Evaluating a mobile application for improving clinical laboratory test ordering and diagnosis.

PubMed

Meyer, Ashley N D; Thompson, Pamela J; Khanna, Arushi; Desai, Samir; Mathews, Benji K; Yousef, Elham; Kusnoor, Anita V; Singh, Hardeep

2018-04-20

Mobile applications for improving diagnostic decision making often lack clinical evaluation. We evaluated if a mobile application improves generalist physicians' appropriate laboratory test ordering and diagnosis decisions and assessed if physicians perceive it as useful for learning. In an experimental, vignette study, physicians diagnosed 8 patient vignettes with normal prothrombin times (PT) and abnormal partial thromboplastin times (PTT). Physicians made test ordering and diagnosis decisions for 4 vignettes using each resource: a mobile app, PTT Advisor, developed by the Centers for Disease Control and Prevention (CDC)'s Clinical Laboratory Integration into Healthcare Collaborative (CLIHC); and usual clinical decision support. Then, physicians answered questions regarding their perceptions of the app's usefulness for diagnostic decision making and learning using a modified Kirkpatrick Training Evaluation Framework. Data from 368 vignettes solved by 46 physicians at 7 US health care institutions show advantages for using PTT Advisor over usual clinical decision support on test ordering and diagnostic decision accuracy (82.6 vs 70.2% correct; P < .001), confidence in decisions (7.5 vs 6.3 out of 10; P < .001), and vignette completion time (3:02 vs 3:53 min.; P = .06). Physicians reported positive perceptions of the app's potential for improved clinical decision making, and recommended it be used to address broader diagnostic challenges. A mobile app, PTT Advisor, may contribute to better test ordering and diagnosis, serve as a learning tool for diagnostic evaluation of certain clinical disorders, and improve patient outcomes. Similar methods could be useful for evaluating apps aimed at improving testing and diagnosis for other conditions.

Diagnosing pulmonary embolisms: the clinician's point of view.

PubMed

Carrillo Alcaraz, A; Martínez, A López; Solano, F J Sotos

Pulmonary thromboembolism is common and potentially severe. To ensure the correct approach to the diagnostic workup of pulmonary thromboembolism, it is essential to know the basic concepts governing the use of the different tests available. The diagnostic approach to pulmonary thromboembolism is an example of the application of the conditional probabilities of Bayes' theorem in daily practice. To interpret the available diagnostic tests correctly, it is necessary to analyze different concepts that are fundamental for decision making. Thus, it is necessary to know what the likelihood ratios, 95% confidence intervals, and decision thresholds mean. Whether to determine the D-dimer concentration or to do CT angiography or other imaging tests depends on their capacity to modify the pretest probability of having the disease to a posttest probability that is higher or lower than the thresholds for action. This review aims to clarify the diagnostic sequence of thromboembolic pulmonary disease, analyzing the main diagnostic tools (clinical examination, laboratory tests, and imaging tests), placing special emphasis on the principles that govern evidence-based medicine. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

An electronic thesaurus of Evidence Based Laboratory Medicine hematological and biochemical diagnostic tests.

PubMed

Dorizzi, R M; Maconi, M; Giavarina, D; Loza, G; Aman, M; Moreira, J; Bisoffi, Z; Gennuso, C

2009-10-01

The adoption of Evidence Based Laboratory Medicine (EBLM) has been hampered until today by the lack of effective tools. The SIMeL EBLM e-Thesaurus (on-line Repertoire of the diagnostic effectiveness of the laboratory, radiology and cardiology test) provides a useful support to clinical laboratory professionals and to clinicians for the interpretation of the diagnostic tests. The e-Thesaurus is an application developed using Microsoft Active Server Pages technology and carried out with Web Server Microsoft Internet Information Server and is available at the SIMeL website using a browser running JavaScript scripts (Internet Explorer is recommended). It contains a database (in Italian, English and Spanish) of the sensitivity and specificity (including the 95% confidence interval), the positive and negative likelihood ratios, the Diagnostic Odds Ratio and the Number Needed to Diagnose of more than 2000 diagnostic (most laboratory but also cardiology and radiology) tests. The e-Thesaurus improves the previous SIMeL paper and CD Thesaurus; its main features are a three languages search and a continuous and an easy updating capability.

The impact of communication barriers on diagnostic confidence and ancillary testing in the emergency department.

PubMed

Garra, Gregory; Albino, Hiram; Chapman, Heather; Singer, Adam J; Thode, Henry C

2010-06-01

Communication barriers (CBs) compromise the diagnostic power of the medical interview and may result in increased reliance on diagnostic tests or incorrect test ordering. The prevalence and degree to which these barriers affect diagnosis, testing, and treatment are unknown. To quantify and characterize CBs encountered in the Emergency Department (ED), and assess the effect of CBs on initial diagnosis and perceived reliance on ancillary testing. This was a prospective survey completed by emergency physicians after initial adult patient encounters. CB severity, diagnostic confidence, and reliance on ancillary testing were quantified on a 100-mm Visual Analog Scale (VAS) from least (0) to most (100). Data were collected on 417 ED patient encounters. CBs were reported in 46%; with a mean severity of 50 mm on a 100-mm VAS with endpoints of "perfect communication and "no communication." Language was the most commonly reported form of CB (28%). More than one CB was identified in 6%. The 100-mm VAS rating of diagnostic confidence was lower in patients with perceived CBs (64 mm) vs. those without CBs (80 mm), p < 0.001. VAS ratings of physician reliance on ancillary testing was higher in patients with perceived CBs (50 mm) vs. patients without a perceived CB (38 mm), p < 0.001. Communication barriers in our ED setting were common, and resulted in lower diagnostic confidence and increased perception that ancillary tests are needed to narrow the diagnosis. Copyright 2010 Elsevier Inc. 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.

A Systematic Review and Aggregated Analysis on the Impact of Amyloid PET Brain Imaging on the Diagnosis, Diagnostic Confidence, and Management of Patients being Evaluated for Alzheimer's Disease.

PubMed

Fantoni, Enrico R; Chalkidou, Anastasia; O' Brien, John T; Farrar, Gill; Hammers, Alexander

2018-01-01

Amyloid PET (aPET) imaging could improve patient outcomes in clinical practice, but the extent of impact needs quantification. To provide an aggregated quantitative analysis of the value added by aPET in cognitively impaired subjects. Systematic literature searches were performed in Embase and Medline until January 2017. 1,531 cases over 12 studies were included (1,142 cases over seven studies in the primary analysis where aPET was the key biomarker; the remaining cases included as defined groups in the secondary analysis). Data was abstracted by consensus among two observers and assessed for bias. Clinical utility was measured by diagnostic change, diagnostic confidence, and patient management before and after aPET. Three groups were further analyzed: control patients for whom feedback of aPET scan results was delayed; aPET Appropriate Use Criteria (AUC+) cases; and patients undergoing additional FDG/CSF testing. For 1,142 cases with only aPET, 31.3% of diagnoses were revised, whereas 3.2% of diagnoses changed in the delayed aPET control group (p < 0.0001). Increased diagnostic confidence following aPET was found for 62.1% of 870 patients. Management changes with aPET were found in 72.2% of 740 cases and in 55.5% of 299 cases in the control group (p < 0.0001). The diagnostic value of aPET in AUC+ patients or when FDG/CSF were additionally available did not substantially differ from the value of aPET alone in the wider population. Amyloid PET contributed to diagnostic revision in almost a third of cases and demonstrated value in increasing diagnostic confidence and refining management plans.

A Systematic Review and Aggregated Analysis on the Impact of Amyloid PET Brain Imaging on the Diagnosis, Diagnostic Confidence, and Management of Patients being Evaluated for Alzheimer’s Disease

PubMed Central

Fantoni, Enrico R.; Chalkidou, Anastasia; O’ Brien, John T.; Farrar, Gill; Hammers, Alexander

2018-01-01

Background: Amyloid PET (aPET) imaging could improve patient outcomes in clinical practice, but the extent of impact needs quantification. Objective: To provide an aggregated quantitative analysis of the value added by aPET in cognitively impaired subjects. Methods: Systematic literature searches were performed in Embase and Medline until January 2017. 1,531 cases over 12 studies were included (1,142 cases over seven studies in the primary analysis where aPET was the key biomarker; the remaining cases included as defined groups in the secondary analysis). Data was abstracted by consensus among two observers and assessed for bias. Clinical utility was measured by diagnostic change, diagnostic confidence, and patient management before and after aPET. Three groups were further analyzed: control patients for whom feedback of aPET scan results was delayed; aPET Appropriate Use Criteria (AUC+) cases; and patients undergoing additional FDG/CSF testing. Results: For 1,142 cases with only aPET, 31.3% of diagnoses were revised, whereas 3.2% of diagnoses changed in the delayed aPET control group (p < 0.0001). Increased diagnostic confidence following aPET was found for 62.1% of 870 patients. Management changes with aPET were found in 72.2% of 740 cases and in 55.5% of 299 cases in the control group (p < 0.0001). The diagnostic value of aPET in AUC+ patients or when FDG/CSF were additionally available did not substantially differ from the value of aPET alone in the wider population. Conclusions: Amyloid PET contributed to diagnostic revision in almost a third of cases and demonstrated value in increasing diagnostic confidence and refining management plans. PMID:29689725

Quantitative Myocardial Perfusion Imaging Versus Visual Analysis in Diagnosing Myocardial Ischemia: A CE-MARC Substudy.

PubMed

Biglands, John D; Ibraheem, Montasir; Magee, Derek R; Radjenovic, Aleksandra; Plein, Sven; Greenwood, John P

2018-05-01

This study sought to compare the diagnostic accuracy of visual and quantitative analyses of myocardial perfusion cardiovascular magnetic resonance against a reference standard of quantitative coronary angiography. Visual analysis of perfusion cardiovascular magnetic resonance studies for assessing myocardial perfusion has been shown to have high diagnostic accuracy for coronary artery disease. However, only a few small studies have assessed the diagnostic accuracy of quantitative myocardial perfusion. This retrospective study included 128 patients randomly selected from the CE-MARC (Clinical Evaluation of Magnetic Resonance Imaging in Coronary Heart Disease) study population such that the distribution of risk factors and disease status was proportionate to the full population. Visual analysis results of cardiovascular magnetic resonance perfusion images, by consensus of 2 expert readers, were taken from the original study reports. Quantitative myocardial blood flow estimates were obtained using Fermi-constrained deconvolution. The reference standard for myocardial ischemia was a quantitative coronary x-ray angiogram stenosis severity of ≥70% diameter in any coronary artery of >2 mm diameter, or ≥50% in the left main stem. Diagnostic performance was calculated using receiver-operating characteristic curve analysis. The area under the curve for visual analysis was 0.88 (95% confidence interval: 0.81 to 0.95) with a sensitivity of 81.0% (95% confidence interval: 69.1% to 92.8%) and specificity of 86.0% (95% confidence interval: 78.7% to 93.4%). For quantitative stress myocardial blood flow the area under the curve was 0.89 (95% confidence interval: 0.83 to 0.96) with a sensitivity of 87.5% (95% confidence interval: 77.3% to 97.7%) and specificity of 84.5% (95% confidence interval: 76.8% to 92.3%). There was no statistically significant difference between the diagnostic performance of quantitative and visual analyses (p = 0.72). Incorporating rest myocardial blood flow values to generate a myocardial perfusion reserve did not significantly increase the quantitative analysis area under the curve (p = 0.79). Quantitative perfusion has a high diagnostic accuracy for detecting coronary artery disease but is not superior to visual analysis. The incorporation of rest perfusion imaging does not improve diagnostic accuracy in quantitative perfusion analysis. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Integration of CT urography improves diagnostic confidence of 68Ga-PSMA-11 PET/CT in prostate cancer patients.

PubMed

Will, Leon; Giesel, Frederik L; Freitag, Martin T; Berger, Anne K; Mier, Walter; Kopka, Klaus; Koerber, Stefan A; Rathke, Hendrik; Kremer, Christophe; Kratochwil, Clemens; Kauczor, Hans-Ulrich; Haberkorn, Uwe; Weber, Tim F

2017-12-20

To prove the feasibility of integrating CT urography (CTU) into 68 Ga-PSMA-11 PET/CT and to analyze the impact of CTU on assigning focal tracer accumulation in the ureteric space to either ureteric excretion or metastatic disease concerning topographic attribution and diagnostic confidence. Ten prostate cancer patients who underwent 68 Ga-PSMA-11 PET/CT including CTU because of biochemical relapse or known metastatic disease were retrospectively analyzed. CTU consisted of an excretory phase 10 min after injection of 80 mL iodinated contrast material. Ureter opacification at CTU was evaluated using the following score: 0, 0% opacification; 1, < 50%; 2, 50-99%; 3, 100%. Topographic attribution and confidence of topographic attribution of focal tracer accumulation in the ureteric space were separately assessed for 68 Ga-PSMA-11 PET/CT without and with CTU. Diagnostic confidence was evaluated using the following score: 0, < 25% confidence; 1, 26-50%; 2, 51-75%; 3, 76-100%. At CTU, mean ureter opacification score was 2.6 ± 0.7. At 68 Ga-PSMA-11 PET/CT without CTU, mean confidence of topographic attribution of focal tracer accumulation was 2.5 ± 0.7 in total and 2.6 ± 0.7 for metastatic disease. At 68 Ga-PSMA-11 PET/CT with CTU, mean confidence of topographic attribution of focal areas of tracer accumulation was significantly higher with 2.9 ± 0.2 in total and 2.7 ± 0.9 for metastatic disease (p < 0.001). In 4 of 34 findings (12%) attribution to either ureteric excretion or metastatic disease was discrepant between 68 Ga-PSMA-11 PET/CT without and with CTU (n.s). Integration of CTU into 68 Ga-PSMA-11 PET/CT is feasible and increases diagnostic confidence of assigning focal areas of tracer accumulation in the ureteric space to either metastatic disease or ureteric excretion.

Independent value of image fusion in unenhanced breast MRI using diffusion-weighted and morphological T2-weighted images for lesion characterization in patients with recently detected BI-RADS 4/5 x-ray mammography findings.

PubMed

Bickelhaupt, Sebastian; Tesdorff, Jana; Laun, Frederik Bernd; Kuder, Tristan Anselm; Lederer, Wolfgang; Teiner, Susanne; Maier-Hein, Klaus; Daniel, Heidi; Stieber, Anne; Delorme, Stefan; Schlemmer, Heinz-Peter

2017-02-01

The aim of this study was to evaluate the accuracy and applicability of solitarily reading fused image series of T2-weighted and high-b-value diffusion-weighted sequences for lesion characterization as compared to sequential or combined image analysis of these unenhanced sequences and to contrast- enhanced breast MRI. This IRB-approved study included 50 female participants with suspicious breast lesions detected in screening X-ray mammograms, all of which provided written informed consent. Prior to biopsy, all women underwent MRI including diffusion-weighted imaging (DWIBS, b = 1500s/mm 2 ). Images were analyzed as follows: prospective image fusion of DWIBS and T2-weighted images (FU), side-by-side analysis of DWIBS and T2-weighted series (CO), combination of the first two methods (CO+FU), and full contrast-enhanced diagnostic protocol (FDP). Diagnostic indices, confidence, and image quality of the protocols were compared by two blinded readers. Reading the CO+FU (accuracy 0.92; NPV 96.1 %; PPV 87.6 %) and the CO series (0.90; 96.1 %; 83.7 %) provided a diagnostic performance similar to the FDP (0.95; 96.1 %; 91.3 %; p > 0.05). FU reading alone significantly reduced the diagnostic accuracy (0.82; 93.3 %; 73.4 %; p = 0.023). MR evaluation of suspicious BI-RADS 4 and 5 lesions detected on mammography by using a non-contrast-enhanced T2-weighted and DWIBS sequence protocol is most accurate if MR images were read using the CO+FU protocol. • Unenhanced breast MRI with additional DWIBS/T2w-image fusion allows reliable lesion characterization. • Abbreviated reading of fused DWIBS/T2w-images alone decreases diagnostic confidence and accuracy. • Reading fused DWIBS/T2w-images as the sole diagnostic method should be avoided.

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.

An Investigation of Diagnostic Accuracy and Confidence Associated with Diagnostic Checklists as Well as Gender Biases in Relation to Mental Disorders.

PubMed

Cwik, Jan C; Papen, Fabienne; Lemke, Jan-Erik; Margraf, Jürgen

2016-01-01

This study examines the utility of checklists in attaining more accurate diagnoses in the context of diagnostic decision-making for mental disorders. The study also aimed to replicate results from a meta-analysis indicating that there is no association between patients' gender and misdiagnoses. To this end, 475 psychotherapists were asked to judge three case vignettes describing patients with Major Depressive Disorder (MDD), Generalized Anxiety Disorder, and Borderline Personality Disorder. Therapists were randomly assigned to experimental conditions in a 2 (diagnostic method: with using diagnostic checklists vs. without using diagnostic checklists) × 2 (gender: male vs. female case vignettes) between-subjects design. Multinomial logistic and linear regression analyses were used to examine the association between the usage of diagnostic checklists as well as patients' gender and diagnostic decisions. The results showed that when checklists were used, fewer incorrect co-morbid diagnoses were made, but clinicians were less likely to diagnose MDD even when the criteria were met. Additionally, checklists improved therapists' confidence with diagnostic decisions, but were not associated with estimations of patients' characteristics. As expected, there were no significant associations between gender and diagnostic decisions.

Computed tomographic (CT) neuroradiological evaluation of intra-axial and extra-axial lesions: a receiver operating characteristic (ROC) study of film and 1K workstation

NASA Astrophysics Data System (ADS)

El-Saden, Suzie; Hademenos, George J.; Zhu, Wei; Sayre, James W.; Glenn, Brad; Steidler, Jim; Kode, L.; King, Brian; Quinones, Diana; Valentino, Daniel J.; Bentsen, John R.

1995-04-01

Digital display workstations are now commonly used for cross-sectional image viewing; however, few receiver operating characteristic (ROC) studies have been performed to evaluate the diagnostic efficiency of hard copy versus a workstation display for neuroradiology applications. We have performed an ROC study of film and 1K workstation based on the diagnostic performance of neuroradiology fellows to detect subtle intra- axial (high density (HD) and low density (LD)) and extra-axial (fluid, blood) lesions presented on computed tomographic (CT) images. An ROC analysis of the interpretation of approximately 200 CT images (1/2 normals and 1/2 abnormals) was performed by five experienced observers. The total number of abnormal images were equally divided among the three represented types of lesions (HD, LD, and extra-axial lesions). The images comprising the extra-axial lesion group were further subdivided into the following three distinct types: subdural hemorrhage, subarachnoid hemorrhage, and epidural hemorrhage. A fraction of the abnormal images were represented by more than one type of lesion, e.g., one abnormal image could contain both a HD and LD lesion. The digitized CT images were separated into four groups and read on the standard light box and a 1K workstation monitor equipped with simple image processing functions. Confidence ratings were scaled on a range from 0 (least confident) to 4 (most confident). Reader order sequences were randomized for each reader and for each modality. Each observer read from a total of eight different groups with a four-week intermission following the fourth group. The randomly assigned image number, lesion type and approximate location, incidental findings and comments, and confidence ratings were reported in individual worksheets for each image. ROC curves that were generated and analyzed for the various subgroups are presented in addition to the overall generalized jackknifed estimates of the grouped data. Also, 95% confidence intervals are presented for the differences in the area under the ROC curves. Although there were no statistically significant differences in the diagnostic accuracy between the original CT slice with HD and LD lesions viewed on the light box and on the 1K display workstation, the observers tended to record extra- axial lesions more frequently and with more confidence on the 1K display in comparison to the light box primarily due to the added advantage of adjusting the display window levels.

A diagnostic model for chronic hypersensitivity pneumonitis

PubMed Central

Johannson, Kerri A; Elicker, Brett M; Vittinghoff, Eric; Assayag, Deborah; de Boer, Kaïssa; Golden, Jeffrey A; Jones, Kirk D; King, Talmadge E; Koth, Laura L; Lee, Joyce S; Ley, Brett; Wolters, Paul J; Collard, Harold R

2017-01-01

The objective of this study was to develop a diagnostic model that allows for a highly specific diagnosis of chronic hypersensitivity pneumonitis using clinical and radiological variables alone. Chronic hypersensitivity pneumonitis and other interstitial lung disease cases were retrospectively identified from a longitudinal database. High-resolution CT scans were blindly scored for radiographic features (eg, ground-glass opacity, mosaic perfusion) as well as the radiologist’s diagnostic impression. Candidate models were developed then evaluated using clinical and radiographic variables and assessed by the cross-validated C-statistic. Forty-four chronic hypersensitivity pneumonitis and eighty other interstitial lung disease cases were identified. Two models were selected based on their statistical performance, clinical applicability and face validity. Key model variables included age, down feather and/or bird exposure, radiographic presence of ground-glass opacity and mosaic perfusion and moderate or high confidence in the radiographic impression of chronic hypersensitivity pneumonitis. Models were internally validated with good performance, and cut-off values were established that resulted in high specificity for a diagnosis of chronic hypersensitivity pneumonitis. PMID:27245779

Reliable Multi-Label Learning via Conformal Predictor and Random Forest for Syndrome Differentiation of Chronic Fatigue in Traditional Chinese Medicine

PubMed Central

Wang, Huazhen; Liu, Xin; Lv, Bing; Yang, Fan; Hong, Yanzhu

2014-01-01

Objective Chronic Fatigue (CF) still remains unclear about its etiology, pathophysiology, nomenclature and diagnostic criteria in the medical community. Traditional Chinese medicine (TCM) adopts a unique diagnostic method, namely ‘bian zheng lun zhi’ or syndrome differentiation, to diagnose the CF with a set of syndrome factors, which can be regarded as the Multi-Label Learning (MLL) problem in the machine learning literature. To obtain an effective and reliable diagnostic tool, we use Conformal Predictor (CP), Random Forest (RF) and Problem Transformation method (PT) for the syndrome differentiation of CF. Methods and Materials In this work, using PT method, CP-RF is extended to handle MLL problem. CP-RF applies RF to measure the confidence level (p-value) of each label being the true label, and then selects multiple labels whose p-values are larger than the pre-defined significance level as the region prediction. In this paper, we compare the proposed CP-RF with typical CP-NBC(Naïve Bayes Classifier), CP-KNN(K-Nearest Neighbors) and ML-KNN on CF dataset, which consists of 736 cases. Specifically, 95 symptoms are used to identify CF, and four syndrome factors are employed in the syndrome differentiation, including ‘spleen deficiency’, ‘heart deficiency’, ‘liver stagnation’ and ‘qi deficiency’. The Results CP-RF demonstrates an outstanding performance beyond CP-NBC, CP-KNN and ML-KNN under the general metrics of subset accuracy, hamming loss, one-error, coverage, ranking loss and average precision. Furthermore, the performance of CP-RF remains steady at the large scale of confidence levels from 80% to 100%, which indicates its robustness to the threshold determination. In addition, the confidence evaluation provided by CP is valid and well-calibrated. Conclusion CP-RF not only offers outstanding performance but also provides valid confidence evaluation for the CF syndrome differentiation. It would be well applicable to TCM practitioners and facilitate the utilities of objective, effective and reliable computer-based diagnosis tool. PMID:24918430

Predictors of physician confidence to diagnose pneumonia and determine illness severity in ventilated patients. Australian and New Zealand practice in intensive care (ANZPIC II).

PubMed

Boots, R J; Lipman, J; Bellomo, R; Stephens, D; Heller, R E

2005-02-01

The manner in which elements of clinical history, physical examination and investigations influence subjectively assessed illness severity and outcome prediction is poorly understood. This study investigates the relationship between clinician and objectively assessed illness severity and the factors influencing clinician's diagnostic confidence and illness severity rating for ventilated patients with suspected pneumonia in the intensive care unit (ICU). A prospective study of fourteen ICUs included all ventilated admissions with a clinical diagnosis of pneumonia. Data collection included pneumonia type - community-acquired (CAP), hospital-acquired (HAP) and ventilator-associated (VAP), clinician determined illness severity (CDIS), diagnostic methods, clinical diagnostic confidence (CDC), microbiological isolates and antibiotic use. For 476 episodes of pneumonia (48% CAP, 24% HAP, 28% VAP), CDC was greatest for CAP (64% CAP, 50% HAP and 49% VAP, P<0.01) or when pneumonia was considered "life-threatening" (84% high CDC, 13% medium CDC and 3% low CDC, P<0. 001). "Life-threatening" pneumonia was predicted by worsening gas exchange (OR 4.8, CI 95% 2.3-10.2, P<0.001), clinical signs of consolidation (OR 2.0, CI 95% 1.2-3.2, P<0.01) and the Sepsis-Related Organ Failure Assessment (SOFA) Score (OR 1.1, CI 95% 1.1-1.2, P<0.001). Diagnostic confidence increased with CDIS (OR 16.3, CI 95% 8.4-31.4, P<0.001), definite pathogen isolation (OR 3.3, CI 95% 2.0-5.6) and clinical signs of consolidation (OR 2.1, CI 95% 1.3-3.3, P=0.001). Although the CDIS, SOFA Score and the Simplified Acute Physiologic Score (SAPS II) were all associated with mortality, the SAPS II Score was the best predictor of mortality (P = 0. 02). Diagnostic confidence for pneumonia is moderate but increases with more classical presentations. A small set of clinical parameters influence subjective assessment. Objective assessment using SAPS II Scoring is a better predictor of mortality.

Making strides towards better mental health care in Peru: Results from a primary care mental health training

PubMed Central

Borba, C. P.C.; Gelaye, B.; Zayas, L.; Ulloa, M.; Lavelle, J.; Mollica, R.F.; Henderson, D.C.

2015-01-01

Our program attempted to improve attitudes and confidence of Peruvian primary care physicians (PCPs) providing mental health care. The training program underwent an evaluation to determine impact of sustained confidence in performing medical and psychiatric procedures, and application of learned skills. Fifty-two Peruvian primary care practitioners were trained at the Harvard Program in Refugee Trauma (HPRT) over a two-week period. There was significant improvement in PCPs’ confidence levels of performing psychiatric procedures (counseling, prescribing medications, psychiatric diagnosis, assessing the risk for violence, and treating trauma victims) when comparing baseline and post-two-week to one year follow-up. When comparing post-two-week and one-year follow-up quantitative measures, confidences levels went slightly down. This may be an implication that the frequency of trainings and supervisions are needed more frequently. In contrast, qualitative responses from the one-year follow-up revealed increase in victims of violence clinical care, advocacy, awareness, education, training, policy changes, accessibility of care, and sustainment of diagnostic tools. This study supports the feasibility of training PCP's in a culturally effective manner with sustainability over time. PMID:27054141

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

DNA-mounted self-assembly: new approaches for genomic analysis and SNP detection.

PubMed

Bichenkova, Elena V; Lang, Zhaolei; Yu, Xuan; Rogert, Candelaria; Douglas, Kenneth T

2011-01-01

This article presents an overview of new emerging approaches for nucleic acid detection via hybridization techniques that can potentially be applied to genomic analysis and SNP identification in clinical diagnostics. Despite the availability of a diverse variety of SNP genotyping technologies on the diagnostic market, none has truly succeeded in dominating its competitors thus far. Having been designed for specific diagnostic purposes or clinical applications, each of the existing bio-assay systems (briefly outlined here) is usually limited to a relatively narrow aspect or format of nucleic acid detection, and thus cannot entirely satisfy all the varieties of commercial requirements and clinical demands. This drives the diagnostic sector to pursue novel, cost-effective approaches to ensure rapid and reliable identification of pathogenic or hereditary human diseases. Hence, the purpose of this review is to highlight some new strategic directions in DNA detection technologies in order to inspire development of novel molecular diagnostic tools and bio-assay systems with superior reliability, reproducibility, robustness, accuracy and sensitivity at lower assay cost. One approach to improving the sensitivity of an assay to confidently discriminate between single point mutations is based on the use of target assembled, split-probe systems, which constitutes the main focus of this review. Copyright © 2010 Elsevier B.V. All rights reserved.

The diagnostic value of narrow-band imaging for early and invasive lung cancer: a meta-analysis.

PubMed

Zhu, Juanjuan; Li, Wei; Zhou, Jihong; Chen, Yuqing; Zhao, Chenling; Zhang, Ting; Peng, Wenjia; Wang, Xiaojing

2017-07-01

This study aimed to compare the ability of narrow-band imaging to detect early and invasive lung cancer with that of conventional pathological analysis and white-light bronchoscopy. We searched the PubMed, EMBASE, Sinomed, and China National Knowledge Infrastructure databases for relevant studies. Meta-disc software was used to perform data analysis, meta-regression analysis, sensitivity analysis, and heterogeneity testing, and STATA software was used to determine if publication bias was present, as well as to calculate the relative risks for the sensitivity and specificity of narrow-band imaging vs those of white-light bronchoscopy for the detection of early and invasive lung cancer. A random-effects model was used to assess the diagnostic efficacy of the above modalities in cases in which a high degree of between-study heterogeneity was noted with respect to their diagnostic efficacies. The database search identified six studies including 578 patients. The pooled sensitivity and specificity of narrow-band imaging were 86% (95% confidence interval: 83-88%) and 81% (95% confidence interval: 77-84%), respectively, and the pooled sensitivity and specificity of white-light bronchoscopy were 70% (95% confidence interval: 66-74%) and 66% (95% confidence interval: 62-70%), respectively. The pooled relative risks for the sensitivity and specificity of narrow-band imaging vs the sensitivity and specificity of white-light bronchoscopy for the detection of early and invasive lung cancer were 1.33 (95% confidence interval: 1.07-1.67) and 1.09 (95% confidence interval: 0.84-1.42), respectively, and sensitivity analysis showed that narrow-band imaging exhibited good diagnostic efficacy with respect to detecting early and invasive lung cancer and that the results of the study were stable. Narrow-band imaging was superior to white light bronchoscopy with respect to detecting early and invasive lung cancer; however, the specificities of the two modalities did not differ significantly.

Applicability and agreement of different diagnostic criteria for sarcopenia estimation in the elderly.

PubMed

Pagotto, Valéria; Silveira, Erika Aparecida

2014-01-01

The purpose of this study cross-sectional study comprising 132 community dwelling elderly (≥ 60 years) was to identify sarcopenia prevalence in the Brazilian elderly, utilizing different diagnostic criteria and analyze agreement between criteria. Sarcopenia was assessed by nine muscle mass diagnostic criteria, by two muscle strength criteria and also by the combination of criteria. Prevalence was analyzed for each method, along with differences by gender and age group through calculation of the prevalence ratio (PR) and confidence interval (CI) 95%. The Kappa coefficient was used to analyze the level of agreement between all criteria. Sarcopenia prevalence varied between 60.6% and 8.3% with the application of muscle mass criteria, and between 54.2% and 48.8% with the application of strength criteria. The combination muscle mass+strength resulted in a decrease of prevalence in all criteria, varying between 36.6% and 6.1%. There was an increase in prevalence according to age groups for all methods. Prevalence was higher for men according to three muscle mass criteria, and higher in women for strength criteria and by two combined mass+strength criteria. The best level of agreement was obtained for two methods that utilized dual energy X-ray absorptiometry (DXA). The prevalence of sarcopenia differs by gender and age and definition criteria. The low agreement levels obtained between methods and the different prevalence values encountered indicate the necessities of an operational definition for the estimation of sarcopenia in different population. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Differentiating Small (≤1 cm) Focal Liver Lesions as Metastases or Cysts by means of Computed Tomography: A Case-Study to Illustrate a Fuzzy Logic-Based Method to Assess the Impact of Diagnostic Confidence on Radiological Diagnosis

PubMed Central

Zanella, Gloria; Pullini, Serena; Como, Giuseppe; Bazzocchi, Massimo

2014-01-01

Purpose. To quantify the impact of diagnostic confidence on radiological diagnosis with a fuzzy logic-based method. Materials and Methods. Twenty-two oncologic patients with 20 cysts and 30 metastases ≤1 cm in size found at 64-row computed tomography were included. Two readers (R1/R2) expressed diagnoses as a subjective level of confidence P(d) in malignancy within the interval [0,1] rather than on a “crisp” basis (malignant/benign); confidence in benignancy was 1 − p(d). When cross-tabulating data according to the standard of reference, 2 × 2 table cells resulted from the aggregation between p(d)/1 − p(d) and final diagnosis. We then assessed (i) readers diagnostic performance on a fuzzy and crisp basis; (ii) the “divergence” δ(F, C) (%) as a measure of how confidence impacted on crisp diagnosis. Results. Diagnoses expressed with lower confidence increased fuzzy false positives compared to crisp ones (from 0 to 0.2 for R1; from 1 to 2.4 for R2). Crisp/fuzzy accuracy was 94.0%/93.6% (R1) and 94.0/91.6% (R2). δ(F, C) (%) was larger in the case of the less experienced reader (R2) (up to +7.95% for specificity). According to simulations, δ(F, C) (%) was negative/positive depending on the level of confidence in incorrect diagnoses. Conclusion. Fuzzy evaluation shows a measurable effect of uncertainty on radiological diagnoses. PMID:24587815

Off-site smartphone reading of CT images for patients with inconclusive diagnoses of appendicitis from on-call radiologists.

PubMed

Seong, Nak Jong; Kim, Bohyoung; Lee, Sungmin; Park, Hee Sun; Kim, Hyuk Jung; Woo, Hyunsik; Kang, Heung-Sik; Lee, Kyoung Ho

2014-07-01

The purpose of this study was to simulate a mobile consultation in patients with inconclusive diagnosis of appendicitis made by on-call radiologists, as well as to measure the diagnostic confidence and performance of the mobile consultation. Two off-site abdominal radiologists interpreted the CT images from 68 patients (including 29 patients with confirmed appendicitis) on a smart-phone for whom the preliminary CT reports by 25 in-house on-call radiologists were inconclusive. The smartphone readings were compared with the preliminary reports by on-call radiologists and with the original final reports by in-house abdominal radiologists. Heat maps, kappa statistics, Wilcoxon signed-rank tests, and ROC curves were used for data analysis. The heat maps and kappa statistics showed that the smartphone readings were more similar to the final reports than to the preliminary reports. In diagnosing or ruling out appendicitis, the smartphone readings were more confident than the preliminary reports (p ≤ 0.01) and did not significantly differ in diagnostic confidence from the final reports (p ≥ 0.19). The AUCs of the smartphone readings (0.91 and 0.92) did not differ significantly from those of the preliminary (0.85) or final (0.97) reports (p ≥ 0.09). With the given study sample, the diagnostic performance of the off-site smartphone readings did not differ significantly from that of the in-house preliminary reports. However, the smartphone readings provided higher diagnostic confidence than the preliminary reports.

