, Paolo; Bono, Francesca; Cuttin, Maria S.; Valente, Maria G.; Pesci, Alberto; Bedini, Vittorio A.; Leone, Biagio E.

2015-01-01

Abstract C-arm cone-beam computed tomography (CT)-guided transthoracic lung core needle biopsy (CNB) is a safe and accurate procedure for the evaluation of patients with pulmonary nodules. This article will focus on the clinical features related to CNB in terms of diagnostic performance and complication rate. Moreover, the concept of categorizing pathological diagnosis into 4 categories, which could be used for clinical management, follow-up, and quality assurance is also introduced. We retrospectively collected data regarding 375 C-arm cone-beam CT-guided CNBs from January 2010 and June 2014. Clinical and radiological variables were evaluated in terms of success or failure rate. Pathological reports were inserted in 4 homogenous groups (nondiagnostic-L1, benign-L2, malignant not otherwise specified-L3, and malignant with specific histotype-L4), defining for each category a hierarchy of suggested actions. The sensitivity, specificity, and positive and negative predictive value and accuracy for patients subjected to CNBs were of 96.8%, 100%, 100%, 100%, and 97.2%, respectively. Roughly 75% of our samples were diagnosed as malignant, with 60% lung adenocarcinoma diagnoses. Molecular analyses were performed on 85 malignant samples to verify applicability of targeted therapy. The rate of “nondiagnostic” samples was 12%. C-arm cone-beam CT-guided transthoracic lung CNB can represent the gold standard for the diagnostic evaluation of pulmonary nodules. A clinical and pathological multidisciplinary evaluation of CNBs was needed in terms of integration of radiological, histological, and oncological data. This approach provided exceptional performances in terms of specificity, positive and negative predictive values; sensitivity in our series was lower compared with other large studies, probably due to the application of strong criteria of adequacy for CNBs (L1 class rate). The satisfactory rate of collected material was evaluated not only in terms of merely diagnostic performances but also for predictive results by molecular analysis. PMID:25816042

C-arm cone-beam CT-guided transthoracic lung core needle biopsy as a standard diagnostic tool: an observational study.

PubMed

Jaconi, Marta; Pagni, Fabio; Vacirca, Francesco; Leni, Davide; Corso, Rocco; Cortinovis, Diego; Bidoli, Paolo; Bono, Francesca; Cuttin, Maria S; Valente, Maria G; Pesci, Alberto; Bedini, Vittorio A; Leone, Biagio E

2015-03-01

C-arm cone-beam computed tomography (CT)-guided transthoracic lung core needle biopsy (CNB) is a safe and accurate procedure for the evaluation of patients with pulmonary nodules. This article will focus on the clinical features related to CNB in terms of diagnostic performance and complication rate. Moreover, the concept of categorizing pathological diagnosis into 4 categories, which could be used for clinical management, follow-up, and quality assurance is also introduced. We retrospectively collected data regarding 375 C-arm cone-beam CT-guided CNBs from January 2010 and June 2014. Clinical and radiological variables were evaluated in terms of success or failure rate. Pathological reports were inserted in 4 homogenous groups (nondiagnostic--L1, benign--L2, malignant not otherwise specified--L3, and malignant with specific histotype--L4), defining for each category a hierarchy of suggested actions. The sensitivity, specificity, and positive and negative predictive value and accuracy for patients subjected to CNBs were of 96.8%, 100%, 100%, 100%, and 97.2%, respectively. Roughly 75% of our samples were diagnosed as malignant, with 60% lung adenocarcinoma diagnoses. Molecular analyses were performed on 85 malignant samples to verify applicability of targeted therapy. The rate of "nondiagnostic" samples was 12%. C-arm cone-beam CT-guided transthoracic lung CNB can represent the gold standard for the diagnostic evaluation of pulmonary nodules. A clinical and pathological multidisciplinary evaluation of CNBs was needed in terms of integration of radiological, histological, and oncological data. This approach provided exceptional performances in terms of specificity, positive and negative predictive values; sensitivity in our series was lower compared with other large studies, probably due to the application of strong criteria of adequacy for CNBs (L1 class rate). The satisfactory rate of collected material was evaluated not only in terms of merely diagnostic performances but also for predictive results by molecular analysis.

Variable Use of Disaccharidase Assays When Evaluating Abdominal Pain

PubMed Central

Oloyede, Hannah

2018-01-01

Background and Aims: Patients with a disaccharidase deficiency typically present with abdominal discomfort and often with diarrhea. However, disaccharidase deficiency is often overlooked as a cause of these complaints. Therefore, we sought to determine the prevalence of lactase and sucrase deficiencies in a pediatric population undergoing diagnostic esophagogastroduodenoscopy (EGD) and to describe disaccharidase testing practices among pediatric gastroenterologists. Methods: Endoscopic records from patients undergoing diagnostic EGD and disaccharidase analysis (DA) were retrospectively reviewed. Diagnostic EGDs performed over a 5-year period (2010 through 2014) at a freestanding endoscopy center serving 13 pediatric gastroenterologists were assessed. Demographic and clinical data on patients were collected and grouped; patients with primary sucrase-isomaltase deficiency (SID) were the main focus. The data were stratified by the physician performing the procedures. Results: Over the 5-year study period, 5368 EGDs were performed, with abdominal pain as the primary indication in 3235 cases (60.2%). DAs were performed on 963 patients (17.9% of the total cohort; 29.8% of those with abdominal pain). Lactase deficiencies, sucrase deficiencies, and primary SID were found in 44.7%, 7.6%, and 3.5% of DAs, respectively. The number of DAs performed varied widely among physicians, ranging from 1.6% to 64.5% of EGDs evaluating patients with abdominal pain. Univariate regression analysis revealed significant correlations between the number of DAs performed and the number of SID and lactase deficiencies found (P<.001 for both). Conclusion: Rates of DAs vary widely among pediatric gastroenterologists performing diagnostic EGDs in children with abdominal pain. Physician education and clinical practice guidelines regarding the use of DAs are warranted. PMID:29491758

Influenza detection and prediction algorithms: comparative accuracy trial in Östergötland county, Sweden, 2008-2012.

PubMed

Spreco, A; Eriksson, O; Dahlström, Ö; Timpka, T

2017-07-01

Methods for the detection of influenza epidemics and prediction of their progress have seldom been comparatively evaluated using prospective designs. This study aimed to perform a prospective comparative trial of algorithms for the detection and prediction of increased local influenza activity. Data on clinical influenza diagnoses recorded by physicians and syndromic data from a telenursing service were used. Five detection and three prediction algorithms previously evaluated in public health settings were calibrated and then evaluated over 3 years. When applied on diagnostic data, only detection using the Serfling regression method and prediction using the non-adaptive log-linear regression method showed acceptable performances during winter influenza seasons. For the syndromic data, none of the detection algorithms displayed a satisfactory performance, while non-adaptive log-linear regression was the best performing prediction method. We conclude that evidence was found for that available algorithms for influenza detection and prediction display satisfactory performance when applied on local diagnostic data during winter influenza seasons. When applied on local syndromic data, the evaluated algorithms did not display consistent performance. Further evaluations and research on combination of methods of these types in public health information infrastructures for 'nowcasting' (integrated detection and prediction) of influenza activity are warranted.

Alpha1 LASSO data bundles Lamont, OK

DOE Data Explorer

Gustafson, William Jr; Vogelmann, Andrew; Endo, Satoshi; Toto, Tami; Xiao, Heng; Li, Zhijin; Cheng, Xiaoping; Krishna, Bhargavi (ORCID:000000018828528X)

2016-08-03

A data bundle is a unified package consisting of LASSO LES input and output, observations, evaluation diagnostics, and model skill scores. LES input includes model configuration information and forcing data. LES output includes profile statistics and full domain fields of cloud and environmental variables. Model evaluation data consists of LES output and ARM observations co-registered on the same grid and sampling frequency. Model performance is quantified by skill scores and diagnostics in terms of cloud and environmental variables.

Diagnostic value of commercially available shear-wave elastography for breast cancers: integration into BI-RADS classification with subcategories of category 4.

PubMed

Youk, Ji Hyun; Gweon, Hye Mi; Son, Eun Ju; Han, Kyung Hwa; Kim, Jeong-Ah

2013-10-01

To evaluate the diagnostic performance of shear-wave elastography (SWE) for breast cancer and to determine whether the integration of SWE into BI-RADS with subcategories of category 4 improves the diagnostic performance. A total of 389 breast masses (malignant 120, benign 269) in 324 women who underwent SWE before ultrasound-guided core biopsy or surgery were included. The qualitative SWE feature was assessed using a four-colour overlay pattern. Quantitative elasticity values including the lesion-to-fat elasticity ratio (Eratio) were measured. Diagnostic performance of B-mode ultrasound, SWE, or their combined studies was compared using the area under the ROC curve (AUC). AUC of Eratio (0.952) was the highest among elasticity values (mean, maximum, and minimum elasticity, 0.949, 0.939, and 0.928; P = 0.04) and AUC of colour pattern was 0.947. AUC of combined studies was significantly higher than for a single study (P < 0.0001). When adding SWE to category 4 lesions, lesions were dichotomised according to % of malignancy: 2.1 % vs. 43.2 % (category 4a) and 0 % vs. 100 % (category 4b) for Eratio and 2.4 % vs. 25.8 % (category 4a) for colour pattern (P < 0.05). Shear-wave elastography showed a good diagnostic performance. Adding SWE features to BI-RADS improved the diagnostic performance and may be helpful to stratify category 4 lesions. • Quantitative and qualitative shear-wave elastography provides further diagnostic information during breast ultrasound. • The elasticity ratio (E ratio ) showed the best diagnostic performance in SWE. • E ratio and four-colour overlay pattern significantly differed between benign and malignant lesions. • SWE features allowed further stratification of BI-RADS category 4 lesions.

Development, Evaluation, and Integration of a Quantitative Reverse-Transcription Polymerase Chain Reaction Diagnostic Test for Ebola Virus on a Molecular Diagnostics Platform

PubMed Central

Cnops, Lieselotte; Van den Eede, Peter; Pettitt, James; Heyndrickx, Leo; De Smet, Birgit; Coppens, Sandra; Andries, Ilse; Pattery, Theresa; Van Hove, Luc; Meersseman, Geert; Van Den Herrewegen, Sari; Vergauwe, Nicolas; Thijs, Rein; Jahrling, Peter B.; Nauwelaers, David; Ariën, Kevin K.

2016-01-01

Background. The 2013–2016 Ebola epidemic in West Africa resulted in accelerated development of rapid diagnostic tests for emergency outbreak preparedness. We describe the development and evaluation of the Idylla™ prototype Ebola virus test, a fully automated sample-to-result molecular diagnostic test for rapid detection of Zaire ebolavirus (EBOV) and Sudan ebolavirus (SUDV). Methods. The Idylla™ prototype Ebola virus test can simultaneously detect EBOV and SUDV in 200 µL of whole blood. The sample is directly added to a disposable cartridge containing all reagents for sample preparation, RNA extraction, and amplification by reverse-transcription polymerase chain reaction analysis. The performance was evaluated with a variety of sample types, including synthetic constructs and whole blood samples from healthy volunteers spiked with viral RNA, inactivated virus, and infectious virus. Results. The 95% limits of detection for EBOV and SUDV were 465 plaque-forming units (PFU)/mL (1010 copies/mL) and 324 PFU/mL (8204 copies/mL), respectively. In silico and in vitro analyses demonstrated 100% correct reactivity for EBOV and SUDV and no cross-reactivity with relevant pathogens. The diagnostic sensitivity was 97.4% (for EBOV) and 91.7% (for SUDV), the specificity was 100%, and the diagnostic accuracy was 95.9%. Conclusions. The Idylla™ prototype Ebola virus test is a fast, safe, easy-to-use, and near-patient test that meets the performance criteria to detect EBOV in patients with suspected Ebola. PMID:27247341

Comparison of diagnostic performances among bronchoscopic sampling techniques in the diagnosis of peripheral pulmonary lesions.

PubMed

Boonsarngsuk, Viboon; Kanoksil, Wasana; Laungdamerongchai, Sarangrat

2015-04-01

There are many sampling techniques dedicated to radial endobronchial ultrasound (R-EBUS) guided flexible bronchoscopy (FB). However, data regarding the diagnostic performances among bronchoscopic sampling techniques is limited. This study was conducted to compare the diagnostic yields among bronchoscopic sampling techniques in the diagnosis of peripheral pulmonary lesions (PPLs). A prospective study was conducted on 112 patients who were diagnosed with PPLs and underwent R-EBUS-guided FB between Oct 2012 and Sep 2014. Sampling techniques-including transbronchial biopsy (TBB), brushing cell block, brushing smear, rinsed fluid of brushing, and bronchoalveolar lavage (BAL)-were evaluated for the diagnosis. The mean diameter of the PPLs was 23.5±9.5 mm. The final diagnoses included 76 malignancies and 36 benign lesions. The overall diagnostic yield of R-EBUS-guided bronchoscopy was 80.4%; TBB gave the highest yield among the 112 specimens: 70.5%, 34.8%, 62.5%, 50.0% and 42.0% for TBB, brushing cell block, brushing smear, rinsed brushing fluid, and BAL fluid (BALF), respectively (P<0.001). TBB provided high diagnostic yield irrespective of the size and etiology of the PPLs. The combination of TBB and brushing smear achieved the maximum diagnostic yield. Of 31 infectious PPLs, BALF culture gave additional microbiological information in 20 cases. TBB provided the highest diagnostic yield; however, to achieve the highest diagnostic performance, TBB, brushing smear and BAL techniques should be performed together.

Rapid diagnostic tests for malaria

PubMed Central

Daily, Jennifer; Hotte, Nora; Dolkart, Caitlin; Cunningham, Jane; Yadav, Prashant

2015-01-01

Abstract Maintaining quality, competitiveness and innovation in global health technology is a constant challenge for manufacturers, while affordability, access and equity are challenges for governments and international agencies. In this paper we discuss these issues with reference to rapid diagnostic tests for malaria. Strategies to control and eliminate malaria depend on early and accurate diagnosis. Rapid diagnostic tests for malaria require little training and equipment and can be performed by non-specialists in remote settings. Use of these tests has expanded significantly over the last few years, following recommendations to test all suspected malaria cases before treatment and the implementation of an evaluation programme to assess the performance of the malaria rapid diagnostic tests. Despite these gains, challenges exist that, if not addressed, could jeopardize the progress made to date. We discuss recent developments in rapid diagnostic tests for malaria, highlight some of the challenges and provide suggestions to address them. PMID:26668438

Novel Breast Imaging and Machine Learning: Predicting Breast Lesion Malignancy at Cone-Beam CT Using Machine Learning Techniques.

PubMed

Uhlig, Johannes; Uhlig, Annemarie; Kunze, Meike; Beissbarth, Tim; Fischer, Uwe; Lotz, Joachim; Wienbeck, Susanne

2018-05-24

The purpose of this study is to evaluate the diagnostic performance of machine learning techniques for malignancy prediction at breast cone-beam CT (CBCT) and to compare them to human readers. Five machine learning techniques, including random forests, back propagation neural networks (BPN), extreme learning machines, support vector machines, and K-nearest neighbors, were used to train diagnostic models on a clinical breast CBCT dataset with internal validation by repeated 10-fold cross-validation. Two independent blinded human readers with profound experience in breast imaging and breast CBCT analyzed the same CBCT dataset. Diagnostic performance was compared using AUC, sensitivity, and specificity. The clinical dataset comprised 35 patients (American College of Radiology density type C and D breasts) with 81 suspicious breast lesions examined with contrast-enhanced breast CBCT. Forty-five lesions were histopathologically proven to be malignant. Among the machine learning techniques, BPNs provided the best diagnostic performance, with AUC of 0.91, sensitivity of 0.85, and specificity of 0.82. The diagnostic performance of the human readers was AUC of 0.84, sensitivity of 0.89, and specificity of 0.72 for reader 1 and AUC of 0.72, sensitivity of 0.71, and specificity of 0.67 for reader 2. AUC was significantly higher for BPN when compared with both reader 1 (p = 0.01) and reader 2 (p < 0.001). Machine learning techniques provide a high and robust diagnostic performance in the prediction of malignancy in breast lesions identified at CBCT. BPNs showed the best diagnostic performance, surpassing human readers in terms of AUC and specificity.

Specialized data analysis for the Space Shuttle Main Engine and diagnostic evaluation of advanced propulsion system components

NASA Technical Reports Server (NTRS)

1993-01-01

The Marshall Space Flight Center is responsible for the development and management of advanced launch vehicle propulsion systems, including the Space Shuttle Main Engine (SSME), which is presently operational, and the Space Transportation Main Engine (STME) under development. The SSME's provide high performance within stringent constraints on size, weight, and reliability. Based on operational experience, continuous design improvement is in progress to enhance system durability and reliability. Specialized data analysis and interpretation is required in support of SSME and advanced propulsion system diagnostic evaluations. Comprehensive evaluation of the dynamic measurements obtained from test and flight operations is necessary to provide timely assessment of the vibrational characteristics indicating the operational status of turbomachinery and other critical engine components. Efficient performance of this effort is critical due to the significant impact of dynamic evaluation results on ground test and launch schedules, and requires direct familiarity with SSME and derivative systems, test data acquisition, and diagnostic software. Detailed analysis and evaluation of dynamic measurements obtained during SSME and advanced system ground test and flight operations was performed including analytical/statistical assessment of component dynamic behavior, and the development and implementation of analytical/statistical models to efficiently define nominal component dynamic characteristics, detect anomalous behavior, and assess machinery operational condition. In addition, the SSME and J-2 data will be applied to develop vibroacoustic environments for advanced propulsion system components, as required. This study will provide timely assessment of engine component operational status, identify probable causes of malfunction, and indicate feasible engineering solutions. This contract will be performed through accomplishment of negotiated task orders.

The Arthroscopic Surgical Skill Evaluation Tool (ASSET).

PubMed

Koehler, Ryan J; Amsdell, Simon; Arendt, Elizabeth A; Bisson, Leslie J; Braman, Jonathan P; Bramen, Jonathan P; Butler, Aaron; Cosgarea, Andrew J; Harner, Christopher D; Garrett, William E; Olson, Tyson; Warme, Winston J; Nicandri, Gregg T

2013-06-01

Surgeries employing arthroscopic techniques are among the most commonly performed in orthopaedic clinical practice; however, valid and reliable methods of assessing the arthroscopic skill of orthopaedic surgeons are lacking. The Arthroscopic Surgery Skill Evaluation Tool (ASSET) will demonstrate content validity, concurrent criterion-oriented validity, and reliability when used to assess the technical ability of surgeons performing diagnostic knee arthroscopic surgery on cadaveric specimens. Cross-sectional study; Level of evidence, 3. Content validity was determined by a group of 7 experts using the Delphi method. Intra-articular performance of a right and left diagnostic knee arthroscopic procedure was recorded for 28 residents and 2 sports medicine fellowship-trained attending surgeons. Surgeon performance was assessed by 2 blinded raters using the ASSET. Concurrent criterion-oriented validity, interrater reliability, and test-retest reliability were evaluated. Content validity: The content development group identified 8 arthroscopic skill domains to evaluate using the ASSET. Concurrent criterion-oriented validity: Significant differences in the total ASSET score (P < .05) between novice, intermediate, and advanced experience groups were identified. Interrater reliability: The ASSET scores assigned by each rater were strongly correlated (r = 0.91, P < .01), and the intraclass correlation coefficient between raters for the total ASSET score was 0.90. Test-retest reliability: There was a significant correlation between ASSET scores for both procedures attempted by each surgeon (r = 0.79, P < .01). The ASSET appears to be a useful, valid, and reliable method for assessing surgeon performance of diagnostic knee arthroscopic surgery in cadaveric specimens. Studies are ongoing to determine its generalizability to other procedures as well as to the live operating room and other simulated environments.

Comparative Evaluation of 11 Commercialized Rapid Diagnostic Tests for Detecting Trypanosoma cruzi Antibodies in Serum Banks in Areas of Endemicity and Nonendemicity

PubMed Central

Albajar-Viñas, Pedro; Wilkins, Patricia P.; Nieto, Javier; Leiby, David A.; Paris, Luc; Scollo, Karenina; Flórez, Carolina; Guzmán-Bracho, Carmen; Luquetti, Alejandro O.; Calvo, Nidia; Tadokoro, Kenji; Saez-Alquezar, Amadeo; Palma, Pedro Pablo; Martin, Miguel

2014-01-01

Chagas disease is one of the main public health issues in Latin America. Increasingly during the past few decades, Trypanosoma cruzi infection has been detected in North America, Europe, and the Western Pacific, mainly as a result of population movement. The limited availability of rapid serological diagnostic tests hinders rapid diagnosis and early treatment in areas of endemicity and nonendemicity. In collaboration with 11 national reference laboratories (NRLs) from different geographical areas, we evaluated the performances of commercialized serological rapid diagnostic tests (RDT) for T. cruzi infection. Eleven commercialized T. cruzi infection RDTs were evaluated on a total of 474 samples extensively tested with at least three different techniques for Chagas disease, maintained at controlled low temperatures, and stored in the serum banks of the 11 NRLs. We measured the sensitivity, specificity, and concordance of each RDT and provided an additional questionnaire to evaluate its ease of use. The selected RDTs in this study were performed under controlled laboratory conditions. Out of the 11 RDTs, we found 8 of them to be useful, with the cassette format favored over the strip. We did not observe significant differences in RDT performances in the different regions. Overall, the performance results were lower than those disclosed by the manufacturers. The results of this evaluation validate the possibility of using RDTs to diagnose Chagas disease, thereby decreasing the time to treatment at a primary health care facility for patients who are willing to be treated. Further studies should be conducted in the laboratory and in the field to confirm these data, expressly to evaluate reproducibility in resource-limited settings, or using whole blood in clinical settings in areas of endemicity and nonendemicity. PMID:24808239

Diagnostic accuracy of dual-source computed tomography angiography for the detection of coronary in-stent restenosis: A systematic review and meta-analysis.

PubMed

Liu, Wen-Jun; Li, Gui-Zhen; Liu, Hai-Feng; Lei, Jun-Qiang

2018-04-01

We sought to perform a meta-analysis to comprehensively evaluate the diagnostic accuracy of dual-source computed tomography angiography (DSCTA) in detecting coronary in-stent restenosis (CISR) when compared to invasive coronary angiography. The stent-based research studies in which DSCTA was used as diagnostic tool for CISR, as recent as of October 2017, from several reputed scientific libraries (PubMed, Embase, Scopus, The Cochrane Library, and Web of Science) were evaluated. Study inclusion, data extraction, and risk bias assessment were conducted by two researchers independently. Pooled sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under summary receiver operator characteristics (SROC) curve (AUC) were calculated to assess the diagnostic value. In addition, heterogeneity and subgroup analysis were also carried out. A total of 13 studies with a total of 894 patients and 1384 assessable stents were included. The pooled results of DSCTA diagnosing CISR were as follows: SEN 0.92 (95% confidence interval [CI] 0.87-0.96), SPE 0.91 (95% CI 0.87-0.94), PLR 9.83 (95% CI 6.93-13.94), NLR 0.09 (95% CI 0.05-0.15), DOR 114.73 (95% CI 64.12-205.28), and AUC 0.97 (95% CI 0.95-0.98), respectively. The subgroup analysis result suggested that DSTCA performed significantly better in CISR detection when the stent diameter was ≥3 mm compared with the stent diameter <3 mm: (0.98 [0.97-0.99] vs 0.82 [0.79-0.86]) with P < .05. This study revealed that DSCTA has excellent diagnostic performance for detecting CISR and may serve as an alternative for further patient evaluation with CISR, especially for stent diameter ≥3 mm. © 2018 Wiley Periodicals, Inc.

Laparoscopic management and its outcomes in cases with nonpalpable testis.

PubMed

Erdoğan, Cankat; Bahadır, Berktuğ; Taşkınlar, Hakan; Naycı, Ali

2017-06-01

Diagnostic laparoscopy is the gold standard in the algorithm of nonpalpable testis. Testicular tissue is examined and treatment is planned accordingly. In this study we reviewed the place of diagnostic laparoscopy, and evaluated the results and effectiveness of laparoscopy in the diagnosis and management of nonpalpable testis. Children who had diagnostic laparoscopy for nonpalpable testes were included in the study. Physical examination results, ultrasonography (USG) reports, age at surgery, laparoscopic and inguinal exploration findings, surgical procedures, orchiopexy results, early and late-term complications were evaluated. Follow-up visits were performed at 3-month intervals for the first, at 6-month intervals for the 2. year, then at yearly intervals. Testicular size and location was evaluated by during control examination. Overall 58 boys, and 68 testes (26 left: 44.8%; 22 right: 37.9%, and 10 bilateral: 17.2%) were included in the study. Mean age at surgery was 5.5 years (10 months-17 years). Diagnostic value of USG was 15.7%. Diagnostic laparoscopy findings were as follows: Group 1: blind-ended vessels, n=7 (10.2%); Group 2: intraabdominal testes, n=8 (11.7%); Group 3: vas and vessels entering internal ring, n=53 (77.9%). Overall 43 testes underwent orchiopexy, which were normal (n=8) or hypoplastic (n=35). Mean follow-up period was 19 months (1-12 years), and on an average 7 visits were performed (5-14). On follow-up, 5 testes were normal-sized and located in the scrotum, while 4 testes were atrophic and underwent orchiectomy. Two testes were found in the inguinal canal and redo orchiopexy was performed. Control USG revealed reduced testicular blood supply and volume. Laparoscopic surgery is safe and effective in the management of nonpalpable testes. In the majority, routine use of diagnostic laparoscopy in the algorithma does not confer any additional contributions in many patients.

Propulsion IVHM Technology Experiment

NASA Technical Reports Server (NTRS)

Chicatelli, Amy K.; Maul, William A.; Fulton, Christopher E.

2006-01-01

The Propulsion IVHM Technology Experiment (PITEX) successfully demonstrated real-time fault detection and isolation of a virtual reusable launch vehicle (RLV) main propulsion system (MPS). Specifically, the PITEX research project developed and applied a model-based diagnostic system for the MPS of the X-34 RLV, a space-launch technology demonstrator. The demonstration was simulation-based using detailed models of the propulsion subsystem to generate nominal and failure scenarios during captive carry, which is the most safety-critical portion of the X-34 flight. Since no system-level testing of the X-34 Main Propulsion System (MPS) was performed, these simulated data were used to verify and validate the software system. Advanced diagnostic and signal processing algorithms were developed and tested in real time on flight-like hardware. In an attempt to expose potential performance problems, the PITEX diagnostic system was subjected to numerous realistic effects in the simulated data including noise, sensor resolution, command/valve talkback information, and nominal build variations. In all cases, the PITEX system performed as required. The research demonstrated potential benefits of model-based diagnostics, defined performance metrics required to evaluate the diagnostic system, and studied the impact of real-world challenges encountered when monitoring propulsion subsystems.

Evaluation of the accuracy of the EasyTest™ malaria Pf/Pan Ag, a rapid diagnostic test, in Uganda.

PubMed

Chong, Chom-Kyu; Cho, Pyo Yun; Na, Byoung-Kuk; Ahn, Seong Kyu; Kim, Jin Su; Lee, Jin-Soo; Lee, Sung-Keun; Han, Eun-Taek; Kim, Hak-Yong; Park, Yun-Kyu; Cha, Seok Ho; Kim, Tong-Soo

2014-10-01

In recent years, rapid diagnostic tests (RDTs) have been widely used for malaria detection, primarily because of their simple operation, fast results, and straightforward interpretation. The Asan EasyTest™ Malaria Pf/Pan Ag is one of the most commonly used malaria RDTs in several countries, including Korea and India. In this study, we tested the diagnostic performance of this RDT in Uganda to evaluate its usefulness for field diagnosis of malaria in this country. Microscopic and PCR analyses, and the Asan EasyTest™ Malaria Pf/Pan Ag rapid diagnostic test, were performed on blood samples from 185 individuals with suspected malaria in several villages in Uganda. Compared to the microscopic analysis, the sensitivity of the RDT to detect malaria infection was 95.8% and 83.3% for Plasmodium falciparum and non-P. falciparum, respectively. Although the diagnostic sensitivity of the RDT decreased when parasitemia was ≤500 parasites/µl, it showed 96.8% sensitivity (98.4% for P. falciparum and 93.8% for non-P. falciparum) in blood samples with parasitemia ≥100 parasites/µl. The specificity of the RDT was 97.3% for P. falciparum and 97.3% for non-P. falciparum. These results collectively suggest that the accuracy of the Asan EasyTest™ Malaria Pf/Pan Ag makes it an effective point-of-care diagnostic tool for malaria in Uganda.

Evaluation of the Accuracy of the EasyTest™ Malaria Pf/Pan Ag, a Rapid Diagnostic Test, in Uganda

PubMed Central

Chong, Chom-Kyu; Cho, Pyo Yun; Na, Byoung-Kuk; Ahn, Seong Kyu; Kim, Jin Su; Lee, Jin-Soo; Lee, Sung-Keun; Han, Eun-Taek; Kim, Hak-Yong; Park, Yun-Kyu; Cha, Seok Ho

2014-01-01

In recent years, rapid diagnostic tests (RDTs) have been widely used for malaria detection, primarily because of their simple operation, fast results, and straightforward interpretation. The Asan EasyTest™ Malaria Pf/Pan Ag is one of the most commonly used malaria RDTs in several countries, including Korea and India. In this study, we tested the diagnostic performance of this RDT in Uganda to evaluate its usefulness for field diagnosis of malaria in this country. Microscopic and PCR analyses, and the Asan EasyTest™ Malaria Pf/Pan Ag rapid diagnostic test, were performed on blood samples from 185 individuals with suspected malaria in several villages in Uganda. Compared to the microscopic analysis, the sensitivity of the RDT to detect malaria infection was 95.8% and 83.3% for Plasmodium falciparum and non-P. falciparum, respectively. Although the diagnostic sensitivity of the RDT decreased when parasitemia was ≤500 parasites/µl, it showed 96.8% sensitivity (98.4% for P. falciparum and 93.8% for non-P. falciparum) in blood samples with parasitemia ≥100 parasites/µl. The specificity of the RDT was 97.3% for P. falciparum and 97.3% for non-P. falciparum. These results collectively suggest that the accuracy of the Asan EasyTest™ Malaria Pf/Pan Ag makes it an effective point-of-care diagnostic tool for malaria in Uganda. PMID:25352698

[Situational diagnostic of an evaluation process of professional perfomance].

PubMed

Gonçalves, Vera Lúcia Mira; Leite, Maria Madalena Januário

2004-01-01

The aim of this study was to realize a diagnostic situational about the evaluation process of the nursing team performance of USP Hospital. Based in two guiding questions, it was carried out 9 interviews with nurses of this hospital. These interviews were analyzed according Analyze of Contend. The most frequent themes were: The meaning of evaluation; the feelings; the difficulties and facilities concerning the instrument and the capacitacion. This experience brought about many feelings, as well as aspects that either favor or make the execution of the evaluation difficult, showing the principal points of vulnerability of the process and, therefore, deserving better attention and short-term intervention.

The diagnostic performance of coronary artery angiography with 64-MSCT and post 64-MSCT: systematic review and meta-analysis.

PubMed

Li, Min; Du, Xiang-Min; Jin, Zhi-Tao; Peng, Zhao-Hui; Ding, Juan; Li, Li

2014-01-01

To comprehensively investigate the diagnostic performance of coronary artery angiography with 64-MDCT and post 64-MDCT. PubMed was searched for all published studies that evaluated coronary arteries with 64-MDCT and post 64-MDCT. The clinical diagnostic role was evaluated by applying the likelihood ratios (LRs) to calculate the post-test probability based on Bayes' theorem. 91 studies that met our inclusion criteria were ultimately included in the analysis. The pooled positive and negative LRs at patient level were 8.91 (95% CI, 7.53, 10.54) and 0.02 (CI, 0.01, 0.03), respectively. For studies that did not claim that non-evaluable segments were included, the pooled positive and negative LRs were 11.16 (CI, 8.90, 14.00) and 0.01 (CI, 0.01, 0.03), respectively. For studies including uninterruptable results, the diagnostic performance decreased, with the pooled positive LR 7.40 (CI, 6.00, 9.13) and negative LR 0.02 (CI, 0.01, 0.03). The areas under the summary ROC curve were 0.98 (CI, 0.97 to 0.99) for 64-MDCT and 0.96 (CI, 0.94 to 0.98) for post 64-MDCT, respectively. For references explicitly stating that the non-assessable segments were included during analysis, a post-test probability of negative results >95% and a positive post-test probability <95% could be obtained for patients with a pre-test probability of <73% for coronary artery disease (CAD). On the other hand, when the pre-test probability of CAD was >73%, the diagnostic role was reversed, with a positive post-test probability of CAD >95% and a negative post-test probability of CAD <95%. The diagnostic performance of post 64-MDCT does not increase as compared with 64-MDCT. CTA, overall, is a test of exclusion for patients with a pre-test probability of CAD<73%, while for patients with a pre-test probability of CAD>73%, CTA is a test used to confirm the presence of CAD.

3D isotropic T2-weighted fast spin echo (VISTA) versus 2D T2-weighted fast spin echo in evaluation of the calcaneofibular ligament in the oblique coronal plane.

PubMed

Park, H J; Lee, S Y; Choi, Y J; Hong, H P; Park, S J; Park, J H; Kim, E

2017-02-01

To investigate whether the image quality of three-dimensional (3D) volume isotropic fast spin echo acquisition (VISTA) magnetic resonance imaging (MRI) of the calcaneofibular ligament (CFL) view is comparable to that of 2D fast spin echo T2-weighted images (2D T2 FSE) for the evaluation of the CFL, and whether 3D VISTA can replace 2D T2 FSE for the evaluation of CFL injuries. This retrospective study included 76 patients who underwent ankle MRI with CFL views of both 2D T2 FSE MRI and 3D VISTA. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of both techniques were measured. The anatomical identification score and diagnostic performances were evaluated by two readers independently. The diagnostic performances of 3D VISTA and 2D T2 FSE were analysed by sensitivity, specificity, and accuracy for diagnosing CFL injury with reference standards of surgically or clinically confirmed diagnoses. Surgical correlation was performed in 29% of the patients, and clinical examination was used in those who did not have surgery (71%). The SNRs and CNRs of 3D VISTA were significantly higher than those of 2D T2 FSE. The anatomical identification scores on 3D VISTA were inferior to those on 2D T2 FSE, and the differences were statistically significant (p<0.05). There were no significant differences in diagnostic performance between the two sequences when diagnoses were classified as normal or abnormal. Although the image quality of 3D VISTA MRI of the CFL view is not equal to that of 2D T2 FSE for the anatomical evaluation of CFL, 3D VISTA has a diagnostic performance comparable to that of 2D T2 FSE for the diagnosis of CFL injuries. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Measures to Improve Diagnostic Safety in Clinical Practice.

PubMed

Singh, Hardeep; Graber, Mark L; Hofer, Timothy P

2016-10-20

Timely and accurate diagnosis is foundational to good clinical practice and an essential first step to achieving optimal patient outcomes. However, a recent Institute of Medicine report concluded that most of us will experience at least one diagnostic error in our lifetime. The report argues for efforts to improve the reliability of the diagnostic process through better measurement of diagnostic performance. The diagnostic process is a dynamic team-based activity that involves uncertainty, plays out over time, and requires effective communication and collaboration among multiple clinicians, diagnostic services, and the patient. Thus, it poses special challenges for measurement. In this paper, we discuss how the need to develop measures to improve diagnostic performance could move forward at a time when the scientific foundation needed to inform measurement is still evolving. We highlight challenges and opportunities for developing potential measures of "diagnostic safety" related to clinical diagnostic errors and associated preventable diagnostic harm. In doing so, we propose a starter set of measurement concepts for initial consideration that seem reasonably related to diagnostic safety and call for these to be studied and further refined. This would enable safe diagnosis to become an organizational priority and facilitate quality improvement. Health-care systems should consider measurement and evaluation of diagnostic performance as essential to timely and accurate diagnosis and to the reduction of preventable diagnostic harm.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

Re-evaluation of a novel approach for quantitative myocardial oedema detection by analysing tissue inhomogeneity in acute myocarditis using T2-mapping.

PubMed

Baeßler, Bettina; Schaarschmidt, Frank; Treutlein, Melanie; Stehning, Christian; Schnackenburg, Bernhard; Michels, Guido; Maintz, David; Bunck, Alexander C

2017-12-01

To re-evaluate a recently suggested approach of quantifying myocardial oedema and increased tissue inhomogeneity in myocarditis by T2-mapping. Cardiac magnetic resonance data of 99 patients with myocarditis were retrospectively analysed. Thirthy healthy volunteers served as controls. T2-mapping data were acquired at 1.5 T using a gradient-spin-echo T2-mapping sequence. T2-maps were segmented according to the 16-segments AHA-model. Segmental T2-values, segmental pixel-standard deviation (SD) and the derived parameters maxT2, maxSD and madSD were analysed and compared to the established Lake Louise criteria (LLC). A re-estimation of logistic regression models revealed that all models containing an SD-parameter were superior to any model containing global myocardial T2. Using a combined cut-off of 1.8 ms for madSD + 68 ms for maxT2 resulted in a diagnostic sensitivity of 75% and specificity of 80% and showed a similar diagnostic performance compared to LLC in receiver-operating-curve analyses. Combining madSD, maxT2 and late gadolinium enhancement (LGE) in a model resulted in a superior diagnostic performance compared to LLC (sensitivity 93%, specificity 83%). The results show that the novel T2-mapping-derived parameters exhibit an additional diagnostic value over LGE with the inherent potential to overcome the current limitations of T2-mapping. • A novel quantitative approach to myocardial oedema imaging in myocarditis was re-evaluated. • The T2-mapping-derived parameters maxT2 and madSD were compared to traditional Lake-Louise criteria. • Using maxT2 and madSD with dedicated cut-offs performs similarly to Lake-Louise criteria. • Adding maxT2 and madSD to LGE results in further increased diagnostic performance. • This novel approach has the potential to overcome the limitations of T2-mapping.

Detection of respiratory bacterial pathogens causing atypical pneumonia by multiplex Lightmix® RT-PCR.

PubMed

Wagner, Karoline; Springer, Burkard; Imkamp, Frank; Opota, Onya; Greub, Gilbert; Keller, Peter M

2018-04-01

Pneumonia is a severe infectious disease. In addition to common viruses and bacterial pathogens (e.g. Streptococcus pneumoniae), fastidious respiratory pathogens like Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella spp. can cause severe atypical pneumonia. They do not respond to penicillin derivatives, which may cause failure of antibiotic empirical therapy. The same applies for infections with B. pertussis and B. parapertussis, the cause of pertussis disease, that may present atypically and need to be treated with macrolides. Moreover, these fastidious bacteria are difficult to identify by culture or serology, and therefore often remain undetected. Thus, rapid and accurate identification of bacterial pathogens causing atypical pneumonia is crucial. We performed a retrospective method evaluation study to evaluate the diagnostic performance of the new, commercially available Lightmix ® multiplex RT-PCR assay that detects these fastidious bacterial pathogens causing atypical pneumonia. In this retrospective study, 368 clinical respiratory specimens, obtained from patients suffering from atypical pneumonia that have been tested negative for the presence of common agents of pneumonia by culture and viral PCR, were investigated. These clinical specimens have been previously characterized by singleplex RT-PCR assays in our diagnostic laboratory and were used to evaluate the diagnostic performance of the respiratory multiplex Lightmix ® RT-PCR. The multiplex RT-PCR displayed a limit of detection between 5 and 10 DNA copies for different in-panel organisms and showed identical performance characteristics with respect to specificity and sensitivity as in-house singleplex RT-PCRs for pathogen detection. The Lightmix ® multiplex RT-PCR assay represents a low-cost, time-saving and accurate diagnostic tool with high throughput potential. The time-to-result using an automated DNA extraction device for respiratory specimens followed by multiplex RT-PCR detection was below 4 h, which is expected to significantly improve diagnostics for atypical pneumonia-associated bacterial pathogens. Copyright © 2018 The Authors. Published by Elsevier GmbH.. All rights reserved.

Identifying influential data points in hydrological model calibration and their impact on streamflow predictions

NASA Astrophysics Data System (ADS)

Wright, David; Thyer, Mark; Westra, Seth

2015-04-01

Highly influential data points are those that have a disproportionately large impact on model performance, parameters and predictions. However, in current hydrological modelling practice the relative influence of individual data points on hydrological model calibration is not commonly evaluated. This presentation illustrates and evaluates several influence diagnostics tools that hydrological modellers can use to assess the relative influence of data. The feasibility and importance of including influence detection diagnostics as a standard tool in hydrological model calibration is discussed. Two classes of influence diagnostics are evaluated: (1) computationally demanding numerical "case deletion" diagnostics; and (2) computationally efficient analytical diagnostics, based on Cook's distance. These diagnostics are compared against hydrologically orientated diagnostics that describe changes in the model parameters (measured through the Mahalanobis distance), performance (objective function displacement) and predictions (mean and maximum streamflow). These influence diagnostics are applied to two case studies: a stage/discharge rating curve model, and a conceptual rainfall-runoff model (GR4J). Removing a single data point from the calibration resulted in differences to mean flow predictions of up to 6% for the rating curve model, and differences to mean and maximum flow predictions of up to 10% and 17%, respectively, for the hydrological model. When using the Nash-Sutcliffe efficiency in calibration, the computationally cheaper Cook's distance metrics produce similar results to the case-deletion metrics at a fraction of the computational cost. However, Cooks distance is adapted from linear regression with inherit assumptions on the data and is therefore less flexible than case deletion. Influential point detection diagnostics show great potential to improve current hydrological modelling practices by identifying highly influential data points. The findings of this study establish the feasibility and importance of including influential point detection diagnostics as a standard tool in hydrological model calibration. They provide the hydrologist with important information on whether model calibration is susceptible to a small number of highly influent data points. This enables the hydrologist to make a more informed decision of whether to (1) remove/retain the calibration data; (2) adjust the calibration strategy and/or hydrological model to reduce the susceptibility of model predictions to a small number of influential observations.

[Diagnostic kits in parasitology: which controls?].

PubMed

Rossi, P

2004-06-01

The development of new diagnostic tools particularly for some parasitic "neglected diseases", is slowed or even hindered by limited resources assigned for basic and applied research in public institution and private sector. Even if the time-line and costs needed for developing a new In Vitro Diagnostic (IVD) test are generally lower compared to vaccines or new drugs, industry is poorly engaged in investing resources due to the perception of limited markets. To accelerate the development of diagnostics for the world's most deadly diseases, the World Health Organization's (WHO) Special Programme for Research and Training in Tropical Diseases (TDR), the United Nations Development Programme, the World Bank and the Gates Foundation, last year launched a new initiative, FIND (Foundation for Innovative New Diagnostics, www.finddiagnostics.org). The aim is to "apply the latest biotechnology innovations to develop and validate affordable diagnostic tests for diseases of the developing world". Ideally, a new diagnostic test should be accurately evaluated prior to use in medical practice. The first step would be a pre-clinical evaluation, an analytic study to determine its laboratory performance. A crucial point in this phase is the calibration of reagents (antigens, antibodies, DNA probes, etc.) against a standard reference preparation. WHO, through the WHO International Laboratories for Biological Standards, "provides International Biological Reference Preparations which serve as reference sources of defined biological activity expressed in an internationally agreed unit" (www.who.int/biologicals/IBRP/index.htm). Standardization allows "comparison of biological measurements worldwide" and ensures the reliability of diagnostic procedures. These preparations are generally intended for use in the characterization of the activity of secondary reference preparations (regional, national or in-house working standards). Unfortunately, international reference standards for parasitic diseases are not available at present, except for Toxoplasma antibodies. The first international standard reagent for Anti-Toxoplasma Serum was established in 1968 and at present, an international standard reference serum, Anti-toxoplasma serum, human TOXM is available at the National Institute for Biological Standards and Control (NIBSC) in UK. Several collaborative, multicenter studies were carried out to assess the performance of different methods and commercial tests for the diagnosis of toxoplasmosis, by providing to participating laboratories a panel of well-defined sera to be tested. A four-phase process following well-accepted methodological standards for the development of diagnostics, analogous to those internationally accepted for drugs and vaccines was recently proposed. The pre-clinical evaluation, the analytic study to assess sensitivity, specificity, predictive values in laboratory (phase I), should be followed by a proof of principle study to distinguish diseased from healthy persons in easily accessible populations (phase II). The evaluation of test performance in populations of intended use (phase III), and finally the delineation of cost-effectiveness and societal impact of new tests in comparison with existing tools (phase IV) should complete the validation procedure. In this context, national regulatory agencies play a major role in pre-market approval and post-market surveillance of IVDs. The European Community in 1998 approved a directive (Directive 98/79/EC) which rules the marketing of IVD medical devices, in order to harmonise the performance levels and standards in European countries. But, among IVDs for parasitic diseases, only those to detect congenital toxoplasmosis are submitted to defined procedures to provide the verification of products before their placing on the market and the surveillance after their marketing by a notified body, which perform appropriate examinations, tests and inspections to production facilities to verify if the device meets the requirements of the directive. In U.S.A., the Food and Drug Administration (FDA), through the Office of In Vitro Diagnostic Device Evaluation and Safety (OIVD), provides a comprehensive and regulatory activity for IVDs through pre-market evaluation and post-market surveillance. In developing countries, the scarcity of resources limits the procedures through which the national control authority can assure safety, quality and efficacy of products marketed, both imported and locally manufactured.

Feasibility and Safety of Evaluating Patients with Prior Coronary Artery Disease Using an Accelerated Diagnostic Algorithm in a Chest Pain Unit

PubMed Central

Goldkorn, Ronen; Goitein, Orly; Ben-Zekery, Sagit; Shlomo, Nir; Narodetsky, Michael; Livne, Moran; Sabbag, Avi; Asher, Elad; Matetzky, Shlomi

2016-01-01

An accelerated diagnostic protocol for evaluating low-risk patients with acute chest pain in a cardiologist-based chest pain unit (CPU) is widely employed today. However, limited data exist regarding the feasibility of such an algorithm for patients with a history of prior coronary artery disease (CAD). The aim of the current study was to assess the feasibility and safety of evaluating patients with a history of prior CAD using an accelerated diagnostic protocol. We evaluated 1,220 consecutive patients presenting with acute chest pain and hospitalized in our CPU. Patients were stratified according to whether they had a history of prior CAD or not. The primary composite outcome was defined as a composite of readmission due to chest pain, acute coronary syndrome, coronary revascularization, or death during a 60-day follow-up period. Overall, 268 (22%) patients had a history of prior CAD. Non-invasive evaluation was performed in 1,112 (91%) patients. While patients with a history of prior CAD had more comorbidities, the two study groups were similar regarding hospitalization rates (9% vs. 13%, p = 0.08), coronary angiography (13% vs. 11%, p = 0.41), and revascularization (6.5% vs. 5.7%, p = 0.8) performed during CPU evaluation. At 60-days the primary endpoint was observed in 12 (1.6%) and 6 (3.2%) patients without and with a history of prior CAD, respectively (p = 0.836). No mortalities were recorded. To conclude, Patients with a history of prior CAD can be expeditiously and safely evaluated using an accelerated diagnostic protocol in a CPU with outcomes not differing from patients without such a history. PMID:27669521

Reduction of bias and variance for evaluation of computer-aided diagnostic schemes.

PubMed

Li, Qiang; Doi, Kunio

2006-04-01

Computer-aided diagnostic (CAD) schemes have been developed to assist radiologists in detecting various lesions in medical images. In addition to the development, an equally important problem is the reliable evaluation of the performance levels of various CAD schemes. It is good to see that more and more investigators are employing more reliable evaluation methods such as leave-one-out and cross validation, instead of less reliable methods such as resubstitution, for assessing their CAD schemes. However, the common applications of leave-one-out and cross-validation evaluation methods do not necessarily imply that the estimated performance levels are accurate and precise. Pitfalls often occur in the use of leave-one-out and cross-validation evaluation methods, and they lead to unreliable estimation of performance levels. In this study, we first identified a number of typical pitfalls for the evaluation of CAD schemes, and conducted a Monte Carlo simulation experiment for each of the pitfalls to demonstrate quantitatively the extent of bias and/or variance caused by the pitfall. Our experimental results indicate that considerable bias and variance may exist in the estimated performance levels of CAD schemes if one employs various flawed leave-one-out and cross-validation evaluation methods. In addition, for promoting and utilizing a high standard for reliable evaluation of CAD schemes, we attempt to make recommendations, whenever possible, for overcoming these pitfalls. We believe that, with the recommended evaluation methods, we can considerably reduce the bias and variance in the estimated performance levels of CAD schemes.

Diagnosis of aphasia in stroke populations: A systematic review of language tests

PubMed Central

2018-01-01

Background and purpose Accurate aphasia diagnosis is important in stroke care. A wide range of language tests are available and include informal assessments, tests developed by healthcare institutions and commercially published tests available for purchase in pre-packaged kits. The psychometrics of these tests are often reported online or within the purchased test manuals, not the peer-reviewed literature, therefore the diagnostic capabilities of these measures have not been systematically evaluated. This review aimed to identify both commercial and non-commercial language tests and tests used in stroke care and to examine the diagnostic capabilities of all identified measures in diagnosing aphasia in stroke populations. Methods Language tests were identified through a systematic search of 161 publisher databases, professional and resource websites and language tests reported to be used in stroke care. Two independent reviewers evaluated test manuals or associated resources for cohort or cross-sectional studies reporting the tests’ diagnostic capabilities (sensitivity, specificity, likelihood ratios or diagnostic odds ratios) in differentiating aphasic and non-aphasic stroke populations. Results Fifty-six tests met the study eligibility criteria. Six “non-specialist” brief screening tests reported sensitivity and specificity information, however none of these measures reported to meet the specific diagnostic needs of speech pathologists. The 50 remaining measures either did not report validity data (n = 7); did not compare patient test performance with a comparison group (n = 17); included non-stroke participants within their samples (n = 23) or did not compare stroke patient performance against a language reference standard (n = 3). Diagnostic sensitivity analysis was completed for six speech pathology measures (WAB, PICA, CADL-2, ASHA-FACS, Adult FAVRES and EFA-4), however all studies compared aphasic performance with that of non-stroke healthy controls and were consequently excluded from the review. Conclusions No speech pathology test was found which reported diagnostic data for identifying aphasia in stroke populations. A diagnostically validated post-stroke aphasia test is needed. PMID:29566043

Incidence and predictors of silent embolic cerebral infarction following diagnostic coronary angiography.

PubMed

Kim, In-Cheol; Hur, Seung-Ho; Park, Nam-Hee; Jun, Dong-Hwan; Cho, Yun-Kyeong; Nam, Chang-Wook; Kim, Hyungseop; Han, Seong-Wook; Choi, Sae-Young; Kim, Yoon-Nyun; Kim, Kwon-Bae

2011-04-14

Coronary angiography (CAG) is an invasive diagnostic procedure, which could lead to procedure related complications. One of the well known post-procedural complications is cerebral embolic infarction with or without symptoms. Silent embolic cerebral infarction (SECI) has clinical significance because it can progress to a decline in cognitive function and increase the risk of dementia in the long term. The aim of this study was to detect the incidence and predictors of SECI after diagnostic CAG using diffusion-weighted magnetic resonance imaging (DW-MRI). A total of 197 patients with coronary artery disease who underwent DW-MRI for evaluation of intracranial vasculopathy before coronary artery bypass graft surgery were retrospectively enrolled in the present study. DW-MRI was performed within 48 h after diagnostic CAG. SECI was diagnosed as presence of focal bright high signal intensity in DW-MRI. Patients were divided into groups according to presence/absence of SECI (+ SECI vs. - SECI, respectively). The clinical and angiographic characteristics were analyzed and independent predictors were evaluated. Of the 197 patients, SECI occurred in 20 patients (10.2%) after diagnostic CAG. Age, female gender, frequency of underlying atrial fibrillation, extent of coronary disease, and fluoroscopic time during diagnostic CAG were not different between the + SECI and - SECI groups. Left ventricular ejection fraction was significantly lower in the + SECI group than in the - SECI group (45.9 ± 8.5% vs. 51.4 ± 13.1%, p=0.014) and performance rate of internal mammary artery (IMA) angiography was significantly higher in the + SECI group compared with the - SECI group (85% vs. 37.2%, p<0.001). By multivariate analysis, performing IMA angiography was the only predictor of SECI (OR=14.642; 95% CI=3.201 to 66.980, p=0.001). The incidence of SECI after diagnostic CAG was not infrequent. Diagnostic CAG with IMA angiography may increase the risk of SECI. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Attention Deficit Hyperactivity Disorder in Children With Sickle Cell Disease Referred for an Evaluation.

PubMed

Acquazzino, Melissa A; Miller, Meghan; Myrvik, Matthew; Newby, Robert; Scott, John Paul

2017-07-01

Neuropsychological deficits, including difficulties with attention, are well described in children with sickle cell disease (SCD). Very little is known about attention deficit hyperactivity disorder (ADHD) in children with SCD. The objective of this study was to determine the proportion of ADHD in children with SCD referred for neuropsychological evaluation. This prospective, cross-sectional study included patients (age, 4 to 18 y) with SCD and completion of a neuropsychological evaluation between December 2013 and March 2016. Patients were referred for neuropsychological evaluation because of concern regarding school performance, development, and/or behavior. The diagnosis of ADHD was made by a neuropsychologist on the basis of the diagnostic criteria in the Diagnostic Statistical Manual-Fourth or Fifth Editions. ADHD medication usage rate was obtained by medical record review. Of the 89 patients with SCD referred for neuropsychological evaluation, 25% (95% confidence interval, 16%-35%) met diagnostic criteria for ADHD. Only 21% of the patients with SCD and ADHD were prescribed an ADHD medication. Our study supports routine ADHD screening in children with SCD who have poor school performance or behavioral concerns. Despite the benefits of pharmacologic treatment, the majority of patients with SCD and ADHD did not receive a medication for management of their ADHD.

Evidence of the preferential use of disease prototypes over case exemplars among early year one medical students prior to and following diagnostic training.

PubMed

Papa, Frank J; Li, Feiming

2015-12-01

Two core dual processing theory (DPT) System I constructs (Exemplars and Prototypes) were used to: 1) formulate a training exercise designed to improve diagnostic performance in year one medical students, and 2) explore whether any observed performance improvements were associated with preferential use of exemplars or prototypes. With IRB approval, 117 year one medical students participated in an acute chest pain diagnostic training exercise. A pre- and post-training test containing the same 27 case vignettes was used to determine if the subjects' diagnostic performance improved via training in both exemplars and prototypes. Exemplar and Prototype theory was also used to generate a unique typicality estimate for each case vignette. Because these estimates produce different performance predictions, differences in the subjects' observed performance would make it possible to infer whether subjects were preferentially using Exemplars or Prototypes. Pre- vs. post-training comparison revealed a significant performance improvement; t=14.04, p<0.001, Cohen's d=1.32. Pre-training, paired t-testing demonstrated that performance against the most typical vignettes>mid typical vignettes: t=4.94, p<0.001; and mid typical>least typical: t=5.16, p<0.001. Post-training, paired t-testing again demonstrated that performance against the most typical vignettes>mid typical: t=2.94, p<0.01; and mid typical>least typical: t=6.64, p<0.001. These findings are more consistent with the performance predictions generated via Prototype theory than Exemplar theory. DPT is useful in designing and evaluating the utility of new approaches to diagnostic training, and, investigating the cognitive factors driving diagnostic capabilities among early medical students.

Alpha 2 LASSO Data Bundles

DOE Data Explorer

Gustafson, William Jr; Vogelmann, Andrew; Endo, Satoshi; Toto, Tami; Xiao, Heng; Li, Zhijin; Cheng, Xiaoping; Kim, Jinwon; Krishna, Bhargavi

2015-08-31

The Alpha 2 release is the second release from the LASSO Pilot Phase that builds upon the Alpha 1 release. Alpha 2 contains additional diagnostics in the data bundles and focuses on cases from spring-summer 2016. A data bundle is a unified package consisting of LASSO LES input and output, observations, evaluation diagnostics, and model skill scores. LES input include model configuration information and forcing data. LES output includes profile statistics and full domain fields of cloud and environmental variables. Model evaluation data consists of LES output and ARM observations co-registered on the same grid and sampling frequency. Model performance is quantified by skill scores and diagnostics in terms of cloud and environmental variables.

Genetic Evaluation of Short Stature

PubMed Central

Rosenfeld, Ron G.

2014-01-01

Context: Genetics plays a major role in determining an individual's height. Although there are many monogenic disorders that lead to perturbations in growth and result in short stature, there is still no consensus as to the role that genetic diagnostics should play in the evaluation of a child with short stature. Evidence Acquisition: A search of PubMed was performed, focusing on the genetic diagnosis of short stature as well as on specific diagnostic subgroups included in this article. Consensus guidelines were reviewed. Evidence Synthesis: There are a multitude of rare genetic causes of severe short stature. There is no high-quality evidence to define the optimal approach to the genetic evaluation of short stature. We review genetic etiologies of a number of diagnostic subgroups and propose an algorithm for genetic testing based on these subgroups. Conclusion: Advances in genomic technologies are revolutionizing the diagnostic approach to short stature. Endocrinologists must become facile with the use of genetic testing in order to identify the various monogenic disorders that present with short stature. PMID:24915122

Comparison of diagnostic performance between single- and multiphasic contrast-enhanced abdominopelvic computed tomography in patients admitted to the emergency department with abdominal pain: potential radiation dose reduction.

PubMed

Hwang, Shin Hye; You, Je Sung; Song, Mi Kyong; Choi, Jin-Young; Kim, Myeong-Jin; Chung, Yong Eun

2015-04-01

To evaluate feasibility of radiation dose reduction by optimal phase selection of computed tomography (CT) in patients who visited the emergency department (ED) for abdominal pain. We included 253 patients who visited the ED for abdominal pain. They underwent multiphasic CT including precontrast, late arterial phase (LAP), and hepatic venous phase (HVP). Three image sets (HVP, precontrast + HVP, and precontrast + LAP + HVP) were reviewed. Two reviewers determined the most appropriate diagnosis with five-point confidence scale. Diagnostic performances were compared among image sets by weighted-least-squares method or DeLong's method. Linear mixed model was used to assess changes of diagnostic confidence and radiation dose. There was no difference in diagnostic performance among three image sets, although diagnostic confidence level was significantly improved after review of triphasic images compared with both HVP images only or HVP with precontrast images (confidence scale, 4.64 ± 0.05, 4.66 ± 0.05, and 4.76 ± 0.04 in the order of the sets; overall P = 0.0008). Similar trends were observed in the subgroup analysis for diagnosis of pelvic inflammatory disease and cholecystitis. There is no difference between HVP-CT alone and multiphasic CT for the diagnosis of causes of abdominal pain in patients admitted to the ED without prior chronic disease or neoplasia. • There was no difference in diagnostic performance of HVP CT and multiphasic CT. • The diagnostic confidence level was improved after review of the LAP images. • HVP CT can achieve diagnostic performance similar to that of multiphasic CT, while minimizing radiation.

Diagnostic performance of major depression disorder case-finding instruments used among mothers of young children in the United States: A systematic review.

PubMed

Owora, Arthur H; Carabin, Hélène; Reese, Jessica; Garwe, Tabitha

2016-09-01

Growing recognition of the interrelated negative outcomes associated with major depression disorder (MDD) among mothers and their children has led to renewed public health interest in the early identification and treatment of maternal MDD. Healthcare providers, however, remain unsure of the validity of existing case-finding instruments. We conducted a systematic review to identify the most valid maternal MDD case-finding instrument used in the United States. We identified articles reporting the sensitivity and specificity of MDD case-finding instruments based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) by systematically searching through three electronic bibliographic databases, PubMed, PsycINFO, and EMBASE, from 1994 to 2014. Study eligibility and quality were evaluated using the Standards for the Reporting of Diagnostic Accuracy studies and Quality Assessment of Diagnostic Accuracy Studies guidelines respectively. Overall, we retrieved 996 unduplicated articles and selected 74 for full-text review. Of these, 14 articles examining 21 different instruments were included in the systematic review. The 10 item Edinburgh Postnatal Depression Scale and Postpartum Depression Screening Scale had the most stable (lowest variation) and highest diagnostic performance during the antepartum and postpartum periods (sensitivity range: 0.63-0.94 and 0.67-0.95; specificity range: 0.83-0.98 and 0.68-0.97 respectively). Greater variation in diagnostic performance was observed among studies with higher MDD prevalence. Factors that explain greater variation in instrument diagnostic performance in study populations with higher MDD prevalence were not examined. Findings suggest that the diagnostic performance of maternal MDD case-finding instruments is peripartum period-specific. Published by Elsevier B.V.

A study to evaluate the efficacy of image-guided core biopsy in the diagnosis and management of lymphoma--results in 103 biopsies.

PubMed

Vandervelde, C; Kamani, T; Varghese, A; Ramesar, K; Grace, R; Howlett, D C

2008-04-01

The reason for this study was to evaluate the ability of image-guided core biopsy to replace surgical excision by providing sufficient diagnostic and treatment information. All consecutive image-guided core biopsies in patients with a final diagnosis of lymphoma over a 6-year period at our institution were collected retrospectively. Case notes and pathology reports were reviewed and the diagnostic techniques used were recorded. Pathology reports were graded according to their diagnostic completeness and their ability to provide treatment information. Out of a total of 328 instances of lymphoma, 103 image-guided core biopsies were performed in 96 patients. In 78% of these, the diagnostic information obtained from the biopsy provided a fully graded and subtyped diagnosis of lymphoma with sufficient information to initiate therapy. In the head and neck 67% of core biopsies were fully diagnostic for treatment purposes compared to 91% in the thorax, abdomen and pelvis. Image-guided core biopsy has a number of cost and safety advantages over surgical excision biopsy and in suitable cases it can obviate the need for surgery in cases of suspected lymphoma. This is especially relevant for elderly patients and those with poor performance status.

The IHS diagnostic X-ray equipment radiation protection program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knapp, A.; Byrns, G.; Suleiman, O.

The Indian Health Service (IHS) operates or contracts with Tribal groups to operate 50 hospitals and approximately 165 primary ambulatory care centers. These facilities contain approximately 275 medical and 800 dental diagnostic x-ray machines. IHS environmental health personnel in collaboration with the Food and Drug Administration's (FDA) Center for Devices and Radiological Health (CDRH) developed a diagnostic x-ray protection program including standard survey procedures and menu-driven calculations software. Important features of the program include the evaluation of equipment performance collection of average patient entrance skin exposure (ESE) measurements for selected procedures, and quality assurance. The ESE data, collected using themore » National Evaluation of X-ray Trends (NEXT) protocol, will be presented. The IHS Diagnostic X-ray Radiation Protection Program is dynamic and is adapting to changes in technology and workload.« less

Modular biowaste monitoring system

NASA Technical Reports Server (NTRS)

Fogal, G. L.

1975-01-01

The objective of the Modular Biowaste Monitoring System Program was to generate and evaluate hardware for supporting shuttle life science experimental and diagnostic programs. An initial conceptual design effort established requirements and defined an overall modular system for the collection, measurement, sampling and storage of urine and feces biowastes. This conceptual design effort was followed by the design, fabrication and performance evaluation of a flight prototype model urine collection, volume measurement and sampling capability. No operational or performance deficiencies were uncovered as a result of the performance evaluation tests.

Diagnostic Group Differences in Parent and Teacher Ratings on the BRIEF and Conners' Scales

ERIC Educational Resources Information Center

Sullivan, Jeremy R.; Riccio, Cynthia A.

2007-01-01

Objective: Behavioral rating scales are common instruments used in evaluations of ADHD and executive function. It is important to explore how different diagnostic groups perform on these measures, as this information can be used to provide criterion-related validity evidence for the measures. Method: Data from 92 children and adolescents were used…

Investigation of Missing Responses in Implementation of Cognitive Diagnostic Models

ERIC Educational Resources Information Center

Dai, Shenghai

2017-01-01

This dissertation is aimed at investigating the impact of missing data and evaluating the performance of five selected methods for handling missing responses in the implementation of Cognitive Diagnostic Models (CDMs). The five methods are: a) treating missing data as incorrect (IN), b) person mean imputation (PM), c) two-way imputation (TW), d)…

European Multicenter Study on Analytical Performance of Veris HIV-1 Assay.

PubMed

Braun, Patrick; Delgado, Rafael; Drago, Monica; Fanti, Diana; Fleury, Hervé; Hofmann, Jörg; Izopet, Jacques; Kalus, Ulrich; Lombardi, Alessandra; Marcos, Maria Angeles; Mileto, Davide; Sauné, Karine; O'Shea, Siobhan; Pérez-Rivilla, Alfredo; Ramble, John; Trimoulet, Pascale; Vila, Jordi; Whittaker, Duncan; Artus, Alain; Rhodes, Daniel W

2017-07-01

The analytical performance of the Veris HIV-1 assay for use on the new, fully automated Beckman Coulter DxN Veris molecular diagnostics system was evaluated at 10 European virology laboratories. The precision, analytical sensitivity, performance with negative samples, linearity, and performance with HIV-1 groups/subtypes were evaluated. The precision for the 1-ml assay showed a standard deviation (SD) of 0.14 log 10 copies/ml or less and a coefficient of variation (CV) of ≤6.1% for each level tested. The 0.175-ml assay showed an SD of 0.17 log 10 copies/ml or less and a CV of ≤5.2% for each level tested. The analytical sensitivities determined by probit analysis were 19.3 copies/ml for the 1-ml assay and 126 copies/ml for the 0.175-ml assay. The performance with 1,357 negative samples demonstrated 99.2% with not detected results. Linearity using patient samples was shown from 1.54 to 6.93 log 10 copies/ml. The assay performed well, detecting and showing linearity with all HIV-1 genotypes tested. The Veris HIV-1 assay demonstrated analytical performance comparable to that of currently marketed HIV-1 assays. (DxN Veris products are Conformité Européenne [CE]-marked in vitro diagnostic products. The DxN Veris product line has not been submitted to the U.S. FDA and is not available in the U.S. market. The DxN Veris molecular diagnostics system is also known as the Veris MDx molecular diagnostics system and the Veris MDx system.). Copyright © 2017 American Society for Microbiology.

The Diagnostic Performance of Stool DNA Testing for Colorectal Cancer: A Systematic Review and Meta-Analysis.

PubMed

Zhai, Rong-Lin; Xu, Fei; Zhang, Pei; Zhang, Wan-Li; Wang, Hui; Wang, Ji-Liang; Cai, Kai-Lin; Long, Yue-Ping; Lu, Xiao-Ming; Tao, Kai-Xiong; Wang, Guo-Bin

2016-02-01

This meta-analysis was designed to evaluate the diagnostic performance of stool DNA testing for colorectal cancer (CRC) and compare the performance between single-gene and multiple-gene tests.MEDLINE, Cochrane, EMBASE databases were searched using keywords colorectal cancers, stool/fecal, sensitivity, specificity, DNA, and screening. Sensitivity analysis, quality assessments, and performance bias were performed for the included studies.Fifty-three studies were included in the analysis with a total sample size of 7524 patients. The studies were heterogeneous with regard to the genes being analyzed for fecal genetic biomarkers of CRC, as well as the laboratory methods being used for each assay. The sensitivity of the different assays ranged from 2% to 100% and the specificity ranged from 81% to 100%. The meta-analysis found that the pooled sensitivities for single- and multigene assays were 48.0% and 77.8%, respectively, while the pooled specificities were 97.0% and 92.7%. Receiver operator curves and diagnostic odds ratios showed no significant difference between both tests with regard to sensitivity or specificity.This meta-analysis revealed that using assays that evaluated multiple genes compared with single-gene assays did not increase the sensitivity or specificity of stool DNA testing in detecting CRC.

Development, Evaluation, and Integration of a Quantitative Reverse-Transcription Polymerase Chain Reaction Diagnostic Test for Ebola Virus on a Molecular Diagnostics Platform.

PubMed

Cnops, Lieselotte; Van den Eede, Peter; Pettitt, James; Heyndrickx, Leo; De Smet, Birgit; Coppens, Sandra; Andries, Ilse; Pattery, Theresa; Van Hove, Luc; Meersseman, Geert; Van Den Herrewegen, Sari; Vergauwe, Nicolas; Thijs, Rein; Jahrling, Peter B; Nauwelaers, David; Ariën, Kevin K

2016-10-15

 The 2013-2016 Ebola epidemic in West Africa resulted in accelerated development of rapid diagnostic tests for emergency outbreak preparedness. We describe the development and evaluation of the Idylla™ prototype Ebola virus test, a fully automated sample-to-result molecular diagnostic test for rapid detection of Zaire ebolavirus (EBOV) and Sudan ebolavirus (SUDV).  The Idylla™ prototype Ebola virus test can simultaneously detect EBOV and SUDV in 200 µL of whole blood. The sample is directly added to a disposable cartridge containing all reagents for sample preparation, RNA extraction, and amplification by reverse-transcription polymerase chain reaction analysis. The performance was evaluated with a variety of sample types, including synthetic constructs and whole blood samples from healthy volunteers spiked with viral RNA, inactivated virus, and infectious virus.  The 95% limits of detection for EBOV and SUDV were 465 plaque-forming units (PFU)/mL (1010 copies/mL) and 324 PFU/mL (8204 copies/mL), respectively. In silico and in vitro analyses demonstrated 100% correct reactivity for EBOV and SUDV and no cross-reactivity with relevant pathogens. The diagnostic sensitivity was 97.4% (for EBOV) and 91.7% (for SUDV), the specificity was 100%, and the diagnostic accuracy was 95.9%.  The Idylla™ prototype Ebola virus test is a fast, safe, easy-to-use, and near-patient test that meets the performance criteria to detect EBOV in patients with suspected Ebola. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

National Performance Benchmarks for Modern Diagnostic Digital Mammography: Update from the Breast Cancer Surveillance Consortium.

PubMed

Sprague, Brian L; Arao, Robert F; Miglioretti, Diana L; Henderson, Louise M; Buist, Diana S M; Onega, Tracy; Rauscher, Garth H; Lee, Janie M; Tosteson, Anna N A; Kerlikowske, Karla; Lehman, Constance D

2017-04-01

Purpose To establish contemporary performance benchmarks for diagnostic digital mammography with use of recent data from the Breast Cancer Surveillance Consortium (BCSC). Materials and Methods Institutional review board approval was obtained for active or passive consenting processes or to obtain a waiver of consent to enroll participants, link data, and perform analyses. Data were obtained from six BCSC registries (418 radiologists, 92 radiology facilities). Mammogram indication and assessments were prospectively collected for women undergoing diagnostic digital mammography and linked with cancer diagnoses from state cancer registries. The study included 401 548 examinations conducted from 2007 to 2013 in 265 360 women. Results Overall diagnostic performance measures were as follows: cancer detection rate, 34.7 per 1000 (95% confidence interval [CI]: 34.1, 35.2); abnormal interpretation rate, 12.6% (95% CI: 12.5%, 12.7%); positive predictive value (PPV) of a biopsy recommendation (PPV 2 ), 27.5% (95% CI: 27.1%, 27.9%); PPV of biopsies performed (PPV 3 ), 30.4% (95% CI: 29.9%, 30.9%); false-negative rate, 4.8 per 1000 (95% CI: 4.6, 5.0); sensitivity, 87.8% (95% CI: 87.3%, 88.4%); and specificity, 90.5% (95% CI: 90.4%, 90.6%). Among cancers detected, 63.4% were stage 0 or 1 cancers, 45.6% were minimal cancers, the mean size of invasive cancers was 21.2 mm, and 69.6% of invasive cancers were node negative. Performance metrics varied widely across diagnostic indications, with cancer detection rate (64.5 per 1000) and abnormal interpretation rate (18.7%) highest for diagnostic mammograms obtained to evaluate a breast problem with a lump. Compared with performance during the screen-film mammography era, diagnostic digital performance showed increased abnormal interpretation and cancer detection rates and decreasing PPVs, with less than 70% of radiologists within acceptable ranges for PPV 2 and PPV 3 . Conclusion These performance measures can serve as national benchmarks that may help transform the marked variation in radiologists' diagnostic performance into targeted quality improvement efforts. © RSNA, 2017 Online supplemental material is available for this article.

An Evaluation of the Performance Diagnostic Checklist-Human Services (PDC-HS) Across Domains.

PubMed

Wilder, David A; Lipschultz, Joshua; Gehrman, Chana

2018-06-01

The Performance Diagnostic Checklist-Human Services (PDC-HS) is an informant-based tool designed to assess the environmental variables that contribute to poor employee performance in human service settings. Although the PDC-HS has been shown to effectively identify variables contributing to problematic performance, interventions based on only two of the four PDC-HS domains have been evaluated to date. In addition, the extent to which PDC-HS-indicated interventions are more effective than nonindicated interventions for two domains remains unclear. In the current study, we administered the PDC-HS to supervisors to assess the variables contributing to infrequent teaching of verbal operants and use of a timer by therapists at a center-based autism treatment program. Each of the four PDC-HS domains was identified as contributing to poor performance for at least one therapist. We then evaluated PDC-HS-indicated interventions for each domain. In addition, to assess the predictive validity of the tool, we evaluated various nonindicated interventions prior to implementing a PDC-HS-indicated intervention for two of the four domains. Results suggest that the PDC-HS-indicated interventions were effective across all four domains and were more effective than the nonindicated interventions for the two domains for which they were evaluated. Results are discussed in terms of the utility of the PDC-HS to identify appropriate interventions to manage therapist performance in human service settings.

Reduced-cost Chlamydia trachomatis-specific multiplex real-time PCR diagnostic assay evaluated for ocular swabs and use by trachoma research programmes.

PubMed

Butcher, Robert; Houghton, Jo; Derrick, Tamsyn; Ramadhani, Athumani; Herrera, Beatriz; Last, Anna R; Massae, Patrick A; Burton, Matthew J; Holland, Martin J; Roberts, Chrissy H

2017-08-01

Trachoma, caused by the intracellular bacterium Chlamydia trachomatis (Ct), is the leading infectious cause of preventable blindness. Many commercial platforms are available that provide highly sensitive and specific detection of Ct DNA. However, the majority of these commercial platforms are inaccessible for population-level surveys in resource-limited settings typical to trachoma control programmes. We developed two low-cost quantitative PCR (qPCR) tests for Ct using readily available reagents on standard real-time thermocyclers. Each multiplex qPCR test targets one genomic and one plasmid Ct target in addition to an endogenous positive control for Homo sapiens DNA. The quantitative performance of the qPCR assays in clinical samples was determined by comparison to a previously evaluated droplet digital PCR (ddPCR) test. The diagnostic performance of the qPCR assays were evaluated against a commercial assay (artus C. trachomatis Plus RG PCR, Qiagen) using molecular diagnostics quality control standards and clinical samples. We examined the yield of Ct DNA prepared from five different DNA extraction kits and a cold chain-free dry-sample preservation method using swabs spiked with fixed concentrations of human and Ct DNA. The qPCR assay was highly reproducible (Ct plasmid and genomic targets mean total coefficients of variance 41.5% and 48.3%, respectively). The assay detected 8/8 core specimens upon testing of a quality control panel and performed well in comparison to commercially marketed comparator test (sensitivity and specificity>90%). Optimal extraction and sample preservation methods for research applications were identified. We describe a pipeline from collection to diagnosis providing the most efficient sample preservation and extraction with significant per test cost savings over a commercial qPCR diagnostic assay. The assay and its evaluation should allow control programs wishing to conduct independent research within the context of trachoma control, access to an affordable test with defined performance characteristics. Copyright © 2017. Published by Elsevier B.V.

Articular cartilage grading of the knee: diagnostic performance of fat-suppressed 3D volume isotropic turbo spin-echo acquisition (VISTA) compared with 3D T1 high-resolution isovolumetric examination (THRIVE).

PubMed

Lee, Young Han; Hahn, Seok; Lim, Daekeon; Suh, Jin-Suck

2017-02-01

Background Conventionally, two-dimensional (2D) fast spin-echo (FSE) sequences have been widely used for clinical cartilage imaging as well as gradient (GRE) sequences. Recently, three-dimensional (3D) volumetric magnetic resonance imaging (MRI) has been introduced with one 3D volumetric scan, and this is replacing slice-by-slice 2D MR scans. Purpose To evaluate the image quality and diagnostic performance of two 3D sequences for abnormalities of knee cartilage: fat-suppressed (FS) FSE-based 3D volume isotropic turbo spin-echo acquisition (VISTA) and GRE-based 3D T1 high-resolution isovolumetric examination (THRIVE). Material and Methods The institutional review board approved the protocol of this retrospective review. This study enrolled 40 patients (41 knees) with arthroscopically confirmed abnormalities of cartilage. All patients underwent isovoxel 3D-VISTA and 3D-THRIVE MR sequences on 3T MRI. We assessed the cartilage grade on the two 3D sequences using arthroscopy as a gold standard. Inter-observer agreement for each technique was evaluated with the intraclass correlation coefficient (ICC). Differences in the area under the curve (AUC) were compared between the 3D-THRIVE and 3D-VISTA. Results Although inter-observer agreement for both sequences was excellent, the inter-observer agreement for 3D-VISTA was higher than for 3D-THRIVE for cartilage grading in all regions of the knee. There was no significant difference in the diagnostic performance ( P > 0.05) between the two sequences for detecting cartilage grade. Conclusion FSE-based 3D-VISTA images had good diagnostic performance that was comparable to GRE-based 3D-THRIVE images in the evaluation of knee cartilage, and can be used in routine knee MR protocols for the evaluation of cartilage.

Evaluation of interobserver variability and diagnostic performance of developed MRI-based radiological scoring system for invasive placenta previa.