Development and Comparison of Two Assay Formats for Parallel Detection of Four Biothreat Pathogens by Using Suspension Microarrays

PubMed Central

Janse, Ingmar; Bok, Jasper M.; Hamidjaja, Raditijo A.; Hodemaekers, Hennie M.; van Rotterdam, Bart J.

2012-01-01

Microarrays provide a powerful analytical tool for the simultaneous detection of multiple pathogens. We developed diagnostic suspension microarrays for sensitive and specific detection of the biothreat pathogens Bacillus anthracis, Yersinia pestis, Francisella tularensis and Coxiella burnetii. Two assay chemistries for amplification and labeling were developed, one method using direct hybridization and the other using target-specific primer extension, combined with hybridization to universal arrays. Asymmetric PCR products for both assay chemistries were produced by using a multiplex asymmetric PCR amplifying 16 DNA signatures (16-plex). The performances of both assay chemistries were compared and their advantages and disadvantages are discussed. The developed microarrays detected multiple signature sequences and an internal control which made it possible to confidently identify the targeted pathogens and assess their virulence potential. The microarrays were highly specific and detected various strains of the targeted pathogens. Detection limits for the different pathogen signatures were similar or slightly higher compared to real-time PCR. Probit analysis showed that even a few genomic copies could be detected with 95% confidence. The microarrays detected DNA from different pathogens mixed in different ratios and from spiked or naturally contaminated samples. The assays that were developed have a potential for application in surveillance and diagnostics. PMID:22355407

Development and Application of a Novel Rasch-based Methodology for Evaluating Multi-Tiered Assessment Instruments: Validation and utilization of an undergraduate diagnostic test of the water cycle

NASA Astrophysics Data System (ADS)

Romine, William L.; Schaffer, Dane L.; Barrow, Lloyd

2015-11-01

We describe the development and validation of a three-tiered diagnostic test of the water cycle (DTWC) and use it to evaluate the impact of prior learning experiences on undergraduates' misconceptions. While most approaches to instrument validation take a positivist perspective using singular criteria such as reliability and fit with a measurement model, we extend this to a multi-tiered approach which supports multiple interpretations. Using a sample of 130 undergraduate students from two colleges, we utilize the Rasch model to place students and items along traditional one-, two-, and three-tiered scales as well as a misconceptions scale. In the three-tiered and misconceptions scales, high confidence was indicative of mastery. In the latter scale, a 'misconception' was defined as mastery of an incorrect concept. We found that integrating confidence into mastery did little to change item functioning; however, three-tiered usage resulted in higher reliability and lower student ability estimates than two-tiered usage. The misconceptions scale showed high efficacy in predicting items on which particular students were likely to express misconceptions, and revealed several tenacious misconceptions that all students were likely to express regardless of ability. Previous coursework on the water cycle did little to change the prevalence of undergraduates' misconceptions.

Development and comparison of two assay formats for parallel detection of four biothreat pathogens by using suspension microarrays.

PubMed

Janse, Ingmar; Bok, Jasper M; Hamidjaja, Raditijo A; Hodemaekers, Hennie M; van Rotterdam, Bart J

2012-01-01

Microarrays provide a powerful analytical tool for the simultaneous detection of multiple pathogens. We developed diagnostic suspension microarrays for sensitive and specific detection of the biothreat pathogens Bacillus anthracis, Yersinia pestis, Francisella tularensis and Coxiella burnetii. Two assay chemistries for amplification and labeling were developed, one method using direct hybridization and the other using target-specific primer extension, combined with hybridization to universal arrays. Asymmetric PCR products for both assay chemistries were produced by using a multiplex asymmetric PCR amplifying 16 DNA signatures (16-plex). The performances of both assay chemistries were compared and their advantages and disadvantages are discussed. The developed microarrays detected multiple signature sequences and an internal control which made it possible to confidently identify the targeted pathogens and assess their virulence potential. The microarrays were highly specific and detected various strains of the targeted pathogens. Detection limits for the different pathogen signatures were similar or slightly higher compared to real-time PCR. Probit analysis showed that even a few genomic copies could be detected with 95% confidence. The microarrays detected DNA from different pathogens mixed in different ratios and from spiked or naturally contaminated samples. The assays that were developed have a potential for application in surveillance and diagnostics.

Parents' perceptions of tele-audiological testing in a rural hearing screening program in South India.

PubMed

Ramkumar, Vidya; Selvakumar, K; Vanaja, C S; Hall, James W; Nagarajan, Roopa; Neethi, J

2016-10-01

Tele-diagnostic audiological testing in a hearing screening program for infants and young children is a novel practice, and this study is the first to explore its application in a rural community. It is important to understand parental perceptions and confidence when introducing a new process such as tele-audiological diagnostic testing in rural areas. A questionnaire with 17 rater-administered items was designed to elicit comments concerning the quality of tele-hearing testing and video-conferencing, access to tele-hearing testing, and parents' attitudes regarding tele-hearing testing in the village. The questionnaire was administered by an audiologist not involved in tele-diagnostic testing to avoid bias. Parents perceived tele-hearing testing as equal in quality to in-person testing. Technical factors such as good video-conferencing quality and logistical factors such as ease of access due to reasonable travel time to testing facility could have influenced these perceptions. While these results show tele-hearing testing is an acceptable alternative, occasional poor signal quality should be addressed prior to large-scale implementation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Decision time and confidence predict choosers' identification performance in photographic showups

PubMed Central

Sagana, Anna; Sporer, Siegfried L.; Wixted, John T.

2018-01-01

In vast contrast to the multitude of lineup studies that report on the link between decision time, confidence, and identification accuracy, only a few studies looked at these associations for showups, with results varying widely across studies. We therefore set out to test the individual and combined value of decision time and post-decision confidence for diagnosing the accuracy of positive showup decisions using confidence-accuracy characteristic curves and Bayesian analyses. Three-hundred-eighty-four participants viewed a stimulus event and were subsequently presented with two showups which could be target-present or target-absent. As expected, we found a negative decision time-accuracy and a positive post-decision confidence-accuracy correlation for showup selections. Confidence-accuracy characteristic curves demonstrated the expected additive effect of combining both postdictors. Likewise, Bayesian analyses, taking into account all possible target-presence base rate values showed that fast and confident identification decisions were more diagnostic than slow or less confident decisions, with the combination of both being most diagnostic for postdicting accurate and inaccurate decisions. The postdictive value of decision time and post-decision confidence was higher when the prior probability that the suspect is the perpetrator was high compared to when the prior probability that the suspect is the perpetrator was low. The frequent use of showups in practice emphasizes the importance of these findings for court proceedings. Overall, these findings support the idea that courts should have most trust in showup identifications that were made fast and confidently, and least in showup identifications that were made slowly and with low confidence. PMID:29346394

Decision time and confidence predict choosers' identification performance in photographic showups.

PubMed

Sauerland, Melanie; Sagana, Anna; Sporer, Siegfried L; Wixted, John T

2018-01-01

In vast contrast to the multitude of lineup studies that report on the link between decision time, confidence, and identification accuracy, only a few studies looked at these associations for showups, with results varying widely across studies. We therefore set out to test the individual and combined value of decision time and post-decision confidence for diagnosing the accuracy of positive showup decisions using confidence-accuracy characteristic curves and Bayesian analyses. Three-hundred-eighty-four participants viewed a stimulus event and were subsequently presented with two showups which could be target-present or target-absent. As expected, we found a negative decision time-accuracy and a positive post-decision confidence-accuracy correlation for showup selections. Confidence-accuracy characteristic curves demonstrated the expected additive effect of combining both postdictors. Likewise, Bayesian analyses, taking into account all possible target-presence base rate values showed that fast and confident identification decisions were more diagnostic than slow or less confident decisions, with the combination of both being most diagnostic for postdicting accurate and inaccurate decisions. The postdictive value of decision time and post-decision confidence was higher when the prior probability that the suspect is the perpetrator was high compared to when the prior probability that the suspect is the perpetrator was low. The frequent use of showups in practice emphasizes the importance of these findings for court proceedings. Overall, these findings support the idea that courts should have most trust in showup identifications that were made fast and confidently, and least in showup identifications that were made slowly and with low confidence.

The role of computerized diagnostic proposals in the interpretation of the 12-lead electrocardiogram by cardiology and non-cardiology fellows.

PubMed

Novotny, Tomas; Bond, Raymond; Andrsova, Irena; Koc, Lumir; Sisakova, Martina; Finlay, Dewar; Guldenring, Daniel; Spinar, Jindrich; Malik, Marek

2017-05-01

Most contemporary 12-lead electrocardiogram (ECG) devices offer computerized diagnostic proposals. The reliability of these automated diagnoses is limited. It has been suggested that incorrect computer advice can influence physician decision-making. This study analyzed the role of diagnostic proposals in the decision process by a group of fellows of cardiology and other internal medicine subspecialties. A set of 100 clinical 12-lead ECG tracings was selected covering both normal cases and common abnormalities. A team of 15 junior Cardiology Fellows and 15 Non-Cardiology Fellows interpreted the ECGs in 3 phases: without any diagnostic proposal, with a single diagnostic proposal (half of them intentionally incorrect), and with four diagnostic proposals (only one of them being correct) for each ECG. Self-rated confidence of each interpretation was collected. Availability of diagnostic proposals significantly increased the diagnostic accuracy (p<0.001). Nevertheless, in case of a single proposal (either correct or incorrect) the increase of accuracy was present in interpretations with correct diagnostic proposals, while the accuracy was substantially reduced with incorrect proposals. Confidence levels poorly correlated with interpretation scores (rho≈2, p<0.001). Logistic regression showed that an interpreter is most likely to be correct when the ECG offers a correct diagnostic proposal (OR=10.87) or multiple proposals (OR=4.43). Diagnostic proposals affect the diagnostic accuracy of ECG interpretations. The accuracy is significantly influenced especially when a single diagnostic proposal (either correct or incorrect) is provided. The study suggests that the presentation of multiple computerized diagnoses is likely to improve the diagnostic accuracy of interpreters. Copyright © 2017 Elsevier B.V. All rights reserved.

The importance of quality assurance/quality control of diagnostics to increase the confidence in global foot-and-mouth disease control.

PubMed

De Clercq, K; Goris, N; Barnett, P V; MacKay, D K

2008-01-01

The last decade international trade in animals and animal products was liberated and confidence in this global trade can increase only if appropriate control measures are applied. As foot-and-mouth disease (FMD) diagnostics will play an essential role in this respect, the Food and Agriculture Organization European Commission for the Control of Foot-and-Mouth Disease (EUFMD) co-ordinates, in collaboration with the European Commission, several programmes to increase the quality of FMD diagnostics. A quality assurance (QA) system is deemed essential for laboratories involved in certifying absence of FMDV or antibodies against the virus. Therefore, laboratories are encouraged to validate their diagnostic tests fully and to install a continuous quality control (QC) monitoring system. Knowledge of performance characteristics of diagnostics is essential to interpret results correctly and to calculate sample rates in regional surveillance campaigns. Different aspects of QA/QC of classical and new FMD virological and serological diagnostics are discussed in respect to the EU FMD directive (2003/85/EC). We recommended accepting trade certificates only from laboratories participating in international proficiency testing on a regular basis.

Two Decades of WRF/CMAQ simulations over the continental ...

EPA Pesticide Factsheets

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 associated with modeled air quality concentrations. This paper presents novel approaches for performing dynamic model evaluation and for evaluating the confidence limits of ozone exceedances using the WRF/CMAQ model simulations over the continental United States for the period from 1990 to 2010. The methodology presented here entails spectral decomposition of ozone time series using the KZ filter to assess the variations in the strengths of the synoptic (i.e., weather-induced variation) and baseline (i.e., long-term variation attributable to emissions, policy, and trends) forcings embedded in the modeled and observed concentrations. A method is presented where the future year observations are estimated based on the changes in the concentrations predicted by the model applied to the current year observations. The proposed method can provide confidence limits for ozone exceedances for a given emission reduction scenario. We present and discuss these new approaches to identify the strengths of the model in representing the changes in simulated O3 air quality over the 21-year period. The National Exposure Research Laboratory (NERL) Computational Exposure Division (CED) develops and evaluates

Development of a framework for international certification by OIE of diagnostic tests validated as fit for purpose.

PubMed

Wright, P; Edwards, S; Diallo, A; Jacobson, R

2006-01-01

Historically, the OIE has focused on test methods applicable to trade and the international movement of animals and animal products. With its expanding role as the World Organisation for Animal Health, the OIE has recognised the need to evaluate test methods relative to specific diagnostic applications other than trade. In collaboration with its international partners, the OIE solicited input from experts through consultants' meetings on the development of guidelines for validation and certification of diagnostic assays for infectious animal diseases. Recommendations from the first meeting were formally adopted and have subsequently been acted upon by the OIE. A validation template has been developed that specifically requires a test to be fit or suited for its intended purpose (e.g. as a screening or a confirmatory test). This is a key criterion for validation. The template incorporates four distinct stages of validation, each of which has bearing on the evaluation of fitness for purpose. The OIE has just recently created a registry for diagnostic tests that fulfil these validation requirements. Assay developers are invited to submit validation dossiers to the OIE for evaluation by a panel of experts. Recognising that validation is an incremental process, tests methods achieving at least the first stages of validation may be provisionally accepted. To provide additional confidence in assay performance, the OIE, through its network of Reference Laboratories, has embarked on the development of evaluation panels. These panels would contain specially selected test samples that would assist in verifying fitness for purpose.

Development of a framework for international certification by the OIE of diagnostic tests validated as fit for purpose.

PubMed

Wright, P; Edwards, S; Diallo, A; Jacobson, R

2007-01-01

Historically, the OIE has focussed on test methods applicable to trade and the international movement of animals and animal products. With its expanding role as the World Organisation for Animal Health, the OIE has recognised the need to evaluate test methods relative to specific diagnostic applications other than trade. In collaboration with its international partners, the OIE solicited input from experts through consultants meetings on the development of guidelines for validation and certification of diagnostic assays for infectious animal diseases. Recommendations from the first meeting were formally adopted and have subsequently been acted upon by the OIE. A validation template has been developed that specifically requires a test to be fit or suited for its intended purpose (e.g. as a screening or a confirmatory test). This is a key criterion for validation. The template incorporates four distinct stages of validation, each of which has bearing on the evaluation of fitness for purpose. The OIE has just recently created a registry for diagnostic tests that fulfil these validation requirements. Assay developers are invited to submit validation dossiers to the OIE for evaluation by a panel of experts. Recognising that validation is an incremental process, tests methods achieving at least the first stages of validation may be provisionally accepted. To provide additional confidence in assay performance, the OIE, through its network of Reference Laboratories, has embarked on the development of evaluation panels. These panels would contain specially selected test samples that would assist in verifying fitness for purpose.

Evidence-based radiology: how to quickly assess the validity and strength of publications in the diagnostic radiology literature.

PubMed

Dodd, Jonathan D; MacEneaney, Peter M; Malone, Dermot E

2004-05-01

The aim of this study was to show how evidence-based medicine (EBM) techniques can be applied to the appraisal of diagnostic radiology publications. A clinical scenario is described: a gastroenterologist has questioned the diagnostic performance of magnetic resonance cholangiopancreatography (MRCP) in a patient who may have common bile duct (CBD) stones. His opinion was based on an article on MRCP published in "Gut." The principles of EBM are described and then applied to the critical appraisal of this paper. Another paper on the same subject was obtained from the radiology literature and was also critically appraised using explicit EBM criteria. The principles for assessing the validity and strength of both studies are outlined. All statistical parameters were generated quickly using a spreadsheet in Excel format. The results of EBM assessment of both papers are presented. The calculation and application of confidence intervals (CIs) and likelihood ratios (LRs) for both studies are described. These statistical results are applied to individual patient scenarios using graphs of conditional probability (GCP). Basic EBM principles are described and additional points relevant to radiologists discussed. Online resources for EBR practice are identified. The principles of EBM and their application to radiology are discussed. It is emphasized that sensitivity and specificity are point estimates of the "true" characteristics of a test in clinical practice. A spreadsheet can be used to quickly calculate CIs, LRs and GCPs. These give the radiologist a better understanding of the meaning of diagnostic test results in any patient or population of patients.

Confidence interval estimation of the difference between two sensitivities to the early disease stage.

PubMed

Dong, Tuochuan; Kang, Le; Hutson, Alan; Xiong, Chengjie; Tian, Lili

2014-03-01

Although most of the statistical methods for diagnostic studies focus on disease processes with binary disease status, many diseases can be naturally classified into three ordinal diagnostic categories, that is normal, early stage, and fully diseased. For such diseases, the volume under the ROC surface (VUS) is the most commonly used index of diagnostic accuracy. Because the early disease stage is most likely the optimal time window for therapeutic intervention, the sensitivity to the early diseased stage has been suggested as another diagnostic measure. For the purpose of comparing the diagnostic abilities on early disease detection between two markers, it is of interest to estimate the confidence interval of the difference between sensitivities to the early diseased stage. In this paper, we present both parametric and non-parametric methods for this purpose. An extensive simulation study is carried out for a variety of settings for the purpose of evaluating and comparing the performance of the proposed methods. A real example of Alzheimer's disease (AD) is analyzed using the proposed approaches. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A fast Monte Carlo EM algorithm for estimation in latent class model analysis with an application to assess diagnostic accuracy for cervical neoplasia in women with AGC

PubMed Central

Kang, Le; Carter, Randy; Darcy, Kathleen; Kauderer, James; Liao, Shu-Yuan

2013-01-01

In this article we use a latent class model (LCM) with prevalence modeled as a function of covariates to assess diagnostic test accuracy in situations where the true disease status is not observed, but observations on three or more conditionally independent diagnostic tests are available. A fast Monte Carlo EM (MCEM) algorithm with binary (disease) diagnostic data is implemented to estimate parameters of interest; namely, sensitivity, specificity, and prevalence of the disease as a function of covariates. To obtain standard errors for confidence interval construction of estimated parameters, the missing information principle is applied to adjust information matrix estimates. We compare the adjusted information matrix based standard error estimates with the bootstrap standard error estimates both obtained using the fast MCEM algorithm through an extensive Monte Carlo study. Simulation demonstrates that the adjusted information matrix approach estimates the standard error similarly with the bootstrap methods under certain scenarios. The bootstrap percentile intervals have satisfactory coverage probabilities. We then apply the LCM analysis to a real data set of 122 subjects from a Gynecologic Oncology Group (GOG) study of significant cervical lesion (S-CL) diagnosis in women with atypical glandular cells of undetermined significance (AGC) to compare the diagnostic accuracy of a histology-based evaluation, a CA-IX biomarker-based test and a human papillomavirus (HPV) DNA test. PMID:24163493

Diagnostics for a 1.2 kA, 1 MeV, electron induction injector

NASA Astrophysics Data System (ADS)

Houck, T. L.; Anderson, D. E.; Eylon, S.; Henestroza, E.; Lidia, S. M.; Vanecek, D. L.; Westenskow, G. A.; Yu, S. S.

1998-12-01

We are constructing a 1.2 kA, 1 MeV, electron induction injector as part of the RTA program, a collaborative effort between LLNL and LBNL to develop relativistic klystrons for Two-Beam Accelerator applications. The RTA injector will also be used in the development of a high-gradient, low-emittance, electron source and beam diagnostics for the second axis of the Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility. The electron source will be a 3.5″-diameter, thermionic, flat-surface, m-type cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 150 ns flat top (1% energy variation), and a normalized edge emittance of less than 200 π-mm-mr. Precise measurement of the beam parameters is required so that performance of the RTA injector can be confidently scaled to the 4 kA, 3 MeV, and 2-microsecond pulse parameters of the DARHT injector. Planned diagnostics include an isolated cathode with resistive divider for direct measurement of current emission, resistive wall and magnetic probe current monitors for measuring beam current and centroid position, capacitive probes for measuring A-K gap voltage, an energy spectrometer, and a pepperpot emittance diagnostic. Details of the injector, beam line, and diagnostics are presented.

Construction of joint confidence regions for the optimal true class fractions of Receiver Operating Characteristic (ROC) surfaces and manifolds.

PubMed

Bantis, Leonidas E; Nakas, Christos T; Reiser, Benjamin; Myall, Daniel; Dalrymple-Alford, John C

2017-06-01

The three-class approach is used for progressive disorders when clinicians and researchers want to diagnose or classify subjects as members of one of three ordered categories based on a continuous diagnostic marker. The decision thresholds or optimal cut-off points required for this classification are often chosen to maximize the generalized Youden index (Nakas et al., Stat Med 2013; 32: 995-1003). The effectiveness of these chosen cut-off points can be evaluated by estimating their corresponding true class fractions and their associated confidence regions. Recently, in the two-class case, parametric and non-parametric methods were investigated for the construction of confidence regions for the pair of the Youden-index-based optimal sensitivity and specificity fractions that can take into account the correlation introduced between sensitivity and specificity when the optimal cut-off point is estimated from the data (Bantis et al., Biomet 2014; 70: 212-223). A parametric approach based on the Box-Cox transformation to normality often works well while for markers having more complex distributions a non-parametric procedure using logspline density estimation can be used instead. The true class fractions that correspond to the optimal cut-off points estimated by the generalized Youden index are correlated similarly to the two-class case. In this article, we generalize these methods to the three- and to the general k-class case which involves the classification of subjects into three or more ordered categories, where ROC surface or ROC manifold methodology, respectively, is typically employed for the evaluation of the discriminatory capacity of a diagnostic marker. We obtain three- and multi-dimensional joint confidence regions for the optimal true class fractions. We illustrate this with an application to the Trail Making Test Part A that has been used to characterize cognitive impairment in patients with Parkinson's disease.

Validation of existing diagnosis of autism in mainland China using standardised diagnostic instruments.

PubMed

Sun, Xiang; Allison, Carrie; Auyeung, Bonnie; Zhang, Zhixiang; Matthews, Fiona E; Baron-Cohen, Simon; Brayne, Carol

2015-11-01

Research to date in mainland China has mainly focused on children with autistic disorder rather than Autism Spectrum Conditions and the diagnosis largely depended on clinical judgment without the use of diagnostic instruments. Whether children who have been diagnosed in China before meet the diagnostic criteria of Autism Spectrum Conditions is not known nor how many such children would meet these criteria. The aim of this study was to evaluate children with a known diagnosis of autism in mainland China using the Autism Diagnostic Observation Schedule and the Autism Diagnostic Interview-Revised to verify that children who were given a diagnosis of autism made by Chinese clinicians in China were mostly children with severe autism. Of 50 children with an existing diagnosis of autism made by Chinese clinicians, 47 children met the diagnosis of autism on the Autism Diagnostic Observation Schedule algorithm and 44 children met the diagnosis of autism on the Autism Diagnostic Interview-Revised algorithm. Using the Gwet's alternative chance-corrected statistic, the agreement between the Chinese diagnosis and the Autism Diagnostic Observation Schedule diagnosis was very good (AC1 = 0.94, p < 0.005, 95% confidence interval (0.86, 1.00)), so was the agreement between the Chinese diagnosis and the Autism Diagnostic Interview-Revised (AC1 = 0.91, p < 0.005, 95% confidence interval (0.81, 1.00)). The agreement between the Autism Diagnostic Observation Schedule and the Autism Diagnostic Interview-Revised was lower but still very good (AC1 = 0.83, p < 0.005). © The Author(s) 2015.

Validation of existing diagnosis of autism in mainland China using standardised diagnostic instruments

PubMed Central

Sun, Xiang; Allison, Carrie; Auyeung, Bonnie; Zhang, Zhixiang; Matthews, Fiona E; Baron-Cohen, Simon; Brayne, Carol

2016-01-01

Research to date in mainland China has mainly focused on children with autistic disorder rather than Autism Spectrum Conditions and the diagnosis largely depended on clinical judgment without the use of diagnostic instruments. Whether children who have been diagnosed in China before meet the diagnostic criteria of Autism Spectrum Conditions is not known nor how many such children would meet these criteria. The aim of this study was to evaluate children with a known diagnosis of autism in mainland China using the Autism Diagnostic Observation Schedule and the Autism Diagnostic Interview–Revised to verify that children who were given a diagnosis of autism made by Chinese clinicians in China were mostly children with severe autism. Of 50 children with an existing diagnosis of autism made by Chinese clinicians, 47 children met the diagnosis of autism on the Autism Diagnostic Observation Schedule algorithm and 44 children met the diagnosis of autism on the Autism Diagnostic Interview–Revised algorithm. Using the Gwet’s alternative chance-corrected statistic, the agreement between the Chinese diagnosis and the Autism Diagnostic Observation Schedule diagnosis was very good (AC1 = 0.94, p < 0.005, 95% confidence interval (0.86, 1.00)), so was the agreement between the Chinese diagnosis and the Autism Diagnostic Interview–Revised (AC1 = 0.91, p < 0.005, 95% confidence interval (0.81, 1.00)). The agreement between the Autism Diagnostic Observation Schedule and the Autism Diagnostic Interview–Revised was lower but still very good (AC1 = 0.83, p < 0.005). PMID:25757721

Student certainty answering misconception question: study of Three-Tier Multiple-Choice Diagnostic Test in Acid-Base and Solubility Equilibrium

NASA Astrophysics Data System (ADS)

Ardiansah; Masykuri, M.; Rahardjo, S. B.

2018-04-01

Students’ concept comprehension in three-tier multiple-choice diagnostic test related to student confidence level. The confidence level related to certainty and student’s self-efficacy. The purpose of this research was to find out students’ certainty in misconception test. This research was quantitative-qualitative research method counting students’ confidence level. The research participants were 484 students that were studying acid-base and equilibrium solubility subject. Data was collected using three-tier multiple-choice (3TMC) with thirty questions and students’ questionnaire. The findings showed that #6 item gives the highest misconception percentage and high student confidence about the counting of ultra-dilute solution’s pH. Other findings were that 1) the student tendency chosen the misconception answer is to increase over item number, 2) student certainty decreased in terms of answering the 3TMC, and 3) student self-efficacy and achievement were related each other in the research. The findings suggest some implications and limitations for further research.

Estimating the reliability of eyewitness identifications from police lineups

PubMed Central

Wixted, John T.; Mickes, Laura; Dunn, John C.; Clark, Steven E.; Wells, William

2016-01-01

Laboratory-based mock crime studies have often been interpreted to mean that (i) eyewitness confidence in an identification made from a lineup is a weak indicator of accuracy and (ii) sequential lineups are diagnostically superior to traditional simultaneous lineups. Largely as a result, juries are increasingly encouraged to disregard eyewitness confidence, and up to 30% of law enforcement agencies in the United States have adopted the sequential procedure. We conducted a field study of actual eyewitnesses who were assigned to simultaneous or sequential photo lineups in the Houston Police Department over a 1-y period. Identifications were made using a three-point confidence scale, and a signal detection model was used to analyze and interpret the results. Our findings suggest that (i) confidence in an eyewitness identification from a fair lineup is a highly reliable indicator of accuracy and (ii) if there is any difference in diagnostic accuracy between the two lineup formats, it likely favors the simultaneous procedure. PMID:26699467

Estimating the reliability of eyewitness identifications from police lineups.

PubMed

Wixted, John T; Mickes, Laura; Dunn, John C; Clark, Steven E; Wells, William

2016-01-12

Laboratory-based mock crime studies have often been interpreted to mean that (i) eyewitness confidence in an identification made from a lineup is a weak indicator of accuracy and (ii) sequential lineups are diagnostically superior to traditional simultaneous lineups. Largely as a result, juries are increasingly encouraged to disregard eyewitness confidence, and up to 30% of law enforcement agencies in the United States have adopted the sequential procedure. We conducted a field study of actual eyewitnesses who were assigned to simultaneous or sequential photo lineups in the Houston Police Department over a 1-y period. Identifications were made using a three-point confidence scale, and a signal detection model was used to analyze and interpret the results. Our findings suggest that (i) confidence in an eyewitness identification from a fair lineup is a highly reliable indicator of accuracy and (ii) if there is any difference in diagnostic accuracy between the two lineup formats, it likely favors the simultaneous procedure.

T1 and T2 mapping in myocarditis: seeing beyond the horizon of Lake Louise criteria and histopathology.

PubMed

Puntmann, Valentina O; Zeiher, Andreas M; Nagel, Eike

2018-05-01

Myocarditis and its sequelae remain an unconquered clinical problem, disproportionately affecting the young. Several hurdles beset myocarditis, including non-specific symptoms, heterogeneous clinical presentation, dynamic disease stages, underscored by an absence of an easy diagnostic test or a specific treatment. Areas covered: The current diagnostic means are poorly equipped to counter the challenge; the gold standard by invasive endomyocardial biopsy relies on availability of expert procedural and reading skill. The tissue diagnostic criteria were developed to improve readers agreement with clinical diagnosis, and not based on evidence for differential treatment or improved prognosis. The Lake-Louise Criteria represented a first step towards a non-invasive diagnosis. They require extensive imaging, which is insufficiently robust with poor diagnostic confidence and tissue pathophysiological validation; they similarly lack evidence of improved outcome by guiding clinical management. T1 and T2 mapping are a step-change, providing robust, short and quantifiable imaging application, which can veritably reflect the dynamic and heterogeneous underlying disease. Expert commentary: T1 and T2 mapping harbours a unique potential for an objective non-invasive disease recognition and treatment discovery in myocarditis. These measures should enter independently into clinical experimentation, with a high priority for outcome and therapeutic studies.

Clinical decision making using teleradiology in urology.

PubMed

Lee, B R; Allaf, M; Moore, R; Bohlman, M; Wang, G M; Bishoff, J T; Jackman, S V; Cadeddu, J A; Jarrett, T W; Khazan, R; Kavoussi, L R

1999-01-01

Using a personal computer-based teleradiology system, we compared accuracy, confidence, and diagnostic ability in the interpretation of digitized radiographs to determine if teleradiology-imported studies convey sufficient information to make relevant clinical decisions involving urology. Variables of diagnostic accuracy, confidence, image quality, interpretation, and the impact of clinical decisions made after viewing digitized radiographs were compared with those of original radiographs. We evaluated 956 radiographs that included 94 IV pyelograms, four voiding cystourethrograms, and two nephrostograms. The radiographs were digitized and transferred over an Ethernet network to a remote personal computer-based viewing station. The digitized images were viewed by urologists and graded according to confidence in making a diagnosis, image quality, diagnostic difficulty, clinical management based on the image itself, and brief patient history. The hard-copy radiographs were then interpreted immediately afterward, and diagnostic decisions were reassessed. All analog radiographs were reviewed by an attending radiologist. Ninety-seven percent of the decisions made from the digitized radiographs did not change after reviewing conventional radiographs of the same case. When comparing the variables of clinical confidence, quality of the film on the teleradiology system versus analog films, and diagnostic difficulty, we found no statistical difference (p > .05) between the two techniques. Overall accuracy in interpreting the digitized images on the teleradiology system was 88% by urologists compared with that of the attending radiologist's interpretation of the analog radiographs. However, urologists detected findings on five (5%) analog radiographs that had been previously unreported by the radiologist. Viewing radiographs transmitted to a personal computer-based viewing station is an appropriate means of reviewing films with sufficient quality on which to base clinical decisions. Our focus was whether decisions made after viewing the transmitted radiographs would change after viewing the hard-copy images of the same case. In 97% of the cases, the decision did not change. In those cases in which management was altered, recommendation of further imaging studies was the most common factor.

Directed Design of Experiments for Validating Probability of Detection Capability of NDE Systems (DOEPOD)

NASA Technical Reports Server (NTRS)

Generazio, Edward R.

2015-01-01

Directed Design of Experiments for Validating Probability of Detection Capability of NDE Systems (DOEPOD) Manual v.1.2 The capability of an inspection system is established by applications of various methodologies to determine the probability of detection (POD). One accepted metric of an adequate inspection system is that there is 95% confidence that the POD is greater than 90% (90/95 POD). Design of experiments for validating probability of detection capability of nondestructive evaluation (NDE) systems (DOEPOD) is a methodology that is implemented via software to serve as a diagnostic tool providing detailed analysis of POD test data, guidance on establishing data distribution requirements, and resolving test issues. DOEPOD demands utilization of observance of occurrences. The DOEPOD capability has been developed to provide an efficient and accurate methodology that yields observed POD and confidence bounds for both Hit-Miss or signal amplitude testing. DOEPOD does not assume prescribed POD logarithmic or similar functions with assumed adequacy over a wide range of flaw sizes and inspection system technologies, so that multi-parameter curve fitting or model optimization approaches to generate a POD curve are not required. DOEPOD applications for supporting inspector qualifications is included.

The PAPAS index: a novel index for the prediction of hepatitis C-related fibrosis.

PubMed

Ozel, Banu D; Poyrazoğlu, Orhan K; Karaman, Ahmet; Karaman, Hatice; Altinkaya, Engin; Sevinç, Eylem; Zararsiz, Gökmen

2015-08-01

Several noninvasive tests have been developed to determine the degree of hepatic fibrosis in patients with chronic hepatitis C (CHC) without performing liver biopsy. This study aimed to determine the performance of the PAPAS (Platelet/Age/Phosphatase/AFP/AST) index in patients with CHC for the prediction of significant fibrosis and cirrhosis and to compare it with other noninvasive tests. To date, no study has evaluated the application of the PAPAS index in CHC-associated liver fibrosis. This retrospective study included 137 consecutive patients with CHC who had undergone a percutaneous liver biopsy before treatment. The aspartate aminotransferase/platelet ratio (APRI), aspartate aminotransferase/alanine transaminase ratio (AAR), age-platelet index (API), FIB4, cirrhosis discriminate score (CDS), the Göteborg University cirrhosis index (GUCI), and PAPAS were calculated and compared with the diagnostic accuracies of all fibrosis indices between the groups F0-F2 (no-mild fibrosis) versus F3-F6 (significant fibrosis) and F0-F4 (no cirrhosis) versus F5-F6 (cirrhosis). To predict significant fibrosis, the area under curve (95% confidence interval) for FIB4 was 0.727 followed by GUCI (0.721), PAPAS≈APRI≈CDS (0.716), and API (0.68). To predict cirrhosis, the area under curve (95% confidence interval) for FIB4 was calculated to be 0.735, followed by GUCI (0.723), PAPAS≈APRI≈CDS≈(0.71), and API (0.66). No statistically significant difference was observed among these predictors to exclude both significant fibrosis and cirrhosis (P>0.05). The diagnostic capability of the PAPAS index has moderate efficiency and was not superior to other fibrosis markers for the identification of fibrosis in CHC patients. There is a need for more comprehensive prospective studies to help determine the diagnostic value of PAPAS for liver fibrosis.

Limitations of diagnostic precision and predictive utility in the individual case: a challenge for forensic practice.