PubMed

Ueno, Yoshiko; Maeda, Tetsuo; Tanaka, Utaru; Tanimura, Kenji; Kitajima, Kazuhiro; Suenaga, Yuko; Takahashi, Satoru; Yamada, Hideto; Sugimura, Kazuro

2016-09-01

To evaluate the interobserver variability and diagnostic performance of a developed magnetic resonance imaging (MRI)-based scoring system for invasive placenta previa. Prenatal MR images of 70 women were retrospectively evaluated, 18 of whom were diagnosed with invasive placenta. The six MR features (dark band on T2 -weighted images, intraplacental abnormal vascularity, placental bulge, heterogeneous placenta, myometrial thinning, and placental protrusion sign) were scored on 5-point Likert scale separately, and the cumulative radiological score (CRS) was defined as the sum of each score. Two more experienced radiologists (readers A and B) and two less experienced residents (readers C and D) calculated the CRS. Interobserver variability was assessed by measuring the intraclass correlation coefficient. Diagnostic performance was evaluated by means of receiver operating characteristic (ROC) analysis. Interobserver variability for CRS was excellent for the more experienced radiologists (0.85), and good for all readers (0.72) and the less experienced residents (0.66). The area under the ROC curve (Az) and accuracy (Acc) for CRS were significantly higher or equivalent to those of other MR features for all readers (Az and Acc for reader A; CRS, 0.92, 91.4%; intraplacental T2 dark band, 0.83, P = 0.009, 81.4%, P = 0.03; intraplacental abnormal vascularity, 0.9, P = 0.3, 90.0%, P = 1.00; placental bulge, 0.81, P = 0.0008, 80.0%, P = 0.02; heterogeneous placenta, 0.85, P = 0.11, 74.3%, P = 0.002; myometrial thinning, 0.84, P = 0.06, 60.0%, P < 0.0001; placental protrusion sign, 0.81, P = 0.01, 81.4%, P = 0.26). This developed MRI-based scoring system demonstrated excellent or good interobserver variability, and good diagnostic performance for invasive placenta previa. J. Magn. Reson. Imaging 2016;44:573-583. © 2016 International Society for Magnetic Resonance in Medicine.

History and Evolution of the Barium Swallow for Evaluation of the Pharynx and Esophagus.

PubMed

Levine, Marc S; Rubesin, Stephen E

2017-02-01

This article reviews the history of the barium swallow from its early role in radiology to its current status as an important diagnostic test in modern radiology practice. Though a variety of diagnostic procedures can be performed to evaluate patients with dysphagia or other pharyngeal or esophageal symptoms, the barium study has evolved into a readily available, non-invasive, and cost-effective technique that can facilitate the selection of additional diagnostic tests and guide decisions about medical, endoscopic, or surgical management. This article focuses on the evolution of fluoroscopic equipment, radiography, and contrast media for evaluating the pharynx and esophagus, the importance of understanding pharyngoesophageal relationships, and major advances that have occurred in the radiologic diagnosis of select esophageal diseases, including gastroesophageal reflux disease, infectious esophagitis, eosinophilic esophagitis, esophageal carcinoma, and esophageal motility disorders.

Quantitative polymerase chain reaction (PCR) for detection of aquatic animal pathogens in a diagnostic laboratory setting

USGS Publications Warehouse

Purcell, Maureen K.; Getchell, Rodman G.; McClure, Carol A.; Weber, S.E.; Garver, Kyle A.

2011-01-01

Real-time, or quantitative, polymerase chain reaction (qPCR) is quickly supplanting other molecular methods for detecting the nucleic acids of human and other animal pathogens owing to the speed and robustness of the technology. As the aquatic animal health community moves toward implementing national diagnostic testing schemes, it will need to evaluate how qPCR technology should be employed. This review outlines the basic principles of qPCR technology, considerations for assay development, standards and controls, assay performance, diagnostic validation, implementation in the diagnostic laboratory, and quality assurance and control measures. These factors are fundamental for ensuring the validity of qPCR assay results obtained in the diagnostic laboratory setting.

Determinants of Practice Patterns and Quality Gaps in Lung Cancer Staging and Diagnosis

PubMed Central

Niu, Jiangong; Elting, Linda S.; Buchholz, Thomas A.; Giordano, Sharon H.

2014-01-01

Background: Guidelines recommend mediastinal lymph node sampling as the first invasive diagnostic procedure in patients with suspected lung cancer with mediastinal lymphadenopathy without distant metastases. Methods: Patients were a retrospective cohort of 15,316 patients with lung cancer with regional spread without metastatic disease in the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) or Texas Cancer Registry Medicare-linked databases. Patients were categorized based on the sequencing of invasive diagnostic tests performed: (1) evaluation consistent with guidelines, mediastinal sampling done first; (2) evaluation inconsistent with guidelines, non-small cell lung cancer (NSCLC) present, mediastinal sampling performed but not as part of the first invasive test; (3) evaluation inconsistent with guidelines, NSCLC present, mediastinal sampling never done; and (4) evaluation inconsistent with guidelines, small cell lung cancer. The primary outcome was whether guideline-consistent care was delivered. Secondary outcomes included whether patients with NSCLC ever had mediastinal sampling and use of transbronchial needle aspiration (TBNA) among pulmonologists. Results: Only 21% of patients had a diagnostic evaluation consistent with guidelines. Only 56% of patients with NSCLC had mediastinal sampling prior to treatment. There was significant regional variability in guideline-consistent care (range, 12%-29%). Guideline-consistent care was associated with lower patient age, metropolitan areas, and if the physician ordering or performing the test was male, trained in the United States, had seen more patients with lung cancer, and was a pulmonologist or thoracic surgeon who had graduated more recently. More recent pulmonary graduates were also more likely to perform TBNA (P < .001). Conclusions: Guideline-consistent care varied regionally and was associated with physician-level factors, suggesting that a lack of effective physician training may be contributing to the quality gaps observed. PMID:24202651

Development of an Adaptable Display and Diagnostic System for the Evaluation of Tropical Cyclone Forecasts

NASA Astrophysics Data System (ADS)

Kucera, P. A.; Burek, T.; Halley-Gotway, J.

2015-12-01

NCAR's Joint Numerical Testbed Program (JNTP) focuses on the evaluation of experimental forecasts of tropical cyclones (TCs) with the goal of developing new research tools and diagnostic evaluation methods that can be transitioned to operations. Recent activities include the development of new TC forecast verification methods and the development of an adaptable TC display and diagnostic system. The next generation display and diagnostic system is being developed to support evaluation needs of the U.S. National Hurricane Center (NHC) and broader TC research community. The new hurricane display and diagnostic capabilities allow forecasters and research scientists to more deeply examine the performance of operational and experimental models. The system is built upon modern and flexible technology that includes OpenLayers Mapping tools that are platform independent. The forecast track and intensity along with associated observed track information are stored in an efficient MySQL database. The system provides easy-to-use interactive display system, and provides diagnostic tools to examine forecast track stratified by intensity. Consensus forecasts can be computed and displayed interactively. The system is designed to display information for both real-time and for historical TC cyclones. The display configurations are easily adaptable to meet the needs of the end-user preferences. Ongoing enhancements include improving capabilities for stratification and evaluation of historical best tracks, development and implementation of additional methods to stratify and compute consensus hurricane track and intensity forecasts, and improved graphical display tools. The display is also being enhanced to incorporate gridded forecast, satellite, and sea surface temperature fields. The presentation will provide an overview of the display and diagnostic system development and demonstration of the current capabilities.

The clinical performance evaluation of novel protein chips for eleven biomarkers detection and the diagnostic model study.

PubMed

Luo, Yuan; Zhu, Xu; Zhang, Pengjun; Shen, Qian; Wang, Zi; Wen, Xinyu; Wang, Ling; Gao, Jing; Dong, Jin; Yang, Caie; Wu, Tangming; Zhu, Zheng; Tian, Yaping

2015-01-01

We aimed to develop and validate two novel protein chips, which are based on microarray chemiluminescence immunoassay and can simultaneously detected 11 biomarkers, and then to evaluate their clinical diagnostic value by comparing with the traditional methods. Protein chips were evaluated for limit of detection, specificity, common interferences, linearity, precision and accuracy. 11 biomarkers were simultaneously detected by traditional methods and protein chips in 3683 samples, which included 1723 cancer patients, 1798 benign diseases patients and 162 healthy controls. After assay validation, protein chips demonstrated high sensitivity, high specificity, good linearity, low imprecision and were free of common interferences. Compared with the traditional methods, protein chips have good correlation in the detection of all the 13 kinds of biomarkers (r≥0.935, P<0.001). For specific cancer detection, there were no statistically significant differences between the traditional method and novel protein chips, except that male protein chip showed significantly better diagnostic value on NSE detection (P=0.004) but significantly worse value on pro-GRP detection (P=0.012), female chip showed significantly better diagnostic value on pro-GRP detection (P=0.005). Furthermore, both male and female multivariate diagnostic models had significantly better diagnostic value than single detection of PGI, PG II, pro-GRP, NSE and CA125 (P<0.05). In addition, male models had significantly better diagnostic value than single CA199 and free-PSA (P<0.05), while female models observed significantly better diagnostic value than single CA724 and β-HCG (P<0.05). For total disease or cancer detection, the AUC of multivariate logistic regression for the male and female disease detection was 0.981 (95% CI: 0.975-0.987) and 0.836 (95% CI: 0.798-0.874), respectively. While, that for total cancer detection was 0.691 (95% CI: 0.666-0.717) and 0.753 (95% CI: 0.731-0.775), respectively. The new designed protein chips are simple, multiplex and reliable clinical assays and the multi-parameter diagnostic models based on them could significantly improve their clinical performance.

The clinical performance evaluation of novel protein chips for eleven biomarkers detection and the diagnostic model study

PubMed Central

Luo, Yuan; Zhu, Xu; Zhang, Pengjun; Shen, Qian; Wang, Zi; Wen, Xinyu; Wang, Ling; Gao, Jing; Dong, Jin; Yang, Caie; Wu, Tangming; Zhu, Zheng; Tian, Yaping

2015-01-01

We aimed to develop and validate two novel protein chips, which are based on microarray chemiluminescence immunoassay and can simultaneously detected 11 biomarkers, and then to evaluate their clinical diagnostic value by comparing with the traditional methods. Protein chips were evaluated for limit of detection, specificity, common interferences, linearity, precision and accuracy. 11 biomarkers were simultaneously detected by traditional methods and protein chips in 3683 samples, which included 1723 cancer patients, 1798 benign diseases patients and 162 healthy controls. After assay validation, protein chips demonstrated high sensitivity, high specificity, good linearity, low imprecision and were free of common interferences. Compared with the traditional methods, protein chips have good correlation in the detection of all the 13 kinds of biomarkers (r≥0.935, P<0.001). For specific cancer detection, there were no statistically significant differences between the traditional method and novel protein chips, except that male protein chip showed significantly better diagnostic value on NSE detection (P=0.004) but significantly worse value on pro-GRP detection (P=0.012), female chip showed significantly better diagnostic value on pro-GRP detection (P=0.005). Furthermore, both male and female multivariate diagnostic models had significantly better diagnostic value than single detection of PGI, PG II, pro-GRP, NSE and CA125 (P<0.05). In addition, male models had significantly better diagnostic value than single CA199 and free-PSA (P<0.05), while female models observed significantly better diagnostic value than single CA724 and β-HCG (P<0.05). For total disease or cancer detection, the AUC of multivariate logistic regression for the male and female disease detection was 0.981 (95% CI: 0.975-0.987) and 0.836 (95% CI: 0.798-0.874), respectively. While, that for total cancer detection was 0.691 (95% CI: 0.666-0.717) and 0.753 (95% CI: 0.731-0.775), respectively. The new designed protein chips are simple, multiplex and reliable clinical assays and the multi-parameter diagnostic models based on them could significantly improve their clinical performance. PMID:26884957

Computerized screening devices and performance assessment: development of a policy towards automation. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

PubMed

Bartels, P H; Bibbo, M; Hutchinson, M L; Gahm, T; Grohs, H K; Gwi-Mak, E; Kaufman, E A; Kaufman, R H; Knight, B K; Koss, L G; Magruder, L E; Mango, L J; McCallum, S M; Melamed, M R; Peebles, A; Richart, R M; Robinowitz, M; Rosenthal, D L; Sauer, T; Schenck, U; Tanaka, N; Topalidis, T; Verhest, A P; Wertlake, P T; Wilbur, D C

1998-01-01

The extension of automation to the diagnostic assessment of clinical materials raises issues of professional responsibility, on the part of both the medical professional and designer of the device. The International Academy of Cytology (IAC) and other professional cytology societies should develop a policy towards automation in the diagnostic assessment of clinical cytologic materials. The following summarizes the discussion of the initial position statement at the International Expert Conference on Diagnostic Cytology Towards the 21st Century, Hawaii, June 1997. 1. The professional in charge of a clinical cytopathology laboratory continues to bear the ultimate medical responsibility for diagnostic decisions made at the facility, whether automated devices are involved or not. 2. The introduction of automated procedures into clinical cytology should under no circumstances lead to a lowering of standards of performance. A prime objective of any guidelines should be to ensure that an automated procedure, in principle, does not expose any patient to new risks, nor should it increase already-existing, inherent risks. 3. Automated devices should provide capabilities for the medical professional to conduct periodic tests of the appropriate performance of the device. 4. Supervisory personnel should continue visual quality control screening of a certain percentage of slides dismissed at primary screening as within normal limits (WNL), even when automated procedures are employed in the laboratory. 5. Specifications for the design of primary screening devices for the detection of cervical cancer issued by the IAC in 1984 were reaffirmed. 6. The setting of numeric performance criteria is the proper charge of regulatory agencies, which also have the power of enforcement. 7. Human expert verification of results represents the "gold standard" at this time. Performance characteristics of computerized cytology devices should be determined by adherence to defined and well-considered protocols. Manufacturers should not claim a new standard of care; this is the responsibility of the medical community and professional groups. 8. Cytology professionals should support the development of procedures that bring about an improvement in diagnostic decision making. Advances in technology should be adopted if they can help solve problems in clinical cytology. The introduction of automated procedures into diagnostic decision making should take place strictly under the supervision and with the active participation and critical evaluation by the professional cytology community. Guidelines should be developed for the communication of technical information about the performance of automated screening devices by the IAC to governmental agencies and national societies. Also, guidelines are necessary for the official communication of IAC concerns to industry, medicolegal entities and the media. Procedures and guidelines for the evaluation of studies pertaining to the performance of automated devices, performance metrics and definitions for evaluation criteria should be established.

The Arthroscopic Surgical Skill Evaluation Tool (ASSET)

PubMed Central

Koehler, Ryan J.; Amsdell, Simon; Arendt, Elizabeth A; Bisson, Leslie J; Braman, Jonathan P; Butler, Aaron; Cosgarea, Andrew J; Harner, Christopher D; Garrett, William E; Olson, Tyson; Warme, Winston J.; Nicandri, Gregg T.

2014-01-01

Background Surgeries employing arthroscopic techniques are among the most commonly performed in orthopaedic clinical practice however, valid and reliable methods of assessing the arthroscopic skill of orthopaedic surgeons are lacking. Hypothesis The Arthroscopic Surgery Skill Evaluation Tool (ASSET) will demonstrate content validity, concurrent criterion-oriented validity, and reliability, when used to assess the technical ability of surgeons performing diagnostic knee arthroscopy on cadaveric specimens. Study Design Cross-sectional study; Level of evidence, 3 Methods Content validity was determined by a group of seven experts using a Delphi process. Intra-articular performance of a right and left diagnostic knee arthroscopy was recorded for twenty-eight residents and two sports medicine fellowship trained attending surgeons. Subject performance was assessed by two blinded raters using the ASSET. Concurrent criterion-oriented validity, inter-rater reliability, and test-retest reliability were evaluated. Results Content validity: The content development group identified 8 arthroscopic skill domains to evaluate using the ASSET. Concurrent criterion-oriented validity: Significant differences in total ASSET score (p<0.05) between novice, intermediate, and advanced experience groups were identified. Inter-rater reliability: The ASSET scores assigned by each rater were strongly correlated (r=0.91, p <0.01) and the intra-class correlation coefficient between raters for the total ASSET score was 0.90. Test-retest reliability: there was a significant correlation between ASSET scores for both procedures attempted by each individual (r = 0.79, p<0.01). Conclusion The ASSET appears to be a useful, valid, and reliable method for assessing surgeon performance of diagnostic knee arthroscopy in cadaveric specimens. Studies are ongoing to determine its generalizability to other procedures as well as to the live OR and other simulated environments. PMID:23548808

Prospective comparison among transient elastography, supersonic shear imaging, and ARFI imaging for predicting fibrosis in nonalcoholic fatty liver disease

PubMed Central

Joo, Sae Kyung; Woo, Hyunsik; Lee, Dong Hyeon; Jung, Yong Jin; Kim, Byeong Gwan; Lee, Kook Lae

2017-01-01

The diagnostic performance of supersonic shear imaging (SSI) in comparison with those of transient elastography (TE) and acoustic radiation force impulse imaging (ARFI) for staging fibrosis in nonalcoholic fatty liver disease (NAFLD) patients has not been fully assessed, especially in Asian populations with relatively lean NAFLD compared to white populations. Thus, we focused on comparing the diagnostic performances of TE, ARFI, and SSI for staging fibrosis in a head-to-head manner, and identifying the clinical, anthropometric, biochemical, and histological features which might affect liver stiffness measurement (LSM) in our prospective biopsy-proven NAFLD cohort. In this study, ninety-four patients with biopsy-proven NAFLD were included prospectively. Liver stiffness was measured using TE, SSI, and ARFI within 1 month of liver biopsy. The diagnostic performance for staging fibrosis was assessed using receiver operating characteristic (ROC) analysis. Anthropometric data were evaluated as covariates influencing LSM by regression analyses. Liver stiffness correlated with fibrosis stage (p < 0.05); the area under the ROC curve of TE (kPa), SSI (kPa), and ARFI (m/s) were as follows: 0.757, 0.759, and 0.657 for significant fibrosis and 0.870, 0.809, and 0.873 for advanced fibrosis. Anthropometric traits were significant confounders affecting SSI, while serum liver injury markers significantly confounded TE and ARFI. In conclusion, the LSM methods had similar diagnostic performance for staging fibrosis in patients with NAFLD. Pre-LSM anthropometric evaluation may help predict the reliability of SSI. PMID:29176844

Diagnostic Accuracy of MRI-guided Percutaneous Transthoracic Needle Biopsy of Solitary Pulmonary Nodules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Shangang, E-mail: 1198685580@qq.com; Li, Chengli, E-mail: chenglilichina@yeah.net; Yu, Xuejuan, E-mail: yuxuejuan2011@126.com

2015-04-15

ObjectiveThe purpose of our study was to evaluate the diagnostic accuracy of MRI-guided percutaneous transthoracic needle biopsy (PTNB) of solitary pulmonary nodules (SPNs).MethodsRetrospective review of 69 patients who underwent MR-guided PTNB of SPNs was performed. Each case was reviewed for complications. The final diagnosis was established by surgical pathology of the nodule or clinical and imaging follow-up. Pneumothorax rate and diagnostic accuracy were compared between two groups according to nodule diameter (≤2 vs. >2 cm) using χ{sup 2} chest and Fisher’s exact test, respectively.ResultsThe success rate of single puncture was 95.6 %. Twelve (17.4 %) patients had pneumothorax, with 1 (1.4 %) requiring chestmore » tube insertion. Mild hemoptysis occurred in 7 (7.2 %) patients. All of the sample material was sufficient for histological diagnostic evaluation. Pathological analysis of biopsy specimens showed 46 malignant, 22 benign, and 1 nondiagnostic nodule. The final diagnoses were 49 malignant nodules and 20 benign nodules basing on postoperative histopathology and clinical follow-up data. One nondiagnostic sample was excluded from calculating diagnostic performance. A sensitivity, specificity, accuracy, positive predictive value, and negative predictive value in diagnosing SPNs were 95.8, 100, 97.0, 100, and 90.9 %, respectively. Pneumothorax rate, diagnostic sensitivity, and accuracy were not significantly different between the two groups (P > 0.05).ConclusionsMRI-guided PTNB is safe, feasible, and high accurate diagnostic technique for pathologic diagnosis of pulmonary nodules.« less

[Implementation of cytology images classification--the Bethesda 2001 System--in a group of screened women from Podlaskie region--effect evaluation].

PubMed

Zbroch, Tomasz; Knapp, Paweł Grzegorz; Knapp, Piotr Andrzej

2007-09-01

Increasing knowledge concerning carcinogenesis within cervical epithelium has forced us to make continues modifications of cytology classification of the cervical smears. Eventually, new descriptions of the submicroscopic cytomorphological abnormalities have enabled the implementation of Bethesda System which was meant to take place of the former Papanicolaou classification although temporarily both are sometimes used simultaneously. The aim of this study was to compare results of these two classification systems in the aspect of diagnostic accuracy verified by further tests of the diagnostic algorithm for the cervical lesion evaluation. The study was conducted in the group of women selected from general population, the criteria being the place of living and cervical cancer age risk group, in the consecutive periods of mass screening in Podlaski region. The performed diagnostic tests have been based on the commonly used algorithm, as well as identical laboratory and methodological conditions. Performed assessment revealed comparable diagnostic accuracy of both analyzing classifications, verified by histological examination, although with marked higher specificity for dysplastic lesions with decreased number of HSIL results and increased diagnosis of LSILs. Higher number of performed colposcopies and biopsies were an additional consequence of TBS classification. Results based on Bethesda System made it possible to find the sources and reasons of abnormalities with much greater precision, which enabled causing agent treatment. Two evaluated cytology classification systems, although not much different, depicted higher potential of TBS and better, more effective communication between cytology laboratory and gynecologist, making reasonable implementation of The Bethesda System in the daily cytology screening work.

Financial Statement Analysis for Colleges and Universities.

ERIC Educational Resources Information Center

Woelfel, Charles J.

1987-01-01

Presents ratio analysis of financial statements as a tool applicable for use by nonprofit institutions for evaluation of financial and operational performance of an institution. It can be used as a screening, forecasting, diagnostic, and evaluative tool for administration and governance. (MD)

A Framework to Debug Diagnostic Matrices

NASA Technical Reports Server (NTRS)

Kodal, Anuradha; Robinson, Peter; Patterson-Hine, Ann

2013-01-01

Diagnostics is an important concept in system health and monitoring of space operations. Many of the existing diagnostic algorithms utilize system knowledge in the form of diagnostic matrix (D-matrix, also popularly known as diagnostic dictionary, fault signature matrix or reachability matrix) gleaned from physical models. But, sometimes, this may not be coherent to obtain high diagnostic performance. In such a case, it is important to modify this D-matrix based on knowledge obtained from other sources such as time-series data stream (simulated or maintenance data) within the context of a framework that includes the diagnostic/inference algorithm. A systematic and sequential update procedure, diagnostic modeling evaluator (DME) is proposed to modify D-matrix and wrapper logic considering least expensive solution first. This iterative procedure includes conditions ranging from modifying 0s and 1s in the matrix, or adding/removing the rows (failure sources) columns (tests). We will experiment this framework on datasets from DX challenge 2009.

Factors Associated with the Performance and Cost-Effectiveness of Using Lymphatic Filariasis Transmission Assessment Surveys for Monitoring Soil-Transmitted Helminths: A Case Study in Kenya

PubMed Central

Smith, Jennifer L.; Sturrock, Hugh J. W.; Assefa, Liya; Nikolay, Birgit; Njenga, Sammy M.; Kihara, Jimmy; Mwandawiro, Charles S.; Brooker, Simon J.

2015-01-01

Transmission assessment surveys (TAS) for lymphatic filariasis have been proposed as a platform to assess the impact of mass drug administration (MDA) on soil-transmitted helminths (STHs). This study used computer simulation and field data from pre- and post-MDA settings across Kenya to evaluate the performance and cost-effectiveness of the TAS design for STH assessment compared with alternative survey designs. Variations in the TAS design and different sample sizes and diagnostic methods were also evaluated. The district-level TAS design correctly classified more districts compared with standard STH designs in pre-MDA settings. Aggregating districts into larger evaluation units in a TAS design decreased performance, whereas age group sampled and sample size had minimal impact. The low diagnostic sensitivity of Kato-Katz and mini-FLOTAC methods was found to increase misclassification. We recommend using a district-level TAS among children 8–10 years of age to assess STH but suggest that key consideration is given to evaluation unit size. PMID:25487730

Joint confidence region estimation for area under ROC curve and Youden index.

PubMed

Yin, Jingjing; Tian, Lili

2014-03-15

In the field of diagnostic studies, the area under the ROC curve (AUC) serves as an overall measure of a biomarker/diagnostic test's accuracy. Youden index, defined as the overall correct classification rate minus one at the optimal cut-off point, is another popular index. For continuous biomarkers of binary disease status, although researchers mainly evaluate the diagnostic accuracy using AUC, for the purpose of making diagnosis, Youden index provides an important and direct measure of the diagnostic accuracy at the optimal threshold and hence should be taken into consideration in addition to AUC. Furthermore, AUC and Youden index are generally correlated. In this paper, we initiate the idea of evaluating diagnostic accuracy based on AUC and Youden index simultaneously. As the first step toward this direction, this paper only focuses on the confidence region estimation of AUC and Youden index for a single marker. We present both parametric and non-parametric approaches for estimating joint confidence region of AUC and Youden index. We carry out extensive simulation study to evaluate the performance of the proposed methods. In the end, we apply the proposed methods to a real data set. Copyright © 2013 John Wiley & Sons, Ltd.

QUADAS and STARD: evaluating the quality of diagnostic accuracy studies.

PubMed

Oliveira, Maria Regina Fernandes de; Gomes, Almério de Castro; Toscano, Cristiana Maria

2011-04-01

To compare the performance of two approaches, one based on the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) and another on the Standards for Reporting Studies of Diagnostic Accuracy (STARD), in evaluating the quality of studies validating the OptiMal® rapid malaria diagnostic test. Articles validating the rapid test published until 2007 were searched in the Medline/PubMed database. This search retrieved 13 articles. A combination of 12 QUADAS criteria and three STARD criteria were compared with the 12 QUADAS criteria alone. Articles that fulfilled at least 50% of QUADAS criteria were considered as regular to good quality. Of the 13 articles retrieved, 12 fulfilled at least 50% of QUADAS criteria, and only two fulfilled the STARD/QUADAS criteria combined. Considering the two criteria combination (> 6 QUADAS and > 3 STARD), two studies (15.4%) showed good methodological quality. The articles selection using the proposed combination resulted in two to eight articles, depending on the number of items assumed as cutoff point. The STARD/QUADAS combination has the potential to provide greater rigor when evaluating the quality of studies validating malaria diagnostic tests, given that it incorporates relevant information not contemplated in the QUADAS criteria alone.

Testing Expert-Based versus Student-Based Cognitive Models for a Grade 3 Diagnostic Mathematics Assessment

ERIC Educational Resources Information Center

Roduta Roberts, Mary; Alves, Cecilia B.; Chu, Man-Wai; Thompson, Margaret; Bahry, Louise M.; Gotzmann, Andrea

2014-01-01

The purpose of this study was to evaluate the adequacy of three cognitive models, one developed by content experts and two generated from student verbal reports for explaining examinee performance on a grade 3 diagnostic mathematics test. For this study, the items were developed to directly measure the attributes in the cognitive model. The…

Performance of the new automated Abbott RealTime MTB assay for rapid detection of Mycobacterium tuberculosis complex in respiratory specimens.

PubMed

Chen, J H K; She, K K K; Kwong, T-C; Wong, O-Y; Siu, G K H; Leung, C-C; Chang, K-C; Tam, C-M; Ho, P-L; Cheng, V C C; Yuen, K-Y; Yam, W-C

2015-09-01

The automated high-throughput Abbott RealTime MTB real-time PCR assay has been recently launched for Mycobacterium tuberculosis complex (MTBC) clinical diagnosis. This study would like to evaluate its performance. We first compared its diagnostic performance with the Roche Cobas TaqMan MTB assay on 214 clinical respiratory specimens. Prospective analysis of a total 520 specimens was then performed to further evaluate the Abbott assay. The Abbott assay showed a lower limit of detection at 22.5 AFB/ml, which was more sensitive than the Cobas assay (167.5 AFB/ml). The two assays demonstrated a significant difference in diagnostic performance (McNemar's test; P = 0.0034), in which the Abbott assay presented significantly higher area under curve (AUC) than the Cobas assay (1.000 vs 0.880; P = 0.0002). The Abbott assay demonstrated extremely low PCR inhibition on clinical respiratory specimens. The automated Abbott assay required only very short manual handling time (0.5 h), which could help to improve the laboratory management. In the prospective analysis, the overall estimates for sensitivity and specificity of the Abbott assay were both 100 % among smear-positive specimens, whereas the smear-negative specimens were 96.7 and 96.1 %, respectively. No cross-reactivity with non-tuberculosis mycobacterial species was observed. The superiority in sensitivity of the Abbott assay for detecting MTBC in smear-negative specimens could further minimize the risk in MTBC false-negative detection. The new Abbott RealTime MTB assay has good diagnostic performance which can be a useful diagnostic tool for rapid MTBC detection in clinical laboratories.

Communicating with Faculty Using a Diagnostic Performance Appraisal Process.

ERIC Educational Resources Information Center

Gibson, Ken

In spite of the many teacher evaluation models available and the extensive research on performance appraisal, few community colleges have effectively come to terms with this difficult task. Many administrators prefer to avoid the interpersonal conflict and the possible legal ramifications of performance appraisal. However, in times of limited…

Historical patterns in the types of procedures performed and radiation safety practices used in nuclear medicine from 1945–2009

PubMed Central

Van Dyke, Miriam E.; Drozdovitch, Vladimir; Doody, Michele M.; Lim, Hyeyeun; Bolus, Norman E.; Simon, Steven L.; Alexander, Bruce H.; Kitahara, Cari M.

2016-01-01

We evaluated historical patterns in the types of procedures performed in diagnostic and therapeutic nuclear medicine and the associated radiation safety practices used from 1945–2009 in a sample of U.S. radiologic technologists. In 2013–2014, 4,406 participants from the U.S. Radiologic Technologists (USRT) Study who previously reported working with medical radionuclides completed a detailed survey inquiring about the performance of 23 diagnostic and therapeutic radionuclide procedures and the use of radiation safety practices when performing radionuclide procedure-related tasks during five time periods: 1945–1964, 1965–1979, 1980–1989, 1990–1999, and 2000–2009. We observed an overall increase in the proportion of technologists who performed specific diagnostic or therapeutic procedures across the five time periods. Between 1945–1964 and 2000–2009, the median frequency of diagnostic procedures performed substantially increased (5 per week to 30 per week), attributable mainly to an increasing frequency of cardiac and non-brain PET scans, while the median frequency of therapeutic procedures performed modestly decreased (from 4 per month to 3 per month). We also observed a notable increase in the use of most radiation safety practices from 1945–1964 to 2000–2009 (e.g., use of lead-shielded vials during diagnostic radiopharmaceutical preparation increased from 56 to 96%), although lead apron use dramatically decreased (e.g., during diagnostic imaging procedures, from 81 to 7%). These data describe historical practices in nuclear medicine and can be used to support studies of health risks in nuclear medicine technologists. PMID:27218293

Use of 3×2 tables with an intention to diagnose approach to assess clinical performance of diagnostic tests: meta-analytical evaluation of coronary CT angiography studies

PubMed Central

Schuetz, Georg M; Schlattmann, Peter

2012-01-01

Objective To determine whether a 3×2 table, using an intention to diagnose approach, is better than the “classic” 2×2 table at handling transparent reporting and non-evaluable results, when assessing the accuracy of a diagnostic test. Design Based on a systematic search for diagnostic accuracy studies of coronary computed tomography (CT) angiography, full texts of relevant studies were evaluated to determine whether they could calculate an alternative 3×2 table. To quantify an overall effect, we pooled diagnostic accuracy values according to a meta-analytical approach. Data sources Medline (via PubMed), Embase (via Ovid), and ISI Web of Science electronic databases. Eligibility criteria Prospective English or German language studies comparing coronary CT with conventional coronary angiography in all patients and providing sufficient data for a patient level analysis. Results 120 studies (10 287 patients) were eligible. Studies varied greatly in their approaches to handling non-evaluable findings. We found 26 studies (including 2298 patients) that allowed us to calculate both 2×2 tables and 3×2 tables. Using a bivariate random effects model, we compared the 2×2 table with the 3×2 table, and found significant differences for pooled sensitivity (98.2 (95% confidence interval 96.7 to 99.1) v 92.7 (88.5 to 95.3)), area under the curve (0.99 (0.98 to 1.00) v 0.93 (0.91 to 0.95)), positive likelihood ratio (9.1 (6.2 to 13.3) v 4.4 (3.3 to 6.0)), and negative likelihood ratio (0.02 (0.01 to 0.04) v 0.09 (0.06 to 0.15); (P<0.05)). Conclusion Parameters for diagnostic performance significantly decrease if non-evaluable results are included by a 3×2 table for analysis (intention to diagnose approach). This approach provides a more realistic picture of the clinical potential of diagnostic tests. PMID:23097549

Detection of infragenual arterial disease using noncontrast-enhanced MR angiography in patients with diabetes

PubMed Central

Liu, Xin; Zhang, Na; Fan, Zhaoyang; Feng, Fei; Yang, Qi; Zheng, Hairong; Liu, Pengcheng; Li, Debiao

2013-01-01

Purpose To evaluate the diagnostic performance of a newly developed noncontrast-enhanced MR angiography (NCE-MRA) technique using flow-sensitive dephasing (FSD) prepared steady-state free precession (SSFP) for detecting calf arterial disease in patients with diabetes. Materials and Methods Forty-five patients with diabetes who underwent routine CE-MRA of lower extremities were recruited for NCE-MRA at the calf on a 1.5T MR system. Image quality evaluated on a four-point scale and diagnostic performance for detecting more than 50% arterial stenosis were statistically analyzed, using CE-MRA as the standard of reference. Results A total of 264 calf arterial segments were obtained in the 45 patients with 88 legs. The percentage of diagnostic arterial segments was all 98% for NCE- and CE-MRA. The image quality, SNR, CNR was 3.3, 177, 138 and 3.5, 103, 99 for NCE-MRA and CE-MRA respectively. The average sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of NCE-MRA were 97%, 96%, 90%, 99%, and 96%, respectively on a per-segment basis and 90%, 84%, 82%, 91%, and 87%, respectively on a per-patients basis. Conclusion The NCE-MRA technique demonstrates adequate image quality in the delineation of calf arteries and consistent diagnostic performance for detecting significant stenosis with CE-MRA in patients with diabetes. PMID:24925770

Diagnostic performance of instantaneous wave-free ratio for the evaluation of coronary stenosis severity confirmed by fractional flow reserve: A PRISMA-compliant meta-analysis of randomized studies.

PubMed

Man, Wanrong; Hu, Jianqiang; Zhao, Zhijing; Zhang, Mingming; Wang, Tingting; Lin, Jie; Duan, Yu; Wang, Ling; Wang, Haichang; Sun, Dongdong; Li, Yan

2016-09-01

The instantaneous wave-free ratio (iFR) is a new vasodilator-free index of coronary stenosis severity. The aim of this meta-analysis is to assess the diagnostic performance of iFR for the evaluation of coronary stenosis severity with fractional flow reserve as standard reference. We searched PubMed, EMBASE, CENTRAL, ProQuest, Web of Science, and International Clinical Trials Registry Platform (ICTRP) for publications concerning the diagnostic value of iFR. We used a random-effects covariate to synthesize the available data of sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR). Overall test performance was summarized by the summary receiver operating characteristic curve (sROC) and the area under the curve (AUC). Eight studies with 1611 subjects were included in the meta-analysis. The pooled sensitivity, specificity, LR+, LR-, and DOR for iFR were respectively 73.3% (70.1-76.2%), 86.4% (84.3-88.3%), 5.71 (4.43-7.37), 0.29 (0.22-0.38), and 20.54 (16.11-26.20). The area under the summary receiver operating characteristic curves for iFR was 0.8786. No publication bias was identified. The available evidence suggests that iFR may be a new, simple, and promising technology for coronary stenosis physiological assessment.

Clinical Evaluation of a Loop-Mediated Amplification Kit for Diagnosis of Imported Malaria

PubMed Central

Polley, Spencer D.; González, Iveth J.; Mohamed, Deqa; Daly, Rosemarie; Bowers, Kathy; Watson, Julie; Mewse, Emma; Armstrong, Margaret; Gray, Christen; Perkins, Mark D.; Bell, David; Kanda, Hidetoshi; Tomita, Norihiro; Kubota, Yutaka; Mori, Yasuyoshi; Chiodini, Peter L.; Sutherland, Colin J.

2013-01-01

Background. Diagnosis of malaria relies on parasite detection by microscopy or antigen detection; both fail to detect low-density infections. New tests providing rapid, sensitive diagnosis with minimal need for training would enhance both malaria diagnosis and malaria control activities. We determined the diagnostic accuracy of a new loop-mediated amplification (LAMP) kit in febrile returned travelers. Methods. The kit was evaluated in sequential blood samples from returned travelers sent for pathogen testing to a specialist parasitology laboratory. Microscopy was performed, and then malaria LAMP was performed using Plasmodium genus and Plasmodium falciparum–specific tests in parallel. Nested polymerase chain reaction (PCR) was performed on all samples as the reference standard. Primary outcome measures for diagnostic accuracy were sensitivity and specificity of LAMP results, compared with those of nested PCR. Results. A total of 705 samples were tested in the primary analysis. Sensitivity and specificity were 98.4% and 98.1%, respectively, for the LAMP P. falciparum primers and 97.0% and 99.2%, respectively, for the Plasmodium genus primers. Post hoc repeat PCR analysis of all 15 tests with discrepant results resolved 4 results in favor of LAMP, suggesting that the primary analysis had underestimated diagnostic accuracy. Conclusions. Malaria LAMP had a diagnostic accuracy similar to that of nested PCR, with a greatly reduced time to result, and was superior to expert microscopy. PMID:23633403

Diagnostic Capability of Spectral Domain Optical Coherence Tomography for Glaucoma

PubMed Central

Wu, Huijuan; de Boer, Johannes F.; Chen, Teresa C.

2012-01-01

Purpose To determine the diagnostic capability of spectral domain optical coherence tomography (OCT) in glaucoma patients with visual field (VF) defects. Design Prospective, cross-sectional study. Methods Setting Participants were recruited from a university hospital clinic. Study Population One eye of 85 normal subjects and 61 glaucoma patients [with average VF mean deviation (MD) of -9.61 ± 8.76 dB] were randomly selected for the study. A subgroup of the glaucoma patients with early VF defects was calculated separately. Observation Procedures Spectralis OCT circular scans were performed to obtain peripapillary retinal nerve fiber layer (RNFL) thicknesses. The RNFL diagnostic parameters based on the normative database were used alone or in combination for identifying glaucomatous RNFL thinning. Main Outcome Measures To evaluate diagnostic performance, calculations included areas under the receiver operating characteristic curve (AROC), sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio. Results Overall RNFL thickness had the highest AROC value (0.952 for all patients, 0.895 for the early glaucoma subgroup). For all patients, the highest sensitivity (98.4%, CI 96.3-100%) was achieved by using two criteria: ≥1 RNFL sectors being abnormal at the < 5% level, and overall classification of borderline or outside normal limits, with specificities of 88.9% (CI 84.0-94.0%) and 87.1% (CI 81.6-92.5%) respectively for these two criteria. Conclusions Statistical parameters for evaluating the diagnostic performance of the Spectralis spectral domain OCT were good for early perimetric glaucoma and excellent for moderately-advanced perimetric glaucoma. PMID:22265147

Diagnostic value of FDG-PET/(CT) in children with fever of unknown origin and unexplained fever during immune suppression.

PubMed

Blokhuis, Gijsbert J; Bleeker-Rovers, Chantal P; Diender, Marije G; Oyen, Wim J G; Draaisma, Jos M Th; de Geus-Oei, Lioe-Fee

2014-10-01

Fever of unknown origin (FUO) and unexplained fever during immune suppression in children are challenging medical problems. The aim of this study is to investigate the diagnostic value of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and FDG-PET combined with computed tomography (FDG-PET/CT) in children with FUO and in children with unexplained fever during immune suppression. All FDG-PET/(CT) scans performed in the Radboud university medical center for the evaluation of FUO or unexplained fever during immune suppression in the last 10 years were reviewed. Results were compared with the final clinical diagnosis. FDG-PET/(CT) scans were performed in 31 children with FUO. A final diagnosis was established in 16 cases (52 %). Of the total number of scans, 32 % were clinically helpful. The sensitivity and specificity of FDG-PET/CT in these patients was 80 % and 78 %, respectively. FDG-PET/(CT) scans were performed in 12 children with unexplained fever during immune suppression. A final diagnosis was established in nine patients (75 %). Of the total number of these scans, 58 % were clinically helpful. The sensitivity and specificity of FDG-PET/CT in children with unexplained fever during immune suppression was 78 % and 67 %, respectively. FDG-PET/CT appears a valuable imaging technique in the evaluation of children with FUO and in the diagnostic process of children with unexplained fever during immune suppression. Prospective studies of FDG-PET/CT as part of a structured diagnostic protocol are warranted to assess the additional diagnostic value.

Emergency admissions due to swallowed foreign bodies in adults

PubMed Central

Erbil, Bülent; Karaca, Mehmet Ali; Aslaner, Mehmet Ali; İbrahimov, Zaur; Kunt, Mehmet Mahir; Akpinar, Erhan; Özmen, Mehmet Mahir

2013-01-01

AIM: To study a retrospective analysis of patients who presented to the emergency departments (ED) with complaints related to foreign body ingestions. METHODS: Patients older than 16 years of age who presented to the ED between January 1st and December 31st of 2010 with complaints related to swallowed foreign bodies were identified from electronic health records and patient charts. RESULTS: A total of 100 patients presented with a complaint of foreign body ingestion during the study period. Overall, an X-ray was performed on 75 patients, and a fiberoptic evaluation was performed on 45 patients. A foreign body was detected in 46 (46%) patients. The diagnostic yield of the X-ray was 27 (36%) out of 75 patients, while the diagnostic yield of the fiberoptic evaluations was 21 (47%) out of 45 patients. The detected foreign bodies were mostly located in the esophagus (17 out of 46 foreign bodies detected). When the types of ingested foreign bodies were evaluated, 52 (52%) patients reported ingesting food, and 19 (19%) patients reported swallowing pins. An X-ray was performed on 33 patients with accidental food ingestions but yielded a positive result in only two cases. In 12 out of 21 patients with accidental food ingestion who underwent fiberoptic evaluation, the foreign material was detected and removed. CONCLUSION: Plain radiography is helpful in the localization of radiopaque swollen foreign bodies, while fiberoptic methods are useful as both diagnostic and therapeutic tools, regardless of radiopacity. PMID:24151363

Emergency admissions due to swallowed foreign bodies in adults.

PubMed

Erbil, Bülent; Karaca, Mehmet Ali; Aslaner, Mehmet Ali; Ibrahimov, Zaur; Kunt, Mehmet Mahir; Akpinar, Erhan; Özmen, Mehmet Mahir

2013-10-14

To study a retrospective analysis of patients who presented to the emergency departments (ED) with complaints related to foreign body ingestions. Patients older than 16 years of age who presented to the ED between January 1(st) and December 31(st) of 2010 with complaints related to swallowed foreign bodies were identified from electronic health records and patient charts. A total of 100 patients presented with a complaint of foreign body ingestion during the study period. Overall, an X-ray was performed on 75 patients, and a fiberoptic evaluation was performed on 45 patients. A foreign body was detected in 46 (46%) patients. The diagnostic yield of the X-ray was 27 (36%) out of 75 patients, while the diagnostic yield of the fiberoptic evaluations was 21 (47%) out of 45 patients. The detected foreign bodies were mostly located in the esophagus (17 out of 46 foreign bodies detected). When the types of ingested foreign bodies were evaluated, 52 (52%) patients reported ingesting food, and 19 (19%) patients reported swallowing pins. An X-ray was performed on 33 patients with accidental food ingestions but yielded a positive result in only two cases. In 12 out of 21 patients with accidental food ingestion who underwent fiberoptic evaluation, the foreign material was detected and removed. Plain radiography is helpful in the localization of radiopaque swollen foreign bodies, while fiberoptic methods are useful as both diagnostic and therapeutic tools, regardless of radiopacity.

An Integrated Architecture for Aircraft Engine Performance Monitoring and Fault Diagnostics: Engine Test Results

NASA Technical Reports Server (NTRS)

Rinehart, Aidan W.; Simon, Donald L.

2015-01-01

This paper presents a model-based architecture for performance trend monitoring and gas path fault diagnostics designed for analyzing streaming transient aircraft engine measurement data. The technique analyzes residuals between sensed engine outputs and model predicted outputs for fault detection and isolation purposes. Diagnostic results from the application of the approach to test data acquired from an aircraft turbofan engine are presented. The approach is found to avoid false alarms when presented nominal fault-free data. Additionally, the approach is found to successfully detect and isolate gas path seeded-faults under steady-state operating scenarios although some fault misclassifications are noted during engine transients. Recommendations for follow-on maturation and evaluation of the technique are also presented.

An Integrated Architecture for Aircraft Engine Performance Monitoring and Fault Diagnostics: Engine Test Results

NASA Technical Reports Server (NTRS)

Rinehart, Aidan W.; Simon, Donald L.

2014-01-01

This paper presents a model-based architecture for performance trend monitoring and gas path fault diagnostics designed for analyzing streaming transient aircraft engine measurement data. The technique analyzes residuals between sensed engine outputs and model predicted outputs for fault detection and isolation purposes. Diagnostic results from the application of the approach to test data acquired from an aircraft turbofan engine are presented. The approach is found to avoid false alarms when presented nominal fault-free data. Additionally, the approach is found to successfully detect and isolate gas path seeded-faults under steady-state operating scenarios although some fault misclassifications are noted during engine transients. Recommendations for follow-on maturation and evaluation of the technique are also presented.

A global comparative evaluation of commercial immunochromatographic rapid diagnostic tests for visceral leishmaniasis.

PubMed

Cunningham, Jane; Hasker, Epco; Das, Pradeep; El Safi, Sayda; Goto, Hiro; Mondal, Dinesh; Mbuchi, Margaret; Mukhtar, Maowia; Rabello, Ana; Rijal, Suman; Sundar, Shyam; Wasunna, Monique; Adams, Emily; Menten, Joris; Peeling, Rosanna; Boelaert, Marleen

2012-11-15

Poor access to diagnosis stymies control of visceral leishmaniasis (VL). Antibody-detecting rapid diagnostic tests (RDTs) can be performed in peripheral health settings. However, there are many brands available and published reports of variable accuracy. Commercial VL RDTs containing bound rK39 or rKE16 antigen were evaluated using archived human sera from confirmed VL cases (n = 750) and endemic non-VL controls (n = 754) in the Indian subcontinent (ISC), Brazil, and East Africa to assess sensitivity and specificity with 95% confidence intervals. A subset of RDTs were also evaluated after 60 days' heat incubation (37°C, 45°C). Interlot and interobserver variability was assessed. All test brands performed well against ISC panels (sensitivity range, 92.8%-100%; specificity range, 96%-100%); however, sensitivity was lower against Brazil and East African panels (61.5%-91% and 36.8%-87.2%, respectively). Specificity was consistently > 95% in Brazil and ranged between 90.8% and 98% in East Africa. Performance of some products was adversely affected by high temperatures. Agreement between lots and readers was good to excellent (κ > 0.73-0.99). Diagnostic accuracy of VL RDTs varies between the major endemic regions. Many tests performed well and showed good heat stability in the ISC; however, reduced sensitivity against Brazilian and East African panels suggests that in these regions, used alone, several RDTs are inadequate for excluding a VL diagnosis. More research is needed to assess ease of use and to compare performance using whole blood instead of serum and in patients coinfected with human immunodeficiency virus.

Combining independent decisions increases diagnostic accuracy of reading lumbosacral radiographs and magnetic resonance imaging.

PubMed

Kurvers, Ralf H J M; de Zoete, Annemarie; Bachman, Shelby L; Algra, Paul R; Ostelo, Raymond

2018-01-01

Diagnosing the causes of low back pain is a challenging task, prone to errors. A novel approach to increase diagnostic accuracy in medical decision making is collective intelligence, which refers to the ability of groups to outperform individual decision makers in solving problems. We investigated whether combining the independent ratings of chiropractors, chiropractic radiologists and medical radiologists can improve diagnostic accuracy when interpreting diagnostic images of the lumbosacral spine. Evaluations were obtained from two previously published studies: study 1 consisted of 13 raters independently rating 300 lumbosacral radiographs; study 2 consisted of 14 raters independently rating 100 lumbosacral magnetic resonance images. In both studies, raters evaluated the presence of "abnormalities", which are indicators of a serious health risk and warrant immediate further examination. We combined independent decisions of raters using a majority rule which takes as final diagnosis the decision of the majority of the group. We compared the performance of the majority rule to the performance of single raters. Our results show that with increasing group size (i.e., increasing the number of independent decisions) both sensitivity and specificity increased in both data-sets, with groups consistently outperforming single raters. These results were found for radiographs and MR image reading alike. Our findings suggest that combining independent ratings can improve the accuracy of lumbosacral diagnostic image reading.

Evaluation performance of diagnostic methods of intestinal parasitosis in school age children in Ethiopia.

PubMed

Yimer, Mulat; Hailu, Tadesse; Mulu, Wondemagegn; Abera, Bayeh

2015-12-26

Although the sensitivity of Wet mount technique is questionable, it is the major diagnostic technique for routine diagnosis of intestinal parasitosis in Ethiopia. Therefore, the aim of this study was the evaluation performance of diagnostic methods of intestinal parasitosis in school age children in Ethiopia. A cross sectional study was conducted from May to June 2013. Single stool sample was processed for direct, Formol ether concentration (FEC) and Kato Katz methods. The sensitivity and negative predictive value (NPV) of diagnostic tests were calculated in terms of the "Gold" standard method (the combined result of the three methods altogether). A total of 422 school age children were participated in this study. The prevalence of intestinal parasites was high (74.6%) with Kato Katz technique. The sensitivity of Wet mount, FEC and Kato Katz tests against the Gold standard test was 48.9, 63.1 and 93.7%, respectively. Kato Katz technique revealed a better NPV 80.4 (80.1-80.6) as compared to the Wet mount (33.7%) and FEC techniques (41.3%). In this study, the Kato Katz technique outperformed the other two methods but the true values for sensitivity, specificity and diagnostic values are not known. Moreover, it is labor intensive and not easily accessible. Hence, it is preferable to use FEC technique to complement the Wet mount test.

Two Decades of WRF/CMAQ simulations over the continental United States: New approaches for performing dynamic model evaluation and determining confidence limits for ozone exceedances

EPA Science Inventory

Confidence in the application of models for forecasting and regulatory assessments is furthered by conducting four types of model evaluation: operational, dynamic, diagnostic, and probabilistic. Operational model evaluation alone does not reveal the confidence limits that can be ...

Diagnosis of Spinal Lesions Using Heuristic and Pharmacokinetic Parameters Measured by Dynamic Contrast-Enhanced MRI.

PubMed

Lang, Ning; Yuan, Huishu; Yu, Hon J; Su, Min-Ying

2017-07-01

This study aimed to evaluate the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in differentiation of four spinal lesions by using heuristic and pharmacokinetic parameters analyzed from DCE signal intensity time course. DCE-MRI of 62 subjects with confirmed myeloma (n = 9), metastatic cancer (n = 22), lymphoma (n = 7), and inflammatory tuberculosis (TB) (n = 24) in the spine were analyzed retrospectively. The region of interest was placed on strongly enhanced tissues. The DCE time course was categorized as the "wash-out," "plateau," or "persistent enhancement" pattern. The maximum enhancement, steepest wash-in enhancement, and wash-out slope using the signal intensity at 67 seconds after contrast injection as reference were measured. The Tofts 2-compartmental pharmacokinetic model was applied to obtain K trans and k ep . Pearson correlation between heuristic and pharmacokinetic parameters was evaluated, and receiver operating characteristic curve analysis was performed for pairwise group differentiation. The mean wash-out slope was -22% ± 10% for myeloma, 1% ± 0.4% for metastatic cancer, 3% ± 3% for lymphoma, and 7% ± 10% for TB, and it could significantly distinguish myeloma from metastasis (area under the curve [AUC] = 0.884), lymphoma (AUC = 1.0), and TB (AUC = 1.0) with P = .001, and distinguish metastasis from TB (AUC = 0.741) with P = .005. The k ep and wash-out slope were highly correlated (r = 0.92), and they showed a similar diagnostic performance. The K trans was significantly correlated with the maximum enhancement (r = 0.71) and the steepest wash-in enhancement (r = 0.85), but they had inferior diagnostic performance compared to the wash-out slope. DCE-MRI may provide additional diagnostic information, and a simple wash-out slope had the best diagnostic performance. The heuristic and pharmacokinetic parameters were highly correlated. Copyright © 2017. Published by Elsevier Inc.

Adaptive prospective ECG-triggered sequence coronary angiography in dual-source CT without heart rate control: Image quality and diagnostic performance.

PubMed

Pan, Chang-Jie; Qian, Nong; Wang, Tao; Tang, Xiao-Qiang; Xue, Yue-Jun

2013-02-01

The aim of this study was to evaluate the accuracy of using second generation dual-source CT (DSCT) to obtain high quality images and diagnostic performance and to reduce the radiation dose in adaptive prospective electrocardiography (ECG)-triggered sequence (CorAdSeq) CT coronary angiography (CTCA) without heart rate control. No prescan β-blockers were administered. Un-enhanced CT and CTCA with adaptive prospective CorAdSeq scanning without heart rate control were performed in 683 consecutive patients divided into two body mass index (BMI) groups: BMI <25 kg/m(2) (group A, n=412) and BMI ≥25 kg/m(2) (group B, n=271). The image quality and quantitative stenosis of all coronary segments with a diameter ≥1 mm were assessed. The mean heart rate (MHR), heart rate variability (HRV) and radiation dose values were recorded. In 426 cases, the diagnostic performance was evaluated using quantitative conventional coronary angiography as the reference standard. Diagnostic image quality was obtained in 98.5% of segments in group A and in 98.8% of segments in group B, with no significant differences between the groups. No correlations were observed between the image quality score and MHR or HRV (P=0.492, P=0.564, respectively). The effective radiation doses in groups A and B were 2.57±1.01 mSv and 6.36±1.88 mSv, respectively. The sensitivities and specificities of diagnosing coronary heart disease per patient were 99.6% and 97.8% in group A and 99.5% and 97.5% in group B, respectively (P>0.05). Adaptive prospective CorAdSeq scanning, without heart rate control, by second generation DSCT had a high image quality and diagnostic performance for coronary artery stenosis with lower radiation doses.

Mediators of Stereotype Threat Induced by Diagnostic Testing by Stereotype Relevant Out-Group Evaluators: The Roles of Evaluator's Racial Fairness and Support on Performance Outcome

ERIC Educational Resources Information Center

Wilburn, Grady Akile

2010-01-01

There is an abundance of research that examines the social-psychological phenomenon called stereotype threat. There is not, however, a conclusive understanding of the processes and mechanisms that operate within stereotype threat that produce reduced performance in a negative stereotype relevant area. This dissertation proposes that there are…

Statistical evaluation of vibration analysis techniques

NASA Technical Reports Server (NTRS)

Milner, G. Martin; Miller, Patrice S.

1987-01-01

An evaluation methodology is presented for a selection of candidate vibration analysis techniques applicable to machinery representative of the environmental control and life support system of advanced spacecraft; illustrative results are given. Attention is given to the statistical analysis of small sample experiments, the quantification of detection performance for diverse techniques through the computation of probability of detection versus probability of false alarm, and the quantification of diagnostic performance.

Atomic Resonance Radiation Energetics Investigation as a Diagnostic Method for Non-Equilibrium Hypervelocity Flows

NASA Technical Reports Server (NTRS)

Meyer, Scott A.; Bershader, Daniel; Sharma, Surendra P.; Deiwert, George S.

1996-01-01

Absorption measurements with a tunable vacuum ultraviolet light source have been proposed as a concentration diagnostic for atomic oxygen, and the viability of this technique is assessed in light of recent measurements. The instrumentation, as well as initial calibration measurements, have been reported previously. We report here additional calibration measurements performed to study the resonance broadening line shape for atomic oxygen. The application of this diagnostic is evaluated by considering the range of suitable test conditions and requirements, and by identifying issues that remain to be addressed.

Drug-device trials for infectious diseases: CDRH perspective.

PubMed

Meier, Kristen L; Gitterman, Steven

2011-05-01

Assessing the performance of new diagnostic tests for infectious diseases has traditionally focused on comparing the new assay against a reference standard such as culture. In this paper, we suggest that clinical trial designs with both a diagnostic and therapeutic component may be necessary to evaluate the safety and effectiveness of nonmicrobiologically based assays, with a specific emphasis on the test/marker-stratified design. General design challenges for trials of infectious diseases that simultaneously study both diagnostic and therapeutic components (eg, both devices and drugs) are also discussed.

Evaluation of virtual monoenergetic imaging algorithms for dual-energy carotid and intracerebral CT angiography: Effects on image quality, artefacts and diagnostic performance for the detection of stenosis.

PubMed

Leithner, Doris; Mahmoudi, Scherwin; Wichmann, Julian L; Martin, Simon S; Lenga, Lukas; Albrecht, Moritz H; Booz, Christian; Arendt, Christophe T; Beeres, Martin; D'Angelo, Tommaso; Bodelle, Boris; Vogl, Thomas J; Scholtz, Jan-Erik

2018-02-01

To investigate the impact of traditional (VMI) and noise-optimized virtual monoenergetic imaging (VMI+) algorithms on quantitative and qualitative image quality, and the assessment of stenosis in carotid and intracranial dual-energy CTA (DE-CTA). DE-CTA studies of 40 patients performed on a third-generation 192-slice dual-source CT scanner were included in this retrospective study. 120-kVp image-equivalent linearly-blended, VMI and VMI+ series were reconstructed. Quantitative analysis included evaluation of contrast-to-noise ratios (CNR) of the aorta, common carotid artery, internal carotid artery, middle cerebral artery, and basilar artery. VMI and VMI+ with highest CNR, and linearly-blended series were rated qualitatively. Three radiologists assessed artefacts and suitability for evaluation at shoulder height, carotid bifurcation, siphon, and intracranial using 5-point Likert scales. Detection and grading of stenosis were performed at carotid bifurcation and siphon. Highest CNR values were observed for 40-keV VMI+ compared to 65-keV VMI and linearly-blended images (P < 0.001). Artefacts were low in all qualitatively assessed series with excellent suitability for supraaortic artery evaluation at shoulder and bifurcation height. Suitability was significantly higher in VMI+ and VMI compared to linearly-blended images for intracranial and ICA assessment (P < 0.002). VMI and VMI+ showed excellent accordance for detection and grading of stenosis at carotid bifurcation and siphon with no differences in diagnostic performance. 40-keV VMI+ showed improved quantitative image quality compared to 65-keV VMI and linearly-blended series in supraaortic DE-CTA. VMI and VMI+ provided increased suitability for carotid and intracranial artery evaluation with excellent assessment of stenosis, but did not translate into increased diagnostic performance. Copyright © 2017 Elsevier B.V. All rights reserved.

Update on diagnostic value of breath test in gastrointestinal and liver diseases

PubMed Central

Siddiqui, Imran; Ahmed, Sibtain; Abid, Shahab

2016-01-01

In the field of gastroenterology, breath tests (BTs) are used intermittently as diagnostic tools that allow indirect, non-invasive and relatively less cumbersome evaluation of several disorders by simply quantifying the appearance in exhaled breath of a metabolite of a specific substrate administered. The aim of this review is to have an insight into the principles, methods of analysis and performance parameters of various hydrogen, methane and carbon BTs which are available for diagnosing gastrointestinal disorders such as Helicobacter pylori infection, small intestinal bacterial overgrowth, and carbohydrate malabsorption. Evaluation of gastric emptying is routinely performed by scintigraphy which is however, difficult to perform and not suitable for children and pregnant women, this review has abridged the 13C-octanoic acid test in comparison to scintigraphy and has emphasized on its working protocol and challenges. A new development such as electronic nose test is also highlighted. Moreover we have also explored the limitations and constraints restraining the wide use of these BT. We conclude that breath testing has an enormous potential to be used as a diagnostic modality. In addition it offers distinct advantages over the traditional invasive methods commonly employed. PMID:27574563

A novel approach for evaluating the performance of real time quantitative loop-mediated isothermal amplification-based methods.

PubMed

Nixon, Gavin J; Svenstrup, Helle F; Donald, Carol E; Carder, Caroline; Stephenson, Judith M; Morris-Jones, Stephen; Huggett, Jim F; Foy, Carole A

2014-12-01

Molecular diagnostic measurements are currently underpinned by the polymerase chain reaction (PCR). There are also a number of alternative nucleic acid amplification technologies, which unlike PCR, work at a single temperature. These 'isothermal' methods, reportedly offer potential advantages over PCR such as simplicity, speed and resistance to inhibitors and could also be used for quantitative molecular analysis. However there are currently limited mechanisms to evaluate their quantitative performance, which would assist assay development and study comparisons. This study uses a sexually transmitted infection diagnostic model in combination with an adapted metric termed isothermal doubling time (IDT), akin to PCR efficiency, to compare quantitative PCR and quantitative loop-mediated isothermal amplification (qLAMP) assays, and to quantify the impact of matrix interference. The performance metric described here facilitates the comparison of qLAMP assays that could assist assay development and validation activities.

Diagnostic Accuracy of Natriuretic Peptides for Heart Failure in Patients with Pleural Effusion: A Systematic Review and Updated Meta-Analysis

PubMed Central

Cheng, Juan-Juan; Zhao, Shi-Di; Gao, Ming-Zhu; Huang, Hong-Yu; Gu, Bing; Ma, Ping; Chen, Yan; Wang, Jun-Hong; Yang, Cheng-Jian; Yan, Zi-He

2015-01-01

Background Previous studies have reported that natriuretic peptides in the blood and pleural fluid (PF) are effective diagnostic markers for heart failure (HF). These natriuretic peptides include N-terminal pro-brain natriuretic peptide (NT-proBNP), brain natriuretic peptide (BNP), and midregion pro-atrial natriuretic peptide (MR-proANP). This systematic review and meta-analysis evaluates the diagnostic accuracy of blood and PF natriuretic peptides for HF in patients with pleural effusion. Methods PubMed and EMBASE databases were searched to identify articles published in English that investigated the diagnostic accuracy of BNP, NT-proBNP, and MR-proANP for HF. The last search was performed on 9 October 2014. The quality of the eligible studies was assessed using the revised Quality Assessment of Diagnostic Accuracy Studies tool. The diagnostic performance characteristics (sensitivity, specificity, and other measures of accuracy) were pooled and examined using a bivariate model. Results In total, 14 studies were included in the meta-analysis, including 12 studies reporting the diagnostic accuracy of PF NT-proBNP and 4 studies evaluating blood NT-proBNP. The summary estimates of PF NT-proBNP for HF had a diagnostic sensitivity of 0.94 (95% confidence interval [CI]: 0.90–0.96), specificity of 0.91 (95% CI: 0.86–0.95), positive likelihood ratio of 10.9 (95% CI: 6.4–18.6), negative likelihood ratio of 0.07 (95% CI: 0.04–0.12), and diagnostic odds ratio of 157 (95% CI: 57–430). The overall sensitivity of blood NT-proBNP for diagnosis of HF was 0.92 (95% CI: 0.86–0.95), with a specificity of 0.88 (95% CI: 0.77–0.94), positive likelihood ratio of 7.8 (95% CI: 3.7–16.3), negative likelihood ratio of 0.10 (95% CI: 0.06–0.16), and diagnostic odds ratio of 81 (95% CI: 27–241). The diagnostic accuracy of PF MR-proANP and blood and PF BNP was not analyzed due to the small number of related studies. Conclusions BNP, NT-proBNP, and MR-proANP, either in blood or PF, are effective tools for diagnosis of HF. Additional studies are needed to rigorously evaluate the diagnostic accuracy of PF and blood MR-proANP and BNP for the diagnosis of HF. PMID:26244664

Evaluation of a diagnostic flow chart applying medical thoracoscopy, adenosine deaminase and T-SPOT.TB in diagnosis of tuberculous pleural effusion.

PubMed

He, Y; Zhang, W; Huang, T; Wang, X; Wang, M

2015-10-01

To evaluate a diagnostic flow chart applying medical thoracoscoy (MT), adenosine deaminase (ADA) and T-SPOT.TB in diagnosis of tuberculous pleural effusion (TPE) at a high TB burden country. 136 patients with pleural effusion (PE) were enrolled and divided into TPE and Non-TPE group. MT (histology), PE ADA and T-SPOT.TB were conducted on all patients. ROC analysis was performed for the best cut-off value of PE ADA in detection of TPE. The diagnostic flow chart applying MT, ADA and T-SPOT.TB was evaluated for improving the limitations of each diagnostic method. ROC analysis showed that the best cut-off value of PE ADA was 30U/L. The sensitivity and specificity of these tests were calculated respectively to be: 71.4% (58.5%-81.6%) and 100% (95.4-100.0%) for MT, 92.9% (83.0-97.2%) and 68.8% (57.9-77.9%) for T-SPOT.TB, and 80.0% (69.6-88.1%) and 92.9% (82.7-98.0%) for PE ADA. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, positive predictive value and negative predictive value of the diagnostic flow chart were 96.4% (87.9-99.0%), 96.3% (89.6-98.7%), 25.714, 0.037, 97.4 and 94.9, respectively. The diagnostic flow chart applying MT, ADA and T-SPOT.TB is an accurate and rapid diagnostic method in detection of TPE.

Development of stimulation diagnostic technology. Annual report, May 1990--December 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warpinski, N.R.; Lorenz, J.C.

The objective of this project is to apply Sandia`s expertise and technology towards the development of stimulation diagnostic technology in the areas of in situ stress, natural fracturing, stimulation processes and instrumentation systems. Initial work has concentrated on experiment planning for a site where hydraulic fracturing could be evaluated and design models and fracture diagnostics could be validated and improved. Important issues have been defined and new diagnostics, such as inclinometers, identified. In the area of in situ stress, circumferential velocity analysis is proving to be a useful diagnostic for stress orientation. Natural fracture studies of the Frontier formation aremore » progressing; two fracture sets have been found and their relation to tectonic events have been hypothesized. Analyses of stimulation data have been performed for several sites, primarily for in situ stress information. Some new ideas in stimulation diagnostics have been proposed; these ideas may significantly improve fracture diagnostic capabilities.« less

Development of stimulation diagnostic technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warpinski, N.R.; Lorenz, J.C.

The objective of this project is to apply Sandia's expertise and technology towards the development of stimulation diagnostic technology in the areas of in situ stress, natural fracturing, stimulation processes and instrumentation systems. Initial work has concentrated on experiment planning for a site where hydraulic fracturing could be evaluated and design models and fracture diagnostics could be validated and improved. Important issues have been defined and new diagnostics, such as inclinometers, identified. In the area of in situ stress, circumferential velocity analysis is proving to be a useful diagnostic for stress orientation. Natural fracture studies of the Frontier formation aremore » progressing; two fracture sets have been found and their relation to tectonic events have been hypothesized. Analyses of stimulation data have been performed for several sites, primarily for in situ stress information. Some new ideas in stimulation diagnostics have been proposed; these ideas may significantly improve fracture diagnostic capabilities.« less

Comparative evaluation of fluorescent in situ hybridization and Giemsa microscopy with quantitative real-time PCR technique in detecting malaria parasites in a holoendemic region of Kenya.

PubMed

Osoga, Joseph; Waitumbi, John; Guyah, Bernard; Sande, James; Arima, Cornel; Ayaya, Michael; Moseti, Caroline; Morang'a, Collins; Wahome, Martin; Achilla, Rachel; Awinda, George; Nyakoe, Nancy; Wanja, Elizabeth

2017-07-24

Early and accurate diagnosis of malaria is important in treatment as well as in the clinical evaluation of drugs and vaccines. Evaluation of Giemsa-stained smears remains the gold standard for malaria diagnosis, although diagnostic errors and potential bias estimates of protective efficacy have been reported in practice. Plasmodium genus fluorescent in situ hybridization (P-Genus FISH) is a microscopy-based method that uses fluorescent labelled oligonucleotide probes targeted to pathogen specific ribosomal RNA fragments to detect malaria parasites in whole blood. This study sought to evaluate the diagnostic performance of P-Genus FISH alongside Giemsa microscopy compared to quantitative reverse transcription polymerase chain reaction (qRT-PCR) in a clinical setting. Five hundred study participants were recruited prospectively and screened for Plasmodium parasites by P-Genus FISH assay, and Giemsa microscopy. The microscopic methods were performed by two trained personnel and were blinded, and if the results were discordant a third reading was performed as a tie breaker. The diagnostic performance of both methods was evaluated against qRT-PCR as a more sensitive method. The number of Plasmodium positive cases was 26.8% by P-Genus FISH, 33.2% by Giemsa microscopy, and 51.2% by qRT-PCR. The three methods had 46.8% concordant results with 61 positive cases and 173 negative cases. Compared to qRT-PCR the sensitivity and specificity of P-Genus FISH assay was 29.3 and 75.8%, respectively, while microscopy had 58.2 and 93.0% respectively. Microscopy had a higher positive and negative predictive values (89.8 and 68.0% respectively) compared to P-Genus FISH (56.0 and 50.5%). In overall, microscopy had a good measure of agreement (76%, k = 0.51) compared to P-Genus FISH (52%, k = 0.05). The diagnostic performance of P-Genus FISH was shown to be inferior to Giemsa microscopy in the clinical samples. This hinders the possible application of the method in the field despite the many advantages of the method especially diagnosis of low parasite density infections. The P-Genus assay has great potential but application of the method in clinical setting would rely on extensive training of microscopist and continuous proficiency testing.

Evaluation of a 5-Marker Blood Test for Colorectal Cancer Early Detection in a Colorectal Cancer Screening Setting.

PubMed

Werner, Simone; Krause, Friedemann; Rolny, Vinzent; Strobl, Matthias; Morgenstern, David; Datz, Christian; Chen, Hongda; Brenner, Hermann

2016-04-01

In initial studies that included colorectal cancer patients undergoing diagnostic colonoscopy, we had identified a serum marker combination able to detect colorectal cancer with similar diagnostic performance as fecal immunochemical test (FIT). In this study, we aimed to validate the results in participants of a large colorectal cancer screening study conducted in the average-risk, asymptomatic screening population. We tested serum samples from 1,200 controls, 420 advanced adenoma patients, 4 carcinoma in situ patients, and 36 colorectal cancer patients with a 5-marker blood test [carcinoembryonic antigen (CEA)+anti-p53+osteopontin+seprase+ferritin]. The diagnostic performance of individual markers and marker combinations was assessed and compared with stool test results. AUCs for the detection of colorectal cancer and advanced adenomas with the 5-marker blood test were 0.78 [95% confidence interval (CI), 0.68-0.87] and 0.56 (95% CI, 0.53-0.59), respectively, which now is comparable with guaiac-based fecal occult blood test (gFOBT) but inferior to FIT. With cutoffs yielding specificities of 80%, 90%, and 95%, the sensitivities for the detection of colorectal cancer were 64%, 50%, and 42%, and early-stage cancers were detected as well as late-stage cancers. For osteopontin, seprase, and ferritin, the diagnostic performance in the screening setting was reduced compared with previous studies in diagnostic settings while CEA and anti-p53 showed similar diagnostic performance in both settings. Performance of the 5-marker blood test under screening conditions is inferior to FIT even though it is still comparable with the performance of gFOBT. CEA and anti-p53 could contribute to the development of a multiple marker blood-based test for early detection of colorectal cancer. ©2015 American Association for Cancer Research.

Diagnostic performance of focused cardiac ultrasound performed by emergency physicians for the assessment of ascending aorta dilation and aneurysm.

PubMed

Nazerian, Peiman; Vanni, Simone; Morello, Fulvio; Castelli, Matteo; Ottaviani, Maddalena; Casula, Claudia; Petrioli, Alessandra; Bartolucci, Maurizio; Grifoni, Stefano

2015-05-01

The diagnostic performance of transthoracic focused cardiac ultrasound (FoCUS) performed by emergency physicians (EP) to estimate ascending aorta dimensions in the acute setting has not been prospectively studied. The diagnostic accuracy and the interobserver variability of EP-performed FoCUS were investigated to estimate thoracic aortic dilation and aneurysm compared with the results of computed tomography angiography (CTA). This was a prospective single-center cohort study of a convenience sample of patients who underwent CTA in the emergency department for suspected aortic pathology. FoCUS was performed before CTA, and the maximum ascending aorta diameter evaluated in parasternal long-axis view. Aorta diameter < 40 mm by visual estimation or by diameter measurement was considered normal. Measurements were recorded in all patients with aorta diameter ≥ 40 mm. Diagnostic accuracy of FoCUS for detection of aortic dilation (diameter ≥ 40 mm) and aneurysm (diameter ≥ 45 mm) were calculated considering the CTA result as reference standard. In a subgroup of patients, a second EP-sonographer performed FoCUS to evaluate interobserver agreement for the diagnosis of ascending aorta dilation. A total of 140 patients were enrolled in the study. Ascending aorta dilation and aneurysm were detected with FoCUS in 50 (35.7%) and in 27 (17.8%) patients, respectively. Sensitivity and specificity of FoCUS were 78.6% (95% confidence interval [CI] = 65.6% to 88.4%) and 92.9% (95% CI = 85.1% to 97.3%), respectively, for ascending aorta dilation and 64.7% (95% CI = 46.5% to 80.2%) and 95.3% (95% CI = 89.3% to 98.4%), respectively, for ascending aorta aneurysm. Interobserver agreement of FoCUS was k = 0.82. FoCUS performed by EP is specific for ascending aorta dilation and aneurysm when compared to CTA and appears a reproducible technique. © 2015 by the Society for Academic Emergency Medicine.

Repeatability and Diagnostic Value of Nasal Potential Difference in a Genetically Admixed Population.

PubMed

Sad, Izabela Rocha; Higa, Laurinda Yoko Shinzato; Leal, Teresinha; Martins, Raisa da Silva; de Almeida, Ana Claudia; Ramos, Eloane Goncalves; de Cabello, Giselda Maria Kalil; Peixoto, Maria Virginia Marques

2016-01-01

The genetic diversity of the Brazilian population results from three ethnic groups admixture: Europeans, Africans and Amerindians, thus increasing the difficulty of performing cystic fibrosis (CF) diagnosis. The nasal potential difference (NPD) evaluates the cystic fibrosis transmembrane conductance regulator (CFTR) and epithelial sodium channel (ENaC) activity. Despite being a useful CF diagnostic test and a biomarker of CFTR-modulator drugs, it is also highly operator dependent. Therefore, it may be difficult to get accurate results and to interpret them. Wilschanski and Sermet scores were proposed to address these issues. This study aimed to evaluate repeatability and diagnostic value of NPD parameters and Wilschanski and Sermet scores in a CF center in Rio de Janeiro. NPD was performed in 78 subjects. Maximal PD, amiloride response, total chloride response, and Wilschanski and Sermet scores were explored as means (confidence interval, CI). One-way ANOVA was used to compare mean differences and Scheffe test was used to pair-wise comparisons. Repeatability was evaluated by scatter and Bland-Altman plots. The Ethics Committee of the CF Center has approved the study protocol. Parents and adult participants signed an informed consent form. Forty-eight healthy-volunteers, 19 non-CF and 11 CF patients were enrolled in this study. Significant differences were found when comparing CF patients' NPD parameters to the other two groups (P = 0.000). Moreover, no significant differences were found when parameters from non-CF patients were compared with those from healthy volunteers (P > 0.05). The means of NPD parameters and diagnostic scores of each group were in concordance with disease/non-disease conditions. The repeatability data - Wilschanski and Sermet and NPD - allow NPD to be performed in this Brazilian CF Center. The present study gathered consistent data for Bland-Altman plots. The results of Wilschanski and Sermet diagnostic scores suggest that they were concordant with CF/non-CF conditions. More NPD tests should be performed in the Rio de Janeiro CF dynamic cohort to contribute to international NPD validation studies and to provide NPD as a biomarker in Brazil.

Repeatability and Diagnostic Value of Nasal Potential Difference in a Genetically Admixed Population

PubMed Central

Sad, Izabela Rocha; Higa, Laurinda Yoko Shinzato; Leal, Teresinha; Martins, Raisa da Silva; de Almeida, Ana Claudia; Ramos, Eloane Goncalves; de Cabello, Giselda Maria Kalil; Peixoto, Maria Virginia Marques

2016-01-01

Background The genetic diversity of the Brazilian population results from three ethnic groups admixture: Europeans, Africans and Amerindians, thus increasing the difficulty of performing cystic fibrosis (CF) diagnosis. The nasal potential difference (NPD) evaluates the cystic fibrosis transmembrane conductance regulator (CFTR) and epithelial sodium channel (ENaC) activity. Despite being a useful CF diagnostic test and a biomarker of CFTR-modulator drugs, it is also highly operator dependent. Therefore, it may be difficult to get accurate results and to interpret them. Wilschanski and Sermet scores were proposed to address these issues. This study aimed to evaluate repeatability and diagnostic value of NPD parameters and Wilschanski and Sermet scores in a CF center in Rio de Janeiro. Methods NPD was performed in 78 subjects. Maximal PD, amiloride response, total chloride response, and Wilschanski and Sermet scores were explored as means (confidence interval, CI). One-way ANOVA was used to compare mean differences and Scheffe test was used to pair-wise comparisons. Repeatability was evaluated by scatter and Bland-Altman plots. The Ethics Committee of the CF Center has approved the study protocol. Parents and adult participants signed an informed consent form. Results Forty-eight healthy-volunteers, 19 non-CF and 11 CF patients were enrolled in this study. Significant differences were found when comparing CF patients’ NPD parameters to the other two groups (P = 0.000). Moreover, no significant differences were found when parameters from non-CF patients were compared with those from healthy volunteers (P > 0.05). The means of NPD parameters and diagnostic scores of each group were in concordance with disease/non-disease conditions. The repeatability data - Wilschanski and Sermet and NPD - allow NPD to be performed in this Brazilian CF Center. Conclusions The present study gathered consistent data for Bland-Altman plots. The results of Wilschanski and Sermet diagnostic scores suggest that they were concordant with CF/non-CF conditions. More NPD tests should be performed in the Rio de Janeiro CF dynamic cohort to contribute to international NPD validation studies and to provide NPD as a biomarker in Brazil. PMID:26668678

The Diagnostic Efficacy of Cone-beam Computed Tomography in Endodontics: A Systematic Review and Analysis by a Hierarchical Model of Efficacy.

PubMed

Rosen, Eyal; Taschieri, Silvio; Del Fabbro, Massimo; Beitlitum, Ilan; Tsesis, Igor

2015-07-01

The aim of this study was to evaluate the diagnostic efficacy of cone-beam computed tomographic (CBCT) imaging in endodontics based on a systematic search and analysis of the literature using an efficacy model. A systematic search of the literature was performed to identify studies evaluating the use of CBCT imaging in endodontics. The identified studies were subjected to strict inclusion criteria followed by an analysis using a hierarchical model of efficacy (model) designed for appraisal of the literature on the levels of efficacy of a diagnostic imaging modality. Initially, 485 possible relevant articles were identified. After title and abstract screening and a full-text evaluation, 58 articles (12%) that met the inclusion criteria were analyzed and allocated to levels of efficacy. Most eligible articles (n = 52, 90%) evaluated technical characteristics or the accuracy of CBCT imaging, which was defined in this model as low levels of efficacy. Only 6 articles (10%) proclaimed to evaluate the efficacy of CBCT imaging to support the practitioner's decision making; treatment planning; and, ultimately, the treatment outcome, which was defined as higher levels of efficacy. The expected ultimate benefit of CBCT imaging to the endodontic patient as evaluated by its level of diagnostic efficacy is unclear and is mainly limited to its technical and diagnostic accuracy efficacies. Even for these low levels of efficacy, current knowledge is limited. Therefore, a cautious and rational approach is advised when considering CBCT imaging for endodontic purposes. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Tomosynthesis for the early detection of pulmonary emphysema: diagnostic performance compared with chest radiography, using multidetector computed tomography as reference.

PubMed

Yamada, Yoshitake; Jinzaki, Masahiro; Hashimoto, Masahiro; Shiomi, Eisuke; Abe, Takayuki; Kuribayashi, Sachio; Ogawa, Kenji

2013-08-01

To compare the diagnostic performance of tomosynthesis with that of chest radiography for the detection of pulmonary emphysema, using multidetector computed tomography (MDCT) as reference. Forty-eight patients with and 63 without pulmonary emphysema underwent chest MDCT, tomosynthesis and radiography on the same day. Two blinded radiologists independently evaluated the tomosynthesis images and radiographs for the presence of pulmonary emphysema. Axial and coronal MDCT images served as the reference standard and the percentage lung volume with attenuation values of -950 HU or lower (LAA-950) was evaluated to determine the extent of emphysema. Receiver-operating characteristic (ROC) analysis and generalised estimating equations model were used. ROC analysis revealed significantly better performance (P < 0.0001) of tomosynthesis than radiography for the detection of pulmonary emphysema. The average sensitivity, specificity, positive predictive value and negative predictive value of tomosynthesis were 0.875, 0.968, 0.955 and 0.910, respectively, whereas the values for radiography were 0.479, 0.913, 0.815 and 0.697, respectively. For both tomosynthesis and radiography, the sensitivity increased with increasing LAA-950. The diagnostic performance of tomosynthesis was significantly superior to that of radiography for the detection of pulmonary emphysema. In both tomosynthesis and radiography, the sensitivity was affected by the LAA-950. • Tomosynthesis showed significantly better diagnostic performance for pulmonary emphysema than radiography. • Interobserver agreement for tomosynthesis was significantly higher than that for radiography. • Sensitivity increased with increasing LAA -950 in both tomosynthesis and radiography. • Tomosynthesis imparts a similar radiation dose to two projection chest radiography. • Radiation dose and cost of tomosynthesis are lower than those of MDCT.

Educational agenda for diagnostic error reduction

PubMed Central

Trowbridge, Robert L; Dhaliwal, Gurpreet; Cosby, Karen S

2013-01-01

Diagnostic errors are a major patient safety concern. Although the majority of diagnostic errors are partially attributable to cognitive mistakes, the most effective means of improving clinician cognition in order to achieve gains in diagnostic reliability are unclear. We propose a tripartite educational agenda for improving diagnostic performance among students, residents and practising physicians. This agenda includes strengthening the metacognitive abilities of clinicians, fostering intuitive reasoning and increasing awareness of the role of systems in the diagnostic process. The evidence supporting initiatives in each of these realms is reviewed and a course of future implementation and study is proposed. The barriers to designing and implementing this agenda are substantial and include limited evidence supporting these initiatives and the challenges of changing the practice patterns of practising physicians. Implementation will need to be accompanied by rigorous evaluation. PMID:23764435

Comparison of 21-Gauge and 22-Gauge Aspiration Needle in Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration

PubMed Central

Akulian, Jason; Lechtzin, Noah; Yasin, Faiza; Kamdar, Biren; Ernst, Armin; Ost, David E.; Ray, Cynthia; Greenhill, Sarah R.; Jimenez, Carlos A.; Filner, Joshua; Feller-Kopman, David

2013-01-01

Background: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive procedure originally performed using a 22-gauge (22G) needle. A recently introduced 21-gauge (21G) needle may improve the diagnostic yield and sample adequacy of EBUS-TBNA, but prior smaller studies have shown conflicting results. To our knowledge, this is the largest study undertaken to date to determine whether the 21G needle adds diagnostic benefit. Methods: We retrospectively evaluated the results of 1,299 patients from the American College of Chest Physicians Quality Improvement Registry, Education, and Evaluation (AQuIRE) Diagnostic Registry who underwent EBUS-TBNA between February 2009 and September 2010 at six centers throughout the United States. Data collection included patient demographics, sample adequacy, and diagnostic yield. Analysis consisted of univariate and multivariate hierarchical logistic regression comparing diagnostic yield and sample adequacy of EBUS-TBNA specimens by needle gauge. Results: A total of 1,235 patients met inclusion criteria. Sample adequacy was obtained in 94.9% of the 22G needle group and in 94.6% of the 21G needle group (P = .81). A diagnosis was made in 51.4% of the 22G and 51.3% of the 21G groups (P = .98). Multivariate hierarchical logistic regression showed no statistical difference in sample adequacy or diagnostic yield between the two groups. The presence of rapid onsite cytologic evaluation was associated with significantly fewer needle passes per procedure when using the 21G needle (P < .001). Conclusions: There is no difference in specimen adequacy or diagnostic yield between the 21G and 22G needle groups. EBUS-TBNA in conjunction with rapid onsite cytologic evaluation and a 21G needle is associated with fewer needle passes compared with a 22G needle. PMID:23632441

Alcohol Use Disorders in Argentinian Girls and Women 12 Months Before Delivery: Comparison of DSM-IV, DSM-5, and ICD-10 Diagnostic Criteria.

PubMed

López, Mariana B; Conde, Karina; Cremonte, Mariana

The evidence of important problems related to prenatal alcohol exposure has faced researchers with the problem of understanding and screening alcohol use in this population. Although any alcohol use should be considered risky during pregnancy, identifying alcohol-drinking problems (ADPs) could be especially important because women with ADPs could not benefit from a simple advice of abstinence and because their offsprings are subjected to a higher risk of problems related with prenatal alcohol exposure. In this context, we aim to study the prevalence and characteristics of ADPs in pregnant women, evaluating the performance of different diagnostic systems in this population. The aims of the study were to describe the prevalence of ADPs obtained with the criteria of the Diagnostic and Statistical Manual of Mental Disorders in its fourth (DSM-IV) and fifth edition (DSM-5), and the International Classification of Diseases (ICD)-10, in Argentinean females aged 13 to 44 years, 12 months before delivery; to evaluate the level of agreement between these classification systems; and to analyze the performance of each diagnosis criterion in this population. Data were collected through personal interviews of a probability sample of puerperal women (N = 641) in the city of Santa Fe (Argentina), between October 2010 and February 2011. Diagnoses compatible with DSM-IV, DSM-5, and ICD-10 were obtained through the Composite International Diagnostic Interview. Agreement among diagnostic systems was measured through Cohen kappa. Diagnosis criteria performance were analyzed considering their prevalence and discriminating ability (D value). Total ADP prevalence was 6.4% for DSM-IV (4.2% abuse and 2.2% dependence), 8.1% for DSM-5 (6.4% mild, 0.8% moderate, and 0.9% severe alcohol use disorder), and 14.1% for the ICD-10 (11.9% harmful use and 2.2% dependence). DSM-5 modifications improved agreement between DSM and ICD. The least prevalent and worst discriminating ability diagnostic criterion was "legal problems." The most prevalent and 1 of the best discriminating ability diagnostic criterion was '"health issues." DSM-IV and ICD-10 dependence prevalence was similar to that of previous studies in pregnant women, whereas abuse prevalence was surprisingly higher. Our results indicate a better performance of the DSM-5 alcohol use disorder category relative to the DSM-IV dual categorization. Nevertheless, the poor diagnostic performance of some DSM-5 criteria in this population could evidence their intercultural variability.

Diagnostic performance of osteocalcin measurements in patients with endogenous Cushing's syndrome.

PubMed

Belaya, Zhanna E; Iljin, Alexander V; Melnichenko, Galina A; Solodovnikov, Alexander G; Rozhinskaya, Liudmila Y; Dzeranova, Larisa K; Dedov, Ivan I

2016-01-01

The aim of this study was to evaluate the diagnostic performance of osteocalcin (OC), as measured by automated electrochemiluminescence immunoassay (ECLIA), in identifying Cushing's syndrome (CS) in two separate populations: among obese and overweight subjects and among women of postmenopausal age with osteoporosis. Among the 106 referral patients with obesity, CS was confirmed in 42 cases. The patients of the referred population provided late-night salivary cortisol (LNSC), underwent low-dose dexamethasone suppression testing (DST) and were further evaluated until CS was pathologically confirmed. A threshold of OC-8.3 ng ml(-1) differentiated CS among obese and overweight subjects with a sensitivity of 73.8% (95% confidence interval (CI) 58.9-84.7) and a specificity of 96.9% (95% CI 89.3-99.1). The total area under the receiver operating characteristic curve (AUC) was 0.859 (95% CI 0.773-0.945), which was lower than LNSC or DST (P=0.01). In the retrospective portion of the study, the OC levels were evaluated in 67 subjects with newly diagnosed postmenopausal osteoporosis and in 23 patients (older than 45) with newly diagnosed CS and osteoporosis (presence of low traumatic fractures or T-score P-2.5). The diagnostic performance of OC for osteoporosis due to CS was within an AUC of 0.959 (95% CI 0.887-1.00). A threshold for OC of 8.3 ng ml-1 yielded a sensitivity of 95.4% (95% CI 78.2-99.2%) and a specificity of 98.5% (95% CI 92.0-99.7%). Thus, osteocalcin could be used in the diagnostic testing for endogenous hypercortisolism in patients referred to exclude CS and to identify CS among patients of postmenopausal age with osteoporosis.

Diagnostic performance of osteocalcin measurements in patients with endogenous Cushing's syndrome

PubMed Central

Belaya, Zhanna E; Iljin, Alexander V; Melnichenko, Galina A; Solodovnikov, Alexander G; Rozhinskaya, Liudmila Y; Dzeranova, Larisa K; Dedov, Ivan I

2016-01-01

The aim of this study was to evaluate the diagnostic performance of osteocalcin (OC), as measured by automated electrochemiluminescence immunoassay (ECLIA), in identifying Cushing's syndrome (CS) in two separate populations: among obese and overweight subjects and among women of postmenopausal age with osteoporosis. Among the 106 referral patients with obesity, CS was confirmed in 42 cases. The patients of the referred population provided late-night salivary cortisol (LNSC), underwent low-dose dexamethasone suppression testing (DST) and were further evaluated until CS was pathologically confirmed. A threshold of OC—8.3 ng ml−1 differentiated CS among obese and overweight subjects with a sensitivity of 73.8% (95% confidence interval (CI) 58.9–84.7) and a specificity of 96.9% (95% CI 89.3–99.1). The total area under the receiver operating characteristic curve (AUC) was 0.859 (95% CI 0.773–0.945), which was lower than LNSC or DST (P=0.01). In the retrospective portion of the study, the OC levels were evaluated in 67 subjects with newly diagnosed postmenopausal osteoporosis and in 23 patients (older than 45) with newly diagnosed CS and osteoporosis (presence of low traumatic fractures or T-score P–2.5). The diagnostic performance of OC for osteoporosis due to CS was within an AUC of 0.959 (95% CI 0.887–1.00). A threshold for OC of 8.3 ng ml-1 yielded a sensitivity of 95.4% (95% CI 78.2–99.2%) and a specificity of 98.5% (95% CI 92.0–99.7%). Thus, osteocalcin could be used in the diagnostic testing for endogenous hypercortisolism in patients referred to exclude CS and to identify CS among patients of postmenopausal age with osteoporosis. PMID:27347399

The Comparison of Matching Methods Using Different Measures of Balance: Benefits and Risks Exemplified within a Study to Evaluate the Effects of German Disease Management Programs on Long-Term Outcomes of Patients with Type 2 Diabetes.

PubMed

Fullerton, Birgit; Pöhlmann, Boris; Krohn, Robert; Adams, John L; Gerlach, Ferdinand M; Erler, Antje

2016-10-01

To present a case study on how to compare various matching methods applying different measures of balance and to point out some pitfalls involved in relying on such measures. Administrative claims data from a German statutory health insurance fund covering the years 2004-2008. We applied three different covariance balance diagnostics to a choice of 12 different matching methods used to evaluate the effectiveness of the German disease management program for type 2 diabetes (DMPDM2). We further compared the effect estimates resulting from applying these different matching techniques in the evaluation of the DMPDM2. The choice of balance measure leads to different results on the performance of the applied matching methods. Exact matching methods performed well across all measures of balance, but resulted in the exclusion of many observations, leading to a change of the baseline characteristics of the study sample and also the effect estimate of the DMPDM2. All PS-based methods showed similar effect estimates. Applying a higher matching ratio and using a larger variable set generally resulted in better balance. Using a generalized boosted instead of a logistic regression model showed slightly better performance for balance diagnostics taking into account imbalances at higher moments. Best practice should include the application of several matching methods and thorough balance diagnostics. Applying matching techniques can provide a useful preprocessing step to reveal areas of the data that lack common support. The use of different balance diagnostics can be helpful for the interpretation of different effect estimates found with different matching methods. © Health Research and Educational Trust.

The Proposed MACRA/MIPS Threshold for Patient-Facing Encounters: What It Means for Radiologists.

PubMed

Rosenkrantz, Andrew B; Hirsch, Joshua A; Allen, Bibb; Wang, Wenyi; Hughes, Danny R; Nicola, Gregory N

2017-03-01

In implementing the Merit-Based Incentive Payment System (MIPS), CMS will provide special considerations to physicians with infrequent face-to-face patient encounters by reweighting MIPS performance categories to account for the unique circumstances facing these providers. The aim of this study was to determine the impact of varying criteria on the fraction of radiologists who are likely to receive special considerations for performance assessment under MIPS. Data from the 2014 Medicare Physician and Other Supplier file for 28,710 diagnostic radiologists were used to determine the fraction of radiologists meeting various proposed criteria for receiving special considerations. For each definition, the fraction of patient-facing encounters among all billed codes was determined for those radiologists not receiving special considerations. When using the criterion proposed by CMS that physicians will receive special considerations if billing ≤25 evaluation and management services or surgical codes, 72.0% of diagnostic radiologists would receive special considerations, though such encounters would represent only 2.1% of billed codes among remaining diagnostic radiologists without special considerations. If CMS were to apply an alternative criterion of billing ≤100 evaluation and management codes exclusively, 98.8% of diagnostic radiologists would receive special considerations. At this threshold, patient-facing encounters would represent approximately 10% of billed codes among remaining radiologists without special considerations. The current CMS proposed criterion for special considerations would result in a considerable fraction of radiologists being evaluated on the basis of measures that are not reflective of their practice and beyond their direct control. Alternative criteria could help ensure that radiologists are provided a fair opportunity for success in performance review under the MIPS. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Diagnostic performance of cytology for assessment of hepatic lipid content in dairy cattle.

PubMed

Fry, M M; Yao, B; Ríos, C; Wong, C; Mann, S; McArt, J A A; Nydam, D V; Leal Yepes, F A; Viesselmann, L; Geick, A; Goldin, K; Jordan, A; Behling-Kelly, E

2018-02-01

The objective of our study was to characterize the diagnostic performance of cytology for assessing hepatic lipid content (HLC) in dairy cows by comparing microscopic evaluation of lipid vacuolation in touch imprint slide preparations of liver biopsies with quantitative measurement of triglyceride concentration ([TG]; mg/mg of wet weight) in paired biopsy samples. Our study also sought to compare the diagnostic performance of liver cytology, plasma nonesterified fatty acid concentration ([NEFA]), and plasma β-hydroxybutyrate concentration ([BHB]) derived from a measurement performed on whole blood, for assessing HLC. Chemical extraction of TG from liver tissue remains the gold standard for quantifying HLC, largely because available blood tests, although useful for detecting some types of pathology, such as increased lipid mobilization, ketosis, or hepatocellular injury, are nonspecific as to etiology. Veterinary practitioners can sample bovine liver for cytological evaluation in a fast, minimally invasive, and inexpensive manner. Thus, if highly predictive of HLC, cytology would be a practical diagnostic tool for dairy veterinarians. In our study, liver biopsy samples from Holstein cows (219 samples from 105 cows: 52 from cows 2 to 20 d prepartum, 105 from cows 0 to 10 d in milk, 62 from cows 18 to 25 d in milk) were used to prepare cytology slides and to quantify [TG] using the Folch extraction method followed by the Hantzch condensation reaction and spectrophotometric measurement. An ordinal scale (0-4) based on amount of hepatocellular cytoplasm occupied by discrete clear vacuoles was used by 3 blinded, independent observers to rank HLC in Wright-Giemsa-stained slides. Interobserver agreement in cytology scoring was good. Corresponding plasma [NEFA] and [BHB] measurements were available for 187 and 195 of the 219 samples, respectively. Liver [TG] correlated more strongly with cytology score than with NEFA or BHB, and receiver operating characteristic curve analysis showed that cytology had better diagnostic performance than either NEFA or BHB for correctly categorizing [TG] at thresholds of 5, 10, and 15%. Hepatic lipidosis in high-producing dairy cows is of major clinical and economic importance, and this study demonstrates that cytology is an accurate means of assessing HLC. Additional work is indicated to evaluate the diagnostic utility of liver cytology. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

The usefulness of the sum of relative enhancement ratio in making a differential diagnosis of hepatocellular carcinoma from cirrhosis-related nodules.

PubMed

Yoon, Ki Woong; Song, Ji Soo; Han, Young Min

2014-01-01

To estimate the diagnostic accuracy of the sum of relative enhancement ratio (sRER) in making a differential diagnosis of hepatocellular carcinoma (HCC) from benign cirrhosis-related nodules. Eighteen benign cirrhosis-related nodules and 18 HCCs were evaluated. Three radiologists independently reviewed computed tomography images using visual assessment and sRER. sRER was estimated by adding region-of-interest measurement in the arterial phase and the delayed phase. Diagnostic performance and accuracy were evaluated. The mean values of sRER were significantly higher in HCCs than in benign cirrhosis-related nodules. The sRER method improved diagnostic accuracy of differentiating HCCs from benign cirrhosis-related nodules. Copyright © 2014 Elsevier Inc. All rights reserved.

Extrinsic and Intrinsic Help-Seeking Motivation in the Assessment of Cognitive Decline.

PubMed

Haussmann, Robert; Mayer-Pelinski, René; Borchardt, Maike; Beier, Fabrice; Helling, Franziska; Buthut, Maria; Meissner, Gisa; Lange, Jan; Zweiniger, Anne; Donix, Markus

2018-06-01

Diagnostic assessments for dementia include the evaluation of subjective memory impairment, dementia worries, or depressive symptoms. Data on the predictive value of these factors remain unclear, and varying help-seeking behavior may contribute to this finding. We investigate whether differentiating help-seeking motivation from other psychological factors associated with cognitive impairment would enhance the prediction of diagnostic outcomes in a memory clinic. We obtained information on help-seeking motivation from 171 patients who underwent routine diagnostic assessments. Utilizing a discriminant correspondence analysis, our results indicate that extrinsic motivation increases the likelihood of receiving a dementia diagnosis, whereas depression or the duration of deficits carries discriminatory information to further guide the differentiation of prodromal dementia. Recognizing motivational aspects of help-seeking behavior can complement the clinical evaluation of cognitive performance.

Demographic and Practice Characteristics of Pathologists Who Enjoy Breast Tissue Interpretation

PubMed Central

Oster, Natalia V.; Geller, Berta; Carney, Patricia A.; Reisch, Lisa M.; Onega, Tracy; Weaver, Donald L.; Frederick, Paul; Elmore, Joann G.

2015-01-01

Summary Physician attributes, job satisfaction and confidence in clinical skills are associated with enhanced performance and better patient outcomes. We surveyed 252 pathologists to evaluate associations between enjoyment of breast pathology, demographic/clinical characteristics and diagnostic performance. Diagnostic performance was determined by agreement with patient cases previously reviewed by a panel of experienced pathologists. Eighty-three percent of study participants reported enjoying breast pathology. Pathologists who enjoy breast interpretation were more likely to review ≥10 cases/week (p=0.003), report breast interpretation expertise (p=0.013), and high levels of confidence interpreting breast pathology (p<0.001). These pathologists were less likely to report that the field was challenging (p<0.001) and that breast cases make them more nervous than other types of pathology (p<0.001). Enjoyment was not associated with diagnostic performance. Millions of women undergo breast biopsy annually, thus it is reassuring that although nearly a fifth of practicing pathologists who interpret breast tissue report not enjoying the field, precision is not impacted. PMID:25554017

Towards intelligent diagnostic system employing integration of mathematical and engineering model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isa, Nor Ashidi Mat

The development of medical diagnostic system has been one of the main research fields during years. The goal of the medical diagnostic system is to place a nosological system that could ease the diagnostic evaluation normally performed by scientists and doctors. Efficient diagnostic evaluation is essentials and requires broad knowledge in order to improve conventional diagnostic system. Several approaches on developing the medical diagnostic system have been designed and tested since the earliest 60s. Attempts on improving their performance have been made which utilizes the fields of artificial intelligence, statistical analyses, mathematical model and engineering theories. With the availability ofmore » the microcomputer and software development as well as the promising aforementioned fields, medical diagnostic prototypes could be developed. In general, the medical diagnostic system consists of several stages, namely the 1) data acquisition, 2) feature extraction, 3) feature selection, and 4) classifications stages. Data acquisition stage plays an important role in converting the inputs measured from the real world physical conditions to the digital numeric values that can be manipulated by the computer system. One of the common medical inputs could be medical microscopic images, radiographic images, magnetic resonance image (MRI) as well as medical signals such as electrocardiogram (ECG) and electroencephalogram (EEG). Normally, the scientist or doctors have to deal with myriad of data and redundant to be processed. In order to reduce the complexity of the diagnosis process, only the significant features of the raw data such as peak value of the ECG signal or size of lesion in the mammogram images will be extracted and considered in the subsequent stages. Mathematical models and statistical analyses will be performed to select the most significant features to be classified. The statistical analyses such as principal component analysis and discriminant analysis as well as mathematical model of clustering technique have been widely used in developing the medical diagnostic systems. The selected features will be classified using mathematical models that embedded engineering theory such as artificial intelligence, support vector machine, neural network and fuzzy-neuro system. These classifiers will provide the diagnostic results without human intervention. Among many publishable researches, several prototypes have been developed namely NeuralPap, Neural Mammo, and Cervix Kit. The former system (NeuralPap) is an automatic intelligent diagnostic system for classifying and distinguishing between the normal and cervical cancerous cells. Meanwhile, the Cervix Kit is a portable Field-programmable gate array (FPGA)-based cervical diagnostic kit that could automatically diagnose the cancerous cell based on the images obtained during sampling test. Besides the cervical diagnostic system, the Neural Mammo system is developed to specifically aid the diagnosis of breast cancer using a fine needle aspiration image.« less

Towards intelligent diagnostic system employing integration of mathematical and engineering model

NASA Astrophysics Data System (ADS)

Isa, Nor Ashidi Mat

2015-05-01

The development of medical diagnostic system has been one of the main research fields during years. The goal of the medical diagnostic system is to place a nosological system that could ease the diagnostic evaluation normally performed by scientists and doctors. Efficient diagnostic evaluation is essentials and requires broad knowledge in order to improve conventional diagnostic system. Several approaches on developing the medical diagnostic system have been designed and tested since the earliest 60s. Attempts on improving their performance have been made which utilizes the fields of artificial intelligence, statistical analyses, mathematical model and engineering theories. With the availability of the microcomputer and software development as well as the promising aforementioned fields, medical diagnostic prototypes could be developed. In general, the medical diagnostic system consists of several stages, namely the 1) data acquisition, 2) feature extraction, 3) feature selection, and 4) classifications stages. Data acquisition stage plays an important role in converting the inputs measured from the real world physical conditions to the digital numeric values that can be manipulated by the computer system. One of the common medical inputs could be medical microscopic images, radiographic images, magnetic resonance image (MRI) as well as medical signals such as electrocardiogram (ECG) and electroencephalogram (EEG). Normally, the scientist or doctors have to deal with myriad of data and redundant to be processed. In order to reduce the complexity of the diagnosis process, only the significant features of the raw data such as peak value of the ECG signal or size of lesion in the mammogram images will be extracted and considered in the subsequent stages. Mathematical models and statistical analyses will be performed to select the most significant features to be classified. The statistical analyses such as principal component analysis and discriminant analysis as well as mathematical model of clustering technique have been widely used in developing the medical diagnostic systems. The selected features will be classified using mathematical models that embedded engineering theory such as artificial intelligence, support vector machine, neural network and fuzzy-neuro system. These classifiers will provide the diagnostic results without human intervention. Among many publishable researches, several prototypes have been developed namely NeuralPap, Neural Mammo, and Cervix Kit. The former system (NeuralPap) is an automatic intelligent diagnostic system for classifying and distinguishing between the normal and cervical cancerous cells. Meanwhile, the Cervix Kit is a portable Field-programmable gate array (FPGA)-based cervical diagnostic kit that could automatically diagnose the cancerous cell based on the images obtained during sampling test. Besides the cervical diagnostic system, the Neural Mammo system is developed to specifically aid the diagnosis of breast cancer using a fine needle aspiration image.

The effect of general anesthesia versus intravenous sedation on diagnostic yield and success in electromagnetic navigation bronchoscopy.

PubMed

Bowling, Mark R; Kohan, Matthew W; Walker, Paul; Efird, Jimmy; Ben Or, Sharon

2015-01-01

Navigational bronchoscopy is utilized to guide biopsies of peripheral lung nodules and place fiducial markers for treatment of limited stage lung cancer with stereotactic body radiotherapy. The type of sedation used for this procedure remains controversial. We performed a retrospective chart review to evaluate the differences of diagnostic yield and overall success of the procedure based on anesthesia type. Electromagnetic navigational bronchoscopy was performed using the superDimension software system. Once the targeted lesion was within reach, multiple tissue samples were obtained. Statistical analysis was used to correlate the yield with the type of sedation among other factors. A successful procedure was defined if a diagnosis was made or a fiducial marker was adequately placed. Navigational bronchoscopy was performed on a total of 120 targeted lesions. The overall complication rate of the procedure was 4.1%. The diagnostic yield and success of the procedure was 74% and 87%, respectively. Duration of the procedure was the only significant difference between the general anesthesia and IV sedation groups (mean, 58 vs. 43 min, P=0.0005). A larger tumor size was associated with a higher diagnostic yield (P=0.032). All other variables in terms of effect on diagnostic yield and an unsuccessful procedure did not meet statistical significance. Navigational bronchoscopy is a safe and effective pulmonary diagnostic tool with relatively low complication rate. The diagnostic yield and overall success of the procedure does not seem to be affected by the type of sedation used.

IOTA Simple Rules in Differentiating between Benign and Malignant Adnexal Masses by Non-expert Examiners.

PubMed

Tinnangwattana, Dangcheewan; Vichak-Ururote, Linlada; Tontivuthikul, Paponrad; Charoenratana, Cholaros; Lerthiranwong, Thitikarn; Tongsong, Theera

2015-01-01

To evaluate the diagnostic performance of IOTA simple rules in predicting malignant adnexal tumors by non-expert examiners. Five obstetric/gynecologic residents, who had never performed gynecologic ultrasound examination by themselves before, were trained for IOTA simple rules by an experienced examiner. One trained resident performed ultrasound examinations including IOTA simple rules on 100 women, who were scheduled for surgery due to ovarian masses, within 24 hours of surgery. The gold standard diagnosis was based on pathological or operative findings. The five-trained residents performed IOTA simple rules on 30 patients for evaluation of inter-observer variability. A total of 100 patients underwent ultrasound examination for the IOTA simple rules. Of them, IOTA simple rules could be applied in 94 (94%) masses including 71 (71.0%) benign masses and 29 (29.0%) malignant masses. The diagnostic performance of IOTA simple rules showed sensitivity of 89.3% (95%CI, 77.8%; 100.7%), specificity 83.3% (95%CI, 74.3%; 92.3%). Inter-observer variability was analyzed using Cohen's kappa coefficient. Kappa indices of the four pairs of raters are 0.713-0.884 (0.722, 0.827, 0.713, and 0.884). IOTA simple rules have high diagnostic performance in discriminating adnexal masses even when are applied by non-expert sonographers, though a training course may be required. Nevertheless, they should be further tested by a greater number of general practitioners before widely use.

Diagnosing periprosthetic joint infection: has the era of the biomarker arrived?

PubMed

Deirmengian, Carl; Kardos, Keith; Kilmartin, Patrick; Cameron, Alexander; Schiller, Kevin; Parvizi, Javad

2014-11-01

The diagnosis of periprosthetic joint infection (PJI) remains a serious clinical challenge. There is a pressing need for improved diagnostic testing methods; biomarkers offer one potentially promising approach. We evaluated the diagnostic characteristics of 16 promising synovial fluid biomarkers for the diagnosis of PJI. Synovial fluid was collected from 95 patients meeting the inclusion criteria of this prospective diagnostic study. All patients were being evaluated for a revision hip or knee arthroplasty, including patients with systemic inflammatory disease and those already receiving antibiotic treatment. The Musculoskeletal Infection Society (MSIS) definition was used to classify 29 PJIs and 66 aseptic joints. Synovial fluid samples were tested by immunoassay for 16 biomarkers optimized for use in synovial fluid. Sensitivity, specificity, and receiver operating characteristic curve analysis were performed to assess for diagnostic performance. Five biomarkers, including human α-defensin 1-3, neutrophil elastase 2, bactericidal/permeability-increasing protein, neutrophil gelatinase-associated lipocalin, and lactoferrin, correctly predicted the MSIS classification of all patients in this study, with 100% sensitivity and specificity for the diagnosis of PJI. An additional eight biomarkers demonstrated excellent diagnostic strength, with an area under the curve of greater than 0.9. Synovial fluid biomarkers exhibit a high accuracy in diagnosing PJI, even when including patients with systemic inflammatory disease and those receiving antibiotic treatment. Considering that these biomarkers match the results of the more complex MSIS definition of PJI, we believe that synovial fluid biomarkers can be a valuable addition to the methods utilized for the diagnosis of infection. Level II, diagnostic study. See Instructions for Authors for a complete description of levels of evidence.

Systematic review of proposed definitions of nocturnal polyuria and population-based evidence of their diagnostic accuracy.

PubMed

Olesen, Tine Kold; Denys, Marie-Astrid; Vande Walle, Johan; Everaert, Karel

2018-02-06

Background Evidence of diagnostic accuracy for proposed definitions of nocturnal polyuria is currently unclear. Purpose Systematic review to determine population-based evidence of the diagnostic accuracy of proposed definitions of nocturnal polyuria based on data from frequency-volume charts. Methods Seventeen pre-specified search terms identified 351 unique investigations published from 1990 to 2016 in BIOSIS, Embase, Embase Alerts, International Pharmaceutical Abstract, Medline, and Cochrane. Thirteen original communications were included in this review based on pre-specified exclusion criteria. Data were extracted from each paper regarding subject age, sex, ethnicity, health status, sample size, data collection methods, and diagnostic discrimination of proposed definitions including sensitivity, specificity, positive and negative predictive value. Results The sample size of study cohorts, participant age, sex, ethnicity, and health status varied considerably in 13 studies reporting on the diagnostic performance of seven different definitions of nocturnal polyuria using frequency-volume chart data from 4968 participants. Most study cohorts were small, mono-ethnic, including only Caucasian males aged 50 or higher with primary or secondary polyuria that were compared to a control group of healthy men without nocturia in prospective or retrospective settings. Proposed definitions had poor discriminatory accuracy in evaluations based on data from subjects independent from the original study cohorts with findings being similar regarding the most widely evaluated definition endorsed by ICS. Conclusions Diagnostic performance characteristics for proposed definitions of nocturnal polyuria show poor to modest discrimination and are not based on sufficient level of evidence from representative, multi-ethnic population-based data from both females and males of all adult ages.

Diagnostic yield of 90-kVp low-tube-voltage carotid and intracerebral CT-angiography: effects on radiation dose, image quality and diagnostic performance for the detection of carotid stenosis.

PubMed

Leithner, Doris; Wichmann, Julian L; Mahmoudi, Scherwin; Martin, Simon S; Albrecht, Moritz H; Vogl, Thomas J; Scholtz, Jan-Erik

2018-06-01

To investigate the impact of low-tube-voltage 90-kVp acquisition combined with advanced modeled iterative reconstruction algorithm (Admire) on radiation exposure, image quality, artifacts, and assessment of stenosis in carotid and intracranial CT angiography (CTA). Dual-energy CTA studies of 43 patients performed on a third-generation 192-slice dual-source CT were retrospectively evaluated. Intraindividual comparison of 90-kVp and linearly blended 120-kVp equivalent image series (M_0.6, 60% 90-kVp, 40% Sn-150-kVp) was performed. Contrast-to-noise and signal-to-noise ratios of common carotid artery, internal carotid artery, middle cerebral artery, and basilar artery were calculated. Qualitative image analysis included evaluation of artifacts and suitability for angiographical assessment at shoulder level, carotid bifurcation, siphon, and intracranial by three independent radiologists. Detection and quantification of carotid stenosis were performed. Radiation dose was expressed as dose-length product (DLP). Contrast-to-noise values of all arteries were significantly increased in 90-kVp compared to M_0.6 (p < 0.001). Suitability for angiographical evaluation was rated excellent with low artifacts for all levels in both image series. Both 90-kVp and M_0.6 showed excellent accordance for detection and grading of carotid stenosis with almost perfect interobserver agreement (carotid stenoses in 32 of 129 segments; intraclass correlation coefficient, 0.94). dose-length product was reduced by 40.3% in 90-kVp (110.6 ± 32.1 vs 185.4 ± 47.5 mGy·cm, p < 0.001). 90-kVp carotid and intracranial CTA with Admire provides increased quantitative and similarly good qualitative image quality, while reducing radiation exposure substantially compared to M_0.6. Diagnostic performance for arterial stenosis detection and quantification remained excellent. Advances in knowledge: 90-kVp carotid and intracranial CTA with an advanced iterative reconstruction algorithm results in excellent image quality and reduction of radiation exposure without limiting diagnostic performance.

Use of Capillary Blood Samples Leads to Higher Parasitemia Estimates and Higher Diagnostic Sensitivity of Microscopic and Molecular Diagnostics of Malaria than Venous Blood Samples.

PubMed

Mischlinger, Johannes; Pitzinger, Paul; Veletzky, Luzia; Groger, Mirjam; Zoleko-Manego, Rella; Adegnika, Ayola A; Agnandji, Selidji T; Lell, Bertrand; Kremsner, Peter G; Tannich, Egbert; Mombo-Ngoma, Ghyslain; Mordmüller, Benjamin; Ramharter, Michael

2018-05-25

Diagnosis of malaria is usually based on samples of peripheral blood. However, it is unclear whether capillary (CAP) or venous (VEN) blood samples provide better diagnostic performance. Quantitative differences of parasitemia between CAP and VEN blood and diagnostic performance characteristics were investigated. Patients were recruited between September 2015 and February 2016 in Gabon. Light microscopy and qPCR quantified parasitemia of paired CAP and VEN samples, whose preparation followed the exact same methodology. CAP and VEN performance characteristics using microscopy were evaluated against a qPCR gold-standard. Microscopy revealed a median (IQR) parasites/L of 495 (853,243) in CAP and 429 (524,074) in VEN samples manifesting in a +16.6% (p=0.04) higher CAPparasitemia compared with VENparasitemia. Concordantly, qPCR demonstrated that -0.278 (p=0.006) cycles were required for signal detection in CAP samples. CAPsensitivity of microscopy relative to the gold-standard was 81.5% (77.485.6%) versus VENsensitivity of 73.4% (68.878.1%), while CAPspecificity and VENspecificity were 91%. CAPsensitivity and VENsensitivity dropped to 63.3% and 45.9%, respectively for a sub-population of low-level parasitemias while specificities were 92%. CAP sampling leads to higher parasitemias compared to VEN sampling and improves diagnostic sensitivity. These findings may have important implications for routine diagnostics, research and elimination campaigns of malaria.

Diagnostic precision of mentally estimated home blood pressure means.

PubMed

Ouattara, Franck Olivier; Laskine, Mikhael; Cheong, Nathalie Ng; Birnbaum, Leora; Wistaff, Robert; Bertrand, Michel; van Nguyen, Paul; Kolan, Christophe; Durand, Madeleine; Rinfret, Felix; Lamarre-Cliche, Maxime

2018-05-07

Paper home blood pressure (HBP) charts are commonly brought to physicians at office visits. The precision and accuracy of mental calculations of blood pressure (BP) means are not known. A total of 109 hypertensive patients were instructed to measure and record their HBP for 1 week and to bring their paper charts to their office visit. Study section 1: HBP means were calculated electronically and compared to corresponding in-office BP estimates made by physicians. Study section 2: 100 randomly ordered HBP charts were re-examined repetitively by 11 evaluators. Each evaluator estimated BP means four times in 5, 15, 30, and 60 s (random order) allocated for the task. BP means and diagnostic performance (determination of therapeutic systolic and diastolic BP goals attained or not) were compared between physician estimates and electronically calculated results. Overall, electronically and mentally calculated BP means were not different. Individual analysis showed that 83% of in-office physician estimates were within a 5-mmHg systolic BP range. There was diagnostic disagreement in 15% of cases. Performance improved consistently when the time allocated for BP estimation was increased from 5 to 15 s and from 15 to 30 s, but not when it exceeded 30 s. Mentally calculating HBP means from paper charts can cause a number of diagnostic errors. Chart evaluation exceeding 30 s does not significantly improve accuracy. BP-measuring devices with modern analytical capacities could be useful to physicians.

Performance of the High-Energy Single-Event Effects Test Facility (SEETF) at Michigan State University's National Superconducting Cyclotron Laboratory (NSCL)

NASA Technical Reports Server (NTRS)

Ladbury, R.; Reed, R. A.; Marshall, P. W.; LaBel, K. A.; Anantaraman, R.; Fox, R.; Sanderson, D. P.; Stolz, A.; Yurkon, J.; Zeller, A. F.;

ASSESSING UST CORRECTIVE ACTION TECHNOLOGIES: DIAGNOSTIC EVALUATION OF IN SITU SVE-BASED SYSTEM PERFORMANCE

EPA Science Inventory

In situ corrective action technologies are being proposed and installed at an increasing number of underground storage tank (LIST) sites contaminated with petroleum products in saturated and unsaturated zones. It is often difficult to accurately assess the performance of these sy...

Beamlet diagnostics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Theys, M.

1994-05-06

Beamlet is a high power laser currently being built at Lawrence Livermore National Lab as a proof of concept for the National Ignition Facility (NIF). Beamlet is testing several areas of laser advancements, such as a 37cm Pockels cell, square amplifier, and propagation of a square beam. The diagnostics on beamlet tell the operators how much energy the beam has in different locations, the pulse shape, the energy distribution, and other important information regarding the beam. This information is being used to evaluate new amplifier designs, and extrapolate performance to the NIF laser. In my term at Lawrence Livermore Nationalmore » Laboratory I have designed and built a diagnostic, calibrated instruments used on diagnostics, setup instruments, hooked up communication lines to the instruments, and setup computers to control specific diagnostics.« less

Built-In-Test Equipment Requirements Workshop. Workshop Presentation

DTIC Science & Technology

1981-08-01

quantitatively evaluated in test. (2) It is necessary to develop the statistical methods that should be used for predicting and confirming of diagnostic...of different performance levels of BIT peacetime and wartime applications, and the corresponding manpower and other support requirements should be...reports. The scope of the workshop involves the areas of require- ments for built-in-test and diagnostics, and the methods of testing to ensure that the

Diagnostic capability of spectral-domain optical coherence tomography for glaucoma.

PubMed

Wu, Huijuan; de Boer, Johannes F; Chen, Teresa C

2012-05-01

To determine the diagnostic capability of spectral-domain optical coherence tomography in glaucoma patients with visual field defects. Prospective, cross-sectional study. Participants were recruited from a university hospital clinic. One eye of 85 normal subjects and 61 glaucoma patients with average visual field mean deviation of -9.61 ± 8.76 dB was selected randomly for the study. A subgroup of the glaucoma patients with early visual field defects was calculated separately. Spectralis optical coherence tomography (Heidelberg Engineering, Inc) circular scans were performed to obtain peripapillary retinal nerve fiber layer (RNFL) thicknesses. The RNFL diagnostic parameters based on the normative database were used alone or in combination for identifying glaucomatous RNFL thinning. To evaluate diagnostic performance, calculations included areas under the receiver operating characteristic curve, sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio. Overall RNFL thickness had the highest area under the receiver operating characteristic curve values: 0.952 for all patients and 0.895 for the early glaucoma subgroup. For all patients, the highest sensitivity (98.4%; 95% confidence interval, 96.3% to 100%) was achieved by using 2 criteria: ≥ 1 RNFL sectors being abnormal at the < 5% level and overall classification of borderline or outside normal limits, with specificities of 88.9% (95% confidence interval, 84.0% to 94.0%) and 87.1% (95% confidence interval, 81.6% to 92.5%), respectively, for these 2 criteria. Statistical parameters for evaluating the diagnostic performance of the Spectralis spectral-domain optical coherence tomography were good for early perimetric glaucoma and were excellent for moderately advanced perimetric glaucoma. Copyright © 2012 Elsevier Inc. All rights reserved.

[Evaluation of upper cervical spine injury (C1-C2) with computed tomography].

PubMed

Siemianowicz, Anna; Baron, Jan; Wawrzynek, Wojciech; Koczy, Bogdan; Kasprowska, Sabina

2006-01-01

Cervical spine injuries are common and essential diagnostic problem. Diagnostic imaging is necessary for proper and effective treatment. Helical computed tomography (CT) and plain radiography are the basic diagnostic methods in cervical spine injuries. The purpose of this work was the comparison of CT examination of the upper cervical spine (CI-C2) with patients' clinical state. Twenty four patients (17 men and 7 women) were introduced into the study. The most common cause of cervical spine injuries were car accidents (48.5%). CT examination was performed in all patients. Six patients (25%) had multilevel injury, localized at C1-C2 level and in the lower part of cervical spine. The main pathology diagnosed by CT in the studied group was rotatory subluxation (66.6%). Eight patients (33.3%), with rotatory subluxation did not present any abnormalities in neurological examination performed immediately after the admission to the hospital. C1 and/or C2 fractures were diagnosed in 11 patients (45.8%), in some cases (in 3 patients - 12.5%) they were accompanied by rotatory subluxations. CT examination is the basic technique of diagnostic imaging in a case of cervical spine injuries. It enables quick, accurate and precise evaluation of bone structures and surrounding soft tissues. CT also enables multiplanar imaging and 3-dimentional imaging.

The methodological quality of diagnostic test accuracy studies for musculoskeletal conditions can be improved.

PubMed

Henschke, Nicholas; Keuerleber, Julia; Ferreira, Manuela; Maher, Christopher G; Verhagen, Arianne P

2014-04-01

To provide an overview of reporting and methodological quality in diagnostic test accuracy (DTA) studies in the musculoskeletal field and evaluate the use of the QUality Assessment of Diagnostic Accuracy Studies (QUADAS) checklist. A literature review identified all systematic reviews that evaluated the accuracy of clinical tests to diagnose musculoskeletal conditions and used the QUADAS checklist. Two authors screened all identified reviews and extracted data on the target condition, index tests, reference standard, included studies, and QUADAS items. A descriptive analysis of the QUADAS checklist was performed, along with Rasch analysis to examine the construct validity and internal reliability. A total of 19 systematic reviews were included, which provided data on individual items of the QUADAS checklist for 392 DTA studies. In the musculoskeletal field, uninterpretable or intermediate test results are commonly not reported, with 175 (45%) studies scoring "no" to this item. The proportion of studies fulfilling certain items varied from 22% (item 11) to 91% (item 3). The interrater reliability of the QUADAS checklist was good and Rasch analysis showed excellent construct validity and internal consistency. This overview identified areas where the reporting and performance of diagnostic studies within the musculoskeletal field can be improved. Copyright © 2014 Elsevier Inc. All rights reserved.

Occupational exposure to mineral turpentine and heavy fuels: a possible risk factor for Alzheimer's disease.

PubMed

Helou, Rafik; Jaecker, Pierre

2014-05-01

The association between solvents and Alzheimer's disease (AD) has been the subject of several studies. Yet, only few studies have examined the various solvents separately, and the controls have rarely been monitored long enough. For these reasons and others, we believe that further studies are required. The objective of this study was to identify solvents associated with the clinicoradiological diagnostic of AD or mixed-type dementia (MD). A retrospective case-control study was performed in 156 patients followed up at the Memory Diagnostic Center of Bertinot Juel Hospital (France). The inclusion criteria were known occupation(s), a Mini-Mental State Examination (MMSE) score ≥10 at the first visit, a neuropsychological evaluation performed and a diagnosis established in our Memory Diagnostic Center. The diagnostics were crossed with 9 solvents belonging to two classes of solvents. Exposure was evaluated using French national job-exposure matrices. Certain petroleum-based solvents and fuels (i.e. mineral turpentine, diesel fuel, fuel oil and kerosene) were associated with a diagnosis of AD or MD. This association was still significant after adjustment for age, sex and education (adjusted OR: 6.5; 95% CI: 2-20). Occupational exposure to mineral turpentine and heavy fuels may be a risk factor for AD and MD.

Ruling Out Brain CT Contraindications prior to Intravenous Thrombolysis: Diagnostic Equivalence between a Primary Interpretation Workstation and a Mobile Tablet Computer.

PubMed

Salazar, Antonio J; Useche, Nicolás; Granja, Manuel; Morillo, Aníbal J; Bermúdez, Sonia

2017-01-01

The aim of this study was to evaluate the equivalence of brain CT interpretations performed using a diagnostic workstation and a mobile tablet computer, in a telestroke service. The ethics committee of our institution approved this retrospective study. A factorial design with 1452 interpretations was used. The assessed variables were the type of stroke classification, the presence of contraindications to the tPA administration, the presence of a hyperdense intracranial artery sign (HMCA), and the Alberta Stroke Program Early CT Score (ASPECTS) score. These variables were evaluated to determine the effect that the reading system had on their magnitudes. The achieved distribution of observed lesions using both the reading systems was not statistically different. The differences between the two reading systems to claim equivalence were 1.6% for hemorrhagic lesions, 4.5% for cases without lesion, and 5.2 for overall ischemic lesion. Equivalence was achieved at 2.1% for ASPECTS ≤ 6, 6.5% for the presence of imaging contraindication to the tPA administration, and 7.2% for the presence of HMCA. The diagnostic performance for detecting acute stroke is likely equivalent whether a tablet computer or a diagnostic workstation is used or not.

Ruling Out Brain CT Contraindications prior to Intravenous Thrombolysis: Diagnostic Equivalence between a Primary Interpretation Workstation and a Mobile Tablet Computer

PubMed Central

Useche, Nicolás; Granja, Manuel; Morillo, Aníbal J.; Bermúdez, Sonia

2017-01-01

Objective The aim of this study was to evaluate the equivalence of brain CT interpretations performed using a diagnostic workstation and a mobile tablet computer, in a telestroke service. Materials and Methods The ethics committee of our institution approved this retrospective study. A factorial design with 1452 interpretations was used. The assessed variables were the type of stroke classification, the presence of contraindications to the tPA administration, the presence of a hyperdense intracranial artery sign (HMCA), and the Alberta Stroke Program Early CT Score (ASPECTS) score. These variables were evaluated to determine the effect that the reading system had on their magnitudes. Results The achieved distribution of observed lesions using both the reading systems was not statistically different. The differences between the two reading systems to claim equivalence were 1.6% for hemorrhagic lesions, 4.5% for cases without lesion, and 5.2 for overall ischemic lesion. Equivalence was achieved at 2.1% for ASPECTS ≤ 6, 6.5% for the presence of imaging contraindication to the tPA administration, and 7.2% for the presence of HMCA. Conclusion The diagnostic performance for detecting acute stroke is likely equivalent whether a tablet computer or a diagnostic workstation is used or not. PMID:29250111

Performance evaluation of Sanger sequencing for the diagnosis of primary hyperoxaluria and comparison with targeted next generation sequencing

PubMed Central

Williams, Emma L; Bagg, Eleanor A L; Mueller, Michael; Vandrovcova, Jana; Aitman, Timothy J; Rumsby, Gill

2015-01-01

Definitive diagnosis of primary hyperoxaluria (PH) currently utilizes sequential Sanger sequencing of the AGXT, GRPHR, and HOGA1 genes but efficacy is unproven. This analysis is time-consuming, relatively expensive, and delays in diagnosis and inappropriate treatment can occur if not pursued early in the diagnostic work-up. We reviewed testing outcomes of Sanger sequencing in 200 consecutive patient samples referred for analysis. In addition, the Illumina Truseq custom amplicon system was evaluated for paralleled next-generation sequencing (NGS) of AGXT,GRHPR, and HOGA1 in 90 known PH patients. AGXT sequencing was requested in all patients, permitting a diagnosis of PH1 in 50%. All remaining patients underwent targeted exon sequencing of GRHPR and HOGA1 with 8% diagnosed with PH2 and 8% with PH3. Complete sequencing of both GRHPR and HOGA1 was not requested in 25% of patients referred leaving their diagnosis in doubt. NGS analysis showed 98% agreement with Sanger sequencing and both approaches had 100% diagnostic specificity. Diagnostic sensitivity of Sanger sequencing was 98% and for NGS it was 97%. NGS has comparable diagnostic performance to Sanger sequencing for the diagnosis of PH and, if implemented, would screen for all forms of PH simultaneously ensuring prompt diagnosis at decreased cost. PMID:25629080

A One-Versus-All Class Binarization Strategy for Bearing Diagnostics of Concurrent Defects

PubMed Central

Ng, Selina S. Y.; Tse, Peter W.; Tsui, Kwok L.

2014-01-01

In bearing diagnostics using a data-driven modeling approach, a concern is the need for data from all possible scenarios to build a practical model for all operating conditions. This paper is a study on bearing diagnostics with the concurrent occurrence of multiple defect types. The authors are not aware of any work in the literature that studies this practical problem. A strategy based on one-versus-all (OVA) class binarization is proposed to improve fault diagnostics accuracy while reducing the number of scenarios for data collection, by predicting concurrent defects from training data of normal and single defects. The proposed OVA diagnostic approach is evaluated with empirical analysis using support vector machine (SVM) and C4.5 decision tree, two popular classification algorithms frequently applied to system health diagnostics and prognostics. Statistical features are extracted from the time domain and the frequency domain. Prediction performance of the proposed strategy is compared with that of a simple multi-class classification, as well as that of random guess and worst-case classification. We have verified the potential of the proposed OVA diagnostic strategy in performance improvements for single-defect diagnosis and predictions of BPFO plus BPFI concurrent defects using two laboratory-collected vibration data sets. PMID:24419162

A one-versus-all class binarization strategy for bearing diagnostics of concurrent defects.

PubMed

Ng, Selina S Y; Tse, Peter W; Tsui, Kwok L

2014-01-13

In bearing diagnostics using a data-driven modeling approach, a concern is the need for data from all possible scenarios to build a practical model for all operating conditions. This paper is a study on bearing diagnostics with the concurrent occurrence of multiple defect types. The authors are not aware of any work in the literature that studies this practical problem. A strategy based on one-versus-all (OVA) class binarization is proposed to improve fault diagnostics accuracy while reducing the number of scenarios for data collection, by predicting concurrent defects from training data of normal and single defects. The proposed OVA diagnostic approach is evaluated with empirical analysis using support vector machine (SVM) and C4.5 decision tree, two popular classification algorithms frequently applied to system health diagnostics and prognostics. Statistical features are extracted from the time domain and the frequency domain. Prediction performance of the proposed strategy is compared with that of a simple multi-class classification, as well as that of random guess and worst-case classification. We have verified the potential of the proposed OVA diagnostic strategy in performance improvements for single-defect diagnosis and predictions of BPFO plus BPFI concurrent defects using two laboratory-collected vibration data sets.

Noninvasive prostate cancer screening based on serum surface-enhanced Raman spectroscopy and support vector machine

NASA Astrophysics Data System (ADS)

Li, Shaoxin; Zhang, Yanjiao; Xu, Junfa; Li, Linfang; Zeng, Qiuyao; Lin, Lin; Guo, Zhouyi; Liu, Zhiming; Xiong, Honglian; Liu, Songhao

2014-09-01

This study aims to present a noninvasive prostate cancer screening methods using serum surface-enhanced Raman scattering (SERS) and support vector machine (SVM) techniques through peripheral blood sample. SERS measurements are performed using serum samples from 93 prostate cancer patients and 68 healthy volunteers by silver nanoparticles. Three types of kernel functions including linear, polynomial, and Gaussian radial basis function (RBF) are employed to build SVM diagnostic models for classifying measured SERS spectra. For comparably evaluating the performance of SVM classification models, the standard multivariate statistic analysis method of principal component analysis (PCA) is also applied to classify the same datasets. The study results show that for the RBF kernel SVM diagnostic model, the diagnostic accuracy of 98.1% is acquired, which is superior to the results of 91.3% obtained from PCA methods. The receiver operating characteristic curve of diagnostic models further confirm above research results. This study demonstrates that label-free serum SERS analysis technique combined with SVM diagnostic algorithm has great potential for noninvasive prostate cancer screening.

Development of a diagnostic diagram for rapid field assessment of acidosis severity in diarrheic calves.

PubMed

Bellino, Claudio; Arnaudo, Fabrizio; Biolatti, Cristina; Borrelli, Antonio; Gianella, Paola; Maurella, Cristiana; Zabaldano, Giuseppe; Cagnasso, Aurelio; D'Angelo, Antonio

2012-02-01

To develop a diagnostic diagram for rapid field assessment of acidosis severity in diarrheic calves. Prospective cross-sectional study. 148 Piedmontese calves (38 calves in preliminary experiments; 83 diarrheic calves and 27 healthy control calves in the primary experiment). Physical examination was performed and a standard data collection form was completed for each calf. Blood samples were obtained and submitted for evaluation of acid-base balance, performance of a CBC, and measurement of electrolyte and total protein concentrations. Severe metabolic acidosis (extracellular base excess more negative than -10 mmol/L) was associated with abnormal mental status, delayed or absent suckle reflex, abnormal posture or gait, enophthalmos, and cold oral mucosal membranes. Clinical signs associated with severe metabolic acidosis were arranged into a grid to create a diagnostic diagram. Sensitivity and specificity of the diagnostic diagram for the prediction of severe metabolic acidosis were 88% and 79%, respectively. Use of the diagnostic diagram may aid differentiation between severe and nonsevere acidosis patterns as determined on the basis of clinical signs.

An examination of the relationships between physicians' clinical and hospital-utilization performance.

PubMed Central

Saywell, R M; Bean, J A; Ludke, R L; Redman, R W; McHugh, G J

1981-01-01

To examine the relationships between measures of attending physician teams' clinical and utilization performance, inpatient hospital audits were conducted in 22 Maryland and western Pennsylvania nonfederal short-term hospitals. A total of 6,980 medical records were abstracted from eight diagnostic categories using the Payne and JCAH PEP medical audit procedures. The results indicate weak statistical associations between the two medical care evaluation audits; between clinical performance and utilization performance, as measured by appropriateness of admissions and length of stay; and between three utilization measures. Based on these findings, it does not appear valid to use performance in one area to evaluate performance in the other in order to measure or evaluate and ultimately improve physicians; clinical or utilization performance. PMID:6946048

Value of physical tests in diagnosing cervical radiculopathy: a systematic review.

PubMed

Thoomes, Erik J; van Geest, Sarita; van der Windt, Danielle A; Falla, Deborah; Verhagen, Arianne P; Koes, Bart W; Thoomes-de Graaf, Marloes; Kuijper, Barbara; Scholten-Peeters, Wendy G M; Vleggeert-Lankamp, Carmen L

2018-01-01

In clinical practice, the diagnosis of cervical radiculopathy is based on information from the patient's history, physical examination, and diagnostic imaging. Various physical tests may be performed, but their diagnostic accuracy is unknown. This study aimed to summarize and update the evidence on diagnostic performance of tests carried out during a physical examination for the diagnosis of cervical radiculopathy. A review of the accuracy of diagnostic tests was carried out. The study sample comprised diagnostic studies comparing results of tests performed during a physical examination in diagnosing cervical radiculopathy with a reference standard of imaging or surgical findings. Sensitivity, specificity, likelihood ratios are presented, together with pooled results for sensitivity and specificity. A literature search up to March 2016 was performed in CENTRAL, PubMed (MEDLINE), Embase, CINAHL, Web of Science, and Google Scholar. The methodological quality of studies was assessed using the QUADAS-2. Five diagnostic accuracy studies were identified. Only Spurling's test was evaluated in more than one study, showing high specificity ranging from 0.89 to 1.00 (95% confidence interval [CI]: 0.59-1.00); sensitivity varied from 0.38 to 0.97 (95% CI: 0.21-0.99). No studies were found that assessed the diagnostic accuracy of widely used neurological tests such as key muscle strength, tendon reflexes, and sensory impairments. There is limited evidence for accuracy of physical examination tests for the diagnosis of cervical radiculopathy. When consistent with patient history, clinicians may use a combination of Spurling's, axial traction, and an Arm Squeeze test to increase the likelihood of a cervical radiculopathy, whereas a combined results of four negative neurodynamics tests and an Arm Squeeze test could be used to rule out the disorder. Copyright © 2017 Elsevier Inc. All rights reserved.

Diagnostic Accuracy of Computer Tomography Angiography and Magnetic Resonance Angiography in the Stenosis Detection of Autologuous Hemodialysis Access: A Meta-Analysis

PubMed Central

Liu, Shiyuan

2013-01-01

Purpose To compare the diagnostic performances of computer tomography angiography (CTA) and magnetic resonance angiography (MRA) for detection and assessment of stenosis in patients with autologuous hemodialysis access. Materials and Methods Search of PubMed, MEDLINE, EMBASE and Cochrane Library database from January 1984 to May 2013 for studies comparing CTA or MRA with DSA or surgery for autologuous hemodialysis access. Eligible studies were in English language, aimed to detect more than 50% stenosis or occlusion of autologuous vascular access in hemodialysis patients with CTA and MRA technology and provided sufficient data about diagnosis performance. Methodological quality was assessed by the Quality Assessment of Diagnostic Studies (QUADAS) instrument. Sensitivities (SEN), specificities (SPE), positive likelihood ratio (PLR), negative likelihood values (NLR), diagnostic odds ratio (DOR) and areas under the receiver operator characteristic curve (AUC) were pooled statistically. Potential threshold effect, heterogeneity and publication bias was evaluated. The clinical utility of CTA and MRA in detection of stenosis was also investigated. Result Sixteen eligible studies were included, with a total of 500 patients. Both CTA and MRA were accurate modality (sensitivity, 96.2% and 95.4%, respectively; specificity, 97.1 and 96.1%, respectively; DOR [diagnostic odds ratio], 393.69 and 211.47, respectively) for hemodialysis vascular access. No significant difference was detected between the diagnostic performance of CTA (AUC, 0.988) and MRA (AUC, 0.982). Meta-regression analyses and subgroup analyses revealed no statistical difference. The Deek’s funnel plots suggested a publication bias. Conclusion Diagnostic performance of CTA and MRA for detecting stenosis of hemodialysis vascular access had no statistical difference. Both techniques may function as an alternative or an important complement to conventional digital subtraction angiography (DSA) and may be able to help guide medical management. PMID:24194928

Evaluation of shear wave elastography for differential diagnosis of breast lesions: A new qualitative analysis versus conventional quantitative analysis.

PubMed

Ren, Wei-Wei; Li, Xiao-Long; Wang, Dan; Liu, Bo-Ji; Zhao, Chong-Ke; Xu, Hui-Xiong

2018-04-13

To evaluate a special kind of ultrasound (US) shear wave elastography for differential diagnosis of breast lesions, using a new qualitative analysis (i.e. the elasticity score in the travel time map) compared with conventional quantitative analysis. From June 2014 to July 2015, 266 pathologically proven breast lesions were enrolled in this study. The maximum, mean, median, minimum, and standard deviation of shear wave speed (SWS) values (m/s) were assessed. The elasticity score, a new qualitative feature, was evaluated in the travel time map. The area under the receiver operating characteristic (AUROC) curves were plotted to evaluate the diagnostic performance of both qualitative and quantitative analyses for differentiation of breast lesions. Among all quantitative parameters, SWS-max showed the highest AUROC (0.805; 95% CI: 0.752, 0.851) compared with SWS-mean (0.786; 95% CI:0.732, 0.834; P = 0.094), SWS-median (0.775; 95% CI:0.720, 0.824; P = 0.046), SWS-min (0.675; 95% CI:0.615, 0.731; P = 0.000), and SWS-SD (0.768; 95% CI:0.712, 0.817; P = 0.074). The AUROC of qualitative analysis in this study obtained the best diagnostic performance (0.871; 95% CI: 0.825, 0.909, compared with the best parameter of SWS-max in quantitative analysis, P = 0.011). The new qualitative analysis of shear wave travel time showed the superior diagnostic performance in the differentiation of breast lesions in comparison with conventional quantitative analysis.

Physical evaluation of color and monochrome medical displays using an imaging colorimeter

NASA Astrophysics Data System (ADS)

Roehrig, Hans; Gu, Xiliang; Fan, Jiahua

2013-03-01

This paper presents an approach to physical evaluation of color and monochrome medical grade displays using an imaging colorimeter. The purpose of this study was to examine the influence of medical display types, monochrome or color at the same maximum luminance settings, on diagnostic performance. The focus was on the measurements of physical characteristics including spatial resolution and noise performance, which we believed could affect the clinical performance. Specifically, Modulation Transfer Function (MTF) and Noise Power Spectrum (NPS) were evaluated and compared at different digital driving levels (DDL) between two EIZO displays.

Comparison of 21-gauge and 22-gauge aspiration needle in endobronchial ultrasound-guided transbronchial needle aspiration: results of the American College of Chest Physicians Quality Improvement Registry, Education, and Evaluation Registry.

PubMed

Yarmus, Lonny B; Akulian, Jason; Lechtzin, Noah; Yasin, Faiza; Kamdar, Biren; Ernst, Armin; Ost, David E; Ray, Cynthia; Greenhill, Sarah R; Jimenez, Carlos A; Filner, Joshua; Feller-Kopman, David

2013-04-01

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive procedure originally performed using a 22-gauge (22G) needle. A recently introduced 21-gauge (21G) needle may improve the diagnostic yield and sample adequacy of EBUS-TBNA, but prior smaller studies have shown conflicting results. To our knowledge, this is the largest study undertaken to date to determine whether the 21G needle adds diagnostic benefit. We retrospectively evaluated the results of 1,299 patients from the American College of Chest Physicians Quality Improvement Registry, Education, and Evaluation (AQuIRE) Diagnostic Registry who underwent EBUS-TBNA between February 2009 and September 2010 at six centers throughout the United States. Data collection included patient demographics, sample adequacy, and diagnostic yield. Analysis consisted of univariate and multivariate hierarchical logistic regression comparing diagnostic yield and sample adequacy of EBUS-TBNA specimens by needle gauge. A total of 1,235 patients met inclusion criteria. Sample adequacy was obtained in 94.9% of the 22G needle group and in 94.6% of the 21G needle group (P = .81). A diagnosis was made in 51.4% of the 22G and 51.3% of the 21G groups (P = .98). Multivariate hierarchical logistic regression showed no statistical difference in sample adequacy or diagnostic yield between the two groups. The presence of rapid onsite cytologic evaluation was associated with significantly fewer needle passes per procedure when using the 21G needle (P < .001). There is no difference in specimen adequacy or diagnostic yield between the 21G and 22G needle groups. EBUS-TBNA in conjunction with rapid onsite cytologic evaluation and a 21G needle is associated with fewer needle passes compared with a 22G needle.

Diagnostic Assessment of Deep Learning Algorithms for Detection of Lymph Node Metastases in Women With Breast Cancer.

PubMed

Ehteshami Bejnordi, Babak; Veta, Mitko; Johannes van Diest, Paul; van Ginneken, Bram; Karssemeijer, Nico; Litjens, Geert; van der Laak, Jeroen A W M; Hermsen, Meyke; Manson, Quirine F; Balkenhol, Maschenka; Geessink, Oscar; Stathonikos, Nikolaos; van Dijk, Marcory Crf; Bult, Peter; Beca, Francisco; Beck, Andrew H; Wang, Dayong; Khosla, Aditya; Gargeya, Rishab; Irshad, Humayun; Zhong, Aoxiao; Dou, Qi; Li, Quanzheng; Chen, Hao; Lin, Huang-Jing; Heng, Pheng-Ann; Haß, Christian; Bruni, Elia; Wong, Quincy; Halici, Ugur; Öner, Mustafa Ümit; Cetin-Atalay, Rengul; Berseth, Matt; Khvatkov, Vitali; Vylegzhanin, Alexei; Kraus, Oren; Shaban, Muhammad; Rajpoot, Nasir; Awan, Ruqayya; Sirinukunwattana, Korsuk; Qaiser, Talha; Tsang, Yee-Wah; Tellez, David; Annuscheit, Jonas; Hufnagl, Peter; Valkonen, Mira; Kartasalo, Kimmo; Latonen, Leena; Ruusuvuori, Pekka; Liimatainen, Kaisa; Albarqouni, Shadi; Mungal, Bharti; George, Ami; Demirci, Stefanie; Navab, Nassir; Watanabe, Seiryo; Seno, Shigeto; Takenaka, Yoichi; Matsuda, Hideo; Ahmady Phoulady, Hady; Kovalev, Vassili; Kalinovsky, Alexander; Liauchuk, Vitali; Bueno, Gloria; Fernandez-Carrobles, M Milagro; Serrano, Ismael; Deniz, Oscar; Racoceanu, Daniel; Venâncio, Rui

2017-12-12

Application of deep learning algorithms to whole-slide pathology images can potentially improve diagnostic accuracy and efficiency. Assess the performance of automated deep learning algorithms at detecting metastases in hematoxylin and eosin-stained tissue sections of lymph nodes of women with breast cancer and compare it with pathologists' diagnoses in a diagnostic setting. Researcher challenge competition (CAMELYON16) to develop automated solutions for detecting lymph node metastases (November 2015-November 2016). A training data set of whole-slide images from 2 centers in the Netherlands with (n = 110) and without (n = 160) nodal metastases verified by immunohistochemical staining were provided to challenge participants to build algorithms. Algorithm performance was evaluated in an independent test set of 129 whole-slide images (49 with and 80 without metastases). The same test set of corresponding glass slides was also evaluated by a panel of 11 pathologists with time constraint (WTC) from the Netherlands to ascertain likelihood of nodal metastases for each slide in a flexible 2-hour session, simulating routine pathology workflow, and by 1 pathologist without time constraint (WOTC). Deep learning algorithms submitted as part of a challenge competition or pathologist interpretation. The presence of specific metastatic foci and the absence vs presence of lymph node metastasis in a slide or image using receiver operating characteristic curve analysis. The 11 pathologists participating in the simulation exercise rated their diagnostic confidence as definitely normal, probably normal, equivocal, probably tumor, or definitely tumor. The area under the receiver operating characteristic curve (AUC) for the algorithms ranged from 0.556 to 0.994. The top-performing algorithm achieved a lesion-level, true-positive fraction comparable with that of the pathologist WOTC (72.4% [95% CI, 64.3%-80.4%]) at a mean of 0.0125 false-positives per normal whole-slide image. For the whole-slide image classification task, the best algorithm (AUC, 0.994 [95% CI, 0.983-0.999]) performed significantly better than the pathologists WTC in a diagnostic simulation (mean AUC, 0.810 [range, 0.738-0.884]; P < .001). The top 5 algorithms had a mean AUC that was comparable with the pathologist interpreting the slides in the absence of time constraints (mean AUC, 0.960 [range, 0.923-0.994] for the top 5 algorithms vs 0.966 [95% CI, 0.927-0.998] for the pathologist WOTC). In the setting of a challenge competition, some deep learning algorithms achieved better diagnostic performance than a panel of 11 pathologists participating in a simulation exercise designed to mimic routine pathology workflow; algorithm performance was comparable with an expert pathologist interpreting whole-slide images without time constraints. Whether this approach has clinical utility will require evaluation in a clinical setting.

Usefulness of diffusion-weighted MR imaging for differentiating between benign and malignant superficial soft tissue tumours and tumour-like lesions

PubMed Central

Jeon, Ji Young; Lee, Min Hee; Lee, Sang Hoon; Shin, Myung Jin

2016-01-01

Objective: To evaluate the usefulness of adding diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) mapping to conventional 3.0-T MRI to differentiate between benign and malignant superficial soft-tissue masses (SSTMs). Methods: The institutional review board approved this study and informed consent was waived. The authors retrospectively analyzed conventional MR images including diffusion-weighted images (b-values: 0, 400, 800 s mm−2) in 60 histologically proven SSTMs (35 benign and 25 malignant) excluding lipomas. Two radiologists independently evaluated the conventional MRI alone and again with the additional DWI for the evaluation of malignant masses. The mean ADC values measured within an entire mass and the contrast-enhancing solid portion were used for quantitative analysis. Diagnostic performances were compared using receiver-operating characteristic analysis. Results: For an inexperienced reader, using only conventional MRI, the sensitivity, specificity and accuracy were 84%, 80% and 81.6%, respectively. When combining conventional MRI and DWI, the sensitivity, specificity and accuracy were 96%, 85.7% and 90%, respectively. Additional DWI influenced the improvement of the rate of correct diagnosis by 8.3% (5/60). For an experienced reader, additional DWI revealed the same accuracy of 86.7% without added value on the correct diagnosis. The group mean ADCs of malignant SSTMs were significantly lower than that of benign SSTMs (p < 0.001). The best diagnostic performance with respect to differentiation of SSTMs could be obtained when conventional MRI was assessed in combination with DWI. Conclusion: Adding qualitative and quantitative DWI to conventional MRI can improve the diagnostic performance for the differentiation between benign and malignant SSTMs. Advances in knowledge: Because the imaging characteristics of many malignant superficial soft-tissue lesions overlap with those of benign ones, inadequate surgical resection due to misinterpretation of MRI often occurs. Adding DWI to conventional MRI yields greater diagnostic performances [area under the receiver-operating characteristic curve (AUC), 0.83–0.99] than does the use of conventional MRI alone (AUC, 0.71–0.93) in the evaluation of malignant superficial masses by inexperienced readers. PMID:26892266

Benefit-risk Evaluation for Diagnostics: A Framework (BED-FRAME).

PubMed

Evans, Scott R; Pennello, Gene; Pantoja-Galicia, Norberto; Jiang, Hongyu; Hujer, Andrea M; Hujer, Kristine M; Manca, Claudia; Hill, Carol; Jacobs, Michael R; Chen, Liang; Patel, Robin; Kreiswirth, Barry N; Bonomo, Robert A

2016-09-15

The medical community needs systematic and pragmatic approaches for evaluating the benefit-risk trade-offs of diagnostics that assist in medical decision making. Benefit-Risk Evaluation of Diagnostics: A Framework (BED-FRAME) is a strategy for pragmatic evaluation of diagnostics designed to supplement traditional approaches. BED-FRAME evaluates diagnostic yield and addresses 2 key issues: (1) that diagnostic yield depends on prevalence, and (2) that different diagnostic errors carry different clinical consequences. As such, evaluating and comparing diagnostics depends on prevalence and the relative importance of potential errors. BED-FRAME provides a tool for communicating the expected clinical impact of diagnostic application and the expected trade-offs of diagnostic alternatives. BED-FRAME is a useful fundamental supplement to the standard analysis of diagnostic studies that will aid in clinical decision making. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Is Diagnostic Performance of Quantitative 2D-Shear Wave Elastography Optimal for Clinical Classification of Benign and Malignant Thyroid Nodules?: A Systematic Review and Meta-analysis.

PubMed

Nattabi, Haliimah A; Sharif, Norhafidzah M; Yahya, Noorazrul; Ahmad, Rozilawati; Mohamad, Mazlyfarina; Zaki, Faizah M; Yusoff, Ahmad N

2017-10-17

This study is a dedicated 2D-shear wave elastography (2D-SWE) review aimed at systematically eliciting up-to-date evidence of its clinical value in differential diagnosis of benign and malignant thyroid nodules. PubMed, Web of Science, and Scopus databases were searched for studies assessing the diagnostic value of 2D-SWE for thyroid malignancy risk stratification published until December 2016. The retrieved titles and abstracts were screened and evaluated according to the predefined inclusion and exclusion criteria. Methodological quality of the studies was assessed using the Quality Assessment of Studies of Diagnostic Accuracy included in Systematic Review 2 (QUADAS-2) tool. Extracted 2D-SWE diagnostic performance data were meta-analyzed to assess the summary sensitivity, specificity, and area under the receiver operating characteristic curve. After stepwise review, 14 studies in which 2D-SWE was used to evaluate 2851 thyroid nodules (1092 malignant, 1759 benign) from 2139 patients were selected for the current study. Study quality on QUADAS-2 assessment was moderate to high. The summary sensitivity, specificity and area under the receiver operating characteristic curve of 2D-SWE for differential diagnosis of benign and malignant thyroid nodules were 0.66 (95% confidence interval [CI]: 0.64-0.69), 0.78 (CI: 0.76-0.80), and 0.851 (Q* = 0.85), respectively. The pooled diagnostic odds ratio, negative likelihood ratio, and positive likelihood ratio were 12.73 (CI: 8.80-18.43), 0.31 (CI: 0.22-0.44), and 3.87 (CI: 2.83-5.29), respectively. Diagnostic performance of quantitative 2D-SWE for malignancy risk stratification of thyroid nodules is suboptimal with mediocre sensitivity and specificity, contrary to earlier reports of excellence. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

No added diagnostic value of non-phosphorylated tau fraction (p-taurel) in CSF as a biomarker for differential dementia diagnosis.

PubMed

Goossens, Joery; Bjerke, Maria; Struyfs, Hanne; Niemantsverdriet, Ellis; Somers, Charisse; Van den Bossche, Tobi; Van Mossevelde, Sara; De Vil, Bart; Sieben, Anne; Martin, Jean-Jacques; Cras, Patrick; Goeman, Johan; De Deyn, Peter Paul; Van Broeckhoven, Christine; van der Zee, Julie; Engelborghs, Sebastiaan

2017-07-14

The Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarkers Aβ 1-42 , t-tau, and p-tau 181 overlap with other diseases. New tau modifications or epitopes, such as the non-phosphorylated tau fraction (p-tau rel ), may improve differential dementia diagnosis. The goal of this study is to investigate if p-tau rel can improve the diagnostic performance of the AD CSF biomarker panel for differential dementia diagnosis. The study population consisted of 45 AD, 45 frontotemporal lobar degeneration (FTLD), 45 dementia with Lewy bodies (DLB), and 21 Creutzfeldt-Jakob disease (CJD) patients, and 20 cognitively healthy controls. A substantial subset of the patients was pathology-confirmed. CSF levels of Aβ 1-42 , t-tau, p-tau 181 , and p-tau rel were determined with commercially available single-analyte enzyme-linked immunosorbent assay (ELISA) kits. Diagnostic performance was evaluated by receiver operating characteristic (ROC) curve analyses, and area under the curve (AUC) values were compared using DeLong tests. The diagnostic performance of single markers as well as biomarker ratios was determined for each pairwise comparison of different dementia groups and controls. The addition of p-tau rel to the AD biomarker panel decreased its diagnostic performance when discriminating non-AD, FTLD, and DLB from AD. As a single marker, p-tau rel increased the diagnostic performance for CJD. No significant difference was found in AUC values with the addition of p-tau rel when differentiating between AD or non-AD dementias and controls. The addition of p-tau rel to the AD CSF biomarker panel failed to improve differentiation between AD and non-AD dementias.

Sonography of the chest using linear-array versus sector transducers: Correlation with auscultation, chest radiography, and computed tomography.