PubMed

Cooke, David J; Michie, Christine

2010-08-01

Knowledge of group tendencies may not assist accurate predictions in the individual case. This has importance for forensic decision making and for the assessment tools routinely applied in forensic evaluations. In this article, we applied Monte Carlo methods to examine diagnostic agreement with different levels of inter-rater agreement given the distributional characteristics of PCL-R scores. Diagnostic agreement and score agreement were substantially less than expected. In addition, we examined the confidence intervals associated with individual predictions of violent recidivism. On the basis of empirical findings, statistical theory, and logic, we conclude that predictions of future offending cannot be achieved in the individual case with any degree of confidence. We discuss the problems identified in relation to the PCL-R in terms of the broader relevance to all instruments used in forensic decision making.

Diagnostic impact of digital tomosynthesis in oncologic patients with suspected pulmonary lesions on chest radiography.

PubMed

Quaia, Emilio; Baratella, Elisa; Poillucci, Gabriele; Gennari, Antonio Giulio; Cova, Maria Assunta

2016-08-01

To assess the actual diagnostic impact of digital tomosynthesis (DTS) in oncologic patients with suspected pulmonary lesions on chest radiography (CXR). A total of 237 patients (135 male, 102 female; age, 70.8 ± 10.4 years) with a known primary malignancy and suspected pulmonary lesion(s) on CXR and who underwent DTS were retrospectively identified. Two radiologists (experience, 10 and 15 years) analysed in consensus CXR and DTS images and proposed a diagnosis according to a confidence score: 1 or 2 = definitely or probably benign pulmonary or extrapulmonary lesion, or pseudolesion; 3 = indeterminate; 4 or 5 = probably or definitely pulmonary lesion. DTS findings were proven by CT (n = 114 patients), CXR during follow-up (n = 105) or histology (n = 18). Final diagnoses included 77 pulmonary opacities, 26 pulmonary scars, 12 pleural lesions and 122 pulmonary pseudolesions. DTS vs CXR presented a higher (P < 0.05) sensitivity (92 vs 15 %), specificity (91 vs 9 %), overall accuracy (92 vs 12 %), and diagnostic confidence (area under ROC, 0.997 vs 0.619). Mean effective dose of CXR vs DTS was 0.06 vs 0.107 mSv (P < 0.05). DTS improved diagnostic accuracy and confidence in comparison to CXR alone in oncologic patients with suspected pulmonary lesions on CXR with only a slight, though significant, increase in radiation dose. • Digital tomosynthesis (DTS) improves accuracy of chest radiography (CXR) in oncologic patients. • DTS improves confidence of CXR in oncologic patients. • DTS allowed avoidance of CT in about 50 % of oncologic patients.

Influence of reconstruction algorithms on image quality in SPECT myocardial perfusion imaging.

PubMed

Davidsson, Anette; Olsson, Eva; Engvall, Jan; Gustafsson, Agnetha

2017-11-01

We investigated if image- and diagnostic quality in SPECT MPI could be maintained despite a reduced acquisition time adding Depth Dependent Resolution Recovery (DDRR) for image reconstruction. Images were compared with filtered back projection (FBP) and iterative reconstruction using Ordered Subsets Expectation Maximization with (IRAC) and without (IRNC) attenuation correction (AC). Stress- and rest imaging for 15 min was performed on 21 subjects with a dual head gamma camera (Infinia Hawkeye; GE Healthcare), ECG-gating with 8 frames/cardiac cycle and a low-dose CT-scan. A 9 min acquisition was generated using five instead of eight gated frames and was reconstructed with DDRR, with (IRACRR) and without AC (IRNCRR) as well as with FBP. Three experienced nuclear medicine specialists visually assessed anonymized images according to eight criteria on a four point scale, three related to image quality and five to diagnostic confidence. Statistical analysis was performed using Visual Grading Regression (VGR). Observer confidence in statements on image quality was highest for the images that were reconstructed using DDRR (P<0·01 compared to FBP). Iterative reconstruction without DDRR was not superior to FBP. Interobserver variability was significant for statements on image quality (P<0·05) but lower in the diagnostic statements on ischemia and scar. The confidence in assessing ischemia and scar was not different between the reconstruction techniques (P = n.s.). SPECT MPI collected in 9 min, reconstructed with DDRR and AC, produced better image quality than the standard procedure. The observers expressed the highest diagnostic confidence in the DDRR reconstruction. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Simultaneous 11C-Methionine Positron Emission Tomography/Magnetic Resonance Imaging of Suspected Primary Brain Tumors

PubMed Central

Deuschl, Cornelius; Goericke, Sophia; Grueneisen, Johannes; Sawicki, Lino Morris; Goebel, Juliane; El Hindy, Nicolai; Wrede, Karsten; Binse, Ina; Poeppel, Thorsten; Quick, Harald; Forsting, Michael; Hense, Joerg; Umutlu, Lale; Schlamann, Marc

2016-01-01

Introduction The objective of this study was to assess the diagnostic value of integrated 11C- methionine PET/MRI for suspected primary brain tumors, in comparison to MRI alone. Material and Methods Forty-eight consecutive patients with suspected primary brain tumor were prospectively enrolled for an integrated 11C-methionine PET/MRI. Two neuro-radiologists separately evaluated the MRI alone and the integrated PET/MRI data sets regarding most likely diagnosis and diagnostic confidence on a 5-point scale. Reference standard was histopathology or follow-up imaging. Results Fifty-one suspicious lesions were detected: 16 high-grade glioma and 25 low-grade glioma. Ten non-malignant cerebral lesions were described by the reference standard. MRI alone and integrated PET/MRI each correctly classified 42 of the 51 lesions (82.4%) as neoplastic lesions (WHO grade II, III and IV) or non-malignant lesions (infectious and neoplastic lesions). Diagnostic confidence for all lesions, low-grade astrocytoma and high-grade astrocytoma (3.7 vs. 4.2, 3,1 vs. 3.8, 4.0 vs. 4,7) were significantly (p < 0.05) better with integrated PET/MRI than in MRI alone. Conclusions The present study demonstrates the high potential of integrated 11C-methionine-PET/MRI for the assessment of suspected primary brain tumors. Although integrated methionine PET/MRI does not lead to an improvement of correct diagnoses, diagnostic confidence is significantly improved. PMID:27907162

Response Latency as a Predictor of the Accuracy of Children's Reports

ERIC Educational Resources Information Center

Ackerman, Rakefet; Koriat, Asher

2011-01-01

Researchers have explored various diagnostic cues to the accuracy of information provided by child eyewitnesses. Previous studies indicated that children's confidence in their reports predicts the relative accuracy of these reports, and that the confidence-accuracy relationship generally improves as children grow older. In this study, we examined…

Evaluation of PET and MR datasets in integrated 18F-FDG PET/MRI: A comparison of different MR sequences for whole-body restaging of breast cancer patients.

PubMed

Grueneisen, Johannes; Sawicki, Lino Morris; Wetter, Axel; Kirchner, Julian; Kinner, Sonja; Aktas, Bahriye; Forsting, Michael; Ruhlmann, Verena; Umutlu, Lale

2017-04-01

To investigate the diagnostic value of different MR sequences and 18F-FDG PET data for whole-body restaging of breast cancer patients utilizing PET/MRI. A total of 36 patients with suspected tumor recurrence of breast cancer based on clinical follow-up or abnormal findings in follow-up examinations (e.g. CT, MRI) were prospectively enrolled in this study. All patients underwent a PET/CT and subsequently an additional PET/MR scan. Two readers were instructed to identify the occurrence of a tumor relapse in subsequent MR and PET/MR readings, utilizing different MR sequence constellations for each session. The diagnostic confidence for the determination of a malignant or benign lesion was qualitatively rated (3-point ordinal scale) for each lesion in the different reading sessions and the lesion conspicuity (4-point ordinal scale) for the three different MR sequences was additionally evaluated. Tumor recurrence was present in 25/36 (69%) patients. All three PET/MRI readings showed a significantly higher accuracy as well as higher confidence levels for the detection of recurrent breast cancer lesions when compared to MRI alone (p<0.05). Furthermore, all three PET/MR sequence constellations showed comparable diagnostic accuracy for the identification of a breast cancer recurrence (p>0.05), yet the highest confidence levels were obtained, when all three MR sequences were used for image interpretation. Moreover, contrast-enhanced T1-weighted VIBE imaging showed significantly higher values for the delineation of malignant and benign lesions when compared to T2w HASTE and diffusion-weighted imaging. Integrated PET/MRI provides superior restaging of breast cancer patients over MRI alone. Facing the need for appropriate and efficient whole-body PET/MR protocols, our results show the feasibility of fast and morphologically adequate PET/MR protocols. However, considering an equivalent accuracy for the detection of breast cancer recurrences in the three PET/MR readings, the application of contrast-agent and the inclusion of DWI in the study protocol seems to be debatable. Copyright © 2017 Elsevier B.V. All rights reserved.

Myocardial perfusion magnetic resonance imaging using sliding-window conjugate-gradient highly constrained back-projection reconstruction for detection of coronary artery disease.

PubMed

Ma, Heng; Yang, Jun; Liu, Jing; Ge, Lan; An, Jing; Tang, Qing; Li, Han; Zhang, Yu; Chen, David; Wang, Yong; Liu, Jiabin; Liang, Zhigang; Lin, Kai; Jin, Lixin; Bi, Xiaoming; Li, Kuncheng; Li, Debiao

2012-04-15

Myocardial perfusion magnetic resonance imaging (MRI) with sliding-window conjugate-gradient highly constrained back-projection reconstruction (SW-CG-HYPR) allows whole left ventricular coverage, improved temporal and spatial resolution and signal/noise ratio, and reduced cardiac motion-related image artifacts. The accuracy of this technique for detecting coronary artery disease (CAD) has not been determined in a large number of patients. We prospectively evaluated the diagnostic performance of myocardial perfusion MRI with SW-CG-HYPR in patients with suspected CAD. A total of 50 consecutive patients who were scheduled for coronary angiography with suspected CAD underwent myocardial perfusion MRI with SW-CG-HYPR at 3.0 T. The perfusion defects were interpreted qualitatively by 2 blinded observers and were correlated with x-ray angiographic stenoses ≥50%. The prevalence of CAD was 56%. In the per-patient analysis, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of SW-CG-HYPR was 96% (95% confidence interval 82% to 100%), 82% (95% confidence interval 60% to 95%), 87% (95% confidence interval 70% to 96%), 95% (95% confidence interval 74% to100%), and 90% (95% confidence interval 82% to 98%), respectively. In the per-vessel analysis, the corresponding values were 98% (95% confidence interval 91% to 100%), 89% (95% confidence interval 80% to 94%), 86% (95% confidence interval 76% to 93%), 99% (95% confidence interval 93% to 100%), and 93% (95% confidence interval 89% to 97%), respectively. In conclusion, myocardial perfusion MRI using SW-CG-HYPR allows whole left ventricular coverage and high resolution and has high diagnostic accuracy in patients with suspected CAD. Copyright © 2012 Elsevier Inc. All rights reserved.

Nonportable computed radiography of the chest--radiologists' acceptance

NASA Astrophysics Data System (ADS)

Gennari, Rose C.; Gur, David; Miketic, Linda M.; Campbell, William L.; Oliver, James H., III; Plunkett, Michael B.

1994-04-01

Following a large ROC study to assess diagnostic accuracy of PA chest computed radiography (CR) images displayed in a variety of formats, we asked nine experienced radiologists to subjectively assess their acceptance of and preferences for display modes in primary diagnosis of erect PA chest images. Our results indicate that radiologists felt somewhat less comfortable interpreting CR images displayed on either laser-printed films or workstations as compared to conventional films. The use of four minified images were thought to somewhat decrease diagnostic confidence, as well as to increase the time of interpretation. The reverse mode (black bone) images increased radiologists' confidence level in the detection of soft tissue abnormalities.

The Effects of Diagnostic Definitions in Claims Data on Healthcare Cost Estimates: Evidence from a Large-Scale Panel Data Analysis of Diabetes Care in Japan.

PubMed

Fukuda, Haruhisa; Ikeda, Shunya; Shiroiwa, Takeru; Fukuda, Takashi

2016-10-01

Inaccurate estimates of diabetes-related healthcare costs can undermine the efficiency of resource allocation for diabetes care. The quantification of these costs using claims data may be affected by the method for defining diagnoses. The aims were to use panel data analysis to estimate diabetes-related healthcare costs and to comparatively evaluate the effects of diagnostic definitions on cost estimates. Monthly panel data analysis of Japanese claims data. The study included a maximum of 141,673 patients with type 2 diabetes who received treatment between 2005 and 2013. Additional healthcare costs associated with diabetes and diabetes-related complications were estimated for various diagnostic definition methods using fixed-effects panel data regression models. The average follow-up period per patient ranged from 49.4 to 52.3 months. The number of patients identified as having type 2 diabetes varied widely among the diagnostic definition methods, ranging from 14,743 patients to 141,673 patients. The fixed-effects models showed that the additional costs per patient per month associated with diabetes ranged from US$180 [95 % confidence interval (CI) 178-181] to US$223 (95 % CI 221-224). When the diagnostic definition excluded rule-out diagnoses, the diabetes-related complications associated with higher additional healthcare costs were ischemic heart disease with surgery (US$13,595; 95 % CI 13,568-13,622), neuropathy/extremity disease with surgery (US$4594; 95 % CI 3979-5208), and diabetic nephropathy with dialysis (US$3689; 95 % CI 3667-3711). Diabetes-related healthcare costs are sensitive to diagnostic definition methods. Determining appropriate diagnostic definitions can further advance healthcare cost research for diabetes and its applications in healthcare policies.

Enabling digital pathology in the diagnostic setting: navigating through the implementation journey in an academic medical centre.

PubMed

Cheng, Chee Leong; Azhar, Rafay; Sng, Shi Hui Adeline; Chua, Yong Quan; Hwang, Jacqueline Siok Gek; Chin, Jennifer Poi Fun; Seah, Waih Khuen; Loke, Janel Chui Ling; Ang, Roy Hang Leng; Tan, Puay Hoon

2016-09-01

As digital pathology (DP) and whole slide imaging (WSI) technology advance and mature, there is an increasing drive to incorporate DP into the diagnostic environment. However, integration of DP into the diagnostic laboratory is a non-trivial task and filled with unexpected challenges unlike standalone implementations. We share our journey of implementing DP in the diagnostic laboratory setting, highlighting seven key guiding principles that drive the progression through implementation into deployment and beyond. The DP implementation with laboratory information system integration was completed in 8 months, including validation of the solution for diagnostic use in accordance with College of American Pathologists guidelines. We also conducted prospective validation via paired delivery of glass slides and WSI to our pathologists postdeployment. Common themes in our guiding principles included emphasis on workflow and being comprehensive in the approach, looking beyond pathologist user champions and expanding into an extended project team involving laboratory technicians, clerical/data room staff and archival staff. Concordance between glass slides and WSI ranged from 93% to 100% among various applications on validation. We also provided equal opportunities for every pathologist throughout the department to be competent and confident with DP through prospective validation, with overall concordance of 96% compared with glass slides, allowing appreciation of the advantages and limitations of WSI, hence enabling the use of DP as a useful diagnostic modality. Smooth integration of DP into the diagnostic laboratory is possible with careful planning, discipline and a systematic approach adhering to our guiding principles. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

A diagnostic model for chronic hypersensitivity pneumonitis.

PubMed

Johannson, Kerri A; Elicker, Brett M; Vittinghoff, Eric; Assayag, Deborah; de Boer, Kaïssa; Golden, Jeffrey A; Jones, Kirk D; King, Talmadge E; Koth, Laura L; Lee, Joyce S; Ley, Brett; Wolters, Paul J; Collard, Harold R

2016-10-01

The objective of this study was to develop a diagnostic model that allows for a highly specific diagnosis of chronic hypersensitivity pneumonitis using clinical and radiological variables alone. Chronic hypersensitivity pneumonitis and other interstitial lung disease cases were retrospectively identified from a longitudinal database. High-resolution CT scans were blindly scored for radiographic features (eg, ground-glass opacity, mosaic perfusion) as well as the radiologist's diagnostic impression. Candidate models were developed then evaluated using clinical and radiographic variables and assessed by the cross-validated C-statistic. Forty-four chronic hypersensitivity pneumonitis and eighty other interstitial lung disease cases were identified. Two models were selected based on their statistical performance, clinical applicability and face validity. Key model variables included age, down feather and/or bird exposure, radiographic presence of ground-glass opacity and mosaic perfusion and moderate or high confidence in the radiographic impression of chronic hypersensitivity pneumonitis. Models were internally validated with good performance, and cut-off values were established that resulted in high specificity for a diagnosis of chronic hypersensitivity pneumonitis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Diagnostic Accuracy of Imaging Modalities and Injection Techniques for the Diagnosis of Femoroacetabular Impingement/Labral Tear: A Systematic Review With Meta-analysis.

PubMed

Reiman, Michael P; Thorborg, Kristian; Goode, Adam P; Cook, Chad E; Weir, Adam; Hölmich, Per

2017-09-01

Diagnosing femoroacetabular impingement/acetabular labral tear (FAI/ALT) and subsequently making a decision regarding surgery are based primarily on diagnostic imaging and intra-articular hip joint injection techniques of unknown accuracy. Summarize and evaluate the diagnostic accuracy and clinical utility of various imaging modalities and injection techniques relevant to hip FAI/ALT. Systematic review with meta-analysis. A computer-assisted literature search was conducted of MEDLINE, CINAHL, and EMBASE databases using keywords related to diagnostic accuracy of hip joint pathologic changes. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were used for the search and reporting phases of the study. Quality assessment of bias and applicability was conducted using the Quality of Diagnostic Accuracy Studies (QUADAS) tool. Random effects models were used to summarize sensitivities (SN), specificities (SP), likelihood ratios (+LR and -LR), diagnostic odds ratios (DOR), and respective confidence intervals (CI). The search strategy and assessment for risk of bias revealed 25 articles scoring above 10/14 on the items of the QUADAS. Four studies investigated FAI, and the data were not pooled. Twenty articles on ALT qualified for meta-analysis. Pretest probability of ALT in the studies in this review was 81% (72%-88%), while the pretest probability of FAI diagnosis was 74% (95% CI, 51%-91%). The meta-analysis showed that computed tomography arthrography (CTA) demonstrated the strongest overall diagnostic accuracy: pooled SN 0.91 (95% CI, 0.83-0.96); SP 0.89 (95% CI, 0.74-0.97); +LR 6.28 (95% CI, 2.78-14.21); -LR 0.11 (95% CI, 0.06-0.21); and DOR 64.38 (95% CI, 19.17-216.21). High pretest probability of disease was demonstrated. Positive imaging findings increased the probability that a labral tear existed by a minimal to small degree with the use of magnetic resonance imaging/magnetic resonance angiogram (MRI/MRA) and ultrasound (US) and by a moderate degree for CTA. Negative imaging findings decreased the probability that a labral tear existed by a minimal degree with the use of MRI and US, a small to moderate degree with MRA, and a moderate degree with CTA. Although findings of the included studies suggested potentially favorable use of these modalities for the diagnosis of ALT and FAI, our results suggest that these findings have limited generalizability and clinical utility given very high pretest prevalence, large confidence intervals, and selection criteria of the studies. Registration: PROSPERO Registration #CRD42015027745.

Sensor Data Qualification for Autonomous Operation of Space Systems

NASA Technical Reports Server (NTRS)

Maul, William A.; Melcher, Kevin J.; Chicatelli, Amy K.; Sowers, T. Shane

2006-01-01

NASA's new Exploration initiative for both robotic and manned missions will require higher levels of reliability, autonomy and reconfiguration capability to make the missions safe, successful and affordable. Future systems will require diagnostic reasoning to assess the health of the system in order to maintain the system s functionality. The diagnostic reasoning and assessment will involve data qualification, fault detection, fault isolation and remediation control. A team of researchers at the NASA Glenn Research Center is currently working on a Sensor Data Qualification (SDQ) system that will support these critical evaluation processes, for both automated and human-in-the-loop applications. Data qualification is required as a first step so that critical safety and operational decisions are based on good data. The SDQ system would monitor a network of related sensors to determine the health of individual sensors within that network. Various diagnostic systems such as the Caution and Warning System would then use the sensor health information with confidence. The proposed SDQ technology will be demonstrated on a variety of subsystems that are relevant to NASA s Exploration systems, which currently include an electrical power system and a cryogenic fluid management system. The focus of this paper is the development and demonstration of a SDQ application for a prototype power distribution unit that is representative of a Crew Exploration Vehicle electrical power system; this provides a unique and relevant environment in which to demonstrate the feasibility of the SDQ technology.

Extensions to decision curve analysis, a novel method for evaluating diagnostic tests, prediction models and molecular markers

PubMed Central

Vickers, Andrew J; Cronin, Angel M; Elkin, Elena B; Gonen, Mithat

2008-01-01

Background Decision curve analysis is a novel method for evaluating diagnostic tests, prediction models and molecular markers. It combines the mathematical simplicity of accuracy measures, such as sensitivity and specificity, with the clinical applicability of decision analytic approaches. Most critically, decision curve analysis can be applied directly to a data set, and does not require the sort of external data on costs, benefits and preferences typically required by traditional decision analytic techniques. Methods In this paper we present several extensions to decision curve analysis including correction for overfit, confidence intervals, application to censored data (including competing risk) and calculation of decision curves directly from predicted probabilities. All of these extensions are based on straightforward methods that have previously been described in the literature for application to analogous statistical techniques. Results Simulation studies showed that repeated 10-fold crossvalidation provided the best method for correcting a decision curve for overfit. The method for applying decision curves to censored data had little bias and coverage was excellent; for competing risk, decision curves were appropriately affected by the incidence of the competing risk and the association between the competing risk and the predictor of interest. Calculation of decision curves directly from predicted probabilities led to a smoothing of the decision curve. Conclusion Decision curve analysis can be easily extended to many of the applications common to performance measures for prediction models. Software to implement decision curve analysis is provided. PMID:19036144

Extensions to decision curve analysis, a novel method for evaluating diagnostic tests, prediction models and molecular markers.

PubMed

Vickers, Andrew J; Cronin, Angel M; Elkin, Elena B; Gonen, Mithat

2008-11-26

Decision curve analysis is a novel method for evaluating diagnostic tests, prediction models and molecular markers. It combines the mathematical simplicity of accuracy measures, such as sensitivity and specificity, with the clinical applicability of decision analytic approaches. Most critically, decision curve analysis can be applied directly to a data set, and does not require the sort of external data on costs, benefits and preferences typically required by traditional decision analytic techniques. In this paper we present several extensions to decision curve analysis including correction for overfit, confidence intervals, application to censored data (including competing risk) and calculation of decision curves directly from predicted probabilities. All of these extensions are based on straightforward methods that have previously been described in the literature for application to analogous statistical techniques. Simulation studies showed that repeated 10-fold crossvalidation provided the best method for correcting a decision curve for overfit. The method for applying decision curves to censored data had little bias and coverage was excellent; for competing risk, decision curves were appropriately affected by the incidence of the competing risk and the association between the competing risk and the predictor of interest. Calculation of decision curves directly from predicted probabilities led to a smoothing of the decision curve. Decision curve analysis can be easily extended to many of the applications common to performance measures for prediction models. Software to implement decision curve analysis is provided.

Diagnostic accuracy of intracellular mycobacterium tuberculosis detection for tuberculous meningitis.

PubMed

Feng, Guo-dong; Shi, Ming; Ma, Lei; Chen, Ping; Wang, Bing-ju; Zhang, Min; Chang, Xiao-lin; Su, Xiu-chu; Yang, Yi-ning; Fan, Xin-hong; Dai, Wen; Liu, Ting-ting; He, Ying; Bian, Ting; Duan, Li-xin; Li, Jin-ge; Hao, Xiao-ke; Liu, Jia-yun; Xue, Xin; Song, Yun-zhang; Wu, Hai-qin; Niu, Guo-qiang; Zhang, Li; Han, Cui-juan; Lin, Hong; Lin, Zhi-hui; Liu, Jian-jun; Jian, Qian; Zhang, Jin-she; Tian, Ye; Zhou, Bai-yu; Wang, Jing; Xue, Chang-hu; Han, Xiao-fang; Wang, Jian-feng; Wang, Shou-lian; Thwaites, Guy E; Zhao, Gang

2014-02-15

Early diagnosis and treatment of tuberculous meningitis saves lives, but current laboratory diagnostic tests lack sensitivity. We investigated whether the detection of intracellular bacteria by a modified Ziehl-Neelsen stain and early secretory antigen target (ESAT)-6 in cerebrospinal fluid leukocytes improves tuberculous meningitis diagnosis. Cerebrospinal fluid specimens from patients with suspected tuberculous meningitis were stained by conventional Ziehl-Neelsen stain, a modified Ziehl-Neelsen stain involving cytospin slides with Triton processing, and an ESAT-6 immunocytochemical stain. Acid-fast bacteria and ESAT-6-expressing leukocytes were detected by microscopy. All tests were performed prospectively in a central laboratory by experienced technicians masked to the patients' final diagnosis. Two hundred and eighty patients with suspected tuberculous meningitis were enrolled. Thirty-seven had Mycobacterium tuberculosis cultured from cerebrospinal fluid; 40 had a microbiologically confirmed alternative diagnosis; the rest had probable or possible tuberculous meningitis according to published criteria. Against a clinical diagnostic gold standard the sensitivity of conventional Ziehl-Neelsen stain was 3.3% (95% confidence interval, 1.6-6.7%), compared with 82.9% (95% confidence interval, 77.4-87.3%) for modified Ziehl-Neelsen stain and 75.1% (95% confidence interval, 68.8-80.6%) for ESAT-6 immunostain. Intracellular bacteria were seen in 87.8% of the slides positive by the modified Ziehl-Neelsen stain. The specificity of modified Ziehl-Neelsen and ESAT-6 stain was 85.0% (95% confidence interval, 69.4-93.8%) and 90.0% (95% confidence interval, 75.4-96.7%), respectively. Enhanced bacterial detection by simple modification of the Ziehl-Neelsen stain and an ESAT-6 intracellular stain improve the laboratory diagnosis of tuberculous meningitis.

Transient Elastography vs. Aspartate Aminotransferase to Platelet Ratio Index in Hepatitis C: A Meta-Analysis.

PubMed

Mattos, A Z; Mattos, A A

Many different non-invasive methods have been studied with the purpose of staging liver fibrosis. The objective of this study was verifying if transient elastography is superior to aspartate aminotransferase to platelet ratio index for staging fibrosis in patients with chronic hepatitis C. A systematic review with meta-analysis of studies which evaluated both non-invasive tests and used biopsy as the reference standard was performed. A random-effects model was used, anticipating heterogeneity among studies. Diagnostic odds ratio was the main effect measure, and summary receiver operating characteristic curves were created. A sensitivity analysis was planned, in which the meta-analysis would be repeated excluding each study at a time. Eight studies were included in the meta-analysis. Regarding the prediction of significant fibrosis, transient elastography and aspartate aminotransferase to platelet ratio index had diagnostic odds ratios of 11.70 (95% confidence interval = 7.13-19.21) and 8.56 (95% confidence interval = 4.90-14.94) respectively. Concerning the prediction of cirrhosis, transient elastography and aspartate aminotransferase to platelet ratio index had diagnostic odds ratios of 66.49 (95% confidence interval = 23.71-186.48) and 7.47 (95% confidence interval = 4.88-11.43) respectively. In conclusion, there was no evidence of significant superiority of transient elastography over aspartate aminotransferase to platelet ratio index regarding the prediction of significant fibrosis, but the former proved to be better than the latter concerning prediction of cirrhosis.

An Interview with Medical Diagnostics Scientist Bernhard Weigl

ERIC Educational Resources Information Center

Sullivan, Megan

2010-01-01

Medical diagnostics help us evaluate a range of disorders, such as cancer and infectious diseases. In the United States and other developed countries, doctors have access to advanced equipment and laboratories that provide reliable diagnoses. As a result, when we are sick, we feel confident that we will get the treatment we need. Unfortunately,…

Yield of diagnostic tests for celiac disease in individuals with symptoms suggestive of irritable bowel syndrome: systematic review and meta-analysis.

PubMed

Ford, Alexander C; Chey, William D; Talley, Nicholas J; Malhotra, Ashish; Spiegel, Brennan M R; Moayyedi, Paul

2009-04-13

Individuals with irritable bowel syndrome (IBS) report abdominal pain, bloating, and diarrhea, symptoms similar to those in celiac disease. Studies suggest that the prevalence of celiac disease is increased in individuals with IBS; however, evidence is conflicting, and current guidelines do not always recommend screening for celiac disease in these individuals. We conducted a systematic review and meta-analysis to estimate prevalence of celiac disease in unselected adults who met diagnostic criteria for IBS. MEDLINE (1950 to May 31, 2008) and EMBASE (1980 to May 31, 2008) were searched. Case series and case-control studies that used serologic tests for celiac disease were eligible for inclusion. Prevalence of positive serologic indications of celiac disease and biopsy-proved celiac disease were extracted and pooled for all studies and were compared between cases and controls using an odds ratio and 95% confidence interval. Fourteen studies were identified comprising 4204 individuals, of whom 2278 (54%) met diagnostic criteria for IBS. Pooled prevalence of positive IgA-class antigliadin antibodies, either positive endomysial antibodies or tissue transglutaminase, and biopsy-proved celiac disease were 4.0% (95% confidence interval, 1.7-7.2), 1.63% (0.7-3.0), and 4.1% (1.9-7.0), respectively. Pooled odds ratios (95% confidence intervals) for positive IgA-class antigliadin antibodies, either positive endomysial antibodies or tissue transglutaminase, and biopsy-proved celiac disease in cases meeting diagnostic criteria for IBS compared with controls without IBS were 3.40 (1.62-7.13), 2.94 (1.36-6.35), and 4.34 (1.78-10.6). Prevalence of biopsy-proved celiac disease in cases meeting diagnostic criteria for IBS was more than 4-fold that in controls without IBS.

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.

Practical application of contrast-enhanced magnetic resonance mammography [CE-MRM] by an algorithm combining morphological and enhancement patterns.

PubMed

Potente, Giuseppe; Messineo, Daniela; Maggi, Claudia; Savelli, Sara

2009-03-01

The purpose of this article is to report our practical utilization of dynamic contrast-enhanced magnetic resonance mammography [DCE-MRM] in the diagnosis of breast lesions. In many European centers, was preferred a high-temporal acquisition of both breasts simultaneously in a large FOV. We preferred to scan single breasts, with the aim to combine the analysis of the contrast intake and washout with the morphological evaluation of breast lesions. We followed an interpretation model, based upon a diagnostic algorithm, which combined contrast enhancement with morphological evaluation, in order to increase our confidence in diagnosis. DCE-MRM with our diagnostic algorithm has identified 179 malignant and 41 benign lesions; final outcome has identified 178 malignant and 42 benign lesions, 3 false positives and 2 false negatives. Sensitivity of CE-MRM was 98.3%; specificity, 95.1%; positive predictive value, 98.9%; negative predictive value, 92.8% and accuracy, 97.7%.

Review of the Global Models Used Within Phase 1 of the Chemistry-Climate Model Initiative (CCMI)

NASA Technical Reports Server (NTRS)

Morgenstern, Olaf; Hegglin, Michaela I.; Rozanov, Eugene; O’Connor, Fiona M.; Abraham, N. Luke; Akiyoshi, Hideharu; Archibald, Alexander T.; Bekki, Slimane; Butchart, Neal; Chipperfield, Martyn P.;

Characterization of trabecular bone using the backscattered spectral centroid shift.

PubMed

Wear, Keith A

2003-04-01

Ultrasonic attenuation in bone in vivo is generally measured using a through-transmission method at the calcaneus. Although attenuation in calcaneus has been demonstrated to be a useful predictor for osteoporotic fracture risk, measurements at other clinically important sites, such as hip and spine, could potentially contain additional useful diagnostic information. Through-transmission measurements may not be feasible at these sites due to complex bone shapes and the increased amount of intervening soft tissue. Centroid shift from the backscattered signal is an index of attenuation slope and has been used previously to characterize soft tissues. In this paper, centroid shift from signals backscattered from 30 trabecular bone samples in vitro were measured. Attenuation slope also was measured using a through-transmission method. The correlation coefficient between centroid shift and attenuation slope was -0.71. The 95% confidence interval was (-0.86, -0.47). These results suggest that the backscattered spectral centroid shift may contain useful diagnostic information potentially applicable to hip and spine.

Comparison of Diagnostic Accuracy of Clinical Measures of Breast Cancer–Related Lymphedema: Area Under the Curve

PubMed Central

Smoot, Betty J.; Wong, Josephine F.; Dodd, Marylin J.

2013-01-01

Objective To compare diagnostic accuracy of measures of breast cancer–related lymphedema (BCRL). Design Cross-sectional design comparing clinical measures with the criterion standard of previous diagnosis of BCRL. Setting University of California San Francisco Translational Science Clinical Research Center. Participants Women older than 18 years and more than 6 months posttreatment for breast cancer (n=141; 70 with BCRL, 71 without BCRL). Interventions Not applicable. Main Outcome Measures Sensitivity, specificity, receiver operator characteristic curve, and area under the curve (AUC) were used to evaluate accuracy. Results A total of 141 women were categorized as having (n=70) or not having (n=71) BCRL based on past diagnosis by a health care provider, which was used as the reference standard. Analyses of ROC curves for the continuous outcomes yielded AUC of .68 to .88 (P<.001); of the physical measures bioimpedance spectroscopy yielded the highest accuracy with an AUC of .88 (95% confidence interval, .80–.96) for women whose dominant arm was the affected arm. The lowest accuracy was found using the 2-cm diagnostic cutoff score to identify previously diagnosed BCRL (AUC, .54–.65). Conclusions Our findings support the use of bioimpedance spectroscopy in the assessment of existing BCRL. Refining diagnostic cutoff values may improve accuracy of diagnosis and warrant further investigation. PMID:21440706

Impact of molecular imaging on the diagnostic process in a memory clinic.