PubMed

Tasci, Ozlem; Hatipoglu, Osman Nuri; Cagli, Bekir; Ermis, Veli

2016-07-08

The primary purpose of our study was to compare the efficacies of two sonographic (US) probes, a high-frequency linear-array probe and a lower-frequency phased-array sector probe in the diagnosis of basic thoracic pathologies. The secondary purpose was to compare the diagnostic performance of thoracic US with auscultation and chest radiography (CXR) using thoracic CT as a gold standard. In total, 55 consecutive patients scheduled for thoracic CT were enrolled in this prospective study. Four pathologic entities were evaluated: pneumothorax, pleural effusion, consolidation, and interstitial syndrome. A portable US scanner was used with a 5-10-MHz linear-array probe and a 1-5-MHz phased-array sector probe. The first probe used was chosen randomly. US, CXR, and auscultation results were compared with the CT results. The linear-array probe had the highest performance in the identification of pneumothorax (83% sensitivity, 100% specificity, and 99% diagnostic accuracy) and pleural effusion (100% sensitivity, 97% specificity, and 98% diagnostic accuracy); the sector probe had the highest performance in the identification of consolidation (89% sensitivity, 100% specificity, and 95% diagnostic accuracy) and interstitial syndrome (94% sensitivity, 93% specificity, and 94% diagnostic accuracy). For all pathologies, the performance of US was superior to those of CXR and auscultation. The linear probe is superior to the sector probe for identifying pleural pathologies, whereas the sector probe is superior to the linear probe for identifying parenchymal pathologies. Thoracic US has better diagnostic performance than CXR and auscultation for the diagnosis of common pathologic conditions of the chest. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:383-389, 2016. © 2016 Wiley Periodicals, Inc.

Malaria Diagnostics in Clinical Trials

PubMed Central

Murphy, Sean C.; Shott, Joseph P.; Parikh, Sunil; Etter, Paige; Prescott, William R.; Stewart, V. Ann

2013-01-01

Malaria diagnostics are widely used in epidemiologic studies to investigate natural history of disease and in drug and vaccine clinical trials to exclude participants or evaluate efficacy. The Malaria Laboratory Network (MLN), managed by the Office of HIV/AIDS Network Coordination, is an international working group with mutual interests in malaria disease and diagnosis and in human immunodeficiency virus/acquired immunodeficiency syndrome clinical trials. The MLN considered and studied the wide array of available malaria diagnostic tests for their suitability for screening trial participants and/or obtaining study endpoints for malaria clinical trials, including studies of HIV/malaria co-infection and other malaria natural history studies. The MLN provides recommendations on microscopy, rapid diagnostic tests, serologic tests, and molecular assays to guide selection of the most appropriate test(s) for specific research objectives. In addition, this report provides recommendations regarding quality management to ensure reproducibility across sites in clinical trials. Performance evaluation, quality control, and external quality assessment are critical processes that must be implemented in all clinical trials using malaria tests. PMID:24062484

Clinical study of quantitative diagnosis of early cervical cancer based on the classification of acetowhitening kinetics

NASA Astrophysics Data System (ADS)

Wu, Tao; Cheung, Tak-Hong; Yim, So-Fan; Qu, Jianan Y.

2010-03-01

A quantitative colposcopic imaging system for the diagnosis of early cervical cancer is evaluated in a clinical study. This imaging technology based on 3-D active stereo vision and motion tracking extracts diagnostic information from the kinetics of acetowhitening process measured from the cervix of human subjects in vivo. Acetowhitening kinetics measured from 137 cervical sites of 57 subjects are analyzed and classified using multivariate statistical algorithms. Cross-validation methods are used to evaluate the performance of the diagnostic algorithms. The results show that an algorithm for screening precancer produced 95% sensitivity (SE) and 96% specificity (SP) for discriminating normal and human papillomavirus (HPV)-infected tissues from cervical intraepithelial neoplasia (CIN) lesions. For a diagnostic algorithm, 91% SE and 90% SP are achieved for discriminating normal tissue, HPV infected tissue, and low-grade CIN lesions from high-grade CIN lesions. The results demonstrate that the quantitative colposcopic imaging system could provide objective screening and diagnostic information for early detection of cervical cancer.

The development, evaluation and performance of molecular diagnostics for detection of Mycobacterium tuberculosis.

PubMed

Bates, Matthew; Zumla, Alimuddin

2016-01-01

The unique pathogenesis of tuberculosis (TB) poses several barriers to the development of accurate diagnostics: a) the establishment of life-long latency by Mycobacterium tuberculosis (M.tb) after primary infection confounds the development of classical antibody or antigen based assays; b) our poor understanding of the molecular pathways that influence progression from latent to active disease; c) the intracellular nature of M.tb infection in tissues means that M.tb and/or its components, are not readily detectable in peripheral specimens; and d) the variable presence of M.tb bacilli in specimens from patients with extrapulmonary TB or children. The literature on the current portfolio of molecular diagnostics tests for TB is reviewed here and the developmental pipeline is summarized. Also reviewed are data from recently published operational research on the GeneXpert MTB/RIF assay and discussed are the lessons that can be taken forward for the design of studies to evaluate the impact of TB diagnostics.

Estimation of diagnostic test accuracy without full verification: a review of latent class methods

PubMed Central

Collins, John; Huynh, Minh

2014-01-01

The performance of a diagnostic test is best evaluated against a reference test that is without error. For many diseases, this is not possible, and an imperfect reference test must be used. However, diagnostic accuracy estimates may be biased if inaccurately verified status is used as the truth. Statistical models have been developed to handle this situation by treating disease as a latent variable. In this paper, we conduct a systematized review of statistical methods using latent class models for estimating test accuracy and disease prevalence in the absence of complete verification. PMID:24910172

Blister pouches for effective reagent storage and release for low cost point-of-care diagnostic applications

NASA Astrophysics Data System (ADS)

Smith, Suzanne; Sewart, Rene; Land, Kevin; Roux, Pieter; Gärtner, Claudia; Becker, Holger

2016-03-01

Lab-on-a-chip devices are often applied to point-of-care diagnostic solutions as they are low-cost, compact, disposable, and require only small sample volumes. For such devices, various reagents are required for sample preparation and analysis and, for an integrated solution to be realized, on-chip reagent storage and automated introduction are required. This work describes the implementation and characterization of effective liquid reagent storage and release mechanisms utilizing blister pouches applied to various point-of-care diagnostic device applications. The manufacturing aspects as well as performance parameters are evaluated.

Diagnostic Accuracy of Abdominal Ultrasound for Diagnosis of Acute Appendicitis: Systematic Review and Meta-analysis.

PubMed

Giljaca, Vanja; Nadarevic, Tin; Poropat, Goran; Nadarevic, Vesna Stefanac; Stimac, Davor

2017-03-01

To determine the diagnostic accuracy of abdominal ultrasound (US) for the diagnosis of acute appendicitis (AA), in terms of sensitivity, specificity and post-test probabilities for positive and negative result. A systematic search of MEDLINE, Embase, The Cochrane library and Science Citation Index Expanded from January 1994 to October 2014 was performed. Two authors independently evaluated studies for inclusion, extracted data and performed analyses. The reference standard for evaluation of final diagnosis was pathohistological report on tissue obtained at appendectomy. Summary sensitivity, specificity and post-test probability of AA after positive and negative result of US with corresponding 95% confidence intervals (CI) were calculated. Out of 3306 references identified through electronic searches, 17 reports met the inclusion criteria, with 2841 included participants. The summary sensitivity and specificity of US for diagnosis of AA were 69% (95% CI 59-78%) and 81% (95% CI 73-88%), respectively. At the median pretest probability of AA of 76.4%, the post-test probability for a positive and negative result of US was 92% (95% CI 88-95%) and 55% (95% CI 46-63%), respectively. Abdominal ultrasound does not seem to have a role in the diagnostic pathway for diagnosis of AA in suspected patients. The summary sensitivity and specificity of US do not exceed that of physical examination. Patients that require additional diagnostic workup should be referred to more sensitive and specific diagnostic procedures, such as computed tomography.

Structured syncope care pathways based on lean six sigma methodology optimises resource use with shorter time to diagnosis and increased diagnostic yield.

PubMed

Martens, Leon; Goode, Grahame; Wold, Johan F H; Beck, Lionel; Martin, Georgina; Perings, Christian; Stolt, Pelle; Baggerman, Lucas

2014-01-01

To conduct a pilot study on the potential to optimise care pathways in syncope/Transient Loss of Consciousness management by using Lean Six Sigma methodology while maintaining compliance with ESC and/or NICE guidelines. Five hospitals in four European countries took part. The Lean Six Sigma methodology consisted of 3 phases: 1) Assessment phase, in which baseline performance was mapped in each centre, processes were evaluated and a new operational model was developed with an improvement plan that included best practices and change management; 2) Improvement phase, in which optimisation pathways and standardised best practice tools and forms were developed and implemented. Staff were trained on new processes and change-management support provided; 3) Sustaining phase, which included support, refinement of tools and metrics. The impact of the implementation of new pathways was evaluated on number of tests performed, diagnostic yield, time to diagnosis and compliance with guidelines. One hospital with focus on geriatric populations was analysed separately from the other four. With the new pathways, there was a 59% reduction in the average time to diagnosis (p = 0.048) and a 75% increase in diagnostic yield (p = 0.007). There was a marked reduction in repetitions of diagnostic tests and improved prioritisation of indicated tests. Applying a structured Lean Six Sigma based methodology to pathways for syncope management has the potential to improve time to diagnosis and diagnostic yield.

Structured Syncope Care Pathways Based on Lean Six Sigma Methodology Optimises Resource Use with Shorter Time to Diagnosis and Increased Diagnostic Yield

PubMed Central

Martens, Leon; Goode, Grahame; Wold, Johan F. H.; Beck, Lionel; Martin, Georgina; Perings, Christian; Stolt, Pelle; Baggerman, Lucas

2014-01-01

Aims To conduct a pilot study on the potential to optimise care pathways in syncope/Transient Loss of Consciousness management by using Lean Six Sigma methodology while maintaining compliance with ESC and/or NICE guidelines. Methods Five hospitals in four European countries took part. The Lean Six Sigma methodology consisted of 3 phases: 1) Assessment phase, in which baseline performance was mapped in each centre, processes were evaluated and a new operational model was developed with an improvement plan that included best practices and change management; 2) Improvement phase, in which optimisation pathways and standardised best practice tools and forms were developed and implemented. Staff were trained on new processes and change-management support provided; 3) Sustaining phase, which included support, refinement of tools and metrics. The impact of the implementation of new pathways was evaluated on number of tests performed, diagnostic yield, time to diagnosis and compliance with guidelines. One hospital with focus on geriatric populations was analysed separately from the other four. Results With the new pathways, there was a 59% reduction in the average time to diagnosis (p = 0.048) and a 75% increase in diagnostic yield (p = 0.007). There was a marked reduction in repetitions of diagnostic tests and improved prioritisation of indicated tests. Conclusions Applying a structured Lean Six Sigma based methodology to pathways for syncope management has the potential to improve time to diagnosis and diagnostic yield. PMID:24927475

System Related Interventions to Reduce Diagnostic Error: A Narrative Review

PubMed Central

Singh, Hardeep; Graber, Mark L.; Kissam, Stephanie M.; Sorensen, Asta V.; Lenfestey, Nancy F.; Tant, Elizabeth M.; Henriksen, Kerm; LaBresh, Kenneth A.

2013-01-01

Background Diagnostic errors (missed, delayed, or wrong diagnosis) have gained recent attention and are associated with significant preventable morbidity and mortality. We reviewed the recent literature to identify interventions that have been, or could be, implemented to address systems-related factors that contribute directly to diagnostic error. Methods We conducted a comprehensive search using multiple search strategies. We first identified candidate articles in English between 2000 and 2009 from a PubMed search that exclusively evaluated for articles related to diagnostic error or delay. We then sought additional papers from references in the initial dataset, searches of additional databases, and subject matter experts. Articles were included if they formally evaluated an intervention to prevent or reduce diagnostic error; however, we also included papers if interventions were suggested and not tested in order to inform the state-of-the science on the topic. We categorized interventions according to the step in the diagnostic process they targeted: patient-provider encounter, performance and interpretation of diagnostic tests, follow-up and tracking of diagnostic information, subspecialty and referral-related; and patient-specific. Results We identified 43 articles for full review, of which 6 reported tested interventions and 37 contained suggestions for possible interventions. Empirical studies, though somewhat positive, were non-experimental or quasi-experimental and included a small number of clinicians or health care sites. Outcome measures in general were underdeveloped and varied markedly between studies, depending on the setting or step in the diagnostic process involved. Conclusions Despite a number of suggested interventions in the literature, few empirical studies have tested interventions to reduce diagnostic error in the last decade. Advancing the science of diagnostic error prevention will require more robust study designs and rigorous definitions of diagnostic processes and outcomes to measure intervention effects. PMID:22129930

Diagnostic evaluations of ultrasound and magnetic resonance imaging in mammary duct ectasia and breast cancer

PubMed Central

Song, Lei; Li, Liang; Liu, Bin; Yu, Dexin; Sun, Fengguo; Guo, Mingming; Ruan, Zhengmin; Zhang, Feixue

2018-01-01

The objective of the present study was to evaluate the diagnostic efficiency of ultrasound (US) and magnetic resonance imaging (MRI) in the diagnosis and differential diagnosis of mammary duct ectasia (MDE) and breast cancer. This retrospective study was performed on 35 patients with MDE and 105 patients with breast cancer using US and MRI. Imaging features, semi-quantitative and quantitative parameters were analyzed to determine their diagnostic value for MDE and breast cancer. The average age of patients with breast cancer was increased compared with that of patients with MDE. There were no significant differences in local packages with or without tenderness ratio (P=0.259) and grade of color Doppler flow imaging (P=0.273) between the two groups. However, the morphological changes were significantly increased in breast cancer compared with MDE. In addition, there were significant diagnostic differences in US and MRI between breast cancer and MDE, including resistance index, US elastography, time-signal intensity curve, apparent diffusion coefficient, early-stage enhancement ratio, peak-of-enhancement ratio and Tpeak (P<0.05). However, there were no observable significant diagnostic differences between US, MRI and US with MRI for MDE and breast cancer (P=0.103, P=0.263 and P=0.403 respectively). Diagnosis of MDE and breast cancer requires full evaluation of multiple parameters and morphological changes of US and MRI to increase the diagnostic efficiency. US, MRI and US with MRI were all of diagnostic value for MDE and breast cancer, while US with MRI had the highest efficacy. PMID:29434865

A new computerized diagnostic algorithm for quantitative evaluation of binocular misalignment in patients with strabismus

NASA Astrophysics Data System (ADS)

Nam, Kyoung Won; Kim, In Young; Kang, Ho Chul; Yang, Hee Kyung; Yoon, Chang Ki; Hwang, Jeong Min; Kim, Young Jae; Kim, Tae Yun; Kim, Kwang Gi

2012-10-01

Accurate measurement of binocular misalignment between both eyes is important for proper preoperative management, surgical planning, and postoperative evaluation of patients with strabismus. In this study, we proposed a new computerized diagnostic algorithm that can calculate the angle of binocular eye misalignment photographically by using a dedicated three-dimensional eye model mimicking the structure of the natural human eye. To evaluate the performance of the proposed algorithm, eight healthy volunteers and eight individuals with strabismus were recruited in this study, the horizontal deviation angle, vertical deviation angle, and angle of eye misalignment were calculated and the angular differences between the healthy and the strabismus groups were evaluated using the nonparametric Mann-Whitney test and the Pearson correlation test. The experimental results demonstrated a statistically significant difference between the healthy and strabismus groups (p = 0.015 < 0.05), but no statistically significant difference between the proposed method and the Krimsky test (p = 0.912 > 0.05). The measurements of the two methods were highly correlated (r = 0.969, p < 0.05). From the experimental results, we believe that the proposed diagnostic method has the potential to be a diagnostic tool that measures the physical disorder of the human eye to diagnose non-invasively the severity of strabismus.

Performance characteristics of magnetic resonance imaging without contrast agents or sedation in pediatric appendicitis.

PubMed

Didier, Ryne A; Hopkins, Katharine L; Coakley, Fergus V; Krishnaswami, Sanjay; Spiro, David M; Foster, Bryan R

2017-09-01

Magnetic resonance imaging (MRI) has emerged as a promising modality for evaluating pediatric appendicitis. However optimal imaging protocols, including roles of contrast agents and sedation, have not been established and diagnostic criteria have not been fully evaluated. To investigate performance characteristics of rapid MRI without contrast agents or sedation in the diagnosis of pediatric appendicitis. We included patients ages 4-18 years with suspicion of appendicitis who underwent rapid MRI between October 2013 and March 2015 without contrast agent or sedation. After two-radiologist review, we determined performance characteristics of individual diagnostic criteria and aggregate diagnostic criteria by comparing MRI results to clinical outcomes. We used receiver operating characteristic (ROC) curves to determine cut-points for appendiceal diameter and wall thickness for optimization of predictive power, and we calculated area under the curve (AUC) as a measure of test accuracy. Ninety-eight MRI examinations were performed in 97 subjects. Overall, MRI had a 94% sensitivity, 95% specificity, 91% positive predictive value and 97% negative predictive value. Optimal cut-points for appendiceal diameter and wall thickness were ≥7 mm and ≥2 mm, respectively. Independently, those cut-points produced sensitivities of 91% and 84% and specificities of 84% and 43%. Presence of intraluminal fluid (30/33) or localized periappendiceal fluid (32/33) showed a significant association with acute appendicitis (P<0.01), with sensitivities of 91% and 97% and specificities of 60% and 50%. For examinations in which the appendix was not identified by one or both reviewers (23/98), the clinical outcome was negative. Rapid MRI without contrast agents or sedation is accurate for diagnosis of pediatric appendicitis when multiple diagnostic criteria are considered in aggregate. Individual diagnostic criteria including optimized cut-points of ≥7 mm for diameter and ≥2 mm for wall thickness demonstrate high sensitivities but relatively low specificities. Nonvisualization of the appendix favors a negative diagnosis.

Management of uncomplicated malaria in febrile under five-year-old children by community health workers in Madagascar: reliability of malaria rapid diagnostic tests

PubMed Central

2012-01-01

Background Early diagnosis, as well as prompt and effective treatment of uncomplicated malaria, are essential components of the anti-malaria strategy in Madagascar to prevent severe malaria, reduce mortality and limit malaria transmission. The purpose of this study was to assess the performance of the malaria rapid diagnostic tests (RDTs) used by community health workers (CHWs) by comparing RDT results with two reference methods (microscopy and Polymerase Chain Reaction, PCR). Methods Eight CHWs in two districts, each with a different level of endemic malaria transmission, were trained to use RDTs in the management of febrile children under five years of age. RDTs were performed by CHWs in all febrile children who consulted for fever. In parallel, retrospective parasitological diagnoses were made by microscopy and PCR. The results of these different diagnostic methods were analysed to evaluate the diagnostic performance of the RDTs administered by the CHWs. The stability of the RDTs stored by CHWs was also evaluated. Results Among 190 febrile children with suspected malaria who visited CHWs between February 2009 and February 2010, 89.5% were found to be positive for malaria parasites by PCR, 51.6% were positive by microscopy and 55.8% were positive by RDT. The performance accuracy of the RDTs used by CHWs in terms of sensitivity, specificity, positive and negative predictive values was greater than 85%. Concordance between microscopy and RDT, estimated by the Kappa value was 0.83 (95% CI: 0.75-0.91). RDTs stored by CHWs for 24 months were capable of detecting Plasmodium falciparum in blood at a level of 200 parasites/μl. Conclusion Introduction of easy-to-use diagnostic tools, such as RDTs, at the community level appears to be an effective strategy for improving febrile patient management and for reducing excessive use of anti-malarial drugs. PMID:22443344

Management of uncomplicated malaria in febrile under five-year-old children by community health workers in Madagascar: reliability of malaria rapid diagnostic tests.

PubMed

Ratsimbasoa, Arsène; Ravony, Harintsoa; Vonimpaisomihanta, Jeanne-Aimée; Raherinjafy, Rogelin; Jahevitra, Martial; Rapelanoro, Rabenja; Rakotomanga, Jean De Dieu Marie; Malvy, Denis; Millet, Pascal; Ménard, Didier

2012-03-25

Early diagnosis, as well as prompt and effective treatment of uncomplicated malaria, are essential components of the anti-malaria strategy in Madagascar to prevent severe malaria, reduce mortality and limit malaria transmission. The purpose of this study was to assess the performance of the malaria rapid diagnostic tests (RDTs) used by community health workers (CHWs) by comparing RDT results with two reference methods (microscopy and Polymerase Chain Reaction, PCR). Eight CHWs in two districts, each with a different level of endemic malaria transmission, were trained to use RDTs in the management of febrile children under five years of age. RDTs were performed by CHWs in all febrile children who consulted for fever. In parallel, retrospective parasitological diagnoses were made by microscopy and PCR. The results of these different diagnostic methods were analysed to evaluate the diagnostic performance of the RDTs administered by the CHWs. The stability of the RDTs stored by CHWs was also evaluated. Among 190 febrile children with suspected malaria who visited CHWs between February 2009 and February 2010, 89.5% were found to be positive for malaria parasites by PCR, 51.6% were positive by microscopy and 55.8% were positive by RDT. The performance accuracy of the RDTs used by CHWs in terms of sensitivity, specificity, positive and negative predictive values was greater than 85%. Concordance between microscopy and RDT, estimated by the Kappa value was 0.83 (95% CI: 0.75-0.91). RDTs stored by CHWs for 24 months were capable of detecting Plasmodium falciparum in blood at a level of 200 parasites/μl. Introduction of easy-to-use diagnostic tools, such as RDTs, at the community level appears to be an effective strategy for improving febrile patient management and for reducing excessive use of anti-malarial drugs.

Optical systems for point-of-care diagnostic instrumentation: analysis of imaging performance and cost.

PubMed

Pierce, Mark C; Weigum, Shannon E; Jaslove, Jacob M; Richards-Kortum, Rebecca; Tkaczyk, Tomasz S

2014-01-01

One of the key elements in point-of-care (POC) diagnostic test instrumentation is the optical system required for signal detection and/or imaging. Many tests which use fluorescence, absorbance, or colorimetric optical signals are under development for management of infectious diseases in resource limited settings, where the overall size and cost of the device is of critical importance. At present, high-performance lenses are expensive to fabricate and difficult to obtain commercially, presenting barriers for developers of in vitro POC tests or microscopic image-based diagnostics. We recently described a compact "hybrid" objective lens incorporating both glass and plastic optical elements, with a numerical aperture of 1.0 and field-of-view of 250 μm. This design concept may potentially enable mass-production of high-performance, low-cost optical systems which can be easily incorporated in the readout path of existing and emerging POC diagnostic assays. In this paper, we evaluate the biological imaging performance of these lens systems in three broad POC diagnostic application areas; (1) bright field microscopy of histopathology slides, (2) cytologic examination of blood smears, and (3) immunofluorescence imaging. We also break down the fabrication costs and draw comparisons with other miniature optical systems. The hybrid lenses provided images with quality comparable to conventional microscopy, enabling examination of neoplastic pathology and infectious parasites including malaria and cryptosporidium. We describe how these components can be produced at below $10 per unit in full-scale production quantities, making these systems well suited for use within POC diagnostic instrumentation.

Thoracoabdominal Computed Tomography in Trauma Patients: A Cost-Consequences Analysis

PubMed Central

van Vugt, Raoul; Kool, Digna R.; Brink, Monique; Dekker, Helena M.; Deunk, Jaap; Edwards, Michael J.

2014-01-01

Background: CT is increasingly used during the initial evaluation of blunt trauma patients. In this era of increasing cost-awareness, the pros and cons of CT have to be assessed. Objectives: This study was performed to evaluate cost-consequences of different diagnostic algorithms that use thoracoabdominal CT in primary evaluation of adult patients with high-energy blunt trauma. Materials and Methods: We compared three different algorithms in which CT was applied as an immediate diagnostic tool (rush CT), a diagnostic tool after limited conventional work-up (routine CT), and a selective tool (selective CT). Probabilities of detecting and missing clinically relevant injuries were retrospectively derived. We collected data on radiation exposure and performed a micro-cost analysis on a reference case-based approach. Results: Both rush and routine CT detected all thoracoabdominal injuries in 99.1% of the patients during primary evaluation (n = 1040). Selective CT missed one or more diagnoses in 11% of the patients in which a change of treatment was necessary in 4.8%. Rush CT algorithm costed € 2676 (US$ 3660) per patient with a mean radiation dose of 26.40 mSv per patient. Routine CT costed € 2815 (US$ 3850) and resulted in the same radiation exposure. Selective CT resulted in less radiation dose (23.23 mSv) and costed € 2771 (US$ 3790). Conclusions: Rush CT seems to result in the least costs and is comparable in terms of radiation dose exposure and diagnostic certainty with routine CT after a limited conventional work-up. However, selective CT results in less radiation dose exposure but a slightly higher cost and less certainty. PMID:25337521

Office hysteroscopic-guided selective tubal chromopertubation: acceptability, feasibility and diagnostic accuracy of this new diagnostic non-invasive technique in infertile women.

PubMed

Carta, Gaspare; Palermo, Patrizia; Pasquale, Chiara; Conte, Valeria; Pulcinella, Ruggero; Necozione, Stefano; Cofini, Vincenza; Patacchiola, Felice

2018-06-01

The aim of this study was to evaluate accuracy, tolerability and side effects of office hysteroscopic-guided chromoperturbations in infertile women without anaesthesia. Forty-nine infertile women underwent the procedure to evaluate tubal patency and the uterine cavity. Women with unilateral or bilateral tubal stenosis at hysteroscopy with chromoperturbation, and women with bilateral tubal patency who did not conceive during the period of six months, underwent laparoscopy with chromoperturbation. The results obtained from hysteroscopy and laparoscopy in the assessment of tubal patency were compared. Sensitivity, specificity, accuracy, positive-predictive value and negative-predictive value were used to describe diagnostic performance. Pain and tolerance were assessed during procedure using a visual analogue scale (VAS). Side effects or late complications and pregnancy rate were also recorded three and six months after the procedure. The specificity was 87.8% (95% CI: 73.80-95.90), sensitivity was 85.7% (95% CI 57.20-98.20), positive and negative predictive values were 70.6% (95% CI: 44.00-89) and 94.7% (95% CI: 82.30-99.40), respectively. Pregnancy rate (PR) within six months after performance of hysteroscopy with chromoperturbation was 27%. Office hysteroscopy-guided selective chromoperturbation in infertile patients is a valid technique to evaluate tubal patency and uterine cavity.

Power calculation for comparing diagnostic accuracies in a multi-reader, multi-test design.

PubMed

Kim, Eunhee; Zhang, Zheng; Wang, Youdan; Zeng, Donglin

2014-12-01

Receiver operating characteristic (ROC) analysis is widely used to evaluate the performance of diagnostic tests with continuous or ordinal responses. A popular study design for assessing the accuracy of diagnostic tests involves multiple readers interpreting multiple diagnostic test results, called the multi-reader, multi-test design. Although several different approaches to analyzing data from this design exist, few methods have discussed the sample size and power issues. In this article, we develop a power formula to compare the correlated areas under the ROC curves (AUC) in a multi-reader, multi-test design. We present a nonparametric approach to estimate and compare the correlated AUCs by extending DeLong et al.'s (1988, Biometrics 44, 837-845) approach. A power formula is derived based on the asymptotic distribution of the nonparametric AUCs. Simulation studies are conducted to demonstrate the performance of the proposed power formula and an example is provided to illustrate the proposed procedure. © 2014, The International Biometric Society.

Analysis of "dry" mesothelioma with ultrasound guided biopsies.

PubMed

Stigt, Jos A; Boers, James E; Groen, Harry J M

2012-12-01

Image-guided sampling of the thickened pleura is a sensitive approach in patients with malignant pleural mesothelioma with pleural effusion. Malignant pleural mesothelioma presenting without effusion however is more of a diagnostic challenge. In this study we report the diagnostic yield and complications of ultrasound-guided cutting needle biopsies in this particular category of patients. A retrospective database analysis from September 2007 until January 2012 was performed in 56 patients with malignant pleural mesothelioma. Clinical characteristics and results of diagnostic evaluations were analysed. Of the 56 patients with malignant pleural mesothelioma, 20 patients presented without pleural effusion of with locular effusion. Ultrasound-guided cutting needle biopsy was performed in 14/20 patients with a diagnostic accuracy of 80%. Only 1 patient had mild haemoptysis immediately following biopsies. Diagnosing patients with pleural thickenings suspect for malignant mesothelioma without pleural effusion or with loculated pleural effusion is effective and safe with ultrasound-guided cutting needle biopsies. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Performance and life evaluation of advanced battery technologies for electric vehicle applications

NASA Astrophysics Data System (ADS)

Deluca, W. H.; Gillie, K. R.; Kulaga, J. E.; Smaga, J. A.; Tummillo, A. F.; Webster, C. E.

Advanced battery technology evaluations are performed under simulated electric vehicle (EV) operating conditions at the Argonne Analysis and Diagnostic Laboratory (ADL). The ADL provides a common basis for both performance characterization and life evaluation with unbiased application of tests and analyses. This paper summarizes the performance characterizations and life evaluations conducted in 1990 on nine single cells and fifteen 3- to 360-cell modules that encompass six technologies: (Na/S, Zn/Br, Ni/Fe, Ni/Cd, Ni-metal hydride, and lead-acid). These evaluations were performed for the Department of Energy and Electric Power Research Institute. The results provide battery users, developers, and program managers an interim measure of the progress being made in battery R and D programs, a comparison of battery technologies, and a source of basic data for modelling and continuing R and D.

Reproducibility and diagnostic performance of shear wave elastography in evaluating breast solid mass.

PubMed

Hong, Sun; Woo, Ok Hee; Shin, Hye Seon; Hwang, Soon-Young; Cho, Kyu Ran; Seo, Bo Kyoung

Shear wave elastography (SWE) was performed independently by two radiologists in 264 solid breast masses. The images were reviewed for color overlay pattern (COP) classification by the two radiologists, double blinded to any information. The interobserver agreement of the COP was almost perfect (κ=0.908) and high in E max (ICC=0.89). The AUC value of the COP (0.954) was significantly higher than that of E max (0.915) (p=0.002) but not significantly different from that of E max combined with COP (0.957) (p=0.098). The SWE color overlay pattern and E max of breast masses were highly reproducible. The COP had better diagnostic ability than E max , suggesting that COP may be a more reliable parameter for solid breast mass evaluation. Copyright © 2017 Elsevier Inc. All rights reserved.

Key results of battery performance and life tests at Argonne National Laboratory

NASA Astrophysics Data System (ADS)

Deluca, W. H.; Gillie, K. R.; Kulaga, J. E.; Smaga, J. A.; Tummillo, A. F.; Webster, C. E.

1991-12-01

Advanced battery technology evaluations are performed under simulated electric vehicle operating conditions at Argonne National Laboratory's & Diagnostic Laboratory (ADL). The ADL provide a common basis for both performance characterization and life evaluation with unbiased application of tests and analyses. This paper summarizes the performance characterizations and life evaluations conducted in 1991 on twelve single cells and eight 3- to 360-cell modules that encompass six battery technologies (Na/S, Li/MS, Ni/MH, Zn/Br, Ni/Fe, and Pb-Acid). These evaluations were performed for the Department of Energy, Office of Transportation Technologies, Electric and Hybrid Propulsion Division. The results measure progress in battery R & D programs, compare battery technologies, and provide basic data for modeling and continuing R & D to battery users, developers, and program managers.

Integrative analysis of multi-omics data for identifying multi-markers for diagnosing pancreatic cancer

PubMed Central

2015-01-01

Background microRNA (miRNA) expression plays an influential role in cancer classification and malignancy, and miRNAs are feasible as alternative diagnostic markers for pancreatic cancer, a highly aggressive neoplasm with silent early symptoms, high metastatic potential, and resistance to conventional therapies. Methods In this study, we evaluated the benefits of multi-omics data analysis by integrating miRNA and mRNA expression data in pancreatic cancer. Using support vector machine (SVM) modelling and leave-one-out cross validation (LOOCV), we evaluated the diagnostic performance of single- or multi-markers based on miRNA and mRNA expression profiles from 104 PDAC tissues and 17 benign pancreatic tissues. For selecting even more reliable and robust markers, we performed validation by independent datasets from the Gene Expression Omnibus (GEO) and the Cancer Genome Atlas (TCGA) data depositories. For validation, miRNA activity was estimated by miRNA-target gene interaction and mRNA expression datasets in pancreatic cancer. Results Using a comprehensive identification approach, we successfully identified 705 multi-markers having powerful diagnostic performance for PDAC. In addition, these marker candidates annotated with cancer pathways using gene ontology analysis. Conclusions Our prediction models have strong potential for the diagnosis of pancreatic cancer. PMID:26328610

Evaluation of Orthopedic Metal Artifact Reduction Application in Three-Dimensional Computed Tomography Reconstruction of Spinal Instrumentation: A Single Saudi Center Experience.

PubMed

Ali, Amir Monir

2018-01-01

The aim of the study was to evaluate the commercially available orthopedic metal artifact reduction (OMAR) technique in postoperative three-dimensional computed tomography (3DCT) reconstruction studies after spinal instrumentation and to investigate its clinical application. One hundred and twenty (120) patients with spinal metallic implants were included in the study. All had 3DCT reconstruction examinations using the OMAR software after obtaining the informed consents and approval of the Institution Ethical Committee. The degree of the artifacts, the related muscular density, the clearness of intermuscular fat planes, and definition of the adjacent vertebrae were qualitatively evaluated. The diagnostic satisfaction and quality of the 3D reconstruction images were thoroughly assessed. The majority (96.7%) of 3DCT reconstruction images performed were considered satisfactory to excellent for diagnosis. Only 3.3% of the reconstructed images had rendered unacceptable diagnostic quality. OMAR can effectively reduce metallic artifacts in patients with spinal instrumentation with highly diagnostic 3DCT reconstruction images.

The AcCell series 2000 as a support system for training and evaluation in educational and clinical settings.

PubMed

Greening, S E; Grohs, D H; Guidos, B J

1997-01-01

Providing effective training, retraining and evaluation programs, including proficiency testing programs, for cytoprofessionals is a challenge shared by many academic and clinical educators internationally. In cytopathology the quality of training has immediately transferable and critically important impacts on satisfactory performance in the clinical setting. Well-designed interactive computer-assisted instruction and testing programs have been shown to enhance initial learning and to reinforce factual and conceptual knowledge. Computer systems designed not only to promote diagnostic accuracy but to integrate and streamline work flow in clinical service settings are candidates for educational adaptation. The AcCell 2000 system, designed as a diagnostic screening support system, offers technology that is adaptable to educational needs during basic and in-service training as well as testing of screening proficiency in both locator and identification skills. We describe the considerations, approaches and applications of the AcCell 2000 system in education programs for both training and evaluation of gynecologic diagnostic screening proficiency.

Radiation levels and image quality in patients undergoing chest X-ray examinations

NASA Astrophysics Data System (ADS)

de Oliveira, Paulo Márcio Campos; do Carmo Santana, Priscila; de Sousa Lacerda, Marco Aurélio; da Silva, Teógenes Augusto

2017-11-01

Patient dose monitoring for different radiographic procedures has been used as a parameter to evaluate the performance of radiology services; skin entrance absorbed dose values for each type of examination were internationally established and recommended aiming patient protection. In this work, a methodology for dose evaluation was applied to three diagnostic services: one with a conventional film and two with digital computerized radiography processing techniques. The x-ray beam parameters were selected and "doses" (specifically the entrance surface and incident air kerma) were evaluated based on images approved in European criteria during postero-anterior (PA) and lateral (LAT) incidences. Data were collected from 200 patients related to 200 PA and 100 LAT incidences. Results showed that doses distributions in the three diagnostic services were very different; the best relation between dose and image quality was found in the institution with the chemical film processing. This work contributed for disseminating the radiation protection culture by emphasizing the need of a continuous dose reduction without losing the quality of the diagnostic image.

Use of the Filovirus Animal Non-Clinical Group (FANG) Ebola virus immuno-assay requires fewer study participants to power a study than the Alpha Diagnostic International assay

PubMed Central

Logue, James; Tuznik, Kaylie; Follmann, Dean; Grandits, Greg; Marchand, Jonathan; Reilly, Cavan; Sarro, Yeya dit Sadio; Pettitt, James; Stavale, Eric J.; Fallah, Mosoka; Olinger, Gene G.; Bolay, Fatorma K.; Hensley, Lisa E.

2018-01-01

As part of the scientific community’s development of medical countermeasures against Ebola virus disease, optimization of standardized assays for product evaluation is paramount. The recent outbreak heightened awareness to the scarcity of available assays and limited information on performance and reproducibility. To evaluate the immunogenicity of vaccines entering Phase I–III trials and to identify survivors, two enzyme-linked immunosorbent assays, the Filovirus Animal Non-Clinical Group assay and the Alpha Diagnostics International assay, were evaluated for detection of immunoglobulin G against Ebola virus glycoprotein. We found that the Filovirus Animal Nonclinical Group assay produced a wider range of relative antibody concentrations, higher assay precision, larger relative accuracy range, and lower regional background. Additionally, to sufficiently power a vaccine trial, use of the Filovirus Animal Nonclinical Group assay would require one third the number of participants than the Alpha Diagnostics International assay. This reduction in needed study participants will require less money, fewer man hours, and much less time to evaluate vaccine immunogenicity. PMID:29481881

Diagnostic performance of coronary computed tomography angiography versus exercise electrocardiography for coronary artery disease: a systematic review and meta-analysis.

PubMed

Yin, Xinxin; Wang, Jiali; Zheng, Wen; Ma, Jingjing; Hao, Panpan; Chen, Yuguo

2016-07-01

Both coronary computed tomography angiography (CCTA) and exercise electrocardiography (ExECG) are non-invasive testing methods for the evaluation of coronary artery disease (CAD). However, there was controversy on the diagnostic performance of these methods due to the limited data in each single study. Therefore, we performed a meta-analysis to address these issues. We searched PubMed and Embase databases up to May 22, 2015. Two authors identified eligible studies, extracted data and accessed quality. Pooled estimation of sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), summary receiver-operating characteristic curve (SROC) and the area under curve (AUC) of CCTA and ExECG for the diagnosis of CAD were calculated using Stata, Meta-Disc and Review Manager statistical software. Seven articles were included. Pooled sensitivity of CCTA and ExECG were 0.98 [95% confidence intervals (CIs): 0.95-0.99] and 0.66 (95% CIs: 0.59-0.72); pooled specificity of CCTA and ExECG were 0.84 (95% CIs: 0.81-0.87) and 0.75 (95% CIs: 0.71-0.79); pooled DOR of CCTA and ExECG were 110.24 (95% CIs: 35.07-346.55) and 6.28 (95% CIs: 2.06-19.13); and AUC of CCTA and ExECG were 0.9950±0.0046 and 0.7727±0.0638, respectively. There is no heterogeneity caused by threshold effect in CCTA or ExECG analysis. The Deeks' test showed no potential publication bias (P=0.17). CCTA has better diagnostic performance than ExECG in the evaluation of CAD, which can provide a better solution for the clinical problem of the diagnosis for CAD.

Diagnostic accuracy of an iPhone DICOM viewer for the interpretation of magnetic resonance imaging of the knee.

PubMed

De Maio, Peter; White, Lawrence M; Bleakney, Robert; Menezes, Ravi J; Theodoropoulos, John

2014-07-01

To evaluate the diagnostic performance of viewing magnetic resonance (MR) images on a handheld mobile device compared with a conventional radiology workstation for the diagnosis of intra-articular knee pathology. Prospective comparison study. Tertiary care center. Fifty consecutive subjects who had MR imaging of the knee followed by knee arthroscopy were prospectively evaluated. Two musculoskeletal radiologists independently reviewed each MR study using 2 different viewers: the OsiriX DICOM viewer software on an Apple iPhone 3GS device and eFilm Workstation software on a conventional picture archiving and communications system workstation. Sensitivity and specificity of the iPhone and workstation interpretations was performed using knee arthroscopy as the reference standard. Intraobserver concordance and agreement between the iPhone and workstation interpretations were determined. There was no statistically significant difference between the 2 devices for each paired comparison of diagnostic performance. For the iPhone interpretations, sensitivity ranged from 77% (13 of 17) for the lateral meniscus to 100% (17 of 17) for the anterior cruciate ligament. Specificity ranged from 74% (14 of 19) for cartilage to 100% (50 of 50) for the posterior cruciate ligament. There was a very high level of interobserver and intraobserver agreement between devices and readers. The iPhone reads took longer than the corresponding workstation reads, with a significant mean difference between the iPhone and workstation reads of 3.98 minutes (P < 0.001). The diagnostic performance of interpreting MR images on a handheld mobile device for the assessment of intra-articular knee pathology is similar to that of a conventional radiology workstation, however, requires a longer viewing time. Timely and accurate interpretation of complex medical images using mobile device solutions could result in new workflow efficiencies and ultimately improve patient care.

Contrast-enhanced spectral mammography vs. mammography and MRI - clinical performance in a multi-reader evaluation.

PubMed

Fallenberg, Eva M; Schmitzberger, Florian F; Amer, Heba; Ingold-Heppner, Barbara; Balleyguier, Corinne; Diekmann, Felix; Engelken, Florian; Mann, Ritse M; Renz, Diane M; Bick, Ulrich; Hamm, Bernd; Dromain, Clarisse

2017-07-01

To compare the diagnostic performance of contrast-enhanced spectral mammography (CESM) to digital mammography (MG) and magnetic resonance imaging (MRI) in a prospective two-centre, multi-reader study. One hundred seventy-eight women (mean age 53 years) with invasive breast cancer and/or DCIS were included after ethics board approval. MG, CESM and CESM + MG were evaluated by three blinded radiologists based on amended ACR BI-RADS criteria. MRI was assessed by another group of three readers. Receiver-operating characteristic (ROC) curves were compared. Size measurements for the 70 lesions detected by all readers in each modality were correlated with pathology. Reading results for 604 lesions were available (273 malignant, 4 high-risk, 327 benign). The area under the ROC curve was significantly larger for CESM alone (0.84) and CESM + MG (0.83) compared to MG (0.76) (largest advantage in dense breasts) while it was not significantly different from MRI (0.85). Pearson correlation coefficients for size comparison were 0.61 for MG, 0.69 for CESM, 0.70 for CESM + MG and 0.79 for MRI. This study showed that CESM, alone and in combination with MG, is as accurate as MRI but is superior to MG for lesion detection. Patients with dense breasts benefitted most from CESM with the smallest additional dose compared to MG. • CESM has comparable diagnostic performance (ROC-AUC) to MRI for breast cancer diagnostics. • CESM in combination with MG does not improve diagnostic performance. • CESM has lower sensitivity but higher specificity than MRI. • Sensitivity differences are more pronounced in dense and not significant in non-dense breasts. • CESM and MRI are significantly superior to MG, particularly in dense breasts.

Combining information from 3 anatomic regions in the diagnosis of glaucoma with time-domain optical coherence tomography.

PubMed

Wang, Mingwu; Lu, Ake Tzu-Hui; Varma, Rohit; Schuman, Joel S; Greenfield, David S; Huang, David

2014-03-01

To improve the diagnosis of glaucoma by combining time-domain optical coherence tomography (TD-OCT) measurements of the optic disc, circumpapillary retinal nerve fiber layer (RNFL), and macular retinal thickness. Ninety-six age-matched normal and 96 perimetric glaucoma participants were included in this observational, cross-sectional study. Or-logic, support vector machine, relevance vector machine, and linear discrimination function were used to analyze the performances of combined TD-OCT diagnostic variables. The area under the receiver-operating curve (AROC) was used to evaluate the diagnostic accuracy and to compare the diagnostic performance of single and combined anatomic variables. The best RNFL thickness variables were the inferior (AROC=0.900), overall (AROC=0.892), and superior quadrants (AROC=0.850). The best optic disc variables were horizontal integrated rim width (AROC=0.909), vertical integrated rim area (AROC=0.908), and cup/disc vertical ratio (AROC=0.890). All macular retinal thickness variables had AROCs of 0.829 or less. Combining the top 3 RNFL and optic disc variables in optimizing glaucoma diagnosis, support vector machine had the highest AROC, 0.954, followed by or-logic (AROC=0.946), linear discrimination function (AROC=0.946), and relevance vector machine (AROC=0.943). All combination diagnostic variables had significantly larger AROCs than any single diagnostic variable. There are no significant differences among the combination diagnostic indices. With TD-OCT, RNFL and optic disc variables had better diagnostic accuracy than macular retinal variables. Combining top RNFL and optic disc variables significantly improved diagnostic performance. Clinically, or-logic classification was the most practical analytical tool with sufficient accuracy to diagnose early glaucoma.

Diagnostic accuracy of ultrasonography, MRI and MR arthrography in the characterisation of rotator cuff disorders: a systematic review and meta-analysis

PubMed Central

Roy, Jean-Sébastien; Braën, Caroline; Leblond, Jean; Desmeules, François; Dionne, Clermont E; MacDermid, Joy C; Bureau, Nathalie J; Frémont, Pierre

2015-01-01

Background Different diagnostic imaging modalities, such as ultrasonography (US), MRI, MR arthrography (MRA) are commonly used for the characterisation of rotator cuff (RC) disorders. Since the most recent systematic reviews on medical imaging, multiple diagnostic studies have been published, most using more advanced technological characteristics. The first objective was to perform a meta-analysis on the diagnostic accuracy of medical imaging for characterisation of RC disorders. Since US is used at the point of care in environments such as sports medicine, a secondary analysis assessed accuracy by radiologists and non-radiologists. Methods A systematic search in three databases was conducted. Two raters performed data extraction and evaluation of risk of bias independently, and agreement was achieved by consensus. Hierarchical summary receiver-operating characteristic package was used to calculate pooled estimates of included diagnostic studies. Results Diagnostic accuracy of US, MRI and MRA in the characterisation of full-thickness RC tears was high with overall estimates of sensitivity and specificity over 0.90. As for partial RC tears and tendinopathy, overall estimates of specificity were also high (>0.90), while sensitivity was lower (0.67–0.83). Diagnostic accuracy of US was similar whether a trained radiologist, sonographer or orthopaedist performed it. Conclusions Our results show the diagnostic accuracy of US, MRI and MRA in the characterisation of full-thickness RC tears. Since full thickness tear constitutes a key consideration for surgical repair, this is an important characteristic when selecting an imaging modality for RC disorder. When considering accuracy, cost, and safety, US is the best option. PMID:25677796

Two- and three-dimensional transvaginal ultrasound with power Doppler angiography and gel infusion sonography for diagnosis of endometrial malignancy.

PubMed

Dueholm, M; Christensen, J W; Rydbjerg, S; Hansen, E S; Ørtoft, G

2015-06-01

To evaluate the diagnostic efficiency of two-dimensional (2D) and three-dimensional (3D) transvaginal ultrasonography, power Doppler angiography (PDA) and gel infusion sonography (GIS) at offline analysis for recognition of malignant endometrium compared with real-time evaluation during scanning, and to determine optimal image parameters at 3D analysis. One hundred and sixty-nine consecutive women with postmenopausal bleeding and endometrial thickness ≥ 5 mm underwent systematic evaluation of endometrial pattern on 2D imaging, and 2D videoclips and 3D volumes were later analyzed offline. Histopathological findings at hysteroscopy or hysterectomy were used as the reference standard. The efficiency of the different techniques for diagnosis of malignancy was calculated and compared. 3D image parameters, endometrial volume and 3D vascular indices were assessed. Optimal 3D image parameters were transformed by logistic regression into a risk of endometrial cancer (REC) score, including scores for body mass index, endometrial thickness and endometrial morphology at gray-scale and PDA and GIS. Offline 2D and 3D analysis were equivalent, but had lower diagnostic performance compared with real-time evaluation during scanning. Their diagnostic performance was not markedly improved by the addition of PDA or GIS, but their efficiency was comparable with that of real-time 2D-GIS in offline examinations of good image quality. On logistic regression, the 3D parameters from the REC-score system had the highest diagnostic efficiency. The area under the curve of the REC-score system at 3D-GIS (0.89) was not improved by inclusion of vascular indices or endometrial volume calculations. Real-time evaluation during scanning is most efficient, but offline 2D and 3D analysis is useful for prediction of endometrial cancer when good image quality can be obtained. The diagnostic efficiency at 3D analysis may be improved by use of REC-scoring systems, without the need for calculation of vascular indices or endometrial volume. The optimal imaging modality appears to be real-time 2D-GIS. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

Performance of hepatitis B assays on the Bayer ADVIA Centaur Immunoassay System.

PubMed

van Helden, Josef; Denoyel, Gérard; Karwowska, Sylwia; Reamer, Randy; Schmalz, John; Wright, Ted; Preisel-Simmons, Barbara

2004-01-01

Bayer HealthCare LLC, Diagnostics Division, has developed several new assays on the ADVIA Centaur immunoassay system for the detection of markers of hepatitis B virus infection in human serum and plasma. This panel includes assays for: hepatitis B surface antigen (HBsAg), a confirmatory test method for HBsAg, antibodies to hepatitis B surface antigen (anti-HBs), IgM and IgG antibodies to hepatitis B core antigen (anti-HBc Total) and IgM antibodies to hepatitis B core antigen (anti-HBc IgM). These assays employ magnetic particle separation technology with direct chemiluminescence for optimal assay performance. All of the assays are fully automated, require sample volumes ranging from 15 microl to 100 microl (with the exception of the ADVIA Centaur HBsAg Confirmatory Assay, which requires 2 x 100 microl), and have throughputs of up to 240 tests per hour. The five ADVIA Centaur HBV assays were tested in extensive performance evaluations conducted at two sites in Europe. The performance evaluations, which included samples from HBV-infected individuals, blood donors, hospitalized/clinical patients, and HBV vaccinees (for Anti-HBs evaluation), generated performance data in support of obtaining the Communautés Européennes (CE) mark for European market distribution. The HBV performance evaluations resulted in an overall diagnostic specificity > 99%, i.e. 99.94% for the ADVIA Centaur HBsAg Assay, 100% for the ADVIA Centaur Anti-HBs Assay, 100% for the ADVIA Centaur HBc IgM Assay and 99.94% for the ADVIA Centaur HBc Total Assay. All of the ADVIA Centaur assays showed a very good diagnostic sensitivity on these populations with 100% for the ADVIA Centaur HBsAg Assay, 99.0% for the ADVIA Centaur Anti-HBs Assay, 98.53% for the ADVIA Centaur HBc IgM Assay and 100% for the ADVIA Centaur HBc Total Assay. The ADVIA Centaur HBsAg Confirmatory Test confirmed 100% of the positive HBsAg samples. Testing of interfering substances and potential cross-reacting samples for all ADVIA Centaur HBV assays resulted in no change in interpretation of the results. Assay performance was further evaluated using HBV seroconversion panels with comparable or better results when compared to the comparison assays. The performance evaluation data demonstrate that the ADVIA Centaur HBV assays are specific and sensitive automated immunoassays for detection of antigens and antibodies to hepatitis B virus with performance that is comparable to those of currently marketed assays. Additionally, these assays have the advantage of being available on the ADVIA Centaur immunoassay system, which provides for the flexibility of high throughput and full automation.

Study on validity of a rapid diagnostic test kit versus light microscopy for malaria diagnosis in Ahmedabad city, India.

PubMed

Vyas, S; Puwar, B; Patel, V; Bhatt, G; Kulkarni, S; Fancy, M

2014-05-01

Light microscopy of blood smears for diagnosis of malaria in the field has several limitations, notably delays in diagnosis. This study in Ahmedabad in Gujarat State, India, evaluated the diagnostic performance of a rapid diagnostic test for malaria (SD Bioline Malaria Ag P.f/Pan) versus blood smear examination as the gold standard. All fever cases presenting at 13 urban health centres were subjected to rapid diagnostic testing and thick and thin blood smears. A total of 677 cases with fever were examined; 135 (20.0%) tested positive by rapid diagnostic test and 86 (12.7%) by blood smear. The sensitivity of the rapid diagnostic test for malaria was 98.8%, specificity was 91.5%, positive predictive value 63.0% and negative predictive value 99.8%. For detection of Plasmodium falciparum the sensitivity of rapid diagnostic test was 100% and specificity was 97.3%. The results show the acceptability of the rapid test as an alternative to light microscopy in the field setting.

Diagnostic performance of multi-slice CT angiography combined with enterography for small bowel obstruction and intestinal ischaemia.

PubMed

He, Bosheng; Gu, Jinhua; Huang, Sheng; Gao, Xuesong; Fan, Jinhe; Sheng, Meihong; Wang, Lin; Gong, Shenchu

2017-02-01

This study was performed to evaluate the diagnostic performance of multi-slice CT angiography combined with enterography in determining the cause and location of obstruction as well as intestinal ischaemia in patients with small bowel obstruction (SBO). This study retrospectively summarized the image data of 57 SBO patients who received both multi-slice CT angiography and enterography examination between December 2012 and May 2013. The CT diagnoses of SBO and intestinal ischaemia were correlated with the findings at surgery or digital subtraction angiography, which were set as standard references. Multi-slice CT angiography and enterography indicated that the cause of SBO in three patients was misjudged, suggesting a diagnostic accuracy of 94.7%. In one patient the level of obstruction was incorrect, demonstrating a diagnostic accuracy of 98.2%. Based on the results of the receiver operating characteristic (ROC) curve analysis, the diagnostic criterion for ischaemic SBO was at least two of the four CT signs (circumferential bowel wall thickening, reduced enhancement of the intestinal wall, mesenteric oedema and mesenteric vascular engorgement). The criterion yielded a sensitivity of 94.4%, a specificity of 92.3%, a positive predicted value of 85.0% and a negative predicted value of 97.3%, and the area under curve (AUC) was 0.92 (95% CI, 0.85-0.99). Multi-slice CT angiography and enterography have high diagnostic value in identifying the cause and site of SBO. In addition, the suggested diagnostic criterion using CT signs is helpful for diagnosing intestinal ischaemia in SBO patients. © 2016 The Royal Australian and New Zealand College of Radiologists.

Atypical birefringence pattern and the diagnostic ability of scanning laser polarimetry with enhanced corneal compensation in glaucoma.

PubMed

Rao, Harsha L; Yadav, Ravi K; Begum, Viquar U; Addepalli, Uday K; Senthil, Sirisha; Choudhari, Nikhil S; Garudadri, Chandra S

2015-03-01

To evaluate the effect of typical scan score (TSS), when within the acceptable limits, on the diagnostic performance of retinal nerve fibre layer (RNFL) parameters with the enhanced corneal compensation (ECC) protocol of scanning laser polarimetry (SLP) in glaucoma. In a cross-sectional study, 203 eyes of 160 glaucoma patients and 140 eyes of 104 control subjects underwent RNFL imaging with the ECC protocol of SLP. TSS was used to quantify atypical birefringence pattern (ABP) images. Influence of TSS on the diagnostic ability of SLP parameters was evaluated by receiver operating characteristic (ROC) regression models after adjusting for the effect of disease severity [based on mean deviation (MD)] on standard automated perimetry). Diagnostic abilities of all RNFL parameters of SLP increased when the TSS values were higher. This effect was statistically significant for TSNIT (coefficient: 0.08, p<0.001) and inferior average parameters (coefficient: 0.06, p=0.002) but not for nerve fibre indicator (NFI, coefficient: 0.03, p=0.21). In early glaucoma (MD of -5 dB), predicted area under ROC curve (AUC) for TSNIT average parameter improved from 0.642 at a TSS of 90 to 0.845 at a TSS of 100. In advanced glaucoma (MD of -15 dB), AUC for TSNIT average improved from 0.832 at a TSS of 90 to 0.947 at 100. Diagnostic performances of TSNIT and inferior average RNFL parameters with ECC protocol of SLP were significantly influenced by TSS even when the TSS values were within the acceptable limits. Diagnostic ability of NFI was unaffected by TSS values. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Direct comparison of PI-RADS version 2 and version 1 regarding interreader agreement and diagnostic accuracy for the detection of clinically significant prostate cancer.

PubMed

Becker, Anton S; Cornelius, Alexander; Reiner, Cäcilia S; Stocker, Daniel; Ulbrich, Erika J; Barth, Borna K; Mortezavi, Ashkan; Eberli, Daniel; Donati, Olivio F

2017-09-01

to simultaneously evaluate interreader agreement and diagnostic accuracy in the of PI-RADS v2 and compare it to v1. A total of 67 patients (median age 65.3 y, range 51.2-78.2 y; PSA 6.8μg/L, 0.2-33μg/L) undergoing MRI of the prostate and subsequent transperineal template biopsy within ≤6 months from MRI were included. Four readers from two institutions evaluated the likelihood of prostate cancer using PI-RADS v1 and v2 in two separate reading sessions ≥3 months apart. Interreader agreement was assessed for each pulse-sequence and for total PI-RADS scores using the intraclass correlation coefficient (ICC). Differences were considered significant for non-overlapping 95%-confidence intervals. Diagnostic accuracy was assessed with the area under the receiver operating characteristic curve (A Z ). A p-value <0.05 was considered statistically significant. Interreader agreement for DCE-scores was good in v2 (ICC 2 =0.70; 95% CI: 0.66-0.74) and slightly lower in v1 (ICC 1 =0.64, 0.59-0.69). Agreement for DWI scores (ICC 1 =0.77, ICC 2 =0.76) as well as final PI-RADS scores per quadrant were nearly identical (ICC 1 =ICC 2 =0.71). Diagnostic accuracy showed no significant differences (p=0.09-0.93) between v1 and v2 in any of the readers (range: A Z =0.78-0.88). PI-RADS scores show similar interreader agreement in v2 and v1 at comparable diagnostic performance. The simplification of the DCE interpretation in v2 might slightly improve agreement while not negatively affecting diagnostic performance. Copyright © 2017 Elsevier B.V. All rights reserved.

Obtaining systematic teacher reports of disruptive behavior disorders utilizing DSM-IV.

PubMed

Wolraich, M L; Feurer, I D; Hannah, J N; Baumgaertel, A; Pinnock, T Y

1998-04-01

This study examines the psychometric properties of the Vanderbilt AD/HD Diagnostic Teacher Rating Scale (VADTRS) and provides preliminary normative data from a large, geographically defined population. The VADTRS consists of the complete list of DSM-IV AD/HD symptoms, a screen for other disruptive behavior disorders, anxiety and depression, and ratings of academic and classroom behavior performance. Teachers in one suburban county completed the scale for their students during 2 consecutive years. Statistical methods included (a) exploratory and confirmatory latent variable analyses of item data, (b) evaluation of the internal consistency of the latent dimensions, (c) evaluation of latent structure concordance between school year samples, and (d) preliminary evaluation of criterion-related validity. The instrument comprises four behavioral dimensions and two performance dimensions. The behavioral dimensions were concordant between school years and were consistent with a priori DSM-IV diagnostic criteria. Correlations between latent dimensions and relevant, known disorders or problems varied from .25 to .66.

Comparison of Diagnostic Performance of Semi-Quantitative Knee Ultrasound and Knee Radiography with MRI: Oulu Knee Osteoarthritis Study.

PubMed

Podlipská, Jana; Guermazi, Ali; Lehenkari, Petri; Niinimäki, Jaakko; Roemer, Frank W; Arokoski, Jari P; Kaukinen, Päivi; Liukkonen, Esa; Lammentausta, Eveliina; Nieminen, Miika T; Tervonen, Osmo; Koski, Juhani M; Saarakkala, Simo

2016-03-01

Osteoarthritis (OA) is a common degenerative musculoskeletal disease highly prevalent in aging societies worldwide. Traditionally, knee OA is diagnosed using conventional radiography. However, structural changes of articular cartilage or menisci cannot be directly evaluated using this method. On the other hand, ultrasound is a promising tool able to provide direct information on soft tissue degeneration. The aim of our study was to systematically determine the site-specific diagnostic performance of semi-quantitative ultrasound grading of knee femoral articular cartilage, osteophytes and meniscal extrusion, and of radiographic assessment of joint space narrowing and osteophytes, using MRI as a reference standard. Eighty asymptomatic and 79 symptomatic subjects with mean age of 57.7 years were included in the study. Ultrasound performed best in the assessment of femoral medial and lateral osteophytes, and medial meniscal extrusion. In comparison to radiography, ultrasound performed better or at least equally well in identification of tibio-femoral osteophytes, medial meniscal extrusion and medial femoral cartilage morphological degeneration. Ultrasound provides relevant additional diagnostic information on tissue-specific morphological changes not depicted by conventional radiography. Consequently, the use of ultrasound as a complementary imaging tool along with radiography may enable more accurate and cost-effective diagnostics of knee osteoarthritis at the primary healthcare level.

Advanced error diagnostics of the CMAQ and Chimere modelling systems within the AQMEII3 model evaluation framework

EPA Science Inventory

The work here complements the overview analysis of the modelling systems participating in the third phase of the Air Quality Model Evaluation International Initiative (AQMEII3) by focusing on the performance for hourly surface ozone by two modelling systems, Chimere for Europe an...

[Evaluation of quality of HIV diagnostic procedures in Poland].

PubMed

Parczewski, Miłosz; Madaliński, Kazimierz; Leszczyszyn-Pynka, Magdalena; Boroń-Kaczmarska, Anna

2010-01-01

The aim of this work was quality assessment of HIV diagnostic procedures in Poland, including human and technical resources as well as laboratory practice. Sixty questionnaires were distributed among diagnostic centers to obtain qualitative data. Basing on the survey data serological control using coded panels of HIV-1/2 samples was performed. Thirty-one filled questionnaires were received (50.8%). Surveyed laboratories perform from 350 to 5500 serological screening tests per year. In most of laboratories fourth generation assays are available, while Blood Donation Centers screen the blood both with serological assays and by HIV-RNA detection. Sanitary and Epidemiological Stations and academic laboratories hold the ISO/IEC 17025 or IS0 9001:2001 accreditation, five of the surveyed centers participate in Labquality assurance and two in Quality Control in Molecular Diagnostics programs. Data of control serological testing were received from 21 centers. In the quality control assessment 194 analyses were performed with 91 true negative, 2 false negative, 96 true positive and 5 false positive results. False negative rate of % and false positive rate of 5.2% was noted for this study. Currently, virtually no guidelines related to the HIV-diagnostics quality assurance and control in Poland are in delineated. Development of the national unified quality control system, basing on the central institution is highly desirable. National certification within the frames of the quality control and assurance program should be mandatory for all the diagnostic labs, and aim at improvement of reliability of the result distributed among clinicians and patients.

Development and clinical evaluation of a rapid diagnostic kit for feline leukemia virus infection.

PubMed

Kim, Won-Shik; Chong, Chom-Kyu; Kim, Hak-Yong; Lee, Gyu-Cheol; Jeong, Wooseog; An, Dong-Jun; Jeoung, Hye-Young; Lee, Jae-In; Lee, Young-Ki

2014-01-01

Feline leukemia virus (FeLV) causes a range of neoplastic and degenerative diseases in cats. To obtain a more sensitive and convenient diagnosis of the disease, we prepared monoclonal antibodies specific for the FeLV p27 to develop a rapid diagnostic test with enhanced sensitivity and specificity. Among these antibodies, we identified two clones (hybridomas 8F8B5 and 8G7D1) that specifically bound to FeLV and were very suitable for a diagnostic kit. The affinity constants for 8F8B5 and 8G7D1 were 0.35 × 10⁸ and 0.86 × 10⁸, respectively. To investigate the diagnostic abilities of the rapid kit using these antibodies, we performed several clinical studies. Assessment of analytical sensitivity revealed that the detection threshold of the rapid diagnostic test was 2 ng/mL for recombinant p27 and 12.5 × 10⁴ IU/mL for FeLV. When evaluating 252 cat sera samples, the kit was found to have a kappa value of 0.88 compared to polymerase chain reaction (PCR), indicating a significant correlation between data from the rapid diagnostic test and PCR. Sensitivity and specificity of the kit were 95.2% (20/21) and 98.5% (257/261), respectively. Our results demonstrated that the rapid diagnostic test would be a suitable diagnostic tool for the rapid detection of FeLV infection in cats.

Evaluation of two commercially available chromogenic media for confirmation of methicillin-resistant Staphylococcus aureus from human, animal, and food samples.

PubMed

Ariza-Miguel, Jaime; Oniciuc, Elena-Alexandra; Sanz, Iván; Fernández-Natal, Isabel; Hernández, Marta; Rodríguez-Lázaro, David

2015-09-16

We compared the diagnostic performance of two chromogenic media, Brilliance MRSA 2 agar (Thermo Fisher Scientific) and ChromID MRSA agar (bioMérieux), for MRSA confirmation of 239 Staphylococcus aureus isolates from clinical, animal and food samples. Statistically significant differences were not observed between MRSA confirmation by mecA/mecC PCR, and by culture in both chromogenic media. However, a statistically significant difference was observed between the results obtained by both chromogenic media (p = 0.003). Segregated analysis of the results depending on the origin of the isolates (clinical, animal, and food) revealed a significant lower performance in the MRSA confirmation of food-derived isolates by using Brilliance MRSA 2 agar in comparison to PCR confirmation (p = 0.003) or ChromID MRSA agar (p<0.001). Both chromogenic media provided a good diagnostic performance for detection of MRSA isolates of human and animal origin. In conclusion, the use of chromogenic agar plates for MRSA confirmation of S. aureus isolates can provide a good diagnostic performance (sensitivity >92% and specificity >89%) regardless of the type of chromogenic media used or the origin of the S. aureus isolates. However, our results revealed a lower diagnostic performance for MRSA confirmation of S. aureus isolates from food samples by using Brilliance MRSA 2 agar. Copyright © 2015 Elsevier B.V. All rights reserved.

GUI Type Fault Diagnostic Program for a Turboshaft Engine Using Fuzzy and Neural Networks

NASA Astrophysics Data System (ADS)

Kong, Changduk; Koo, Youngju

2011-04-01

The helicopter to be operated in a severe flight environmental condition must have a very reliable propulsion system. On-line condition monitoring and fault detection of the engine can promote reliability and availability of the helicopter propulsion system. A hybrid health monitoring program using Fuzzy Logic and Neural Network Algorithms can be proposed. In this hybrid method, the Fuzzy Logic identifies easily the faulted components from engine measuring parameter changes, and the Neural Networks can quantify accurately its identified faults. In order to use effectively the fault diagnostic system, a GUI (Graphical User Interface) type program is newly proposed. This program is composed of the real time monitoring part, the engine condition monitoring part and the fault diagnostic part. The real time monitoring part can display measuring parameters of the study turboshaft engine such as power turbine inlet temperature, exhaust gas temperature, fuel flow, torque and gas generator speed. The engine condition monitoring part can evaluate the engine condition through comparison between monitoring performance parameters the base performance parameters analyzed by the base performance analysis program using look-up tables. The fault diagnostic part can identify and quantify the single faults the multiple faults from the monitoring parameters using hybrid method.

Addressing the Real-World Challenges in the Development of Propulsion IVHM Technology Experiment (PITEX)

NASA Technical Reports Server (NTRS)

Maul, William A.; Chicatelli, Amy; Fulton, Christopher E.; Balaban, Edward; Sweet, Adam; Hayden, Sandra Claire; Bajwa, Anupa

2005-01-01

The Propulsion IVHM Technology Experiment (PITEX) has been an on-going research effort conducted over several years. PITEX has developed and applied a model-based diagnostic system for the main propulsion system of the X-34 reusable launch vehicle, a space-launch technology demonstrator. The application was simulation-based using detailed models of the propulsion subsystem to generate nominal and failure scenarios during captive carry, which is the most safety-critical portion of the X-34 flight. Since no system-level testing of the X-34 Main Propulsion System (MPS) was performed, these simulated data were used to verify and validate the software system. Advanced diagnostic and signal processing algorithms were developed and tested in real-time on flight-like hardware. In an attempt to expose potential performance problems, these PITEX algorithms were subject to numerous real-world effects in the simulated data including noise, sensor resolution, command/valve talkback information, and nominal build variations. The current research has demonstrated the potential benefits of model-based diagnostics, defined the performance metrics required to evaluate the diagnostic system, and studied the impact of real-world challenges encountered when monitoring propulsion subsystems.

Diagnostic Criteria and Accuracy of Categorizing Malignant Thyroid Nodules by Ultrasonography and Ultrasound Elastography with Pathologic Correlation.

PubMed

Elsayed, Naglaa Mostafa; Elkhatib, Yasser Atta

2016-03-01

Thyroid nodules are a common medical and surgical concern. Thyroid ultrasound (US) is the primary imaging modality used for initial evaluation and assortment of nodules for fine needle aspiration (FNA) cytology/biopsy. Ultrasound elastography (USE) is believed to improve the diagnostic accuracy of US in distinguishing benign from malignant nodules. The aim of the work described here is to evaluate the diagnostic criteria and accuracy of US and USE in the diagnosis of malignant thyroid nodules. A prospective study of 88 patients who have thyroid nodules was performed. US, color Doppler, and USE were evaluated using a Philips iU22 equipped with a 5 to 12 MHz, linear transducer, followed by FNA of the each scanned nodule. The most sensitive US criteria for malignant nodules were a height-to-width ratio greater than one and the absence of a halo sign (sensitivity 0.875% and 1.000%, respectively). The most specific criteria for malignancy were a spiculated/blurred margin and the presence of microcalcifications (specificity 0.968% and 0.888%, respectively). The receiver operating characteristic curve showed that the cutoff diagnostic criteria of malignancy are two US characteristics and an elastography score of 4. The diagnostic accuracy of US for malignant thyroid nodules increases by combining US and USE. © The Author(s) 2015.

Yield of diagnostic procedures for invasive fungal infections in neutropenic febrile patients with chest computed tomography abnormalities.

PubMed

Ho, Dora Y; Lin, Margaret; Schaenman, Joanna; Rosso, Fernando; Leung, Ann N C; Coutre, Steven E; Sista, Ramachandra R; Montoya, Jose G

2011-01-01

Haematological patients with neutropenic fever are frequently evaluated with chest computed tomography (CT) to rule out invasive fungal infections (IFI). We retrospectively analysed data from 100 consecutive patients with neutropenic fever and abnormal chest CT from 1998 to 2005 to evaluate their chest CT findings and the yield of diagnostic approaches employed. For their initial CTs, 79% had nodular opacities, with 24.1% associated with the halo sign. Other common CT abnormalities included pleural effusions (48%), ground glass opacities (37%) and consolidation (31%). The CT findings led to a change in antifungal therapy in 54% of the patients. Fifty-six patients received diagnostic procedures, including 46 bronchoscopies, 25 lung biopsies and seven sinus biopsies, with a diagnostic yield for IFI of 12.8%, 35.0% and 83.3%, respectively. In conclusion, chest CT plays an important role in the evaluation of haematological patients with febrile neutropenia and often leads to a change in antimicrobial therapy. Pulmonary nodules are the most common radiological abnormality. Sinus or lung biopsies have a high-diagnostic yield for IFI as compared to bronchoscopy. Patients with IFI may not have sinus/chest symptoms, and thus, clinicians should have a low threshold for performing sinus/chest imaging, and if indicated and safe, a biopsy of the abnormal areas. © 2009 Blackwell Verlag GmbH.

Duplex recombinase polymerase amplification assays incorporating competitive internal controls for bacterial meningitis detection.

PubMed

Higgins, Owen; Clancy, Eoin; Forrest, Matthew S; Piepenburg, Olaf; Cormican, Martin; Boo, Teck Wee; O'Sullivan, Nicola; McGuinness, Claire; Cafferty, Deirdre; Cunney, Robert; Smith, Terry J

2018-04-01

Recombinase polymerase amplification (RPA) is an isothermal nucleic acid amplification technology that provides rapid and robust infectious disease pathogen detection, ideal for point-of-care (POC) diagnostics in disease-prevalent low-resource countries. We have developed and evaluated three duplex RPA assays incorporating competitive internal controls for the detection of leading bacterial meningitis pathogens. Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae singleplex RPA assays were initially developed and evaluated, demonstrating 100% specificity with limits of detection of 4.1, 8.5 and 3.9 genome copies per reaction, respectively. Each assay was further developed into internally controlled duplex RPA assays via the incorporation of internal amplification control templates. Clinical performance of each internally controlled duplex RPA assay was evaluated by testing 64 archived PCR-positive clinical samples. Compared to real-time PCR, all duplex RPA assays demonstrated 100% diagnostic specificity, with diagnostic sensitivities of 100%, 86.3% and 100% for the S. pneumoniae, N. meningitidis and H. influenzae assays, respectively. This study details the first report of internally controlled duplex RPA assays for the detection of bacterial meningitis pathogens: S. pneumoniae, N. meningitidis and H. influenzae. We have successfully demonstrated the clinical diagnostic utility of each duplex RPA assay, introducing effective diagnostic technology for POC bacterial meningitis identification in disease-prevalent developing countries. Copyright © 2018 Elsevier Inc. All rights reserved.

Magnetic resonance defecography versus videodefecography in the study of obstructed defecation syndrome: Is videodefecography still the test of choice after 50 years?

PubMed

Martín-Martín, G P; García-Armengol, J; Roig-Vila, J V; Espí-Macías, A; Martínez-Sanjuán, V; Mínguez-Pérez, M; Lorenzo-Liñán, M Á; Mulas-Fernández, C; González-Argenté, F X

2017-10-01

The aim of the present study was to evaluate the diagnostic accuracy of magnetic resonance (MR) defecography and compare it with videodefecography in the evaluation of obstructed defecation syndrome. This was a prospective cohort test accuracy study conducted at one major tertiary referral center on patients with a diagnosis of obstructed defecation syndrome who were referred to the colorectal surgery clinic in a consecutive series from 2009 to 2012. All patients underwent a clinical examination, videodefecography, and MR defecography in the supine position. We analyzed diagnostic accuracy for MR defecography and performed an agreement analysis using Cohen's kappa index (κ) for each diagnostic imaging examination performed with videodefecography and MR defecography. We included 40 patients with Rome III diagnostic criteria of obstructed defecation syndrome. The degree of agreement between the two tests was as follows: almost perfect for anismus (κ = 0.88) and rectal prolapse (κ = 0.83), substantial for enterocele (κ = 0.80) and rectocele grade III (κ = 0.65), moderate for intussusception (κ = 0.50) and rectocele grade II (κ = 0.49), and slight for rectocele grade I (κ = 0.30) and excessive perineal descent (κ = 0.22). Eighteen cystoceles and 11 colpoceles were diagnosed only by MR defecography. Most patients (54%) stated that videodefecography was the more uncomfortable test. MR defecography could become the imaging test of choice for evaluating obstructed defecation syndrome.

[Efficiency of saline contrast hysterosonography for evaluating the uterine cavity].

PubMed

de Kroon, C D; Jansen, F W; Trimbos, J B

2003-08-09

Diagnostic hysteroscopy is the standard investigation performed in the case of abnormal vaginal blood loss. More recently there has been increasing interest for minimal invasive saline contrast hysterosonography (SCHS) as this technique is less painful and less expensive. SCHS is indicated in case of abnormal uterine bleeding (premenopausal and postmenopausal), bleeding while using tamoxifen, suspicion of a congenital uterine abnormality and Asherman's syndrome. As well as intracavity abnormalities (polyps and myomas) SCHS can also be used to evaluate the intramural extension of myomas, which is necessary to assess whether hysteroscopic resection is possible. The sensitivity and specificity of SCHS for demonstrating intracavity abnormalities (with a prevalence of 54%) are 94% (95%-CI; 91-97) and 89% (95%-CI: 85-94) respectively. The positive and negative predictive values are 91% (95%-CI: 87-95) and 92% (95%-CI: 89-97) respectively. SCHS has a short learning curve and can be performed in an outpatient setting. SCHS fails more frequently in postmenopausal women than premenopausal women (12.5% vs. 4.7%; p = 0.03). The chance of a non-conclusive SCHS is 7.6% and is higher if the uterine volume is greater than 600 cm3 (relative risk: 2.63; 95%-CI: 1.05-6.60) and if two or more myomas are present: (RR 2.65; 95%-CI: 1.16-6.10). SCHS is 2 to 9 times cheaper than diagnostic hysteroscopy. It can replace 84% of the diagnostic hysteroscopies. SCHS, in combination with endometrial sampling, whenever indicated, might be able to replace diagnostic hysteroscopy as gold standard in the evaluation of the uterine cavity.

Investigation of Tapered Roller Bearing Damage Detection Using Oil Debris Analysis

NASA Technical Reports Server (NTRS)

Dempsey, Paula J.; Krieder, Gary; Fichter, Thomas

2006-01-01

A diagnostic tool was developed for detecting fatigue damage to tapered roller bearings. Tapered roller bearings are used in helicopter transmissions and have potential for use in high bypass advanced gas turbine aircraft engines. This diagnostic tool was developed and evaluated experimentally by collecting oil debris data from failure progression tests performed by The Timken Company in their Tapered Roller Bearing Health Monitoring Test Rig. Failure progression tests were performed under simulated engine load conditions. Tests were performed on one healthy bearing and three predamaged bearings. During each test, data from an on-line, in-line, inductance type oil debris sensor was monitored and recorded for the occurrence of debris generated during failure of the bearing. The bearing was removed periodically for inspection throughout the failure progression tests. Results indicate the accumulated oil debris mass is a good predictor of damage on tapered roller bearings. The use of a fuzzy logic model to enable an easily interpreted diagnostic metric was proposed and demonstrated.

[Diagnostic test scale SI5: Assessment of sacroiliac joint dysfunction].

PubMed

Acevedo González, Juan C; Quintero Oliveros, Silvia

2015-01-01

Sacroiliac joint dysfunction is a known cause of low back pain. We think that a diagnostic score scale (SI5) may be performed to assess diagnostic utility of clinical signs of sacroiliac joint dysfunction. The primary aim of the present study was to conduct the pilot study of our new diagnostic score scale, the SI5, for sacroiliac joint syndrome. We reviewed the literature on clinical characteristics, diagnostic tests and imaging most commonly used in diagnosing sacroiliac joint dysfunction. Our group evaluated the diagnostic utility of these aspects and we used those considered most representative to develop the SI5 diagnostic scale. The SI5 scale was applied to 22 patients with low back pain; afterwards, the standard test for diagnosing this pathology (selective blockage of the SI joint) was also performed on these patients. The sensitivity and specificity for each sign were also assessed and the diagnostic scale called SI5 was then proposed, based on these data. The most sensitive clinical tests for diagnosing SI joint dysfunction were 2 patient-reported clinical characteristics, the Laguerre Test, sacroiliac rocking test and Yeomans test (greater than 80% sensitivity). The tests with greatest diagnostic specificity (>80%) were the Lewitt test, Piedallu test and Gillet test. The proposed SI5 test score scale showed sensitivity of 73% and specificity of 71%. Sacroiliac joint syndrome has been shown to produce low back pain frequently; however, the diagnostic value of examination tests for sacroiliac joint pain has been questioned by other authors. The pilot study on the SI5 diagnostic score scale showed good sensitivity and specificity. However, the process of statistical validation of the SI5 needs to be continued. Copyright © 2014 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

An update of the appraisal of the accuracy and utility of cervical discography in chronic neck pain.

PubMed

Onyewu, Obi; Manchikanti, Laxmaiah; Falco, Frank J E; Singh, Vijay; Geffert, Stephanie; Helm, Standiford; Cohen, Steven P; Hirsch, Joshua A

2012-01-01

Chronic neck pain represents a significant public health problem. Despite high prevalence rates, there is a lack of consensus regarding the causes or treatments for this condition. Based on controlled evaluations, the cervical intervertebral discs, facet joints, and atlantoaxial joints have all been implicated as pain generators. Cervical provocation discography, which includes disc stimulation and morphological evaluation, is occasionally used to distinguish a painful disc from other potential sources of pain. Yet in the absence of validation and controlled outcome studies, the procedure remains mired in controversy. A systematic review of the diagnostic accuracy of cervical discography. To systematically evaluate and update the diagnostic accuracy of cervical discography. The available literature on cervical discography was reviewed. Methodological quality assessment of included studies was performed using Quality Appraisal of Reliability Studies (QAREL). Only diagnostic accuracy studies meeting at least 50% of the designated inclusion criteria were utilized for analysis. However, studies scoring less than 50% are presented descriptively and analyzed critically. The level of evidence was classified as good, fair, and limited or poor based on the quality of evidence developed by the U.S. Preventive Services Task Force (USPSTF).Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 to June 2012, and manual searches of the bibliographies of known primary and review articles. A total of 41 manuscripts were considered for accuracy and utility of cervical discography in chronic neck pain. There were 23 studies evaluating accuracy of discography. There were 3 studies meeting inclusion criteria for assessing the accuracy and prevalence of discography, with a prevalence of 16% to 53%. Based on modified Agency for Healthcare Research and Quality (AHRQ) accuracy evaluation and United States Preventive Services Task Force (USPSTF) level of evidence criteria, this systematic review indicates the strength of evidence is limited for the diagnostic accuracy of cervical discography. Limitations include a paucity of literature, poor methodological quality, and very few studies performed utilizing International Association for the Study of Pain (IASP) criteria. There is limited evidence for the diagnostic accuracy of cervical discography. Nevertheless, in the absence of any other means to establish a relationship between pathology and symptoms, cervical provocation discography may be an important evaluation tool in certain contexts to identify a subset of patients with chronic neck pain secondary to intervertebral disc disorders. Based on the current systematic review, cervical provocation discography performed according to the IASP criteria with control disc(s), and a minimum provoked pain intensity of 7 of 10, or at least 70% reproduction of worst pain (i.e. worst spontaneous pain of 7 = 7 x 70% = 5), may be a useful tool for evaluating chronic pain and cervical disc abnormalities in a small proportion of patients.

Going beyond a First Reader: A Machine Learning Methodology for Optimizing Cost and Performance in Breast Ultrasound Diagnosis.

PubMed

Venkatesh, Santosh S; Levenback, Benjamin J; Sultan, Laith R; Bouzghar, Ghizlane; Sehgal, Chandra M

2015-12-01

The goal of this study was to devise a machine learning methodology as a viable low-cost alternative to a second reader to help augment physicians' interpretations of breast ultrasound images in differentiating benign and malignant masses. Two independent feature sets consisting of visual features based on a radiologist's interpretation of images and computer-extracted features when used as first and second readers and combined by adaptive boosting (AdaBoost) and a pruning classifier resulted in a very high level of diagnostic performance (area under the receiver operating characteristic curve = 0.98) at a cost of pruning a fraction (20%) of the cases for further evaluation by independent methods. AdaBoost also improved the diagnostic performance of the individual human observers and increased the agreement between their analyses. Pairing AdaBoost with selective pruning is a principled methodology for achieving high diagnostic performance without the added cost of an additional reader for differentiating solid breast masses by ultrasound. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Performance of an HRP-2 Rapid Diagnostic Test in Nigerian Children Less Than 5 Years of Age

PubMed Central

Ajumobi, Olufemi; Sabitu, Kabir; Nguku, Patrick; Kwaga, Jacob; Ntadom, Godwin; Gitta, Sheba; Elizeus, Rutebemberwa; Oyibo, Wellington; Nsubuga, Peter; Maire, Mark; Poggensee, Gabriele

2015-01-01

The diagnostic performance of histidine-rich protein 2 (HRP-2)–based malaria rapid diagnostic test (RDT) was evaluated in a mesoendemic area for malaria, Kaduna, Nigeria. We compared RDT results with expert microscopy results of blood samples from 295 febrile children under 5 years. Overall, 11.9% (35/295) tested positive with RDT compared with 10.5% (31/295) by microscopy: sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 100%, 98.5%, 88.6%, and 100%, respectively. The RDT sensitivity was not affected by transmission season, parasite density, and age. Specificity and positive PV decreased slightly during the high-transmission season (97.5% and 83.3%). The RDT test positivity rates in the low- and high-transmission seasons were 9.4% and 13.5%, respectively. Overall, the test performance of this RDT was satisfactory. The findings of a low proportion of RDT false positives, no invalid and no false-negative results should validate the performance of RDTs in this context. PMID:25711608

IOTA simple rules in differentiating between benign and malignant ovarian tumors.

PubMed

Tantipalakorn, Charuwan; Wanapirak, Chanane; Khunamornpong, Surapan; Sukpan, Kornkanok; Tongsong, Theera

2014-01-01

To evaluate the diagnostic performance of IOTA simple rules in differentiating between benign and malignant ovarian tumors. A study of diagnostic performance was conducted on women scheduled for elective surgery due to ovarian masses between March 2007 and March 2012. All patients underwent ultrasound examination for IOTA simple rules within 24 hours of surgery. All examinations were performed by the authors, who had no any clinical information of the patients, to differentiate between benign and malignant adnexal masses using IOTA simple rules. Gold standard diagnosis was based on pathological or operative findings. A total of 398 adnexal masses, in 376 women, were available for analysis. Of them, the IOTA simple rules could be applied in 319 (80.1%) including 212 (66.5%) benign tumors and 107 (33.6%) malignant tumors. The simple rules yielded inconclusive results in 79 (19.9%) masses. In the 319 masses for which the IOTA simple rules could be applied, sensitivity was 82.9% and specificity 95.3%. The IOTA simple rules have high diagnostic performance in differentiating between benign and malignant adnexal masses. Nevertheless, inconclusive results are relatively common.

Delirium diagnosis defined by cluster analysis of symptoms versus diagnosis by DSM and ICD criteria: diagnostic accuracy study.

PubMed

Sepulveda, Esteban; Franco, José G; Trzepacz, Paula T; Gaviria, Ana M; Meagher, David J; Palma, José; Viñuelas, Eva; Grau, Imma; Vilella, Elisabet; de Pablo, Joan

2016-05-26

Information on validity and reliability of delirium criteria is necessary for clinicians, researchers, and further developments of DSM or ICD. We compare four DSM and ICD delirium diagnostic criteria versions, which were developed by consensus of experts, with a phenomenology-based natural diagnosis delineated using cluster analysis of delirium features in a sample with a high prevalence of dementia. We also measured inter-rater reliability of each system when applied by two evaluators from distinct disciplines. Cross-sectional analysis of 200 consecutive patients admitted to a skilled nursing facility, independently assessed within 24-48 h after admission with the Delirium Rating Scale-Revised-98 (DRS-R98) and for DSM-III-R, DSM-IV, DSM-5, and ICD-10 criteria for delirium. Cluster analysis (CA) delineated natural delirium and nondelirium reference groups using DRS-R98 items and then diagnostic systems' performance were evaluated against the CA-defined groups using logistic regression and crosstabs for discriminant analysis (sensitivity, specificity, percentage of subjects correctly classified by each diagnostic system and their individual criteria, and performance for each system when excluding each individual criterion are reported). Kappa Index (K) was used to report inter-rater reliability for delirium diagnostic systems and their individual criteria. 117 (58.5 %) patients had preexisting dementia according to the Informant Questionnaire on Cognitive Decline in the Elderly. CA delineated 49 delirium subjects and 151 nondelirium. Against these CA groups, delirium diagnosis accuracy was highest using DSM-III-R (87.5 %) followed closely by DSM-IV (86.0 %), ICD-10 (85.5 %) and DSM-5 (84.5 %). ICD-10 had the highest specificity (96.0 %) but lowest sensitivity (53.1 %). DSM-III-R had the best sensitivity (81.6 %) and the best sensitivity-specificity balance. DSM-5 had the highest inter-rater reliability (K =0.73) while DSM-III-R criteria were the least reliable. Using our CA-defined, phenomenologically-based delirium designations as the reference standard, we found performance discordance among four diagnostic systems when tested in subjects where comorbid dementia was prevalent. The most complex diagnostic systems have higher accuracy and the newer DSM-5 have higher reliability. Our novel phenomenological approach to designing a delirium reference standard may be preferred to guide revisions of diagnostic systems in the future.

How to perform a critically appraised topic: part 2, appraise, evaluate, generate, and recommend.

PubMed

Kelly, Aine Marie; Cronin, Paul

2011-11-01

This article continues the discussion of a critically appraised topic started in Part 1. A critically appraised topic is a practical tool for learning and applying critical appraisal skills. This article outlines steps 4-7 involved in performing a critically appraised topic for studies of diagnostic tests: Appraise, Appraise the literature; Evaluate, evaluate the strength of the evidence from the literature; Generate, generate graphs of conditional probability; and Recommend, draw conclusions and make recommendations. For steps 4-7 of performing a critically appraised topic, the main study results are summarized and translated into clinically useful measures of accuracy, efficacy, or risk.

Diagnosis of Caprine Arthritis Encephalitis Virus infection in dairy goats by ELISA, PCR and Viral Culture.

PubMed

Panneum, S; Rukkwamsuk, T

2017-03-01

For preventive and control strategies of Caprine Arthritis Encephalitis Virus (CAEV) infection in dairy goats, performance of the available diagnostic tests was described as one of the most important and necessary aspects. The study aimed at evaluating the diagnostic test performance, including PCR, ELISA and viral culture, for CAEV infection in dairy goats in Thailand. Blood samples of 29 dairy goats from five low- to medium-prevalence herds and one very low-prevalence herd were collected for PCR and ELISA methods. The performance of these two diagnostic methods was evaluated by comparing with cytopathic effects (CPE) in the co-cultivation of CAEV and primary synovial cells. Results indicated that sensitivity, specificity were, respectively, 69.6%, 100%, for PCR; and 95.7%, 83.3% for ELISA. The PCR assay tended to have lower sensitivity and higher specificity than ELISA. When multiple tests were applied, parallel testing provided sensitivity and specificity of 98.7% and 83.3%, while series testing showed sensitivity and specificity of 66.6% and 100% respectively. These results indicated that combination of ELISA and PCR provided some advantages and possibly offered optimal methods to detect CAEV-infected goats. Kappa value of the agreement between PCR and ELISA test was 0.34, indicating fair agreement. Regarding the possibility of antigenic variation between CAEV strains used in both PCR and ELISA assays, the actual circulating CAEV strain should be reviewed in order to develop and enhance the diagnostic tests using the CAE viral antigens derived from specific local strains of Thailand.

Agreement of glaucoma specialists and experienced optometrists in gonioscopy and optic disc evaluation

PubMed Central

Kumar, Addepalli U.; Jonnadula, Ganesh B.; Garudadri, Chandrasekhar; Rao, Harsha L.; Senthil, Sirisha; Papas, Eric B.; Sankaridurg, Padmaja; Khanna, Rohit C.

2013-01-01

Purpose To compare the diagnostic performance of glaucoma specialists and experienced optometrists in gonioscopy and optic disc assessment. Methods This study was done to validate the diagnostic performance of two experienced optometrists for using their skills of detecting glaucoma using gonioscopy and optic disc assessment in a major epidemiological study, the L V Prasad Eye Institute Glaucoma Epidemiology and Molecular Genetics Study (LVPEI-GLEAMS). Gonioscopic findings for 150 eyes were categorized as 0, 1 and 2 for open angle, primary angle closure suspect (PACS) and primary angle closure (PAC) respectively. Optic disc findings for 200 eyes were categorized as 0, 1 and 2 for normal, suspects and glaucomatous respectively. Weighted kappa (κ) and diagnostic accuracy parameters were calculated. Two optometrists (#1 and #2) participated in the study. Results Agreement between glaucoma specialists and optometrist for interpretation of gonioscopy to discriminate PACS and PAC from open angles and for interpretation of optic disc to discriminate glaucomatous and suspicious discs from normal, the kappa (κ) was 0.92 and 0.84 and 0.90 and 0.89 for optometrists #1 and #2 respectively. Sensitivities and specificities were above 90% for gonioscopy. Optic disc evaluation had specificities greater than 95% to discriminate normal from glaucomatous discs while the sensitivities were 83% and 93% for optometrists #1 and #2 respectively. Conclusion Agreement between optometrists and glaucoma specialists, in diagnostic performance of gonioscopy and optic assessment was excellent with high sensitivity and specificity. Hence, we conclude that the experienced optometrists can detect glaucoma accurately in the LVPEI-GLEAMS.

Diagnostic performance of optical coherence tomography ganglion cell--inner plexiform layer thickness measurements in early glaucoma.

PubMed

Mwanza, Jean-Claude; Budenz, Donald L; Godfrey, David G; Neelakantan, Arvind; Sayyad, Fouad E; Chang, Robert T; Lee, Richard K

2014-04-01

To evaluate the glaucoma diagnostic performance of ganglion cell inner-plexiform layer (GCIPL) parameters used individually and in combination with retinal nerve fiber layer (RNFL) or optic nerve head (ONH) parameters measured with Cirrus HD-OCT (Carl Zeiss Meditec, Inc, Dublin, CA). Prospective cross-sectional study. Fifty patients with early perimetric glaucoma and 49 age-matched healthy subjects. Three peripapillary RNFL and 3 macular GCIPL scans were obtained in 1 eye of each participant. A patient was considered glaucomatous if at least 2 of the 3 RNFL or GCIPL scans had the average or at least 1 sector measurement flagged at 1% to 5% or less than 1%. The diagnostic performance was determined for each GCIPL, RNFL, and ONH parameter as well as for binary or-logic and and-logic combinations of GCIPL with RNFL or ONH parameters. Sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR). Among GCIPL parameters, the minimum had the best diagnostic performance (sensitivity, 82.0%; specificity, 87.8%; PLR, 6.69; and NLR, 0.21). Inferior quadrant was the best RNFL parameter (sensitivity, 74%; specificity, 95.9%; PLR, 18.13; and NLR, 0.27), as was rim area (sensitivity, 68%; specificity, 98%; PLR, 33.3; and NLR, 0.33) among ONH parameters. The or-logic combination of minimum GCIPL and average RNFL provided the overall best diagnostic performance (sensitivity, 94%; specificity, 85.7%; PRL, 6.58; and NLR, 0.07) as compared with the best RNFL, best ONH, and best and-logic combination (minimum GCIPL and inferior quadrant RNFL; sensitivity, 64%; specificity, 100%; PLR, infinity; and NPR, 0.36). The binary or-logic combination of minimum GCIPL and average RNFL or rim area provides better diagnostic performances than those of and-logic combinations or best single GCIPL, RNFL, or ONH parameters. This finding may be clinically valuable for the diagnosis of early glaucoma. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Comparison of isolated-check visual evoked potential and standard automated perimetry in early glaucoma and high-risk ocular hypertension

PubMed Central

Chen, Xiang-Wu; Zhao, Ying-Xi

2017-01-01

AIM To compare the diagnostic performance of isolated-check visual evoked potential (icVEP) and standard automated perimetry (SAP), for evaluating the application values of icVEP in the detection of early glaucoma. METHODS Totally 144 subjects (288 eyes) were enrolled in this study. icVEP testing was performed with the Neucodia visual electrophysiological diagnostic system. A 15% positive-contrast (bright) condition pattern was used in this device to differentiate between glaucoma patients and healthy control subjects. Signal-to-noise ratios (SNR) were derived based on a multivariate statistic. The eyes were judged as abnormal if the test yielded an SNR≤1. SAP testing was performed with the Humphrey Field Analyzer II. The visual fields were deemed as abnormality if the glaucoma hemifield test results outside normal limits; or the pattern standard deviation with P<0.05; or the cluster of three or more non-edge points on the pattern deviation plot in a single hemifield with P<0.05, one of which must have a P<0.01. Disc photographs were graded as either glaucomatous optic neuropathy or normal by two experts who were masked to all other patient information. Moorfields regression analysis (MRA) used as a separate diagnostic classification was performed by Heidelberg retina tomograph (HRT). RESULTS When the disc photograph grader was used as diagnostic standard, the sensitivity for SAP and icVEP was 32.3% and 38.5% respectively and specificity was 82.3% and 77.8% respectively. When the MRA Classifier was used as the diagnostic standard, the sensitivity for SAP and icVEP was 48.6% and 51.4% respectively and specificity was 84.1% and 78.0% respectively. When the combined structural assessment was used as the diagnostic standard, the sensitivity for SAP and icVEP was 59.2% and 53.1% respectively and specificity was 84.2% and 84.6% respectivlely. There was no statistical significance between the sensitivity or specificity of SAP and icVEP, regardless of which diagnostic standard was based on. CONCLUSION The diagnostic performance of icVEP is not better than that of SAP in the detection of early glaucoma. PMID:28503434

Diagnostic value of potassium level in a spot urine sample as an index of 24-hour urinary potassium excretion in unselected patients hospitalized in a hypertension unit

PubMed Central

Symonides, Bartosz; Wojciechowska, Ewa; Gryglas, Adam; Gaciong, Zbigniew

2017-01-01

Background Primary hyperaldosteronism may be associated with elevated 24-hour urinary potassium excretion. We evaluated the diagnostic value of spot urine (SU) potassium as an index of 24-hour urinary potassium excretion. Methods We measured SU and 24-hour urinary collection potassium and creatinine in 382 patients. Correlations between SU and 24-hour collections were assessed for potassium levels and potassium/creatinine ratios. We used the PAHO formula to estimate 24-hour urinary potassium excretion based on SU potassium level. The agreement between estimated and measured 24-hour urinary potassium excretion was evaluated using the Bland-Altman method. To evaluate diagnostic performance of SU potassium, we calculated areas under the curve (AUC) for SU potassium/creatinine ratio and 24-hour urinary potassium excretion estimated using the PAHO formula. Results Strongest correlation between SU and 24-hour collection was found for potassium/creatinine ratio (r = 0.69, P<0.001). The PAHO formula underestimated 24-hour urinary potassium excretion by mean 8.3±18 mmol/d (95% limits of agreement -28 to +44 mmol/d). Diagnostic performance of SU potassium/creatinine ratio was borderline good only if 24-hour urinary potassium excretion was largely elevated (AUC 0.802 for 120 mmol K+/24 h) but poor with lower values (AUC 0.696 for 100 mmol K+/24 h, 0.636 for 80 mmol K+/24 h, 0.675 for 40 mmol K+/24 h). Diagnostic performance of 24-hour urinary potassium excretion estimated by the PAHO formula was excellent with values above 120 mmol/d and good with lower values (AUC 0.941 for 120 mmol K+/24 h, 0.819 for 100 mmol K+/24 h, 0.823 for 80 mmol K+/24 h, 0.836 for 40 mmol K+/24 h). Conclusions Spot urine potassium/creatinine ratio might be a marker of increased 24-hour urinary potassium excretion and a potentially useful screening test when reliable 24-hour urine collection is not available. The PAHO formula allowed estimation of the 24-hour urinary potassium excretion based on SU measurements with reasonable clinical accuracy. PMID:28662194

Diagnostic accuracy of a noninvasive hepatic ultrasound score for non-alcoholic fatty liver disease (NAFLD) in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

PubMed

Goulart, Alessandra Carvalho; Oliveira, Ilka Regina Souza de; Alencar, Airlane Pereira; Santos, Maira Solange Camara dos; Santos, Itamar Souza; Martines, Brenda Margatho Ramos; Meireles, Danilo Peron; Martines, João Augusto dos Santos; Misciagna, Giovanni; Benseñor, Isabela Martins; Lotufo, Paulo Andrade

2015-01-01

Noninvasive strategies for evaluating non-alcoholic fatty liver disease (NAFLD) have been investigated over the last few decades. Our aim was to evaluate the diagnostic accuracy of a new hepatic ultrasound score for NAFLD in the ELSA-Brasil study. Diagnostic accuracy study conducted in the ELSA center, in the hospital of a public university. Among the 15,105 participants of the ELSA study who were evaluated for NAFLD, 195 individuals were included in this sub-study. Hepatic ultrasound was performed (deep beam attenuation, hepatorenal index and anteroposterior diameter of the right hepatic lobe) and compared with the hepatic steatosis findings from 64-channel high-resolution computed tomography (CT). We also evaluated two clinical indices relating to NAFLD: the fatty liver index (FLI) and the hepatic steatosis index (HSI). Among the 195 participants, the NAFLD frequency was 34.4%. High body mass index, high waist circumference, diabetes and hypertriglyceridemia were associated with high hepatic attenuation and large anteroposterior diameter of the right hepatic lobe, but not with the hepatorenal index. The hepatic ultrasound score, based on hepatic attenuation and the anteroposterior diameter of the right hepatic lobe, presented the best performance for NAFLD screening at the cutoff point ≥ 1 point; sensitivity: 85.1%; specificity: 73.4%; accuracy: 79.3%; and area under the curve (AUC 0.85; 95% confidence interval, CI: 0.78-0.91)]. FLI and HSI presented lower performance (AUC 0.76; 95% CI: 0.69-0.83) than CT. The hepatic ultrasound score based on hepatic attenuation and the anteroposterior diameter of the right hepatic lobe has good reproducibility and accuracy for NAFLD screening.

Occult gastrointestinal bleeding. An evaluation of available diagnostic methods.

PubMed

Richardson, J D; McInnis, W D; Ramos, R; Aust, J B

1975-05-01

Occult gastrointestinal bleeding was defined as continued bleeding in spite of a normal series of roentgenorgrams of the upper part of the gastrointestinal tract, barium enema, and sigmoidoscopy. Twenty-six such patients were treated. A thorough systematic evaluation, including gastroscopy, colonoscopy, visceral angiography, and isotopic scanning, was done preoperatively. Using colonoscopy and arteriography, nearly 60% of the bleeding sites were identified. Seventy-six percent of the lesions identified were in the terminal part of the ileum or the ascending colon. Exploratory laparotomy should be performed for life-threatening hemorrhage or as a diagnostic test only after a thorough preoperative evaluation. If results of a complete preoperative evaluation including arteriography were normal, then the likelihood of finding a discrete cause of bleeding at laparotomy was high (80%). A systematic evaluation and diligence of both physcian and patient in localizing the site of bleeding are essential.

Diagnostic Methods for Predicting Performance Impairment Associated with Combat Stress

DTIC Science & Technology

2007-08-01

vision. Participants who wore glasses were excluded, as the frame of eyeglasses interfered with the ability to acquire a signal with the apparatus...TCD in monitoring fitness to perform concurrently with performance, and to explore strategies for using TCD as a predictor of future performance...most effective technique for evaluating whether soldiers are fit for missions requiring sustained attention. The aim of this study was to test

Portable Health Algorithms Test System

NASA Technical Reports Server (NTRS)

Melcher, Kevin J.; Wong, Edmond; Fulton, Christopher E.; Sowers, Thomas S.; Maul, William A.

2010-01-01

A document discusses the Portable Health Algorithms Test (PHALT) System, which has been designed as a means for evolving the maturity and credibility of algorithms developed to assess the health of aerospace systems. Comprising an integrated hardware-software environment, the PHALT system allows systems health management algorithms to be developed in a graphical programming environment, to be tested and refined using system simulation or test data playback, and to be evaluated in a real-time hardware-in-the-loop mode with a live test article. The integrated hardware and software development environment provides a seamless transition from algorithm development to real-time implementation. The portability of the hardware makes it quick and easy to transport between test facilities. This hard ware/software architecture is flexible enough to support a variety of diagnostic applications and test hardware, and the GUI-based rapid prototyping capability is sufficient to support development execution, and testing of custom diagnostic algorithms. The PHALT operating system supports execution of diagnostic algorithms under real-time constraints. PHALT can perform real-time capture and playback of test rig data with the ability to augment/ modify the data stream (e.g. inject simulated faults). It performs algorithm testing using a variety of data input sources, including real-time data acquisition, test data playback, and system simulations, and also provides system feedback to evaluate closed-loop diagnostic response and mitigation control.

[Diagnostic value of a predictive model for complete ruptures of the rotator cuff associated to subacromial impingement].

PubMed

Águila-Ledesma, I R; Córdova-Fonseca, J L; Medina-Pontaza, O; Núñez-Gómez, D A; Calvache-García, C; Pérez-Atanasio, J M; Torres-González, R

2017-01-01

Pathology related to the rotator cuff remains among the most prevalent musculoskeletal diseases. There is an increasing need for imaging studies (MRI, US, arthroscopy) to test the diagnostic performance of the medical history and physical examination. To prove the diagnostic value of a clinical-radiographic predictive model to find complete ruptures of the rotator cuff. Descriptive, observational, prospective, transversal and analytical study. Fifty-five patients with preoperative shoulder pain were evaluated with 13 predictive variables: age > 50 years, nocturnal pain, muscle weakness, clinical signs of Neer, Hawkins, Jobe, external rotation lag (ERLS), belly-press, bear hug, and lift-off, radiographic measurement of subacromial space, acromial index and critical shoulder angle. Sensitivity, specificity, and positive and negative predictive values were measured in each variable, comparing the results of each one against the postoperative findings. Of the 55 patients evaluated, 42 had a complete rupture of the rotator cuff in the postoperative period. The eight variables with a higher diagnostic value were selected and a ROC curve was performed, providing an area under the curve of 0.88. This predictive model uses eight variables (age > 50 years, nocturnal pain, muscle weakness, Jobe, Hawkins, ERLS, subacromial space ≤ 6 mm, and critical shoulder angle > 35°), which together add the predictive value of 0.88 (AUC) to diagnose complete ruptures of the supraspinatus tendon.

Combination of two-dimensional shear wave elastography with ultrasound breast imaging reporting and data system in the diagnosis of breast lesions: a new method to increase the diagnostic performance.

PubMed

Li, Dan-Dan; Xu, Hui-Xiong; Guo, Le-Hang; Bo, Xiao-Wan; Li, Xiao-Long; Wu, Rong; Xu, Jun-Mei; Zhang, Yi-Feng; Zhang, Kun

2016-09-01

To evaluate the diagnostic performance of a new method of combined two-dimensional shear wave elastography (i.e. virtual touch imaging quantification, VTIQ) and ultrasound (US) Breast Imaging Reporting and Data System (BI-RADS) in the differential diagnosis of breast lesions. From September 2014 to December 2014, 276 patients with 296 pathologically proven breast lesions were enrolled in this study. The conventional US images were interpreted by two independent readers. The diagnosis performances of BI-RADS and combined BI-RADS and VTIQ were evaluated, including the area under the receiver operating characteristic curve (AUROC), sensitivity and specificity. Observer consistency was also evaluated. Pathologically, 212 breast lesions were benign and 84 were malignant. Compared with BI-RADS alone, the AUROCs and specificities of the combined method for both readers increased significantly (AUROC: 0.862 vs. 0.693 in reader 1, 0.861 vs. 0.730 in reader 2; specificity: 91.5 % vs. 38.7 % in reader 1, 94.8 % vs. 47.2 % in reader 2; all P < .05). The Kappa value between the two readers for BI-RADS assessment was 0.614, and 0.796 for the combined method. The combined VTIQ and BI-RADS had a better diagnostic performance in the diagnosis of breast lesions in comparison with BI-RADS alone. • Combination of conventional ultrasound and elastography distinguishes breast cancers more effectively. • Combination of conventional ultrasound and elastography increases observer consistency. • BI-RADS weights more than the 2D-SWE with an increase in malignancy probability.

Accuracy of computer-aided diagnosis based on narrow-band imaging endocytoscopy for diagnosing colorectal lesions: comparison with experts.

PubMed

Misawa, Masashi; Kudo, Shin-Ei; Mori, Yuichi; Takeda, Kenichi; Maeda, Yasuharu; Kataoka, Shinichi; Nakamura, Hiroki; Kudo, Toyoki; Wakamura, Kunihiko; Hayashi, Takemasa; Katagiri, Atsushi; Baba, Toshiyuki; Ishida, Fumio; Inoue, Haruhiro; Nimura, Yukitaka; Oda, Msahiro; Mori, Kensaku

2017-05-01

Real-time characterization of colorectal lesions during colonoscopy is important for reducing medical costs, given that the need for a pathological diagnosis can be omitted if the accuracy of the diagnostic modality is sufficiently high. However, it is sometimes difficult for community-based gastroenterologists to achieve the required level of diagnostic accuracy. In this regard, we developed a computer-aided diagnosis (CAD) system based on endocytoscopy (EC) to evaluate cellular, glandular, and vessel structure atypia in vivo. The purpose of this study was to compare the diagnostic ability and efficacy of this CAD system with the performances of human expert and trainee endoscopists. We developed a CAD system based on EC with narrow-band imaging that allowed microvascular evaluation without dye (ECV-CAD). The CAD algorithm was programmed based on texture analysis and provided a two-class diagnosis of neoplastic or non-neoplastic, with probabilities. We validated the diagnostic ability of the ECV-CAD system using 173 randomly selected EC images (49 non-neoplasms, 124 neoplasms). The images were evaluated by the CAD and by four expert endoscopists and three trainees. The diagnostic accuracies for distinguishing between neoplasms and non-neoplasms were calculated. ECV-CAD had higher overall diagnostic accuracy than trainees (87.8 vs 63.4%; [Formula: see text]), but similar to experts (87.8 vs 84.2%; [Formula: see text]). With regard to high-confidence cases, the overall accuracy of ECV-CAD was also higher than trainees (93.5 vs 71.7%; [Formula: see text]) and comparable to experts (93.5 vs 90.8%; [Formula: see text]). ECV-CAD showed better diagnostic accuracy than trainee endoscopists and was comparable to that of experts. ECV-CAD could thus be a powerful decision-making tool for less-experienced endoscopists.

Iridology: A systematic review.

PubMed

Ernst, E

1999-02-01

Iridologists claim to be able to diagnose medical conditions through abnormalities of pigmentation in the iris. This technique is popular in many countries. Therefore it is relevant to ask whether it is valid. To systematically review all interpretable tests of the validity of iridology as a diagnostic tool. DATA SOURCE AND EXTRACTION: Three independent literature searches were performed to identify all blinded tests. Data were extracted in a predefined, standardized fashion. Four case control studies were found. The majority of these investigations suggests that iridology is not a valid diagnostic method. The validity of iridology as a diagnostic tool is not supported by scientific evaluations. Patients and therapists should be discouraged from using this method.

Gastroscopy: a primary diagnostic procedure.

PubMed

Coleman, W H

1988-03-01

EGD, using 1986 models of either the fiberoptic gastroscope or the videoscope, is a safe and accurate procedure that can be performed by any physician trained in the technique of endoscope passage. It may be performed at large medical centers or small rural hospitals, outpatient clinics, or even private offices. Patients themselves have indicated preference for endoscopic evaluation over the double-contrast barium meal after they have experienced both procedures. The short time of procedure, its accuracy, safety, and its relative lack of discomfort to the patient lend it readily to being an initial component in the primary evaluation of symptoms of abdominal distress, gastrointestinal bleeding, dysphagia, esophageal reflux, persistent vomiting, and odynophagia. It is essential in the evaluation of complications of esophageal reflux and the evaluation of abnormal radiological findings in the upper gastrointestinal tract. It should never be overlooked in evaluating the patient with iron deficiency anemia of unknown etiology. Economic pressures have already moved EGD from the surgery wards to endoscopy labs and to the outpatient setting. These same forces will project more physicians into the role of the diagnostic endoscopist and the patient will benefit by decreased medical costs, quicker diagnosis and treatment, and enhanced continuity of care.

Accuracy of physical examination for chronic lumbar radiculopathy

PubMed Central

2013-01-01

Background Clinical examination of patients with chronic lumbar radiculopathy aims to clarify whether there is nerve root impingement. The aims of this study were to investigate the association between findings at clinical examination and nerve root impingement, to evaluate the accuracy of clinical index tests in a specialised care setting, and to see whether imaging clarifies the cause of chronic radicular pain. Methods A total of 116 patients referred with symptoms of lumbar radiculopathy lasting more than 12 weeks and at least one positive index test were included. The tests were the straight leg raising test, and tests for motor muscle strength, dermatome sensory loss, and reflex impairment. Magnetic resonance imaging (n = 109) or computer tomography (n = 7) were imaging reference standards. Images were analysed at the level of single nerve root(s), and nerve root impingement was classified as present or absent. Sensitivities, specificities, and positive and negative likelihood ratios (LR) for detection of nerve root impingement were calculated for each individual index test. An overall clinical evaluation, concluding on the level and side of the radiculopathy, was performed. Results The prevalence of disc herniation was 77.8%. The diagnostic accuracy of individual index tests was low with no tests reaching positive LR >4.0 or negative LR <0.4. The overall clinical evaluation was slightly more accurate, with a positive LR of 6.28 (95% CI 1.06–37.21) for L4, 1.74 (95% CI 1.04–2.93) for L5, and 1.29 (95% CI 0.97–1.72) for S1 nerve root impingement. An overall clinical evaluation, concluding on the level and side of the radiculopathy was also performed, and receiver operating characteristic (ROC) analysis with area under the curve (AUC) calculation for diagnostic accuracy of this evaluation was performed. Conclusions The accuracy of individual clinical index tests used to predict imaging findings of nerve root impingement in patients with chronic lumbar radiculopathy is low when applied in specialised care, but clinicians’ overall evaluation improves diagnostic accuracy slightly. The tests are not very helpful in clarifying the cause of radicular pain, and are therefore inaccurate for guidance in the diagnostic workup of the patients. The study population was highly selected and therefore the results from this study should not be generalised to unselected patient populations in primary care nor to even more selected surgical populations. PMID:23837886

Utility of conventional transbronchial needle aspiration with rapid on-site evaluation (c-TBNA-ROSE) at a tertiary care center with endobronchial ultrasound (EBUS) facility

PubMed Central

Madan, Neha Kawatra; Madan, Karan; Jain, Deepali; Walia, Ritika; Mohan, Anant; Hadda, Vijay; Mathur, Sandeep; Iyer, Venkateswaran K; Khilnani, Gopi C; Guleria, Randeep

2016-01-01

Background: Conventional transbronchial needle aspiration (c-TBNA) is an underutilized bronchoscopic modality. Endobronchial ultrasound (EBUS) guided-TBNA though efficacious is an expensive modality, facilities of which are available at only limited centers. c-TBNA is cost-effective and has potential for wide utilization especially in resource-limited settings. Rapid on-site evaluation (ROSE) improves the yield of c-TBNA. Materials and Methods: A retrospective review of the bronchoscopy records (May 2012 to July 2014) was performed. The patients who underwent c-TBNA with ROSE were included in the study and their clinical details were extracted. Convex probe EBUS-TBNA was being regularly performed during the study period by the operators performing c-TBNA. Results: c-TBNA with ROSE was performed in 41 patients with mean age of 42.4 (16.2) years. The most frequently sampled node stations (>90% patients) were the subcarinal and lower right paratracheal. Representative samples could be obtained in 33 out of the 41 patients (80.4%). c-TBNA was diagnostic in 32 [tuberculosis (TB)-8, sarcoidosis-9, and malignancy-15] patients out of the 41 patients. The overall diagnostic yield (sensitivity) of c-TBNA with ROSE was 78%. Mean procedure duration was 18.4 (3.1) min and there were no procedural complications. Conclusion: c-TBNA with ROSE is a safe, efficacious, and cost-effective bronchoscopic modality. When it was performed by operators routinely performing EBUS-TBNA, diagnostic yields similar to that of EBUS-TBNA can be obtained. Even at the centers where EBUS facilities are available, c-TBNA should be routinely performed. PMID:27011437

Quality and reporting of diagnostic accuracy studies in TB, HIV and malaria: evaluation using QUADAS and STARD standards.

PubMed

Fontela, Patricia Scolari; Pant Pai, Nitika; Schiller, Ian; Dendukuri, Nandini; Ramsay, Andrew; Pai, Madhukar

2009-11-13

Poor methodological quality and reporting are known concerns with diagnostic accuracy studies. In 2003, the QUADAS tool and the STARD standards were published for evaluating the quality and improving the reporting of diagnostic studies, respectively. However, it is unclear whether these tools have been applied to diagnostic studies of infectious diseases. We performed a systematic review on the methodological and reporting quality of diagnostic studies in TB, malaria and HIV. We identified diagnostic accuracy studies of commercial tests for TB, malaria and HIV through a systematic search of the literature using PubMed and EMBASE (2004-2006). Original studies that reported sensitivity and specificity data were included. Two reviewers independently extracted data on study characteristics and diagnostic accuracy, and used QUADAS and STARD to evaluate the quality of methods and reporting, respectively. Ninety (38%) of 238 articles met inclusion criteria. All studies had design deficiencies. Study quality indicators that were met in less than 25% of the studies included adequate description of withdrawals (6%) and reference test execution (10%), absence of index test review bias (19%) and reference test review bias (24%), and report of uninterpretable results (22%). In terms of quality of reporting, 9 STARD indicators were reported in less than 25% of the studies: methods for calculation and estimates of reproducibility (0%), adverse effects of the diagnostic tests (1%), estimates of diagnostic accuracy between subgroups (10%), distribution of severity of disease/other diagnoses (11%), number of eligible patients who did not participate in the study (14%), blinding of the test readers (16%), and description of the team executing the test and management of indeterminate/outlier results (both 17%). The use of STARD was not explicitly mentioned in any study. Only 22% of 46 journals that published the studies included in this review required authors to use STARD. Recently published diagnostic accuracy studies on commercial tests for TB, malaria and HIV have moderate to low quality and are poorly reported. The more frequent use of tools such as QUADAS and STARD may be necessary to improve the methodological and reporting quality of future diagnostic accuracy studies in infectious diseases.

Quality and Reporting of Diagnostic Accuracy Studies in TB, HIV and Malaria: Evaluation Using QUADAS and STARD Standards

PubMed Central

Fontela, Patricia Scolari; Pant Pai, Nitika; Schiller, Ian; Dendukuri, Nandini; Ramsay, Andrew; Pai, Madhukar

2009-01-01

Background Poor methodological quality and reporting are known concerns with diagnostic accuracy studies. In 2003, the QUADAS tool and the STARD standards were published for evaluating the quality and improving the reporting of diagnostic studies, respectively. However, it is unclear whether these tools have been applied to diagnostic studies of infectious diseases. We performed a systematic review on the methodological and reporting quality of diagnostic studies in TB, malaria and HIV. Methods We identified diagnostic accuracy studies of commercial tests for TB, malaria and HIV through a systematic search of the literature using PubMed and EMBASE (2004–2006). Original studies that reported sensitivity and specificity data were included. Two reviewers independently extracted data on study characteristics and diagnostic accuracy, and used QUADAS and STARD to evaluate the quality of methods and reporting, respectively. Findings Ninety (38%) of 238 articles met inclusion criteria. All studies had design deficiencies. Study quality indicators that were met in less than 25% of the studies included adequate description of withdrawals (6%) and reference test execution (10%), absence of index test review bias (19%) and reference test review bias (24%), and report of uninterpretable results (22%). In terms of quality of reporting, 9 STARD indicators were reported in less than 25% of the studies: methods for calculation and estimates of reproducibility (0%), adverse effects of the diagnostic tests (1%), estimates of diagnostic accuracy between subgroups (10%), distribution of severity of disease/other diagnoses (11%), number of eligible patients who did not participate in the study (14%), blinding of the test readers (16%), and description of the team executing the test and management of indeterminate/outlier results (both 17%). The use of STARD was not explicitly mentioned in any study. Only 22% of 46 journals that published the studies included in this review required authors to use STARD. Conclusion Recently published diagnostic accuracy studies on commercial tests for TB, malaria and HIV have moderate to low quality and are poorly reported. The more frequent use of tools such as QUADAS and STARD may be necessary to improve the methodological and reporting quality of future diagnostic accuracy studies in infectious diseases. PMID:19915664

A portable hardware-in-the-loop (HIL) device for automotive diagnostic control systems.

PubMed

Palladino, A; Fiengo, G; Lanzo, D

2012-01-01

In-vehicle driving tests for evaluating the performance and diagnostic functionalities of engine control systems are often time consuming, expensive, and not reproducible. Using a hardware-in-the-loop (HIL) simulation approach, new control strategies and diagnostic functions on a controller area network (CAN) line can be easily tested in real time, in order to reduce the effort and the cost of the testing phase. Nowadays, spark ignition engines are controlled by an electronic control unit (ECU) with a large number of embedded sensors and actuators. In order to meet the rising demand of lower emissions and fuel consumption, an increasing number of control functions are added into such a unit. This work aims at presenting a portable electronic environment system, suited for HIL simulations, in order to test the engine control software and the diagnostic functionality on a CAN line, respectively, through non-regression and diagnostic tests. The performances of the proposed electronic device, called a micro hardware-in-the-loop system, are presented through the testing of the engine management system software of a 1.6 l Fiat gasoline engine with variable valve actuation for the ECU development version. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

The Thomson scattering diagnostic at Wendelstein 7-X and its performance in the first operation phase

NASA Astrophysics Data System (ADS)

Bozhenkov, S. A.; Beurskens, M.; Dal Molin, A.; Fuchert, G.; Pasch, E.; Stoneking, M. R.; Hirsch, M.; Höfel, U.; Knauer, J.; Svensson, J.; Trimino Mora, H.; Wolf, R. C.

2017-10-01

The optimized stellarator Wendelstein 7-X started operation in December 2015 with a 10 week limiter campaign. Divertor experiments will begin in the second half of 2017. The W7-X Thomson scattering system is an essential diagnostic for electron density and temperature profiles. In this paper the Thomson scattering diagnostic is described in detail, including its design, calibration, data evaluation and first experimental results. Plans for further development are also presented. The W7-X Thomson system is a Nd:YAG setup with up to five lasers, two sets of light collection lenses viewing the entire plasma cross-section, fiber bundles and filter based polychromators. To reduce hardware costs, two or three scattering volumes are measured with a single polychromator. The relative spectral calibration is carried out with the aid of a broadband supercontinuum light source. The absolute calibration is performed by observing Raman scattering in nitrogen. The electron temperatures and densities are recovered by Bayesian modelling. In the first campaign, the diagnostic was equipped for 10 scattering volumes. It provided temperature profiles comparable to those measured using an electron cyclotron emission diagnostic and line integrated densities within 10% of those from a dispersion interferometer.

Feasibility of UltraFast Doppler in Post-operative Evaluation of Hepatic Artery in Recipients following Liver Transplantation.

PubMed

Kim, Se-Young; Kim, Kyoung Won; Choi, Sang Hyun; Kwon, Jae Hyun; Song, Gi-Won; Kwon, Heon-Ju; Yun, Young Ju; Lee, Jeongjin; Lee, Sung-Gyu

2017-11-01

To determine the feasibility of using UltraFast Doppler in post-operative evaluation of the hepatic artery (HA) after liver transplantation (LT), we evaluated 283 simultaneous conventional and UltraFast Doppler sessions in 126 recipients over a 2-mo period after LT, using an Aixplorer scanner The Doppler indexes of the HA (peak systolic velocity [PSV], end-diastolic velocity [EDV], resistive index [RI] and systolic acceleration time [SAT]) by retrospective analysis of retrieved waves from UltraFast Doppler clips were compared with those obtained by conventional spectral Doppler. Correlation, performance in diagnosing the pathologic wave, examination time and reproducibility were evaluated. The PSV, EDV, RI and SAT of spectral and UltraFast Doppler measurements exhibited excellent correlation with favorable diagnostic performance. During the bedside examination, the mean time spent for UltraFast clip storing was significantly shorter than that for conventional Doppler US measurements. Both conventional and UltraFast Doppler exhibited good to excellent inter-analysis consistency. In conclusion, compared with conventional spectral Doppler, UltraFast Doppler values correlated excellently and yielded acceptable pathologic wave diagnostic performance with reduced examination time at the bedside and excellent reproducibility. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Diagnostic and prognostic value of human prion detection in cerebrospinal fluid.

PubMed

Foutz, Aaron; Appleby, Brian S; Hamlin, Clive; Liu, Xiaoqin; Yang, Sheng; Cohen, Yvonne; Chen, Wei; Blevins, Janis; Fausett, Cameron; Wang, Han; Gambetti, Pierluigi; Zhang, Shulin; Hughson, Andrew; Tatsuoka, Curtis; Schonberger, Lawrence B; Cohen, Mark L; Caughey, Byron; Safar, Jiri G

2017-01-01

Several prion amplification systems have been proposed for detection of prions in cerebrospinal fluid (CSF), most recently, the measurements of prion seeding activity with second-generation real-time quaking-induced conversion (RT-QuIC). The objective of this study was to investigate the diagnostic performance of the RT-QuIC prion test in the broad phenotypic spectrum of prion diseases. We performed CSF RT-QuIC testing in 2,141 patients who had rapidly progressive neurological disorders, determined diagnostic sensitivity and specificity in 272 cases that were autopsied, and evaluated the impact of mutations and polymorphisms in the PRNP gene, and type 1 or type 2 human prions on diagnostic performance. The 98.5% diagnostic specificity and 92% sensitivity of CSF RT-QuIC in a blinded retrospective analysis matched the 100% specificity and 95% sensitivity of a blind prospective study. The CSF RT-QuIC differentiated 94% of cases of sporadic Creutzfeldt-Jakob disease (sCJD) MM1 from the sCJD MM2 phenotype, and 80% of sCJD VV2 from sCJD VV1. The mixed prion type 1-2 and cases heterozygous for codon 129 generated intermediate CSF RT-QuIC patterns, whereas genetic prion diseases revealed distinct profiles for each PRNP gene mutation. The diagnostic performance of the improved CSF RT-QuIC is superior to surrogate marker tests for prion diseases such as 14-3-3 and tau proteins, and together with PRNP gene sequencing the test allows the major prion subtypes to be differentiated in vivo. This differentiation facilitates prediction of the clinicopathological phenotype and duration of the disease-two important considerations for envisioned therapeutic interventions. ANN NEUROL 2017;81:79-92. © 2016 American Neurological Association.

Diagnostic and Prognostic Value of Human Prion Detection in Cerebrospinal Fluid

PubMed Central

Foutz, Aaron; Appleby, Brian S.; Hamlin, Clive; Liu, Xiaoqin; Yang, Sheng; Cohen, Yvonne; Chen, Wei; Blevins, Janis; Fausett, Cameron; Wang, Han; Gambetti, Pierluigi; Zhang, Shulin; Hughson, Andrew; Tatsuoka, Curtis; Schonberger, Lawrence B.; Cohen, Mark L.; Caughey, Byron; Safar, Jiri G.

2016-01-01

Objective Several prion amplification systems have been proposed for detection of prions in cerebrospinal fluid (CSF), most recently, the measurements of prion seeding activity with second-generation real-time quaking-induced conversion (RT-QuIC). The objective of this study was to investigate the diagnostic performance of the RT-QuIC prion test in the broad phenotypic spectrum of prion diseases. Methods We performed CSF RT-QuIC testing in 2,141 patients who had rapidly progressive neurological disorders, determined diagnostic sensitivity and specificity in 272 cases which were autopsied, and evaluated the impact of mutations and polymorphisms in the PRNP gene, and Type 1 or Type 2 of human prions on diagnostic performance. Results The 98.5% diagnostic specificity and 92% sensitivity of CSF RT-QuIC in a blinded retrospective analysis matched the 100% specificity and 95% sensitivity of a blind prospective study. The CSF RT-QuIC differentiated 94% of cases of sporadic Creutzfeldt-Jakob disease (sCJD) MM1 from the sCJD MM2 phenotype, and 80% of sCJD VV2 from sCJD VV1. The mixed prion type 1–2 and cases heterozygous for codon 129 generated intermediate CSF RT-QuIC patterns, while genetic prion diseases revealed distinct profiles for each PRNP gene mutation. Interpretation The diagnostic performance of the improved CSF RT-QuIC is superior to surrogate marker tests for prion diseases such as 14-3-3 and Tau proteins and together with PRNP gene sequencing, the test allows the major prion subtypes to be differentiated in vivo. This differentiation facilitates prediction of the clinicopathological phenotype and duration of the disease—two important considerations for envisioned therapeutic interventions. PMID:27893164

[Peripheral lymphadenopathy in childhood--recommendations for diagnostic evaluation].

PubMed

Benesch, M; Kerbl, R; Wirnsberger, A; Stünzner, D; Mangge, H; Schenkeli, R; Deutsch, J

2000-01-01

Enlargement of peripheral lymph nodes most commonly caused by a local inflammatory process is frequently seen in childhood. The aim of the present study was to analyze the most common causes of peripheral lymphadenopathy and to develop a simple algorithm for the primary diagnostic evaluation of peripheral lymph node enlargement in this age group. Between April and September 1999 87 unselected children (median age: 5 1/2 years) with peripheral lymphadenopathy were referred to the Department of Pediatrics, University of Graz, for further investigation. EBV infection was diagnosed in 20 (23.0%) children. 19 (21.8%) patients had acute bacterial lymphadenitis. In 21 (24.1%) patients lymph node enlargement was classified as "post/parainfectious (viral)". Four patients each had toxoplasmosis and cat scratch disease. In 11 (12.6%) patients neither physical nor laboratory examinations revealed pathologic results. Among the remaining 8 children sarcoidosis and Hodgkin disease was diagnosed in one patient each. Small, soft, mobile, nontender, cervical, axillary or inguinal lymph nodes do not require further investigations. In case of enlarged, tender lymph nodes with overlying skin erythema and fever diagnostic evaluation should include complete blood count, erythrocyte sedimentation rate and/or c-reactive protein level, supplemented by appropriate antibody testing (EBV, CMV, Toxoplasma gondii, Bartonella henselae). Firm, enlarged, painless lymph nodes which are matted together and fixed to the skin or underlying tissues necessitate a more detailed diagnostic evaluation in order to exclude malignant or granulomatous diseases. Our study demonstrated that primary diagnostic evaluation of childhood peripheral lymphadenopathy is mainly based on clinical grounds. In most cases a small number of additionally performed laboratory tests allow to correctly identify the cause of the peripheral lymph node enlargement.

Utility of a point-of-care malaria rapid diagnostic test for excluding malaria as the cause of fever among HIV-positive adults in rural Rakai, Uganda.

PubMed

Mills, Lisa A; Kagaayi, Joseph; Nakigozi, Gertrude; Galiwango, Ronald M; Ouma, Joseph; Shott, Joseph P; Ssempijja, Victor; Gray, Ronald H; Wawer, Maria J; Serwadda, David; Quinn, Thomas C; Reynolds, Steven J

2010-01-01

We compared results of a malaria rapid diagnostic test (Binax Now Malaria, Binax-M, Inverness Medical Innovations, Inc., Waltham, MA) performed at rural mobile clinics in Uganda by clinicians evaluating febrile adult HIV patients to thick smear evaluated at a central laboratory by trained microscopists. Two hundred forty-six samples were analyzed, including 14 (5.7%) which were thick-smear positive for falciparum malaria. Sensitivity of Binax-M compared with thick smear was 85.7% (95% CI: 57.2-98.2), specificity 97.8% (95% CI: 94.9-99.3), positive and negative predictive values were 70.6% (95% CI: 44.0-89.7) and 99.1% (95% CI: 96.8-99.9), respectively. The rapid diagnostic test accurately ruled malaria "in or out" at the point-of-care, facilitating appropriate clinical management and averting unnecessary anti-malarial therapy.

Evaluating a Dental Diagnostic Terminology in an Electronic Health Record

PubMed Central

White, Joel M.; Kalenderian, Elsbeth; Stark, Paul C.; Ramoni, Rachel L.; Vaderhobli, Ram; Walji, Muhammad F.

2011-01-01

Standardized treatment procedure codes and terms are routinely used in dentistry. Utilization of a diagnostic terminology is common in medicine, but there is not a satisfactory or commonly standardized dental diagnostic terminology available at this time. Recent advances in dental informatics have provided an opportunity for inclusion of diagnostic codes and terms as part of treatment planning and documentation in the patient treatment history. This article reports the results of the use of a diagnostic coding system in a large dental school’s predoctoral clinical practice. A list of diagnostic codes and terms, called Z codes, was developed by dental faculty members. The diagnostic codes and terms were implemented into an electronic health record (EHR) for use in a predoctoral dental clinic. The utilization of diagnostic terms was quantified. The validity of Z code entry was evaluated by comparing the diagnostic term entered to the procedure performed, where valid diagnosis-procedure associations were determined by consensus among three calibrated academically based dentists. A total of 115,004 dental procedures were entered into the EHR during the year sampled. Of those, 43,053 were excluded from this analysis because they represent diagnosis or other procedures unrelated to treatments. Among the 71,951 treatment procedures, 27,973 had diagnoses assigned to them with an overall utilization of 38.9 percent. Of the 147 available Z codes, ninety-three were used (63.3 percent). There were 335 unique procedures provided and 2,127 procedure/diagnosis pairs captured in the EHR. Overall, 76.7 percent of the diagnoses entered were valid. We conclude that dental diagnostic terminology can be incorporated within an electronic health record and utilized in an academic clinical environment. Challenges remain in the development of terms and implementation and ease of use that, if resolved, would improve the utilization. PMID:21546594

Evaluation of the udder health status in subclinical mastitis affected dairy cows through bacteriological culture, somatic cell count and thermographic imaging.

PubMed

Bortolami, A; Fiore, E; Gianesella, M; Corrò, M; Catania, S; Morgante, M

2015-01-01

Subclinical mastitis in dairy cows is a big economic loss for farmers. The monitoring of subclinical mastitis is usually performed through Somatic Cell Count (SCC) in farm but there is the need of new diagnostic systems able to quickly identify cows affected by subclinical infections of the udder. The aim of this study was to evaluate the potential application of thermographic imaging compared to SCC and bacteriological culture for infection detection in cow affected by subclinical mastitis and possibly to discriminate between different pathogens. In this study we evaluated the udder health status of 98 Holstein Friesian dairy cows with high SCC in 4 farms. From each cow a sample of milk was collected from all the functional quarters and submitted to bacteriological culture, SCC and Mycoplasma spp. culture. A thermographic image was taken from each functional udder quarter and nipple. Pearson's correlations and Analysis of Variance were performed in order to evaluate the different diagnostic techniques. The most frequent pathogen isolated was Staphylococcus aureus followed by Coagulase Negative Staphylococci (CNS), Streptococcus uberis, Streptococcus agalactiae and others. The Somatic Cell Score (SCS) was able to discriminate (p<0.05) cows positive for a pathogen from cows negative at the bacteriological culture except for cows with infection caused by CNS. Infrared thermography was correlated to SCS (p<0.05) but was not able to discriminate between positive and negative cows. Thermographic imaging seems to be promising in evaluating the inflammation status of cows affected by subclinical mastitis but seems to have a poor diagnostic value.

Diagnostic validity of physical examination tests for common knee disorders: An overview of systematic reviews and meta-analysis.

PubMed

Décary, Simon; Ouellet, Philippe; Vendittoli, Pascal-André; Roy, Jean-Sébastien; Desmeules, François

2017-01-01

More evidence on diagnostic validity of physical examination tests for knee disorders is needed to lower frequently used and costly imaging tests. To conduct a systematic review of systematic reviews (SR) and meta-analyses (MA) evaluating the diagnostic validity of physical examination tests for knee disorders. A structured literature search was conducted in five databases until January 2016. Methodological quality was assessed using the AMSTAR. Seventeen reviews were included with mean AMSTAR score of 5.5 ± 2.3. Based on six SR, only the Lachman test for ACL injuries is diagnostically valid when individually performed (Likelihood ratio (LR+):10.2, LR-:0.2). Based on two SR, the Ottawa Knee Rule is a valid screening tool for knee fractures (LR-:0.05). Based on one SR, the EULAR criteria had a post-test probability of 99% for the diagnosis of knee osteoarthritis. Based on two SR, a complete physical examination performed by a trained health provider was found to be diagnostically valid for ACL, PCL and meniscal injuries as well as for cartilage lesions. When individually performed, common physical tests are rarely able to rule in or rule out a specific knee disorder, except the Lachman for ACL injuries. There is low-quality evidence concerning the validity of combining history elements and physical tests. Copyright © 2016 Elsevier Ltd. All rights reserved.

Exploration of Analysis Methods for Diagnostic Imaging Tests: Problems with ROC AUC and Confidence Scores in CT Colonography

PubMed Central

Mallett, Susan; Halligan, Steve; Collins, Gary S.; Altman, Doug G.

2014-01-01

Background Different methods of evaluating diagnostic performance when comparing diagnostic tests may lead to different results. We compared two such approaches, sensitivity and specificity with area under the Receiver Operating Characteristic Curve (ROC AUC) for the evaluation of CT colonography for the detection of polyps, either with or without computer assisted detection. Methods In a multireader multicase study of 10 readers and 107 cases we compared sensitivity and specificity, using radiological reporting of the presence or absence of polyps, to ROC AUC calculated from confidence scores concerning the presence of polyps. Both methods were assessed against a reference standard. Here we focus on five readers, selected to illustrate issues in design and analysis. We compared diagnostic measures within readers, showing that differences in results are due to statistical methods. Results Reader performance varied widely depending on whether sensitivity and specificity or ROC AUC was used. There were problems using confidence scores; in assigning scores to all cases; in use of zero scores when no polyps were identified; the bimodal non-normal distribution of scores; fitting ROC curves due to extrapolation beyond the study data; and the undue influence of a few false positive results. Variation due to use of different ROC methods exceeded differences between test results for ROC AUC. Conclusions The confidence scores recorded in our study violated many assumptions of ROC AUC methods, rendering these methods inappropriate. The problems we identified will apply to other detection studies using confidence scores. We found sensitivity and specificity were a more reliable and clinically appropriate method to compare diagnostic tests. PMID:25353643

Exploration of analysis methods for diagnostic imaging tests: problems with ROC AUC and confidence scores in CT colonography.

PubMed

Mallett, Susan; Halligan, Steve; Collins, Gary S; Altman, Doug G

2014-01-01

Different methods of evaluating diagnostic performance when comparing diagnostic tests may lead to different results. We compared two such approaches, sensitivity and specificity with area under the Receiver Operating Characteristic Curve (ROC AUC) for the evaluation of CT colonography for the detection of polyps, either with or without computer assisted detection. In a multireader multicase study of 10 readers and 107 cases we compared sensitivity and specificity, using radiological reporting of the presence or absence of polyps, to ROC AUC calculated from confidence scores concerning the presence of polyps. Both methods were assessed against a reference standard. Here we focus on five readers, selected to illustrate issues in design and analysis. We compared diagnostic measures within readers, showing that differences in results are due to statistical methods. Reader performance varied widely depending on whether sensitivity and specificity or ROC AUC was used. There were problems using confidence scores; in assigning scores to all cases; in use of zero scores when no polyps were identified; the bimodal non-normal distribution of scores; fitting ROC curves due to extrapolation beyond the study data; and the undue influence of a few false positive results. Variation due to use of different ROC methods exceeded differences between test results for ROC AUC. The confidence scores recorded in our study violated many assumptions of ROC AUC methods, rendering these methods inappropriate. The problems we identified will apply to other detection studies using confidence scores. We found sensitivity and specificity were a more reliable and clinically appropriate method to compare diagnostic tests.

Diagnostic Accuracy and Cost-Effectiveness of Alternative Methods for Detection of Soil-Transmitted Helminths in a Post-Treatment Setting in Western Kenya

PubMed Central

Kepha, Stella; Kihara, Jimmy H.; Njenga, Sammy M.; Pullan, Rachel L.; Brooker, Simon J.

2014-01-01

Objectives This study evaluates the diagnostic accuracy and cost-effectiveness of the Kato-Katz and Mini-FLOTAC methods for detection of soil-transmitted helminths (STH) in a post-treatment setting in western Kenya. A cost analysis also explores the cost implications of collecting samples during school surveys when compared to household surveys. Methods Stool samples were collected from children (n = 652) attending 18 schools in Bungoma County and diagnosed by the Kato-Katz and Mini-FLOTAC coprological methods. Sensitivity and additional diagnostic performance measures were analyzed using Bayesian latent class modeling. Financial and economic costs were calculated for all survey and diagnostic activities, and cost per child tested, cost per case detected and cost per STH infection correctly classified were estimated. A sensitivity analysis was conducted to assess the impact of various survey parameters on cost estimates. Results Both diagnostic methods exhibited comparable sensitivity for detection of any STH species over single and consecutive day sampling: 52.0% for single day Kato-Katz; 49.1% for single-day Mini-FLOTAC; 76.9% for consecutive day Kato-Katz; and 74.1% for consecutive day Mini-FLOTAC. Diagnostic performance did not differ significantly between methods for the different STH species. Use of Kato-Katz with school-based sampling was the lowest cost scenario for cost per child tested ($10.14) and cost per case correctly classified ($12.84). Cost per case detected was lowest for Kato-Katz used in community-based sampling ($128.24). Sensitivity analysis revealed the cost of case detection for any STH decreased non-linearly as prevalence rates increased and was influenced by the number of samples collected. Conclusions The Kato-Katz method was comparable in diagnostic sensitivity to the Mini-FLOTAC method, but afforded greater cost-effectiveness. Future work is required to evaluate the cost-effectiveness of STH surveillance in different settings. PMID:24810593

Diagnostic accuracy and cost-effectiveness of alternative methods for detection of soil-transmitted helminths in a post-treatment setting in western Kenya.

PubMed

Assefa, Liya M; Crellen, Thomas; Kepha, Stella; Kihara, Jimmy H; Njenga, Sammy M; Pullan, Rachel L; Brooker, Simon J

2014-05-01

This study evaluates the diagnostic accuracy and cost-effectiveness of the Kato-Katz and Mini-FLOTAC methods for detection of soil-transmitted helminths (STH) in a post-treatment setting in western Kenya. A cost analysis also explores the cost implications of collecting samples during school surveys when compared to household surveys. Stool samples were collected from children (n = 652) attending 18 schools in Bungoma County and diagnosed by the Kato-Katz and Mini-FLOTAC coprological methods. Sensitivity and additional diagnostic performance measures were analyzed using Bayesian latent class modeling. Financial and economic costs were calculated for all survey and diagnostic activities, and cost per child tested, cost per case detected and cost per STH infection correctly classified were estimated. A sensitivity analysis was conducted to assess the impact of various survey parameters on cost estimates. Both diagnostic methods exhibited comparable sensitivity for detection of any STH species over single and consecutive day sampling: 52.0% for single day Kato-Katz; 49.1% for single-day Mini-FLOTAC; 76.9% for consecutive day Kato-Katz; and 74.1% for consecutive day Mini-FLOTAC. Diagnostic performance did not differ significantly between methods for the different STH species. Use of Kato-Katz with school-based sampling was the lowest cost scenario for cost per child tested ($10.14) and cost per case correctly classified ($12.84). Cost per case detected was lowest for Kato-Katz used in community-based sampling ($128.24). Sensitivity analysis revealed the cost of case detection for any STH decreased non-linearly as prevalence rates increased and was influenced by the number of samples collected. The Kato-Katz method was comparable in diagnostic sensitivity to the Mini-FLOTAC method, but afforded greater cost-effectiveness. Future work is required to evaluate the cost-effectiveness of STH surveillance in different settings.

CMAQ Application to the Southern Oxidant and Aerosol Study (SOAS)

EPA Pesticide Factsheets

CMAQ was used to simulate conditions during the the Southern Oxidant and Aerosol Study (SOAS) in the summer of 2013. Data collected as part of this study have been used to perform diagnostic model evaluation.

Diagnostic Assessment of Deep Learning Algorithms for Detection of Lymph Node Metastases in Women With Breast Cancer

PubMed Central

Veta, Mitko; Johannes van Diest, Paul; van Ginneken, Bram; Karssemeijer, Nico; Litjens, Geert; van der Laak, Jeroen A. W. M.; Hermsen, Meyke; Manson, Quirine F; Balkenhol, Maschenka; Geessink, Oscar; Stathonikos, Nikolaos; van Dijk, Marcory CRF; Bult, Peter; Beca, Francisco; Beck, Andrew H; Wang, Dayong; Khosla, Aditya; Gargeya, Rishab; Irshad, Humayun; Zhong, Aoxiao; Dou, Qi; Li, Quanzheng; Chen, Hao; Lin, Huang-Jing; Heng, Pheng-Ann; Haß, Christian; Bruni, Elia; Wong, Quincy; Halici, Ugur; Öner, Mustafa Ümit; Cetin-Atalay, Rengul; Berseth, Matt; Khvatkov, Vitali; Vylegzhanin, Alexei; Kraus, Oren; Shaban, Muhammad; Rajpoot, Nasir; Awan, Ruqayya; Sirinukunwattana, Korsuk; Qaiser, Talha; Tsang, Yee-Wah; Tellez, David; Annuscheit, Jonas; Hufnagl, Peter; Valkonen, Mira; Kartasalo, Kimmo; Latonen, Leena; Ruusuvuori, Pekka; Liimatainen, Kaisa; Albarqouni, Shadi; Mungal, Bharti; George, Ami; Demirci, Stefanie; Navab, Nassir; Watanabe, Seiryo; Seno, Shigeto; Takenaka, Yoichi; Matsuda, Hideo; Ahmady Phoulady, Hady; Kovalev, Vassili; Kalinovsky, Alexander; Liauchuk, Vitali; Bueno, Gloria; Fernandez-Carrobles, M. Milagro; Serrano, Ismael; Deniz, Oscar; Racoceanu, Daniel; Venâncio, Rui

2017-01-01

Importance Application of deep learning algorithms to whole-slide pathology images can potentially improve diagnostic accuracy and efficiency. Objective Assess the performance of automated deep learning algorithms at detecting metastases in hematoxylin and eosin–stained tissue sections of lymph nodes of women with breast cancer and compare it with pathologists’ diagnoses in a diagnostic setting. Design, Setting, and Participants Researcher challenge competition (CAMELYON16) to develop automated solutions for detecting lymph node metastases (November 2015-November 2016). A training data set of whole-slide images from 2 centers in the Netherlands with (n = 110) and without (n = 160) nodal metastases verified by immunohistochemical staining were provided to challenge participants to build algorithms. Algorithm performance was evaluated in an independent test set of 129 whole-slide images (49 with and 80 without metastases). The same test set of corresponding glass slides was also evaluated by a panel of 11 pathologists with time constraint (WTC) from the Netherlands to ascertain likelihood of nodal metastases for each slide in a flexible 2-hour session, simulating routine pathology workflow, and by 1 pathologist without time constraint (WOTC). Exposures Deep learning algorithms submitted as part of a challenge competition or pathologist interpretation. Main Outcomes and Measures The presence of specific metastatic foci and the absence vs presence of lymph node metastasis in a slide or image using receiver operating characteristic curve analysis. The 11 pathologists participating in the simulation exercise rated their diagnostic confidence as definitely normal, probably normal, equivocal, probably tumor, or definitely tumor. Results The area under the receiver operating characteristic curve (AUC) for the algorithms ranged from 0.556 to 0.994. The top-performing algorithm achieved a lesion-level, true-positive fraction comparable with that of the pathologist WOTC (72.4% [95% CI, 64.3%-80.4%]) at a mean of 0.0125 false-positives per normal whole-slide image. For the whole-slide image classification task, the best algorithm (AUC, 0.994 [95% CI, 0.983-0.999]) performed significantly better than the pathologists WTC in a diagnostic simulation (mean AUC, 0.810 [range, 0.738-0.884]; P < .001). The top 5 algorithms had a mean AUC that was comparable with the pathologist interpreting the slides in the absence of time constraints (mean AUC, 0.960 [range, 0.923-0.994] for the top 5 algorithms vs 0.966 [95% CI, 0.927-0.998] for the pathologist WOTC). Conclusions and Relevance In the setting of a challenge competition, some deep learning algorithms achieved better diagnostic performance than a panel of 11 pathologists participating in a simulation exercise designed to mimic routine pathology workflow; algorithm performance was comparable with an expert pathologist interpreting whole-slide images without time constraints. Whether this approach has clinical utility will require evaluation in a clinical setting. PMID:29234806

An adaptive toolkit for image quality evaluation in system performance test of digital breast tomosynthesis

NASA Astrophysics Data System (ADS)

Zhang, Guozhi; Petrov, Dimitar; Marshall, Nicholas; Bosmans, Hilde

2017-03-01

Digital breast tomosynthesis (DBT) is a relatively new diagnostic imaging modality for women. Currently, various models of DBT systems are available on the market and the number of installations is rapidly increasing. EUREF, the European Reference Organization for Quality Assured Breast Screening and Diagnostic Services, has proposed a preliminary Guideline - protocol for the quality control of the physical and technical aspects of digital breast tomosynthesis systems, with an ultimate aim of providing limiting values guaranteeing proper performance for different applications of DBT. In this work, we introduce an adaptive toolkit developed in accordance with this guideline to facilitate the process of image quality evaluation in DBT performance test. This toolkit implements robust algorithms to quantify various technical parameters of DBT images and provides a convenient user interface in practice. Each test is built into a separate module with configurations set corresponding to the European guideline, which can be easily adapted to different settings and extended with additional tests. This toolkit largely improves the efficiency for image quality evaluation of DBT. It is also going to evolve with the development of protocols in quality control of DBT systems.

Assessment of Literature Related to Combustion Appliance Venting Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rapp, V. H.; Less, B. D.; Singer, B. C.

In many residential building retrofit programs, air tightening to increase energy efficiency is often constrained by safety concerns with naturally vented combustion appliances. Tighter residential buildings more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spill combustion exhaust into the living space. Several measures, such as installation guidelines, vent sizing codes, and combustion safety diagnostics, are in place with the intent to prevent backdrafting and combustion spillage, but the diagnostics conflict and the risk mitigation objective is inconsistent. This literature review summarizes the metrics and diagnostics used to assess combustion safety, documents theirmore » technical basis, and investigates their risk mitigations. It compiles information from the following: codes for combustion appliance venting and installation; standards and guidelines for combustion safety diagnostics; research evaluating combustion safety diagnostics; research investigating wind effects on building depressurization and venting; and software for simulating vent system performance.« less

"Combined Diagnostic Tool" APPlication to a Retrospective Series of Patients Undergoing Total Joint Revision Surgery.

PubMed

Gallazzi, Enrico; Drago, Lorenzo; Baldini, Andrea; Stockley, Ian; George, David A; Scarponi, Sara; Romanò, Carlo L

2017-01-01

Background : Differentiating between septic and aseptic joint prosthesis may be challenging, since no single test is able to confirm or rule out infection. The choice and interpretation of the panel of tests performed in any case often relies on empirical evaluation and poorly validated scores. The "Combined Diagnostic Tool (CDT)" App, a smartphone application for iOS, was developed to allow to automatically calculate the probability of having a of periprosthetic joint infection, on the basis of the relative sensitivity and specificity of the positive and negative diagnostic tests performed in any given patient. Objective : The aim of the present study was to apply the CDT software to investigate the ability of the tests routinely performed in three high-volume European centers to diagnose a periprosthetic infection. Methods : This three-center retrospective study included 120 consecutive patients undergoing total hip or knee revision, and included 65 infected patients (Group A) and 55 patients without infection (Group B). The following parameters were evaluated: number and type of positive and negative diagnostic tests performed pre-, intra- and post-operatively and resultant probability calculated by the CDT App of having a peri-prosthetic joint infection, based on pre-, intra- and post-operative combined tests. Results : Serological tests were the most common performed, with an average 2.7 tests per patient for Group A and 2.2 for Group B, followed by joint aspiration (0.9 and 0.8 tests per patient, respectively) and imaging techniques (0.5 and 0.2 test per patient). Mean CDT App calculated probability of having an infection based on pre-operative tests was 79.4% for patients in Group A and 35.7 in Group B. Twenty-nine patients in Group A had > 10% chance of not having an infection, and 29 of Group B had > 10% chance of having an infection. Conclusion : This is the first retrospective study focused on investigating the number and type of tests commonly performed prior to joint revision surgery and aimed at evaluating their combined ability to diagnose a peri-prosthetic infection. CDT App allowed us to demonstrate that, on average, the routine combination of commonly used tests is unable to diagnose pre-operatively a peri-prosthetic infection with a probability higher than 90%.

Diagnostic, therapeutic and economic consequences of a positive urinary antigen test for Legionella spp. in patients admitted with community-acquired pneumonia: a 7-year retrospective evaluation.

PubMed

Engel, M F; van Manen, L; Hoepelman, A I M; Thijsen, S; Oosterheert, J J

2013-09-01

A positive urinary antigen test for Legionella spp. (Legionella urinary antigen test; LUAT) allows an early switch from empiric to targeted treatment (TT) in hospitalised, community-acquired pneumonia (CAP) patients. We aimed to evaluate the diagnostic, therapeutic and economic consequences of this frequently used test 7 years after its implementation. We retrospectively evaluated LUATs performed between 2005 and 2011 in two teaching hospitals. All tests performed in hospitalised CAP patients were used in the economic evaluation and positive tests were included in the treatment evaluation. Data on patient characteristics, admission and outcome were retrieved from the patients' files. The number of days gained by making a rapid aetiological diagnosis, the number of days TT could be provided and their costs were calculated. Of 4485 LUATs, 2504 (56%) were performed for CAP including 55 (1%) positive tests (€1041/positive test). In 26 (60%) of the 43 included positive tests, LUAT was the only test showing Legionella spp. Subsequently, earlier TT was possible in the remaining cases during 209 cumulative admission days (€274/TT day). LUAT led to detection of Legionella spp. 13 days earlier per case (€203/day) as compared with culture/serology alone. Timely LUAT use in accordance with current guidelines allows early detection and treatment of CAP caused by Legionella spp. at considerable expense.

Diagnostic methods for assessing maxillary skeletal and dental transverse deficiencies: A systematic review

PubMed Central

Sawchuk, Dena; Currie, Kris; Vich, Manuel Lagravere; Palomo, Juan Martin

2016-01-01

Objective To evaluate the accuracy and reliability of the diagnostic tools available for assessing maxillary transverse deficiencies. Methods An electronic search of three databases was performed from their date of establishment to April 2015, with manual searching of reference lists of relevant articles. Articles were considered for inclusion if they reported the accuracy or reliability of a diagnostic method or evaluation technique for maxillary transverse dimensions in mixed or permanent dentitions. Risk of bias was assessed in the included articles, using the Quality Assessment of Diagnostic Accuracy Studies tool-2. Results Nine articles were selected. The studies were heterogeneous, with moderate to low methodological quality, and all had a high risk of bias. Four suggested that the use of arch width prediction indices with dental cast measurements is unreliable for use in diagnosis. Frontal cephalograms derived from cone-beam computed tomography (CBCT) images were reportedly more reliable for assessing intermaxillary transverse discrepancies than posteroanterior cephalograms. Two studies proposed new three-dimensional transverse analyses with CBCT images that were reportedly reliable, but have not been validated for clinical sensitivity or specificity. No studies reported sensitivity, specificity, positive or negative predictive values or likelihood ratios, or ROC curves of the methods for the diagnosis of transverse deficiencies. Conclusions Current evidence does not enable solid conclusions to be drawn, owing to a lack of reliable high quality diagnostic studies evaluating maxillary transverse deficiencies. CBCT images are reportedly more reliable for diagnosis, but further validation is required to confirm CBCT's accuracy and diagnostic superiority. PMID:27668196

Does probability guided hysteroscopy reduce costs in women investigated for postmenopausal bleeding?

PubMed

Breijer, M C; van Hanegem, N; Visser, N C M; Verheijen, R H M; Mol, B W J; Pijnenborg, J M A; Opmeer, B C; Timmermans, A

2015-01-01

To evaluate whether a model to predict a failed endometrial biopsy in women with postmenopausal bleeding (PMB) and a thickened endometrium can reduce costs without compromising diagnostic accuracy. Model based cost-minimization analysis. A decision analytic model was designed to compare two diagnostic strategies for women with PMB: (I) attempting office endometrial biopsy and performing outpatient hysteroscopy after failed biopsy and (II) predicted probability of a failed endometrial biopsy based on patient characteristics to guide the decision for endometrial biopsy or immediate hysteroscopy. Robustness of assumptions regarding costs was evaluated in sensitivity analyses. Costs for the different strategies. At different cut-offs for the predicted probability of failure of an endometrial biopsy, strategy I was generally less expensive than strategy II. The costs for strategy I were always € 460; the costs for strategy II varied between € 457 and € 475. At a 65% cut-off, a possible saving of € 3 per woman could be achieved. Individualizing the decision to perform an endometrial biopsy or immediate hysteroscopy in women presenting with postmenopausal bleeding based on patient characteristics does not increase the efficiency of the diagnostic work-up.