PubMed

Ossenkoppele, Rik; Prins, Niels D; Pijnenburg, Yolande A L; Lemstra, Afina W; van der Flier, Wiesje M; Adriaanse, Sofie F; Windhorst, Albert D; Handels, Ron L H; Wolfs, Claire A G; Aalten, Pauline; Verhey, Frans R J; Verbeek, Marcel M; van Buchem, Mark A; Hoekstra, Otto S; Lammertsma, Adriaan A; Scheltens, Philip; van Berckel, Bart N M

2013-07-01

[(11)C]Pittsburgh compound B ([(11)C]PIB) and [(18)F]-2-fluoro-2-deoxy-D-glucose ([(18)F]FDG) PET measure fibrillar amyloid-β load and glucose metabolism, respectively. We evaluated the impact of these tracers on the diagnostic process in a memory clinic population. One hundred fifty-four patients underwent paired dynamic [(11)C]PIB and static [(18)F]FDG PET scans shortly after completing a standard dementia screening. Two-year clinical follow-up data were available for 39 patients. Parametric PET images were assessed visually and results were reported to the neurologists responsible for the initial diagnosis. Outcome measures were (change in) clinical diagnosis and confidence in that diagnosis before and after disclosing PET results. [(11)C]PIB scans were positive in 40 of 66 (61%) patients with a clinical diagnosis of Alzheimer's disease (AD), 5 of 18 (28%) patients with frontotemporal dementia (FTD), 4 of 5 (80%) patients with Lewy body dementia, and 3 of 10 (30%) patients with other dementias. [(18)F]FDG uptake patterns matched the clinical diagnosis in 38 of 66 (58%) of AD patients, and in 6 of 18 (33%) FTD patients. PET results led to a change in diagnosis in 35 (23%) patients. This only occurred when prior diagnostic certainty was <90%. Diagnostic confidence increased from 71 ± 17% before to 87 ± 16% after PET (p < .001). Two-year clinical follow-up (n = 39) showed that [(11)C]PIB and [(18)F]FDG predicted progression to AD for patients with mild cognitive impairment, and that the diagnosis of dementia established after PET remained unchanged in 96% of patients. In a memory clinic setting, combined [(11)C]PIB and [(18)F]FDG PET are of additional value on top of the standard diagnostic work-up, especially when prior diagnostic confidence is low. Copyright © 2013 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

Sensitivity and specificity of proposed DSM-5 diagnostic criteria for autism spectrum disorder Running Head: DSM-5 ASD

PubMed Central

McPartland, James C.; Reichow, Brian; Volkmar, Fred R.

2012-01-01

Objective This study evaluated the potential impact of proposed DSM-5 diagnostic criteria for autism spectrum disorder (ASD). Method This study focused on a sample of 977 participants evaluated during the DSM-IV field trial; 657 carried a clinical diagnosis of an ASD, and 276 were diagnosed with a non-autistic disorder. Sensitivity and specificity for proposed DSM-5 diagnostic criteria were evaluated using field trial symptom checklists as follows: (a) individual field trial checklist items (e.g., nonverbal communication), (b) checklist items grouped together as described by a single DSM-5 symptom (e.g., nonverbal and verbal communication), (c) individual DSM-5 criterion (e.g., social-communicative impairment), and (d) overall diagnostic criteria. Results When applying proposed DSM-5 diagnostic criteria for ASD, 60.6% (95% confidence interval: 57–64%) of cases with a clinical diagnosis of an ASD met revised DSM-5 diagnostic criteria for ASD. Overall specificity was high, with 94.9% (95% confidence interval: 92–97%) of individuals accurately excluded from the spectrum. Sensitivity varied by diagnostic subgroup (Autistic Disorder =.76; Asperger’s Disorder = .25; PDD-NOS = .28) and cognitive ability (IQ < 70 = .70; IQ ≥ 70 = .46). Conclusions Proposed DSM-5 criteria substantially alter the composition of the autism spectrum. Revised criteria improve specificity, but exclude a substantial portion of cognitively able individuals and those with ASDs other than Autistic Disorder. A more stringent diagnostic rubric holds significant public health ramifications regarding service eligibility and compatibility of historical and future research. PMID:22449643

Reliability of clinical findings and magnetic resonance imaging for the diagnosis of chondromalacia patellae.

PubMed

Pihlajamäki, Harri K; Kuikka, Paavo-Ilari; Leppänen, Vesa-Veikko; Kiuru, Martti J; Mattila, Ville M

2010-04-01

This diagnostic study was performed to determine the correlation between anterior knee pain and chondromalacia patellae and to define the reliability of magnetic resonance imaging for the diagnosis of chondromalacia patellae. Fifty-six young adults (median age, 19.5 years) with anterior knee pain had magnetic resonance imaging of the knee followed by arthroscopy. The patellar chondral lesions identified by magnetic resonance imaging were compared with the arthroscopic findings. Arthroscopy confirmed the presence of chondromalacia patellae in twenty-five (45%) of the fifty-six knees, a synovial plica in twenty-five knees, a meniscal tear in four knees, and a femorotibial chondral lesion in four knees; normal anatomy was seen in six knees. No association was found between the severity of the chondromalacia patellae seen at arthroscopy and the clinical symptoms of anterior knee pain syndrome (p = 0.83). The positive predictive value for the ability of 1.0-T magnetic resonance imaging to detect chondromalacia patellae was 75% (95% confidence interval, 53% to 89%), the negative predictive value was 72% (95% confidence interval, 56% to 84%), the sensitivity was 60% (95% confidence interval, 41% to 77%), the specificity was 84% (95% confidence interval, 67% to 93%), and the diagnostic accuracy was 73% (95% confidence interval, 60% to 83%). The sensitivity was 13% (95% confidence interval, 2% to 49%) for grade-I lesions and 83% (95% confidence interval, 59% to 94%) for grade-II, III, or IV lesions. Chondromalacia patellae cannot be diagnosed on the basis of symptoms or with current physical examination methods. The present study demonstrated no correlation between the severity of chondromalacia patellae and the clinical symptoms of anterior knee pain syndrome. Thus, symptoms of anterior knee pain syndrome should not be used as an indication for knee arthroscopy. The sensitivity of 1.0-T magnetic resonance imaging was low for grade-I lesions but considerably higher for more severe (grade-II, III, or IV) lesions. Magnetic resonance imaging may be considered an accurate diagnostic tool for identification of more severe cases of chondromalacia patellae.

[Diagnostic imaging and acute abdominal pain].

PubMed

Liljekvist, Mads Svane; Pommergaard, Hans-Christian; Burcharth, Jakob; Rosenberg, Jacob

2015-01-19

Acute abdominal pain is a common clinical condition. Clinical signs and symptoms can be difficult to interpret, and diagnostic imaging may help to identify intra-abdominal disease. Conventional X-ray, ultrasound (US) and computed tomography (CT) of the abdomen vary in usability between common surgical causes of acute abdominal pain. Overall, conventional X-ray cannot confidently diagnose or rule out disease. US and CT are equally trustworthy for most diseases. US with subsequent CT may enhance diagnostic precision. Magnetic resonance seems promising for future use in acute abdominal imaging.

The confidence-accuracy relationship in eyewitness identification: effects of lineup instructions, foil similarity, and target-absent base rates.

PubMed

Brewer, Neil; Wells, Gary L

2006-03-01

Discriminating accurate from mistaken eyewitness identifications is a major issue facing criminal justice systems. This study examined whether eyewitness confidence assists such decisions under a variety of conditions using a confidence-accuracy (CA) calibration approach. Participants (N = 1,200) viewed a simulated crime and attempted 2 separate identifications from 8-person target-present or target-absent lineups. Confidence and accuracy were calibrated for choosers (but not nonchoosers) for both targets under all conditions. Lower overconfidence was associated with higher diagnosticity, lower target-absent base rates, and shorter identification latencies. Although researchers agree that courtroom expressions of confidence are uninformative, our findings indicate that confidence assessments obtained immediately after a positive identification can provide a useful guide for investigators about the likely accuracy of an identification.

Application of tissue mesodissection to molecular cancer diagnostics.

PubMed

Krizman, David; Adey, Nils; Parry, Robert

2015-02-01

To demonstrate clinical application of a mesodissection platform that was developed to combine advantages of laser-based instrumentation with the speed/ease of manual dissection for automated dissection of tissue off standard glass slides. Genomic analysis for KRAS gene mutation was performed on formalin fixed paraffin embedded (FFPE) cancer patient tissue that was dissected using the mesodissection platform. Selected reaction monitoring proteomic analysis for quantitative Her2 protein expression was performed on FFPE patient tumour tissue dissected by a laser-based instrument and the MilliSect instrument. Genomic analysis demonstrates highly confident detection of KRAS mutation specifically in lung cancer cells and not the surrounding benign, non-tumour tissue. Proteomic analysis demonstrates Her2 quantitative protein expression in breast cancer cells dissected manually, by laser-based instrumentation and by MilliSect instrumentation (mesodissection). Slide-mounted tissue dissection is commonly performed using laser-based instruments or manually scraping tissue by scalpel. Here we demonstrate that the mesodissection platform as performed by the MilliSect instrument for tissue dissection is cost-effective; it functions comparably to laser-based dissection and which can be adopted into a clinical diagnostic workflow. 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.

Readout-segmented multi-shot diffusion-weighted MRI of the knee joint in patients with juvenile idiopathic arthritis.

PubMed

Sauer, Alexander; Li, Mengxia; Holl-Wieden, Annette; Pabst, Thomas; Neubauer, Henning

2017-10-12

Diffusion-weighted MRI has been proposed as a new technique for imaging synovitis without intravenous contrast application. We investigated diagnostic utility of multi-shot readout-segmented diffusion-weighted MRI (multi-shot DWI) for synovial imaging of the knee joint in patients with juvenile idiopathic arthritis (JIA). Thirty-two consecutive patients with confirmed or suspected JIA (21 girls, median age 13 years) underwent routine 1.5 T MRI with contrast-enhanced T1w imaging (contrast-enhanced MRI) and with multi-shot DWI (RESOLVE, b-values 0-50 and 800 s/mm 2 ). Contrast-enhanced MRI, representing the diagnostic standard, and diffusion-weighted images at b = 800 s/mm 2 were separately rated by three independent blinded readers at different levels of expertise for the presence and the degree of synovitis on a modified 5-item Likert scale along with the level of subjective diagnostic confidence. Fourteen (44%) patients had active synovitis and joint effusion, nine (28%) patients showed mild synovial enhancement not qualifying for arthritis and another nine (28%) patients had no synovial signal alterations on contrast-enhanced imaging. Ratings by the 1st reader on contrast-enhanced MRI and on DWI showed substantial agreement (κ = 0.74). Inter-observer-agreement was high for diagnosing, or ruling out, active arthritis of the knee joint on contrast-enhanced MRI and on DWI, showing full agreement between 1st and 2nd reader and disagreement in one case (3%) between 1st and 3rd reader. In contrast, ratings in cases of absent vs. little synovial inflammation were markedly inconsistent on DWI. Diagnostic confidence was lower on DWI, compared to contrast-enhanced imaging. Multi-shot DWI of the knee joint is feasible in routine imaging and reliably diagnoses, or rules out, active arthritis of the knee joint in paediatric patients without the need of gadolinium-based i.v. contrast injection. Possibly due to "T2w shine-through" artifacts, DWI does not reliably differentiate non-inflamed joints from knee joints with mild synovial irritation.

Smartphone-Based Fluorescent Diagnostic System for Highly Pathogenic H5N1 Viruses.

PubMed

Yeo, Seon-Ju; Choi, Kyunghan; Cuc, Bui Thi; Hong, Nguyen Ngoc; Bao, Duong Tuan; Ngoc, Nguyen Minh; Le, Mai Quynh; Hang, Nguyen Le Khanh; Thach, Nguyen Co; Mallik, Shyam Kumar; Kim, Hak Sung; Chong, Chom-Kyu; Choi, Hak Soo; Sung, Haan Woo; Yu, Kyoungsik; Park, Hyun

2016-01-01

Field diagnostic tools for avian influenza (AI) are indispensable for the prevention and controlled management of highly pathogenic AI-related diseases. More accurate, faster and networked on-site monitoring is demanded to detect such AI viruses with high sensitivity as well as to maintain up-to-date information about their geographical transmission. In this work, we assessed the clinical and field-level performance of a smartphone-based fluorescent diagnostic device with an efficient reflective light collection module using a coumarin-derived dendrimer-based fluorescent lateral flow immunoassay. By application of an optimized bioconjugate, a smartphone-based diagnostic device had a two-fold higher detectability as compared to that of the table-top fluorescence strip reader for three different AI subtypes (H5N3, H7N1, and H9N2). Additionally, in a clinical study of H5N1-confirmed patients, the smartphone-based diagnostic device showed a sensitivity of 96.55% (28/29) [95% confidence interval (CI): 82.24 to 99.91] and a specificity of 98.55% (68/69) (95% CI: 92.19 to 99.96). The measurement results from the distributed individual smartphones were wirelessly transmitted via short messaging service and collected by a centralized database system for further information processing and data mining. Smartphone-based diagnosis provided highly sensitive measurement results for H5N1 detection within 15 minutes. Because of its high sensitivity, portability and automatic reporting feature, the proposed device will enable agile identification of patients and efficient control of AI dissemination.

Smartphone-Based Fluorescent Diagnostic System for Highly Pathogenic H5N1 Viruses

PubMed Central

Yeo, Seon-Ju; Choi, Kyunghan; Cuc, Bui Thi; Hong, Nguyen Ngoc; Bao, Duong Tuan; Ngoc, Nguyen Minh; Le, Mai Quynh; Hang, Nguyen Le Khanh; Thach, Nguyen Co; Mallik, Shyam Kumar; Kim, Hak Sung; Chong, Chom-Kyu; Choi, Hak Soo; Sung, Haan Woo; Yu, Kyoungsik; Park, Hyun

2016-01-01

Field diagnostic tools for avian influenza (AI) are indispensable for the prevention and controlled management of highly pathogenic AI-related diseases. More accurate, faster and networked on-site monitoring is demanded to detect such AI viruses with high sensitivity as well as to maintain up-to-date information about their geographical transmission. In this work, we assessed the clinical and field-level performance of a smartphone-based fluorescent diagnostic device with an efficient reflective light collection module using a coumarin-derived dendrimer-based fluorescent lateral flow immunoassay. By application of an optimized bioconjugate, a smartphone-based diagnostic device had a two-fold higher detectability as compared to that of the table-top fluorescence strip reader for three different AI subtypes (H5N3, H7N1, and H9N2). Additionally, in a clinical study of H5N1-confirmed patients, the smartphone-based diagnostic device showed a sensitivity of 96.55% (28/29) [95% confidence interval (CI): 82.24 to 99.91] and a specificity of 98.55% (68/69) (95% CI: 92.19 to 99.96). The measurement results from the distributed individual smartphones were wirelessly transmitted via short messaging service and collected by a centralized database system for further information processing and data mining. Smartphone-based diagnosis provided highly sensitive measurement results for H5N1 detection within 15 minutes. Because of its high sensitivity, portability and automatic reporting feature, the proposed device will enable agile identification of patients and efficient control of AI dissemination. PMID:26877781

Tracing the decision-making process of physicians with a Decision Process Matrix.

PubMed

Hausmann, Daniel; Zulian, Cristina; Battegay, Edouard; Zimmerli, Lukas

2016-10-18

Decision-making processes in a medical setting are complex, dynamic and under time pressure, often with serious consequences for a patient's condition. The principal aim of the present study was to trace and map the individual diagnostic process of real medical cases using a Decision Process Matrix [DPM]). The naturalistic decision-making process of 11 residents and a total of 55 medical cases were recorded in an emergency department, and a DPM was drawn up according to a semi-structured technique following four steps: 1) observing and recording relevant information throughout the entire diagnostic process, 2) assessing options in terms of suspected diagnoses, 3) drawing up an initial version of the DPM, and 4) verifying the DPM, while adding the confidence ratings. The DPM comprised an average of 3.2 suspected diagnoses and 7.9 information units (cues). The following three-phase pattern could be observed: option generation, option verification, and final diagnosis determination. Residents strove for the highest possible level of confidence before making the final diagnoses (in two-thirds of the medical cases with a rating of practically certain) or excluding suspected diagnoses (with practically impossible in half of the cases). The following challenges have to be addressed in the future: real-time capturing of emerging suspected diagnoses in the memory of the physician, definition of meaningful information units, and a more contemporary measurement of confidence. DPM is a useful tool for tracing real and individual diagnostic processes. The methodological approach with DPM allows further investigations into the underlying cognitive diagnostic processes on a theoretical level and improvement of individual clinical reasoning skills in practice.

Systematic Review and Meta-Analysis of CT Features for Differentiating Complicated and Uncomplicated Appendicitis.

PubMed

Kim, Hae Young; Park, Ji Hoon; Lee, Yoon Jin; Lee, Sung Soo; Jeon, Jong-June; Lee, Kyoung Ho

2018-04-01

Purpose To perform a systematic review and meta-analysis to identify computed tomographic (CT) features for differentiating complicated appendicitis in patients suspected of having appendicitis and to summarize their diagnostic accuracy. Materials and Methods Studies on diagnostic accuracy of CT features for differentiating complicated appendicitis (perforated or gangrenous appendicitis) in patients suspected of having appendicitis were searched in Ovid-MEDLINE, EMBASE, and the Cochrane Library. Overlapping descriptors used in different studies to denote the same image finding were subsumed under a single CT feature. Pooled diagnostic accuracy of the CT features was calculated by using a bivariate random effects model. CT features with pooled diagnostic odds ratios with 95% confidence intervals not including 1 were considered as informative. Results Twenty-three studies were included, and 184 overlapping descriptors for various CT findings were subsumed under 14 features. Of these, 10 features were informative for complicated appendicitis. There was a general tendency for these features to show relatively high specificity but low sensitivity. Extraluminal appendicolith, abscess, appendiceal wall enhancement defect, extraluminal air, ileus, periappendiceal fluid collection, ascites, intraluminal air, and intraluminal appendicolith showed pooled specificity greater than 70% (range, 74%-100%), but sensitivity was limited (range, 14%-59%). Periappendiceal fat stranding was the only feature that showed high sensitivity (94%; 95% confidence interval: 86%, 98%) but low specificity (40%; 95% confidence interval, 23%, 60%). Conclusion Ten informative CT features for differentiating complicated appendicitis were identified in this study, nine of which showed high specificity, but low sensitivity. © RSNA, 2017 Online supplemental material is available for this article.

Dental Faculty Accuracy When Using Diagnostic Codes: A Pilot Study.

PubMed

Sutton, Jeanne C; Fay, Rose-Marie; Huynh, Carolyn P; Johnson, Cleverick D; Zhu, Liang; Quock, Ryan L

2017-05-01

The aim of this study was to examine the accuracy of dental faculty members' utilization of diagnostic codes and resulting treatment planning based on radiographic interproximal tooth radiolucencies. In 2015, 50 full-time and part-time general dentistry faculty members at one U.S. dental school were shown a sequence of 15 bitewing radiographs; one interproximal radiolucency was highlighted on each bitewing. For each radiographic lesion, participants were asked to choose the most appropriate diagnostic code (from a concise list of five codes, corresponding to lesion progression to outer/inner halves of enamel and outer/middle/pulpal thirds of dentin), acute treatment (attempt to arrest/remineralize non-invasively, operative intervention, or no treatment), and level of confidence in choices. Diagnostic and treatment choices of participants were compared to "gold standard" correct responses, as determined by expert radiology and operative faculty members, respectively. The majority of the participants selected the correct diagnostic code for lesions in the outer one-third of dentin (p<0.0001) and the pulpal one-third of dentin (p<0.0001). For lesions in the outer and inner halves of enamel and the middle one-third of dentin, the correct rates were moderate. However, the majority of the participants chose correct treatments on all types of lesions (correct rate 63.6-100%). Faculty members' confidence in their responses was generally high for all lesions, all above 90%. Diagnostic codes were appropriately assigned by participants for the very deepest lesions, but they were not assigned accurately for more incipient lesions (limited to enamel). Paradoxically, treatment choices were generally correct, regardless of diagnostic choices. Further calibration is needed to improve faculty use and teaching of diagnostic codes.

Validation of Digital Microscopy Compared With Light Microscopy for the Diagnosis of Canine Cutaneous Tumors.

PubMed

Bertram, Christof A; Gurtner, Corinne; Dettwiler, Martina; Kershaw, Olivia; Dietert, Kristina; Pieper, Laura; Pischon, Hannah; Gruber, Achim D; Klopfleisch, Robert

2018-07-01

Integration of new technologies, such as digital microscopy, into a highly standardized laboratory routine requires the validation of its performance in terms of reliability, specificity, and sensitivity. However, a validation study of digital microscopy is currently lacking in veterinary pathology. The aim of the current study was to validate the usability of digital microscopy in terms of diagnostic accuracy, speed, and confidence for diagnosing and differentiating common canine cutaneous tumor types and to compare it to classical light microscopy. Therefore, 80 histologic sections including 17 different skin tumor types were examined twice as glass slides and twice as digital whole-slide images by 6 pathologists with different levels of experience at 4 time points. Comparison of both methods found digital microscopy to be noninferior for differentiating individual tumor types within the category epithelial and mesenchymal tumors, but diagnostic concordance was slightly lower for differentiating individual round cell tumor types by digital microscopy. In addition, digital microscopy was associated with significantly shorter diagnostic time, but diagnostic confidence was lower and technical quality was considered inferior for whole-slide images compared with glass slides. Of note, diagnostic performance for whole-slide images scanned at 200× magnification was noninferior in diagnostic performance for slides scanned at 400×. In conclusion, digital microscopy differs only minimally from light microscopy in few aspects of diagnostic performance and overall appears adequate for the diagnosis of individual canine cutaneous tumors with minor limitations for differentiating individual round cell tumor types and grading of mast cell tumors.

Efficacy and safety of cryobiopsy versus forceps biopsy for interstitial lung diseases and lung tumours: A systematic review and meta-analysis.

PubMed

Ganganah, Oormila; Guo, Shu Liang; Chiniah, Manu; Li, Yi Shi

2016-07-01

Forceps biopsy (FB) is the most commonly used diagnostic tool for lung pathologies. FB is associated with a high diagnostic failure rate. Cryobiopsy (CB) is a novel technique providing a larger specimen size, few artefacts, more alveolar parts and superior diagnostic yield. CB, however, has drawbacks such as higher bleeding and pneumothorax rate. We conducted a meta-analysis to investigate the specimen area, diagnostic rate and bleeding severity in CB versus FB in interstitial lung diseases (ILDs) and lung tumours. A systematic literature search of PUBMED, BIOSIS PREVIEW and OVID databases was conducted using specific search terms. Eligible studies including RCTs and non-RCTs comparing cryobiopsy/cryotransbronchial biopsy (CB/CTBB) and forceps biopsy/forceps transbronchial biopsy (FB/FTBB) for specimen area, diagnostic rate and bleeding rate in ILDs and lung tumours were analysed. Two reviewers independently extracted data and evaluated the quality of the studies. Eight studies involving 916 patients were analysed. Specimen area (mm(2) ) was significantly larger in CB/CTBB than FB/FTBB (standard mean difference = 1.21, 95% confidence interval (0.94, 1.48), P < 0.00001). The diagnostic rate was significantly higher in CB/CTBB than FB/FTBB (Risk ratio 1.36, 95% confidence interval (1.16, 1.59), P = 0.0002). Three studies compared the bleeding severity with only one showing significantly more bleeding in CB. Cryobiopsy/cryotransbronchial shows superiority to FB/FTBB for specimen area and diagnostic rate. CB/CTBB has better efficacy over FB/FTBB. © 2016 Asian Pacific Society of Respirology.

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

DIAGNOSIS OF ENDOCRINE DISEASE: High-yield thyroid fine-needle aspiration cytology: an update focused on ancillary techniques improving its accuracy.

PubMed

Bongiovanni, M; Trimboli, P; Rossi, E D; Fadda, G; Nobile, A; Giovanella, L

2016-02-01

Thyroid fine-needle aspiration (FNA) cytology is a fast growing field. One of the most developing areas is represented by molecular tests applied to cytological material. Patients that could benefit the most from these tests are those that have been diagnosed as 'indeterminate' on FNA. They could be better stratified in terms of malignancy risk and thus oriented with more confidence to the appropriate management. Taking in to consideration the need to improve and keep high the yield of thyroid FNA, professionals from various fields (i.e. molecular biologists, endocrinologists, nuclear medicine physicians and radiologists) are refining and fine-tuning their diagnostic instruments. In particular, all these developments aim at increasing the negative predictive value of FNA to improve the selection of patients for diagnostic surgery. These advances involve terminology, the application of next-generation sequencing to thyroid FNA, the use of immunocyto- and histo-chemistry, the development of new sampling techniques and the increasing use of nuclear medicine as well as molecular imaging in the management of patients with a thyroid nodule. Herein, we review the recent advances in thyroid FNA cytology that could be of interest to the 'thyroid-care' community, with particular focus on the indeterminate diagnostic category. © 2016 European Society of Endocrinology.

The learning curve, interobserver, and intraobserver agreement of endoscopic confocal laser endomicroscopy in the assessment of mucosal barrier defects.

PubMed

Chang, Jeff; Ip, Matthew; Yang, Michael; Wong, Brendon; Power, Theresa; Lin, Lisa; Xuan, Wei; Phan, Tri Giang; Leong, Rupert W

2016-04-01

Confocal laser endomicroscopy can dynamically assess intestinal mucosal barrier defects and increased intestinal permeability (IP). These are functional features that do not have corresponding appearance on histopathology. As such, previous pathology training may not be beneficial in learning these dynamic features. This study aims to evaluate the diagnostic accuracy, learning curve, inter- and intraobserver agreement for identifying features of increased IP in experienced and inexperienced analysts and pathologists. A total of 180 endoscopic confocal laser endomicroscopy (Pentax EC-3870FK; Pentax, Tokyo, Japan) images of the terminal ileum, subdivided into 6 sets of 30 were evaluated by 6 experienced analysts, 13 inexperienced analysts, and 2 pathologists, after a 30-minute teaching session. Cell-junction enhancement, fluorescein leak, and cell dropout were used to represent increased IP and were either present or absent in each image. For each image, the diagnostic accuracy, confidence, and quality were assessed. Diagnostic accuracy was significantly higher for experienced analysts compared with inexperienced analysts from the first set (96.7% vs 83.1%, P < .001) to the third set (95% vs 89.7, P = .127). No differences in accuracy were noted between inexperienced analysts and pathologists. Confidence (odds ratio, 8.71; 95% confidence interval, 5.58-13.57) and good image quality (odds ratio, 1.58; 95% confidence interval, 1.22-2.03) were associated with improved interpretation. Interobserver agreement κ values were high and improved with experience (experienced analysts, 0.83; inexperienced analysts, 0.73; and pathologists, 0.62). Intraobserver agreement was >0.86 for experienced observers. Features representative of increased IP can be rapidly learned with high inter- and intraobserver agreement. Confidence and image quality were significant predictors of accurate interpretation. Previous pathology training did not have an effect on learning. Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Can CT and MR Shape and Textural Features Differentiate Benign Versus Malignant Pleural Lesions?

PubMed

Pena, Elena; Ojiaku, MacArinze; Inacio, Joao R; Gupta, Ashish; Macdonald, D Blair; Shabana, Wael; Seely, Jean M; Rybicki, Frank J; Dennie, Carole; Thornhill, Rebecca E

2017-10-01

The study aimed to identify a radiomic approach based on CT and or magnetic resonance (MR) features (shape and texture) that may help differentiate benign versus malignant pleural lesions, and to assess if the radiomic model may improve confidence and accuracy of radiologists with different subspecialty backgrounds. Twenty-nine patients with pleural lesions studied on both contrast-enhanced CT and MR imaging were reviewed retrospectively. Three texture and three shape features were extracted. Combinations of features were used to generate logistic regression models using histopathology as outcome. Two thoracic and two abdominal radiologists evaluated their degree of confidence in malignancy. Diagnostic accuracy of radiologists was determined using contingency tables. Cohen's kappa coefficient was used to assess inter-reader agreement. Using optimal threshold criteria, sensitivity, specificity, and accuracy of each feature and combination of features were obtained and compared to the accuracy and confidence of radiologists. The CT model that best discriminated malignant from benign lesions revealed an AUC CT  = 0.92 ± 0.05 (P < 0.0001). The most discriminative MR model showed an AUC MR  = 0.87 ± 0.09 (P < 0.0001). The CT model was compared to the diagnostic confidence of all radiologists and the model outperformed both abdominal radiologists (P < 0.002), whereas the top discriminative MR model outperformed one of the abdominal radiologists (P = 0.02). The most discriminative MR model was more accurate than one abdominal (P = 0.04) and one thoracic radiologist (P = 0.02). Quantitative textural and shape analysis may help distinguish malignant from benign lesions. A radiomics-based approach may increase diagnostic confidence of abdominal radiologists on CT and MR and may potentially improve radiologists' accuracy in the assessment of pleural lesions characterized by MR. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

FDG-PET improves accuracy in distinguishing frontotemporal dementia and Alzheimer's disease.

PubMed

Foster, Norman L; Heidebrink, Judith L; Clark, Christopher M; Jagust, William J; Arnold, Steven E; Barbas, Nancy R; DeCarli, Charles S; Turner, R Scott; Koeppe, Robert A; Higdon, Roger; Minoshima, Satoshi

2007-10-01

Distinguishing Alzheimer's disease (AD) and frontotemporal dementia (FTD) currently relies on a clinical history and examination, but positron emission tomography with [(18)F] fluorodeoxyglucose (FDG-PET) shows different patterns of hypometabolism in these disorders that might aid differential diagnosis. Six dementia experts with variable FDG-PET experience made independent, forced choice, diagnostic decisions in 45 patients with pathologically confirmed AD (n = 31) or FTD (n = 14) using five separate methods: (1) review of clinical summaries, (2) a diagnostic checklist alone, (3) summary and checklist, (4) transaxial FDG-PET scans and (5) FDG-PET stereotactic surface projection (SSP) metabolic and statistical maps. In addition, we evaluated the effect of the sequential review of a clinical summary followed by SSP. Visual interpretation of SSP images was superior to clinical assessment and had the best inter-rater reliability (mean kappa = 0.78) and diagnostic accuracy (89.6%). It also had the highest specificity (97.6%) and sensitivity (86%), and positive likelihood ratio for FTD (36.5). The addition of FDG-PET to clinical summaries increased diagnostic accuracy and confidence for both AD and FTD. It was particularly helpful when raters were uncertain in their clinical diagnosis. Visual interpretation of FDG-PET after brief training is more reliable and accurate in distinguishing FTD from AD than clinical methods alone. FDG-PET adds important information that appropriately increases diagnostic confidence, even among experienced dementia specialists.

Efficacy and Clinical Utility of a High-Attenuation Object Artifact Reduction Algorithm in Flat-Detector Image Reconstruction Compared With Standard Image Reconstruction.

PubMed

Naehle, Claas P; Hechelhammer, Lukas; Richter, Heiko; Ryffel, Fabian; Wildermuth, Simon; Weber, Johannes

To evaluate the effectiveness and clinical utility of a metal artifact reduction (MAR) image reconstruction algorithm for the reduction of high-attenuation object (HAO)-related image artifacts. Images were quantitatively evaluated for image noise (noiseSD and noiserange) and qualitatively for artifact severity, gray-white-matter delineation, and diagnostic confidence with conventional reconstruction and after applying a MAR algorithm. Metal artifact reduction reduces noiseSD and noiserange (median [interquartile range]) at the level of HAO in 1-cm distance compared with conventional reconstruction (noiseSD: 60.0 [71.4] vs 12.8 [16.1] and noiserange: 262.0 [236.8] vs 72.0 [28.3]; P < 0.0001). Artifact severity (reader 1 [mean ± SD]: 1.1 ± 0.6 vs 2.4 ± 0.5, reader 2: 0.8 ± 0.6 vs 2.0 ± 0.4) at level of HAO and diagnostic confidence (reader 1: 1.6 ± 0.7 vs 2.6 ± 0.5, reader 2: 1.0 ± 0.6 vs 2.3 ± 0.7) significantly improved with MAR (P < 0.0001). Metal artifact reduction did not affect gray-white-matter delineation. Metal artifact reduction effectively reduces image artifacts caused by HAO and significantly improves diagnostic confidence without worsening gray-white-matter delineation.

The effects of divided attention at study and reporting procedure on regulation and monitoring for episodic recall.

PubMed

Sauer, James; Hope, Lorraine

2016-09-01

Eyewitnesses regulate the level of detail (grain size) reported to balance competing demands for informativeness and accuracy. However, research to date has predominantly examined metacognitive monitoring for semantic memory tasks, and used relatively artificial phased reporting procedures. Further, although the established role of confidence in this regulation process may affect the confidence-accuracy relation for volunteered responses in predictable ways, previous investigations of the confidence-accuracy relation for eyewitness recall have largely overlooked the regulation of response granularity. Using a non-phased paradigm, Experiment 1 compared reporting and monitoring following optimal and sub-optimal (divided attention) encoding conditions. Participants showed evidence of sacrificing accuracy for informativeness, even when memory quality was relatively weak. Participants in the divided (cf. full) attention condition showed reduced accuracy for fine- but not coarse-grained responses. However, indices of discrimination and confidence diagnosticity showed no effect of divided attention. Experiment 2 compared the effects of divided attention at encoding on reporting and monitoring using both non-phased and 2-phase procedures. Divided attention effects were consistent with Experiment 1. However, compared to those in the non-phased condition, participants in the 2-phase condition displayed a more conservative control strategy, and confidence ratings were less diagnostic of accuracy. When memory quality was reduced, although attempts to balance informativeness and accuracy increased the chance of fine-grained response errors, confidence provided an index of the likely accuracy of volunteered fine-grained responses for both condition. Copyright © 2016 Elsevier B.V. All rights reserved.

Survey of the prevalence and methodology of quality assurance for B-mode ultrasound image quality among veterinary sonographers.

PubMed

Hoscheit, Larry P; Heng, Hock Gan; Lim, Chee Kin; Weng, Hsin-Yi

2018-05-01

Image quality in B-mode ultrasound is important as it reflects the diagnostic accuracy and diagnostic information provided during clinical scanning. Quality assurance programs for B-mode ultrasound systems/components are comprised of initial quality acceptance testing and subsequent regularly scheduled quality control testing. The importance of quality assurance programs for B-mode ultrasound image quality using ultrasound phantoms is well documented in the human medical and medical physics literature. The purpose of this prospective, cross-sectional, survey study was to determine the prevalence and methodology of quality acceptance testing and quality control testing of image quality for ultrasound system/components among veterinary sonographers. An online electronic survey was sent to 1497 members of veterinary imaging organizations: the American College of Veterinary Radiology, the Veterinary Ultrasound Society, and the European Association of Veterinary Diagnostic Imaging, and a total of 167 responses were received. The results showed that the percentages of veterinary sonographers performing quality acceptance testing and quality control testing are 42% (64/151; 95% confidence interval 34-52%) and 26% (40/156: 95% confidence interval 19-33%) respectively. Of the respondents who claimed to have quality acceptance testing or quality control testing of image quality in place for their ultrasound system/components, 0% have performed quality acceptance testing or quality control testing correctly (quality acceptance testing 95% confidence interval: 0-6%, quality control testing 95% confidence interval: 0-11%). Further education and guidelines are recommended for veterinary sonographers in the area of quality acceptance testing and quality control testing for B-mode ultrasound equipment/components. © 2018 American College of Veterinary Radiology.

Detection of crestal radiolucencies around dental implants: an in vitro experimental study.