Tapered Roller Bearing Damage Detection Using Decision Fusion Analysis

NASA Technical Reports Server (NTRS)

Dempsey, Paula J.; Kreider, Gary; Fichter, Thomas

2006-01-01

A diagnostic tool was developed for detecting fatigue damage of tapered roller bearings. Tapered roller bearings are used in helicopter transmissions and have potential for use in high bypass advanced gas turbine aircraft engines. A diagnostic tool was developed and evaluated experimentally by collecting oil debris data from failure progression tests conducted using health monitoring hardware. Failure progression tests were performed with tapered roller bearings under simulated engine load conditions. Tests were performed on one healthy bearing and three pre-damaged bearings. During each test, data from an on-line, in-line, inductance type oil debris sensor and three accelerometers were monitored and recorded for the occurrence of bearing failure. The bearing was removed and inspected periodically for damage progression throughout testing. Using data fusion techniques, two different monitoring technologies, oil debris analysis and vibration, were integrated into a health monitoring system for detecting bearing surface fatigue pitting damage. The data fusion diagnostic tool was evaluated during bearing failure progression tests under simulated engine load conditions. This integrated system showed improved detection of fatigue damage and health assessment of the tapered roller bearings as compared to using individual health monitoring technologies.

Performance analysis of automated evaluation of Crithidia luciliae-based indirect immunofluorescence tests in a routine setting - strengths and weaknesses.

PubMed

Hormann, Wymke; Hahn, Melanie; Gerlach, Stefan; Hochstrate, Nicola; Affeldt, Kai; Giesen, Joyce; Fechner, Kai; Damoiseaux, Jan G M C

2017-11-27

Antibodies directed against dsDNA are a highly specific diagnostic marker for the presence of systemic lupus erythematosus and of particular importance in its diagnosis. To assess anti-dsDNA antibodies, the Crithidia luciliae-based indirect immunofluorescence test (CLIFT) is one of the assays considered to be the best choice. To overcome the drawback of subjective result interpretation that inheres indirect immunofluorescence assays in general, automated systems have been introduced into the market during the last years. Among these systems is the EUROPattern Suite, an advanced automated fluorescence microscope equipped with different software packages, capable of automated pattern interpretation and result suggestion for ANA, ANCA and CLIFT analysis. We analyzed the performance of the EUROPattern Suite with its automated fluorescence interpretation for CLIFT in a routine setting, reflecting the everyday life of a diagnostic laboratory. Three hundred and twelve consecutive samples were collected, sent to the Central Diagnostic Laboratory of the Maastricht University Medical Centre with a request for anti-dsDNA analysis over a period of 7 months. Agreement between EUROPattern assay analysis and the visual read was 93.3%. Sensitivity and specificity were 94.1% and 93.2%, respectively. The EUROPattern Suite performed reliably and greatly supported result interpretation. Automated image acquisition is readily performed and automated image classification gives a reliable recommendation for assay evaluation to the operator. The EUROPattern Suite optimizes workflow and contributes to standardization between different operators or laboratories.

[Evaluation (assessment) of three tests for diagnosis of geohelmints in Colombia].

PubMed

López, Myriam Consuelo; Moncada, Ligia Inés; Ariza-Araújo, Yoseth; Fernández-Niño, Julián Alfredo; Reyes, Patricia; Nicholls, Rubén Santiago

2013-01-01

Soil-transmitted helminth infections are considered a public health problem in developing countries. The diagnostic tests, both for individual parient diagnosis as for population studies should be evaluated in terms of validity and reliability. To compare the direct examination, the modified Ritchie-Frick method, a Kato-Katz designed by a Brazilian group and one designed by the WHO, for the diagnosis of soil-transmitted helminthes. A diagnostic test reliability study was performed. The same stool sample was analyzed by the same observer using four diagnostic tests. 204 samples were obtained, 194 of those fulfilled the inclusion criteria and were analyzed. The observers did not know the participants' identity neither the other tests results. For the analysis the Kato-Katz (WHO) was considered as the gold standard. For the reliability assessment percent agreement, positive percent agreement, Kappa statistic, and intraclass correlation were performed. The Brazilian Kato-Katz showed a good performance with high sensitivity and specificity for T. trichiura and Hookworm with values of 0.97 and 0.96 respectively, and a high specificity with mild sensitivity for A. lumbricoides (0.95 and 0.79) meanwhile the direct examination and the Ritche-Frick method showed a performance between mild and poor. The differences were higher for hookworm and Trichiuris trichiura than for Ascaris lumbricoides. The Brazilian Kato Katz test could be implemented, but further studies are needed to correlate its operative capacity with its feasibility, availability and cost.

Endoscopic Ultrasound for the Hepatologist: A Comprehensive Review.

PubMed

Rimbaş, Mihai; Di Maurizio, Luca; Rizzatti, Gianenrico; Gasbarrini, Antonio; Costamagna, Guido; Larghi, Alberto

2018-05-01

In the last few years, the diagnostic and therapeutic utilization of endoscopic ultrasound (EUS) for a variety of liver conditions has exponentially grown. We performed a thorough search for all available studies on the performance of diagnostic and therapeutic EUS in the field of hepatology. This article reviews the indication of EUS in the evaluation and treatment of portal hypertension, portal vein pressure measurement, focal liver lesions, and parenchymal liver diseases, and presents all the clinical evidences available so far in this regard. All the review data suggest that EUS is becoming an increasingly important tool in the armamentarium of the hepatologists for the management of certain liver-related conditions. Implementation in the education of the hepatologists of means to become more familiar with both diagnostic and therapeutic capabilities of EUS is warranted. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Preclinical study of diagnostic performances of contrast-enhanced spectral mammography versus MRI for breast diseases in China.

PubMed

Wang, Qingguo; Li, Kangan; Wang, Lihui; Zhang, Jianbing; Zhou, Zhiguo; Feng, Yan

2016-01-01

To evaluate diagnostic performances of CESM for breast diseases with comparison to breast MRI in China. Sixty-eight patients with 77 breast lesions underwent MR and CESM. Two radiologists interpreted either MRI or CESM images, separately and independently. BI-RADS 1-3 and BI-RADS 4-5 were classified into the suspicious benign and suspicious malignant groups. Diagnostic accuracy parameters were calculated. Receiver operating characteristic (ROC) curves were constructed for the two modalities. The agreement and correlation between maximum lesion diameter based on CESM and MRI, or CESM and pathology were analyzed. Diagnostic accuracy parameters for CESM were sensitivity 95.8 %, specificity 65.5 %, PPV 82.1 %, NPV 90.5 % and accuracy 84.4 %. The diagnostic accuracy parameters for breast MRI were sensitivity 93.8 %, specificity 82.8 %, PPV 88.2 %, NPV 92.3 %and accuracy 89.6 %. Area under the curve (AUC) of ROC was 0.96 for breast MRI and 0.88 for CESM. The Bland-Altman plots showed a mean difference of 0.7 mm with 95 % limits of agreement of 11.4 mm in tumor diameter measured using CESM and breast MRI. The differences of size measurement between CESM and breast MRI were significant, whereas no difference was observed between CESM and pathology as well as between breast MRI and pathology. The better correlation with pathological results was found in CESM than breast MRI. Our study demonstrates that CESM possesses better diagnostic performances than breast MRI in terms of diagnostic sensitivity and lesion size assessment. And CESM is a good alternative method of screening breast cancer in high-risk people.

Head-camera video recordings of trauma core competency procedures can evaluate surgical resident's technical performance as well as colocated evaluators.

PubMed

Mackenzie, Colin F; Pasley, Jason; Garofalo, Evan; Shackelford, Stacy; Chen, Hegang; Longinaker, Nyaradzo; Granite, Guinevere; Pugh, Kristy; Hagegeorge, George; Tisherman, Samuel A

2017-07-01

Unbiased evaluation of trauma core competency procedures is necessary to determine if residency and predeployment training courses are useful. We tested whether a previously validated individual procedure score (IPS) for individual procedure vascular exposure and fasciotomy (FAS) performance skills could discriminate training status by comparing IPS of evaluators colocated with surgeons to blind video evaluations. Performance of axillary artery (AA), brachial artery (BA), and femoral artery (FA) vascular exposures and lower extremity FAS on fresh cadavers by 40 PGY-2 to PGY-6 residents was video-recorded from head-mounted cameras. Two colocated trained evaluators assessed IPS before and after training. One surgeon in each pretraining tertile of IPS for each procedure was randomly identified for blind video review. The same 12 surgeons were video-recorded repeating the procedures less than 4 weeks after training. Five evaluators independently reviewed all 96 randomly arranged deidentified videos. Inter-rater reliability/consistency, intraclass correlation coefficients were compared by colocated versus video review of IPS, and errors. Study methodology and bias were judged by Medical Education Research Study Quality Instrument and the Quality Assessment of Diagnostic Accuracy Studies criteria. There were no differences (p ≥ 0.5) in IPS for AA, FA, FAS, whether evaluators were colocated or reviewed video recordings. Evaluator consistency was 0.29 (BA) - 0.77 (FA). Video and colocated evaluators were in total agreement (p = 1.0) for error recognition. Intraclass correlation coefficient was 0.73 to 0.92, dependent on procedure. Correlations video versus colocated evaluations were 0.5 to 0.9. Except for BA, blinded video evaluators discriminated (p < 0.002) whether procedures were performed before training versus after training. Study methodology by Medical Education Research Study Quality Instrument criteria scored 15.5/19, Quality Assessment of Diagnostic Accuracy Studies 2 showed low bias risk. Video evaluations of AA, FA, and FAS procedures with IPS are unbiased, valid, and have potential for formative assessments of competency. Prognostic study, level II.

Systematic Review and Meta-Analysis of Studies Evaluating Diagnostic Test Accuracy: A Practical Review for Clinical Researchers-Part II. Statistical Methods of Meta-Analysis

PubMed Central

Lee, Juneyoung; Kim, Kyung Won; Choi, Sang Hyun; Huh, Jimi

2015-01-01

Meta-analysis of diagnostic test accuracy studies differs from the usual meta-analysis of therapeutic/interventional studies in that, it is required to simultaneously analyze a pair of two outcome measures such as sensitivity and specificity, instead of a single outcome. Since sensitivity and specificity are generally inversely correlated and could be affected by a threshold effect, more sophisticated statistical methods are required for the meta-analysis of diagnostic test accuracy. Hierarchical models including the bivariate model and the hierarchical summary receiver operating characteristic model are increasingly being accepted as standard methods for meta-analysis of diagnostic test accuracy studies. We provide a conceptual review of statistical methods currently used and recommended for meta-analysis of diagnostic test accuracy studies. This article could serve as a methodological reference for those who perform systematic review and meta-analysis of diagnostic test accuracy studies. PMID:26576107

Whole Exome Sequencing in Pediatric Neurology Patients: Clinical Implications and Estimated Cost Analysis.

PubMed

Nolan, Danielle; Carlson, Martha

2016-06-01

Genetic heterogeneity in neurologic disorders has been an obstacle to phenotype-based diagnostic testing. The authors hypothesized that information compiled via whole exome sequencing will improve clinical diagnosis and management of pediatric neurology patients. The authors performed a retrospective chart review of patients evaluated in the University of Michigan Pediatric Neurology clinic between 6/2011 and 6/2015. The authors recorded previous diagnostic testing, indications for whole exome sequencing, and whole exome sequencing results. Whole exome sequencing was recommended for 135 patients and obtained in 53 patients. Insurance barriers often precluded whole exome sequencing. The most common indication for whole exome sequencing was neurodevelopmental disorders. Whole exome sequencing improved the presumptive diagnostic rate in the patient cohort from 25% to 48%. Clinical implications included family planning, medication selection, and systemic investigation. Compared to current second tier testing, whole exome sequencing can result in lower long-term charges and more timely diagnosis. Overcoming barriers related to whole exome sequencing insurance authorization could allow for more efficient and fruitful diagnostic neurological evaluations. © The Author(s) 2016.

Multicenter evaluation of molecular and culture-dependent diagnostics for Shigella species and Entero-invasive Escherichia coli in the Netherlands.

PubMed

van den Beld, Maaike J C; Friedrich, Alexander W; van Zanten, Evert; Reubsaet, Frans A G; Kooistra-Smid, Mirjam A M D; Rossen, John W A

2016-12-01

An inter-laboratory collaborative trial for the evaluation of diagnostics for detection and identification of Shigella species and Entero-invasive Escherichia coli (EIEC) was performed. Sixteen Medical Microbiological Laboratories (MMLs) participated. MMLs were interviewed about their diagnostic methods and a sample panel, consisting of DNA-extracts and spiked stool samples with different concentrations of Shigella flexneri, was provided to each MML. The results of the trial showed an enormous variety in culture-dependent and molecular diagnostic techniques currently used among MMLs. Despite the various molecular procedures, 15 out of 16 MMLs were able to detect Shigella species or EIEC in all the samples provided, showing that the diversity of methods has no effect on the qualitative detection of Shigella flexneri. In contrast to semi quantitative analysis, the minimum and maximum values per sample differed by approximately five threshold cycles (Ct-value) between the MMLs included in the study. This indicates that defining a uniform Ct-value cut-off for notification to health authorities is not advisable. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparison of strain and acoustic radiation force impulse elastography of breast lesions by qualitative evaluation.

PubMed

Zhao, Qing; Wang, Xiao-Lei; Sun, Jia-Wei; Jiang, Zhao-Peng; Tao, Lin; Zhou, Xian-Li

2018-04-13

To compare the diagnostic performance of conventional strain elastography (CSE) and acoustic radiation force impulse (ARFI) induced SE for qualitative assessment of breast lesions and evaluate the additional value of the two techniques combined with Breast Imaging Reporting and Data System (BI-RADS) respectively for the differentiation of benign and malignant breast lesions. In a cohort of 110 women, the conventional ultrasound (US) features and the elasticity scores of CSE and ARFI induced SE were recorded. The diagnostic performances of BI-RADS, elastography and BI-RADS plus elastography were evaluated, including the area under the receiver operating characteristic curve (AUROC), sensitivity, specificity and accuracy. Pathologically, there were forty-eight malignant and sixty-two benign breast lesions in the final analysis. The AUCs for CSE and ARFI induced SE are similar (CSE, 0.807; ARFI induced SE, 0.846; p > 0.05), however, the specificity of the latter method was significantly higher than that of CSE (83.9% vs. 58.1%, p = 0.004) in differentiating breast lesions. The accuracy and specificity of BI-RADS plus ARFI induced SE (84.5%, 80.6%, respectively) were significantly higher than BI-RADS alone (73.6%, 54.8%, respectively) and BI-RADS plus conventional SE (72.7%, 56.5%, respectively), respectively (p < 0.05) without loss of sensitivity. Our study showed that BI-RADS plus ARFI induced SE had a better diagnostic performance in the diagnosis of breast lesions in comparison with BI-RADS alone or BI-RADS plus CSE.

Evaluation of Multiplexed Foot-and-Mouth Disease Nonstructural Protein Antibody Assay Against Standardized Bovine Serum Panel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perkins, J; Parida, S; Clavijo, A

2007-05-14

Liquid array technology has previously been used to show proof-of-principle of a multiplexed non structural protein serological assay to differentiate foot-and-mouth infected and vaccinated animals. The current multiplexed assay consists of synthetically produced peptide signatures 3A, 3B and 3D and recombinant protein signature 3ABC in combination with four controls. To determine diagnostic specificity of each signature in the multiplex, the assay was evaluated against a naive population (n = 104) and a vaccinated population (n = 94). Subsequently, the multiplexed assay was assessed using a panel of bovine sera generated by the World Reference Laboratory for foot-and-mouth disease in Pirbright,more » UK. This sera panel has been used to assess the performance of other singleplex ELISA-based non-structural protein antibody assays. The 3ABC signature in the multiplexed assay showed comparative performance to a commercially available non-structural protein 3ABC ELISA (Cedi test{reg_sign}) and additional information pertaining to the relative diagnostic sensitivity of each signature in the multiplex is acquired in one experiment. The encouraging results of the evaluation of the multiplexed assay against a panel of diagnostically relevant samples promotes further assay development and optimization to generate an assay for routine use in foot-and-mouth disease surveillance.« less

Malaria rapid diagnostic test in children: The Zamfara, Nigeria experience.

PubMed

Abdulkadir, Isa; Rufai, Hafsah Ahmad; Ochapa, Sunday Onazi; Malam, Mado Sani; Garba, Bilkisu Ilah; Oloko, Adebayo Ganiyu Yusuf; George, Idemudia Itoya

2015-01-01

Malaria remains a major cause of under-five morbidity and mortality in Nigeria, and prompt diagnosis occupies a strategic position in its management. Malaria rapid diagnostic test (RDT), a nontechnical, easy to perform test promises to meet this need. It is important to locally document the usefulness of the use of RDT in making prompt malaria diagnosis in children. To determine the prevalence of malaria and evaluate the diagnostic performance of malaria RDT kit in febrile under-five children presenting to a Tertiary Health Facility in Gusau, North-Western Nigeria. A cross-sectional study of children aged 6-59 months, evaluated for malaria in a tertiary health facility from August 2012 to January 2013. Information was obtained from care providers of all subjects with fever and a presumptive diagnosis of malaria. All subjects were investigated using Giemsa stain microscopy and Carestart™ malaria RDT. The prevalence of malaria in 250 febrile under-five children was 54%. Three-quarter (79%) of the children received inappropriate nonrecommended antimalaria prior to their presentation, including 20% who received chloroquine. The overall sensitivity of RDT was 40.3%. The specificity, positive and negative predictive values were 89.6%, 81.8%, and 56.5%, respectively. Use of RDT should be encouraged for screening and diagnosis using a protocol such that febrile children with positive RDT results are confirmed as having malaria while those with negative results are further evaluated using microscopy.

Comparison and Combination of Strain and Shear Wave Elastography of Breast Masses for Differentiation of Benign and Malignant Lesions by Quantitative Assessment: Preliminary Study.

PubMed

Seo, Mirinae; Ahn, Hye Shin; Park, Sung Hee; Lee, Jong Beum; Choi, Byung Ihn; Sohn, Yu-Mee; Shin, So Youn

2018-01-01

To compare the diagnostic performance of strain and shear wave elastography of breast masses for quantitative assessment in differentiating benign and malignant lesions and to evaluate the diagnostic accuracy of combined strain and shear wave elastography. Between January and February 2016, 37 women with 45 breast masses underwent both strain and shear wave ultrasound (US) elastographic examinations. The American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) final assessment on B-mode US imaging was assessed. We calculated strain ratios for strain elastography and the mean elasticity value and elasticity ratio of the lesion to fat for shear wave elastography. Diagnostic performances were compared by using the area under the receiver operating characteristic curve (AUC). The 37 women had a mean age of 47.4 years (range, 20-79 years). Of the 45 lesions, 20 were malignant, and 25 were benign. The AUCs for elasticity values on strain and shear wave elastography showed no significant differences (strain ratio, 0.929; mean elasticity, 0.898; and elasticity ratio, 0.868; P > .05). After selectively downgrading BI-RADS category 4a lesions based on strain and shear wave elastographic cutoffs, the AUCs for the combined sets of B-mode US and elastography were improved (B-mode + strain, 0.940; B-mode + shear wave; 0.964; and B-mode, 0.724; P < .001). Combined strain and shear wave elastography showed significantly higher diagnostic accuracy than each individual elastographic modality (P = .031). These preliminary results showed that strain and shear wave elastography had similar diagnostic performance. The addition of strain and shear wave elastography to B-mode US improved diagnostic performance. The combination of strain and shear wave elastography results in a higher diagnostic yield than each individual elastographic modality. © 2017 by the American Institute of Ultrasound in Medicine.

Effect of Radiologists’ Diagnostic Work-up Volume on Interpretive Performance

PubMed Central

Anderson, Melissa L.; Smith, Robert A.; Carney, Patricia A.; Miglioretti, Diana L.; Monsees, Barbara S.; Sickles, Edward A.; Taplin, Stephen H.; Geller, Berta M.; Yankaskas, Bonnie C.; Onega, Tracy L.

2014-01-01

Purpose To examine radiologists’ screening performance in relation to the number of diagnostic work-ups performed after abnormal findings are discovered at screening mammography by the same radiologist or by different radiologists. Materials and Methods In an institutional review board–approved HIPAA-compliant study, the authors linked 651 671 screening mammograms interpreted from 2002 to 2006 by 96 radiologists in the Breast Cancer Surveillance Consortium to cancer registries (standard of reference) to evaluate the performance of screening mammography (sensitivity, false-positive rate [FPRfalse-positive rate], and cancer detection rate [CDRcancer detection rate]). Logistic regression was used to assess the association between the volume of recalled screening mammograms (“own” mammograms, where the radiologist who interpreted the diagnostic image was the same radiologist who had interpreted the screening image, and “any” mammograms, where the radiologist who interpreted the diagnostic image may or may not have been the radiologist who interpreted the screening image) and screening performance and whether the association between total annual volume and performance differed according to the volume of diagnostic work-up. Results Annually, 38% of radiologists performed the diagnostic work-up for 25 or fewer of their own recalled screening mammograms, 24% performed the work-up for 0–50, and 39% performed the work-up for more than 50. For the work-up of recalled screening mammograms from any radiologist, 24% of radiologists performed the work-up for 0–50 mammograms, 32% performed the work-up for 51–125, and 44% performed the work-up for more than 125. With increasing numbers of radiologist work-ups for their own recalled mammograms, the sensitivity (P = .039), FPRfalse-positive rate (P = .004), and CDRcancer detection rate (P < .001) of screening mammography increased, yielding a stepped increase in women recalled per cancer detected from 17.4 for 25 or fewer mammograms to 24.6 for more than 50 mammograms. Increases in work-ups for any radiologist yielded significant increases in FPRfalse-positive rate (P = .011) and CDRcancer detection rate (P = .001) and a nonsignificant increase in sensitivity (P = .15). Radiologists with a lower annual volume of any work-ups had consistently lower FPRfalse-positive rate, sensitivity, and CDRcancer detection rate at all annual interpretive volumes. Conclusion These findings support the hypothesis that radiologists may improve their screening performance by performing the diagnostic work-up for their own recalled screening mammograms and directly receiving feedback afforded by means of the outcomes associated with their initial decision to recall. Arranging for radiologists to work up a minimum number of their own recalled cases could improve screening performance but would need systems to facilitate this workflow. © RSNA, 2014 Online supplemental material is available for this article. PMID:24960110

Effect of radiologists' diagnostic work-up volume on interpretive performance.

PubMed

Buist, Diana S M; Anderson, Melissa L; Smith, Robert A; Carney, Patricia A; Miglioretti, Diana L; Monsees, Barbara S; Sickles, Edward A; Taplin, Stephen H; Geller, Berta M; Yankaskas, Bonnie C; Onega, Tracy L

2014-11-01

To examine radiologists' screening performance in relation to the number of diagnostic work-ups performed after abnormal findings are discovered at screening mammography by the same radiologist or by different radiologists. In an institutional review board-approved HIPAA-compliant study, the authors linked 651 671 screening mammograms interpreted from 2002 to 2006 by 96 radiologists in the Breast Cancer Surveillance Consortium to cancer registries (standard of reference) to evaluate the performance of screening mammography (sensitivity, false-positive rate [ FPR false-positive rate ], and cancer detection rate [ CDR cancer detection rate ]). Logistic regression was used to assess the association between the volume of recalled screening mammograms ("own" mammograms, where the radiologist who interpreted the diagnostic image was the same radiologist who had interpreted the screening image, and "any" mammograms, where the radiologist who interpreted the diagnostic image may or may not have been the radiologist who interpreted the screening image) and screening performance and whether the association between total annual volume and performance differed according to the volume of diagnostic work-up. Annually, 38% of radiologists performed the diagnostic work-up for 25 or fewer of their own recalled screening mammograms, 24% performed the work-up for 0-50, and 39% performed the work-up for more than 50. For the work-up of recalled screening mammograms from any radiologist, 24% of radiologists performed the work-up for 0-50 mammograms, 32% performed the work-up for 51-125, and 44% performed the work-up for more than 125. With increasing numbers of radiologist work-ups for their own recalled mammograms, the sensitivity (P = .039), FPR false-positive rate (P = .004), and CDR cancer detection rate (P < .001) of screening mammography increased, yielding a stepped increase in women recalled per cancer detected from 17.4 for 25 or fewer mammograms to 24.6 for more than 50 mammograms. Increases in work-ups for any radiologist yielded significant increases in FPR false-positive rate (P = .011) and CDR cancer detection rate (P = .001) and a nonsignificant increase in sensitivity (P = .15). Radiologists with a lower annual volume of any work-ups had consistently lower FPR false-positive rate , sensitivity, and CDR cancer detection rate at all annual interpretive volumes. These findings support the hypothesis that radiologists may improve their screening performance by performing the diagnostic work-up for their own recalled screening mammograms and directly receiving feedback afforded by means of the outcomes associated with their initial decision to recall. Arranging for radiologists to work up a minimum number of their own recalled cases could improve screening performance but would need systems to facilitate this workflow.

Strategies for adding adaptive learning mechanisms to rule-based diagnostic expert systems

NASA Technical Reports Server (NTRS)

Stclair, D. C.; Sabharwal, C. L.; Bond, W. E.; Hacke, Keith

1988-01-01

Rule-based diagnostic expert systems can be used to perform many of the diagnostic chores necessary in today's complex space systems. These expert systems typically take a set of symptoms as input and produce diagnostic advice as output. The primary objective of such expert systems is to provide accurate and comprehensive advice which can be used to help return the space system in question to nominal operation. The development and maintenance of diagnostic expert systems is time and labor intensive since the services of both knowledge engineer(s) and domain expert(s) are required. The use of adaptive learning mechanisms to increment evaluate and refine rules promises to reduce both time and labor costs associated with such systems. This paper describes the basic adaptive learning mechanisms of strengthening, weakening, generalization, discrimination, and discovery. Next basic strategies are discussed for adding these learning mechanisms to rule-based diagnostic expert systems. These strategies support the incremental evaluation and refinement of rules in the knowledge base by comparing the set of advice given by the expert system (A) with the correct diagnosis (C). Techniques are described for selecting those rules in the in the knowledge base which should participate in adaptive learning. The strategies presented may be used with a wide variety of learning algorithms. Further, these strategies are applicable to a large number of rule-based diagnostic expert systems. They may be used to provide either immediate or deferred updating of the knowledge base.

Evaluation of an Intelligent Tutoring System in Pathology: Effects of External Representation on Performance Gains, Metacognition, and Acceptance

PubMed Central

Crowley, Rebecca S.; Legowski, Elizabeth; Medvedeva, Olga; Tseytlin, Eugene; Roh, Ellen; Jukic, Drazen

2007-01-01

Objective Determine effects of computer-based tutoring on diagnostic performance gains, meta-cognition, and acceptance using two different problem representations. Describe impact of tutoring on spectrum of diagnostic skills required for task performance. Identify key features of student-tutor interaction contributing to learning gains. Design Prospective, between-subjects study, controlled for participant level of training. Resident physicians in two academic pathology programs spent four hours using one of two interfaces which differed mainly in external problem representation. The case-focused representation provided an open-learning environment in which students were free to explore evidence-hypothesis relationships within a case, but could not visualize the entire diagnostic space. The knowledge-focused representation provided an interactive representation of the entire diagnostic space, which more tightly constrained student actions. Measurements Metrics included results of pretest, post-test and retention-test for multiple choice and case diagnosis tests, ratios of performance to student reported certainty, results of participant survey, learning curves, and interaction behaviors during tutoring. Results Students had highly significant learning gains after one tutoring session. Learning was retained at one week. There were no differences between the two interfaces in learning gains on post-test or retention test. Only students in the knowledge-focused interface exhibited significant metacognitive gains from pretest to post-test and pretest to retention test. Students rated the knowledge-focused interface significantly higher than the case-focused interface. Conclusions Cognitive tutoring is associated with improved diagnostic performance in a complex medical domain. The effect is retained at one-week post-training. Knowledge-focused external problem representation shows an advantage over case-focused representation for metacognitive effects and user acceptance. PMID:17213494

Evaluation of an intelligent tutoring system in pathology: effects of external representation on performance gains, metacognition, and acceptance.

PubMed

Crowley, Rebecca S; Legowski, Elizabeth; Medvedeva, Olga; Tseytlin, Eugene; Roh, Ellen; Jukic, Drazen

2007-01-01

Determine effects of computer-based tutoring on diagnostic performance gains, meta-cognition, and acceptance using two different problem representations. Describe impact of tutoring on spectrum of diagnostic skills required for task performance. Identify key features of student-tutor interaction contributing to learning gains. Prospective, between-subjects study, controlled for participant level of training. Resident physicians in two academic pathology programs spent four hours using one of two interfaces which differed mainly in external problem representation. The case-focused representation provided an open-learning environment in which students were free to explore evidence-hypothesis relationships within a case, but could not visualize the entire diagnostic space. The knowledge-focused representation provided an interactive representation of the entire diagnostic space, which more tightly constrained student actions. Metrics included results of pretest, post-test and retention-test for multiple choice and case diagnosis tests, ratios of performance to student reported certainty, results of participant survey, learning curves, and interaction behaviors during tutoring. Students had highly significant learning gains after one tutoring session. Learning was retained at one week. There were no differences between the two interfaces in learning gains on post-test or retention test. Only students in the knowledge-focused interface exhibited significant metacognitive gains from pretest to post-test and pretest to retention test. Students rated the knowledge-focused interface significantly higher than the case-focused interface. Cognitive tutoring is associated with improved diagnostic performance in a complex medical domain. The effect is retained at one-week post-training. Knowledge-focused external problem representation shows an advantage over case-focused representation for metacognitive effects and user acceptance.

A comparison of FibroMeter™ NAFLD Score, NAFLD fibrosis score, and transient elastography as noninvasive diagnostic tools for hepatic fibrosis in patients with biopsy-proven non-alcoholic fatty liver disease.

PubMed

Aykut, Umut Emre; Akyuz, Umit; Yesil, Atakan; Eren, Fatih; Gerin, Fatma; Ergelen, Rabia; Celikel, Cigdem Ataizi; Yilmaz, Yusuf

2014-11-01

Noninvasive markers that purport to distinguish patients with non-alcoholic fatty liver disease (NAFLD) with fibrosis from those without must be evaluated rigorously for their classification accuracy. Herein, we seek to compare the diagnostic performances of three different noninvasive methods (FibroMeter™ NAFLD score, NAFLD Fibrosis score (NFSA), and Transient Elastrography [TE]) for the detection of liver fibrosis in NAFLD patients. A total of 88 patients with biopsy-proven NAFLD were included. The Kleiner system was used for grading fibrosis in liver biopsies. The FibroMeter™ NAFLD score was determined using a proprietary algorithm (regression score). The NFSA score was calculated based on age, hyperglycemia, body mass index, platelets, albumin and serum aminotransferase levels. TE was performed using the Fibroscan apparatus. The sensitivities/specificities for the FibroMeter™ NAFLD score, NFSA, and TE for the diagnosis of significant fibrosis (F2 + F3 + F4 fibrosis) were 38.6%/86.4%, 52.3%/88.6%, and 75.0%/93.2%, respectively. The areas under the receiver operating characteristic curves of TE were significantly higher than those of both the FibroMeter™ NAFLD score and NFSA. No significant differences were found between the FibroMeter™ NAFLD score and NFSA for the detection of significant and severe fibrosis, although the diagnostic performance of the FibroMeter™ NAFLD score was higher than that of the NFSA score for cirrhosis. In summary, TE showed the best diagnostic performance for the noninvasive assessment of liver fibrosis in NAFLD patients. The diagnostic performances of the FibroMeter™ NAFLD score and NFSA did not differ significantly for the detection of both significant and severe fibrosis.

Measuring outcome differences associated with STEMI screening and diagnostic performance: a multicentred retrospective cohort study protocol.

PubMed

Yiadom, Maame Yaa A B; Mumma, Bryn E; Baugh, Christopher W; Patterson, Brian W; Mills, Angela M; Salazar, Gilberto; Tanski, Mary; Jenkins, Cathy A; Vogus, Timothy J; Miller, Karen F; Jackson, Brittney E; Lehmann, Christoph U; Dorner, Stephen C; West, Jennifer L; Wang, Thomas J; Collins, Sean P; Dittus, Robert S; Bernard, Gordon R; Storrow, Alan B; Liu, Dandan

2018-05-03

Advances in ST-segment elevation myocardial infarction (STEMI) management have involved improving the clinical processes connecting patients with timely emergency cardiovascular care. Screening upon emergency department (ED) arrival for an early ECG to diagnose STEMI, however, is not optimal for all patients. In addition, the degree to which timely screening and diagnosis are associated with improved time to intervention and postpercutaneous coronary intervention outcomes, under more contemporary practice conditions, is not known. We present the methods for a retrospective multicentre cohort study anticipated to include 1220 patients across seven EDs to (1) evaluate the relationship between timely screening and diagnosis with treatment and postintervention clinical outcomes; (2) introduce novel measures for cross-facility performance comparisons of screening and diagnostic care team performance including: door-to-screening, door-to-diagnosis and door-to-catheterisation laboratory arrival times and (3) describe the use of electronic health record data in tandem with an existing disease registry. The completion of this study will provide critical feedback on the quality of screening and diagnostic performance within the contemporary STEMI care pathway that can be used to (1) improve emergency care delivery for patients with STEMI presenting to the ED, (2) present novel metrics for the comparison of screening and diagnostic care and (3) inform the development of screening and diagnostic support tools that could be translated to other care environments. We will disseminate our results via publication and quality performance data sharing with each site. Institutional ethics review approval was received prior to study initiation. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Liver fibrosis staging with a new 2D-shear wave elastography using comb-push technique: Applicability, reproducibility, and diagnostic performance

PubMed Central

Lee, Sang Min; Kang, Hyo-Jin; Yang, Hyung Kung; Yoon, Jeong Hee; Chang, Won; An, Su Joa; Lee, Kyoung Bun; Baek, Seung Yon

2017-01-01

Objective To evaluate the applicability, reproducibility, and diagnostic performance of a new 2D-shear wave elastography (SWE) using the comb-push technique (2D CP-SWE) for detection of hepatic fibrosis, using histopathology as the reference standard. Materials and methods This prospective study was approved by the institutional review board, and informed consent was obtained from all patients. The liver stiffness (LS) measurements were obtained from 140 patients, using the new 2D-SWE, which uses comb-push excitation to produce shear waves and a time-aligned sequential tracking method to detect shear wave signals. The applicability rate of 2D CP-SWE was estimated, and factors associated with its applicability were identified. Intraobserver reproducibility was evaluated in the 105 patients with histopathologic diagnosis, and interobserver reproducibility was assessed in 20 patients. Diagnostic performance of the 2D CP-SWE for hepatic fibrosis was evaluated by receiver operating characteristic (ROC) curve analysis. Results The applicability rate of 2D CP-SWE was 90.8% (109 of 120). There was a significant difference in age, presence or absence of ascites, and the distance from the transducer to the Glisson capsule between the patients with applicable LS measurements and patients with unreliable measurement or technical failure. The intraclass correlation of interobserver agreement was 0.87, and the value for the intraobserver agreement was 0.95. The area under the ROC curve of LS values for stage F2 fibrosis or greater, stage F3 or greater, and stage F4 fibrosis was 0.874 (95% confidence interval [CI]: 0.794–0.930), 0.905 (95% CI: 0.832–0.954), and 0.894 (95% CI: 0.819–0.946), respectively. Conclusion 2D CP-SWE can be employed as a reliable method for assessing hepatic fibrosis with a reasonably good diagnostic performance, and its applicability might be influenced by age, ascites, and the distance between the transducer and Glisson capsule. PMID:28510583

[Diagnostics and treatment decisions in acute compartment syndrome. Results of a survey in German hospitals].

PubMed

Sellei, R M; Andruszkow, H; Weber, C; Damen, T O; Pape, H-C; Hildebrand, F

2016-02-01

The presented survey was intended to evaluate whether a standardization of diagnostics and therapy for acute compartment syndrome has been achieved. University hospitals, academic teaching hospitals, and county hospitals in Germany were included. A total of 38% (n=120) of all contacted hospitals participated in this study with questions mainly answered by consulting physicians (68%). In general the importance of the clinical examination was considered as being more important than other diagnostic measures. In cases where further diagnostics were necessary, the intramuscular pressure measurement was used most frequently. Of the participants 50% performed surgical fasciotomy based on the clinical examination in combination with the intramuscular pressure measurement; however, there were considerable differences between the participating hospitals with respect to the anatomical position of intramuscular measurements, the limiting value of the intramuscular pressure and the surgical technique for performing fasciotomy. According to the presented analysis the diagnosis and indications for surgical treatment in patients developing an acute compartment syndrome do not seem to be sufficiently clarified. The establishment of unified treatment guidelines could help to reduce the number of delayed diagnoses of compartment syndrome.

Diagnostic Imaging of Reproductive Tract Disorders in Reptiles.

PubMed

Gumpenberger, Michaela

2017-05-01

Diagnostic imaging of the reproductive tract in reptiles is used for gender determination, evaluation of breeding status, detection of pathologic changes, and supervising treatment. Whole-body radiographs provide an overview and support detection of mineralized egg shells. Sonography is used to evaluate follicles, nonmineralized eggs, and the salpinx in all reptiles. Computed tomography is able to overcome imaging limitations in chelonian species. This article provides detailed information about the performance of different imaging techniques. Multiple images demonstrate the physiologic appearance of the male and female reproductive tract in various reptile species and pathologic changes. Advantages and disadvantages of radiography, sonography, and computed tomography are described. Copyright © 2016 Elsevier Inc. All rights reserved.

Breast-specific gamma camera imaging with 99mTc-MIBI has better diagnostic performance than magnetic resonance imaging in breast cancer patients: A meta-analysis.

PubMed

Zhang, Aimi; Li, Panli; Liu, Qiufang; Song, Shaoli

2017-01-01

This study aimed to evaluate the diagnostic role of breast-specific gamma camera imaging (BSGI) with technetium-99m-methoxy isobutyl isonitrile ( 99m Tc-MIBI) and magnetic resonance imaging (MRI) in patients with breast cancer through a meta-analysis. Three reviewers searched articles published in medical journals before June 2016 in MEDLINE, EMBASE and Springer Databases; the references listed in original articles were also retrieved. We used the quality assessment of diagnostic accuracy studies (QUADAS) tool to assess the quality of the included studies. Heterogeneity, pooled sensitivity and specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio (DOR) and summary receiver operating characteristic (SROC) curves were calculated by Meta-DiSc software to estimate the diagnostic performance of BSGI and MRI. Ten studies with 517 patients were included after meeting the inclusion criteria. We did a subgroup analysis of the same data type. The pooled sensitivities of BSGI and MRI were: 0.84 (95% CI, 0.79-0.88) and 0.89 (95% CI, 0.84-0.92) respectively, and the pooled specificities of BSGI and MRI were: 0.82 (95% CI, 0.74-0.88) and 0.39 (95% CI, 0.30-0.49) respectively. The areas under the SROC curve of BSGI and MRI were 0.93 and 0.72 respectively. The results of our meta-analysis indicated that compared with MRI, BSGI has similar sensitivity, higher specificity, better diagnostic performance, and can be widely used in clinical practice.

Diagnostic Performance of (18)F-Fluorodeoxyglucose in 162 Small Pulmonary Nodules Incidentally Detected in Subjects Without a History of Malignancy.

PubMed

Calcagni, Maria Lucia; Taralli, Silvia; Cardillo, Giuseppe; Graziano, Paolo; Ialongo, Pasquale; Mattoli, Maria Vittoria; Di Franco, Davide; Caldarella, Carmelo; Carleo, Francesco; Indovina, Luca; Giordano, Alessandro

2016-04-01

Solitary pulmonary nodule (SPN) still represents a diagnostic challenge. The aim of our study was to evaluate the diagnostic performance of (18)F-fluorodeoxyglucose positron emission tomography-computed tomography in one of the largest samples of small SPNs, incidentally detected in subjects without a history of malignancy (nonscreening population) and undetermined at computed tomography. One-hundred and sixty-two small (>0.8 to 1.5 cm) and, for comparison, 206 large nodules (>1.5 to 3 cm) were retrospectively evaluated. Diagnostic performance of (18)F-fluorodeoxyglucose visual analysis, receiver-operating characteristic (ROC) analysis for maximum standardized uptake value (SUVmax), and Bayesian analysis were assessed using histology or radiological follow-up as a golden standard. In 162 small nodules, (18)F-fluorodeoxyglucose visual and ROC analyses (SUVmax = 1.3) provided 72.6% and 77.4% sensitivity and 88.0% and 82.0% specificity, respectively. The prevalence of malignancy was 38%; Bayesian analysis provided 78.8% positive and 16.0% negative posttest probabilities of malignancy. In 206 large nodules (18)F-fluorodeoxyglucose visual and ROC analyses (SUVmax = 1.9) provided 89.5% and 85.1% sensitivity and 70.8% and 79.2% specificity, respectively. The prevalence of malignancy was 65%; Bayesian analysis provided 85.0% positive and 21.6% negative posttest probabilities of malignancy. In both groups, malignant nodules had a significant higher SUVmax (p < 0.0001) than benign nodules. Only in the small group, malignant nodules were significantly larger (p = 0.0054) than benign ones. (18)F-fluorodeoxyglucose can be clinically relevant to rule in and rule out malignancy in undetermined small SPNs, incidentally detected in nonscreening population with intermediate pretest probability of malignancy, as well as in larger ones. Visual analysis can be considered an optimal diagnostic criterion, adequately detecting a wide range of malignant nodules with different metabolic activity. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Use of the Filovirus Animal Non-Clinical Group (FANG) Ebola virus immuno-assay requires fewer study participants to power a study than the Alpha Diagnostic International assay.

PubMed

Logue, James; Tuznik, Kaylie; Follmann, Dean; Grandits, Greg; Marchand, Jonathan; Reilly, Cavan; Sarro, Yeya Dit Sadio; Pettitt, James; Stavale, Eric J; Fallah, Mosoka; Olinger, Gene G; Bolay, Fatorma K; Hensley, Lisa E

2018-05-01

As part of the scientific community's development of medical countermeasures against Ebola virus disease, optimization of standardized assays for product evaluation is paramount. The recent outbreak heightened awareness to the scarcity of available assays and limited information on performance and reproducibility. To evaluate the immunogenicity of vaccines entering Phase I-III trials and to identify survivors, two enzyme-linked immunosorbent assays, the Filovirus Animal Non-Clinical Group assay and the Alpha Diagnostics International assay, were evaluated for detection of immunoglobulin G against Ebola virus glycoprotein. We found that the Filovirus Animal Nonclinical Group assay produced a wider range of relative antibody concentrations, higher assay precision, larger relative accuracy range, and lower regional background. Additionally, to sufficiently power a vaccine trial, use of the Filovirus Animal Nonclinical Group assay would require one third the number of participants than the Alpha Diagnostics International assay. This reduction in needed study participants will require less money, fewer man hours, and much less time to evaluate vaccine immunogenicity. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Diagnostic Performance of Bronchoalveolar Lavage Fluid CD4/CD8 Ratio for Sarcoidosis: A Meta-analysis.

PubMed

Shen, Yongchun; Pang, Caishuang; Wu, Yanqiu; Li, Diandian; Wan, Chun; Liao, Zenglin; Yang, Ting; Chen, Lei; Wen, Fuqiang

2016-06-01

The usefulness of bronchoalveolar lavage fluid (BALF) CD4/CD8 ratio for diagnosing sarcoidosis has been reported in many studies with variable results. Therefore, we performed a meta-analysis to estimate the overall diagnostic accuracy of BALF CD4/CD8 ratio based on the bulk of published evidence. Studies published prior to June 2015 and indexed in PubMed, OVID, Web of Science, Scopus and other databases were evaluated for inclusion. Data on sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were pooled from included studies. Summary receiver operating characteristic (SROC) curves were used to summarize overall test performance. Deeks's funnel plot was used to detect publication bias. Sixteen publications with 1885 subjects met our inclusion criteria and were included in this meta-analysis. Summary estimates of the diagnostic performance of the BALF CD4/CD8 ratio were as follows: sensitivity, 0.70 (95%CI 0.64-0.75); specificity, 0.83 (95%CI 0.78-0.86); PLR, 4.04 (95%CI 3.13-5.20); NLR, 0.36 (95%CI 0.30-0.44); and DOR, 11.17 (95%CI 7.31-17.07). The area under the SROC curve was 0.84 (95%CI 0.81-0.87). There was no evidence of publication bias. Measuring the BALF CD4/CD8 ratio may assist in the diagnosis of sarcoidosis when interpreted in parallel with other diagnostic factors. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Evaluation of the methodological quality of studies of the performance of diagnostic tests for bovine tuberculosis using QUADAS.

PubMed

Downs, Sara H; More, Simon J; Goodchild, Anthony V; Whelan, Adam O; Abernethy, Darrell A; Broughan, Jennifer M; Cameron, Angus; Cook, Alasdair J; Ricardo de la Rua-Domenech, R; Greiner, Matthias; Gunn, Jane; Nuñez-Garcia, Javier; Rhodes, Shelley; Rolfe, Simon; Sharp, Michael; Upton, Paul; Watson, Eamon; Welsh, Michael; Woolliams, John A; Clifton-Hadley, Richard S; Parry, Jessica E

2018-05-01

There has been little assessment of the methodological quality of studies measuring the performance (sensitivity and/or specificity) of diagnostic tests for animal diseases. In a systematic review, 190 studies of tests for bovine tuberculosis (bTB) in cattle (published 1934-2009) were assessed by at least one of 18 reviewers using the QUADAS (Quality Assessment of Diagnostic Accuracy Studies) checklist adapted for animal disease tests. VETQUADAS (VQ) included items measuring clarity in reporting (n = 3), internal validity (n = 9) and external validity (n = 2). A similar pattern for compliance was observed in studies of different diagnostic test types. Compliance significantly improved with year of publication for all items measuring clarity in reporting and external validity but only improved in four of the nine items measuring internal validity (p < 0.05). 107 references, of which 83 had performance data eligible for inclusion in a meta-analysis were reviewed by two reviewers. In these references, agreement between reviewers' responses was 71% for compliance, 32% for unsure and 29% for non-compliance. Mean compliance with reporting items was 2, 5.2 for internal validity and 1.5 for external validity. The index test result was described in sufficient detail in 80.1% of studies and was interpreted without knowledge of the reference standard test result in only 33.1%. Loss to follow-up was adequately explained in only 31.1% of studies. The prevalence of deficiencies observed may be due to inadequate reporting but may also reflect lack of attention to methodological issues that could bias the results of diagnostic test performance estimates. QUADAS was a useful tool for assessing and comparing the quality of studies measuring the performance of diagnostic tests but might be improved further by including explicit assessment of population sampling strategy. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Potential diagnostic performance of contrast-enhanced ultrasound and tumor markers in differentiating combined hepatocellular-cholangiocarcinoma from hepatocellular carcinoma and cholangiocarcinoma.

PubMed

Huang, Xiao-Wen; Huang, Yang; Chen, Li-da; Wang, Zhu; Yang, Zheng; Liu, Jin-Ya; Xie, Xiao-Yan; Lu, Ming-De; Shen, Shun-Li; Wang, Wei

2018-04-01

To evaluate the diagnostic performance of the combination of tumor markers [alpha-fetoprotein (AFP) and carbohydrate antigen 19-9 (CA19-9)] and imaging features in differentiating combined hepatocellular-cholangiocarcinoma (CHC) from hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC). Forty consecutive patients with pathologically proven CHC were retrospectively evaluated with contrast-enhanced ultrasound (CEUS). Additionally, 40 HCC and 40 CC patients who were randomly selected from the same period served as a control group. Images were classified as HCC-like or CC-like pattern according to CEUS guidelines recommended by World and European Federation for Ultrasound in Medicine and Biology (WFUMB-EFSUMB). The diagnostic criteria of CHC were defined as follows: (1) both AFP and CA19-9 are simultaneously elevated (AFP > 20 ng/ml and CA19-9 > 100 units/ml); or (2) elevated AFP with a CC-like pattern on CEUS and without elevated CA19-9 level; or (3) elevated CA19-9 with an HCC-like pattern on CEUS and without elevated AFP level. The diagnostic tests were performed with calculation of the sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic curve (AUC). For the 40 CHC patients, the rates of elevated AFP and CA19-9 serology were 55.0 and 30.0%, respectively. Twenty-three (57.5%) patients exhibited an HCC-like pattern, and 15 (37.5%) showed a CC-like pattern. After applying the above diagnostic criteria of CHC in the 120 patients, the sensitivity, specificity, PPV, NPV, accuracy, and AUC were 32.5, 93.8, 72.2, 73.5, 73.3, and 0.631%, respectively. When the actual prevalence rate (0.4-14.3%) was taken into account, the PPV and NPV were modified from 2.1 to 46.7% and 89.3 to 99.7%, respectively. The combination of enhancement patterns on CEUS and serum tumor markers (AFP and CA19-9) may be a potentially specific diagnostic method to differentiate CHC from HCC and CC.

Early Migration Predicts Aseptic Loosening of Cementless Femoral Stems: A Long-term Study.

PubMed

Streit, Marcus R; Haeussler, Daniel; Bruckner, Thomas; Proctor, Tanja; Innmann, Moritz M; Merle, Christian; Gotterbarm, Tobias; Weiss, Stefan

2016-07-01

Excessive early migration of cemented stems and cups after THA has been associated with poor long-term survival and allows predictable evaluation of implant performance. However, there are few data regarding the relationship between early migration and aseptic loosening of cementless femoral components, and whether early migration might predict late failure has not been evaluated, to our knowledge. Einzel-Bild-Röntgen-Analyse-femoral component analysis (EBRA-FCA) is a validated technique to accurately measure axial femoral stem migration without the need for tantalum markers, can be performed retrospectively, and may be a suitable tool to identify poor performing implants before their widespread use. We asked: (1) Is axial migration within the first 24 months as assessed by EBRA-FCA greater among cementless stems that develop aseptic loosening than those that remain well fixed through the second decade; (2) what is the diagnostic performance of implant migration at 24 months postoperatively to predict later aseptic loosening of these components; and (3) how does long-term stem survivorship compare between groups with high and low early migration? We evaluated early axial stem migration in 158 cementless THAs using EBRA-FCA. The EBRA-FCA measurements were performed during the first week postoperatively (baseline measurement) and at regular followups of 3, 6, and 12 months postoperatively and annually thereafter. The mean duration of followup was 21 years (range, 18-24 years). The stems studied represented 45% (158 of 354) of the cementless THAs performed during that time, and cementless THAs represented 34% (354 of 1038) of the THA practice during that period. No patient enrolled in this study was lost to followup. Multivariate survivorship analysis using Cox's regression model was performed with an endpoint of aseptic loosening of the femoral component. Loosening was defined according to the criteria described by Engh et al. and assessed by two independent observers. Patients with a diagnosis of prosthetic joint infection were excluded. Receiver operating characteristic (ROC) curve analysis was used to evaluate diagnostic performance of axial stem migration 1, 2, 3, and 4 years postoperatively as a predictor of aseptic loosening. Survivorship of hips with high (≥ 2.7 mm) and low (< 2.7 mm) migration was compared using a competing-events analysis. Femoral components that had aseptic loosening develop showed greater mean distal migration at 24 months postoperatively than did components that remained well fixed throughout the surveillance period (4.2 mm ± 3.1 mm vs 0.8 mm ± 0.9 mm; mean difference, 3.4 mm, 95% CI, 2.5-4.4; p ≤ 0.001). Distal migration at 24 months postoperatively was a strong risk factor for aseptic loosening (hazard ratio, 1.98; 95% CI, 1.51-2.57; p < 0.001). The associated overall diagnostic performance of 2-year distal migration for predicting aseptic loosening was good (area under the ROC curve, 0.86; 95% CI, 0.72-1.00; p < 0.001). Sensitivity of early migration measurement was high for the prediction of aseptic loosening during the first decade after surgery but decreased markedly thereafter. Stems with large amounts of early migration (≥ 2.7 mm) had lower 18-year survivorship than did stems with little early migration (29% [95% CI, 0%-62%] versus 95% [95% CI, 90%-100%] p < 0.001). Early migration, as measured by EBRA-FCA at 2 years postoperatively, has good diagnostic capabilities for detection of uncemented femoral components at risk for aseptic loosening during the first and early second decades after surgery. However, there was no relationship between early migration patterns and aseptic loosening during the late second and third decades. EBRA-FCA can be used as a research tool to evaluate new cementless stems or in clinical practice to evaluate migration patterns in patients with painful femoral components. Level III, diagnostic study.

Systematic evaluation of atmospheric chemistry-transport model CHIMERE

NASA Astrophysics Data System (ADS)

Khvorostyanov, Dmitry; Menut, Laurent; Mailler, Sylvain; Siour, Guillaume; Couvidat, Florian; Bessagnet, Bertrand; Turquety, Solene

2017-04-01

Regional-scale atmospheric chemistry-transport models (CTM) are used to develop air quality regulatory measures, to support environmentally sensitive decisions in the industry, and to address variety of scientific questions involving the atmospheric composition. Model performance evaluation with measurement data is critical to understand their limits and the degree of confidence in model results. CHIMERE CTM (http://www.lmd.polytechnique.fr/chimere/) is a French national tool for operational forecast and decision support and is widely used in the international research community in various areas of atmospheric chemistry and physics, climate, and environment (http://www.lmd.polytechnique.fr/chimere/CW-articles.php). This work presents the model evaluation framework applied systematically to the new CHIMERE CTM versions in the course of the continuous model development. The framework uses three of the four CTM evaluation types identified by the Environmental Protection Agency (EPA) and the American Meteorological Society (AMS): operational, diagnostic, and dynamic. It allows to compare the overall model performance in subsequent model versions (operational evaluation), identify specific processes and/or model inputs that could be improved (diagnostic evaluation), and test the model sensitivity to the changes in air quality, such as emission reductions and meteorological events (dynamic evaluation). The observation datasets currently used for the evaluation are: EMEP (surface concentrations), AERONET (optical depths), and WOUDC (ozone sounding profiles). The framework is implemented as an automated processing chain and allows interactive exploration of the results via a web interface.

Diagnostic Utility of Craving in Predicting Nicotine Dependence: Impact of Craving Content and Item Stability

PubMed Central

2013-01-01

Introduction: Craving is useful in the diagnosis of drug dependence, but it is unclear how various items used to assess craving might influence the diagnostic performance of craving measures. This study determined the diagnostic performance of individual items and item subgroups of the 32-item Questionnaire on Smoking Urges (QSU) as a function of item wording, level of craving intensity, and item stability. Methods: Nondaily and daily smokers (n = 222) completed the QSU on 6 separate occasions, and item responses were averaged across the administrations. Nicotine dependence was assessed with the Wisconsin Inventory of Smoking Dependence Motives. The discriminative performance of the QSU items was evaluated with receiver-operating characteristic curves and area under the curve statistics. Results: Although each of the QSU items and selected subgroups of items significantly discriminated dependent from nondependent smokers, certain item subgroups outperformed others. There was no difference in discriminative performance between use of the specific terms urge and crave or between items assessing intention to smoke relative to those assessing desire to smoke, but there were significant differences in the two major factors represented on the QSU and in craving items reflecting more intense relative to less intense craving. Stability of the item scores was strongly related to the discriminative performance of craving. Conclusions: Items indexing stable, high-intensity aspects of craving that reflect the negative reinforcing effects of smoking will likely be most useful for diagnostic purposes. Future directions and implications are discussed. PMID:23817585

Diagnostic utility of craving in predicting nicotine dependence: impact of craving content and item stability.

PubMed

Germeroth, Lisa J; Wray, Jennifer M; Gass, Julie C; Tiffany, Stephen T

2013-12-01

Craving is useful in the diagnosis of drug dependence, but it is unclear how various items used to assess craving might influence the diagnostic performance of craving measures. This study determined the diagnostic performance of individual items and item subgroups of the 32-item Questionnaire on Smoking Urges (QSU) as a function of item wording, level of craving intensity, and item stability. Nondaily and daily smokers (n = 222) completed the QSU on 6 separate occasions, and item responses were averaged across the administrations. Nicotine dependence was assessed with the Wisconsin Inventory of Smoking Dependence Motives. The discriminative performance of the QSU items was evaluated with receiver-operating characteristic curves and area under the curve statistics. Although each of the QSU items and selected subgroups of items significantly discriminated dependent from nondependent smokers, certain item subgroups outperformed others. There was no difference in discriminative performance between use of the specific terms urge and crave or between items assessing intention to smoke relative to those assessing desire to smoke, but there were significant differences in the two major factors represented on the QSU and in craving items reflecting more intense relative to less intense craving. Stability of the item scores was strongly related to the discriminative performance of craving. Items indexing stable, high-intensity aspects of craving that reflect the negative reinforcing effects of smoking will likely be most useful for diagnostic purposes. Future directions and implications are discussed.

Performance evaluation for pinhole collimators of small gamma camera by MTF and NNPS analysis: Monte Carlo simulation study

NASA Astrophysics Data System (ADS)

Jeon, Hosang; Kim, Hyunduk; Cha, Bo Kyung; Kim, Jong Yul; Cho, Gyuseong; Chung, Yong Hyun; Yun, Jong-Il

2009-06-01

Presently, the gamma camera system is widely used in various medical diagnostic, industrial and environmental fields. Hence, the quantitative and effective evaluation of its imaging performance is essential for design and quality assurance. The National Electrical Manufacturers Association (NEMA) standards for gamma camera evaluation are insufficient to perform sensitive evaluation. In this study, modulation transfer function (MTF) and normalized noise power spectrum (NNPS) will be suggested to evaluate the performance of small gamma camera with changeable pinhole collimators using Monte Carlo simulation. We simulated the system with a cylinder and a disk source, and seven different pinhole collimators from 1- to 4-mm-diameter pinhole with lead. The MTF and NNPS data were obtained from output images and were compared with full-width at half-maximum (FWHM), sensitivity and differential uniformity. In the result, we found that MTF and NNPS are effective and novel standards to evaluate imaging performance of gamma cameras instead of conventional NEMA standards.

Diagnostic accuracy of cone-beam computed tomography in detecting secondary caries under composite fillings: an in vitro study.

PubMed

Yildizer Keris, Elif; Demirel, Oguzhan; Ozdede, Melih; Altunkaynak, Bulent; Peker, Ilkay

2017-01-01

The aim of this in vitro study was to assess the diagnostic performance of cone-beam computed tomography (CBCT) in the detection of secondary carious lesions under composite resin fillings applied to different types of cavities. Occlusal cavities (O) (n=18), occlusal cavities with mesial or distal component (MO/DO) (n=30), and mesial-occlusal-distal cavities (MOD) (n=30) were prepared in seventy eight extracted human posterior teeth. In half of the cavities in each group, artificial secondary caries lesions were simulated. All cavities were restored by using composite resin. All specimens were embedded in silicone and they were positioned to have approximal contacts. CBCT imaging was done and data were evaluated two times with two week interval by two observers, using a five-point confidence scale. Intra- and inter-observer agreements were calculated with Kappa statistics (κ). The area under (Az) the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic accuracy. Intra- (κ =0.89) and inter-observer (κ = 0.79) agreements were found to be excellent. Az values were highest for the O restorations which is followed by the MOD and DO/MO restorations. Az values for MOD and DO/MO restorations were very low and no statistically significant difference was found. Sensitivity for DO/MO restorations and specificity for MOD restorations were found to be the lowest values. Diagnostic performance of CBCT was higher in O composite restorations than MOD and DO/MO restorations for secondary caries detection. The use of alternative imaging methods rather than CBCT may be useful for evaluating secondary caries under composite MOD and DO/MO restorations.

Relationship between radiation dose reduction and image quality change in photostimulable phosphor luminescence X-ray imaging systems.

PubMed

Sakurai, T; Kawamata, R; Kozai, Y; Kaku, Y; Nakamura, K; Saito, M; Wakao, H; Kashima, I

2010-05-01

The aim of the study was to clarify the change in image quality upon X-ray dose reduction and to re-analyse the possibility of X-ray dose reduction in photostimulable phosphor luminescence (PSPL) X-ray imaging systems. In addition, the study attempted to verify the usefulness of multiobjective frequency processing (MFP) and flexible noise control (FNC) for X-ray dose reduction. Three PSPL X-ray imaging systems were used in this study. Modulation transfer function (MTF), noise equivalent number of quanta (NEQ) and detective quantum efficiency (DQE) were evaluated to compare the basic physical performance of each system. Subjective visual evaluation of diagnostic ability for normal anatomical structures was performed. The NEQ, DQE and diagnostic ability were evaluated at base X-ray dose, and 1/3, 1/10 and 1/20 of the base X-ray dose. The MTF of the systems did not differ significantly. The NEQ and DQE did not necessarily depend on the pixel size of the system. The images from all three systems had a higher diagnostic utility compared with conventional film images at the base and 1/3 X-ray doses. The subjective image quality was better at the base X-ray dose than at 1/3 of the base dose in all systems. The MFP and FNC-processed images had a higher diagnostic utility than the images without MFP and FNC. The use of PSPL imaging systems may allow a reduction in the X-ray dose to one-third of that required for conventional film. It is suggested that MFP and FNC are useful for radiation dose reduction.

Climate Model Diagnostic Analyzer

NASA Technical Reports Server (NTRS)

Lee, Seungwon; Pan, Lei; Zhai, Chengxing; Tang, Benyang; Kubar, Terry; Zhang, Zia; Wang, Wei

2015-01-01

The comprehensive and innovative evaluation of climate models with newly available global observations is critically needed for the improvement of climate model current-state representation and future-state predictability. A climate model diagnostic evaluation process requires physics-based multi-variable analyses that typically involve large-volume and heterogeneous datasets, making them both computation- and data-intensive. With an exploratory nature of climate data analyses and an explosive growth of datasets and service tools, scientists are struggling to keep track of their datasets, tools, and execution/study history, let alone sharing them with others. In response, we have developed a cloud-enabled, provenance-supported, web-service system called Climate Model Diagnostic Analyzer (CMDA). CMDA enables the physics-based, multivariable model performance evaluations and diagnoses through the comprehensive and synergistic use of multiple observational data, reanalysis data, and model outputs. At the same time, CMDA provides a crowd-sourcing space where scientists can organize their work efficiently and share their work with others. CMDA is empowered by many current state-of-the-art software packages in web service, provenance, and semantic search.

[Diagnostic validity of the intraoperative analysis in frozen section of the sentinel lymph node in the surgical management of breast cancer].

PubMed

Bañuelos-Andrío, Luis; Rodríguez-Caravaca, Gil; Argüelles-Pintos, Miguel; Mitjavilla-Casanovas, Mercedes

2014-01-01

The method for intraoperative sentinel lymph node (SLN) evaluation has still not been established in breast cancer staging. This study has evaluated the diagnostic validity and impact of intraoperative analysis using the frozen section (FS) of SLN. We performed a descriptive study of the diagnostic validity of the FS of the SLN in patients with breast cancer and selective sentinel node biopsy (SSNB) from October-2006 to October-2012. The diagnostic validity indexes were evaluated using sensitivity, specificity, positive and negative predictive values and global value. Gold standard was considered as the final histopathological results of the biopsies. A total of 370 patients were studied. Sensitivity and specificity for detection of metastasis by FS in the SLN were 67% and 100%, respectively. Global diagnostic validity was 95%. There was a correlation between detection of metastasis and tumor size (p<0.05). Twelve of the 15 patients with SLN micro-metastases underwent axillary lymph node dissection (ALND). Metastatic lymph nodes were not found in any of them. Intraoperative FS examination of the SLN is a useful and reliable predictor of axillary lymph node staging in patients with initial stages of breast cancer. FS reduces the need for second interventions, at least for most patients who have breast cancer with identifiable positive SLN and unequivocal evidence of positive lymph node disease. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

Three-dimensional non-destructive optical evaluation of laser-processing performance using optical coherence tomography.

PubMed

Kim, Youngseop; Choi, Eun Seo; Kwak, Wooseop; Shin, Yongjin; Jung, Woonggyu; Ahn, Yeh-Chan; Chen, Zhongping

2008-06-01

We demonstrate the use of optical coherence tomography (OCT) as a non-destructive diagnostic tool for evaluating laser-processing performance by imaging the features of a pit and a rim. A pit formed on a material at different laser-processing conditions is imaged using both a conventional scanning electron microscope (SEM) and OCT. Then using corresponding images, the geometrical characteristics of the pit are analyzed and compared. From the results, we could verify the feasibility and the potential of the application of OCT to the monitoring of the laser-processing performance.

Three-dimensional non-destructive optical evaluation of laser-processing performance using optical coherence tomography

PubMed Central

Kim, Youngseop; Choi, Eun Seo; Kwak, Wooseop; Shin, Yongjin; Jung, Woonggyu; Ahn, Yeh-Chan; Chen, Zhongping

2014-01-01

We demonstrate the use of optical coherence tomography (OCT) as a non-destructive diagnostic tool for evaluating laser-processing performance by imaging the features of a pit and a rim. A pit formed on a material at different laser-processing conditions is imaged using both a conventional scanning electron microscope (SEM) and OCT. Then using corresponding images, the geometrical characteristics of the pit are analyzed and compared. From the results, we could verify the feasibility and the potential of the application of OCT to the monitoring of the laser-processing performance. PMID:24932051

How does study quality affect the results of a diagnostic meta-analysis?

PubMed Central

Westwood, Marie E; Whiting, Penny F; Kleijnen, Jos

2005-01-01

Background The use of systematic literature review to inform evidence based practice in diagnostics is rapidly expanding. Although the primary diagnostic literature is extensive, studies are often of low methodological quality or poorly reported. There has been no rigorously evaluated, evidence based tool to assess the methodological quality of diagnostic studies. The primary objective of this study was to determine the extent to which variations in the quality of primary studies impact the results of a diagnostic meta-analysis and whether this differs with diagnostic test type. A secondary objective was to contribute to the evaluation of QUADAS, an evidence-based tool for the assessment of quality in diagnostic accuracy studies. Methods This study was conducted as part of large systematic review of tests used in the diagnosis and further investigation of urinary tract infection (UTI) in children. All studies included in this review were assessed using QUADAS, an evidence-based tool for the assessment of quality in systematic reviews of diagnostic accuracy studies. The impact of individual components of QUADAS on a summary measure of diagnostic accuracy was investigated using regression analysis. The review divided the diagnosis and further investigation of UTI into the following three clinical stages: diagnosis of UTI, localisation of infection, and further investigation of the UTI. Each stage used different types of diagnostic test, which were considered to involve different quality concerns. Results Many of the studies included in our review were poorly reported. The proportion of QUADAS items fulfilled was similar for studies in different sections of the review. However, as might be expected, the individual items fulfilled differed between the three clinical stages. Regression analysis found that different items showed a strong association with test performance for the different tests evaluated. These differences were observed both within and between the three clinical stages assessed by the review. The results of regression analyses were also affected by whether or not a weighting (by sample size) was applied. Our analysis was severely limited by the completeness of reporting and the differences between the index tests evaluated and the reference standards used to confirm diagnoses in the primary studies. Few tests were evaluated by sufficient studies to allow meaningful use of meta-analytic pooling and investigation of heterogeneity. This meant that further analysis to investigate heterogeneity could only be undertaken using a subset of studies, and that the findings are open to various interpretations. Conclusion Further work is needed to investigate the influence of methodological quality on the results of diagnostic meta-analyses. Large data sets of well-reported primary studies are needed to address this question. Without significant improvements in the completeness of reporting of primary studies, progress in this area will be limited. PMID:15943861

Can CT imaging features of ground-glass opacity predict invasiveness? A meta-analysis.

PubMed

Dai, Jian; Yu, Guoyou; Yu, Jianqiang

2018-04-01

A meta-analysis was conducted to investigate the diagnostic performance of computed tomography (CT) imaging features of ground-glass opacity (GGO) to predict invasiveness. Two reviewers independently searched PubMed, Medline, Web of Science, Cochrane Embase and CNKI for relevant studies. CT imaging signs of bubble lucency, speculation, lobulated margin, and pleural indentation were used as diagnostic references to discriminate pre-invasive and invasive disease. The sensitivity, specificity, diagnostic odds ratio (DOR), summary receiver operating characteristic (SROC) curves, and the area under the SROC curve (AUC) were calculated to evaluate diagnostic efficiency. Twelve studies were finally included. Diagnostic performance ranged from 0.41 to 0.52 for sensitivity and 0.56 to 0.63 for specificity. The diagnostic positive and negative likelihood ratios ranged from 1.03 to 2.13 and 0.52 to 1.05, respectively. The DORs of the GGO CT features for discriminating invasive disease ranged from 1.02 to 4.00. The area under the ROC curve was also low, with a range of 0.60 to 0.67 for discriminating pre-invasive and invasive disease. The diagnostic value of a single CT imaging sign of GGO, such as bubble lucency, speculation, lobulated margin, or pleural indentation is limited for discriminating pre-invasive and invasive disease because of low sensitivity, specificity, and AUC. © 2018 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

Fitting N-mixture models to count data with unmodeled heterogeneity: Bias, diagnostics, and alternative approaches

USGS Publications Warehouse

Duarte, Adam; Adams, Michael J.; Peterson, James T.

2018-01-01

Monitoring animal populations is central to wildlife and fisheries management, and the use of N-mixture models toward these efforts has markedly increased in recent years. Nevertheless, relatively little work has evaluated estimator performance when basic assumptions are violated. Moreover, diagnostics to identify when bias in parameter estimates from N-mixture models is likely is largely unexplored. We simulated count data sets using 837 combinations of detection probability, number of sample units, number of survey occasions, and type and extent of heterogeneity in abundance or detectability. We fit Poisson N-mixture models to these data, quantified the bias associated with each combination, and evaluated if the parametric bootstrap goodness-of-fit (GOF) test can be used to indicate bias in parameter estimates. We also explored if assumption violations can be diagnosed prior to fitting N-mixture models. In doing so, we propose a new model diagnostic, which we term the quasi-coefficient of variation (QCV). N-mixture models performed well when assumptions were met and detection probabilities were moderate (i.e., ≥0.3), and the performance of the estimator improved with increasing survey occasions and sample units. However, the magnitude of bias in estimated mean abundance with even slight amounts of unmodeled heterogeneity was substantial. The parametric bootstrap GOF test did not perform well as a diagnostic for bias in parameter estimates when detectability and sample sizes were low. The results indicate the QCV is useful to diagnose potential bias and that potential bias associated with unidirectional trends in abundance or detectability can be diagnosed using Poisson regression. This study represents the most thorough assessment to date of assumption violations and diagnostics when fitting N-mixture models using the most commonly implemented error distribution. Unbiased estimates of population state variables are needed to properly inform management decision making. Therefore, we also discuss alternative approaches to yield unbiased estimates of population state variables using similar data types, and we stress that there is no substitute for an effective sample design that is grounded upon well-defined management objectives.

White Sands Missile Range Overview & Introduction: Test Capabilities Briefing

DTIC Science & Technology

2011-11-07

PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Army Test and Evaluation Command (ATEC),White Sands Missile Range,White Sands Missile Range,NM,88002...5000 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR...solar radiation, icing, salt fog, etc. • Instrumented for system performance / diagnostics  Climatics testing capabilities • Fixed and mobile test

Integrating Oil Debris and Vibration Gear Damage Detection Technologies Using Fuzzy Logic

NASA Technical Reports Server (NTRS)

Dempsey, Paula J.; Afjeh, Abdollah A.

2002-01-01

A diagnostic tool for detecting damage to spur gears was developed. Two different measurement technologies, wear debris analysis and vibration, were integrated into a health monitoring system for detecting surface fatigue pitting damage on gears. This integrated system showed improved detection and decision-making capabilities as compared to using individual measurement technologies. This diagnostic tool was developed and evaluated experimentally by collecting vibration and oil debris data from fatigue tests performed in the NASA Glenn Spur Gear Fatigue Test Rig. Experimental data were collected during experiments performed in this test rig with and without pitting. Results show combining the two measurement technologies improves the detection of pitting damage on spur gears.

Spiral Bevel Gear Damage Detection Using Decision Fusion Analysis

NASA Technical Reports Server (NTRS)

Dempsey, Paula J.; Handschuh, Robert F.; Afjeh, Abdollah A.

2002-01-01

A diagnostic tool for detecting damage to spiral bevel gears was developed. Two different monitoring technologies, oil debris analysis and vibration, were integrated using data fusion into a health monitoring system for detecting surface fatigue pitting damage on gears. This integrated system showed improved detection and decision-making capabilities as compared to using individual monitoring technologies. This diagnostic tool was evaluated by collecting vibration and oil debris data from fatigue tests performed in the NASA Glenn Spiral Bevel Gear Fatigue Rigs. Data was collected during experiments performed in this test rig when pitting damage occurred. Results show that combining the vibration and oil debris measurement technologies improves the detection of pitting damage on spiral bevel gears.

[When should a patient with abdominal pain be referred to the emergency ward?].

PubMed

de Saussure, Wassila Oulhaci; Andereggen, Elisabeth; Sarasin, François

2010-08-25

When should a patient with abdominal pain be referred to the emergency ward? The following goals must be achieved upon managing patients with acute abdominal pain: 1) identify vital emergency situations; 2) detect surgical conditions that require emergency referral without further diagnostic procedures; 3) in "non surgical acute abdomen patients" perform appropriate diagnostic procedures, or in selected cases delay tests and reevaluate the patient after an observation period, after which a referral decision is made. Clues from the history and physical examination are critical to perform this evaluation. A good knowledge of the most frequent acute abdominal conditions, and identifying potential severity criteria allow an appropriate management and decision about emergency referral.

Meta-Review of CSF Core Biomarkers in Alzheimer’s Disease: The State-of-the-Art after the New Revised Diagnostic Criteria

PubMed Central

Ferreira, Daniel; Perestelo-Pérez, Lilisbeth; Westman, Eric; Wahlund, Lars-Olof; Sarría, Antonio; Serrano-Aguilar, Pedro

2014-01-01

Background: Current research criteria for Alzheimer’s disease (AD) include cerebrospinal fluid (CSF) biomarkers into the diagnostic algorithm. However, spreading their use to the clinical routine is still questionable. Objective: To provide an updated, systematic and critical review on the diagnostic utility of the CSF core biomarkers for AD. Data sources: MEDLINE, PreMedline, EMBASE, PsycInfo, CINAHL, Cochrane Library, and CRD. Eligibility criteria: (1a) Systematic reviews with meta-analysis; (1b) Primary studies published after the new revised diagnostic criteria; (2) Evaluation of the diagnostic performance of at least one CSF core biomarker. Results: The diagnostic performance of CSF biomarkers is generally satisfactory. They are optimal for discriminating AD patients from healthy controls. Their combination may also be suitable for mild cognitive impairment (MCI) prognosis. However, CSF biomarkers fail to distinguish AD from other forms of dementia. Limitations: (1) Use of clinical diagnosis as standard instead of pathological postmortem confirmation; (2) variability of methodological aspects; (3) insufficiently long follow-up periods in MCI studies; and (4) lower diagnostic accuracy in primary care compared with memory clinics. Conclusion: Additional work needs to be done to validate the application of CSF core biomarkers as they are proposed in the new revised diagnostic criteria. The use of CSF core biomarkers in clinical routine is more likely if these limitations are overcome. Early diagnosis is going to be of utmost importance when effective pharmacological treatment will be available and the CSF core biomarkers can also be implemented in clinical trials for drug development. PMID:24715863

Thermal Analysis of a Disposable, Instrument-Free DNA Amplification Lab-on-a-Chip Platform.

PubMed

Pardy, Tamás; Rang, Toomas; Tulp, Indrek

2018-06-04

Novel second-generation rapid diagnostics based on nucleic acid amplification tests (NAAT) offer performance metrics on par with clinical laboratories in detecting infectious diseases at the point of care. The diagnostic assay is typically performed within a Lab-on-a-Chip (LoC) component with integrated temperature regulation. However, constraints on device dimensions, cost and power supply inherent with the device format apply to temperature regulation as well. Thermal analysis on simplified thermal models for the device can help overcome these barriers by speeding up thermal optimization. In this work, we perform experimental thermal analysis on the simplified thermal model for our instrument-free, single-use LoC NAAT platform. The system is evaluated further by finite element modelling. Steady-state as well as transient thermal analysis are performed to evaluate the performance of a self-regulating polymer resin heating element in the proposed device geometry. Reaction volumes in the target temperature range of the amplification reaction are estimated in the simulated model to assess compliance with assay requirements. Using the proposed methodology, we demonstrated our NAAT device concept capable of performing loop-mediated isothermal amplification in the 20⁻25 °C ambient temperature range with 32 min total assay time.

A Rotatable Quality Control Phantom for Evaluating the Performance of Flat Panel Detectors in Imaging Moving Objects.

PubMed

Haga, Yoshihiro; Chida, Koichi; Inaba, Yohei; Kaga, Yuji; Meguro, Taiichiro; Zuguchi, Masayuki

2016-02-01

As the use of diagnostic X-ray equipment with flat panel detectors (FPDs) has increased, so has the importance of proper management of FPD systems. To ensure quality control (QC) of FPD system, an easy method for evaluating FPD imaging performance for both stationary and moving objects is required. Until now, simple rotatable QC phantoms have not been available for the easy evaluation of the performance (spatial resolution and dynamic range) of FPD in imaging moving objects. We developed a QC phantom for this purpose. It consists of three thicknesses of copper and a rotatable test pattern of piano wires of various diameters. Initial tests confirmed its stable performance. Our moving phantom is very useful for QC of FPD images of moving objects because it enables visual evaluation of image performance (spatial resolution and dynamic range) easily.