PubMed

Sirin, Yigit; Horasan, Sinan; Yaman, Duygu; Basegmez, Cansu; Tanyel, Cem; Aral, Ali; Guven, Koray

2012-07-01

The aim of this study was to compare the diagnostic potentials and practical advantages of different imaging modalities in detecting bone defects around dental implants. Crestal bone defects with sequentially larger diameters were randomly prepared around 100 implants that were inserted in bovine bone blocks. Conventional periapical radiography (PR), direct digital radiography (DDR), panoramic radiography (PANO), cone-beam computed tomography (CBCT), and multislice computed tomography (MSCT) were performed for all specimens. The diagnostic accuracies of the devices, confidence of the answers, subjective image quality, defect visibility in planar orientations, and duration of diagnosis were analyzed based on the interpretations of 7 calibrated observers. The agreement levels of intra- and interobserver scores were rated good. PR, DDR, and CBCT were mostly more accurate than PANO and MSCT (P < .05). Confidence levels were positively correlated with the defect size (ρ = 0.20, P < .01), and that of DDR was the highest (P < .05). The subjective image quality of PR and DDR was higher than that of CBCT, PANO, and MSCT (P < .05 for all comparisons). Axial-coronal-sagittal visibilities of the defects were higher for CBCT compared with MSCT (P < .05). The diagnostic time was shorter for DDR (P < .05) and longer for the tomographic systems (P < .05) than for the other devices. DDR may provide a faster and more confident diagnostic option that is as accurate as PR in detecting peri-implant radiolucencies. CBCT has a comparable potential to these intraoral systems but with slower decision making and lower image quality, whereas PANO and MSCT become more reliable when bone defects have a diameter that is at least 1.5 mm larger than that of the implant. Copyright © 2012 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Arrhythmia discrimination by physician and defibrillator: importance of atrial channel.

PubMed

Diemberger, Igor; Martignani, Cristian; Biffi, Mauro; Frabetti, Lorenzo; Valzania, Cinzia; Cooke, Robin M T; Rapezzi, Claudio; Branzi, Angelo; Boriani, Giuseppe

2012-01-26

Many ICD carriers experience inappropriate shocks, but the relative merits of dual- /single-chamber devices for arrhythmia discrimination still remain unclear. We explored possible advantages of the atrial data provided by dual-chamber implantable defibrillators (ICD) for discrimination of real-life supraventricular/ventricular tachyarrhythmias (SVT/VT). 100 dual-chamber traces from 24 ICD were blindly reviewed in dual-chamber and simulated single-chamber (with/without discriminator data) reading modes by five electrophysiologists who determined chamber of origin and provided Likert-scale "confidence" ratings. We assessed 1) intra/interobserver concordance; 2) diagnostic accuracy, using expert diagnoses as a reference standard; 3) ROC curves of sensitivity/specificity of "likelihood perception" scores, generated by combining chamber-of-origin diagnostic judgments with Likert-scale "confidence" ratings. We also assessed diagnostic accuracy of automated discrimination by all possible dual-/single-chamber algorithm configurations. Interobserver concordance was "substantial" (modified Cohen kappa-test values for dual-/single-chamber, 0.79/0.68); intraobserver concordance "almost complete" (kappa ≥ 0.89). Dual-chamber mode provided best diagnostic sensitivity/specificity (99%/92%) and highest reader confidence (p<0.001). Area under ROC curves of sensitivity/specificity values for the "likelihood perception" score (representing electrophysiologists' perceptions of the likelihood that an episode was of ventricular origin) was highest in dual-chamber mode (0.98 vs. 0.93 for both single-chamber modes; p<0.001). Regarding automated discrimination, all four dual-chamber configurations conferred 100% sensitivity (specificity values ranged 39%-88%), whereas single-chamber configurations appeared inferior (best sensitivity/specificity combination, 89%/64%). Availability of the atrial channel helps in reducing inappropriate ICD therapies by providing relevant advantages in terms of both appropriate cardiologist's post-hoc discrimination of SVT/VT (improving program tailoring) and automated arrhythmia discrimination. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Real-time Raman spectroscopy for in vivo, online gastric cancer diagnosis during clinical endoscopic examination.

PubMed

Duraipandian, Shiyamala; Sylvest Bergholt, Mads; Zheng, Wei; Yu Ho, Khek; Teh, Ming; Guan Yeoh, Khay; Bok Yan So, Jimmy; Shabbir, Asim; Huang, Zhiwei

2012-08-01

Optical spectroscopic techniques including reflectance, fluorescence and Raman spectroscopy have shown promising potential for in vivo precancer and cancer diagnostics in a variety of organs. However, data-analysis has mostly been limited to post-processing and off-line algorithm development. In this work, we develop a fully automated on-line Raman spectral diagnostics framework integrated with a multimodal image-guided Raman technique for real-time in vivo cancer detection at endoscopy. A total of 2748 in vivo gastric tissue spectra (2465 normal and 283 cancer) were acquired from 305 patients recruited to construct a spectral database for diagnostic algorithms development. The novel diagnostic scheme developed implements on-line preprocessing, outlier detection based on principal component analysis statistics (i.e., Hotelling's T2 and Q-residuals) for tissue Raman spectra verification as well as for organ specific probabilistic diagnostics using different diagnostic algorithms. Free-running optical diagnosis and processing time of < 0.5 s can be achieved, which is critical to realizing real-time in vivo tissue diagnostics during clinical endoscopic examination. The optimized partial least squares-discriminant analysis (PLS-DA) models based on the randomly resampled training database (80% for learning and 20% for testing) provide the diagnostic accuracy of 85.6% [95% confidence interval (CI): 82.9% to 88.2%] [sensitivity of 80.5% (95% CI: 71.4% to 89.6%) and specificity of 86.2% (95% CI: 83.6% to 88.7%)] for the detection of gastric cancer. The PLS-DA algorithms are further applied prospectively on 10 gastric patients at gastroscopy, achieving the predictive accuracy of 80.0% (60/75) [sensitivity of 90.0% (27/30) and specificity of 73.3% (33/45)] for in vivo diagnosis of gastric cancer. The receiver operating characteristics curves further confirmed the efficacy of Raman endoscopy together with PLS-DA algorithms for in vivo prospective diagnosis of gastric cancer. This work successfully moves biomedical Raman spectroscopic technique into real-time, on-line clinical cancer diagnosis, especially in routine endoscopic diagnostic applications.

Real-time Raman spectroscopy for in vivo, online gastric cancer diagnosis during clinical endoscopic examination

NASA Astrophysics Data System (ADS)

Duraipandian, Shiyamala; Sylvest Bergholt, Mads; Zheng, Wei; Yu Ho, Khek; Teh, Ming; Guan Yeoh, Khay; Bok Yan So, Jimmy; Shabbir, Asim; Huang, Zhiwei

2012-08-01

Optical spectroscopic techniques including reflectance, fluorescence and Raman spectroscopy have shown promising potential for in vivo precancer and cancer diagnostics in a variety of organs. However, data-analysis has mostly been limited to post-processing and off-line algorithm development. In this work, we develop a fully automated on-line Raman spectral diagnostics framework integrated with a multimodal image-guided Raman technique for real-time in vivo cancer detection at endoscopy. A total of 2748 in vivo gastric tissue spectra (2465 normal and 283 cancer) were acquired from 305 patients recruited to construct a spectral database for diagnostic algorithms development. The novel diagnostic scheme developed implements on-line preprocessing, outlier detection based on principal component analysis statistics (i.e., Hotelling's T2 and Q-residuals) for tissue Raman spectra verification as well as for organ specific probabilistic diagnostics using different diagnostic algorithms. Free-running optical diagnosis and processing time of < 0.5 s can be achieved, which is critical to realizing real-time in vivo tissue diagnostics during clinical endoscopic examination. The optimized partial least squares-discriminant analysis (PLS-DA) models based on the randomly resampled training database (80% for learning and 20% for testing) provide the diagnostic accuracy of 85.6% [95% confidence interval (CI): 82.9% to 88.2%] [sensitivity of 80.5% (95% CI: 71.4% to 89.6%) and specificity of 86.2% (95% CI: 83.6% to 88.7%)] for the detection of gastric cancer. The PLS-DA algorithms are further applied prospectively on 10 gastric patients at gastroscopy, achieving the predictive accuracy of 80.0% (60/75) [sensitivity of 90.0% (27/30) and specificity of 73.3% (33/45)] for in vivo diagnosis of gastric cancer. The receiver operating characteristics curves further confirmed the efficacy of Raman endoscopy together with PLS-DA algorithms for in vivo prospective diagnosis of gastric cancer. This work successfully moves biomedical Raman spectroscopic technique into real-time, on-line clinical cancer diagnosis, especially in routine endoscopic diagnostic applications.

Multiparametric magnetic resonance imaging of the prostate: current concepts*

PubMed Central

Bittencourt, Leonardo Kayat; Hausmann, Daniel; Sabaneeff, Natalia; Gasparetto, Emerson Leandro; Barentsz, Jelle O.

2014-01-01

Multiparametric MR (mpMR) imaging is rapidly evolving into the mainstay in prostate cancer (PCa) imaging. Generally, the examination consists of T2-weighted sequences, diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) evaluation, and less often proton MR spectroscopy imaging (MRSI). Those functional techniques are related to biological properties of the tumor, so that DWI correlates to cellularity and Gleason scores, DCE correlates to angiogenesis, and MRSI correlates to cell membrane turnover. The combined use of those techniques enhances the diagnostic confidence and allows for better characterization of PCa. The present article reviews and illustrates the technical aspects and clinical applications of each component of mpMR imaging, in a practical approach from the urological standpoint. PMID:25741104

Ultrasound-guided core biopsy in the diagnosis of lymphoma of the head and neck. A 9 year experience

PubMed Central

Burke, C; Thomas, R; Inglis, C; Baldwin, A; Ramesar, K; Grace, R; Howlett, D C

2011-01-01

Objectives This retrospective study aimed to evaluate the diagnostic utility of ultrasound-guided core biopsy (USCB) in lymphoma of the head and neck, in particular whether core biopsy can provide sufficient diagnostic information for definitive treatment. Methods All lymphomas diagnosed in the head and neck at Eastbourne General Hospital between January 2000 and June 2009 were identified. Radiology and pathology reports were reviewed and the diagnostic techniques recorded. The type of biopsy (fine needle aspiration, needle core, surgical excision biopsy) used to establish a diagnosis sufficient to allow treatment, i.e. the "index" diagnostic technique, was identified. Previous inconclusive or inadequate biopsies were noted. Pathology reports based on USCB were graded 0–3 according to diagnostic completeness and ability to provide treatment information. Results Of 691 overall cases of lymphoma diagnosed over the 9 year period, 171 different patients presented with lymphoma in the head and neck. Of these 171, 83 had USCB biopsy during diagnostic work up. 60 were regarded as grade 3 where a confident diagnosis of lymphoma was made. In seven patients, clinical management proceeded on the basis of a suggestive (grade 2) pathology report without surgical excision, and these were therefore also included as "index" biopsies. Overall therefore, 67/83 core biopsies (81%) provided adequate information to allow treatment. Surgical excision biopsy was the index modality in 104 cases. Conclusion In the majority of cases USCB is adequate for confident histopathological diagnosis avoiding the need for surgical excision biopsy in cases of suspected head and neck lymphoma. PMID:21427181

A proposal of the diagnosis-dynamic characteristic (DDC) model describing the relation between search time and confidence levels for a dichotomous judgment, and its application to ROC curve generation

NASA Astrophysics Data System (ADS)

Matsumoto, Toru; Fukuda, Nobuo; Furukawa, Akira; Suwa, Koji; Wada, Shinichi; Matsumoto, Mitsuomi; Sone, Shusuke

2006-03-01

When physicians inspect an image, they make up a certain degree of confidence that the image are abnormal; p(t), or normal; n(t)[n(t)=1-p(t)]. After infinite time of the inspection, they reach the equilibrium levels of the confidence of p*=p(∞) and n*=n(∞). There are psychological conflicts between the decisions of normal and abnormal. We assume that the decision of "normal" is distracted by the decision of "abnormal" by a factor of k(1 + ap), and in an inverse direction by a factor of k(1 + bn), where k ( > 0) is a parameter that relates with image quality and skill of the physicians, and a and b are unknown constants. After the infinite time of inspection, the conflict reaches the equilibrium, which satisfies the equation, k(1 + ap*)n* = k(1 + bn*)p*. Here we define a parameter C, which is 2p*/[p*(1 - p*)]. After the infinite time of inspection, the conflict reaches the equilibrium, which satisfies t that changes in the confidence level with the time (dp/dt) is proportional to [k(1+ap)n - k(1+bn)p], i.e. k[-cp2 + (c - 2)p + 1]. Solving the differential equation, we derived the equation; t(p) and p(t) depending with the parameters; k, c, S. S (0-1) is the value arbitrary selected and related with probability of "abnormal" before the image inspection (S = p(0)). Image reading studies were executed for CT images. ROC curves were generated both by the traditional 4-step score-based method and by the confidence level; p estimated from the equation t(p) of the DDC model using observed judgment time. It was concluded that ROC curves could be generated by measuring time for dichotomous judgment without the subjective scores of diagnostic confidence and applying the DDC model.

Can We Confidently Diagnose Pilomatricoma with Fine Needle Aspiration Cytology?

PubMed Central

WONG, Yin-Ping; MASIR, Noraidah; SHARIFAH, Noor Akmal

2015-01-01

Pilomatricomas can be confidently diagnosed cytologically due to their characteristic cytomorphological features. However, these lesions are rarely encountered by cytopathologists and thus pose a diagnostic dilemma to even experienced individuals, especially when the lesions are focally sampled. We describe two cases of histologically confirmed pilomatricoma. The first case is of a 13-year-old boy with posterior cervical ‘lymphadenopathy’, and the second one is of a 12-year-old girl with a lower cheek swelling. Both aspirates comprised predominantly atypical basal-like cells, with prominent nucleoli. ‘Ghost cells’ were readily identified by cell block in case two, but cell block in case one yielded no diagnostic material. In case two, pilomatricoma was accurately diagnosed pre-operatively. A cytological suspicion of a neoplastic process was raised in case one. Despite being diagnostically challenging, pilomatricoma can be diagnosed with careful observation of two unique cytological features of the lesions: (1) pathognomonic ‘ghost cells’ and (2) irregular, saw-toothed, loosely cohesive basaloid cells, with prominent nucleoli. The role of thorough sampling of the lesion, with multiple passes of various sites, cannot be overemphasized. PMID:25892955

Health information exchange reduces repeated diagnostic imaging for back pain.

PubMed

Bailey, James E; Pope, Rebecca A; Elliott, Elizabeth C; Wan, Jim Y; Waters, Teresa M; Frisse, Mark E

2013-07-01

This study seeks to determine whether health information exchange reduces repeated diagnostic imaging and related costs in emergency back pain evaluation. This was a longitudinal data analysis of health information exchange patient-visit data. All repeated emergency department (ED) patient visits for back pain with previous ED diagnostic imaging to a Memphis metropolitan area ED between August 1, 2007, and July 31, 2009, were included. Use of a regional health information exchange by ED personnel to access the patient's record during the emergency visit was the primary independent variable. Main outcomes included repeated lumbar or thoracic diagnostic imaging (radiograph, computed tomography [CT], or magnetic resonance imaging [MRI]) and total patient-visit estimated cost. One hundred seventy-nine (22.4%) of the 800 qualifying repeated back pain visits resulted in repeated diagnostic imaging (radiograph 84.9%, CT 6.1%, and MRI 9.5%). Health information exchange use in the study population was low, at 12.5%, and health care providers as opposed to administrative/nursing staff accounted for 80% of the total health information exchange use. Health information exchange use by any ED personnel was associated with reduced repeated diagnostic imaging (odds ratio 0.36; 95% confidence interval 0.18 to 0.71), as was physician or nurse practitioner health information exchange use (odds ratio 0.47; 95% confidence interval 0.23 to 0.96). No cost savings were associated with health information exchange use because of increased CT imaging when health care providers used health information exchange. Health information exchange use is associated with 64% lower odds of repeated diagnostic imaging in the emergency evaluation of back pain. Health information exchange effect on estimated costs was negligible. More studies are needed to evaluate specific strategies to increase health information exchange use and further decrease potentially unnecessary diagnostic imaging and associated costs of care. Copyright © 2013 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

Comparison of Diagnostic Accuracy of Radiation Dose-Equivalent Radiography, Multidetector Computed Tomography and Cone Beam Computed Tomography for Fractures of Adult Cadaveric Wrists

PubMed Central

Neubauer, Jakob; Benndorf, Matthias; Reidelbach, Carolin; Krauß, Tobias; Lampert, Florian; Zajonc, Horst; Kotter, Elmar; Langer, Mathias; Fiebich, Martin; Goerke, Sebastian M.

2016-01-01

Purpose To compare the diagnostic accuracy of radiography, to radiography equivalent dose multidetector computed tomography (RED-MDCT) and to radiography equivalent dose cone beam computed tomography (RED-CBCT) for wrist fractures. Methods As study subjects we obtained 10 cadaveric human hands from body donors. Distal radius, distal ulna and carpal bones (n = 100) were artificially fractured in random order in a controlled experimental setting. We performed radiation dose equivalent radiography (settings as in standard clinical care), RED-MDCT in a 320 row MDCT with single shot mode and RED-CBCT in a device dedicated to musculoskeletal imaging. Three raters independently evaluated the resulting images for fractures and the level of confidence for each finding. Gold standard was evaluated by consensus reading of a high-dose MDCT. Results Pooled sensitivity was higher in RED-MDCT with 0.89 and RED-MDCT with 0.81 compared to radiography with 0.54 (P = < .004). No significant differences were detected concerning the modalities’ specificities (with values between P = .98). Raters' confidence was higher in RED-MDCT and RED-CBCT compared to radiography (P < .001). Conclusion The diagnostic accuracy of RED-MDCT and RED-CBCT for wrist fractures proved to be similar and in some parts even higher compared to radiography. Readers are more confident in their reporting with the cross sectional modalities. Dose equivalent cross sectional computed tomography of the wrist could replace plain radiography for fracture diagnosis in the long run. PMID:27788215

A Meta-Analysis of the Diagnostic Accuracy of Circular RNAs in Digestive System Malignancy.

PubMed

Chen, Zhiqiang; Zhang, Long; Han, Guoyong; Zuo, Xueliang; Zhang, Yao; Zhu, Qin; Wu, Jindao; Wang, Xuehao

2018-01-01

Circular RNAs (circRNAs), a novel class of noncoding RNAs, have been found to be dysregulated in various cancers. However, the clinical application value of these circRNAs in digestive system cancers remains to be clarified. We aimed to comprehensively explore the potential role of circRNAs as diagnostic indicators in digestive system malignancies. Relevant studies were systematically retrieved from PubMed, Web of Science and the Cochrane Library. The data that were required to complete 2 × 2 contingency tables were obtained from the included studies. Stratified analyses by cancer type, sample size and publication year were performed. Thirteen studies with 2,276 individuals were included in the meta-analysis. The pooled sensitivity and specificity of circRNAs in the diagnosis of digestive system malignancy were 0.72 [95% confidence interval (CI): 0.65-0.77] and 0.77 (95% CI: 0.72-0.81), respectively. The overall positive likelihood ratio was 3.09 (95% CI: 2.64-3.62), and the overall negative likelihood ratio was 0.37 (95% CI: 0.31-0.44). The pooled diagnostic odds ratio was 8.38 (95% CI: 6.86-10.25), and the overall area under the curve was 0.81 (95% CI: 0.77-0.84), indicating good discriminative ability of circRNAs as biomarkers for digestive system malignancy. circRNAs distinguish patients with digestive system cancer from controls with relatively high diagnostic accuracy. circRNAs may be used as potential biomarkers for the diagnosis of digestive system malignancy. © 2018 The Author(s). Published by S. Karger AG, Basel.

Accuracy of dementia diagnosis: a direct comparison between radiologists and a computerized method.

PubMed

Klöppel, Stefan; Stonnington, Cynthia M; Barnes, Josephine; Chen, Frederick; Chu, Carlton; Good, Catriona D; Mader, Irina; Mitchell, L Anne; Patel, Ameet C; Roberts, Catherine C; Fox, Nick C; Jack, Clifford R; Ashburner, John; Frackowiak, Richard S J

2008-11-01

There has been recent interest in the application of machine learning techniques to neuroimaging-based diagnosis. These methods promise fully automated, standard PC-based clinical decisions, unbiased by variable radiological expertise. We recently used support vector machines (SVMs) to separate sporadic Alzheimer's disease from normal ageing and from fronto-temporal lobar degeneration (FTLD). In this study, we compare the results to those obtained by radiologists. A binary diagnostic classification was made by six radiologists with different levels of experience on the same scans and information that had been previously analysed with SVM. SVMs correctly classified 95% (sensitivity/specificity: 95/95) of sporadic Alzheimer's disease and controls into their respective groups. Radiologists correctly classified 65-95% (median 89%; sensitivity/specificity: 88/90) of scans. SVM correctly classified another set of sporadic Alzheimer's disease in 93% (sensitivity/specificity: 100/86) of cases, whereas radiologists ranged between 80% and 90% (median 83%; sensitivity/specificity: 80/85). SVMs were better at separating patients with sporadic Alzheimer's disease from those with FTLD (SVM 89%; sensitivity/specificity: 83/95; compared to radiological range from 63% to 83%; median 71%; sensitivity/specificity: 64/76). Radiologists were always accurate when they reported a high degree of diagnostic confidence. The results show that well-trained neuroradiologists classify typical Alzheimer's disease-associated scans comparable to SVMs. However, SVMs require no expert knowledge and trained SVMs can readily be exchanged between centres for use in diagnostic classification. These results are encouraging and indicate a role for computerized diagnostic methods in clinical practice.

Accuracy of dementia diagnosis—a direct comparison between radiologists and a computerized method

PubMed Central

Stonnington, Cynthia M.; Barnes, Josephine; Chen, Frederick; Chu, Carlton; Good, Catriona D.; Mader, Irina; Mitchell, L. Anne; Patel, Ameet C.; Roberts, Catherine C.; Fox, Nick C.; Jack, Clifford R.; Ashburner, John; Frackowiak, Richard S. J.

2008-01-01

There has been recent interest in the application of machine learning techniques to neuroimaging-based diagnosis. These methods promise fully automated, standard PC-based clinical decisions, unbiased by variable radiological expertise. We recently used support vector machines (SVMs) to separate sporadic Alzheimer's disease from normal ageing and from fronto-temporal lobar degeneration (FTLD). In this study, we compare the results to those obtained by radiologists. A binary diagnostic classification was made by six radiologists with different levels of experience on the same scans and information that had been previously analysed with SVM. SVMs correctly classified 95% (sensitivity/specificity: 95/95) of sporadic Alzheimer's disease and controls into their respective groups. Radiologists correctly classified 65–95% (median 89%; sensitivity/specificity: 88/90) of scans. SVM correctly classified another set of sporadic Alzheimer's disease in 93% (sensitivity/specificity: 100/86) of cases, whereas radiologists ranged between 80% and 90% (median 83%; sensitivity/specificity: 80/85). SVMs were better at separating patients with sporadic Alzheimer's disease from those with FTLD (SVM 89%; sensitivity/specificity: 83/95; compared to radiological range from 63% to 83%; median 71%; sensitivity/specificity: 64/76). Radiologists were always accurate when they reported a high degree of diagnostic confidence. The results show that well-trained neuroradiologists classify typical Alzheimer's disease-associated scans comparable to SVMs. However, SVMs require no expert knowledge and trained SVMs can readily be exchanged between centres for use in diagnostic classification. These results are encouraging and indicate a role for computerized diagnostic methods in clinical practice. PMID:18835868

Clinical diagnosis of partial or complete anterior cruciate ligament tears using patients' history elements and physical examination tests.

PubMed

Décary, Simon; Fallaha, Michel; Belzile, Sylvain; Martel-Pelletier, Johanne; Pelletier, Jean-Pierre; Feldman, Debbie; Sylvestre, Marie-Pierre; Vendittoli, Pascal-André; Desmeules, François

2018-01-01

To assess the diagnostic validity of clusters combining history elements and physical examination tests to diagnose partial or complete anterior cruciate ligament (ACL) tears. Prospective diagnostic study. Orthopaedic clinics (n = 2), family medicine clinics (n = 2) and community-dwelling. Consecutive patients with a knee complaint (n = 279) and consulting one of the participating orthopaedic surgeons (n = 3) or sport medicine physicians (n = 2). Not applicable. History elements and physical examination tests performed independently were compared to the reference standard: an expert physicians' composite diagnosis including history elements, physical tests and confirmatory magnetic resonance imaging. Penalized logistic regression (LASSO) was used to identify history elements and physical examination tests associated with the diagnosis of ACL tear and recursive partitioning was used to develop diagnostic clusters. Diagnostic accuracy measures including sensitivity (Se), specificity (Sp), predictive values and positive and negative likelihood ratios (LR+/-) with associated 95% confidence intervals (CI) were calculated. Forty-three individuals received a diagnosis of partial or complete ACL tear (15.4% of total cohort). The Lachman test alone was able to diagnose partial or complete ACL tears (LR+: 38.4; 95%CI: 16.0-92.5). Combining a history of trauma during a pivot with a "popping" sensation also reached a high diagnostic validity for partial or complete tears (LR+: 9.8; 95%CI: 5.6-17.3). Combining a history of trauma during a pivot, immediate effusion after trauma and a positive Lachman test was able to identify individuals with a complete ACL tear (LR+: 17.5; 95%CI: 9.8-31.5). Finally, combining a negative history of pivot or a negative popping sensation during trauma with a negative Lachman or pivot shift test was able to exclude both partial or complete ACL tears (LR-: 0.08; 95%CI: 0.03-0.24). Diagnostic clusters combining history elements and physical examination tests can support the differential diagnosis of ACL tears compared to various knee disorders.

Validity of Combining History Elements and Physical Examination Tests to Diagnose Patellofemoral Pain.

PubMed

Décary, Simon; Frémont, Pierre; Pelletier, Bruno; Fallaha, Michel; Belzile, Sylvain; Martel-Pelletier, Johanne; Pelletier, Jean-Pierre; Feldman, Debbie; Sylvestre, Marie-Pierre; Vendittoli, Pascal-André; Desmeules, François

2018-04-01

To assess the validity of diagnostic clusters combining history elements and physical examination tests to diagnose or exclude patellofemoral pain (PFP). Prospective diagnostic study. Orthopedic outpatient clinics, family medicine clinics, and community-dwelling. Consecutive patients (N=279) consulting one of the participating orthopedic surgeons (n=3) or sport medicine physicians (n=2) for any knee complaint. Not applicable. History elements and physical examination tests were obtained by a trained physiotherapist blinded to the reference standard: a composite diagnosis including both physical examination tests and imaging results interpretation performed by an expert physician. Penalized logistic regression (least absolute shrinkage and selection operator) was used to identify history elements and physical examination tests associated with the diagnosis of PFP, and recursive partitioning was used to develop diagnostic clusters. Diagnostic accuracy measures including sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios with associated 95% confidence intervals (CIs) were calculated. Two hundred seventy-nine participants were evaluated, and 75 had a diagnosis of PFP (26.9%). Different combinations of history elements and physical examination tests including the age of participants, knee pain location, difficulty descending stairs, patellar facet palpation, and passive knee extension range of motion were associated with a diagnosis of PFP and used in clusters to accurately discriminate between individuals with PFP and individuals without PFP. Two diagnostic clusters developed to confirm the presence of PFP yielded a positive likelihood ratio of 8.7 (95% CI, 5.2-14.6) and 3 clusters to exclude PFP yielded a negative likelihood ratio of .12 (95% CI, .06-.27). Diagnostic clusters combining common history elements and physical examination tests that can accurately diagnose or exclude PFP compared to various knee disorders were developed. External validation is required before clinical use. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Cost-effectiveness of using a molecular diagnostic test to improve preoperative diagnosis of thyroid cancer.

PubMed

Najafzadeh, Mehdi; Marra, Carlo A; Lynd, Larry D; Wiseman, Sam M

2012-12-01

Fine-needle aspiration biopsy (FNAB) is a safe and inexpensive diagnostic procedure for evaluating thyroid nodules.Up to 25% of the results from an FNAB, however, may not be diagnostic or may be indeterminate, leading to a subsequent diagnostic thyroid surgery. A new molecularly based diagnostic test could potentially reduce indeterminate cytological results and, with high accuracy, provide a definitive diagnosis for cancer in thyroid nodules. The aim of the study was to estimate the cost-effectiveness of utilizing a molecular diagnostic (DX) test as an adjunct to FNAB, compared with NoDX, to improve the preoperative diagnosis of thyroid nodules. We constructed a patient-level simulation model to estimate the clinical and economic outcomes of using a DX test compared with current practice (NoDX) for the diagnosis of thyroid nodules. By using a cost-effectiveness framework, we measured incremental clinical benefits in terms of quality-adjusted life-years and incremental costs over a 10-year time horizon. Assuming 95% sensitivity and specificity of the Dx test when used as an adjunct to FNAB, the utilization of the DX test resulted in a gain of 0.046 quality-adjusted life-years (95% confidence interval 0.019-0.078) and a saving of $1087 (95% confidence interval $691-$1533) in direct costs per patient. If the cost of the Dx test is less than $1087 per test, we expect to save quality-adjusted life-years and reduce costs when it is utilized. Sensitivity of the DX test, compared with specificity, had a larger influence on the overall outcomes. Copyright © 2012 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Participants' barriers to diagnostic resolution and factors associated with needing patient navigation.

PubMed

Krok-Schoen, Jessica L; Brewer, Brittany M; Young, Gregory S; Weier, Rory C; Tatum, Cathy M; DeGraffinreid, Cecilia R; Paskett, Electra D

2015-08-15

Patient navigation (PN) may improve cancer care by identifying and removing patient-reported barriers to care. In 2012, the American College of Surgeons Commission on Cancer (CoC) announced that health care facilities seeking CoC accreditation must have PN processes in place by January 1, 2015. Given these unfunded mandates, hospitals are looking for cost-effective ways to implement PN. This study examined demographic and psychosocial predictors of barriers to diagnostic resolution among individuals with a cancer screening abnormality enrolled in the Ohio Patient Navigation Research Project. Data were obtained from patients who received care at 1 of 9 Ohio Patient Navigation Research Project intervention clinics. Descriptive statistics and logistic regression models were used. There were 424 participants, and 151 (35.6%) reported a barrier to diagnostic resolution within 90 days of study consent. The most commonly reported barriers were misconceptions about a test or treatment (16.4%), difficulty in communicating with the provider (15.0%), and scheduling problems (11.5%). Univariate analyses indicated that race, education, employment, income, insurance, clinic type, friend support, and physical and psychological functioning were significantly associated with reporting a barrier to diagnostic resolution. Multivariate analyses found that comorbidities (odds ratio, 1.65; 95% confidence interval, 1.04-2.61) and higher intrusive thoughts and feelings (odds ratio, 1.25; 95% confidence interval, 1.10-1.41) were significantly associated with reporting a barrier to diagnostic resolution. The results suggest that demographic and psychosocial factors are associated with barriers to diagnostic resolution. To ensure compliance with the CoC mandate and provide timely care to all patients, CoC-accredited facilities can systematically identify the patients most likely to have barriers to care and assign them to PN. © 2015 American Cancer Society.

Correcting AUC for Measurement Error.

PubMed

Rosner, Bernard; Tworoger, Shelley; Qiu, Weiliang

2015-12-01

Diagnostic biomarkers are used frequently in epidemiologic and clinical work. The ability of a diagnostic biomarker to discriminate between subjects who develop disease (cases) and subjects who do not (controls) is often measured by the area under the receiver operating characteristic curve (AUC). The diagnostic biomarkers are usually measured with error. Ignoring measurement error can cause biased estimation of AUC, which results in misleading interpretation of the efficacy of a diagnostic biomarker. Several methods have been proposed to correct AUC for measurement error, most of which required the normality assumption for the distributions of diagnostic biomarkers. In this article, we propose a new method to correct AUC for measurement error and derive approximate confidence limits for the corrected AUC. The proposed method does not require the normality assumption. Both real data analyses and simulation studies show good performance of the proposed measurement error correction method.

Application of statistical process control to qualitative molecular diagnostic assays.

PubMed

O'Brien, Cathal P; Finn, Stephen P

2014-01-01

Modern pathology laboratories and in particular high throughput laboratories such as clinical chemistry have developed a reliable system for statistical process control (SPC). Such a system is absent from the majority of molecular laboratories and where present is confined to quantitative assays. As the inability to apply SPC to an assay is an obvious disadvantage this study aimed to solve this problem by using a frequency estimate coupled with a confidence interval calculation to detect deviations from an expected mutation frequency. The results of this study demonstrate the strengths and weaknesses of this approach and highlight minimum sample number requirements. Notably, assays with low mutation frequencies and detection of small deviations from an expected value require greater sample numbers to mitigate a protracted time to detection. Modeled laboratory data was also used to highlight how this approach might be applied in a routine molecular laboratory. This article is the first to describe the application of SPC to qualitative laboratory data.

The role of latex agglutination test for the etiological diagnosis of pleural effusion in children and adolescents.

PubMed

Camargos, Paulo; Fonseca, Ana Cristina; Amantéa, Sérgio; Oliveira, Elizabeth; Benfica, Maria das Graças; Chamone, Chequer

2017-05-01

The etiological diagnosis of pleural effusion is a difficult task because the diagnostic tools can only establish a definitive etiological diagnosis in at most 76% of cases. To verify the diagnostic accuracy of the latex agglutination test (LAT) for the etiological diagnosis of pleural effusions caused by Streptococcus pneumoniae and Haemophilus influenzae type b. After thoracocentesis, paired fresh samples of pleural fluid from 418 children and adolescents were included in this investigation. They were tested blindly and simultaneously through counterimmunoelectrophoresis (CIE) and LAT for both bacteria. Sensitivity, specificity, predictive values and likelihood ratios (LR) were calculated taking CIE as a reference standard. The sensitivity and specificity of LAT was 100% (95% confidence interval, 94.4%-100%) and 83.3% (95% confidence interval, 79.0%-87.0%), respectively, whereas the positive (calculated from Bayes' theorem) and negative predictive values were, respectively, lower than 1% and 100% (95% confidence interval, 98.8%-100%). Positive and negative LR were 6.0 (95% confidence interval, 4.7-7.6) and zero, respectively. Our results suggest that LAT is a useful tool for the etiological diagnosis of pleural effusion. It is a reliable, rapid, simple to perform and shows an excellent yield in our studied population, helping to prescribe appropriate antibiotics for this clinical condition. © 2015 John Wiley & Sons Ltd.

Diagnostic accuracy of sequential co-registered PET+MR in comparison to PET/CT in local thoracic staging of malignant pleural mesothelioma.

PubMed

Martini, Katharina; Meier, Andreas; Opitz, Isabelle; Weder, Walter; Veit-Haibach, Patrick; Stahel, Rolf A; Frauenfelder, Thomas

2016-04-01

To investigate the diagnostic accuracy of sequential co-registered PET+MR (PET+MR) for local staging of malignant pleural mesothelioma (MPM) compared to PET/CT. In a prospective clinical trial 34 consecutive patients (median age 66 years; range 40-79 years; 1 female, 33 male) with known MPM, who underwent PET/CT and PET+MR exams for either staging or re-staging/follow-up were evaluated. Imaging was conducted using a tri-modality PET/CT-MR set-up (Discovery PET/CT 690, 3T Discovery MR 750w, both GE Healthcare, Waukesha, WI, USA). In 26 cases histopathology served as standard of reference. Two independent readers evaluated images for T and N stage, confidence level (sure to unsure; 1-3) and subjective overall image quality (very good to non-diagnostic; 1-4). Inter-observer agreement of T and N stages (Cohen's kappa) and interclass correlation coefficient (ICC) between PET/CT vs. PET+MR was calculated. Inter observer agreement for evaluation of T and N Stage in PET/CT images was excellent (k=0.844 and k=0.824, respectively), whereas PET+MR imaging showed substantial agreement in T and N stage (k=0.729 and k=0.691, respectively). The ICC of PET/CT vs. PET+MR for evaluation of both, T and N Stage, was excellent (ICC=0.951 and ICC=0.93, respectively). Diagnostic confidence was scored significantly higher in PET+MR compared to PET/CT (mean score=1.66 and 1.93, respectively; p=0.004). Image quality was diagnostic for all image series. Comparing pT and pN stage vs cT and cN stage (n=26 cases), both imaging modalities showed excellent agreement for T stage (ICCPET+MR=0.888 vs. ICCPET/CT=0.853, respectively) and substantial to moderate agreement for N stage (ICCPET+MR=0.683 vs. ICC=0.595PET/CT, respectively). Our findings suggest that diagnostic accuracy of PET+MR is comparable to PET/CT for local staging of MPM, whereas radiologists felt significantly more confident staging PET+MR compared to PET/CT images (p=0003), using dedicated sequences. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Accuracy of clinical neurological examination in diagnosing lumbo-sacral radiculopathy: a systematic literature review.

PubMed

Tawa, Nassib; Rhoda, Anthea; Diener, Ina

2017-02-23

Lumbar radiculopathy remains a clinical challenge among primary care clinicians in both assessment and diagnosis. This often leads to misdiagnosis and inappropriate treatment of patients resulting in poor health outcomes, exacerbating this already debilitating condition. This review evaluated 12 primary diagnostic accuracy studies that specifically assessed the performance of various individual and grouped clinical neurological tests in detecting nerve root impingement, as established in the current literature. Eight electronic data bases were searched for relevant articles from inception until July 2016. All primary diagnostic studies which investigated the accuracy of clinical neurological test (s) in diagnosing lumbar radiculopathy among patients with low back and referred leg symptoms were screened for inclusion. Qualifying studies were retrieved and independently assessed for methodological quality using the 'Quality Assessment of Diagnostic tests Accuracy Studies' criteria. A total of 12 studies which investigated standard components of clinical neurological examination of (sensory, motor, tendon reflex and neuro-dynamics) of the lumbo-sacral spine were included. The mean inter-observer agreement on quality assessment by two independent reviewers was fair (k = 0.3 - 0.7). The diagnostic performance of sensory testing using MR imaging as a reference standard demonstrated a sensitivity (confidence interval 95%) 0.61 (0.47-0.73) and a specificity of 0.63 (0.38-0.84). Motor tests sensitivity was poor to moderate, ranging from 0.13 (0.04-0.31) to 0.61 (0.36-0.83). Generally, the diagnostic performance of reflex testing was notably good with specificity ranging from (confidence interval 95%) 0.60 (0.51-0.69) to 0.93 (0.87-0.97) and sensitivity ranging from 0.14 (0.09-0.21) to 0.67 (0.21-0.94). Femoral nerve stretch test had a high sensitivity of (confidence interval 95%) 1.00 (0.40-1.00) and specificity of 0.83 (0.52-0.98) while SLR test recorded a mean sensitivity of 0.84 (0.72-0.92) and specificity of 0.78 (0.67-0.87). There is a scarcity of studies on the diagnostic accuracy of clinical neurological examination testing. Furthermore there seem to be a disconnect among researchers regarding the diagnostic utility of lower limb neuro-dynamic tests which include the Straight Leg Raise and Femoral Nerve tests for sciatic and femoral nerve respectively. Whether these tests are able to detect the presence of disc herniation and subsequent nerve root compression or hyper-sensitivity of the sacral and femoral plexus due to mechanical irritation still remains debatable.

The development and validation of a three-tier diagnostic test measuring pre-service elementary education and secondary science teachers' understanding of the water cycle

NASA Astrophysics Data System (ADS)

Schaffer, Dannah Lynn

The main goal of this research study was to develop and validate a three-tier diagnostic test to determine pre-service teachers' (PSTs) conceptual knowledge of the water cycle. For a three-tier diagnostic test, the first tier assesses content knowledge; in the second tier, a reason is selected for the content answer; and the third tier allows test-takers to select how confident they are in their answers for the first two tiers. The second goal of this study was to diagnose any alternative conceptions PSTs might have about the water cycle. The Water Cycle Diagnostic Test (WCDT) was developed using the theoretical framework by Treagust (1986, 1988, and 1995), and in similar studies that developed diagnostic tests (e.g., Calean & Subramaniam, 2010a; Odom & Barrow, 2007; Pesman & Eryilmaz, 2010). The final instrument consisted of 15 items along with a demographic survey that examined PSTs' weather-related experiences that may or may not have affected the PSTs' understanding of the water cycle. The WCDT was administered to 77 PSTs enrolled in science methods courses during the fall of 2012. Among the 77 participants, 37 of the PSTs were enrolled in elementary education (EPST) and 40 in secondary science (SPST). Using exploratory factor analysis, five categories were factored out for the WCDT: Phase Change of Water; Condensation and Storage; Clouds; Global Climate Change; and Movement through the Water Cycle. Analysis of the PSTs' responses demonstrated acceptable reliability (alpha = 0.62) for the instrument, and acceptable difficulty indices and discrimination indices for 12 of the items. Analysis indicated that the majority of the PSTs had a limited understanding of the water cycle. Of the PSTs sampled, SPSTs were significantly more confident in their answers' on the WCDT than the EPSTs. Completion of an undergraduate atmospheric science and/or meteorology course, as well as a higher interest in listening and/or viewing weather-related programs, resulted in PSTs having greater understanding and confidence in their answers on the WCDT. The analysis of the PSTs' responses revealed 49 potential alternative conceptions and areas where PSTs' lack of knowledge was revealed from the WCDT.

Improved image quality and diagnostic potential using ultra-high-resolution computed tomography of the lung with small scan FOV: A prospective study

PubMed Central

Wang, Yali; Hamal, Preeti; You, Xiaofang; Mao, Haixia; Li, Fei; Sun, Xiwen

2017-01-01

The aim of this study was to assess whether CT imaging using an ultra-high-resolution CT (UHRCT) scan with a small scan field of view (FOV) provides higher image quality and helps to reduce the follow-up period compared with a conventional high-resolution CT (CHRCT) scan. We identified patients with at least one pulmonary nodule at our hospital from July 2015 to November 2015. CHRCT and UHRCT scans were conducted in all enrolled patients. Three experienced radiologists evaluated the image quality using a 5-point score and made diagnoses. The paired images were displayed side by side in a random manner and annotations of scan information were removed. The following parameters including image quality, diagnostic confidence of radiologists, follow-up recommendations and diagnostic accuracy were assessed. A total of 52 patients (62 nodules) were included in this study. UHRCT scan provides a better image quality regarding the margin of nodules and solid internal component compared to that of CHRCT (P < 0.05). Readers have higher diagnostic confidence based on the UHRCT images than of CHRCT images (P<0.05). The follow-up recommendations were significantly different between UHRCT and CHRCT images (P<0.05). Compared with the surgical pathological findings, UHRCT had a relative higher diagnostic accuracy than CHRCT (P > 0.05). These findings suggest that the UHRCT prototype scanner provides a better image quality of subsolid nodules compared to CHRCT and contributes significantly to reduce the patients' follow-up period. PMID:28231320

Impact of time-resolved MRA on diagnostic accuracy in patients with symptomatic peripheral artery disease of the calf station.

PubMed

Hansmann, Jan; Michaely, Henrik J; Morelli, John N; Diehl, Steffen J; Meyer, Mathias; Schoenberg, Stefan O; Attenberger, Ulrike I

2013-12-01

The purpose of this article is to evaluate the added diagnostic accuracy of time-resolved MR angiography (MRA) of the calves compared with continuous-table-movement MRA in patients with symptomatic lower extremity peripheral artery disease (PAD) using digital subtraction angiography (DSA) correlation. Eighty-four consecutive patients with symptomatic PAD underwent a low-dose 3-T MRA protocol, consisting of continuous-table-movement MRA, acquired from the diaphragm to the calves, and an additional time-resolved MRA of the calves; 0.1 mmol/kg body weight (bw) of contrast material was used (0.07 mmol/kg bw for continuous-table-movement MRA and 0.03 mmol/kg bw for time-resolved MRA). Two radiologists rated image quality on a 4-point scale and stenosis degree on a 3-point scale. An additional assessment determined the degree of venous contamination and whether time-resolved MRA improved diagnostic confidence. The accuracy of stenosis gradation with continuous-table-movement and time-resolved MRA was compared with that of DSA as a correlation. Overall diagnostic accuracy was calculated for continuous-table-movement and time-resolved MRA. Median image quality was rated as good for 578 vessel segments with continuous-table-movement MRA and as excellent for 565 vessel segments with time-resolved MRA. Interreader agreement was excellent (κ = 0.80-0.84). Venous contamination interfered with diagnosis in more than 60% of continuous-table-movement MRA examinations. The degree of stenosis was assessed for 340 vessel segments. The diagnostic accuracies (continuous-table-movement MRA/time-resolved MRA) combined for the readers were obtained for the tibioperoneal trunk (84%/93%), anterior tibial (69%/87%), posterior tibial (85%/91%), and peroneal (67%/81%) arteries. The addition of time-resolved MRA improved diagnostic confidence in 69% of examinations. The addition of time-resolved MRA at the calf station improves diagnostic accuracy over continuous-table-movement MRA alone in symptomatic patients with PAD.

Prior Image Constrained Compressed Sensing Metal Artifact Reduction (PICCS-MAR): 2D and 3D Image Quality Improvement with Hip Prostheses at CT Colonography.

PubMed

Bannas, Peter; Li, Yinsheng; Motosugi, Utaroh; Li, Ke; Lubner, Meghan; Chen, Guang-Hong; Pickhardt, Perry J

2016-07-01

To assess the effect of the prior-image-constrained-compressed-sensing-based metal-artefact-reduction (PICCS-MAR) algorithm on streak artefact reduction and 2D and 3D-image quality improvement in patients with total hip arthroplasty (THA) undergoing CT colonography (CTC). PICCS-MAR was applied to filtered-back-projection (FBP)-reconstructed DICOM CTC-images in 52 patients with THA (unilateral, n = 30; bilateral, n = 22). For FBP and PICCS-MAR series, ROI-measurements of CT-numbers were obtained at predefined levels for fat, muscle, air, and the most severe artefact. Two radiologists independently reviewed 2D and 3D CTC-images and graded artefacts and image quality using a five-point-scale (1 = severe streak/no-diagnostic confidence, 5 = no streak/excellent image-quality, high-confidence). Results were compared using paired and unpaired t-tests and Wilcoxon signed-rank and Mann-Whitney-tests. Streak artefacts and image quality scores for FBP versus PICCS-MAR 2D-images (median: 1 vs. 3 and 2 vs. 3, respectively) and 3D images (median: 2 vs. 4 and 3 vs. 4, respectively) showed significant improvement after PICCS-MAR (all P < 0.001). PICCS-MAR significantly improved the accuracy of mean CT numbers for fat, muscle and the area with the most severe artefact (all P < 0.001). PICCS-MAR substantially reduces streak artefacts related to THA on DICOM images, thereby enhancing visualization of anatomy on 2D and 3D CTC images and increasing diagnostic confidence. • PICCS-MAR significantly reduces streak artefacts associated with total hip arthroplasty on 2D and 3D CTC. • PICCS-MAR significantly improves 2D and 3D CTC image quality and diagnostic confidence. • PICCS-MAR can be applied retrospectively to DICOM images from single-kVp CT.

Diagnostic accuracy of cerebrospinal fluid gram stain in children with suspected bacterial meningitis.

PubMed

Brizzi, Kate; Hines, Elizabeth M; McGowan, Karin L; Shah, Samir S

2012-02-01

This cross-sectional study included 1938 children undergoing lumbar puncture; 21 (1.1%) cases were classified as definite (n = 17) or probable (n = 4) bacterial meningitis. Gram stain sensitivity was 94.1% (95% confidence interval, 71.3%-99.9%) for those with definite meningitis; the positive predictive value was 47.1% (95% confidence interval, 29.8%-64.9%). The sensitivity was 95.2% for those with definite or probable meningitis. Antibiotic pretreatment did not affect results.

A university outbreak of gastroenteritis due to a small round-structured virus. Application of molecular diagnostics to identify the etiologic agent and patterns of transmission.

PubMed

Kilgore, P E; Belay, E D; Hamlin, D M; Noel, J S; Humphrey, C D; Gary, H E; Ando, T; Monroe, S S; Kludt, P E; Rosenthal, D S; Freeman, J; Glass, R I

1996-04-01

An epidemiologic investigation of a gastroenteritis outbreak in December 1994 indicated that salad consumption during lunch was linked with illness on 2 days (5 December: odds ratio [OR]=3.1, 95% confidence interval [CI]=2.0-5.0; 6 December: OR=3.1, 95% CI=1.9-4.9). Single stool or vomitus specimens from ill students and staff (case-patients) were examined for bacterial and viral pathogens. Small round-structured viruses (SRSVs) were detected by electron microscopy in stool specimens from 9 of 19 case-patients and in vomitus specimens from 3 of 5 case-patients. By reverse transcription-polymerase chain reaction (RT-PCR), the SRSVs were shown to be G-2/P2-B type strain. The nucleotide sequences of RT-PCR products from vomitus and stool specimens of ill students were identical to stool specimens from the ill salad chef. These findings suggest that a single SRSV strain was the etiologic agent in the outbreak that was possibly transmitted to students through consumption of contaminated salad. Epidemiologic investigation in conjunction with molecular diagnostics may enable early identification of sources of infection and improve outbreak control.

Diagnosis and management of Pneumocystis jirovecii infection.

PubMed

White, P Lewis; Backx, Matthijs; Barnes, Rosemary A

2017-05-01

Pneumocystis jirovecii is a ubiquitous fungus, which causes pneumonia in humans. Diagnosis was hampered by the inability to culture the organism, and based on microscopic examination of respiratory samples or clinical presentation. New assays can assist in the diagnosis and even aid with the emergence of resistant infections. Areas covered: This manuscript will provide background information on Pneumocystis pneumonia (PcP). Diagnosis, from radiological to non-microbiological (e.g. Lactate dehydrogenase) and microbiological investigations (Microscopy, PCR, β-D-Glucan) will be discussed. Recommendations on prophylactic and therapeutic management will be covered. Expert commentary: PcP diagnosis using microscopy is far from optimal and false negatives will occur. With an incidence of 1% or less, the pre-test probability of not having PcP is 99% and testing is suited to excluding disease. Microscopy provides a high degree of diagnostic confidence but it is not infallible, and its lower sensitivity limits its application. Newer diagnostics (PCR, β-D-Glucan) can aid management and improve performance when testing less invasive specimens, such as upper respiratory samples or blood, alleviating clinical pressure. Combination testing may allow PcP to be both diagnosed and excluded, and molecular testing can assist in the detection of emerging resistant PcP.

Clinical Utility of Amyloid PET Imaging in the Differential Diagnosis of Atypical Dementias and Its Impact on Caregivers.

PubMed

Bensaïdane, Mohamed Reda; Beauregard, Jean-Mathieu; Poulin, Stéphane; Buteau, François-Alexandre; Guimond, Jean; Bergeron, David; Verret, Louis; Fortin, Marie-Pierre; Houde, Michèle; Bouchard, Rémi W; Soucy, Jean-Paul; Laforce, Robert

2016-04-18

Recent studies have supported a role for amyloid positron emission tomography (PET) imaging in distinguishing Alzheimer's disease (AD) pathology from other pathological protein accumulations leading to dementia. We investigated the clinical utility of amyloid PET in the differential diagnosis of atypical dementia cases and its impact on caregivers. Using the amyloid tracer 18F-NAV4694, we prospectively scanned 28 patients (mean age 59.3 y, s.d. 5.8; mean MMSE 21.4, s.d. 6.0) with an atypical dementia syndrome. Following a comprehensive diagnostic workup (i.e., history taking, neurological examination, blood tests, neuropsychological evaluation, MRI, and FDG-PET), no certain diagnosis could be arrived at. Amyloid PET was then conducted and classified as positive or negative. Attending physicians were asked to evaluate whether this result led to a change in diagnosis or altered management. They also reported their degree of confidence in the diagnosis. Caregivers were met after disclosure of amyloid PET results and completed a questionnaire/interview to assess the impact of the scan. Our cohort was evenly divided between positive (14/28) and negative (14/28) 18F-NAV4694 cases. Amyloid PET resulted in a diagnostic change in 9/28 cases (32.1%: 17.8% changed from AD to non-AD, 14.3% from non-AD to AD). There was a 44% increase in diagnostic confidence. Altered management occurred in 71.4% (20/28) of cases. Knowledge of amyloid status improved caregivers' outcomes in all domains (anxiety, depression, disease perception, future anticipation, and quality of life). This study suggests a useful additive role for amyloid PET in atypical cases with an unclear diagnosis beyond the extensive workup of a tertiary memory clinic. Amyloid PET increased diagnostic confidence and led to clinically significant alterations in management. The information gained from that test was well received by caregivers and encouraged spending quality time with their loved ones.

Toward diagnostic and phenotype markers for genetically transmitted speech delay.

PubMed

Shriberg, Lawrence D; Lewis, Barbara A; Tomblin, J Bruce; McSweeny, Jane L; Karlsson, Heather B; Scheer, Alison R

2005-08-01

Converging evidence supports the hypothesis that the most common subtype of childhood speech sound disorder (SSD) of currently unknown origin is genetically transmitted. We report the first findings toward a set of diagnostic markers to differentiate this proposed etiological subtype (provisionally termed speech delay-genetic) from other proposed subtypes of SSD of unknown origin. Conversational speech samples from 72 preschool children with speech delay of unknown origin from 3 research centers were selected from an audio archive. Participants differed on the number of biological, nuclear family members (0 or 2+) classified as positive for current and/or prior speech-language disorder. Although participants in the 2 groups were found to have similar speech competence, as indexed by their Percentage of Consonants Correct scores, their speech error patterns differed significantly in 3 ways. Compared with children who may have reduced genetic load for speech delay (no affected nuclear family members), children with possibly higher genetic load (2+ affected members) had (a) a significantly higher proportion of relative omission errors on the Late-8 consonants; (b) a significantly lower proportion of relative distortion errors on these consonants, particularly on the sibilant fricatives /s/, /z/, and //; and (c) a significantly lower proportion of backed /s/ distortions, as assessed by both perceptual and acoustic methods. Machine learning routines identified a 3-part classification rule that included differential weightings of these variables. The classification rule had diagnostic accuracy value of 0.83 (95% confidence limits = 0.74-0.92), with positive and negative likelihood ratios of 9.6 (95% confidence limits = 3.1-29.9) and 0.40 (95% confidence limits = 0.24-0.68), respectively. The diagnostic accuracy findings are viewed as promising. The error pattern for this proposed subtype of SSD is viewed as consistent with the cognitive-linguistic processing deficits that have been reported for genetically transmitted verbal disorders.

Potential impact of amyloid imaging on diagnosis and intended management in patients with progressive cognitive decline.

PubMed

Grundman, Michael; Pontecorvo, Michael J; Salloway, Stephen P; Doraiswamy, P Murali; Fleisher, Adam S; Sadowsky, Carl H; Nair, Anil K; Siderowf, Andrew; Lu, Ming; Arora, Anupa K; Agbulos, Abigail; Flitter, Matthew L; Krautkramer, Michael J; Sarsour, Khaled; Skovronsky, Daniel M; Mintun, Mark A

2013-01-01

Florbetapir F18 has been approved by the Food and Drug Administration for in vivo assessment of amyloid pathology in patients undergoing evaluation for Alzheimer disease (AD). The aim of this study was to determine the impact of amyloid imaging on the diagnoses and management of patients undergoing evaluation for cognitive decline. Patients were recruited to participate at 19 clinical sites. The site physician provided a provisional diagnosis, an estimate of their diagnostic confidence, and their plan for diagnostic evaluation and management both before and after receiving the results from amyloid imaging with florbetapir F18. Analyses compared the frequency of AD and non-AD diagnoses, plans for ancillary testing, and intended patient management before and after florbetapir imaging. A total of 229 patients participated in the trial (113 amyloid positive, 116 amyloid negative). After receiving the results of the florbetapir scan, diagnosis changed in 125/229, or 54.6% [95% confidence intervals (CI), 48.1%-60.9%], of cases, and diagnostic confidence increased by an average of 21.6% (95% CI, 18.3%-24.8%). A total of 199/229 or 86.9% (95% CI, 81.9%-90.7%) of cases had at least 1 change in their management plan. Intended cholinesterase inhibitor or memantine treatment increased by 17.7% (95% CI, 11.8%-25.8%) of all cases with positive scans and decreased by 23.3% (95% CI, 16.5%-31.8%) of all those with negative scans. Among subjects who had not yet undergone a completed work up, planned brain structural imaging (computed tomographic/magnetic resonance imaging) decreased by 24.4% (95% CI, 17.5%-32.8%) and planned neuropsychological testing decreased by 32.8% (95% CI, 25.0%-41.6%). In summary, amyloid imaging results altered physician's diagnostic thinking, intended testing, and management of patients undergoing evaluation for cognitive decline.

Diagnostic Reasoning for ST-Segment Elevation Myocardial Infarction (STEMI) Interpretation Is Preserved Despite Fatigue

PubMed Central

Kellogg, Adam R.; Coute, Ryan A.; Garra, Gregory

2015-01-01

Background Fatigue and sleepiness contribute to medical errors, although the effect of circadian disruption and fatigue on diagnostic reasoning skills is largely unknown. Objective To determine whether circadian disruption and fatigue negatively affect the emergency medicine (EM) resident's ability to make important clinical decisions based on electrocardiogram (ECG) interpretation. Methods Senior EM residents at 2 programs completed a questionnaire consisting of various measures of fatigue followed by an ECG test packet of ST-segment elevation myocardial infarction (STEMI) and STEMI mimics. Participants were asked to examine each ECG and determine whether cardiac catheterization laboratory activation (CLA) was indicated, and to report their confidence in their decision making on an 11-point, numeric rating scale. The primary outcome measured was a pairwise difference in accuracy of CLA between daytime and overnight testing. Results A total of 23 residents were enrolled in 2011 and 2012. Subjects demonstrated significant differences in multiple measures of sleepiness and fatigue during overnight periods. The median (interquartile range [IQR]) accuracy of CLA was not significantly different between daytime and overnight (70% [IQR, 50–80] versus 70% [IQR, 60–70], P  =  .82). There were no significant differences in the median number of overcalls (CLA when not a STEMI) and undercalls (no CLA when a STEMI was present; P  =  .57 and .37, respectively). Diagnostic confidence and confidence in CLA were not statistically different between daytime and overnight. Conclusions Despite a measurable degree of fatigue, senior EM residents experienced no decrease in their ability to accurately make CLA decisions based on ECG interpretation. PMID:26217418

Diagnostic Reasoning for ST-Segment Elevation Myocardial Infarction (STEMI) Interpretation Is Preserved Despite Fatigue.

PubMed

Kellogg, Adam R; Coute, Ryan A; Garra, Gregory

2015-03-01

Fatigue and sleepiness contribute to medical errors, although the effect of circadian disruption and fatigue on diagnostic reasoning skills is largely unknown. To determine whether circadian disruption and fatigue negatively affect the emergency medicine (EM) resident's ability to make important clinical decisions based on electrocardiogram (ECG) interpretation. Senior EM residents at 2 programs completed a questionnaire consisting of various measures of fatigue followed by an ECG test packet of ST-segment elevation myocardial infarction (STEMI) and STEMI mimics. Participants were asked to examine each ECG and determine whether cardiac catheterization laboratory activation (CLA) was indicated, and to report their confidence in their decision making on an 11-point, numeric rating scale. The primary outcome measured was a pairwise difference in accuracy of CLA between daytime and overnight testing. A total of 23 residents were enrolled in 2011 and 2012. Subjects demonstrated significant differences in multiple measures of sleepiness and fatigue during overnight periods. The median (interquartile range [IQR]) accuracy of CLA was not significantly different between daytime and overnight (70% [IQR, 50-80] versus 70% [IQR, 60-70], P  =  .82). There were no significant differences in the median number of overcalls (CLA when not a STEMI) and undercalls (no CLA when a STEMI was present; P  =  .57 and .37, respectively). Diagnostic confidence and confidence in CLA were not statistically different between daytime and overnight. Despite a measurable degree of fatigue, senior EM residents experienced no decrease in their ability to accurately make CLA decisions based on ECG interpretation.

Validity and applicability of a new recording method for hypertension.

PubMed

Mas-Heredia, Minerva; Molés-Moliner, Eloisa; González-de Paz, Luis; Kostov, Belchin; Ortiz-Molina, Jacinto; Mauri-Vázquez, Vanesa; Menacho-Pascual, Ignacio; Cararach-Salami, Daniel; Sierra-Benito, Cristina; Sisó-Almirall, Antoni

2014-09-01

Blood pressure measurement methods and conditions are determinants of hypertension diagnosis. A recent British guideline recommends systematic 24-h ambulatory blood pressure monitoring. However, these devices are not available at all health centers and they can only be used by 1 patient per day. The aim of this study was to test a new blood pressure recording method to see if it gave the same diagnostic results as 24-h blood pressure monitoring. One-hour blood pressure monitoring under routine clinical practice conditions was compared with standard method of day time recording by analyzing the coefficient of correlation and Bland-Altman plots. The Kappa index was used to calculate degree of agreement. Method sensitivity and specificity were also analyzed. Of the 102 participants, 89 (87.3%) obtained the same diagnosis regardless of method, with high between-method agreement (κ= 0.81; 95% confidence interval, 0.71-0.91). We observed robust correlations between diastolic (r=0.85) and systolic blood pressure (r=0.76) readings. Sensitivity and specificity for the new method for diagnosing white coat hypertension were 85.2% (95% confidence interval 67.5%-94.1%) and 92% (95% confidence interval, 83.6%-96.3%), respectively. One-hour blood pressure monitoring is a valid and reliable method for diagnosing hypertension and for classifying hypertension subpopulations, especially in white coat hypertension and refractory hypertension. This also leads to a more productive use of monitoring instruments. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Generalized anxiety disorder prevalence and comorbidity with depression in coronary heart disease: a meta-analysis.

PubMed

Tully, Phillip J; Cosh, Suzanne M

2013-12-01

Generalized anxiety disorder prevalence and comorbidity with depression in coronary heart disease patients remain unquantified. Systematic searching of Medline, Embase, SCOPUS and PsycINFO databases revealed 1025 unique citations. Aggregate generalized anxiety disorder prevalence (12 studies, N = 3485) was 10.94 per cent (95% confidence interval: 7.8-13.99) and 13.52 per cent (95% confidence interval: 8.39-18.66) employing Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria (random effects). Lifetime generalized anxiety disorder prevalence was 25.80 per cent (95% confidence interval: 20.84-30.77). In seven studies, modest correlation was evident between generalized anxiety disorder and depression, Fisher's Z = .30 (95% confidence interval: .19-.42), suggesting that each psychiatric disorder is best conceptualized as contributing unique variance to coronary heart disease prognosis.

Comparative Diagnostic Performance of Ultrasonography and 99mTc-Sestamibi Scintigraphy for Parathyroid Adenoma in Primary Hyperparathyroidism; Systematic Review and Meta- Analysis

PubMed

Nafisi Moghadam, Reza; Amlelshahbaz, Amir Pasha; Namiranian, Nasim; Sobhan-Ardekani, Mohammad; Emami-Meybodi, Mahmood; Dehghan, Ali; Rahmanian, Masoud; Razavi-Ratki, Seid Kazem

2017-12-28

Objective: Ultrasonography (US) and parathyroid scintigraphy (PS) with 99mTc-MIBI are common methods for preoperative localization of parathyroid adenomas but there discrepancies exist with regard to diagnostic accuracy. The aim of the study was to compare PS and US for localization of parathyroid adenoma with a systematic review and meta-analysis of the literature. Methods: Pub Med, Scopus (EMbase), Web of Science and the reference lists of all included studies were searched up to 1st January 2016. The search strategy was according PICO characteristics. Heterogeneity between the studies was accounted by P < 0.1. Point estimates were pooled estimate of sensitivity, specificity and positive predictive value of SPECT and ultrasonography with 99% confidence intervals (CIs) by pooling available data. Data analysis was performed using Meta-DiSc software (version 1.4). Results: Among 188 studies and after deletion of duplicated studies (75), a total of 113 titles and abstracts were studied. From these, 12 studies were selected. The meta-analysis determined a pooled sensitivity for scintigraphy of 83% [99% confidence interval (CI) 96.358 -97.412] and for ultra-sonography of 80% [99% confidence interval (CI) 76-83]. Similar results for specificity were also obtained for both approache. Conclusion: According this meta- analysis, there were no significant differences between the two methods in terms of sensitivity and specificity. There were overlaps in 99% confidence intervals. Also features of the two methods are similar. Creative Commons Attribution License

Test Accuracy of Informant-Based Cognitive Screening Tests for Diagnosis of Dementia and Multidomain Cognitive Impairment in Stroke.

PubMed

McGovern, Aine; Pendlebury, Sarah T; Mishra, Nishant K; Fan, Yuhua; Quinn, Terence J

2016-02-01

Poststroke cognitive assessment can be performed using standardized questionnaires designed for family or care givers. We sought to describe the test accuracy of such informant-based assessments for diagnosis of dementia/multidomain cognitive impairment in stroke. We performed a systematic review using a sensitive search strategy across multidisciplinary electronic databases. We created summary test accuracy metrics and described reporting and quality using STARDdem and Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tools, respectively. From 1432 titles, we included 11 studies. Ten papers used the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE). Four studies described IQCODE for diagnosis of poststroke dementia (n=1197); summary sensitivity: 0.81 (95% confidence interval, 0.60-0.93); summary specificty: 0.83 (95% confidence interval, 0.64-0.93). Five studies described IQCODE as tool for predicting future dementia (n=837); summary sensitivity: 0.60 (95% confidence interval, 0.32-0.83); summary specificity: 0.97 (95% confidence interval, 0.70-1.00). All papers had issues with at least 1 aspect of study reporting or quality. There is a limited literature on informant cognitive assessments in stroke. IQCODE as a diagnostic tool has test properties similar to other screening tools, IQCODE as a prognostic tool is specific but insensitive. We found no papers describing test accuracy of informant tests for diagnosis of prestroke cognitive decline, few papers on poststroke dementia and all included papers had issues with potential bias. © 2015 American Heart Association, Inc.

LDRD Final Review: Radiation Transport Calculations

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

Goorley, John Timothy; Morgan, George Lake; Lestone, John Paul

2017-06-22

Both high-fidelity & toy simulations are being used to understand measured signals and improve the Area 11 NDSE diagnostic. We continue to gain more and more confidence in the ability for MCNP to simulate neutron and photon transport from source to radiation detector.

Detection of prostate cancer with multiparametric MRI (mpMRI): effect of dedicated reader education on accuracy and confidence of index and anterior cancer diagnosis

PubMed Central

Garcia-Reyes, Kirema; Passoni, Niccolò M.; Palmeri, Mark L.; Kauffman, Christopher R.; Choudhury, Kingshuk Roy; Polascik, Thomas J.; Gupta, Rajan T.

2015-01-01

Purpose To evaluate the impact of dedicated reader education on accuracy/confidence of peripheral zone index cancer and anterior prostate cancer (PCa) diagnosis with mpMRI; secondary aim was to assess the ability of readers to differentiate low-grade cancer (Gleason 6 or below) from high-grade cancer (Gleason 7+). Materials and methods Five blinded radiology fellows evaluated 31 total prostate mpMRIs in this IRB-approved, HIPAA-compliant, retrospective study for index lesion detection, confidence in lesion diagnosis (1–5 scale), and Gleason grade (Gleason 6 or lower vs. Gleason 7+). Following a dedicated education program, readers reinterpreted cases after a memory extinction period, blinded to initial reads. Reference standard was established combining whole mount histopathology with mpMRI findings by a board-certified radiologist with 5 years of prostate mpMRI experience. Results Index cancer detection: pre-education accuracy 74.2%; post-education accuracy 87.7% (p = 0.003). Confidence in index lesion diagnosis: pre-education 4.22 ± 1.04; post-education 3.75 ± 1.41 (p = 0.0004). Anterior PCa detection: pre-education accuracy 54.3%; post-education accuracy 94.3% (p = 0.001). Confidence in anterior PCa diagnosis: pre-education 3.22 ± 1.54; post-education 4.29 ± 0.83 (p = 0.0003). Gleason score accuracy: pre-education 54.8%; post-education 73.5% (p = 0.0005). Conclusions A dedicated reader education program on PCa detection with mpMRI was associated with a statistically significant increase in diagnostic accuracy of index cancer and anterior cancer detection as well as Gleason grade identification as compared to pre-education values. This was also associated with a significant increase in reader diagnostic confidence. This suggests that substantial interobserver variability in mpMRI interpretation can potentially be reduced with a focus on education and that this can occur over a fellowship training year. PMID:25034558

Isolation of RNA From Peripheral Blood Cells: A Validation Study for Molecular Diagnostics by Microarray and Kinetic RT-PCR Assays - Application in Aerospace Medicine

DTIC Science & Technology

2004-01-01

of RNA From Peripheral Blood Cells: A Validation Study for Molecular Diagnostics by Microarray and Kinetic RT-PCR Assays  Application in...VALIDATION STUDY FOR MOLECULAR DIAGNOSTICS BY MICROARRAY AND KINETIC RT-PCR ASSAYS  APPLICATION IN AEROSPACE MEDICINE INTRODUCTION Extraction of cellular

Geriatric teledermatology: store-and-forward vs. face-to-face examination.