Comparative Evaluation of the Diagnostic Performance of the Prototype Cepheid GeneXpert Ebola Assay

PubMed Central

Jansen van Vuren, Petrus; Grobbelaar, Antoinette; Storm, Nadia; Conteh, Ousman; Konneh, Kelfala; Kamara, Abdul; Sanne, Ian

2015-01-01

The Ebola virus disease (EVD) outbreak in West Africa has highlighted an urgent need for point-of-care (POC) assays for the diagnosis of this devastating disease in resource-limited African countries. The diagnostic performance characteristics of a prototype Cepheid GeneXpert Ebola POC used to detect Ebola virus (EBOV) in stored serum and plasma samples collected from suspected EVD cases in Sierra Leone in 2014 and 2015 was evaluated. The GeneXpert Ebola POC is a self-contained single-cartridge automated system that targets the glycoprotein (GP) and nucleoprotein (NP) genes of EBOV and yields results within 90 min. Results from 281 patient samples were compared to the results of a TaqMan real-time reverse transcription-PCR (RT-PCR) targeting the polymerase gene and performed on two real-time PCR machines. Agreement between the three platforms was 100% at cycle threshold (CT) values of ≤34.99, but discordant results were noted between CT values of 35 and 45.The diagnostic sensitivity of the three platforms was 100% in 91 patient samples that were confirmed to be infectious by virus isolation. All three molecular platforms detected viral EBOV RNA in additional samples that did not contain viable EBOV. The analytical sensitivity of the GeneXpert Ebola POC for the detection of NP was higher, and comparable to that of polymerase gene detection, than that for the detection of GP when using a titrated laboratory stock of EBOV. There was no detectable cross-reactivity with other hemorrhagic fever viruses or arboviruses. The GeneXpert Ebola POC offers an easy to operate and sensitive diagnostic tool that can be used for the rapid screening of suspected EVD cases in treatment or in holding centers during EVD outbreaks. PMID:26637383

Discrepancy between the clinical and histopathologic diagnosis of soft tissue vascular malformations.

PubMed

Horbach, Sophie E R; Utami, Amalia M; Meijer-Jorna, Lorine B; Sillevis Smitt, J H; Spuls, Phyllis I; van der Horst, Chantal M A M; van der Wal, Allard C

2017-11-01

Soft tissue vascular malformations are generally diagnosed clinically, according to the International Society for the Study of Vascular Anomalies (ISSVA) classification. Diagnostic histopathologic examination is rarely performed. We sought to evaluate the validity of the current diagnostic workup without routinely performed diagnostic histopathology. We retrospectively determined whether there were discrepancies between clinical and histopathologic diagnoses of patients with clinically diagnosed vascular malformations undergoing therapeutic surgical resections in our center (2000-2015). Beforehand, a pathologist revised the histopathologic diagnoses according to the ISSVA classification. Clinical and histopathologic diagnoses were discrepant in 57% of 142 cases. In these cases, the pathologist indicated the diagnosis was not at all a vascular malformation (n = 24; 17%), a completely different type of vascular malformation (n = 26; 18%), or a partially different type with regard to the combination of vessel-types involved (n = 31; 22%). Possible factors associated with the discrepancies were both clinician-related (eg, diagnostic uncertainty) and pathology-related (eg, lack of immunostaining). Retrospective analysis of a subgroup of patients undergoing surgery. The large discrepancy between clinical and histopathologic diagnoses raises doubt about the validity of the current diagnostic workup for vascular malformations. Clear clinical and histopathologic diagnostic criteria might be essential for a uniform diagnosis. Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Diagnosis of Polycystic Ovary Syndrome: AMH in combination with clinical symptoms.

PubMed

Sahmay, Sezai; Aydin, Yavuz; Oncul, Mahmut; Senturk, Levent M

2014-02-01

We assessed the utility of using anti-Müllerian hormone (AMH) and clinical features of polycystic ovary syndrome (PCOS), polycystic ovarian morphology (PCOM), oligo/amenorrhea (OA), and hyperandrogenism (HA) for diagnosing PCOS, and compared their diagnostic accuracy with those of classical diagnostic systems. A total of 606 females were admitted to a university hospital with menstrual irregularities or symptoms of hyperandrogenism were enrolled in this cross-sectional study. Fasting blood samples were collected. Pelvic and/or abdominal ultrasonography and clinical examination were performed. Patients were evaluated for the presence of PCOS according to conventional diagnostic criteria. The diagnostic performance of using serum AMH levels alone and in various combinations with the clinical features of PCOM, OA, and HA were investigated. For the diagnosis of PCOS, the combination of OA and/or HA with AMH showed 83% sensitivity and 100% specificity according to the Rotterdam criteria; 83% sensitivity and 89% specificity according to the National Institutes of Health (NIH) criteria; and 82% sensitivity and 93.5% specificity according to the Androgen Excess Society (AES) criteria. The serum AMH level is a useful diagnostic marker for PCOS and is correlated with conventional diagnostic criteria. The combination of AMH level with OA and/or HA markedly increased the clinical scope for PCOS diagnosis and can be introduced as a possible objective criterion for the diagnosis of this disease.

The diagnostic management of upper extremity deep vein thrombosis: A review of the literature.

PubMed

Kraaijpoel, Noémie; van Es, Nick; Porreca, Ettore; Büller, Harry R; Di Nisio, Marcello

2017-08-01

Upper extremity deep vein thrombosis (UEDVT) accounts for 4% to 10% of all cases of deep vein thrombosis. UEDVT may present with localized pain, erythema, and swelling of the arm, but may also be detected incidentally by diagnostic imaging tests performed for other reasons. Prompt and accurate diagnosis is crucial to prevent pulmonary embolism and long-term complications as the post-thrombotic syndrome of the arm. Unlike the diagnostic management of deep vein thrombosis (DVT) of the lower extremities, which is well established, the work-up of patients with clinically suspected UEDVT remains uncertain with limited evidence from studies of small size and poor methodological quality. Currently, only one prospective study evaluated the use of an algorithm, similar to the one used for DVT of the lower extremities, for the diagnostic workup of clinically suspected UEDVT. The algorithm combined clinical probability assessment, D-dimer testing and ultrasonography and appeared to safely and effectively exclude UEDVT. However, before recommending its use in routine clinical practice, external validation of this strategy and improvements of the efficiency are needed, especially in high-risk subgroups in whom the performance of the algorithm appeared to be suboptimal, such as hospitalized or cancer patients. In this review, we critically assess the accuracy and efficacy of current diagnostic tools and provide clinical guidance for the diagnostic management of clinically suspected UEDVT. Copyright © 2017 Elsevier Ltd. All rights reserved.

Economic evaluation of diagnostic methods used in dentistry. A systematic review.

PubMed

Christell, Helena; Birch, Stephen; Horner, Keith; Lindh, Christina; Rohlin, Madeleine

2014-11-01

To review the literature of economic evaluations regarding diagnostic methods used in dentistry. Four databases (MEDLINE, Web of Science, The Cochrane library, the NHS Economic Evaluation Database) were searched for studies, complemented by hand search, until February 2013. Two authors independently screened all titles or abstracts and then applied inclusion and exclusion criteria to select full-text publications published in English, which reported an economic evaluation comparing at least two alternative methods. Studies of diagnostic methods were assessed by four reviewers using a protocol based on the QUADAS tool regarding diagnostic methods and a check-list for economic evaluations. The results of the data extraction were summarized in a structured table and as a narrative description. From 476 identified full-text publications, 160 were considered to be economic evaluations. Only 12 studies (7%) were on diagnostic methods, whilst 78 studies (49%) were on prevention and 70 (40%) on treatment. Among studies on diagnostic methods, there was between-study heterogeneity methodologically, regarding the diagnostic method analysed and type of economic evaluation addressed. Generally, the choice of economic evaluation method was not justified and the perspective of the study not stated. Costing of diagnostic methods varied. A small body of literature addresses economic evaluation of diagnostic methods in dentistry. Thus, there is a need for studies from various perspectives with well defined research questions and measures of the cost and effectiveness. Economic resources in healthcare are finite. For diagnostic methods, an understanding of efficacy provides only part of the information needed for evidence-based practice. This study highlighted a paucity of economic evaluations of diagnostic methods used in dentistry, indicating that much of what we practise lacks sufficient evidence.

ENO1 Overexpression in Pancreatic Cancer Patients and Its Clinical and Diagnostic Significance

PubMed Central

Yin, Hang; Wang, Lei

2018-01-01

We investigated in this study the expression of ENO1 in tissues and plasma of PDAC patients to evaluate its clinicopathological and diagnostic significance. ENO1 protein expression was detected in tissue microarray of human PDAC and adjacent noncancer tissues. Electrochemiluminescence immunoassay and amplified luminescent proximity homogeneous assay (AlphaLISA) were performed to measure CA19-9 and ENO1 concentration in plasma from PDAC patients and healthy controls. We demonstrated that ENO1 overexpression is positively correlated with clinical stage, lymph node metastasis, and poor prognosis of PDAC; ENO1 may function as a hopeful candidate diagnostic marker in combination with CA19-9 in PDAC diagnosis. PMID:29483925

Inverse probability weighting estimation of the volume under the ROC surface in the presence of verification bias.

PubMed

Zhang, Ying; Alonzo, Todd A

2016-11-01

In diagnostic medicine, the volume under the receiver operating characteristic (ROC) surface (VUS) is a commonly used index to quantify the ability of a continuous diagnostic test to discriminate between three disease states. In practice, verification of the true disease status may be performed only for a subset of subjects under study since the verification procedure is invasive, risky, or expensive. The selection for disease examination might depend on the results of the diagnostic test and other clinical characteristics of the patients, which in turn can cause bias in estimates of the VUS. This bias is referred to as verification bias. Existing verification bias correction in three-way ROC analysis focuses on ordinal tests. We propose verification bias-correction methods to construct ROC surface and estimate the VUS for a continuous diagnostic test, based on inverse probability weighting. By applying U-statistics theory, we develop asymptotic properties for the estimator. A Jackknife estimator of variance is also derived. Extensive simulation studies are performed to evaluate the performance of the new estimators in terms of bias correction and variance. The proposed methods are used to assess the ability of a biomarker to accurately identify stages of Alzheimer's disease. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Training Needs Analysis: Weaknesses in the Conventional Approach.

ERIC Educational Resources Information Center

Leat, Michael James; Lovel, Murray Jack

1997-01-01

Identification of the training and development needs of administrative support staff is not aided by conventional performance appraisal, which measures summary or comparative effectiveness. Meaningful diagnostic evaluation integrates three levels of analysis (organization, task, and individual), using behavioral expectation scales. (SK)

Congenital hypothyroidism: diagnostic scintigraphic evaluation of an organification defect

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cone, L.; Oates, E.; Vazquez, R.

1988-06-01

Quantitative Tc-99m pertechnetate thyroid imaging was performed on a hypothyroid neonate. The image revealed markedly increased trapping in an enlarged, bilobed, eutopic gland. A perchlorate washout test using quantitative imaging with I-123 confirmed an organification problem.

Performance of the Delirium Rating Scale-Revised-98 Against Different Delirium Diagnostic Criteria in a Population With a High Prevalence of Dementia.

PubMed

Sepulveda, Esteban; Franco, José G; Trzepacz, Paula T; Gaviria, Ana M; Viñuelas, Eva; Palma, José; Ferré, Gisela; Grau, Imma; Vilella, Elisabet

2015-01-01

Delirium diagnosis in elderly is often complicated by underlying dementia. We evaluated performance of the Delirium Rating Scale-Revised-98 (DRS-R98) in patients with high dementia prevalence and also assessed concordance among past and current diagnostic criteria for delirium. Cross-sectional analysis of newly admitted patients to a skilled nursing facility over 6 months, who were rated within 24-48 hours after admission. Interview for Diagnostic and Statistical Manual of Mental Disorders, 3rd edition-R (DSM)-III-R, DSM-IV, DSM-5, and International Classification of Diseases 10th edition delirium ratings, administration of the DRS-R98, and assessment of dementia using the Informant Questionnaire on Cognitive Decline in the Elderly were independently performed by 3 researchers. Discriminant analyses (receiver operating characteristics curves) were used to study DRS-R98 accuracy against different diagnostic criteria. Hanley and McNeil test compared the area under the curve for DRS-R98's discriminant performance for all diagnostic criteria. Dementia was present in 85/125 (68.0%) subjects, and 36/125 (28.8%) met criteria for delirium by at least 1 classification system, whereas only 19/36 (52.8%) did by all. DSM-III-R diagnosed the most as delirious (27.2%), followed by DSM-5 (24.8%), DSM-IV-TR (22.4%), and International Classification of Diseases 10th edition (16%). DRS-R98 had the highest AUC when discriminating DSM-III-R delirium (92.9%), followed by DSM-IV (92.4%), DSM-5 (91%), and International Classification of Diseases 10th edition (90.5%), without statistical differences among them. The best DRS-R98 cutoff score was ≥14.5 for all diagnostic systems except International Classification of Diseases 10th edition (≥15.5). There is a low concordance across diagnostic systems for identification of delirium. The DRS-R98 performs well despite differences across classification systems perhaps because it broadly assesses phenomenology, even in this population with a high prevalence of dementia. Copyright © 2015 The Academy of Psychosomatic Medicine. Published by Elsevier Inc. All rights reserved.

Diagnostic Yield of CT-Guided Percutaneous Transthoracic Needle Biopsy for Diagnosis of Anterior Mediastinal Masses.

PubMed

Petranovic, Milena; Gilman, Matthew D; Muniappan, Ashok; Hasserjian, Robert P; Digumarthy, Subba R; Muse, Victorine V; Sharma, Amita; Shepard, Jo-Anne O; Wu, Carol C

2015-10-01

The purpose of this study was to evaluate the diagnostic yield and accuracy of CT-guided percutaneous biopsy of anterior mediastinal masses and assess prebiopsy characteristics that may help to select patients with the highest diagnostic yield. Retrospective review of all CT-guided percutaneous biopsies of the anterior mediastinum conducted at our institution from January 2003 through December 2012 was performed to collect data regarding patient demographics, imaging characteristics of biopsied masses, presence of complications, and subsequent surgical intervention or medical treatment (or both). Cytology, core biopsy pathology, and surgical pathology results were recorded. A per-patient analysis was performed using two-tailed t test, Fisher's exact test, and Pearson chi-square test. The study cohort included 52 patients (32 men, 20 women; mean age, 49 years) with mean diameter of mediastinal mass of 6.9 cm. Diagnostic yield of CT-guided percutaneous biopsy was 77% (40/52), highest for thymic neoplasms (100% [11/11]). Non-diagnostic results were seen in 12 of 52 patients (23%), primarily in patients with lymphoma (75% [9/12]). Fine-needle aspiration yielded the correct diagnosis in 31 of 52 patients (60%), and core biopsy had a diagnostic rate of 77% (36/47). None of the core biopsies were discordant with surgical pathology. There was no statistically significant difference between the diagnostic and the nondiagnostic groups in patient age, lesion size, and presence of necrosis. The complication rate was 3.8% (2/52), all small self-resolving pneumothoraces. CT-guided percutaneous biopsy is a safe diagnostic procedure with high diagnostic yield (77%) for anterior mediastinal lesions, highest for thymic neoplasms (100%), and can potentially obviate more invasive procedures.

Evaluating and Measuring the Return on Investment of an Emergency Center Health Care Professional Picture Archiving and Communication Systems Training Program

ERIC Educational Resources Information Center

Roelandt, James P.

2012-01-01

Picture archiving and communication system (PACS) workflow directly affects the quality of emergency patient care through radiology exam turn-around times and the speed of delivery of diagnostic radiology results. This study was a mixed methods training and performance improvement study that evaluated the effectiveness and value of a hospital…

The role of technetium-99m stannous pyrophosphate in myocardial imaging to recognize, localize and identify extension of acute myocardial infarction in patients

NASA Technical Reports Server (NTRS)

Willerson, J. T.; Parkey, R. W.; Bonte, F. J.; Stokely, E. M.; Buja, E. M.

1975-01-01

The ability of technetium-99m stannous pyrophosphate myocardial scintigrams to aid diagnostically in recognizing, localizing, and identifying extension of acute myocardial infarction in patients was evaluated. The present study is an extension of previous animal and patient evaluations that were recently performed utilizing this myocardial imaging agent.

Evaluation of computer-aided detection and diagnosis systems.

PubMed

Petrick, Nicholas; Sahiner, Berkman; Armato, Samuel G; Bert, Alberto; Correale, Loredana; Delsanto, Silvia; Freedman, Matthew T; Fryd, David; Gur, David; Hadjiiski, Lubomir; Huo, Zhimin; Jiang, Yulei; Morra, Lia; Paquerault, Sophie; Raykar, Vikas; Samuelson, Frank; Summers, Ronald M; Tourassi, Georgia; Yoshida, Hiroyuki; Zheng, Bin; Zhou, Chuan; Chan, Heang-Ping

2013-08-01

Computer-aided detection and diagnosis (CAD) systems are increasingly being used as an aid by clinicians for detection and interpretation of diseases. Computer-aided detection systems mark regions of an image that may reveal specific abnormalities and are used to alert clinicians to these regions during image interpretation. Computer-aided diagnosis systems provide an assessment of a disease using image-based information alone or in combination with other relevant diagnostic data and are used by clinicians as a decision support in developing their diagnoses. While CAD systems are commercially available, standardized approaches for evaluating and reporting their performance have not yet been fully formalized in the literature or in a standardization effort. This deficiency has led to difficulty in the comparison of CAD devices and in understanding how the reported performance might translate into clinical practice. To address these important issues, the American Association of Physicists in Medicine (AAPM) formed the Computer Aided Detection in Diagnostic Imaging Subcommittee (CADSC), in part, to develop recommendations on approaches for assessing CAD system performance. The purpose of this paper is to convey the opinions of the AAPM CADSC members and to stimulate the development of consensus approaches and "best practices" for evaluating CAD systems. Both the assessment of a standalone CAD system and the evaluation of the impact of CAD on end-users are discussed. It is hoped that awareness of these important evaluation elements and the CADSC recommendations will lead to further development of structured guidelines for CAD performance assessment. Proper assessment of CAD system performance is expected to increase the understanding of a CAD system's effectiveness and limitations, which is expected to stimulate further research and development efforts on CAD technologies, reduce problems due to improper use, and eventually improve the utility and efficacy of CAD in clinical practice.

Evaluation of computer-aided detection and diagnosis systemsa)

PubMed Central

Petrick, Nicholas; Sahiner, Berkman; Armato, Samuel G.; Bert, Alberto; Correale, Loredana; Delsanto, Silvia; Freedman, Matthew T.; Fryd, David; Gur, David; Hadjiiski, Lubomir; Huo, Zhimin; Jiang, Yulei; Morra, Lia; Paquerault, Sophie; Raykar, Vikas; Samuelson, Frank; Summers, Ronald M.; Tourassi, Georgia; Yoshida, Hiroyuki; Zheng, Bin; Zhou, Chuan; Chan, Heang-Ping

2013-01-01

Computer-aided detection and diagnosis (CAD) systems are increasingly being used as an aid by clinicians for detection and interpretation of diseases. Computer-aided detection systems mark regions of an image that may reveal specific abnormalities and are used to alert clinicians to these regions during image interpretation. Computer-aided diagnosis systems provide an assessment of a disease using image-based information alone or in combination with other relevant diagnostic data and are used by clinicians as a decision support in developing their diagnoses. While CAD systems are commercially available, standardized approaches for evaluating and reporting their performance have not yet been fully formalized in the literature or in a standardization effort. This deficiency has led to difficulty in the comparison of CAD devices and in understanding how the reported performance might translate into clinical practice. To address these important issues, the American Association of Physicists in Medicine (AAPM) formed the Computer Aided Detection in Diagnostic Imaging Subcommittee (CADSC), in part, to develop recommendations on approaches for assessing CAD system performance. The purpose of this paper is to convey the opinions of the AAPM CADSC members and to stimulate the development of consensus approaches and “best practices” for evaluating CAD systems. Both the assessment of a standalone CAD system and the evaluation of the impact of CAD on end-users are discussed. It is hoped that awareness of these important evaluation elements and the CADSC recommendations will lead to further development of structured guidelines for CAD performance assessment. Proper assessment of CAD system performance is expected to increase the understanding of a CAD system's effectiveness and limitations, which is expected to stimulate further research and development efforts on CAD technologies, reduce problems due to improper use, and eventually improve the utility and efficacy of CAD in clinical practice. PMID:23927365

Diagnostic imaging and radiation exposure in inflammatory bowel disease.

PubMed

Zakeri, Nekisa; Pollok, Richard C G

2016-02-21

Diagnostic imaging plays a key role in the diagnosis and management of inflammatory bowel disease (IBD). However due to the relapsing nature of IBD, there is growing concern that IBD patients may be exposed to potentially harmful cumulative levels of ionising radiation in their lifetime, increasing malignant potential in a population already at risk. In this review we explore the proportion of IBD patients exposed to high cumulative radiation doses, the risk factors associated with higher radiation exposures, and we compare conventional diagnostic imaging with newer radiation-free imaging techniques used in the evaluation of patients with IBD. While computed tomography (CT) performs well as an imaging modality for IBD, the effective radiation dose is considerably higher than other abdominal imaging modalities. It is increasingly recognised that CT imaging remains responsible for the majority of diagnostic medical radiation to which IBD patients are exposed. Magnetic resonance imaging (MRI) and small intestine contrast enhanced ultrasonography (SICUS) have now emerged as suitable radiation-free alternatives to CT imaging, with comparable diagnostic accuracy. The routine use of MRI and SICUS for the clinical evaluation of patients with known or suspected small bowel Crohn's disease is to be encouraged wherever possible. More provision is needed for out-of-hours radiation-free imaging modalities to reduce the need for CT.

Diagnostic imaging and radiation exposure in inflammatory bowel disease

PubMed Central

Zakeri, Nekisa; Pollok, Richard CG

2016-01-01

Diagnostic imaging plays a key role in the diagnosis and management of inflammatory bowel disease (IBD). However due to the relapsing nature of IBD, there is growing concern that IBD patients may be exposed to potentially harmful cumulative levels of ionising radiation in their lifetime, increasing malignant potential in a population already at risk. In this review we explore the proportion of IBD patients exposed to high cumulative radiation doses, the risk factors associated with higher radiation exposures, and we compare conventional diagnostic imaging with newer radiation-free imaging techniques used in the evaluation of patients with IBD. While computed tomography (CT) performs well as an imaging modality for IBD, the effective radiation dose is considerably higher than other abdominal imaging modalities. It is increasingly recognised that CT imaging remains responsible for the majority of diagnostic medical radiation to which IBD patients are exposed. Magnetic resonance imaging (MRI) and small intestine contrast enhanced ultrasonography (SICUS) have now emerged as suitable radiation-free alternatives to CT imaging, with comparable diagnostic accuracy. The routine use of MRI and SICUS for the clinical evaluation of patients with known or suspected small bowel Crohn’s disease is to be encouraged wherever possible. More provision is needed for out-of-hours radiation-free imaging modalities to reduce the need for CT. PMID:26900282

The diagnostic performance evaluation of the SD BIOLINE HIV/syphilis Duo rapid test in southern Ethiopia: a cross-sectional study

PubMed Central

Shimelis, Techalew; Tadesse, Endale

2015-01-01

Objective To determine the diagnostic performance of the SD BIOLINE HIV/syphilis Duo rapid test. Design A hospital-based cross-sectional study. Setting This evaluation was conducted at one of the largest hospitals in southern Ethiopia. Participants Serum samples obtained from clients attending the antiretroviral therapy and voluntary counselling and testing centres were used. Sera were originally collected for the purpose of investigating syphilis epidemiology. The performance of the test to detect HIV was evaluated using 400 sera (200 HIV positives and 200 HIV negatives). Also, its performance to detect syphilis was evaluated using 85 syphilis positive and 100 syphilis negative serum samples. Individuals <15 years of age or syphilis treated or those with ≤50 cells/µL CD4 cell count were originally excluded. Outcome measures HIV screening was carried out according to the national rapid diagnostic testing (RDT) algorithm: Shenghai Kehua Bioengineering (KHB) test kit as a screening test, followed by the HIV1/2 STAT-PAK assay if positive. Where the result of the STAT-PAK is discordant with KHB, Unigold HIV is used as a tiebreaker to determine the result. We also used ELISA to resolve discordant HIV results. Syphilis serostatus was determined using the Treponema pallidum haemagglutination assay (TPHA). Results The respective sensitivity, specificity, positive predictive value and negative predictive value of the SD BIOLINE HIV/syphilis Duo test were 100, 99.5, 99.5 and 100% for HIV and 97.6, 96, 95.4 and 98% for syphilis testing, respectively. In reference to TPHA, the test kit reported 4 false positives and 2 false negative results for syphilis. The κ values were 0.99 for HIV testing and 0.94 for syphilis testing. Conclusions The excellent performance of the SD BIOLINE HIV/syphilis Duo test to detect HIV as well as syphilis facilitates the integration of syphilis testing and treatment to the already established HIV prevention programme, ultimately contributing to the dual HIV and syphilis elimination goal. PMID:25908677

The diagnostic performance evaluation of the SD BIOLINE HIV/syphilis Duo rapid test in southern Ethiopia: a cross-sectional study.

PubMed

Shimelis, Techalew; Tadesse, Endale

2015-04-23

To determine the diagnostic performance of the SD BIOLINE HIV/syphilis Duo rapid test. A hospital-based cross-sectional study. This evaluation was conducted at one of the largest hospitals in southern Ethiopia. Serum samples obtained from clients attending the antiretroviral therapy and voluntary counselling and testing centres were used. Sera were originally collected for the purpose of investigating syphilis epidemiology. The performance of the test to detect HIV was evaluated using 400 sera (200 HIV positives and 200 HIV negatives). Also, its performance to detect syphilis was evaluated using 85 syphilis positive and 100 syphilis negative serum samples. Individuals <15 years of age or syphilis treated or those with ≤50 cells/µL CD4 cell count were originally excluded. HIV screening was carried out according to the national rapid diagnostic testing (RDT) algorithm: Shenghai Kehua Bioengineering (KHB) test kit as a screening test, followed by the HIV1/2 STAT-PAK assay if positive. Where the result of the STAT-PAK is discordant with KHB, Unigold HIV is used as a tiebreaker to determine the result. We also used ELISA to resolve discordant HIV results. Syphilis serostatus was determined using the Treponema pallidum haemagglutination assay (TPHA). The respective sensitivity, specificity, positive predictive value and negative predictive value of the SD BIOLINE HIV/syphilis Duo test were 100, 99.5, 99.5 and 100% for HIV and 97.6, 96, 95.4 and 98% for syphilis testing, respectively. In reference to TPHA, the test kit reported 4 false positives and 2 false negative results for syphilis. The κ values were 0.99 for HIV testing and 0.94 for syphilis testing. The excellent performance of the SD BIOLINE HIV/syphilis Duo test to detect HIV as well as syphilis facilitates the integration of syphilis testing and treatment to the already established HIV prevention programme, ultimately contributing to the dual HIV and syphilis elimination goal. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Impact of arrhythmia on diagnostic performance of adenosine stress CMR in patients with suspected or known coronary artery disease.

PubMed

Greulich, Simon; Steubing, Hannah; Birkmeier, Stefan; Grün, Stefan; Bentz, Kerstin; Sechtem, Udo; Mahrholdt, Heiko

2015-11-05

The diagnostic performance of adenosine stress cardiovascular magnetic resonance (CMR) in patients with arrhythmias presenting for work-up of suspected or known CAD is largely unknown, since most CMR studies currently available exclude arrhythmic patients from analysis fearing gating problems, or other artifacts will impair image quality. The primary aim of our study was to evaluate the diagnostic performance of adenosine stress CMR for detection of significant coronary stenosis in patients with arrhythmia presenting for 1) work-up of suspected coronary artery disease (CAD), or 2) work-up of ischemia in known CAD. Patients with arrhythmia referred for work-up of suspected CAD or work-up of ischemia in known CAD undergoing adenosine stress CMR were included if they had coronary angiography within four weeks of CMR. One hundred fifty-nine patients were included (n = 64 atrial fibrillation, n = 87 frequent ventricular extrasystoles, n = 8 frequent supraventricular extrasystoles). Of these, n = 72 had suspected CAD, and n = 87 had known CAD. Diagnostic accuracy of the adenosine stress CMR for detection of significant CAD was 73 % for the entire population (sensitivity 72 %, specificity 76 %). Diagnostic accuracy was 75 % (sensitivity 80 %, specificity 74 %) in patients with suspected CAD, and 74 % (sensitivity 71 %, specificity 79 %) in the group with known CAD. For different types of arrhythmia, diagnostic accuracy of CMR was 70 % in the atrial fibrillation group, and 79 % in patients with ventricular extrasystoles. On a per coronary territory analysis, diagnostic accuracy of CMR was 77 % for stenosis of the left and 82 % for stenosis of the right coronary artery. The present data demonstrates good diagnostic performance of adenosine stress CMR for detection of significant coronary stenosis in patients with arrhythmia presenting for work-up of suspected CAD, or work-up of ischemia in known CAD. This holds true for a per patient, as well as for a per coronary territory analysis.

WE-G-217BCD-04: Diagnostic Image Quality Evaluation of a Dedicated Extremity Cone- Beam CT Scanner: Pre-Clinical Studies and First Clinical Results.

PubMed

Muhit, A; Zbijewski, W; Stayman, J; Thawait, G; Yorkston, J; Foos, D; Packard, N; Yang, D; Senn, R; Carrino, J; Siewerdsen, J

2012-06-01

To assess the diagnostic performance of a prototype cone-beam CT (CBCT) scanner developed for musculoskeletal extremity imaging. Studies involved controlled observer studies conducted subsequent to rigorous technical assessment as well as patient images from the first clinical trial in imaging the hand and knee. Performance assessment included: 1.) rigorous technical assessment; 2.) controlled observer studies using CBCT images of cadaveric specimens; and 3.) first clinical images. Technical assessment included measurement of spatial resolution (MTF), constrast, and noise (SDNR) versus kVp and dose using standard CT phantoms. Diagnostic performance in comparison to multi- detector CT (MDCT) was assessed in controlled observer studies involving 12 cadaveric hands and knees scanned with and without abnormality (fracture). Observer studies involved five radiologists rating pertinent diagnostics tasks in 9-point preference and 10-point diagnostic satisfaction scales. Finally, the first clinical images from an ongoing pilot study were assessed in terms of diagnostic utility in disease assessment and overall workflow in patient setup. Quantitative assessment demonstrated sub-mm spatial resolution (MTF exceeding 10% out to 15-20 cm-1) and SDNR sufficient for relevant soft-tissue visualization tasks at dose <10 mGy. Observer studies confirmed optimal acquisition techniques and demonstrated superior utility of combined soft-tissue visualization and isotropic spatial resolution in diagnostic tasks. Images from the patient trial demonstrate exquisite contrast and detail and the ability to detect tissue impingement in weight-bearing exams. The prototype CBCT scanner provides isotropic spatial resolution superior to standard-protocol MDCT with soft-tissue visibility sufficient for a broad range of diagnostic tasks in musculoskeletal radiology. Dosimetry and workflow were advantageous in comparison to whole-body MDCT. Multi-mode and weight-bearing capabilities add valuable functionality. An ongoing clinical study further assesses diagnostic utility and defines the role of such technology in the diagnostic arsenal. - Research Grant, Carestream Health - Research Grant, National Institutes of Health 2R01-CA-112163. © 2012 American Association of Physicists in Medicine.

A diagnosis of bipolar spectrum disorder predicts diagnostic conversion from unipolar depression to bipolar disorder: a 5-year retrospective study.

PubMed

Woo, Young Sup; Shim, In Hee; Wang, Hee-Ryung; Song, Hoo Rim; Jun, Tae-Youn; Bahk, Won-Myong

2015-03-15

The major aims of this study were to identify factors that may predict the diagnostic conversion from major depressive disorder (MDD) to bipolar disorder (BP) and to evaluate the predictive performance of the bipolar spectrum disorder (BPSD) diagnostic criteria. The medical records of 250 patients with a diagnosis of MDD for at least 5 years were retrospectively reviewed for this study. The diagnostic conversion from MDD to BP was observed in 18.4% of 250 MDD patients, and the diagnostic criteria for BPSD predicted this conversion with high sensitivity (0.870) and specificity (0.917). A family history of BP, antidepressant-induced mania/hypomania, brief major depressive episodes, early age of onset, antidepressant wear-off, and antidepressant resistance were also independent predictors of this conversion. This study was conducted using a retrospective design and did not include structured diagnostic interviews. The diagnostic criteria for BPSD were highly predictive of the conversion from MDD to BP, and conversion was associated with several clinical features of BPSD. Thus, the BPSD diagnostic criteria may be useful for the prediction of bipolar diathesis in MDD patients. Copyright © 2014 Elsevier B.V. All rights reserved.

Performance evaluation of a chemiluminescence microparticle immunoassay for CK-MB.

PubMed

Lin, Zhi-Yuan; Fang, Yi-Zhen; Jin, Hong-Wei; Lin, Hua-Yue; Dai, Zhang; Luo, Qing; Li, Hong-Wei; Lin, Yan-Ling; Huang, Shui-Zhen; Gao, Lei; Xu, Fei-Hai; Zhang, Zhong-Ying

2018-03-31

To verify and evaluate the performance characteristics of a creatine kinase phosphokinase isoenzymes MB (CK-MB) assay kit, which produced by Xiamen Innodx Biotech Co. Ltd. Evaluation was carried out according to "Guidelines for principle of analysis performance evaluation of in vitro diagnostic reagent." The performance parameters included detection limit, linearity range, reportable range, recovery test, precision verification, interference test, cross-reactivity, matrix effect, and method comparison. The detection limit was 0.1 ng/mL. The assay had clinical linearity over range of 0.1 ng/mL-500 ng/mL. Reportable range was from 0.1 ng/mL to 1000 ng/mL. The average percent of recovery was 99.66%. The coefficient of variation (CV) for within-run and between-run of low CK-MB sample was 5.55% and 6.16%, respectively. As for high-level sample, it was 7.88% and 7.80%. In medical decision level, the relative deviation (Bias) of all interference tests was lower than 15%. When the sample had mild-hemolysis; hemoglobin ≤15 g/L; triglyceride ≤17 mmol/L; bilirubin ≤427.5 μmol/L; rheumatoid factor ≤206U/mL, there was no significant interference to be found. Moreover, assay kit had no cross-reaction with CK-MM and CK-BB. At last, total diagnostic accuracy of kit was 93.24%, when compared with refer kit. Overall the results of the verification study indicated the performance of kit is met the requirements of the clinical test. © 2018 Wiley Periodicals, Inc.

Interactive visualisation for interpreting diagnostic test accuracy study results.

PubMed

Fanshawe, Thomas R; Power, Michael; Graziadio, Sara; Ordóñez-Mena, José M; Simpson, John; Allen, Joy

2018-02-01

Information about the performance of diagnostic tests is typically presented in the form of measures of test accuracy such as sensitivity and specificity. These measures may be difficult to translate directly into decisions about patient treatment, for which information presented in the form of probabilities of disease after a positive or a negative test result may be more useful. These probabilities depend on the prevalence of the disease, which is likely to vary between populations. This article aims to clarify the relationship between pre-test (prevalence) and post-test probabilities of disease, and presents two free, online interactive tools to illustrate this relationship. These tools allow probabilities of disease to be compared with decision thresholds above and below which different treatment decisions may be indicated. They are intended to help those involved in communicating information about diagnostic test performance and are likely to be of benefit when teaching these concepts. A substantive example is presented using C reactive protein as a diagnostic marker for bacterial infection in the older adult population. The tools may also be useful for manufacturers of clinical tests in planning product development, for authors of test evaluation studies to improve reporting and for users of test evaluations to facilitate interpretation and application of the results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Diagnostic performance of serological tests to detect antibodies against acute scrub typhus infection in central India.

PubMed

Pote, Kiran; Narang, Rahul; Deshmukh, Pradeep

2018-01-01

Differentiating scrub typhus from other acute febrile illness is difficult due to non specificity of clinical symptoms and relative absence of eschar in Indian population. The diagnosis thus relies mainly on laboratory tests. Antibody based serological tests are mainstay of scrub typhus diagnosis. Here, we evaluated the diagnostic performance of IgM ELISA, IgM IFA and ICT to detect antibodies against O. tsutsugamushi in acute serum of febrile patients. The serum samples from 600 randomly selected patients suffering from acute undifferentiated fever were tested by all the three tests mentioned above. We used latent class analysis to generate unbiased results as all the tests for scrub typhus diagnosis are imperfect and none of them can be considered as reference standard. We found that IgM ELISA with cutoff titer 0.5 OD has high diagnostic accuracy (sensitivity 99.9% and specificity 99.15) than IgM IFA (sensitivity 96.8% and specificity 99.7%) for scrub typhus diagnosis. ICT used in our study had very high specificity 100% but low sensitivity (38%) which would limit its use for acute serum samples. ICT being a screening or point of care test, has to be more sensitive while some compromise with specificity is affordable. Hence, optimal cutoff for ICT should be evaluated under different settings. IgM ELISA being simple and affordable could be an alternative diagnostic test to IgM IFA which is subjective and costly.

Wisteria floribunda Agglutinin and Its Reactive-Glycan-Carrying Prostate-Specific Antigen as a Novel Diagnostic and Prognostic Marker of Prostate Cancer

PubMed Central

Hagiwara, Kazuhisa; Tobisawa, Yuki; Kaya, Takatoshi; Kaneko, Tomonori; Hatakeyama, Shingo; Mori, Kazuyuki; Hashimoto, Yasuhiro; Koie, Takuya; Suda, Yoshihiko; Ohyama, Chikara; Yoneyama, Tohru

2017-01-01

Wisteria floribunda agglutinin (WFA) preferably binds to LacdiNAc glycans, and its reactivity is associated with tumor progression. The aim of this study to examine whether the serum LacdiNAc carrying prostate-specific antigen–glycosylation isomer (PSA-Gi) and WFA-reactivity of tumor tissue can be applied as a diagnostic and prognostic marker of prostate cancer (PCa). Between 2007 and 2016, serum PSA-Gi levels before prostate biopsy (Pbx) were measured in 184 biopsy-proven benign prostatic hyperplasia patients and 244 PCa patients using an automated lectin-antibody immunoassay. WFA-reactivity on tumor was analyzed in 260 radical prostatectomy (RP) patients. Diagnostic and prognostic performance of serum PSA-Gi was evaluated using area under the receiver-operator characteristic curve (AUC). Prognostic performance of WFA-reactivity on tumor was evaluated via Cox proportional hazards regression analysis and nomogram. The AUC of serum PSA-Gi detecting PCa and predicting Pbx Grade Group (GG) 3 and GG ≥ 3 after RP was much higher than those of conventional PSA. Multivariate analysis showed that WFA-reactivity on prostate tumor was an independent risk factor of PSA recurrence. The nomogram was a strong model for predicting PSA-free survival provability with a c-index ≥0.7. Serum PSA-Gi levels and WFA-reactivity on prostate tumor may be a novel diagnostic and pre- and post-operative prognostic biomarkers of PCa, respectively. PMID:28134773

Wisteria floribunda Agglutinin and Its Reactive-Glycan-Carrying Prostate-Specific Antigen as a Novel Diagnostic and Prognostic Marker of Prostate Cancer.

PubMed

Hagiwara, Kazuhisa; Tobisawa, Yuki; Kaya, Takatoshi; Kaneko, Tomonori; Hatakeyama, Shingo; Mori, Kazuyuki; Hashimoto, Yasuhiro; Koie, Takuya; Suda, Yoshihiko; Ohyama, Chikara; Yoneyama, Tohru

2017-01-26

Wisteria floribunda agglutinin (WFA) preferably binds to LacdiNAc glycans, and its reactivity is associated with tumor progression. The aim of this study to examine whether the serum LacdiNAc carrying prostate-specific antigen-glycosylation isomer (PSA-Gi) and WFA-reactivity of tumor tissue can be applied as a diagnostic and prognostic marker of prostate cancer (PCa). Between 2007 and 2016, serum PSA-Gi levels before prostate biopsy (Pbx) were measured in 184 biopsy-proven benign prostatic hyperplasia patients and 244 PCa patients using an automated lectin-antibody immunoassay. WFA-reactivity on tumor was analyzed in 260 radical prostatectomy (RP) patients. Diagnostic and prognostic performance of serum PSA-Gi was evaluated using area under the receiver-operator characteristic curve (AUC). Prognostic performance of WFA-reactivity on tumor was evaluated via Cox proportional hazards regression analysis and nomogram. The AUC of serum PSA-Gi detecting PCa and predicting Pbx Grade Group (GG) 3 and GG ≥ 3 after RP was much higher than those of conventional PSA. Multivariate analysis showed that WFA-reactivity on prostate tumor was an independent risk factor of PSA recurrence. The nomogram was a strong model for predicting PSA-free survival provability with a c -index ≥0.7. Serum PSA-Gi levels and WFA-reactivity on prostate tumor may be a novel diagnostic and pre- and post-operative prognostic biomarkers of PCa, respectively.

Rapid and simple detection of foot-and-mouth disease virus: Evaluation of a cartridge-based molecular detection system for use in basic laboratories.

PubMed

Goller, K V; Dill, V; Madi, M; Martin, P; Van der Stede, Y; Vandenberge, V; Haas, B; Van Borm, S; Koenen, F; Kasanga, C J; Ndusilo, N; Beer, M; Liu, L; Mioulet, V; Armson, B; King, D P; Fowler, V L

2018-04-01

Highly contagious transboundary animal diseases such as foot-and-mouth disease (FMD) are major threats to the productivity of farm animals. To limit the impact of outbreaks and to take efficient steps towards a timely control and eradication of the disease, rapid and reliable diagnostic systems are of utmost importance. Confirmatory diagnostic assays are typically performed by experienced operators in specialized laboratories, and access to this capability is often limited in the developing countries with the highest disease burden. Advances in molecular technologies allow implementation of modern and reliable techniques for quick and simple pathogen detection either in basic laboratories or even at the pen-side. Here, we report on a study to evaluate a fully automated cartridge-based real-time RT-PCR diagnostic system (Enigma MiniLab ® ) for the detection of FMD virus (FMDV). The modular system integrates both nucleic acid extraction and downstream real-time RT-PCR (rRT-PCR). The analytical sensitivity of this assay was determined using serially diluted culture grown FMDV, and the performance of the assay was evaluated using a selected range of FMDV positive and negative clinical samples of bovine, porcine and ovine origin. The robustness of the assay was evaluated in an international inter-laboratory proficiency test and by deployment into an African laboratory. It was demonstrated that the system is easy to use and can detect FMDV with high sensitivity and specificity, roughly on par with standard laboratory methods. This cartridge-based automated real-time RT-PCR system for the detection of FMDV represents a reliable and easy to use diagnostic tool for the early and rapid disease detection of acutely infected animals even in remote areas. This type of system could be easily deployed for routine surveillance within endemic regions such as Africa or could alternatively be used in the developed world. © 2017 The Authors. Transboundary and Emerging Diseases Published by Blackwell Verlag GmbH.

[Cytology in uropathological diagnostics].

PubMed

Gaisa, N T; Lindemann-Docter, K

2015-11-01

Cytology in uropathological diagnostics is mainly performed for oncological purposes. The assessment of malignancy by urothelial cell morphology is therefore decisive; however, cytology is only sensitive enough to detect high-grade tumor cells and the different low-grade tumors cannot be reliably diagnosed. Thus, the four-tier classification system of cytological findings (i.e. negative, atypical cells but significance uncertain, suspicious and positive) refers to high-grade tumor cells only. Furthermore, for valid cytological diagnostics not only the cytological specimen but also clinical information on cystoscopy findings and, if applicable, a biopsy should be evaluated together. In difficult differential diagnostic settings, e.g. differentiation between reactive versus neoplastic atypia or difficult to access lesions in the upper urinary tract, additional fluorescence in situ hybridization of cytological preparations might be helpful. At the moment there are no indications for further immunocytology or additional biomarker tests.

Endoscopic ultrasound cytologic brushing vs endoscopic ultrasound: fine needle aspiration for cytological diagnosis of cystic pancreatic lesions. A multicenter, randomized open-label trial.

PubMed

Lariño-Noia, José; de la Iglesia, Daniel; Iglesias-García, Julio; Macías, Manuel; López Martín, Aurelio; Legaz, María Luisa; Vila, Juan; Reyes, Antonio; Abdulkader, Ihab; Domínguez-Muñoz, J Enrique

2018-04-24

the incidence of cystic pancreatic lesions (CPL) in the asymptomatic population is increasing. Achieving a preoperative diagnosis of CPL still remains a challenge. to evaluate the diagnostic accuracy of the cytological diagnosis of CPL from samples obtained by cytology brush versus standard endoscopic ultrasound fine needle aspiration (EUS-FNA). a multicenter, randomized, open-label trial was performed of EUS-cytology brush (EUS-EB) versus EUS-FNA for the cytological diagnosis of CPL. Patients that underwent EUS-FNA with a CPL > 15 mm were included and randomized into two groups: group I, EUS-EB; group II, EUS-FNA. The final diagnosis was based on the histological evaluation of surgical specimens and clinical parameters, imaging and a five year follow-up in non-operated patients. The main outcome was the diagnostic accuracy of both methods. Secondary outcomes were the diagnostic adequacy of specimens and the rate of adverse events. Data were compared using the Chi-squared test. An intention to treat (ITT) and per-protocol (PP) analysis were performed. sixty-five patients were included in the study, 31 in group I and 34 in group II. Three patients initially randomized to group I were changed to group II as it was impossible to obtain a sample using the brush. The mean size of the CPL was 28.2 mm (range 16-60 mm). The diagnostic accuracy of EUS-EB was not superior to EUS-FNA, neither in the ITT nor the PP analysis (44.8% vs 41.1%, p = 0.77 and 38.4% vs 45.9%, p = 0.55). EUS-EB does not improve the diagnostic accuracy of CPL in comparison with EUS-FNA.

Comparison of Core-Needle Biopsy and Fine-Needle Aspiration for Evaluating Thyroid Incidentalomas Detected by 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: A Propensity Score Analysis.

PubMed

Suh, Chong Hyun; Choi, Young Jun; Lee, Jong Jin; Shim, Woo Hyun; Baek, Jung Hwan; Chung, Han Cheol; Shong, Young Kee; Song, Dong Eun; Sung, Tae Yon; Lee, Jeong Hyun

2017-10-01

This study used a propensity score analysis to assess the roles of core-needle biopsy (CNB) and fine-needle aspiration (FNA) in the evaluation of thyroid incidentalomas detected on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT). The study population was obtained from a historical cohort who underwent 18 F-FDG PET/CT between October 2008 and September 2015. Patients were included who underwent ultrasound-guided CNB or FNA for incidental focal uptake of 18 F-FDG in the thyroid gland on PET/CT. The primary study outcomes included the inconclusive result rates in the CNB and FNA groups. The secondary outcome measures included the non-diagnostic result rate and the diagnostic performance for neoplasms. Multivariate analysis, propensity score matching, and inverse probability weighting were conducted. A total of 1360 nodules from 1338 patients were included in this study: 859 nodules from 850 patients underwent FNA, and 501 nodules from 488 patients underwent CNB. Compared to FNA, CNB demonstrated a significantly lower inconclusive result rate in the pooled cohort (23.8% vs. 35.4%; p < 0.001), propensity score-matched cohorts (22.9% vs. 36.6%; p < 0.001), and with inverse probability weighting (22.4% vs. 35.2%; p < 0.001). Non-diagnostic result rates were also significantly lower in CNB than in FNA. The diagnostic performance of the two groups in the pooled and matched cohorts was similar, with no significant differences found. The significantly lower inconclusive result rates in CNB than in FNA were consistent within the propensity score-matched cohorts. Therefore, CNB appears to be a promising diagnostic tool for patients with thyroid incidentalomas detected on 18 F-FDG PET/CT.

The use of intrathecal analgesia and contrast radiography as preoperative diagnostic methods for digital flexor tendon sheath pathology.

PubMed

Fiske-Jackson, A R; Barker, W H J; Eliashar, E; Foy, K; Smith, R K W

2013-01-01

The sensitivity of ultrasonography for the diagnosis of manica flexoria (MF) tears within the digital flexor tendon sheath (DFTS) is lower than for diagnosis of marginal tears of the deep digital flexor tendon (DDFT). Additional diagnostic tools would assist in appropriate decision making for either conservative or surgical management. To evaluate the improvement in lameness of horses with MF or DDFT tears following intrathecal analgesia and to assess the sensitivity and specificity of contrast radiography for the diagnosis of these tears. The case records of horses presented to a referral clinic over a 7-year period that underwent intrathecal diagnostic analgesia, or intrathecal analgesia and contrast radiography, of the DFTS with subsequent tenoscopy were examined. Fifty-three limbs had intrathecal diagnostic analgesia performed and 23 contrast tenograms were assessed in horses undergoing DFTS tenoscopy. Horses with DDFT tears were significantly more likely to respond positively to intrathecal diagnostic analgesia than those with MF tears (P = 0.02). Using contrast radiography, tears of the MF were predicted with an overall sensitivity of 96% and specificity of 80%; marginal tears of the DDFT were predicted with an overall sensitivity of 57% and specificity of 84%. The results of intrathecal analgesia of the DFTS in combination with contrast radiography have a high sensitivity for predicting MF tears. The sensitivity of contrast radiography for predicting tears of the DDFT is lower but the specificity remains high. Contrast radiography performed at the same time as intrathecal analgesia provides useful information regarding the presence of MF tears and DDFT tears, which can assist in the decision of whether to manage the lameness conservatively or with tenoscopic evaluation. © 2012 EVJ Ltd.

Evaluating the accessibility and utility of HIV-related point-of-care diagnostics for maternal health in rural South Africa: a study protocol

PubMed Central

Mashamba-Thompson, T P; Drain, P K; Sartorius, B

2016-01-01

Introduction Poor healthcare access is a major barrier to receiving antenatal care and a cause of high maternal mortality in South Africa (SA). ‘Point-of-care’ (POC) diagnostics is a powerful emerging healthcare approach to improve healthcare access. This study focuses on evaluating the accessibility and utility of POC diagnostics for maternal health in rural SA primary healthcare (PHC) clinics in order to generate a model framework of implementation of POC diagnostics in rural South African clinics. Method and analyses We will use several research methods, including a systematic review, quasi-experiments, survey, key informant interviews and audits. We will conduct a systematic review and experimental study to determine the impact of POC diagnostics on maternal health. We will perform a cross-sectional case study of 100 randomly selected rural primary healthcare clinics in KwaZulu-Natal to measure the context and patterns of POC diagnostics access and usage by maternal health providers and patients. We will conduct interviews with relevant key stakeholders to determine the reasons for POC deficiencies regarding accessibility and utility of HIV-related POC diagnostics for maternal health. We will also conduct a vertical audit to investigate all the quality aspects of POC diagnostic services including diagnostic accuracy in a select number of clinics. On the basis of information gathered, we will propose a model framework for improved implementation of POC diagnostics in rural South African public healthcare clinics. Statistical (Stata-13) and thematic (NVIVO) data analysis will be used in this study. Ethics and dissemination The study protocol was approved by the Ethics Committee of the University of KwaZulu-Natal (BE 484/14) and the KwaZulu-Natal Department of Health based on the Helsinki Declaration (HRKM 40/15). Findings of this study will be disseminated electronically and in print. They will be presented to conferences related to HIV/AIDS, diagnostics, maternal health and strengthening of health systems. PMID:27354074

Design and performance evaluation of a 20-aperture multipinhole collimator for myocardial perfusion imaging applications.

PubMed

Bowen, Jason D; Huang, Qiu; Ellin, Justin R; Lee, Tzu-Cheng; Shrestha, Uttam; Gullberg, Grant T; Seo, Youngho

2013-10-21

Single photon emission computed tomography (SPECT) myocardial perfusion imaging remains a critical tool in the diagnosis of coronary artery disease. However, after more than three decades of use, photon detection efficiency remains poor and unchanged. This is due to the continued reliance on parallel-hole collimators first introduced in 1964. These collimators possess poor geometric efficiency. Here we present the performance evaluation results of a newly designed multipinhole collimator with 20 pinhole apertures (PH20) for commercial SPECT systems. Computer simulations and numerical observer studies were used to assess the noise, bias and diagnostic imaging performance of a PH20 collimator in comparison with those of a low energy high resolution (LEHR) parallel-hole collimator. Ray-driven projector/backprojector pairs were used to model SPECT imaging acquisitions, including simulation of noiseless projection data and performing MLEM/OSEM image reconstructions. Poisson noise was added to noiseless projections for realistic projection data. Noise and bias performance were investigated for five mathematical cardiac and torso (MCAT) phantom anatomies imaged at two gantry orbit positions (19.5 and 25.0 cm). PH20 and LEHR images were reconstructed with 300 MLEM iterations and 30 OSEM iterations (ten subsets), respectively. Diagnostic imaging performance was assessed by a receiver operating characteristic (ROC) analysis performed on a single MCAT phantom; however, in this case PH20 images were reconstructed with 75 pixel-based OSEM iterations (four subsets). Four PH20 projection views from two positions of a dual-head camera acquisition and 60 LEHR projections were simulated for all studies. At uniformly-imposed resolution of 12.5 mm, significant improvements in SNR and diagnostic sensitivity (represented by the area under the ROC curve, or AUC) were realized when PH20 collimators are substituted for LEHR parallel-hole collimators. SNR improves by factors of 1.94-2.34 for the five patient anatomies and two orbital positions studied. For the ROC analysis the PH20 AUC is larger than the LEHR AUC with a p-value of 0.0067. Bias performance, however, decreases with the use of PH20 collimators. Systematic analyses showed PH20 collimators present improved diagnostic imaging performance over LEHR collimators, requiring only collimator exchange on existing SPECT cameras for their use.

Design and performance evaluation of a 20-aperture multipinhole collimator for myocardial perfusion imaging applications

NASA Astrophysics Data System (ADS)

Bowen, Jason D.; Huang, Qiu; Ellin, Justin R.; Lee, Tzu-Cheng; Shrestha, Uttam; Gullberg, Grant T.; Seo, Youngho

2013-10-01

Single photon emission computed tomography (SPECT) myocardial perfusion imaging remains a critical tool in the diagnosis of coronary artery disease. However, after more than three decades of use, photon detection efficiency remains poor and unchanged. This is due to the continued reliance on parallel-hole collimators first introduced in 1964. These collimators possess poor geometric efficiency. Here we present the performance evaluation results of a newly designed multipinhole collimator with 20 pinhole apertures (PH20) for commercial SPECT systems. Computer simulations and numerical observer studies were used to assess the noise, bias and diagnostic imaging performance of a PH20 collimator in comparison with those of a low energy high resolution (LEHR) parallel-hole collimator. Ray-driven projector/backprojector pairs were used to model SPECT imaging acquisitions, including simulation of noiseless projection data and performing MLEM/OSEM image reconstructions. Poisson noise was added to noiseless projections for realistic projection data. Noise and bias performance were investigated for five mathematical cardiac and torso (MCAT) phantom anatomies imaged at two gantry orbit positions (19.5 and 25.0 cm). PH20 and LEHR images were reconstructed with 300 MLEM iterations and 30 OSEM iterations (ten subsets), respectively. Diagnostic imaging performance was assessed by a receiver operating characteristic (ROC) analysis performed on a single MCAT phantom; however, in this case PH20 images were reconstructed with 75 pixel-based OSEM iterations (four subsets). Four PH20 projection views from two positions of a dual-head camera acquisition and 60 LEHR projections were simulated for all studies. At uniformly-imposed resolution of 12.5 mm, significant improvements in SNR and diagnostic sensitivity (represented by the area under the ROC curve, or AUC) were realized when PH20 collimators are substituted for LEHR parallel-hole collimators. SNR improves by factors of 1.94-2.34 for the five patient anatomies and two orbital positions studied. For the ROC analysis the PH20 AUC is larger than the LEHR AUC with a p-value of 0.0067. Bias performance, however, decreases with the use of PH20 collimators. Systematic analyses showed PH20 collimators present improved diagnostic imaging performance over LEHR collimators, requiring only collimator exchange on existing SPECT cameras for their use.

Evaluation of velocity-sensitized and acceleration-sensitized NCE-MRA for below-knee peripheral arterial disease.

PubMed

Shaida, Nadeem; Priest, Andrew N; See, T C; Winterbottom, Andrew P; Graves, Martin J; Lomas, David J

2017-06-01

To evaluate the diagnostic performance of velocity- and acceleration-sensitized noncontrast-enhanced magnetic resonance angiography (NCE-MRA) of the infrageniculate arteries using contrast-enhanced MRA (CE-MRA) as a reference standard. Twenty-four patients with symptoms of peripheral arterial disease were recruited. Each patient's infrageniculate arterial tree was examined using a velocity-dependent flow-sensitized dephasing (VEL-FSD) technique, an acceleration-dependent (ACC-FSD) technique, and our conventional CE-MRA technique performed at 1.5T. The images were independently reviewed by two experienced vascular radiologists, who evaluated each vessel segment to assess visibility, diagnostic confidence, venous contamination, and detection of pathology. In all, 432 segments were evaluated by each of the three techniques by each reader in total. Overall diagnostic confidence was rated as moderate or high in 98.5% of segments with CE-MRA, 92.1% with VEL-FSD, and 79.9% with ACC-FSD. No venous contamination was seen in 96% of segments with CE-MRA, 72.2% with VEL-FSD, and 85.8% with ACC-FSD. Per-segment, per-limb, and per-patient sensitivities for detecting significant stenotic disease were 63.4%, 73%, and 92%, respectively, for ACC-FSD, and 65.3%, 87.2%, and 96% for VEL-FSD, and as such no significant statistical change was detected using McNemar's chi-squared test with P-values of 1.00, 0.13, and 0.77 obtained, respectively. Flow-dependent NCE-MRA techniques may have a role to play in evaluation of patients with peripheral vascular disease. Increased sensitivity of a velocity-based technique compared to an acceleration-based technique comes at the expense of greater venous contamination. 2J. Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;45:1846-1853. © 2016 International Society for Magnetic Resonance in Medicine.

Dynamic CT myocardial perfusion imaging: performance of 3D semi-automated evaluation software.

PubMed

Ebersberger, Ullrich; Marcus, Roy P; Schoepf, U Joseph; Lo, Gladys G; Wang, Yining; Blanke, Philipp; Geyer, Lucas L; Gray, J Cranston; McQuiston, Andrew D; Cho, Young Jun; Scheuering, Michael; Canstein, Christian; Nikolaou, Konstantin; Hoffmann, Ellen; Bamberg, Fabian

2014-01-01

To evaluate the performance of three-dimensional semi-automated evaluation software for the assessment of myocardial blood flow (MBF) and blood volume (MBV) at dynamic myocardial perfusion computed tomography (CT). Volume-based software relying on marginal space learning and probabilistic boosting tree-based contour fitting was applied to CT myocardial perfusion imaging data of 37 subjects. In addition, all image data were analysed manually and both approaches were compared with SPECT findings. Study endpoints included time of analysis and conventional measures of diagnostic accuracy. Of 592 analysable segments, 42 showed perfusion defects on SPECT. Average analysis times for the manual and software-based approaches were 49.1 ± 11.2 and 16.5 ± 3.7 min respectively (P < 0.01). There was strong agreement between the two measures of interest (MBF, ICC = 0.91, and MBV, ICC = 0.88, both P < 0.01) and no significant difference in MBF/MBV with respect to diagnostic accuracy between the two approaches for both MBF and MBV for manual versus software-based approach; respectively; all comparisons P > 0.05. Three-dimensional semi-automated evaluation of dynamic myocardial perfusion CT data provides similar measures and diagnostic accuracy to manual evaluation, albeit with substantially reduced analysis times. This capability may aid the integration of this test into clinical workflows. • Myocardial perfusion CT is attractive for comprehensive coronary heart disease assessment. • Traditional image analysis methods are cumbersome and time-consuming. • Automated 3D perfusion software shortens analysis times. • Automated 3D perfusion software increases standardisation of myocardial perfusion CT. • Automated, standardised analysis fosters myocardial perfusion CT integration into clinical practice.

Regulatory perspectives and research activities at the FDA on the use of phantoms with in vivo diagnostic devices

NASA Astrophysics Data System (ADS)

Agrawal, Anant; Gavrielides, Marios A.; Weininger, Sandy; Chakrabarti, Kish; Pfefer, Joshua

2008-02-01

For a number of years, phantoms have been used to optimize device parameters and validate performance in the primary medical imaging modalities (CT, MRI, PET/SPECT, ultrasound). Furthermore, the FDA under the Mammography Quality Standards Act (MQSA) requires image quality evaluation of mammography systems using FDA-approved phantoms. The oldest quantitative optical diagnostic technology, pulse oximetry, also benefits from the use of active phantoms known as patient simulators to validate certain performance characteristics under different clinically-relevant conditions. As such, guidance provided by the FDA to its staff and to industry on the contents of pre-market notification and approval submissions includes suggestions on how to incorporate the appropriate phantoms in establishing device effectiveness. Research at the FDA supports regulatory statements on the use of phantoms by investigating how phantoms can be designed, characterized, and utilized to determine critical device performance characteristics. These examples provide a model for how novel techniques in the rapidly growing field of optical diagnostics can use phantoms during pre- and post-market regulatory testing.

Accuracy of biochemical markers for predicting nasogastric tube placement in adults--a systematic review of diagnostic studies.

PubMed

Fernandez, Ritin S; Chau, Janita Pak-Chun; Thompson, David R; Griffiths, Rhonda; Lo, Hoi-Shan

2010-08-01

The objective of this study was to investigate the diagnostic performance of biochemical tests used to determine placement of nasogastric (NG) tubes after insertion in adults. A systematic review of diagnostic studies was undertaken. A literature search of the bibliographic databases and the World Wide Web was performed to locate original diagnostic studies in English or Chinese on biochemical markers for detecting NG tube location. Studies in which one or more different tests were evaluated with a reference standard, and diagnostic values were reported or could be calculated were included. Two reviewers independently checked all abstracts and full text studies for inclusion criteria. Included studies were assessed for their quality using the QUADAS tool. Study features and diagnostic values were extracted from the included studies. Of the 10 studies included in this review, seven investigated the diagnostic accuracy of pH, one investigated the diagnostic accuracy of pH and bilirubin respectively, two a combination of pH and bilirubin and one a combination of pH, pepsin and trypsin levels in identifying NG tube location. All studies used X-rays as the reference standard for comparison. Pooled results demonstrated that a pH of

Diagnostic accuracy of imaging devices in glaucoma: A meta-analysis.

PubMed

Fallon, Monica; Valero, Oliver; Pazos, Marta; Antón, Alfonso

Imaging devices such as the Heidelberg retinal tomograph-3 (HRT3), scanning laser polarimetry (GDx), and optical coherence tomography (OCT) play an important role in glaucoma diagnosis. A systematic search for evidence-based data was performed for prospective studies evaluating the diagnostic accuracy of HRT3, GDx, and OCT. The diagnostic odds ratio (DOR) was calculated. To compare the accuracy among instruments and parameters, a meta-analysis considering the hierarchical summary receiver-operating characteristic model was performed. The risk of bias was assessed using quality assessment of diagnostic accuracy studies, version 2. Studies in the context of screening programs were used for qualitative analysis. Eighty-six articles were included. The DOR values were 29.5 for OCT, 18.6 for GDx, and 13.9 for HRT. The heterogeneity analysis demonstrated statistically a significant influence of degree of damage and ethnicity. Studies analyzing patients with earlier glaucoma showed poorer results. The risk of bias was high for patient selection. Screening studies showed lower sensitivity values and similar specificity values when compared with those included in the meta-analysis. The classification capabilities of GDx, HRT, and OCT were high and similar across the 3 instruments. The highest estimated DOR was obtained with OCT. Diagnostic accuracy could be overestimated in studies including prediagnosed groups of subjects. Copyright © 2017 Elsevier Inc. All rights reserved.

Prognostic and health management of active assets in nuclear power plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agarwal, Vivek; Lybeck, Nancy; Pham, Binh T.

This study presents the development of diagnostic and prognostic capabilities for active assets in nuclear power plants (NPPs). The research was performed under the Advanced Instrumentation, Information, and Control Technologies Pathway of the Light Water Reactor Sustainability Program. Idaho National Laboratory researched, developed, implemented, and demonstrated diagnostic and prognostic models for generator step-up transformers (GSUs). The Fleet-Wide Prognostic and Health Management (FW-PHM) Suite software developed by the Electric Power Research Institute was used to perform diagnosis and prognosis. As part of the research activity, Idaho National Laboratory implemented 22 GSU diagnostic models in the Asset Fault Signature Database and twomore » wellestablished GSU prognostic models for the paper winding insulation in the Remaining Useful Life Database of the FW-PHM Suite. The implemented models along with a simulated fault data stream were used to evaluate the diagnostic and prognostic capabilities of the FW-PHM Suite. Knowledge of the operating condition of plant asset gained from diagnosis and prognosis is critical for the safe, productive, and economical long-term operation of the current fleet of NPPs. This research addresses some of the gaps in the current state of technology development and enables effective application of diagnostics and prognostics to nuclear plant assets.« less

Prognostic and health management of active assets in nuclear power plants

DOE PAGES

Agarwal, Vivek; Lybeck, Nancy; Pham, Binh T.; ...

2015-06-04

This study presents the development of diagnostic and prognostic capabilities for active assets in nuclear power plants (NPPs). The research was performed under the Advanced Instrumentation, Information, and Control Technologies Pathway of the Light Water Reactor Sustainability Program. Idaho National Laboratory researched, developed, implemented, and demonstrated diagnostic and prognostic models for generator step-up transformers (GSUs). The Fleet-Wide Prognostic and Health Management (FW-PHM) Suite software developed by the Electric Power Research Institute was used to perform diagnosis and prognosis. As part of the research activity, Idaho National Laboratory implemented 22 GSU diagnostic models in the Asset Fault Signature Database and twomore » wellestablished GSU prognostic models for the paper winding insulation in the Remaining Useful Life Database of the FW-PHM Suite. The implemented models along with a simulated fault data stream were used to evaluate the diagnostic and prognostic capabilities of the FW-PHM Suite. Knowledge of the operating condition of plant asset gained from diagnosis and prognosis is critical for the safe, productive, and economical long-term operation of the current fleet of NPPs. This research addresses some of the gaps in the current state of technology development and enables effective application of diagnostics and prognostics to nuclear plant assets.« less

Bench-top validation testing of selected immunological and molecular Renibacterium salmoninarum diagnostic assays by comparison with quantitative bacteriological culture

USGS Publications Warehouse

Elliott, D.G.; Applegate, L.J.; Murray, A.L.; Purcell, M.K.; McKibben, C.L.

2013-01-01

No gold standard assay exhibiting error-free classification of results has been identified for detection of Renibacterium salmoninarum, the causative agent of salmonid bacterial kidney disease. Validation of diagnostic assays for R. salmoninarum has been hindered by its unique characteristics and biology, and difficulties in locating suitable populations of reference test animals. Infection status of fish in test populations is often unknown, and it is commonly assumed that the assay yielding the most positive results has the highest diagnostic accuracy, without consideration of misclassification of results. In this research, quantification of R. salmoninarum in samples by bacteriological culture provided a standardized measure of viable bacteria to evaluate analytical performance characteristics (sensitivity, specificity and repeatability) of non-culture assays in three matrices (phosphate-buffered saline, ovarian fluid and kidney tissue). Non-culture assays included polyclonal enzyme-linked immunosorbent assay (ELISA), direct smear fluorescent antibody technique (FAT), membrane-filtration FAT, nested polymerase chain reaction (nested PCR) and three real-time quantitative PCR assays. Injection challenge of specific pathogen-free Chinook salmon, Oncorhynchus tshawytscha (Walbaum), with R. salmoninarum was used to estimate diagnostic sensitivity and specificity. Results did not identify a single assay demonstrating the highest analytical and diagnostic performance characteristics, but revealed strengths and weaknesses of each test.

Continued Evaluation of Gear Condition Indicator Performance on Rotorcraft Fleet

NASA Technical Reports Server (NTRS)

Delgado, Irebert R.; Dempsey, Paula J.; Antolick, Lance J.; Wade, Daniel R.

2013-01-01

This paper details analyses of condition indicator performance for the helicopter nose gearbox within the U.S. Army's Condition-Based Maintenance Program. Ten nose gearbox data sets underwent two specific analyses. A mean condition indicator level analysis was performed where condition indicator performance was based on a 'batting average' measured before and after part replacement. Two specific condition indicators, Diagnostic Algorithm 1 and Sideband Index, were found to perform well for the data sets studied. A condition indicator versus gear wear analysis was also performed, where gear wear photographs and descriptions from Army tear-down analyses were categorized based on ANSI/AGMA 1010-E95 standards. Seven nose gearbox data sets were analyzed and correlated with condition indicators Diagnostic Algorithm 1 and Sideband Index. Both were found to be most responsive to gear wear cases of micropitting and spalling. Input pinion nose gear box condition indicators were found to be more responsive to part replacement during overhaul than their corresponding output gear nose gear box condition indicators.

Assessing technical performance in differential gene expression experiments with external spike-in RNA control ratio mixtures.

PubMed

Munro, Sarah A; Lund, Steven P; Pine, P Scott; Binder, Hans; Clevert, Djork-Arné; Conesa, Ana; Dopazo, Joaquin; Fasold, Mario; Hochreiter, Sepp; Hong, Huixiao; Jafari, Nadereh; Kreil, David P; Łabaj, Paweł P; Li, Sheng; Liao, Yang; Lin, Simon M; Meehan, Joseph; Mason, Christopher E; Santoyo-Lopez, Javier; Setterquist, Robert A; Shi, Leming; Shi, Wei; Smyth, Gordon K; Stralis-Pavese, Nancy; Su, Zhenqiang; Tong, Weida; Wang, Charles; Wang, Jian; Xu, Joshua; Ye, Zhan; Yang, Yong; Yu, Ying; Salit, Marc

2014-09-25

There is a critical need for standard approaches to assess, report and compare the technical performance of genome-scale differential gene expression experiments. Here we assess technical performance with a proposed standard 'dashboard' of metrics derived from analysis of external spike-in RNA control ratio mixtures. These control ratio mixtures with defined abundance ratios enable assessment of diagnostic performance of differentially expressed transcript lists, limit of detection of ratio (LODR) estimates and expression ratio variability and measurement bias. The performance metrics suite is applicable to analysis of a typical experiment, and here we also apply these metrics to evaluate technical performance among laboratories. An interlaboratory study using identical samples shared among 12 laboratories with three different measurement processes demonstrates generally consistent diagnostic power across 11 laboratories. Ratio measurement variability and bias are also comparable among laboratories for the same measurement process. We observe different biases for measurement processes using different mRNA-enrichment protocols.

Decomposition of the Mean Squared Error and NSE Performance Criteria: Implications for Improving Hydrological Modelling

NASA Technical Reports Server (NTRS)

Gupta, Hoshin V.; Kling, Harald; Yilmaz, Koray K.; Martinez-Baquero, Guillermo F.

2009-01-01

The mean squared error (MSE) and the related normalization, the Nash-Sutcliffe efficiency (NSE), are the two criteria most widely used for calibration and evaluation of hydrological models with observed data. Here, we present a diagnostically interesting decomposition of NSE (and hence MSE), which facilitates analysis of the relative importance of its different components in the context of hydrological modelling, and show how model calibration problems can arise due to interactions among these components. The analysis is illustrated by calibrating a simple conceptual precipitation-runoff model to daily data for a number of Austrian basins having a broad range of hydro-meteorological characteristics. Evaluation of the results clearly demonstrates the problems that can be associated with any calibration based on the NSE (or MSE) criterion. While we propose and test an alternative criterion that can help to reduce model calibration problems, the primary purpose of this study is not to present an improved measure of model performance. Instead, we seek to show that there are systematic problems inherent with any optimization based on formulations related to the MSE. The analysis and results have implications to the manner in which we calibrate and evaluate environmental models; we discuss these and suggest possible ways forward that may move us towards an improved and diagnostically meaningful approach to model performance evaluation and identification.

Diagnostic performance of semi-quantitative and quantitative stress CMR perfusion analysis: a meta-analysis.

PubMed

van Dijk, R; van Assen, M; Vliegenthart, R; de Bock, G H; van der Harst, P; Oudkerk, M

2017-11-27

Stress cardiovascular magnetic resonance (CMR) perfusion imaging is a promising modality for the evaluation of coronary artery disease (CAD) due to high spatial resolution and absence of radiation. Semi-quantitative and quantitative analysis of CMR perfusion are based on signal-intensity curves produced during the first-pass of gadolinium contrast. Multiple semi-quantitative and quantitative parameters have been introduced. Diagnostic performance of these parameters varies extensively among studies and standardized protocols are lacking. This study aims to determine the diagnostic accuracy of semi- quantitative and quantitative CMR perfusion parameters, compared to multiple reference standards. Pubmed, WebOfScience, and Embase were systematically searched using predefined criteria (3272 articles). A check for duplicates was performed (1967 articles). Eligibility and relevance of the articles was determined by two reviewers using pre-defined criteria. The primary data extraction was performed independently by two researchers with the use of a predefined template. Differences in extracted data were resolved by discussion between the two researchers. The quality of the included studies was assessed using the 'Quality Assessment of Diagnostic Accuracy Studies Tool' (QUADAS-2). True positives, false positives, true negatives, and false negatives were subtracted/calculated from the articles. The principal summary measures used to assess diagnostic accuracy were sensitivity, specificity, andarea under the receiver operating curve (AUC). Data was pooled according to analysis territory, reference standard and perfusion parameter. Twenty-two articles were eligible based on the predefined study eligibility criteria. The pooled diagnostic accuracy for segment-, territory- and patient-based analyses showed good diagnostic performance with sensitivity of 0.88, 0.82, and 0.83, specificity of 0.72, 0.83, and 0.76 and AUC of 0.90, 0.84, and 0.87, respectively. In per territory analysis our results show similar diagnostic accuracy comparing anatomical (AUC 0.86(0.83-0.89)) and functional reference standards (AUC 0.88(0.84-0.90)). Only the per territory analysis sensitivity did not show significant heterogeneity. None of the groups showed signs of publication bias. The clinical value of semi-quantitative and quantitative CMR perfusion analysis remains uncertain due to extensive inter-study heterogeneity and large differences in CMR perfusion acquisition protocols, reference standards, and methods of assessment of myocardial perfusion parameters. For wide spread implementation, standardization of CMR perfusion techniques is essential. CRD42016040176 .

Experimental Evaluation of a Structure-Based Connectionist Network for Fault Diagnosis of Helicopter Gearboxes

NASA Technical Reports Server (NTRS)

Jammu, V. B.; Danai, K.; Lewicki, D. G.

1998-01-01

This paper presents the experimental evaluation of the Structure-Based Connectionist Network (SBCN) fault diagnostic system introduced in the preceding article. For this vibration data from two different helicopter gearboxes: OH-58A and S-61, are used. A salient feature of SBCN is its reliance on the knowledge of the gearbox structure and the type of features obtained from processed vibration signals as a substitute to training. To formulate this knowledge, approximate vibration transfer models are developed for the two gearboxes and utilized to derive the connection weights representing the influence of component faults on vibration features. The validity of the structural influences is evaluated by comparing them with those obtained from experimental RMS values. These influences are also evaluated ba comparing them with the weights of a connectionist network trained though supervised learning. The results indicate general agreement between the modeled and experimentally obtained influences. The vibration data from the two gearboxes are also used to evaluate the performance of SBCN in fault diagnosis. The diagnostic results indicate that the SBCN is effective in directing the presence of faults and isolating them within gearbox subsystems based on structural influences, but its performance is not as good in isolating faulty components, mainly due to lack of appropriate vibration features.

Diagnostic accuracy of physical examination for anterior knee instability: a systematic review.

PubMed

Leblanc, Marie-Claude; Kowalczuk, Marcin; Andruszkiewicz, Nicole; Simunovic, Nicole; Farrokhyar, Forough; Turnbull, Travis Lee; Debski, Richard E; Ayeni, Olufemi R

2015-10-01

Determining diagnostic accuracy of Lachman, pivot shift and anterior drawer tests versus gold standard diagnosis (magnetic resonance imaging or arthroscopy) for anterior cruciate ligament (ACL) insufficiency cases. Secondarily, evaluating effects of: chronicity, partial rupture, awake versus anaesthetized evaluation. Searching MEDLINE, EMBASE and PubMed identified studies on diagnostic accuracy for ACL insufficiency. Studies identification and data extraction were performed in duplicate. Quality assessment used QUADAS tool, and statistical analyses were completed for pooled sensitivity and specificity. Eight studies were included. Given insufficient data, pooled analysis was only possible for sensitivity on Lachman and pivot shift test. During awake evaluation, sensitivity for the Lachman test was 89 % (95 % CI 0.76, 0.98) for all rupture types, 96 % (95 % CI 0.90, 1.00) for complete ruptures and 68 % (95 % CI 0.25, 0.98) for partial ruptures. For pivot shift in awake evaluation, results were 79 % (95 % CI 0.63, 0.91) for all rupture types, 86 % (95 % CI 0.68, 0.99) for complete ruptures and 67 % (95 % CI 0.47, 0.83) for partial ruptures. Decreased sensitivity of Lachman and pivot shift tests for partial rupture cases and for awake patients raised suspicions regarding the accuracy of these tests for diagnosis of ACL insufficiency. This may lead to further research aiming to improve the understanding of the true accuracy of these physical diagnostic tests and increase the reliability of clinical investigation for this pathology. IV.

Diagnostic performance of coronary computed tomography angiography versus exercise electrocardiography for coronary artery disease: a systematic review and meta-analysis

PubMed Central

Yin, Xinxin; Zheng, Wen; Ma, Jingjing; Hao, Panpan

2016-01-01

Background Both coronary computed tomography angiography (CCTA) and exercise electrocardiography (ExECG) are non-invasive testing methods for the evaluation of coronary artery disease (CAD). However, there was controversy on the diagnostic performance of these methods due to the limited data in each single study. Therefore, we performed a meta-analysis to address these issues. Methods We searched PubMed and Embase databases up to May 22, 2015. Two authors identified eligible studies, extracted data and accessed quality. Pooled estimation of sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), summary receiver-operating characteristic curve (SROC) and the area under curve (AUC) of CCTA and ExECG for the diagnosis of CAD were calculated using Stata, Meta-Disc and Review Manager statistical software. Results Seven articles were included. Pooled sensitivity of CCTA and ExECG were 0.98 [95% confidence intervals (CIs): 0.95–0.99] and 0.66 (95% CIs: 0.59–0.72); pooled specificity of CCTA and ExECG were 0.84 (95% CIs: 0.81–0.87) and 0.75 (95% CIs: 0.71–0.79); pooled DOR of CCTA and ExECG were 110.24 (95% CIs: 35.07–346.55) and 6.28 (95% CIs: 2.06–19.13); and AUC of CCTA and ExECG were 0.9950±0.0046 and 0.7727±0.0638, respectively. There is no heterogeneity caused by threshold effect in CCTA or ExECG analysis. The Deeks’ test showed no potential publication bias (P=0.17). Conclusions CCTA has better diagnostic performance than ExECG in the evaluation of CAD, which can provide a better solution for the clinical problem of the diagnosis for CAD. PMID:27499958

Gadolinium-enhanced digital subtraction angiography of hemodialysis fistulas: a diagnostic and therapeutic approach.