PubMed

Rubegni, P; Nami, N; Cevenini, G; Poggiali, S; Hofmann-Wellenhof, R; Massone, C; Bilenchi, R; Bartalini, M; Cappelli, R; Fimiani, M

2011-11-01

Telemedicine could be useful in countries like Italy to meet the needs of elderly patients and in particular in those in precarious general conditions, for whom travelling even short distances can pose considerable practical and economical difficulties. The aim of this study was to determine the efficacy of store-and-forward teledermatology vs face-to-face consultations in elderly patients. A total of 130 geriatric patients with skin diseases requiring dermatological examination were enrolled. The patients examined, consisting of 60 men (46.15%) and 70 women (53.85%), were aged between 66 and 97 years (mean age 80.58 years). Three dermatologists of the department, with equal experience took turns in face-to-face examination and teledermatology (store-and-forward). To compare face-to-face dermatological examinations with the asynchronous store-and-forward approach of teledermatology, we considered diagnostic agreement (ICD-9 code), therapeutic agreement and concordance of diagnostic confidence. One hundred and fourteen of 130 patients were diagnosed with the same ICD-9 code, making a total observed agreement of 87.7% with a Cohen's κ estimated of 0.863. Agreement between therapies was 69.6% (Cohen's κ = 0.640). As it concerns diagnostic confidence, dermatologists appeared generally slightly less certain of their diagnosis by telemedicine. Store-and-forward teledermatology can improve diagnostic and therapeutic care for skin disease in elderly who lack easy and/or direct access to dermatologists. © 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.

High sensitivity and specificity in proposed clinical diagnostic criteria for anti-N-methyl-D-aspartate receptor encephalitis.

PubMed

Ho, Alvin C C; Mohammad, Shekeeb S; Pillai, Sekhar C; Tantsis, Esther; Jones, Hannah; Ho, Reena; Lim, Ming; Hacohen, Yael; Vincent, Angela; Dale, Russell C

2017-12-01

To determine the validity of the proposed clinical diagnostic criteria for anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis in paediatric patients. The diagnostic criteria for anti-NMDAR encephalitis proposed by Graus et al. (2016) use clinical features and conventional investigations to facilitate early immunotherapy before antibody status is available. The criteria are satisfied if patients develop four out of six symptom groups within 3 months, together with at least one abnormal investigation (electroencephalography/cerebrospinal fluid) and reasonable exclusion of other disorders. We evaluated the validity of the criteria using a retrospective cohort of paediatric patients with encephalitis. Twenty-nine patients with anti-NMDAR encephalitis and 74 comparison children with encephalitis were included. As expected, the percentage of patients with anti-NMDAR encephalitis who fulfilled the clinical criteria increased over time. During the hospital inpatient admission, most patients (26/29, 90%) with anti-NMDAR encephalitis fulfilled the criteria, significantly more than the comparison group (3/74, 4%) (p<0.001). The median time of fulfilling the criteria in patients with anti-NMDAR encephalitis was 2 weeks from first symptom onset (range 1-6). The sensitivity of the criteria was 90% (95% confidence interval 73-98) and the specificity was 96% (95% confidence interval 89-99). The proposed diagnostic criteria for anti-NMDAR encephalitis have good sensitivity and specificity. Incomplete criteria do not exclude the diagnosis. The proposed clinical diagnostic criteria for anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis by Graus et al. (2016) have high sensitivity and specificity in paediatric patients. The median time of fulfilling the criteria in patients with anti-NMDAR was 2 weeks from first symptom onset. © 2017 Mac Keith Press.

METACOGNITIVE SCAFFOLDS IMPROVE SELF-JUDGMENTS OF ACCURACY IN A MEDICAL INTELLIGENT TUTORING SYSTEM

PubMed Central

Feyzi-Behnagh, Reza; Azevedo, Roger; Legowski, Elizabeth; Reitmeyer, Kayse; Tseytlin, Eugene; Crowley, Rebecca S.

2013-01-01

In this study, we examined the effect of two metacognitive scaffolds on the accuracy of confidence judgments made while diagnosing dermatopathology slides in SlideTutor. Thirty-one (N = 31) first- to fourth-year pathology and dermatology residents were randomly assigned to one of the two scaffolding conditions. The cases used in this study were selected from the domain of Nodular and Diffuse Dermatitides. Both groups worked with a version of SlideTutor that provided immediate feedback on their actions for two hours before proceeding to solve cases in either the Considering Alternatives or Playback condition. No immediate feedback was provided on actions performed by participants in the scaffolding mode. Measurements included learning gains (pre-test and post-test), as well as metacognitive performance, including Goodman-Kruskal Gamma correlation, bias, and discrimination. Results showed that participants in both conditions improved significantly in terms of their diagnostic scores from pre-test to post-test. More importantly, participants in the Considering Alternatives condition outperformed those in the Playback condition in the accuracy of their confidence judgments and the discrimination of the correctness of their assertions while solving cases. The results suggested that presenting participants with their diagnostic decision paths and highlighting correct and incorrect paths helps them to become more metacognitively accurate in their confidence judgments. PMID:24532850

METACOGNITIVE SCAFFOLDS IMPROVE SELF-JUDGMENTS OF ACCURACY IN A MEDICAL INTELLIGENT TUTORING SYSTEM.

PubMed

Feyzi-Behnagh, Reza; Azevedo, Roger; Legowski, Elizabeth; Reitmeyer, Kayse; Tseytlin, Eugene; Crowley, Rebecca S

2014-03-01

In this study, we examined the effect of two metacognitive scaffolds on the accuracy of confidence judgments made while diagnosing dermatopathology slides in SlideTutor. Thirty-one ( N = 31) first- to fourth-year pathology and dermatology residents were randomly assigned to one of the two scaffolding conditions. The cases used in this study were selected from the domain of Nodular and Diffuse Dermatitides. Both groups worked with a version of SlideTutor that provided immediate feedback on their actions for two hours before proceeding to solve cases in either the Considering Alternatives or Playback condition. No immediate feedback was provided on actions performed by participants in the scaffolding mode. Measurements included learning gains (pre-test and post-test), as well as metacognitive performance, including Goodman-Kruskal Gamma correlation, bias, and discrimination. Results showed that participants in both conditions improved significantly in terms of their diagnostic scores from pre-test to post-test. More importantly, participants in the Considering Alternatives condition outperformed those in the Playback condition in the accuracy of their confidence judgments and the discrimination of the correctness of their assertions while solving cases. The results suggested that presenting participants with their diagnostic decision paths and highlighting correct and incorrect paths helps them to become more metacognitively accurate in their confidence judgments.

Optimal Monochromatic Energy Levels in Spectral CT Pulmonary Angiography for the Evaluation of Pulmonary Embolism

PubMed Central

Wu, Huawei; Zhang, Qing; Hua, Jia; Hua, Xiaolan; Xu, Jianrong

2013-01-01

Background The aim of this study was to determine the optimal monochromatic spectral CT pulmonary angiography (sCTPA) levels to obtain the highest image quality and diagnostic confidence for pulmonary embolism detection. Methods The Institutional Review Board of the Shanghai Jiao Tong University School of Medicine approved this study, and written informed consent was obtained from all participating patients. Seventy-two patients with pulmonary embolism were scanned with spectral CT mode in the arterial phase. One hundred and one sets of virtual monochromatic spectral (VMS) images were generated ranging from 40 keV to 140 keV. Image noise, clot diameter and clot to artery contrast-to-noise ratio (CNR) from seven sets of VMS images at selected monochromatic levels in sCTPA were measured and compared. Subjective image quality and diagnostic confidence for these images were also assessed and compared. Data were analyzed by paired t test and Wilcoxon rank sum test. Results The lowest noise and the highest image quality score for the VMS images were obtained at 65 keV. The VMS images at 65 keV also had the second highest CNR value behind that of 50 keV VMS images. There was no difference in the mean noise and CNR between the 65 keV and 70 keV VMS images. The apparent clot diameter correlated with the keV levels. Conclusions The optimal energy level for detecting pulmonary embolism using dual-energy spectral CT pulmonary angiography was 65–70 keV. Virtual monochromatic spectral images at approximately 65–70 keV yielded the lowest image noise, high CNR and highest diagnostic confidence for the detection of pulmonary embolism. PMID:23667583

Defining Characteristics of Diagnostic Classification Models and the Problem of Retrofitting in Cognitive Diagnostic Assessment

ERIC Educational Resources Information Center

Gierl, Mark J.; Cui, Ying

2008-01-01

One promising application of diagnostic classification models (DCM) is in the area of cognitive diagnostic assessment in education. However, the successful application of DCM in educational testing will likely come with a price--and this price may be in the form of new test development procedures and practices required to yield data that satisfy…

Facilitated Diagnosis of Pneumothoraces in Newborn Mice Using X-ray Dark-Field Radiography.

PubMed

Hellbach, Katharina; Yaroshenko, Andre; Willer, Konstantin; Pritzke, Tina; Baumann, Alena; Hesse, Nina; Auweter, Sigrid; Reiser, Maximilian F; Eickelberg, Oliver; Pfeiffer, Franz; Hilgendorff, Anne; Meinel, Felix G

2016-10-01

The aim of this study was to evaluate the diagnostic value of x-ray dark-field imaging in projection radiography-based depiction of pneumothoraces in the neonatal murine lung, a potentially life-threatening medical condition that requires a timely and correct diagnosis. By the use of a unique preclinical model, 7-day-old C57Bl/6N mice received mechanical ventilation for 2 or 8 hours with oxygen-rich gas (FIO2 = 0.4; n = 24). Unventilated mice either spontaneously breathed oxygen-rich gas (FIO2 = 0.4) for 2 or 8 hours or room air (n = 22). At the end of the experiment, lungs were inflated with a standardized volume of air after a lethal dose of pentobarbital was administered to the pups. All lungs were imaged with a prototype grating-based small-animal scanner to acquire x-ray transmission and dark-field radiographs. Image contrast between the air-filled pleural space and lung tissue was quantified for both transmission and dark-field radiograms. After the independent expert's assessment, 2 blinded readers evaluated all dark-field and transmission images for the presence or absence of pneumothoraces. Contrast ratios, diagnostic accuracy, as well as reader's confidence and interreader agreement were recorded for both imaging modalities. Evaluation of both x-ray transmission and dark-field radiographs by independent experts revealed the development of a total of 10 pneumothoraces in 8 mice. Here, the contrast ratio between the air-filled pleural space of the pneumothoraces and the lung tissue was significantly higher in the dark field (8.4 ± 3.5) when compared with the transmission images (5.1 ± 2.8; P < 0.05). Accordingly, the readers' diagnostic confidence for the diagnosis of pneumothoraces was significantly higher for dark-field compared with transmission images (P = 0.001). Interreader agreement improved from moderate for the analysis of transmission images alone (κ = 0.41) to very good when analyzing dark-field images alone (κ = 0.90) or in combination with transmission images (κ = 0.88). Diagnostic accuracy significantly improved for the analysis of dark-field images alone (P = 0.04) or in combination with transmission images (P = 0.02), compared with the analysis of transmission radiographs only. The significant improvement in contrast ratios between lung parenchyma and free air in the dark-field images allows the facilitated detection of pneumothoraces in the newborn mouse. These preclinical experiments indicate the potential of the technique for future clinical applications.

Reflectometric measurement of plasma imaging and applications

NASA Astrophysics Data System (ADS)

Mase, A.; Ito, N.; Oda, M.; Komada, Y.; Nagae, D.; Zhang, D.; Kogi, Y.; Tobimatsu, S.; Maruyama, T.; Shimazu, H.; Sakata, E.; Sakai, F.; Kuwahara, D.; Yoshinaga, T.; Tokuzawa, T.; Nagayama, Y.; Kawahata, K.; Yamaguchi, S.; Tsuji-Iio, S.; Domier, C. W.; Luhmann, N. C., Jr.; Park, H. K.; Yun, G.; Lee, W.; Padhi, S.; Kim, K. W.

2012-01-01

Progress in microwave and millimeter-wave technologies has made possible advanced diagnostics for application to various fields, such as, plasma diagnostics, radio astronomy, alien substance detection, airborne and spaceborne imaging radars called as synthetic aperture radars, living body measurements. Transmission, reflection, scattering, and radiation processes of electromagnetic waves are utilized as diagnostic tools. In this report we focus on the reflectometric measurements and applications to biological signals (vital signal detection and breast cancer detection) as well as plasma diagnostics, specifically by use of imaging technique and ultra-wideband radar technique.

Clinical diagnosis of partial or complete anterior cruciate ligament tears using patients' history elements and physical examination tests

PubMed Central

Fallaha, Michel; Belzile, Sylvain; Martel-Pelletier, Johanne; Pelletier, Jean-Pierre; Feldman, Debbie; Sylvestre, Marie-Pierre; Vendittoli, Pascal-André; Desmeules, François

2018-01-01

Objective To assess the diagnostic validity of clusters combining history elements and physical examination tests to diagnose partial or complete anterior cruciate ligament (ACL) tears. Design Prospective diagnostic study. Settings Orthopaedic clinics (n = 2), family medicine clinics (n = 2) and community-dwelling. Participants Consecutive patients with a knee complaint (n = 279) and consulting one of the participating orthopaedic surgeons (n = 3) or sport medicine physicians (n = 2). Interventions Not applicable. Main outcome measures History elements and physical examination tests performed independently were compared to the reference standard: an expert physicians’ composite diagnosis including history elements, physical tests and confirmatory magnetic resonance imaging. Penalized logistic regression (LASSO) was used to identify history elements and physical examination tests associated with the diagnosis of ACL tear and recursive partitioning was used to develop diagnostic clusters. Diagnostic accuracy measures including sensitivity (Se), specificity (Sp), predictive values and positive and negative likelihood ratios (LR+/-) with associated 95% confidence intervals (CI) were calculated. Results Forty-three individuals received a diagnosis of partial or complete ACL tear (15.4% of total cohort). The Lachman test alone was able to diagnose partial or complete ACL tears (LR+: 38.4; 95%CI: 16.0–92.5). Combining a history of trauma during a pivot with a “popping” sensation also reached a high diagnostic validity for partial or complete tears (LR+: 9.8; 95%CI: 5.6–17.3). Combining a history of trauma during a pivot, immediate effusion after trauma and a positive Lachman test was able to identify individuals with a complete ACL tear (LR+: 17.5; 95%CI: 9.8–31.5). Finally, combining a negative history of pivot or a negative popping sensation during trauma with a negative Lachman or pivot shift test was able to exclude both partial or complete ACL tears (LR-: 0.08; 95%CI: 0.03–0.24). Conclusion Diagnostic clusters combining history elements and physical examination tests can support the differential diagnosis of ACL tears compared to various knee disorders. PMID:29894492

Artificial Intelligence in Medical Practice: The Question to the Answer?

PubMed

Miller, D Douglas; Brown, Eric W

2018-02-01

Computer science advances and ultra-fast computing speeds find artificial intelligence (AI) broadly benefitting modern society-forecasting weather, recognizing faces, detecting fraud, and deciphering genomics. AI's future role in medical practice remains an unanswered question. Machines (computers) learn to detect patterns not decipherable using biostatistics by processing massive datasets (big data) through layered mathematical models (algorithms). Correcting algorithm mistakes (training) adds to AI predictive model confidence. AI is being successfully applied for image analysis in radiology, pathology, and dermatology, with diagnostic speed exceeding, and accuracy paralleling, medical experts. While diagnostic confidence never reaches 100%, combining machines plus physicians reliably enhances system performance. Cognitive programs are impacting medical practice by applying natural language processing to read the rapidly expanding scientific literature and collate years of diverse electronic medical records. In this and other ways, AI may optimize the care trajectory of chronic disease patients, suggest precision therapies for complex illnesses, reduce medical errors, and improve subject enrollment into clinical trials. Copyright © 2018 Elsevier Inc. All rights reserved.

Interactive NMR: A Simulation Based Teaching Tool for Fundamentals to Applications with Tangible Analogies

NASA Astrophysics Data System (ADS)

Griesse-Nascimento, Sarah; Bridger, Joshua; Brown, Keith; Westervelt, Robert

2011-03-01

Interactive computer simulations increase students' understanding of difficult concepts and their ability to explain complex ideas. We created a module of eight interactive programs and accompanying lesson plans for teaching the fundamental concepts of Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) that we call interactive NMR (iNMR). We begin with an analogy between nuclear spins and metronomes to start to build intuition about the dynamics of spins in a magnetic field. We continue to explain T1, T2, and pulse sequences with the metronome analogy. The final three programs are used to introduce and explain the Magnetic Resonance Switch, a recent diagnostic technique based on NMR. A modern relevant application is useful to generate interest in the topic and confidence in the students' ability to apply their knowledge. The iNMR module was incorporated into a high school AP physics class. In a preliminary evaluation of implementation, students expressed enthusiasm and demonstrated enhanced understanding of the material relative to the previous year. Funded by NSF PHY-0646094 grant.

Black-blood thrombus imaging (BTI): a contrast-free cardiovascular magnetic resonance approach for the diagnosis of non-acute deep vein thrombosis.

PubMed

Xie, Guoxi; Chen, Hanwei; He, Xueping; Liang, Jianke; Deng, Wei; He, Zhuonan; Ye, Yufeng; Yang, Qi; Bi, Xiaoming; Liu, Xin; Li, Debiao; Fan, Zhaoyang

2017-01-18

Deep vein thrombosis (DVT) is a common but elusive illness that can result in long-term disability or death. Accurate detection of thrombosis and assessment of its size and distribution are critical for treatment decision-making. In the present study, we sought to develop and evaluate a cardiovascular magnetic resonance (CMR) black-blood thrombus imaging (BTI) technique, based on delay alternating with nutation for tailored excitation black-blood preparation and variable flip angle turbo-spin-echo readout, for the diagnosis of non-acute DVT. METHODS: This prospective study was approved by institutional review board and informed consent obtained from all subjects. BTI was first conducted in 11 healthy subjects for parameter optimization and then conducted in 18 non-acute DVT patients to evaluate its diagnostic performance. Two clinically used CMR techniques, contrast-enhanced CMR venography (CE-MRV) and three dimensional magnetization prepared rapid acquisition gradient echo (MPRAGE), were also conducted in all patients for comparison. All images obtained from patients were analyzed on a per-segment basis. Using the consensus diagnosis of CE-MRV as the reference, the sensitivity (SE), specificity (SP), positive and negative predictive values (PPV and NPV), and accuracy (ACC) of BTI and MPRAGE as well as their diagnostic agreement with CE-MRV were calculated. Besides, diagnostic confidence and interreader diagnostic agreement were evaluated for all three techniques. BTI with optimized parameters effectively nulled the venous blood flow signal and allowed directly visualizing the thrombus within the black-blood lumen. Higher SE (90.4% vs 67.6%), SP (99.0% vs. 97.4%), PPV (95.4% vs. 85.6%), NPV (97.8% vs 92.9%) and ACC (97.4% vs. 91.8%) were obtained by BTI in comparison with MPRAGE. Good diagnostic confidence and excellent diagnostic and interreader agreements were achieved by BTI, which were superior to MPRAGE on detecting the chronic thrombus. BTI allows direct visualization of non-acute DVT within the dark venous lumen and has the potential to be a reliable diagnostic tool without the use of contrast medium.

[The experience of implementation of system of quality management in the Department of Laboratory Diagnostic of the N.V. Sklifosofskiy Research Institute of Emergency Care of Moscow Health Department: a lecture].

PubMed

Zenina, L P; Godkov, M A

2013-08-01

The article presents the experience of implementation of system of quality management into the practice of multi-field laboratory of emergency medical care hospital. The analysis of laboratory errors is applied and the modes of their prevention are demonstrated. The ratings of department of laboratory diagnostic of the N. V. Sklifosofskiy research institute of emergency care in the program EQAS (USA) Monthly Clinical Chemistry from 2007 are presented. The implementation of the system of quality management of laboratory analysis into department of laboratory diagnostic made it possible to support physicians of clinical departments with reliable information. The confidence of clinicians to received results increased. The effectiveness of laboratory diagnostic increased due to lowering costs of analysis without negative impact to quality of curative process.

Evaluation of dual-color fluorescence in situ hybridization with peptide nucleic acid probes for the detection of Mycobacterium tuberculosis and non-tuberculous mycobacteria in clinical specimens.

PubMed

Kim, Namhee; Lee, Seung Hee; Yi, Jongyoun; Chang, Chulhun L

2015-09-01

Peptide nucleic acid (PNA) probes are artificial DNA analogues with a hydrophobic nature that can penetrate the mycobacterial cell wall. We evaluated a FISH method for simultaneous detection and identification of Mycobacterium tuberculosis (MTB) and non-tuberculous mycobacteria (NTM) in clinical respiratory specimens using differentially labeled PNA probes. PNA probes targeting the mycobacterial 16S ribosomal RNA were synthesized. The cross-reactivity of MTB- and NTM-specific probes was examined with reference strains and 10 other frequently isolated bacterial species. A total of 140 sputum specimens were analyzed, comprising 100 MTB-positive specimens, 21 NTM-positive specimens, and 19 MTB/NTM-negative specimens; all of them were previously confirmed by PCR and culture. The PNA FISH test results were graded by using the United States Centers for Disease Control and Prevention-recommended scale and compared with the results from the fluorochrome acid-fast bacterial stain. The MTB- and NTM-specific PNA probes showed no cross-reactivity with other tested bacterial species. The test results demonstrated 82.9% agreement with the culture results with diagnostic sensitivity of 80.2% and diagnostic specificity of 100.0% (kappa=0.52, 95% confidence interval: 0.370-0.676). Dual-color PNA FISH showed high specificity for detecting and identifying mycobacteria in clinical specimens. However, because of its relatively low sensitivity, this method could be more applicable to culture confirmation. In application to direct specimens, the possibility of false-negative results needs to be considered.

A review of peer-assisted learning to deliver interprofessional supplementary image interpretation skills.

PubMed

Bain, P; Wareing, A; Henderson, I

2017-09-01

Peer-assisted learning provides a means through which individuals can learn from one another through a reciprocal process. Radiographic image interpretation skills are fundamental to both diagnostic radiography students and medical students due to their shared role in preliminary evaluation of conventional radiographic images. Medical students on graduation, may not be well prepared to carry out image interpretation, since evidence suggests that they perform less well than radiographers in e.g. Accident and Emergency situations. A review of literature was conducted exploring the application of peer-assisted learning within diagnostic radiography and health education more widely as well as the practice of initial image interpretation. An extensive and systematic search strategy was developed which provided a range of material related to the areas. An overview was obtained of the effectiveness of peer-assisted learning and the issues associated with development of image interpretation skills and a degree of discrepancy was identified between the two cohorts regarding their interpretative competence and confidence. This inconsistency may create an opportunity to apply peer-assisted learning, better preparing both disciplines for the practical application of image interpretation skills. The review identified the lack of a substantial evidence base relating to peer-assisted learning in radiography. Peer-assisted learning is not widely embraced in an interprofessional context. Multiple positive factors of such an intervention are identified which outweigh perceived negative issues. Student teacher and learner may benefit as should the clinical service from enhanced practitioner performance. The findings justify further research to develop the evidence base. Copyright © 2017 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

Statistics 101 for Radiologists.

PubMed

Anvari, Arash; Halpern, Elkan F; Samir, Anthony E

2015-10-01

Diagnostic tests have wide clinical applications, including screening, diagnosis, measuring treatment effect, and determining prognosis. Interpreting diagnostic test results requires an understanding of key statistical concepts used to evaluate test efficacy. This review explains descriptive statistics and discusses probability, including mutually exclusive and independent events and conditional probability. In the inferential statistics section, a statistical perspective on study design is provided, together with an explanation of how to select appropriate statistical tests. Key concepts in recruiting study samples are discussed, including representativeness and random sampling. Variable types are defined, including predictor, outcome, and covariate variables, and the relationship of these variables to one another. In the hypothesis testing section, we explain how to determine if observed differences between groups are likely to be due to chance. We explain type I and II errors, statistical significance, and study power, followed by an explanation of effect sizes and how confidence intervals can be used to generalize observed effect sizes to the larger population. Statistical tests are explained in four categories: t tests and analysis of variance, proportion analysis tests, nonparametric tests, and regression techniques. We discuss sensitivity, specificity, accuracy, receiver operating characteristic analysis, and likelihood ratios. Measures of reliability and agreement, including κ statistics, intraclass correlation coefficients, and Bland-Altman graphs and analysis, are introduced. © RSNA, 2015.

[Parametrial infiltration of cervix carcinoma: diagnostic value of contrast-enhanced fat-suppressed T1-weighted SE sequences at 1.5 tesla].

PubMed

Scheidler, J; Heuck, A; Wencke, K; Kimmig, R; Müller-Lisse, U; Reiser, M

1997-04-01

To determine whether contrast-enhanced and fat-suppressed sequences contribute to the MR imaging diagnosis of parametrial invasion. 21 patients with carcinoma of the cervix were prospectively examined with a phased-array coil and a 1.5T MR-scanner using the following sequences: transverse T2-weighted turbo spin echo (T2-TSE), T1-weighted spin echo (T1-SE) and fat suppressed T1-weighted SE sequences before and after Gd-DTPA. The sequences were evaluated separately for the presence of parametrial invasion. Image quality and diagnostic confidence were classified on a scale of 0-10 (nondiagnostic-excellent). Findings were compared to the results of the pathohistological examination. Sensitivity, specificity and diagnostic accuracy were highest for T2-TSE sequences (100%, 79% and 86%, respectively). Contrast-enhanced T1-SE sequences with fat-suppression (71%, 79%, and 76%) showed no improvement compared to T2-TSE. Unenhanced fat-suppressed T1-SE (100%, 30%, and 56%) and unenhanced T1-SE (100%, 7%, and 38%) as well as contrast-enhanced T1-SE (86%, 20%, and 47%) were significantly worse than T2-TSE. With similar image quality (p < 0.05) diagnostic confidence was higher on T2-TSE than on any of the other sequences (p < 0.001). Considering the cost-effectiveness of the examination, for the MR diagnosis of parametrial invasion the use of fat-suppressed contrast-enhanced sequences can be abandoned in favour of T2-weighted TSE sequences.

Insertable cardiac monitors in the diagnosis of syncope and the detection of atrial fibrillation: A systematic review and meta-analysis.

PubMed

Burkowitz, Jörg; Merzenich, Carina; Grassme, Kathrin; Brüggenjürgen, Bernd

2016-08-01

Insertable or implantable cardiac monitors (ICMs) continuously monitor the heart rhythm and record irregularities over 3 years, enabling the diagnosis of infrequent rhythm abnormalities associated with syncope and stroke. The enhanced recognition capabilities of recent ICM models are able to accurately detect atrial fibrillation (AF) and have led to new applications of ICMs for the detection and monitoring of AF. Based on a systematic literature search, two indications were identified for ICMs for which considerable evidence, including randomized studies, exists: diagnosing the underlying cardiac cause of unexplained recurrent syncope and detecting AF in patients after cryptogenic stroke (CS). Three randomized controlled trials (RCTs) were identified that compared the effectiveness of ICMs in diagnosing patients with unexplained syncope (n = 556) to standard of care. A meta-analysis was conducted in order to generate an overall effect size and confidence interval of the diagnostic yield of ICMs versus conventional monitoring. In the indication CS, one RCT and five observational studies were included in order to assess the performance of ICMs in diagnosing patients with AF (n = 1129). Based on these studies, there is strong evidence that ICMs provide a higher diagnostic yield for detecting arrhythmias in patients with unexplained syncope and for detection of AF in patients after CS compared to conventional monitoring. Prolonged monitoring with ICMs is an effective tool for diagnosing the underlying cardiac cause of unexplained syncope and for detecting AF in patients with CS. In all RCTs, ICMs have a superior diagnostic yield compared to conventional monitoring. © The European Society of Cardiology 2016.

Experimental plasma research project summaries

NASA Astrophysics Data System (ADS)

1992-06-01

This is the latest in a series of Project Summary books that date back to 1976. It is the first after a hiatus of several years. They are published to provide a short description of each project supported by the Experimental Plasma Research Branch of the Division of Applied Plasma Physics in the Office of Fusion Energy. The Experimental Plasma Research Branch seeks to provide a broad range of experimental data, physics understanding, and new experimental techniques that contribute to operation, interpretation, and improvement of high temperature plasma as a source of fusion energy. In pursuit of these objectives, the branch supports research at universities, DOE laboratories, other federal laboratories, and industry. About 70 percent of the funds expended are spent at universities and a significant function of this program is the training of students in fusion physics. The branch supports small- and medium-scale experimental studies directly related to specific critical plasma issues of the magnetic fusion program. Plasma physics experiments are conducted on transport of particles and energy within plasma. Additionally, innovative approaches for operating, controlling, and heating plasma are evaluated for application to the larger confinement devices of the magnetic fusion program. New diagnostic approaches to measuring the properties of high temperature plasmas are developed to the point where they can be applied with confidence on the large-scale confinement experiments. Atomic data necessary for impurity control, interpretation of diagnostic data, development of heating devices, and analysis of cooling by impurity ion radiation are obtained. The project summaries are grouped into the three categories of plasma physics, diagnostic development, and atomic physics.

The 2016 Academic Emergency Medicine Consensus Conference, "Shared Decision Making in the Emergency Department: Development of a Policy-relevant Patient-centered Research Agenda" Diagnostic Testing Breakout Session Report.

PubMed

Barrett, Tyler W; Rising, Kristin L; Bellolio, M Fernanda; Hall, M Kennedy; Brody, Aaron; Dodd, Kenneth W; Grieser, Mira; Levy, Phillip D; Raja, Ali S; Self, Wesley H; Weingarten, Gail; Hess, Erik P; Hollander, Judd E

2016-12-01

Diagnostic testing is an integral component of patient evaluation in the emergency department (ED). Emergency clinicians frequently use diagnostic testing to more confidently exclude "worst-case" diagnoses rather than to determine the most likely etiology for a presenting complaint. Increased utilization of diagnostic testing has not been associated with reductions in disease-related mortality but has led to increased overall healthcare costs and other unintended consequences (e.g., incidental findings requiring further workup, unnecessary exposure to ionizing radiation or potentially nephrotoxic contrast). Shared decision making (SDM) presents an opportunity for clinicians to discuss the benefits and harms associated with diagnostic testing with patients to more closely tailor testing to patient risk. This article introduces the challenges and opportunities associated with incorporating SDM into emergency care by summarizing the conclusions of the diagnostic testing group at the 2016 Academic Emergency Medicine Consensus Conference on SDM. Three primary domains emerged: 1) characteristics of a condition or test appropriate for SDM, 2) critical elements of and potential barriers to SDM discussions on diagnostic testing, and 3) financial aspects of SDM applied to diagnostic testing. The most critical research questions to improve engagement of patients in their acute care diagnostic decisions were determined by consensus. © 2016 by the Society for Academic Emergency Medicine.

Photoplethysmography using a smartphone application for assessment of ulnar artery patency: a randomized clinical trial

PubMed Central

Di Santo, Pietro; Harnett, David T.; Simard, Trevor; Ramirez, F. Daniel; Pourdjabbar, Ali; Yousef, Altayyeb; Moreland, Robert; Bernick, Jordan; Wells, George; Dick, Alexander; Le May, Michel; Labinaz, Marino; So, Derek; Motazedian, Pouya; Jung, Richard G.; Chandrasekhar, Jaya; Mehran, Roxana; Chong, Aun-Yeong

2018-01-01

BACKGROUND: Radial artery access is commonly performed for coronary angiography and invasive hemodynamic monitoring. Despite limitations in diagnostic accuracy, the modified Allen test (manual occlusion of radial and ulnar arteries followed by release of the latter and assessment of palmar blush) is used routinely to evaluate the collateral circulation to the hand and, therefore, to determine patient eligibility for radial artery access. We sought to evaluate whether a smartphone application may provide a superior alternative to the modified Allen test. METHODS: We compared the modified Allen test with a smartphone heart rate–monitoring application (photoplethysmography readings detected using a smartphone camera lens placed on the patient’s index finger) in patients undergoing a planned cardiac catheterization. Test order was randomly assigned in a 1:1 fashion. All patients then underwent conventional plethysmography of the index finger, followed by Doppler ultrasonography of the radial and ulnar arteries (the diagnostic standard). The primary outcome was diagnostic accuracy of the heart rate–monitoring application. RESULTS: Among 438 patients who were included in the study, we found that the heart rate–monitoring application had a superior diagnostic accuracy compared with the modified Allen test (91.8% v. 81.7%, p = 0.002), attributable to its greater specificity (93.0% v. 82.8%, p = 0.001). We also found that this application had greater diagnostic accuracy for assessment of radial or ulnar artery patency in the ipsilateral and contralateral wrist (94.0% v. 84.0%, p < 0.001). INTERPRETATION: A smartphone application used at the bedside was diagnostically superior to traditional physical examination for confirming ulnar patency before radial artery access. This study highlights the potential for smartphone-based diagnostics to aid in clinical decision-making at the patient’s bedside. Trial registration: Clinicaltrials.gov, no. NCT02519491. PMID:29615421

Photoplethysmography using a smartphone application for assessment of ulnar artery patency: a randomized clinical trial.

PubMed

Di Santo, Pietro; Harnett, David T; Simard, Trevor; Ramirez, F Daniel; Pourdjabbar, Ali; Yousef, Altayyeb; Moreland, Robert; Bernick, Jordan; Wells, George; Dick, Alexander; Le May, Michel; Labinaz, Marino; So, Derek; Motazedian, Pouya; Jung, Richard G; Chandrasekhar, Jaya; Mehran, Roxana; Chong, Aun-Yeong; Hibbert, Benjamin

2018-04-03

Radial artery access is commonly performed for coronary angiography and invasive hemodynamic monitoring. Despite limitations in diagnostic accuracy, the modified Allen test (manual occlusion of radial and ulnar arteries followed by release of the latter and assessment of palmar blush) is used routinely to evaluate the collateral circulation to the hand and, therefore, to determine patient eligibility for radial artery access. We sought to evaluate whether a smartphone application may provide a superior alternative to the modified Allen test. We compared the modified Allen test with a smartphone heart rate-monitoring application (photoplethysmography readings detected using a smartphone camera lens placed on the patient's index finger) in patients undergoing a planned cardiac catheterization. Test order was randomly assigned in a 1:1 fashion. All patients then underwent conventional plethysmography of the index finger, followed by Doppler ultrasonography of the radial and ulnar arteries (the diagnostic standard). The primary outcome was diagnostic accuracy of the heart rate-monitoring application. Among 438 patients who were included in the study, we found that the heart rate-monitoring application had a superior diagnostic accuracy compared with the modified Allen test (91.8% v. 81.7%, p = 0.002), attributable to its greater specificity (93.0% v. 82.8%, p = 0.001). We also found that this application had greater diagnostic accuracy for assessment of radial or ulnar artery patency in the ipsilateral and contralateral wrist (94.0% v. 84.0%, p < 0.001). A smartphone application used at the bedside was diagnostically superior to traditional physical examination for confirming ulnar patency before radial artery access. This study highlights the potential for smartphone-based diagnostics to aid in clinical decision-making at the patient's bedside. Trial registration: Clinicaltrials.gov, no. NCT02519491. © 2018 Joule Inc. or its licensors.