PubMed

Le Blanche, Alain-Ferdinand; Tassart, Marc; Deux, Jean-François; Rossert, Jérôme; Bigot, Jean-Michel; Boudghene, Frank

2002-10-01

The aim of our study was to evaluate the feasibility, safety, and potential role of the contrast agent gadoterate meglumine for digital subtraction angiography as a single diagnostic procedure or before percutaneous transluminal angioplasty of malfunctioning native dialysis fistulas. Over a 20-month period, 23 patients (15 women, eight men) with an age range of 42-87 years (mean, 63 years) having end-stage renal insufficiency and with recent hemodialysis fistula surgical placement underwent gadoterate-enhanced digital subtraction angiography with a digital 1024 x 1024 matrix. Opacification was performed on the forearm, arm, and chest with the patient in the supine position using an injection (retrograde, n = 14; anterograde, n = 8; arterial, n = 1) of gadoterate meglumine into the perianastomotic fistula segment at a rate of 3 mL/sec for a total volume ranging from 24 to 32 mL. Percutaneous transluminal angioplasty was performed in three patients and required an additional 8 mL per procedure. Examinations were compared using a 3-step confidence scale and a two-radiologist agreement (Cohen's kappa statistic) for diagnostic and opacification quality. Tolerability was evaluated on the basis of serum creatinine levels and the development of complications. No impairment of renal function was found in the 15 patients who were not treated with hemodialysis. Serum creatinine level change varied from -11.9% to 11.6%. All studies were of diagnostic quality. The presence of stenosis (n = 14) or thrombosis (n = 3) in arteriovenous fistulas was shown with good interobserver agreement (kappa = 0.71-0.80) in relation to opacification quality (kappa = 0.59-0.84). No pain, neurologic complications, or allergiclike reactions occurred. Three percutaneous transluminal angioplasty procedures (brachiocephalic, n = 2; radiocephalic, n = 1) were successfully performed. Gadoterate-enhanced digital subtraction angiography is an effective and safe method to assess causes of malfunction of hemodialysis fistulas. It can also be used to plan and perform percutaneous transluminal angioplasty.

Imaging techniques for evaluation of the uterine cavity and endometrium in premenopausal patients before minimally invasive surgery.

PubMed

Dueholm, Margit; Lundorf, Erik; Olesen, Frede

2002-06-01

A literature review compared the diagnostic effectiveness and accuracy of transvaginal sonography (TVS) hysterosonographic examination (HSE), hysteroscopy (HY), and magnetic resonance imaging (MRI) in abnormalities of the uterine cavity and endometrium in premenopausal patients referred to surgery and women with abnormal uterine bleeding. The studies varied much in terms of patient selection, number of observers, blinding and experience of observers, and definition of abnormality criteria. The diagnostic effectiveness of the techniques reviewed varied: TVS only reached intermediate quality levels as a diagnostic tool for exclusion of uterine cavity abnormalities and no data support that MRI, TVS, HY, or HSE may exclude hyperplasia without concomitant endometrial sampling. HY and HSE were equally effective and apparently outperformed TVS, especially for identification of polyps. However, all techniques carried a significant number of false positive results. MRI does not satisfy current diagnostic demands for detection of endometrial abnormalities, but it is sufficiently accurate for submucous myoma (SM) evaluation. TVS, HSE, and HY carry much observer variation as opposed to MRI. In experienced hands TVS should be a first choice modality, but its precision and consistency fall short of current needs and it should therefore be supplemented by other techniques. HSE or HY performed by experienced clinicians should be used as supplements to TVS for exclusion of polyps. MRI can be recommended as the first choice modality for exact evaluation of SM uterine in-growth before advanced minimal invasive treatment of myomas. Clinicians should be aware that modern imaging techniques may yield highly idiosyncratic results when used by inexperienced staff, and efforts should be made to reduce such observer variation. Obstetricians & Gynecologists, Family Physicians. After completion of this article, the reader will be able to describe the diagnostic strengths and weaknesses of the various diagnostic tests in the evaluation of abnormal uterine bleeding and to compare the accuracy of each test to the others.

In Vivo Detection of Choroidal Abnormalities Related to NF1: Feasibility and Comparison With Standard NIH Diagnostic Criteria in Pediatric Patients.

PubMed

Parrozzani, Raffaele; Clementi, Maurizio; Frizziero, Luisa; Miglionico, Giacomo; Perrini, Pierdavide; Cavarzeran, Fabiano; Kotsafti, Olympia; Comacchio, Francesco; Trevisson, Eva; Convento, Enrica; Fusetti, Stefano; Midena, Edoardo

2015-09-01

To evaluate the feasibility of near-infrared (NIR) imaging acquisition in a large sample of consecutive pediatric patients with neurofibromatosis type 1 (NF1), to evaluate the diagnostic performance of NF1-related choroidal abnormalities as a diagnostic criterion of the disease, and to compare this criterion with other standard National Institutes of Health (NIH) diagnostic criteria. A total of 140 consecutive pediatric patients (0-16 years old) affected by NF1 (at least two diagnostic criteria), 59 suspected (a single diagnostic criterion), and 42 healthy subjects (no diagnostic criterion) were consecutively included. Each patient underwent genetic, dermatologic, and ophthalmologic examination to evaluate the presence/absence of each NIH diagnostic criterion. The presence of NF1-related choroidal abnormalities was investigated using NIR confocal ophthalmoscopy. Two masked operators assessed Lisch nodules and NF1-related choroidal abnormalities. Neurofibromatosis type 1-related choroidal abnormalities were detected in 72 affected (60.5%) and 1 suspected (2.4%) child. No healthy subject had choroidal abnormalities. Feasibility rate of this sign was 82%. Sensitivity, specificity, and positive and negative predictive values of NF1-related choroidal abnormalities were 0.60, 0.97, 0.98, and 0.46, respectively. Compared with standard NIH criteria, the presence of NF1-related choroidal abnormalities was the third parameter for positive predictive value and the fourth for sensitivity, specificity, and negative predictive value. Compared with Lisch nodules, NF1-related choroidal abnormalities were characterized by higher specificity and positive predictive value. The interoperator agreement for Lisch nodules and NF1-related choroidal abnormalities was 0.67 (substantial) and 0.97 (almost perfect), respectively. The use of this sign moved one patient from the suspected to the affected group (0.5%). Neurofibromatosis type 1-related choroidal abnormalities represent a new diagnostic sign in NF1 children. The main advantage of this sign seems the theoretical possibility to anticipate NF1 diagnosis, whereas the main obstacle is the cooperation required by very young patients.

Computed tomography in the evaluation of penetrating neck trauma: a preliminary study.

PubMed

Gracias, V H; Reilly, P M; Philpott, J; Klein, W P; Lee, S Y; Singer, M; Schwab, C W

2001-11-01

Penetrating neck trauma has traditionally been evaluated by surgical exploration and/or invasive diagnostic studies. We hypothesized that computed tomography (CT), used as an early diagnostic tool to accurately determine trajectory, would direct or eliminate further studies or procedures in stable patients with penetrating neck trauma. Retrospective case series. Academic, urban, level I trauma center. Hemodynamically stable patients without hard signs of vascular injury or aerodigestive violation who had sustained penetrating trauma to the neck. Patients underwent a spiral CT as an initial diagnostic study after initial evaluation in the trauma bay. Further invasive studies were directed by CT findings. Number of invasive studies performed. Twenty-three patients were identified during the 30-month period. Nineteen patients sustained gunshot wounds; 3, shotgun wounds; and 1, a stab wound. One patient died of a cranial gunshot wound. Three isolated zone I, 1 isolated zone II, 9 isolated zone III, and 10 multiple neck zone trajectories were evaluated. Thirteen patients were identified by CT to have trajectories remote from vital structures and required no further evaluation. Ten patients underwent angiography. Only 2 underwent bronchoscopy and esophagoscopy. Four patients were discharged from the emergency department; 7 other patients were discharged within 24 hours. No adverse patient events occurred before, during, or after CT scan. Computed tomography in stable selected patients with penetrating neck trauma appears safe. Invasive studies can often be eliminated from the diagnostic algorithm when CT demonstrates trajectories remote from vital structures. As a result, efficient evaluation and early discharge from the trauma bay or emergency department can be realized. Further prospective study of CT scan after penetrating neck trauma is needed.

Intravoxel Incoherent Motion MR Imaging in the Differentiation of Benign and Malignant Sinonasal Lesions: Comparison with Conventional Diffusion-Weighted MR Imaging.

PubMed

Xiao, Z; Tang, Z; Qiang, J; Wang, S; Qian, W; Zhong, Y; Wang, R; Wang, J; Wu, L; Tang, W; Zhang, Z

2018-01-25

Intravoxel incoherent motion is a promising method for the differentiation of sinonasal lesions. This study aimed to evaluate the value of intravoxel incoherent motion in the differentiation of benign and malignant sinonasal lesions and to compare the diagnostic performance of intravoxel incoherent motion with that of conventional DWI. One hundred thirty-one patients with histologically proved solid sinonasal lesions (56 benign and 75 malignant) who underwent conventional DWI and intravoxel incoherent motion were recruited in this study. The diffusion coefficient ( D ), pseudodiffusion coefficient ( D *), and perfusion fraction ( f ) values derived from intravoxel incoherent motion and ADC values derived from conventional DWI were measured and compared between the 2 groups using the Student t test. Receiver operating characteristic curve analysis, logistic regression analysis, and 10-fold cross-validation were performed to evaluate the diagnostic performance of single-parametric and multiparametric models. The mean ADC and D values were significantly lower in malignant sinonasal lesions than in benign sinonasal lesions (both P < .001). The mean f value was higher in malignant lesions than in benign lesions ( P = .003). Multiparametric models can significantly improve the cross-validated areas under the curve for the differentiation of sinonasal lesions compared with single-parametric models (all corrected P < .05 except the D value). The model of D + f provided a better diagnostic performance than the ADC value (corrected P < .001). Intravoxel incoherent motion appears to be a more effective MR imaging technique than conventional DWI in the differentiation of benign and malignant sinonasal lesions. © 2018 by American Journal of Neuroradiology.

Evaluation of the Anterior Segment Angle-to-Angle Scan of Cirrus High-Definition Optical Coherence Tomography and Comparison With Gonioscopy and With the Visante OCT.

PubMed

Tun, Tin A; Baskaran, Mani; Tan, Shayne S; Perera, Shamira A; Aung, Tin; Husain, Rahat

2017-01-01

To evaluate the diagnostic performance of the anterior segment angle-to-angle scan of the Cirrus high-definition optical coherence tomography (HD-OCT) in detecting eyes with closed angles. All subjects underwent dark-room gonioscopy by an ophthalmologist. A technician performed anterior segment imaging with Cirrus (n = 202) and Visante OCT (n = 85) under dark-room conditions. All eyes were categorized by two masked graders as per number of closed quadrants. Each quadrant of anterior chamber angle was categorized as a closed angle if posterior trabecular meshwork could not be seen on gonioscopy or if there was any irido-corneal contact anterior to scleral spur in Cirrus and Visante images. An eye was graded as having a closed angle if two or more quadrants were closed. Agreement and area under the curve (AUC) were performed. There were 50 (24.8%) eyes with closed angles. The agreements of closed-angle diagnosis (by eye) between Cirrus HD-OCT and gonioscopy (k = 0.59; 95% confidence interval (CI) 0.45-0.72; AC1 = 0.76) and between Cirrus and Visante OCT (k = 0.65; 95% CI 0.48-0.82, AC1 = 0.77) were moderate. The AUC for diagnosing the eye with gonioscopic closed angle by Cirrus HD-OCT was good (AUC = 0.86; sensitivity = 83.33; specificity = 77.78). The diagnostic performance of Cirrus HD-OCT in detecting the eyes with closed angles was similar to that of Visante (AUC 0.87 vs. 0.9, respectively; P = 0.51). The anterior segment angle-to-angle scans of Cirrus HD-OCT demonstrated similar diagnostic performance as Visante in detecting gonioscopic closed angles. The agreement between Cirrus and gonioscopy for detecting eyes with closed angles was moderate.

Selection of examples in case-based computer-aided decision systems

PubMed Central

Mazurowski, Maciej A.; Zurada, Jacek M.; Tourassi, Georgia D.

2013-01-01

Case-based computer-aided decision (CB-CAD) systems rely on a database of previously stored, known examples when classifying new, incoming queries. Such systems can be particularly useful since they do not need retraining every time a new example is deposited in the case base. The adaptive nature of case-based systems is well suited to the current trend of continuously expanding digital databases in the medical domain. To maintain efficiency, however, such systems need sophisticated strategies to effectively manage the available evidence database. In this paper, we discuss the general problem of building an evidence database by selecting the most useful examples to store while satisfying existing storage requirements. We evaluate three intelligent techniques for this purpose: genetic algorithm-based selection, greedy selection and random mutation hill climbing. These techniques are compared to a random selection strategy used as the baseline. The study is performed with a previously presented CB-CAD system applied for false positive reduction in screening mammograms. The experimental evaluation shows that when the development goal is to maximize the system’s diagnostic performance, the intelligent techniques are able to reduce the size of the evidence database to 37% of the original database by eliminating superfluous and/or detrimental examples while at the same time significantly improving the CAD system’s performance. Furthermore, if the case-base size is a main concern, the total number of examples stored in the system can be reduced to only 2–4% of the original database without a decrease in the diagnostic performance. Comparison of the techniques shows that random mutation hill climbing provides the best balance between the diagnostic performance and computational efficiency when building the evidence database of the CB-CAD system. PMID:18854606

Operational evaluation of rapid diagnostic testing for Ebola Virus Disease in Guinean laboratories

PubMed Central

Aho, Josephine; Franklin, Kristyn; Likofata, Jacques; Kamgang, Jean Baptiste; Keita, Sakoba; Koivogui, Lamine; Magassouba, N’Faly; Martel, Lise D.; Dahourou, Anicet George

2017-01-01

Background Rapid Diagnostic Tests (RDTs) for Ebola Virus Disease (EVD) at the point of care have the potential to increase access and acceptability of EVD testing and the speed of patient isolation and secure burials for suspect cases. A pilot program for EVD RDTs in high risk areas of Guinea was introduced in October 2015. This paper presents concordance data between EVD RDTs and PCR testing in the field as well as an assessment of the acceptability, feasibility, and quality assurance of the RDT program. Methods and findings Concordance data were compiled from laboratory surveillance databases. The operational measures of the laboratory-based EVD RDT program were evaluated at all 34 sentinel sites in Guinea through: (1) a technical questionnaire filled by the lab technicians who performed the RDTs, (2) a checklist filled by the evaluator during the site visits, and (3) direct observation of the lab technicians performing the quality control test. Acceptability of the EVD RDT was good for technicians, patients, and families although many technicians (69.8%) expressed concern for their safety while performing the test. The feasibility of the program was good based on average technician knowledge scores (6.6 out of 8) but basic infrastructure, equipment, and supplies were lacking. There was much room for improvement in quality assurance of the program. Conclusions The implementation of new diagnostics in weak laboratory systems requires general training in quality assurance, biosafety and communication with patients in addition to specific training for the new test. Corresponding capacity building in terms of basic equipment and a long-term commitment to transfer supervision and quality improvement to national public health staff are necessary for successful implementation. PMID:29190713

Intensive training program for ultrasound diagnosis of adnexal masses: protocol and preliminary results.

PubMed

Alcázar, J L; Díaz, L; Flórez, P; Guerriero, S; Jurado, M

2013-08-01

To assess the feasibility of a specific training program for ultrasound diagnosis of adnexal masses. A 2-month intensive training program was developed. The program protocol consisted of a 1-day intensive theoretical course focused on clinical and sonographic issues related to adnexal masses and ovarian cancer, followed by a 4-week real-time ultrasound training program in a tertiary center (25-30 adnexal masses evaluated per month) and a final 4-week period for offline assessment of three-dimensional (3D) volumes from adnexal masses. In this final period, each trainee evaluated five sets of 100 3D volumes. 3D volumes contained gray-scale and power Doppler information, and the trainee was provided with clinical data for each case (patient age, menopausal status and reported symptoms). 3D volumes were obtained from surgically removed masses that had undergone histological diagnosis or from masses that had been followed up until resolution. After assessment of each set, the trainee's diagnostic performance was calculated (sensitivity and specificity) and each incorrectly classified mass was evaluated with the trainer. The objective was to achieve a sensitivity of > 95% and a specificity of > 90%. Learning curve cumulative summation (LC-CUSUM) graphs were plotted to assess the learning curve for the trainees. One trainer and two trainees with little experience in gynecological ultrasound (one gynecologist and one radiologist) participated in this study. LC-CUSUM graphs showed that competence was achieved after 170 or 185 examinations. The objectives for diagnostic performance were achieved after assessment of the second set of 3D volumes (200 cases) for each trainee. The proposed training program appears to be feasible. High diagnostic performance can be achieved after analysis of 200 cases and maintained thereafter. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.

Operational evaluation of rapid diagnostic testing for Ebola Virus Disease in Guinean laboratories.

PubMed

VanSteelandt, Amanda; Aho, Josephine; Franklin, Kristyn; Likofata, Jacques; Kamgang, Jean Baptiste; Keita, Sakoba; Koivogui, Lamine; Magassouba, N'Faly; Martel, Lise D; Dahourou, Anicet George

2017-01-01

Rapid Diagnostic Tests (RDTs) for Ebola Virus Disease (EVD) at the point of care have the potential to increase access and acceptability of EVD testing and the speed of patient isolation and secure burials for suspect cases. A pilot program for EVD RDTs in high risk areas of Guinea was introduced in October 2015. This paper presents concordance data between EVD RDTs and PCR testing in the field as well as an assessment of the acceptability, feasibility, and quality assurance of the RDT program. Concordance data were compiled from laboratory surveillance databases. The operational measures of the laboratory-based EVD RDT program were evaluated at all 34 sentinel sites in Guinea through: (1) a technical questionnaire filled by the lab technicians who performed the RDTs, (2) a checklist filled by the evaluator during the site visits, and (3) direct observation of the lab technicians performing the quality control test. Acceptability of the EVD RDT was good for technicians, patients, and families although many technicians (69.8%) expressed concern for their safety while performing the test. The feasibility of the program was good based on average technician knowledge scores (6.6 out of 8) but basic infrastructure, equipment, and supplies were lacking. There was much room for improvement in quality assurance of the program. The implementation of new diagnostics in weak laboratory systems requires general training in quality assurance, biosafety and communication with patients in addition to specific training for the new test. Corresponding capacity building in terms of basic equipment and a long-term commitment to transfer supervision and quality improvement to national public health staff are necessary for successful implementation.

Evaluation of the Performance of Five Diagnostic Tests for Fasciola hepatica Infection in Naturally Infected Cattle Using a Bayesian No Gold Standard Approach.

PubMed

Mazeri, Stella; Sargison, Neil; Kelly, Robert F; Bronsvoort, Barend M deC; Handel, Ian

2016-01-01

The clinical and economic importance of fasciolosis has been recognised for centuries, yet diagnostic tests available for cattle are far from perfect. Test evaluation has mainly been carried out using gold standard approaches or under experimental settings, the limitations of which are well known. In this study, a Bayesian no gold standard approach was used to estimate the diagnostic sensitivity and specificity of five tests for fasciolosis in cattle. These included detailed liver necropsy including gall bladder egg count, faecal egg counting, a commercially available copro-antigen ELISA, an in-house serum excretory/secretory antibody ELISA and routine abattoir liver inspection. In total 619 cattle slaughtered at one of Scotland's biggest abattoirs were sampled, during three sampling periods spanning summer 2013, winter 2014 and autumn 2014. Test sensitivities and specificities were estimated using an extension of the Hui Walter no gold standard model, where estimates were allowed to vary between seasons if tests were a priori believed to perform differently for any reason. The results of this analysis provide novel information on the performance of these tests in a naturally infected cattle population and at different times of the year where different levels of acute or chronic infection are expected. Accurate estimates of sensitivity and specificity will allow for routine abattoir liver inspection to be used as a tool for monitoring the epidemiology of F. hepatica as well as evaluating herd health planning. Furthermore, the results provide evidence to suggest that the copro-antigen ELISA does not cross-react with Calicophoron daubneyi rumen fluke parasites, while the serum antibody ELISA does.

The Effect of Study Design Biases on the Diagnostic Accuracy of Magnetic Resonance Imaging to Detect Silicone Breast Implant Ruptures: A Meta-Analysis

PubMed Central

Song, Jae W.; Kim, Hyungjin Myra; Bellfi, Lillian T.; Chung, Kevin C.

2010-01-01

Background All silicone breast implant recipients are recommended by the US Food and Drug Administration to undergo serial screening to detect implant rupture with magnetic resonance imaging (MRI). We performed a systematic review of the literature to assess the quality of diagnostic accuracy studies utilizing MRI or ultrasound to detect silicone breast implant rupture and conducted a meta-analysis to examine the effect of study design biases on the estimation of MRI diagnostic accuracy measures. Method Studies investigating the diagnostic accuracy of MRI and ultrasound in evaluating ruptured silicone breast implants were identified using MEDLINE, EMBASE, ISI Web of Science, and Cochrane library databases. Two reviewers independently screened potential studies for inclusion and extracted data. Study design biases were assessed using the QUADAS tool and the STARDS checklist. Meta-analyses estimated the influence of biases on diagnostic odds ratios. Results Among 1175 identified articles, 21 met the inclusion criteria. Most studies using MRI (n= 10 of 16) and ultrasound (n=10 of 13) examined symptomatic subjects. Meta-analyses revealed that MRI studies evaluating symptomatic subjects had 14-fold higher diagnostic accuracy estimates compared to studies using an asymptomatic sample (RDOR 13.8; 95% CI 1.83–104.6) and 2-fold higher diagnostic accuracy estimates compared to studies using a screening sample (RDOR 1.89; 95% CI 0.05–75.7). Conclusion Many of the published studies utilizing MRI or ultrasound to detect silicone breast implant rupture are flawed with methodological biases. These methodological shortcomings may result in overestimated MRI diagnostic accuracy measures and should be interpreted with caution when applying the data to a screening population. PMID:21364405

Evaluation of diagnostic criteria for panic attack using item response theory: findings from the National Comorbidity Survey in USA.

PubMed

Ietsugu, Tetsuji; Sukigara, Masune; Furukawa, Toshiaki A

2007-12-01

The dichotomous diagnostic systems such as the Diagnostic and Statistical Manual of Mental Disorders (DSM) and International Classification of Diseases (ICD) lose much important information concerning what each symptom can offer. This study explored the characteristics and performances of DSM-IV and ICD-10 diagnostic criteria items for panic attack using modern item response theory (IRT). The National Comorbidity Survey used the Composite International Diagnostic Interview to assess 14 DSM-IV and ICD-10 panic attack diagnostic criteria items in the general population in the USA. The dimensionality and measurement properties of these items were evaluated using dichotomous factor analysis and the two-parameter IRT model. A total of 1213 respondents reported at least one subsyndromal or syndromal panic attack in their lifetime. Factor analysis indicated that all items constitute a unidimensional construct. The two-parameter IRT model produced meaningful and interpretable results. Among items with high discrimination parameters, the difficulty parameter for "palpitation" was relatively low, while those for "choking," "fear of dying" and "paresthesia" were relatively high. Several items including "dry mouth" and "fear of losing control" had low discrimination parameters. The item characteristics of diagnostic criteria among help-seeking clinical populations may be different from those that we observed in the general population and deserve further examination. "Paresthesia," "choking" and "fear of dying" can be thought to be good indicators of severe panic attacks, while "palpitation" can discriminate well between cases and non-cases at low level of panic attack severity. Items such as "dry mouth" would contribute less to the discrimination.

Influence of region of interest size and ultrasound lesion size on the performance of 2D shear wave elastography (SWE) in solid breast masses.

PubMed

Skerl, K; Vinnicombe, S; Giannotti, E; Thomson, K; Evans, A

2015-12-01

To evaluate the influence of the region of interest (ROI) size and lesion diameter on the diagnostic performance of 2D shear wave elastography (SWE) of solid breast lesions. A study group of 206 consecutive patients (age range 21-92 years) with 210 solid breast lesions (70 benign, 140 malignant) who underwent core biopsy or surgical excision was evaluated. Lesions were divided into small (diameter <15 mm, n=112) and large lesions (diameter ≥15 mm, n=98). An ROI with a diameter of 1, 2, and 3 mm was positioned over the stiffest part of the lesion. The maximum elasticity (Emax), mean elasticity (Emean) and standard deviation (SD) for each ROI size were compared to the pathological outcome. Statistical analysis was undertaken using the chi-square test and receiver operating characteristic (ROC) analysis. The ROI size used has a significant impact on the performance of Emean and SD but not on Emax. Youden's indices show a correlation with the ROI size and lesion size: generally, the benign/malignant threshold is lower with increasing ROI size but higher with increasing lesion size. No single SWE parameter has superior performance. Lesion size and ROI size influence diagnostic performance. Copyright © 2015. Published by Elsevier Ltd.

Frequency and characteristics of melanomas missed at a pigmented lesion clinic: a registry-based study.

PubMed

Carli, Paolo; Nardini, Paolo; Crocetti, Emanuele; De Giorgi, Vincenzo; Giannotti, Benvenuto

2004-10-01

To ensure the removal of all melanomas at an early phase, a number of benign lesions are currently excised for diagnostic evaluation. Nevertheless, little is known about the frequency of melanomas missed (neither recognized nor excised for diagnostic verification) by early detection practices. This study aimed to investigate the diagnostic performance of a specialized pigmented lesion clinic (PLC) through linkage with a local cancer registry. In 1997, 1741 individuals resident in the area of Florence and Prato, Italy, the catchment area of the Tuscany Cancer Registry (RTT), were consecutively examined at a specialized PLC that has been running since 1992 at the Department of Dermatology of Florence. The outcomes of dermatological consultations retrieved from PLC case notes were compared with all the diagnoses of both in situ and invasive melanoma recorded by the RTT until 31 December 1999. The performance of the PLC in detecting cutaneous melanoma was evaluated in terms of sensitivity, specificity and predictive values, with the RTT data as the gold standard. In the population examined at the PLC, 15 newly incident melanomas, all histologically demonstrated, were recorded by the RTT. In 13 of the 15 cases, excision of the lesion had been recommended by PLC staff, while two melanomas, one in situ and one level II 0.60 mm thick invasive, were missed and were subsequently excised 586 and 824 days, respectively, after the first PLC examination. The clinical and dermoscopic features of the invasive lesion were in agreement with a 'featureless' melanoma, and lacked the well-established parameters of malignancy. A total of 67 benign pigmented skin lesions were excised for diagnostic evaluation. Thus the PLC showed a sensitivity in detecting cutaneous melanoma of 86.7% (95% confidence interval [CI] 85.1-88.3%), a specificity of 95.4% (95% CI 94.3-96.3%), a positive predictive value of 13.7% (95% CI 12.1-15.3%) and a negative predictive value of 99.9% (95% CI 99.7-100.0%). The ratio of melanomas to benign skin lesions excised was 1:5.1. In conclusion, specialized examination of pigmented skin lesions at the PLC offered good level of diagnostic performance, with an acceptable cost in terms of benign lesions removed and overall a low risk of missing melanomas.

Computer-aided diagnostic detection system of venous beading in retinal images

NASA Astrophysics Data System (ADS)

Yang, Ching-Wen; Ma, DyeJyun; Chao, ShuennChing; Wang, ChuinMu; Wen, Chia-Hsien; Lo, ChienShun; Chung, Pau-Choo; Chang, Chein-I.

2000-05-01

The detection of venous beading in retinal images provides an early sign of diabetic retinopathy and plays an important role as a preprocessing step in diagnosing ocular diseases. We present a computer-aided diagnostic system to automatically detect venous beading of blood vessels. It comprises of two modules, referred to as the blood vessel extraction module and the venus beading detection module. The former uses a bell-shaped Gaussian kernel with 12 azimuths to extract blood vessels while the latter applies a neural network-based shape cognitron to detect venous beading among the extracted blood vessels for diagnosis. Both modules are fully computer-automated. To evaluate the proposed system, 61 retinal images (32 beaded and 29 normal images) are used for performance evaluation.

Diagnostic accuracy of 256-row multidetector CT coronary angiography with prospective ECG-gating combined with fourth-generation iterative reconstruction algorithm in the assessment of coronary artery bypass: evaluation of dose reduction and image quality.

PubMed

Ippolito, Davide; Fior, Davide; Franzesi, Cammillo Talei; Riva, Luca; Casiraghi, Alessandra; Sironi, Sandro

2017-12-01

Effective radiation dose in coronary CT angiography (CTCA) for coronary artery bypass graft (CABG) evaluation is remarkably high because of long scan lengths. Prospective electrocardiographic gating with iterative reconstruction can reduce effective radiation dose. To evaluate the diagnostic performance of low-kV CT angiography protocol with prospective ecg-gating technique and iterative reconstruction (IR) algorithm in follow-up of CABG patients compared with standard retrospective protocol. Seventy-four non-obese patients with known coronary disease treated with artery bypass grafting were prospectively enrolled. All the patients underwent 256 MDCT (Brilliance iCT, Philips) CTCA using low-dose protocol (100 kV; 800 mAs; rotation time: 0.275 s) combined with prospective ECG-triggering acquisition and fourth-generation IR technique (iDose 4 ; Philips); all the lengths of the bypass graft were included in the evaluation. A control group of 42 similar patients was evaluated with a standard retrospective ECG-gated CTCA (100 kV; 800 mAs).On both CT examinations, ROIs were placed to calculate standard deviation of pixel values and intra-vessel density. Diagnostic quality was also evaluated using a 4-point quality scale. Despite the statistically significant reduction of radiation dose evaluated with DLP (study group mean DLP: 274 mGy cm; control group mean DLP: 1224 mGy cm; P value < 0.001). No statistical differences were found between PGA group and RGH group regarding intra-vessel density absolute values and SNR. Qualitative analysis, evaluated by two radiologists in "double blind", did not reveal any significant difference in diagnostic quality of the two groups. The development of high-speed MDCT scans combined with modern IR allows an accurate evaluation of CABG with prospective ECG-gating protocols in a single breath hold, obtaining a significant reduction in radiation dose.

Diagnostic performance of a rapid in-clinic test for the detection of Canine Parvovirus under different storage conditions and vaccination status.

PubMed

Kantere, Maria C; Athanasiou, Labrini V; Spyrou, Vassiliki; Kyriakis, Constantinos S; Kontos, Vassilios; Chatzopoulos, Dimitrios C; Tsokana, Constantina N; Billinis, Charalambos

2015-04-01

Canine parvovirus (CPV) is one of the most common causes of acute haemorrhagic enteritis in young dogs, while clinical diagnosis is often indecisive. The aim of our study was to evaluate the diagnostic accuracy of an in-clinic rapid test in the detection of CPV infection in dogs. To this end, we compared the Rapid Diagnostic Kit of Canine Parvovirus, Coronavirus and Rotavirus antigen (Quicking(®)) to PCR, which is considered as the most reliable diagnostic method. A total of 78 duplicated faecal samples were collected from diarrhoeic dogs. Vaccination history within a month prior to the onset of diarrhoea was reported for 12 of the sampled dogs. The rapid diagnostic test was performed in 23 of the faecal samples directly, while the rest were placed into a sterile cotton tipped swab suitable for collection and transportation of viruses (Sigma Σ-VCM(®)) and stored at -20 °C. The sensitivity of the Quicking rapid diagnostic test compared to PCR in the total number of samples, in samples from non-vaccinated dogs and in samples tested directly after collection were 22.22% (95% CI: 13.27-33.57%), 26.67% (95% CI: 16.08-39.66%) and 76.47% (95% CI: 50.10-93.04%) respectively, while the specificity of the test was 100% in any case. In conclusion, negative results do not exclude parvoenteritis from the differential diagnosis, especially in dogs with early vaccination history, but a positive result almost certainly indicates CPV infection. An improved sensitivity may be expected when the test is performed immediately. Copyright © 2015 Elsevier B.V. All rights reserved.

Diagnostic Ability of Wide-field Retinal Nerve Fiber Layer Maps Using Swept-Source Optical Coherence Tomography for Detection of Preperimetric and Early Perimetric Glaucoma.

PubMed

Lee, Won June; Na, Kyeong Ik; Kim, Young Kook; Jeoung, Jin Wook; Park, Ki Ho

2017-06-01

To evaluate the diagnostic ability of wide-field retinal nerve fiber layer (RNFL) maps with swept-source optical coherence tomography (SS-OCT) for detection of preperimetric (PPG) and early perimetric glaucoma (EG). One hundred eighty-four eyes, including 67 healthy eyes, 43 eyes with PPG, and 74 eyes with EG, were analyzed. Patients underwent a comprehensive ocular examination including red-free RNFL photography, visual field testing and wide-field SS-OCT scanning (DRI-OCT-1 Atlantis; Topcon, Tokyo, Japan). SS-OCT provides a wide-field RNFL thickness map and a SuperPixel map, which are composed of the RNFL deviation map of the peripapillary area and the deviation map of the composition of the ganglion cell layer with the inner plexiform layer and RNFL (GC-IPL+RNFL) in the macular area. The ability to discriminate PPG and EG from healthy eyes was assessed using sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) for all parameters and criteria provided by the wide-field SS-OCT scan. The wide-field RNFL thickness map using SS-OCT showed the highest sensitivity of PPG-diagnostic and EG-diagnostic performance compared with the other SS-OCT criteria based on the internal normative base (93.0 and 97.3%, respectively). Among the SS-OCT continuous parameters, the RFNL thickness of the 7 clock-hour, inferior and inferotemporal macular ganglion cell analyses showed the largest AUC of PPG-diagnostic and EG-diagnostic performance (AUC=0.809 to 0.865). The wide-field RNFL thickness map using SS-OCT performed well in distinguishing eyes with PPG and EG from healthy eyes. In the clinical setting, wide-field RNFL maps of SS-OCT can be useful tools for detection of early-stage glaucoma.

Xpert MTB/RIF Assay for Pulmonary Tuberculosis and Rifampicin Resistance in Children: a Meta-Analysis.

PubMed

Wang, X W; Pappoe, F; Huang, Y; Cheng, X W; Xu, D F; Wang, H; Xu, Y H

2015-01-01

The Xpert MTB/RIF assay has been recommended by WHO to replace conventional microscopy, culture, and drug resistance tests. It simultaneously detects both Mycobacterium tuberculosis infection (TB) and resistance to rifampicin (RIF) within two hours. The objective was to review the available research studies on the accuracy of the Xpert MTB/RIF assay for diagnosing pulmonary TB and RIF-resistance in children. A comprehensive search of Pubmed and Embase was performed up to October 28, 2014. We identified published articles estimating the diagnostic accuracy of the Xpert MTB/RIF assay in children with or without HIV using culture or culture plus clinical TB as standard reference. QUADAS-2 tool was used to evaluate the quality of the studies. A summary estimation for sensitivity, specificity, diagnostic odds ratios (DOR), and the area under the summary ROC curve (AUC) was performed. Meta-analysis was used to establish the overall accuracy. 11 diagnostic studies with 3801 patients were included in the systematic review. The overall analysis revealed a moderate sensitivity and high specificity of 65% (95% CI: 61 - 69%) and 99% (95% CI: 98 - 99%), respectively, and a pooled diagnostic odds ratio of 164.09 (95% CI: 111.89 - 240.64). The AUC value was found to be 0.94. The pooled sensitivity and specificity for paediatric rifampicin resistance were 94.0% (95% CI: 80.0 - 93.0%) and 99.0% (95% CI: 95.0 - 98.0%), respectively. Hence, the Xpert MTB/RIF assay has good diagnostic and rifampicin performance for paediatric pulmonary tuberculosis. The Xpert MTB/RIF is sensitive and specific for diagnosing paediatric pulmonary TB. It is also effective in detecting rifamnicin resistance. It can, therefore, be used as an initial diagnostic tool.

Computer-aided US diagnosis of breast lesions by using cell-based contour grouping.

PubMed

Cheng, Jie-Zhi; Chou, Yi-Hong; Huang, Chiun-Sheng; Chang, Yeun-Chung; Tiu, Chui-Mei; Chen, Kuei-Wu; Chen, Chung-Ming

2010-06-01

To develop a computer-aided diagnostic algorithm with automatic boundary delineation for differential diagnosis of benign and malignant breast lesions at ultrasonography (US) and investigate the effect of boundary quality on the performance of a computer-aided diagnostic algorithm. This was an institutional review board-approved retrospective study with waiver of informed consent. A cell-based contour grouping (CBCG) segmentation algorithm was used to delineate the lesion boundaries automatically. Seven morphologic features were extracted. The classifier was a logistic regression function. Five hundred twenty breast US scans were obtained from 520 subjects (age range, 15-89 years), including 275 benign (mean size, 15 mm; range, 5-35 mm) and 245 malignant (mean size, 18 mm; range, 8-29 mm) lesions. The newly developed computer-aided diagnostic algorithm was evaluated on the basis of boundary quality and differentiation performance. The segmentation algorithms and features in two conventional computer-aided diagnostic algorithms were used for comparative study. The CBCG-generated boundaries were shown to be comparable with the manually delineated boundaries. The area under the receiver operating characteristic curve (AUC) and differentiation accuracy were 0.968 +/- 0.010 and 93.1% +/- 0.7, respectively, for all 520 breast lesions. At the 5% significance level, the newly developed algorithm was shown to be superior to the use of the boundaries and features of the two conventional computer-aided diagnostic algorithms in terms of AUC (0.974 +/- 0.007 versus 0.890 +/- 0.008 and 0.788 +/- 0.024, respectively). The newly developed computer-aided diagnostic algorithm that used a CBCG segmentation method to measure boundaries achieved a high differentiation performance. Copyright RSNA, 2010

Coronary CT angiography using 64 detector rows: methods and design of the multi-centre trial CORE-64.

PubMed

Miller, Julie M; Dewey, Marc; Vavere, Andrea L; Rochitte, Carlos E; Niinuma, Hiroyuki; Arbab-Zadeh, Armin; Paul, Narinder; Hoe, John; de Roos, Albert; Yoshioka, Kunihiro; Lemos, Pedro A; Bush, David E; Lardo, Albert C; Texter, John; Brinker, Jeffery; Cox, Christopher; Clouse, Melvin E; Lima, João A C

2009-04-01

Multislice computed tomography (MSCT) for the noninvasive detection of coronary artery stenoses is a promising candidate for widespread clinical application because of its non-invasive nature and high sensitivity and negative predictive value as found in several previous studies using 16 to 64 simultaneous detector rows. A multi-centre study of CT coronary angiography using 16 simultaneous detector rows has shown that 16-slice CT is limited by a high number of nondiagnostic cases and a high false-positive rate. A recent meta-analysis indicated a significant interaction between the size of the study sample and the diagnostic odds ratios suggestive of small study bias, highlighting the importance of evaluating MSCT using 64 simultaneous detector rows in a multi-centre approach with a larger sample size. In this manuscript we detail the objectives and methods of the prospective "CORE-64" trial ("Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography using 64 Detectors"). This multi-centre trial was unique in that it assessed the diagnostic performance of 64-slice CT coronary angiography in nine centres worldwide in comparison to conventional coronary angiography. In conclusion, the multi-centre, multi-institutional and multi-continental trial CORE-64 has great potential to ultimately assess the per-patient diagnostic performance of coronary CT angiography using 64 simultaneous detector rows.

Consequences of radiopharmaceutical extravasation and therapeutic interventions: a systematic review.

PubMed

van der Pol, Jochem; Vöö, Stefan; Bucerius, Jan; Mottaghy, Felix M

2017-07-01

Radiopharmaceutical extravasation can potentially lead to severe soft tissue damage, but little is known about incidence, medical consequences, possible interventions, and effectiveness of these. The aims of this study are to estimate the incidence of extravasation of diagnostic and therapeutic radiopharmaceuticals, to evaluate medical consequences, and to evaluate medical treatment applied subsequently to those incidents. A sensitive and elaborate literature search was performed in Embase and PubMed using the keywords "misadministration", "extravasation", "paravascular infiltration", combined with "tracer", "radionuclide", "radiopharmaceutical", and a list of keywords referring to clinically used tracers (i.e. "Technetium-99m", "Yttrium-90"). Reported data on radiopharmaceutical extravasation and applied interventions was extracted and summarised. Thirty-seven publications reported 3016 cases of diagnostic radiopharmaceutical extravasation, of which three cases reported symptoms after extravasation. Eight publications reported 10 cases of therapeutic tracer extravasation. The most severe symptom was ulceration. Thirty-four different intervention and prevention strategies were performed or proposed in literature. Extravasation of diagnostic radiopharmaceuticals is common. 99m Tc, 123 I, 18 F, and 68 Ga labelled tracers do not require specific intervention. Extravasation of therapeutic radiopharmaceuticals can give severe soft tissue lesions. Although not evidence based, surgical intervention should be considered. Furthermore, dispersive intervention, dosimetry and follow up is advised. Pharmaceutical intervention has no place yet in the immediate care of radiopharmaceutical extravasation.

Automated Breast Ultrasonography (ABUS) in the Screening and Diagnostic Setting: Indications and Practical Use.

PubMed

Rella, Rossella; Belli, Paolo; Giuliani, Michela; Bufi, Enida; Carlino, Giorgio; Rinaldi, Pierluigi; Manfredi, Riccardo

2018-03-16

Automated breast ultrasonography (ABUS) is a new imaging technology for automatic breast scanning through ultrasound. It was first developed to overcome the limitation of operator dependency and lack of standardization and reproducibility of handheld ultrasound. ABUS provides a three-dimensional representation of breast tissue and allows images reformatting in three planes, and the generated coronal plane has been suggested to improve diagnostic accuracy. This technique has been first used in the screening setting to improve breast cancer detection, especially in mammographically dense breasts. In recent years, numerous studies also evaluated its use in the diagnostic setting: they showed its suitability for breast cancer staging, evaluation of tumor response to neoadjuvant chemotherapy, and second-look ultrasound after magnetic resonance imaging. The purpose of this article is to provide a comprehensive review of the current body of literature about the clinical performance of ABUS, summarize available evidence, and identify gaps in knowledge for future research. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Quantitative assessment of tumour extraction from dermoscopy images and evaluation of computer-based extraction methods for an automatic melanoma diagnostic system.

PubMed

Iyatomi, Hitoshi; Oka, Hiroshi; Saito, Masataka; Miyake, Ayako; Kimoto, Masayuki; Yamagami, Jun; Kobayashi, Seiichiro; Tanikawa, Akiko; Hagiwara, Masafumi; Ogawa, Koichi; Argenziano, Giuseppe; Soyer, H Peter; Tanaka, Masaru

2006-04-01

The aims of this study were to provide a quantitative assessment of the tumour area extracted by dermatologists and to evaluate computer-based methods from dermoscopy images for refining a computer-based melanoma diagnostic system. Dermoscopic images of 188 Clark naevi, 56 Reed naevi and 75 melanomas were examined. Five dermatologists manually drew the border of each lesion with a tablet computer. The inter-observer variability was evaluated and the standard tumour area (STA) for each dermoscopy image was defined. Manual extractions by 10 non-medical individuals and by two computer-based methods were evaluated with STA-based assessment criteria: precision and recall. Our new computer-based method introduced the region-growing approach in order to yield results close to those obtained by dermatologists. The effectiveness of our extraction method with regard to diagnostic accuracy was evaluated. Two linear classifiers were built using the results of conventional and new computer-based tumour area extraction methods. The final diagnostic accuracy was evaluated by drawing the receiver operating curve (ROC) of each classifier, and the area under each ROC was evaluated. The standard deviations of the tumour area extracted by five dermatologists and 10 non-medical individuals were 8.9% and 10.7%, respectively. After assessment of the extraction results by dermatologists, the STA was defined as the area that was selected by more than two dermatologists. Dermatologists selected the melanoma area with statistically smaller divergence than that of Clark naevus or Reed naevus (P = 0.05). By contrast, non-medical individuals did not show this difference. Our new computer-based extraction algorithm showed superior performance (precision, 94.1%; recall, 95.3%) to the conventional thresholding method (precision, 99.5%; recall, 87.6%). These results indicate that our new algorithm extracted a tumour area close to that obtained by dermatologists and, in particular, the border part of the tumour was adequately extracted. With this refinement, the area under the ROC increased from 0.795 to 0.875 and the diagnostic accuracy showed an increase of approximately 20% in specificity when the sensitivity was 80%. It can be concluded that our computer-based tumour extraction algorithm extracted almost the same area as that obtained by dermatologists and provided improved computer-based diagnostic accuracy.

Early hearing detection and intervention: 2010 CODEPEH recommendation.

PubMed

Trinidad-Ramos, Germán; de Aguilar, Valentín Alzina; Jaudenes-Casaubón, Carmen; Núñez-Batalla, Faustino; Sequí-Canet, José Miguel

2010-01-01

Newborn hearing screening is currently performed routinely in many regional health-care systems in Spain. Despite the remarkable expansion in newborn hearing screening since 2000, its feasibility and the benefits of early identification and intervention, many major challenges still remain. In this article, the Committee for the Early Detection of Hearing Loss (Comisión para la Detección Precoz de la Hipoacusia, CODEPEH) updates the recommendations that are considered important for the future development of early hearing detection and intervention (EDHI) systems in the following points: 1. Screening protocols: Separate protocols are recommended for NICU (Neonatal Intensive Care Units) and well-infant nurseries. 2. Diagnostic audiology evaluation. Professionals with skills and expertise in evaluating newborn and young infants should provide diagnosis, selection and fitting of amplification devices. 3. Medical evaluation. Risk factors for congenital and acquired hearing loss have been combined in a single list rather than grouped by time of onset. A stepwise diagnostic paradigm is diagnostically more efficient and cost-effective than a simultaneous testing approach. 4. Early intervention and surveillance. All individuals providing services to infants with hearing loss should have specialized training and expertise in the development of audition, speech and language. Regular surveillance should be performed on developmental milestones, auditory skills, parental concerns, and middle ear status. 5. Quality control. Data management as part of an integrated system is important to monitor and improve the quality of EDHI services. 2009 Elsevier España, S.L. All rights reserved.

ARM Data-Oriented Metrics and Diagnostics Package for Climate Model Evaluation Value-Added Product

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Chengzhu; Xie, Shaocheng

A Python-based metrics and diagnostics package is currently being developed by the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Infrastructure Team at Lawrence Livermore National Laboratory (LLNL) to facilitate the use of long-term, high-frequency measurements from the ARM Facility in evaluating the regional climate simulation of clouds, radiation, and precipitation. This metrics and diagnostics package computes climatological means of targeted climate model simulation and generates tables and plots for comparing the model simulation with ARM observational data. The Coupled Model Intercomparison Project (CMIP) model data sets are also included in the package to enable model intercomparison as demonstratedmore » in Zhang et al. (2017). The mean of the CMIP model can serve as a reference for individual models. Basic performance metrics are computed to measure the accuracy of mean state and variability of climate models. The evaluated physical quantities include cloud fraction, temperature, relative humidity, cloud liquid water path, total column water vapor, precipitation, sensible and latent heat fluxes, and radiative fluxes, with plan to extend to more fields, such as aerosol and microphysics properties. Process-oriented diagnostics focusing on individual cloud- and precipitation-related phenomena are also being developed for the evaluation and development of specific model physical parameterizations. The version 1.0 package is designed based on data collected at ARM’s Southern Great Plains (SGP) Research Facility, with the plan to extend to other ARM sites. The metrics and diagnostics package is currently built upon standard Python libraries and additional Python packages developed by DOE (such as CDMS and CDAT). The ARM metrics and diagnostic package is available publicly with the hope that it can serve as an easy entry point for climate modelers to compare their models with ARM data. In this report, we first present the input data, which constitutes the core content of the metrics and diagnostics package in section 2, and a user's guide documenting the workflow/structure of the version 1.0 codes, and including step-by-step instruction for running the package in section 3.« less

SvSXP: a Strongylus vulgaris antigen with potential for prepatent diagnosis.

PubMed

Andersen, Ulla V; Howe, Daniel K; Dangoudoubiyam, Sriveny; Toft, Nils; Reinemeyer, Craig R; Lyons, Eugene T; Olsen, Susanne N; Monrad, Jesper; Nejsum, Peter; Nielsen, Martin K

2013-04-04

Strongyle parasites are ubiquitous in grazing horses. Strongylus vulgaris, the most pathogenic of the large strongyles, is known for its extensive migration in the mesenteric arterial system. The lifecycle of S. vulgaris is characterised by a long prepatent period where the migrating larvae are virtually undetectable as there currently is no test available for diagnosing prepatent S. vulgaris infection. Presence of S. vulgaris larvae in the arterial system causes endarteritis and thrombosis with a risk of non-strangulating intestinal infarctions. Emergence of anthelmintic resistance among cyathostomins has led to recommendations of reduced treatment intensity by targeting horses that exceed a predetermined strongyle faecal egg count threshold. One study suggests an apparent increase in prevalence of S. vulgaris on farms where reduced anthelmintic treatment intensity has been implemented. These issues highlight the need for an accurate and reliable assay for diagnosing prepatent S. vulgaris infection. Immunoscreening of a larval S. vulgaris cDNA library using hyperimmune serum raised against S. vulgaris excretory/secretory antigens was performed to identify potential diagnostic antigens. Immunoreactive clones were sequenced, one potential antigen was characterised, expressed as a recombinant protein, initially evaluated by western blot (WB) analysis, the diagnostic potential of the IgG subclasses was evaluated by ELISA, and the diagnostic accuracy evaluated using serum from 102 horses with known S. vulgaris infection status. The clone expressing the potential antigen encoded a S. vulgaris SXP/RAL2 homologue. The recombinant protein, rSvSXP, was shown to be a potential diagnostic antigen by WB analysis, and a target of serum IgGa, IgG(T) and total IgG in naturally infected horses, with IgG(T) antibodies being the most reliable indicator of S. vulgaris infection in horses. Evaluation of diagnostic accuracy of the ELISA resulted in a sensitivity of 73.3%, a specificity of 81.0%, a diagnostic odds ratio of 11.69; a positive likelihood ratio (LR) of 3.85 and a negative LR was 0.33. The area under the ROC curve was 0.820. IgG(T) antibodies to recombinant SvSXP show potential for use as an antigen for prepatent diagnosis of migrating stages of S. vulgaris with moderate to good diagnostic accuracy.

Pulmonary Infiltrates in Immunosuppressed Patients: Analysis of a Diagnostic Protocol

PubMed Central

Danés, Cristina; González-Martín, Julián; Pumarola, Tomàs; Rañó, Ana; Benito, Natividad; Torres, Antoni; Moreno, Asunción; Rovira, Montserrat; Puig de la Bellacasa, Jorge

2002-01-01

A diagnostic protocol was started to study the etiology of pulmonary infiltrates in immunosuppressed patients. The diagnostic yields of the different techniques were analyzed, with special emphasis on the importance of the sample quality and the role of rapid techniques in the diagnostic strategy. In total, 241 patients with newly developed pulmonary infiltrates within a period of 19 months were included. Noninvasive or invasive evaluation was performed according to the characteristics of the infiltrates. Diagnosis was achieved in 202 patients (84%); 173 patients (72%) had pneumonia, and specific etiologic agents were found in 114 (66%). Bronchoaspirate and bronchoalveolar lavage showed the highest yields, either on global analysis (23 of 35 specimens [66%] and 70 of 134 specimens [52%], respectively) or on analysis of each type of pneumonia. A tendency toward better results with optimal-quality samples was observed, and a statistically significant difference was found in sputum bacterial culture. Rapid diagnostic tests yielded results in 71 of 114 (62.2%) diagnoses of etiological pneumonia. PMID:12037077

IDENTIFICATION AND EVALUATION OF CHARACTERISTICS OF KINDERGARTEN CHILDREN THAT FORETELL EARLY LEARNING PROBLEMS. FINAL REPORT.

ERIC Educational Resources Information Center

REECE, WILLIAM K.

TO EVALUATE THE EFFECTIVENESS OF A KINDERGARTEN PROGRAM OF SPECIFIC TRAINING RELATED TO MOTOR, SENSORY, AND PERCEPTUAL (M-S-P) PERFORMANCE, AN INSTRUMENT WAS DEVISED TO MEASURE THE M-S-P NEEDS AND STRENGTHS OF INDIVIDUAL PUPILS. RESEARCH WAS CONDUCTED TO TEST THE DIAGNOSTIC AND PREDICTIVE POTENTIALS OF THE M-S-P INSTRUMENT AND TO ASCERTAIN THE…

The after breakfast 50-g, 1-hour glucose challenge test in urban Mexican pregnant women: its sensitivity and specificity evaluated by three diagnostic criteria for gestational diabetes mellitus.

PubMed

Espinosa de los Monteros, A; Parra, A; Hidalgo, R; Zambrana, M

1999-04-01

To study the sensitivity and specificity of the 50-g, 1-hour gestational glucose challenge test performed 1 to 2 hours after a non-standardized home breakfast in urban Mexican women by using three different gestational diabetes mellitus diagnostic criteria. Four hundred and forty-five consecutive women of 24-28 weeks gestation were studied. The glucose challenge test was performed in the fed state and a week later a fasting 100-g, 3-hours oral glucose tolerance test was carried out in all of them. Duplicate serum glucose concentrations were determined by a glucose-oxidase method. Sensitivity and specificity were calculated using three different diagnostic criteria for gestational diabetes mellitus. The glucose challenge test performed as indicated, with a cutoff of 7.8 mmol/L, had 88-89% sensitivity and 85-87% specificity when using as diagnostic criteria those proposed by the National Diabetes Data Group and by Carpenter & Coustan; by using Sacks et al. criteria, the values were 82% and 88%, respectively. Considering only pregnant women > or = 25 years of age, the sensitivity increased to 92% with the National Diabetes Data Group criteria. Pregnant women < 25 years of age had significantly lower blood glucose values than those with age > or = 25 years during the glucose tolerance test. For the general group the sensitivity of the glucose challenge test performed 1 to 2 hours after breakfast was similar, based on the National Diabetes Data Group and the Carpenter & Coustan's diagnostic criteria for gestational diabetes mellitus. However, when pregnant women > or = 25 years of age were considered, the use of the former criteria yielded a slightly better sensitivity.

Neural Network Analysis of Different Segmentation Strategies of Nerve Fiber Layer Assessment for Glaucoma Diagnosis.

PubMed

Larrosa, Jose M; Polo, Vicente; Ferreras, Antonio; García-Martín, Elena; Calvo, Pilar; Pablo, Luis E

2015-12-01

To compare the diagnostic performance of different segmentations of the nerve fiber layer (NFL) thickness measurements using an artificial neural network and to define the optimal number of sectors with best diagnostic ability for glaucoma diagnosis. A total of 117 glaucoma patients and 123 normal subjects were included in the study. NFL thickness measurements were performed using the Spectralis-OCT (Heidelberg Engineering) to obtain the NFL thickness average; measurements from 2 semicircles, 4 quadrants, and 6, 8, 12, 16, 24, 32, and 64 sectors; and 768 uniformly divided locations around the peripapillary NFL. An artificial neural network evaluation was performed to compare the influence of sector analysis on the diagnostic performance of optical coherence tomography. Receiver operating characteristic curves were used to compare the diagnostic ability of the different segmentation analyses. The 6 sectors divided by the horizontal division of the nasal and temporal quadrants were better than the 6 sectors divided by the vertical line through the superior and inferior quadrants [areas under curve, 0.778; 95% confidence interval (CI), 0.720-0.829 and 0.814; 95% CI, 0.759-0.861, respectively]. In the case of quadrants, clock quadrants (area under curve 0.770; 95% CI, 0.712-0.822) were better than the ISNT (inferior-superior-nasal-temporal) quadrants (area under curve, 0.770; 95% CI, 0.712-0.822; P=0.003). The first segmentation strategy that improved the diagnostic value of 4 ISNT quadrants was the 12-sector analysis (area under curve, 0.845; 95% CI, 0.793-0.889; P=0.001). The 2 best candidate strategies for the OCT report were the 12-sector analysis and the 4 planimetric quadrant (alternatively, the 4 clock quadrants) analysis.

Basophil activation test discriminates between allergy and tolerance in peanut-sensitized children.

PubMed

Santos, Alexandra F; Douiri, Abdel; Bécares, Natalia; Wu, Shih-Ying; Stephens, Alick; Radulovic, Suzana; Chan, Susan M H; Fox, Adam T; Du Toit, George; Turcanu, Victor; Lack, Gideon

2014-09-01

Most of the peanut-sensitized children do not have clinical peanut allergy. In equivocal cases, oral food challenges (OFCs) are required. However, OFCs are laborious and not without risk; thus, a test that could accurately diagnose peanut allergy and reduce the need for OFCs is desirable. To assess the performance of basophil activation test (BAT) as a diagnostic marker for peanut allergy. Peanut-allergic (n = 43), peanut-sensitized but tolerant (n = 36) and non-peanut-sensitized nonallergic (n = 25) children underwent skin prick test (SPT) and specific IgE (sIgE) to peanut and its components. BAT was performed using flow cytometry, and its diagnostic performance was evaluated in relation to allergy versus tolerance to peanut and validated in an independent population (n = 65). BAT in peanut-allergic children showed a peanut dose-dependent upregulation of CD63 and CD203c while there was no significant response to peanut in peanut-sensitized but tolerant (P < .001) and non-peanut-sensitized nonallergic children (P < .001). BAT optimal diagnostic cutoffs showed 97% accuracy, 95% positive predictive value, and 98% negative predictive value. BAT allowed reducing the number of required OFCs by two-thirds. BAT proved particularly useful in cases in which specialists could not accurately diagnose peanut allergy with SPT and sIgE to peanut and to Arah2. Using a 2-step diagnostic approach in which BAT was performed only after equivocal SPT or Arah2-sIgE, BAT had a major effect (97% reduction) on the number of OFCs required. BAT proved to be superior to other diagnostic tests in discriminating between peanut allergy and tolerance, particularly in difficult cases, and reduced the need for OFCs. Copyright © 2014. Published by Elsevier Inc.

The role of routine preoperative EUS when performed after contrast enhanced CT in the diagnostic work-up in patients suspected of pancreatic or periampullary cancer.

PubMed

Cieslak, Kasia P; van Santvoort, Hjalmar C; Vleggaar, Frank P; van Leeuwen, Maarten S; ten Kate, Fibo J; Besselink, Marc G; Molenaar, I Quintus

2014-01-01

In patients suspected of pancreatic or periampullary cancer, abdominal contrast-enhanced computed tomography (CT) is the standard diagnostic modality. A supplementary endoscopic ultrasonography (EUS) is often performed, although there is only limited evidence of its additional diagnostic value. The aim of the study is to evaluate the additional diagnostic value of EUS over CT in deciding on exploratory laparotomy in patients suspected of pancreatic or periampullary cancer. We retrospectively analyzed 86 consecutive patients who routinely underwent CT and EUS before exploratory laparotomy with or without pancreatoduodenectomy for suspected pancreatic or periampullary carcinoma between 2007 and 2010. Primary outcomes were visibility of a mass, resectability on CT/EUS and resection with curative intent. A mass was visible on CT in 72/86 (84%) patients. In these 72 patients, EUS demonstrated a mass in 64/72 (89%) patients. Resectability was accurately predicted by CT in 65/72 (90%) and by EUS in 58/72 (81%) patients. In 14/86 (16%) patients no mass was seen on CT. EUS showed a mass in 12/14 (86%) of these patients. A malignant lesion was histological proven in 11/12 (92%) of these patients. Overall, resectability was accurately predicted by CT and EUS in 90% (77/86) and 84% (72/86), respectively. In patients with a visible mass on CT, suspected for pancreatic or periampullary cancer, EUS has no additional diagnostic value, does not influence the decision to perform laparotomy and should therefore not be performed routinely. In patients without a visible mass on CT, EUS is useful to confirm the presence of a tumor. Copyright © 2014 IAP and EPC. Published by Elsevier B.V. All rights reserved.

Influence diagnostics for count data under AB-BA crossover trials.

PubMed

Hao, Chengcheng; von Rosen, Dietrich; von Rosen, Tatjana

2017-12-01

This paper aims to develop diagnostic measures to assess the influence of data perturbations on estimates in AB-BA crossover studies with a Poisson distributed response. Generalised mixed linear models with normally distributed random effects are utilised. We show that in this special case, the model can be decomposed into two independent sub-models which allow to derive closed-form expressions to evaluate the changes in the maximum likelihood estimates under several perturbation schemes. The performance of the new influence measures is illustrated by simulation studies and the analysis of a real dataset.

Evaluation of cloud detection instruments and performance of laminar-flow leading-edge test articles during NASA Leading-Edge Flight-Test Program

NASA Technical Reports Server (NTRS)

Davis, Richard E.; Maddalon, Dal V.; Wagner, Richard D.; Fisher, David F.; Young, Ronald

1989-01-01

Summary evaluations of the performance of laminar-flow control (LFC) leading edge test articles on a NASA JetStar aircraft are presented. Statistics, presented for the test articles' performance in haze and cloud situations, as well as in clear air, show a significant effect of cloud particle concentrations on the extent of laminar flow. The cloud particle environment was monitored by two instruments, a cloud particle spectrometer (Knollenberg probe) and a charging patch. Both instruments are evaluated as diagnostic aids for avoiding laminar-flow detrimental particle concentrations in future LFC aircraft operations. The data base covers 19 flights in the simulated airline service phase of the NASA Leading-Edge Flight-Test (LEFT) Program.

Battery testing at Argonne National Laboratory

NASA Astrophysics Data System (ADS)

Deluca, W. H.; Gillie, K. R.; Kulaga, J. E.; Smaga, J. A.; Tummillo, A. F.; Webster, C. E.

1993-03-01

Argonne National Laboratory's Analysis & Diagnostic Laboratory (ADL) tests advanced batteries under simulated electric and hybrid vehicle operating conditions. The ADL facilities also include a post-test analysis laboratory to determine, in a protected atmosphere if needed, component compositional changes and failure mechanisms. The ADL provides a common basis for battery performance characterization and life evaluations with unbiased application of tests and analyses. The battery evaluations and post-test examinations help identify factors that limit system performance and life and the most-promising R&D approaches for overcoming these limitations. Since 1991, performance characterizations and/or life evaluations have been conducted on eight battery technologies: Na/S, Li/S, Zn/Br, Ni/MH, Ni/Zn, Ni/Cd, Ni/Fe, and lead-acid. These evaluations were performed for the Department of Energy's. Office of Transportation Technologies, Electric and Hybrid Propulsion Division (DOE/OTT/EHP), and Electric Power Research Institute (EPRI) Transportation Program. The results obtained are discussed.

Sensor fusion display evaluation using information integration models in enhanced/synthetic vision applications

NASA Technical Reports Server (NTRS)

Foyle, David C.

1993-01-01

Based on existing integration models in the psychological literature, an evaluation framework is developed to assess sensor fusion displays as might be implemented in an enhanced/synthetic vision system. The proposed evaluation framework for evaluating the operator's ability to use such systems is a normative approach: The pilot's performance with the sensor fusion image is compared to models' predictions based on the pilot's performance when viewing the original component sensor images prior to fusion. This allows for the determination as to when a sensor fusion system leads to: poorer performance than one of the original sensor displays, clearly an undesirable system in which the fused sensor system causes some distortion or interference; better performance than with either single sensor system alone, but at a sub-optimal level compared to model predictions; optimal performance compared to model predictions; or, super-optimal performance, which may occur if the operator were able to use some highly diagnostic 'emergent features' in the sensor fusion display, which were unavailable in the original sensor displays.

Evaluation and management of gunshot wounds of the penis: 20-year experience at an urban trauma center.

PubMed

Kunkle, David A; Lebed, Brett D; Mydlo, Jack H; Pontari, Michel A

2008-04-01

Although gunshot injuries to the penis occur relatively infrequently in patients with penetrating trauma, they often present dilemmas of subsequent evaluation and management. We review our extensive experience with gunshot wounds to the penis at a high volume urban trauma center. The urologic trauma database was retrospectively reviewed to extract and compile information from the records of 63 patients treated for gunshot wounds to the penis. Data were accumulated for a 20-year period from 1985 to 2004 with regard to findings on physical examination, diagnostic evaluation, associated injuries, management, and outcome. We detail our technique of penile exploration and artificial erection in the management of these injuries. Penile gunshot wounds were associated with additional injuries in 53 of 63 (84%) patients. A total of 48 (76%) patients were taken to the operating room and 44 (70%) penile explorations were performed. Evaluation included retrograde urethrogram in 50 of 63 (79%) patients and was diagnostic for urethral injury in 11 of 12 (92%) cases. Primary urethral repair was performed in 8 of 12 (67%) patients with urethral injury versus 4 of 12 (33%) who underwent urinary diversion by means of suprapubic cystotomy. Evaluation and management of gunshot wounds to the penis may potentially be complex. Retrograde urethrogram should be performed in all cases except the most insignificant and superficial wounds. We describe our technique of penile exploration and artificial erection, noting excellent results in patients for whom follow-up is available. Additional studies are needed to prospectively evaluate techniques for management of gunshot urethral injuries.

Comparative Capabilities of Clinical Assessment, Diagnostic Criteria, and Polysomnography in Detecting Sleep Bruxism

PubMed Central

Palinkas, Marcelo; De Luca Canto, Graziela; Rodrigues, Laíse Angélica Mendes; Bataglion, César; Siéssere, Selma; Semprini, Marisa; Regalo, Simone Cecilio Hallak

2015-01-01

Objective: To evaluate the diagnostic capability of signs and symptoms of sleep bruxism (SB) as per the American Academy of Sleep Medicine (AASM) criteria and a diagnostic grading system proposed by international experts for assessing SB. Methods: The study was conducted in three phases (interview, physical examination, and sleep studies). Subjects were asked about self-reported tooth grinding sounds occurring during sleep, muscle fatigue, temporal headaches, jaw muscle pain, and jaw locking. A visual examination was conducted to check for presence of abnormal tooth wear. A full-night polysomnography (PSG) was performed. After three phases, the subjects were divided into two groups matched by age and gender: Case Group, 45 SB subjects, and Control Group, 45 non-SB subjects. Diagnostic accuracy measurements were calculated for each sign or symptom individually and for the two diagnostic criteria analyzed. Results: Muscle fatigue, temporal headaches, and AASM criteria were associated with highest sensitivity (78%, 67%, 58%, respectively) and also with highest diagnostic odds ratio (OR = 9.63, 9.25, 6.33, respectively). Jaw locking, muscle pain, and the criterion of “probable SB” were associated with the worst sensitivity (16%, 18%, 22%, respectively). Conclusions: Presence of muscle fatigue and temporal headaches can be considered good tools to screen SB patients. None of the diagnostic criteria evaluated was able to accurately identify patients with SB. AASM criteria had the strongest diagnostic capabilities and—although they do not attain diagnostic values high enough to replace the current gold standard (PSG)—should be used as a screening tool to identify SB. Citation: Palinkas M, De Luca Canto G, Rodrigues LA, Bataglion C, Siéssere S, Semprini M, Regalo SC. Comparative capabilities of clinical assessment, diagnostic criteria, and polysomnography in detecting sleep bruxism. J Clin Sleep Med 2015;11(11):1319–1325. PMID:26235152

Conversion-Integration of MSFC Nonlinear Signal Diagnostic Analysis Algorithms for Realtime Execution of MSFC's MPP Prototype System

NASA Technical Reports Server (NTRS)

Jong, Jen-Yi

1996-01-01

NASA's advanced propulsion system Small Scale Magnetic Disturbances/Advanced Technology Development (SSME/ATD) has been undergoing extensive flight certification and developmental testing, which involves large numbers of health monitoring measurements. To enhance engine safety and reliability, detailed analysis and evaluation of the measurement signals are mandatory to assess its dynamic characteristics and operational condition. Efficient and reliable signal detection techniques will reduce the risk of catastrophic system failures and expedite the evaluation of both flight and ground test data, and thereby reduce launch turn-around time. During the development of SSME, ASRI participated in the research and development of several advanced non- linear signal diagnostic methods for health monitoring and failure prediction in turbomachinery components. However, due to the intensive computational requirement associated with such advanced analysis tasks, current SSME dynamic data analysis and diagnostic evaluation is performed off-line following flight or ground test with a typical diagnostic turnaround time of one to two days. The objective of MSFC's MPP Prototype System is to eliminate such 'diagnostic lag time' by achieving signal processing and analysis in real-time. Such an on-line diagnostic system can provide sufficient lead time to initiate corrective action and also to enable efficient scheduling of inspection, maintenance and repair activities. The major objective of this project was to convert and implement a number of advanced nonlinear diagnostic DSP algorithms in a format consistent with that required for integration into the Vanderbilt Multigraph Architecture (MGA) Model Based Programming environment. This effort will allow the real-time execution of these algorithms using the MSFC MPP Prototype System. ASRI has completed the software conversion and integration of a sequence of nonlinear signal analysis techniques specified in the SOW for real-time execution on MSFC's MPP Prototype. This report documents and summarizes the results of the contract tasks; provides the complete computer source code; including all FORTRAN/C Utilities; and all other utilities/supporting software libraries that are required for operation.

A manifesto for cardiovascular imaging: addressing the human factor†

PubMed Central

Fraser, Alan G

2017-01-01

Abstract Our use of modern cardiovascular imaging tools has not kept pace with their technological development. Diagnostic errors are common but seldom investigated systematically. Rather than more impressive pictures, our main goal should be more precise tests of function which we select because their appropriate use has therapeutic implications which in turn have a beneficial impact on morbidity or mortality. We should practise analytical thinking, use checklists to avoid diagnostic pitfalls, and apply strategies that will reduce biases and avoid overdiagnosis. We should develop normative databases, so that we can apply diagnostic algorithms that take account of variations with age and risk factors and that allow us to calculate pre-test probability and report the post-test probability of disease. We should report the imprecision of a test, or its confidence limits, so that reference change values can be considered in daily clinical practice. We should develop decision support tools to improve the quality and interpretation of diagnostic imaging, so that we choose the single best test irrespective of modality. New imaging tools should be evaluated rigorously, so that their diagnostic performance is established before they are widely disseminated; this should be a shared responsibility of manufacturers with clinicians, leading to cost-effective implementation. Trials should evaluate diagnostic strategies against independent reference criteria. We should exploit advances in machine learning to analyse digital data sets and identify those features that best predict prognosis or responses to treatment. Addressing these human factors will reap benefit for patients, while technological advances continue unpredictably. PMID:29029029

Image processing and machine learning for fully automated probabilistic evaluation of medical images.

PubMed

Sajn, Luka; Kukar, Matjaž

2011-12-01

The paper presents results of our long-term study on using image processing and data mining methods in a medical imaging. Since evaluation of modern medical images is becoming increasingly complex, advanced analytical and decision support tools are involved in integration of partial diagnostic results. Such partial results, frequently obtained from tests with substantial imperfections, are integrated into ultimate diagnostic conclusion about the probability of disease for a given patient. We study various topics such as improving the predictive power of clinical tests by utilizing pre-test and post-test probabilities, texture representation, multi-resolution feature extraction, feature construction and data mining algorithms that significantly outperform medical practice. Our long-term study reveals three significant milestones. The first improvement was achieved by significantly increasing post-test diagnostic probabilities with respect to expert physicians. The second, even more significant improvement utilizes multi-resolution image parametrization. Machine learning methods in conjunction with the feature subset selection on these parameters significantly improve diagnostic performance. However, further feature construction with the principle component analysis on these features elevates results to an even higher accuracy level that represents the third milestone. With the proposed approach clinical results are significantly improved throughout the study. The most significant result of our study is improvement in the diagnostic power of the whole diagnostic process. Our compound approach aids, but does not replace, the physician's judgment and may assist in decisions on cost effectiveness of tests. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Improving early cycle economic evaluation of diagnostic technologies.

PubMed

Steuten, Lotte M G; Ramsey, Scott D

2014-08-01

The rapidly increasing range and expense of new diagnostics, compels consideration of a different, more proactive approach to health economic evaluation of diagnostic technologies. Early cycle economic evaluation is a decision analytic approach to evaluate technologies in development so as to increase the return on investment as well as patient and societal impact. This paper describes examples of 'early cycle economic evaluations' as applied to diagnostic technologies and highlights challenges in its real-time application. It shows that especially in the field of diagnostics, with rapid technological developments and a changing regulatory climate, early cycle economic evaluation can have a guiding role to improve the efficiency of the diagnostics innovation process. In the next five years the attention will move beyond the methodological and analytic challenges of early cycle economic evaluation towards the challenge of effectively applying it to improve diagnostic research and development and patient value. Future work in this area should therefore be 'strong on principles and soft on metrics', that is, the metrics that resonate most clearly with the various decision makers in this field.

A systematic review and meta-analysis of diagnostic test of MRA versus MRI for detection superior labrum anterior to posterior lesions type II-VII.

PubMed

Arirachakaran, Alisara; Boonard, Manusak; Chaijenkij, Kornkit; Pituckanotai, Kwanchai; Prommahachai, Akom; Kongtharvonskul, Jatupon

2017-02-01

To determine the diagnostic performance of magnetic resonance arthrography (MRA) and magnetic resonance imaging (MRI) in superior labrum anterior to posterior lesions (type II-VII) of the shoulder. PubMed and Scopus search engines, an electronic search of articles was performed from inception to February 19, 2016. Diagnostic performance of index tests was compared by the summary area under receiver operator characteristic curve (AUROC). In all, 117 of 493 studies were eligible and 32 studies (2,013 shoulders) and 11 studies (1,498 shoulders) were evaluated with MRA and MRI. The summary sensitivity, specificity, likelihood ratio (positive and negative) and AUROC were 0.87 (95 % confidence interval, CI: 0.82, 0.91), 0.92 (95 %CI: 0.85, 0.95), 10.28 (95 %CI: 5.84, 18.08), 0.14 (95 %CI: 0.10, 0.20) and 0.94 (95 %CI: 0.92, 0.96) respectively for MRA, and 0.76 (95 %CI: 0.61, 0.86), 0.87 (95 %CI: 0.71, 0.95), 5.89 (95 %CI: 2.5, 13.86), 0.28 (95 %CI: 0.17, 0.47) and 0.94 (95 %CI: 0.92, 0.96) respectively for MRI. The diagnostic performance of MRA was superior to MRI by both direct and indirect comparisons for the detection of SLAP lesions.

Transbronchial Lung Cryobiopsy and Video-assisted Thoracoscopic Lung Biopsy in the Diagnosis of Diffuse Parenchymal Lung Disease. A Meta-analysis of Diagnostic Test Accuracy.

PubMed

Iftikhar, Imran H; Alghothani, Lana; Sardi, Alejandro; Berkowitz, David; Musani, Ali I

2017-07-01

Transbronchial lung cryobiopsy is increasingly being used for the assessment of diffuse parenchymal lung diseases. Several studies have shown larger biopsy samples and higher yields compared with conventional transbronchial biopsies. However, the higher risk of bleeding and other complications has raised concerns for widespread use of this modality. To study the diagnostic accuracy and safety profile of transbronchial lung cryobiopsy and compare with video-assisted thoracoscopic surgery (VATS) by reviewing available evidence from the literature. Medline and PubMed were searched from inception until December 2016. Data on diagnostic performance were abstracted by constructing two-by-two contingency tables for each study. Data on a priori selected safety outcomes were collected. Risk of bias was assessed with the Quality Assessment of Diagnostic Accuracy Studies tool. Random effects meta-analyses were performed to obtain summary estimates of the diagnostic accuracy. The pooled diagnostic yield, pooled sensitivity, and pooled specificity of transbronchial lung cryobiopsy were 83.7% (76.9-88.8%), 87% (85-89%), and 57% (40-73%), respectively. The pooled diagnostic yield, pooled sensitivity, and pooled specificity of VATS were 92.7% (87.6-95.8%), 91.0% (89-92%), and 58% (31-81%), respectively. The incidence of grade 2 (moderate to severe) endobronchial bleeding after transbronchial lung cryobiopsy and of post-procedural pneumothorax was 4.9% (2.2-10.7%) and 9.5% (5.9-14.9%), respectively. Although the diagnostic test accuracy measures of transbronchial lung cryobiopsy lag behind those of VATS, with an acceptable safety profile and potential cost savings, the former could be considered as an alternative in the evaluation of patients with diffuse parenchymal lung diseases.

Feasibility of dynamic cardiac ultrasound transmission via mobile phone for basic emergency teleconsultation.

PubMed

Lim, Tae Ho; Choi, Hyuk Joong; Kang, Bo Seung

2010-01-01

We assessed the feasibility of using a camcorder mobile phone for teleconsulting about cardiac echocardiography. The diagnostic performance of evaluating left ventricle (LV) systolic function was measured by three emergency medicine physicians. A total of 138 short echocardiography video sequences (from 70 subjects) was selected from previous emergency room ultrasound examinations. The measurement of LV ejection fraction based on the transmitted video displayed on a mobile phone was compared with the original video displayed on the LCD monitor of the ultrasound machine. The image quality was evaluated using the double stimulation impairment scale (DSIS). All observers showed high sensitivity. There was an improvement in specificity with the observer's increasing experience of cardiac ultrasound. Although the image quality of video on the mobile phone was lower than that of the original, a receiver operating characteristic (ROC) analysis indicated that there was no significant difference in diagnostic performance. Immediate basic teleconsulting of echocardiography movies is possible using current commercially-available mobile phone systems.