Added Value of Coronal Reformations for Duty Radiologists and for Referring Physicians or Surgeons in the CT Diagnosis of Acute Appendicitis

PubMed Central

Lee, Kyoung Ho; Hahn, Seokyung; Lee, Kyung Won; Lee, Hak Jong; Kim, Tae Jung; Kang, Sung-Bum; Shin, Joong Ho; Park, Byung Joo

2006-01-01

Objective To assess the added value of coronal reformation for radiologists and for referring physicians or surgeons in the CT diagnosis of acute appendicitis. Materials and Methods Contrast-enhanced CT was performed using 16-detector-row scanners in 110 patients, 46 of whom had appendicitis. Transverse (5-mm thickness, 4-mm increment), coronal (5-mm thickness, 4-mm increment), and combined transverse and coronal sections were interpreted by four radiologists, two surgeons and two emergency physicians. The area under the receiver operating characteristic curve (Az value), sensitivity, specificity (McNemar test), diagnostic confidence and appendiceal visualization (Wilcoxon signed rank test) were compared. Results For radiologists, the additional coronal sections tended to increase the Az value (0.972 vs. 0.986, p = 0.076) and pooled sensitivity (92% [95% CI: 88, 96] vs. 96% [93, 99]), and enhanced appendiceal visualization in true-positive cases (p = 0.031). For non-radiologists, no such enhancement was observed, and the confidence for excluding acute appendicitis declined (p = 0.013). Coronal sections alone were inferior to transverse sections for diagnostic confidence as well as appendiceal visualization for each reader group studied (p < 0.05). Conclusion The added value of coronal reformation is more apparent for radiologists compared to referring physicians or surgeons in the CT diagnosis of acute appendicitis. PMID:16799269

Towards increase of diagnostic efficacy in gynecologic OCT

NASA Astrophysics Data System (ADS)

Kirillin, Mikhail; Panteleeva, Olga; Eliseeva, Darya; Kachalina, Olga; Sergeeva, Ekaterina; Dubasova, Lyubov; Agrba, Pavel; Mikailova, Gyular; Prudnikov, Maxim; Shakhova, Natalia

2013-06-01

Gynecologic applications of optical coherence tomography (OCT) are usually performed in combination with routine diagnostic procedures: laparoscopy and colposcopy. In combination with laparoscopy OCT is employed for inspection of fallopian tubes in cases of unrecognized infertility while in colposcopy it is used to identify cervix pathologies including cancer. In this paper we discuss methods for increasing diagnostic efficacy of OCT application in these procedures. For OCT-laparoscopy we demonstrate independent criteria for pathology recognition which allow to increase accuracy of diagnostics. For OCT-colposcopy we report on application of device for controlled compression allowing to sense the elasticity of the inspected cervix area and distinguish between neoplasia and inflammatory processes.

Research at ITER towards DEMO: Specific reactor diagnostic studies to be carried out on ITER

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

Krasilnikov, A. V.; Kaschuck, Y. A.; Vershkov, V. A.

2014-08-21

In ITER diagnostics will operate in the very hard radiation environment of fusion reactor. Extensive technology studies are carried out during development of the ITER diagnostics and procedures of their calibration and remote handling. Results of these studies and practical application of the developed diagnostics on ITER will provide the direct input to DEMO diagnostic development. The list of DEMO measurement requirements and diagnostics will be determined during ITER experiments on the bases of ITER plasma physics results and success of particular diagnostic application in reactor-like ITER plasma. Majority of ITER diagnostic already passed the conceptual design phase and representmore » the state of the art in fusion plasma diagnostic development. The number of related to DEMO results of ITER diagnostic studies such as design and prototype manufacture of: neutron and γ–ray diagnostics, neutral particle analyzers, optical spectroscopy including first mirror protection and cleaning technics, reflectometry, refractometry, tritium retention measurements etc. are discussed.« less

Research at ITER towards DEMO: Specific reactor diagnostic studies to be carried out on ITER

NASA Astrophysics Data System (ADS)

Krasilnikov, A. V.; Kaschuck, Y. A.; Vershkov, V. A.; Petrov, A. A.; Petrov, V. G.; Tugarinov, S. N.

2014-08-01

In ITER diagnostics will operate in the very hard radiation environment of fusion reactor. Extensive technology studies are carried out during development of the ITER diagnostics and procedures of their calibration and remote handling. Results of these studies and practical application of the developed diagnostics on ITER will provide the direct input to DEMO diagnostic development. The list of DEMO measurement requirements and diagnostics will be determined during ITER experiments on the bases of ITER plasma physics results and success of particular diagnostic application in reactor-like ITER plasma. Majority of ITER diagnostic already passed the conceptual design phase and represent the state of the art in fusion plasma diagnostic development. The number of related to DEMO results of ITER diagnostic studies such as design and prototype manufacture of: neutron and γ-ray diagnostics, neutral particle analyzers, optical spectroscopy including first mirror protection and cleaning technics, reflectometry, refractometry, tritium retention measurements etc. are discussed.

First-year medical students use of ultrasound or physical examination to diagnose hepatomegaly and ascites: a randomized controlled trial.

PubMed

Arora, Samantha; Cheung, Angela C; Tarique, Usman; Agarwal, Arnav; Firdouse, Mohammed; Ailon, Jonathan

2017-09-01

To compare point-of-care ultrasound and physical examination (PEx), each performed by first-year medical students after brief teaching, for assessing ascites and hepatomegaly. Ultrasound and PEx were compared on: (1) reliability, validity and performance, (2) diagnostic confidence, ease of use, utility, and applicability. A single-center, randomized controlled trial was performed at a tertiary centre. First-year medical students were randomized to use ultrasound or PEx to assess for ascites and hepatomegaly. Cohen's kappa and interclass coefficient (ICC) were used to measure interrater reliability between trainee assessments and the reference standard (a same day ultrasound by a radiologist). Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were compared. A ten-point Likert scale was used to assess trainee diagnostic confidence and perceptions of utility. There were no significant differences in interobserver reliability, sensitivity, specificity, accuracy, PPV, or NPV between the ultrasound and PEx groups. However, students in the ultrasound group provided higher scores for perceived utility (ascites 8.38 ± 1.35 vs 7.08 ± 1.86, p  = 0.008; hepatomegaly 7.68 ± 1.52 vs 5.36 ± 2.48, p  < 0.001) and likelihood of adoption (ascites 8.67 ± 1.61 vs 7.46 ± 1.79, p  = 0.02; hepatomegaly 8.12 ± 1.90 vs 5.92 ± 2.32, p  = 0.001). When performed by first-year medical students, the validity and reliability of ultrasound is comparable to PEx, but with greater perceived utility and likelihood of adoption. With similarly brief instruction, point-of-care ultrasonography can be as effectively learned and performed as PEx, with a high degree of interest from trainees.

TU-AB-202-03: Prediction of PET Transfer Uncertainty by DIR Error Estimating Software, AUTODIRECT

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

Kim, H; Chen, J; Phillips, J

2016-06-15

Purpose: Deformable image registration (DIR) is a powerful tool, but DIR errors can adversely affect its clinical applications. To estimate voxel-specific DIR uncertainty, a software tool, called AUTODIRECT (automated DIR evaluation of confidence tool), has been developed and validated. This work tests the ability of this software to predict uncertainty for the transfer of standard uptake values (SUV) from positron-emission tomography (PET) with DIR. Methods: Virtual phantoms are used for this study. Each phantom has a planning computed tomography (CT) image and a diagnostic PET-CT image set. A deformation was digitally applied to the diagnostic CT to create the planningmore » CT image and establish a known deformation between the images. One lung and three rectum patient datasets were employed to create the virtual phantoms. Both of these sites have difficult deformation scenarios associated with them, which can affect DIR accuracy (lung tissue sliding and changes in rectal filling). The virtual phantoms were created to simulate these scenarios by introducing discontinuities in the deformation field at the lung rectum border. The DIR algorithm from Plastimatch software was applied to these phantoms. The SUV mapping errors from the DIR were then compared to that predicted by AUTODIRECT. Results: The SUV error distributions closely followed the AUTODIRECT predicted error distribution for the 4 test cases. The minimum and maximum PET SUVs were produced from AUTODIRECT at 95% confidence interval before applying gradient-based SUV segmentation for each of these volumes. Notably, 93.5% of the target volume warped by the true deformation was included within the AUTODIRECT-predicted maximum SUV volume after the segmentation, while 78.9% of the target volume was within the target volume warped by Plastimatch. Conclusion: The AUTODIRECT framework is able to predict PET transfer uncertainty caused by DIR, which enables an understanding of the associated target volume uncertainty.« less

Quality systems in veterinary diagnostics laboratories.

PubMed

de Branco, Freitas Maia L M

2007-01-01

Quality assurance of services provided by veterinary diagnostics laboratories is a fundamental element promoted by international animal health organizations to establish trust, confidence and transparency needed for the trade of animals and their products at domestic and international levels. It requires, among other things, trained personnel, consistent and rigorous methodology, choice of suitable methods as well as appropriate calibration and traceability procedures. An important part of laboratory quality management is addressed by ISO/IEC 17025, which aims to facilitate cooperation among laboratories and their associated parties by assuring the generation of credible and consistent information derived from analytical results. Currently, according to OIE recommendation, veterinary diagnostics laboratories are only subject to voluntary compliance with standard ISO/IEC 17025; however, it is proposed here that OIE reference laboratories and collaboration centres strongly consider its adoption.

Repeated significance tests of linear combinations of sensitivity and specificity of a diagnostic biomarker

PubMed Central

Wu, Mixia; Shu, Yu; Li, Zhaohai; Liu, Aiyi

2016-01-01

A sequential design is proposed to test whether the accuracy of a binary diagnostic biomarker meets the minimal level of acceptance. The accuracy of a binary diagnostic biomarker is a linear combination of the marker’s sensitivity and specificity. The objective of the sequential method is to minimize the maximum expected sample size under the null hypothesis that the marker’s accuracy is below the minimal level of acceptance. The exact results of two-stage designs based on Youden’s index and efficiency indicate that the maximum expected sample sizes are smaller than the sample sizes of the fixed designs. Exact methods are also developed for estimation, confidence interval and p-value concerning the proposed accuracy index upon termination of the sequential testing. PMID:26947768

Proximal pulmonary vein stenosis detection in pediatric patients: value of multiplanar and 3-D VR imaging evaluation.

PubMed

Lee, Edward Y; Jenkins, Kathy J; Muneeb, Muhammad; Marshall, Audrey C; Tracy, Donald A; Zurakowski, David; Boiselle, Phillip M

2013-08-01

One of the important benefits of using multidetector computed tomography (MDCT) is its capability to generate high-quality two-dimensional (2-D) multiplanar (MPR) and three-dimensional (3-D) images from volumetric and isotropic axial CT data. However, to the best of our knowledge, no results have been published on the potential diagnostic role of multiplanar and 3-D volume-rendered (VR) images in detecting pulmonary vein stenosis, a condition in which MDCT has recently assumed a role as the initial noninvasive imaging modality of choice. The purpose of this study was to compare diagnostic accuracy and interpretation time of axial, multiplanar and 3-D VR images for detection of proximal pulmonary vein stenosis in children, and to assess the potential added diagnostic value of multiplanar and 3-D VR images. We used our hospital information system to identify all consecutive children (< 18 years of age) with proximal pulmonary vein stenosis who had both a thoracic MDCT angiography study and a catheter-based conventional angiography within 2 months from June 2005 to February 2012. Two experienced pediatric radiologists independently reviewed each MDCT study for the presence of proximal pulmonary vein stenosis defined as ≥ 50% of luminal narrowing on axial, multiplanar and 3-D VR images. Final diagnosis was confirmed by angiographic findings. Diagnostic accuracy was compared using the z-test. Confidence level of diagnosis (scale 1-5, 5 = highest), perceived added diagnostic value (scale 1-5, 5 = highest), and interpretation time of multiplanar or 3-D VR images were compared using paired t-tests. Interobserver agreement was measured using the chance-corrected kappa coefficient. The final study population consisted of 28 children (15 boys and 13 girls; mean age: 5.2 months). Diagnostic accuracy based on 116 individual pulmonary veins for detection of proximal pulmonary vein stenosis was 72.4% (84 of 116) for axial MDCT images, 77.5% (90 of 116 cases) for multiplanar MDCT images, and 93% (108 of 116 cases) for 3-D VR images with significantly higher accuracy with 3-D VR compared to axial (z = 4.17, P < 0.001) and multiplanar (z = 3.34, P < 0.001) images. Confidence levels for detection of proximal pulmonary vein stenosis were significantly higher with 3-D VR images (mean level: 4.6) compared to axial MDCT images (mean level: 1.7) and multiplanar MDCT images (mean level: 2.0) (paired t-tests, P < 0.001). Thus, 3-D VR images (mean added diagnostic value: 4.7) were found to provide added diagnostic value for detecting proximal pulmonary vein stenosis (paired t-test, P < 0.001); however, multiplanar MDCT images did not provide added value (paired t-test, P = 0.89). Interpretation time was significantly longer and interobserver agreement was higher when using 3-D VR images than using axial MDCT images or MPR MDCT images for diagnosing proximal pulmonary vein stenosis (paired t-tests, P < 0.001). Use of 3-D VR images in the diagnosis of proximal pulmonary vein stenosis in children significantly increases accuracy, confidence level, added diagnostic value and interobserver agreement. Thus, the routine use of this technique should be encouraged despite its increased interpretation time.

Clinical Factors and Disease Course Related to Diagnostic Delay in Korean Crohn's Disease Patients: Results from the CONNECT Study.

PubMed

Moon, Chang Mo; Jung, Sung-Ae; Kim, Seong-Eun; Song, Hyun Joo; Jung, Yunho; Ye, Byong Duk; Cheon, Jae Hee; Kim, You Sun; Kim, Young-Ho; Kim, Joo Sung; Han, Dong Soo

2015-01-01

Diagnostic delay frequently occurs in Crohn's disease (CD) patients because of diagnostic limitations. However, diagnostic delay and its related factors remain poorly defined. Therefore, we aimed to identify the predictors associated with diagnostic delay and to evaluate the impact of diagnostic delay on clinical course in a Korean CD patient cohort. We performed a multicenter retrospective analysis of 1,047 CD patients registered in the Crohn's Disease Clinical Network and Cohort study in Korea. The mean interval of diagnostic delay was 16.0 ± 33.1 months. Multivariate analysis showed that older age at diagnosis (≥40 years) (p = 0.014), concomitant upper gastrointestinal (UGI) disease (p = 0.012) and penetrating disease behavior at diagnosis (p = 0.001) were positively associated with long diagnostic delay (≥18 months). During the longitudinal follow-up, long diagnostic delay was independently predictive of further development of intestinal stenosis (hazard ratio [HR], 1.43; 95% confidence interval [CI], 1.07-1.93; p = 0.017), internal fistulas (HR, 1.62; 95% CI, 1.12-2.33; p = 0.011), and perianal fistulas (HR, 1.38; 95% CI, 1.06-1.80; p = 0.016). However, as for the risk of abscess formation, bowel perforation, and CD-related abdominal surgery, no significant association with diagnostic delay was observed. Older age at diagnosis, UGI involvement, and penetrating behavior are associated with long diagnostic delay in Korean CD patients. Moreover, diagnostic delay is associated with an increased risk of CD-related complications such as intestinal stenosis, internal fistulas, and perianal fistulas.

Pediatric chest HRCT using the iDose4 Hybrid Iterative Reconstruction Algorithm: Which iDose level to choose?

NASA Astrophysics Data System (ADS)

Smarda, M.; Alexopoulou, E.; Mazioti, A.; Kordolaimi, S.; Ploussi, A.; Priftis, K.; Efstathopoulos, E.

2015-09-01

Purpose of the study is to determine the appropriate iterative reconstruction (IR) algorithm level that combines image quality and diagnostic confidence, for pediatric patients undergoing high-resolution computed tomography (HRCT). During the last 2 years, a total number of 20 children up to 10 years old with a clinical presentation of chronic bronchitis underwent HRCT in our department's 64-detector row CT scanner using the iDose IR algorithm, with almost similar image settings (80kVp, 40-50 mAs). CT images were reconstructed with all iDose levels (level 1 to 7) as well as with filtered-back projection (FBP) algorithm. Subjective image quality was evaluated by 2 experienced radiologists in terms of image noise, sharpness, contrast and diagnostic acceptability using a 5-point scale (1=excellent image, 5=non-acceptable image). Artifacts existance was also pointed out. All mean scores from both radiologists corresponded to satisfactory image quality (score ≤3), even with the FBP algorithm use. Almost excellent (score <2) overall image quality was achieved with iDose levels 5 to 7, but oversmoothing artifacts appearing with iDose levels 6 and 7 affected the diagnostic confidence. In conclusion, the use of iDose level 5 enables almost excellent image quality without considerable artifacts affecting the diagnosis. Further evaluation is needed in order to draw more precise conclusions.

X-ray dark-field radiography facilitates the diagnosis of pulmonary fibrosis in a mouse model.

PubMed

Hellbach, Katharina; Yaroshenko, Andre; Willer, Konstantin; Conlon, Thomas M; Braunagel, Margarita B; Auweter, Sigrid; Yildirim, Ali Ö; Eickelberg, Oliver; Pfeiffer, Franz; Reiser, Maximilian F; Meinel, Felix G

2017-03-23

The aim of this study was to evaluate whether diagnosing pulmonary fibrosis with projection radiography can be improved by using X-ray dark-field radiograms. Pulmonary X-ray transmission and dark-field images of C57Bl/6N mice, either treated with bleomycin to induce pulmonary fibrosis or PBS to serve as controls, were acquired with a prototype grating-based small-animal scanner. Two blinded readers, both experienced radiologists and familiar with dark-field imaging, had to assess dark-field and transmission images for the absence or presence of fibrosis. Furthermore readers were asked to grade their stage of diagnostic confidence. Histological evaluation of the lungs served as the standard of reference in this study. Both readers showed a notably higher diagnostic confidence when analyzing the dark-field radiographs (p < 0.001). Diagnostic accuracy improved significantly when evaluating the lungs in dark-field images alone (p = 0.02) or in combination with transmission images (p = 0.01) compared to sole analysis of absorption images. Interreader agreement improved from good when assessing only transmission images to excellent when analyzing dark-field images alone or in combination with transmission images. Adding dark-field images to conventional transmission images in a murine model of pulmonary fibrosis leads to an improved diagnosis of this disease on chest radiographs.

Do we need gadolinium-based contrast medium for brain magnetic resonance imaging in children?

PubMed

Dünger, Dennis; Krause, Matthias; Gräfe, Daniel; Merkenschlager, Andreas; Roth, Christian; Sorge, Ina

2018-06-01

Brain imaging is the most common examination in pediatric magnetic resonance imaging (MRI), often combined with the use of a gadolinium-based contrast medium. The application of gadolinium-based contrast medium poses some risk. There is limited evidence of the benefits of contrast medium in pediatric brain imaging. To assess the diagnostic gain of contrast-enhanced sequences in brain MRI when the unenhanced sequences are normal. We retrospectively assessed 6,683 brain MR examinations using contrast medium in children younger than 16 years in the pediatric radiology department of the University Hospital Leipzig to determine whether contrast-enhanced sequences delivered additional, clinically relevant information to pre-contrast sequences. All examinations were executed using a 1.5-T or a 3-T system. In 8 of 3,003 (95% confidence interval 0.12-0.52%) unenhanced normal brain examinations, a relevant additional finding was detected when contrast medium was administered. Contrast enhancement led to a change in diagnosis in only one of these cases. Children with a normal pre-contrast brain MRI rarely benefit from contrast medium application. Comparing these results to the risks and disadvantages of a routine gadolinium application, there is substantiated numerical evidence for avoiding routine administration of gadolinium in a pre-contrast normal MRI examination.

Etiological classifications of transient ischemic attacks: subtype classification by TOAST, CCS and ASCO--a pilot study.

PubMed

Amort, Margareth; Fluri, Felix; Weisskopf, Florian; Gensicke, Henrik; Bonati, Leo H; Lyrer, Philippe A; Engelter, Stefan T

2012-01-01

In patients with transient ischemic attacks (TIA), etiological classification systems are not well studied. The Trial of ORG 10172 in Acute Stroke Treatment (TOAST), the Causative Classification System (CCS), and the Atherosclerosis Small Vessel Disease Cardiac Source Other Cause (ASCO) classification may be useful to determine the underlying etiology. We aimed at testing the feasibility of each of the 3 systems. Furthermore, we studied and compared their prognostic usefulness. In a single-center TIA registry prospectively ascertained over 2 years, we applied 3 etiological classification systems. We compared the distribution of underlying etiologies, the rates of patients with determined versus undetermined etiology, and studied whether etiological subtyping distinguished TIA patients with versus without subsequent stroke or TIA within 3 months. The 3 systems were applicable in all 248 patients. A determined etiology with the highest level of causality was assigned similarly often with TOAST (35.9%), CCS (34.3%), and ASCO (38.7%). However, the frequency of undetermined causes differed significantly between the classification systems and was lowest for ASCO (TOAST: 46.4%; CCS: 37.5%; ASCO: 18.5%; p < 0.001). In TOAST, CCS, and ASCO, cardioembolism (19.4/14.5/18.5%) was the most common etiology, followed by atherosclerosis (11.7/12.9/14.5%). At 3 months, 33 patients (13.3%, 95% confidence interval 9.3-18.2%) had recurrent cerebral ischemic events. These were strokes in 13 patients (5.2%; 95% confidence interval 2.8-8.8%) and TIAs in 20 patients (8.1%, 95% confidence interval 5.0-12.2%). Patients with a determined etiology (high level of causality) had higher rates of subsequent strokes than those without a determined etiology [TOAST: 6.7% (95% confidence interval 2.5-14.1%) vs. 4.4% (95% confidence interval 1.8-8.9%); CSS: 9.3% (95% confidence interval 4.1-17.5%) vs. 3.1% (95% confidence interval 1.0-7.1%); ASCO: 9.4% (95% confidence interval 4.4-17.1%) vs. 2.6% (95% confidence interval 0.7-6.6%)]. However, this difference was only significant in the ASCO classification (p = 0.036). Using ASCO, there was neither an increase in risk of subsequent stroke among patients with incomplete diagnostic workup (at least one subtype scored 9) compared with patients with adequate workup (no subtype scored 9), nor among patients with multiple causes compared with patients with a single cause. In TIA patients, all etiological classification systems provided a similar distribution of underlying etiologies. The increase in stroke risk in TIA patients with determined versus undetermined etiology was most evident using the ASCO classification. Copyright © 2012 S. Karger AG, Basel.

New possibilities of complex "Thermodyn" application for contactless remote diagnostics in medical practice

NASA Astrophysics Data System (ADS)

Belov, M. Ye.; Shayko-Shaykovskiy, O. G.; Makhrova, Ye. G.; Kramar, V. M.; Oleksuik, I. S.

2018-01-01

We represent here the theoretical justifications, block scheme and experimental sample of a new automated complex "Thermodyn" for remote contactless diagnostics of inflammatory processes of the surfaces and in subcutaneous areas of human body. Also we described here the methods and results of diagnostic measurements, and results of practical applications of this complex.

Bayes' theorem application in the measure information diagnostic value assessment

NASA Astrophysics Data System (ADS)

Orzechowski, Piotr D.; Makal, Jaroslaw; Nazarkiewicz, Andrzej

2006-03-01

The paper presents Bayesian method application in the measure information diagnostic value assessment that is used in the computer-aided diagnosis system. The computer system described here has been created basing on the Bayesian Network and is used in Benign Prostatic Hyperplasia (BPH) diagnosis. The graphic diagnostic model enables to juxtapose experts' knowledge with data.

[Advances of Molecular Diagnostic Techniques Application in Clinical Diagnosis.

PubMed

Ying, Bin-Wu

2016-11-01

Over the past 20 years,clinical molecular diagnostic technology has made rapid development,and became the most promising field in clinical laboratory medicine.In particular,with the development of genomics,clinical molecular diagnostic methods will reveal the nature of clinical diseases in a deeper level,thus guiding the clinical diagnosis and treatments.Many molecular diagnostic projects have been routinely applied in clinical works.This paper reviews the advances on application of clinical diagnostic techniques in infectious disease,tumor and genetic disorders,including nucleic acid amplification,biochip,next-generation sequencing,and automation molecular system,and so on.

Meta-analysis for the comparison of two diagnostic tests to a common gold standard: A generalized linear mixed model approach.

PubMed

Hoyer, Annika; Kuss, Oliver

2018-05-01

Meta-analysis of diagnostic studies is still a rapidly developing area of biostatistical research. Especially, there is an increasing interest in methods to compare different diagnostic tests to a common gold standard. Restricting to the case of two diagnostic tests, in these meta-analyses the parameters of interest are the differences of sensitivities and specificities (with their corresponding confidence intervals) between the two diagnostic tests while accounting for the various associations across single studies and between the two tests. We propose statistical models with a quadrivariate response (where sensitivity of test 1, specificity of test 1, sensitivity of test 2, and specificity of test 2 are the four responses) as a sensible approach to this task. Using a quadrivariate generalized linear mixed model naturally generalizes the common standard bivariate model of meta-analysis for a single diagnostic test. If information on several thresholds of the tests is available, the quadrivariate model can be further generalized to yield a comparison of full receiver operating characteristic (ROC) curves. We illustrate our model by an example where two screening methods for the diagnosis of type 2 diabetes are compared.

Rayleigh Scattering Diagnostics Workshop

NASA Technical Reports Server (NTRS)

Seasholtz, Richard (Compiler)

1996-01-01

The Rayleigh Scattering Diagnostics Workshop was held July 25-26, 1995 at the NASA Lewis Research Center in Cleveland, Ohio. The purpose of the workshop was to foster timely exchange of information and expertise acquired by researchers and users of laser based Rayleigh scattering diagnostics for aerospace flow facilities and other applications. This Conference Publication includes the 12 technical presentations and transcriptions of the two panel discussions. The first panel was made up of 'users' of optical diagnostics, mainly in aerospace test facilities, and its purpose was to assess areas of potential applications of Rayleigh scattering diagnostics. The second panel was made up of active researchers in Rayleigh scattering diagnostics, and its purpose was to discuss the direction of future work.

An ROC-type measure of diagnostic accuracy when the gold standard is continuous-scale.

PubMed

Obuchowski, Nancy A

2006-02-15

ROC curves and summary measures of accuracy derived from them, such as the area under the ROC curve, have become the standard for describing and comparing the accuracy of diagnostic tests. Methods for estimating ROC curves rely on the existence of a gold standard which dichotomizes patients into disease present or absent. There are, however, many examples of diagnostic tests whose gold standards are not binary-scale, but rather continuous-scale. Unnatural dichotomization of these gold standards leads to bias and inconsistency in estimates of diagnostic accuracy. In this paper, we propose a non-parametric estimator of diagnostic test accuracy which does not require dichotomization of the gold standard. This estimator has an interpretation analogous to the area under the ROC curve. We propose a confidence interval for test accuracy and a statistical test for comparing accuracies of tests from paired designs. We compare the performance (i.e. CI coverage, type I error rate, power) of the proposed methods with several alternatives. An example is presented where the accuracies of two quick blood tests for measuring serum iron concentrations are estimated and compared.

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

Gelb, Bruce D; Tartaglia, Marco; Pennacchio, Len

Diagnostic and therapeutic applications for Noonan Syndrome are described. The diagnostic and therapeutic applications are based on certain mutations in a RAS-specific guanine nucleotide exchange factor gene SOS1 or its expression product. The diagnostic and therapeutic applications are also based on certain mutations in a serine/threonine protein kinase gene RAF1 or its expression product thereof. Also described are nucleotide sequences, amino acid sequences, probes, and primers related to RAF1 or SOS1, and variants thereof, as well as host cells expressing such variants.

ACCURACY OF PLASMA FREE METANEPHRINES IN THE DIAGNOSIS OF PHEOCHROMOCYTOMA AND PARAGANGLIOMA: A SYSTEMATIC REVIEW AND META-ANALYSIS.

PubMed

Chen, Yan; Xiao, Huangmeng; Zhou, Xieda; Huang, Xiaoyu; Li, Yanbing; Xiao, Haipeng; Cao, Xiaopei

2017-10-01

Various studies have validated plasma free metanephrines (MNs) as biomarkers for pheochromocytoma and paraganglioma (PPGL). This meta-analysis aimed to estimate the overall diagnostic accuracy of this biochemical test for PPGL. We searched the PubMed, the Cochrane Library, Web of Science, Embase, Scopus, OvidSP, and ProQuest Dissertations & Theses databases from January 1, 1995 to December 2, 2016 and selected studies written in English that assessed plasma free MNs in the diagnosis of PPGL. Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) was used to evaluate the quality of the included studies. We calculated pooled sensitivities, specificities, positive and negative likelihood ratios, diagnostic odds ratios (DORs) and areas under curve (AUCs) with their 95% confidence intervals (95% CIs). Heterogeneity was assessed by I 2 . To identify the source of heterogeneity, we evaluated the threshold effect and performed a meta-regression. Deeks' funnel plot was selected for investigating any potential publication bias. Although the combination of metanephrine (MN) and normetanephrine (NMN) carried lower specificity (0.94, 95% CI 0.90-0.97) than NMN (0.97, 95% CI 0.92-0.99), NMN was generally more accurate than individual tests, with the highest AUC (0.99, 95% CI 0.97-0.99), DOR (443.35, 95% CI 216.9-906.23), and pooled sensitivity (0.97, 95% CI 0.94-0.98) values. Threshold effect and meta-regression analyses showed that different cut-offs, blood sampling positions, study types and test methods contributed to heterogeneity. This meta-analysis suggested an effective value for combined plasma free MNs for the diagnosis of PPGL, but testing for MNs requires more standardization using tightly regulated studies. AUC = area under curve; CI = confidence interval; DOR = diagnostic odds ratio; EIA = enzyme immunoassay; LC-ECD = liquid chromatography-electrochemical detection; LC-MS/MS = liquid chromatography-tandem mass spectrometry; MN = metanephrine; NMN = normetaneprhine; PPGL = pheochromocytoma and paraganglioma; QUADAS-2 = Quality Assessment of Diagnostic Accuracy Studies 2.

Meta-Analyses of Diagnostic Accuracy in Imaging Journals: Analysis of Pooling Techniques and Their Effect on Summary Estimates of Diagnostic Accuracy.

PubMed

McGrath, Trevor A; McInnes, Matthew D F; Korevaar, Daniël A; Bossuyt, Patrick M M

2016-10-01

Purpose To determine whether authors of systematic reviews of diagnostic accuracy studies published in imaging journals used recommended methods for meta-analysis, and to evaluate the effect of traditional methods on summary estimates of sensitivity and specificity. Materials and Methods Medline was searched for published systematic reviews that included meta-analysis of test accuracy data limited to imaging journals published from January 2005 to May 2015. Two reviewers independently extracted study data and classified methods for meta-analysis as traditional (univariate fixed- or random-effects pooling or summary receiver operating characteristic curve) or recommended (bivariate model or hierarchic summary receiver operating characteristic curve). Use of methods was analyzed for variation with time, geographical location, subspecialty, and journal. Results from reviews in which study authors used traditional univariate pooling methods were recalculated with a bivariate model. Results Three hundred reviews met the inclusion criteria, and in 118 (39%) of those, authors used recommended meta-analysis methods. No change in the method used was observed with time (r = 0.54, P = .09); however, there was geographic (χ(2) = 15.7, P = .001), subspecialty (χ(2) = 46.7, P < .001), and journal (χ(2) = 27.6, P < .001) heterogeneity. Fifty-one univariate random-effects meta-analyses were reanalyzed with the bivariate model; the average change in the summary estimate was -1.4% (P < .001) for sensitivity and -2.5% (P < .001) for specificity. The average change in width of the confidence interval was 7.7% (P < .001) for sensitivity and 9.9% (P ≤ .001) for specificity. Conclusion Recommended methods for meta-analysis of diagnostic accuracy in imaging journals are used in a minority of reviews; this has not changed significantly with time. Traditional (univariate) methods allow overestimation of diagnostic accuracy and provide narrower confidence intervals than do recommended (bivariate) methods. (©) RSNA, 2016 Online supplemental material is available for this article.

Reliability and diagnostic validity of the slump knee bend neurodynamic test for upper/mid lumbar nerve root compression: a pilot study.

PubMed

Trainor, Kate; Pinnington, Mark A

2011-03-01

It has been proposed that neurodynamic examination can assist differential diagnosis of upper/mid lumbar nerve root compression; however, the diagnostic validity of many of these tests has yet to be established. This pilot study aimed to establish the diagnostic validity of the slump knee bend neurodynamic test for upper/mid lumbar nerve root compression in subjects with suspected lumbosacral radicular pain. Two independent examiners performed the slump knee bend test on subjects with radicular leg pain. Inter-tester reliability was calculated using the kappa coefficient. Slump knee bend test results were compared with magnetic resonance imaging findings, and diagnostic accuracy measures were calculated including sensitivity, specificity, predictive values and likelihood ratios. Orthopaedic spinal clinic, secondary care. Sixteen patients with radicular leg pain. All four subjects with mid lumbar nerve root compression on magnetic resonance imaging were correctly identified with the slump knee bend test; however, it was falsely positive in two individuals without the condition. Inter-tester reliability for the slump knee bend test using the kappa coefficient was 0.71 (95% confidence interval 0.33 to 1.0). Diagnostic validity calculations for the slump knee bend test (95% confidence intervals) were: sensitivity, 100% (40 to 100%); specificity, 83% (52 to 98%); positive predictive value, 67% (22 to 96%); negative predictive value, 100% (69 to 100%); positive likelihood ratio, 6.0 (1.58 to 19.4); and negative likelihood ratio, 0 (0 to 0.6). Results indicate good inter-tester reliability and suggest that the slump knee bend test has potential to be a useful clinical test for identifying patients with mid lumbar nerve root compression. Further investigation is needed on larger numbers of patients to confirm these findings. Copyright © 2010 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Particles and microfluidics merged: perspectives of highly sensitive diagnostic detection

PubMed Central

Bale, Shyam Sundhar; Bhushan, Abhinav; Shen, Keyue; Seker, Erkin; Polyak, Boris

2014-01-01

There is a growing need for diagnostic technologies that provide laboratories with solutions that improve quality, enhance laboratory system productivity, and provide accurate detection of a broad range of infectious diseases and cancers. Recent advances in micro- and nanoscience and engineering, in particular in the areas of particles and microfluidic technologies, have advanced the “lab-on-a-chip” concept towards the development of a new generation of point-of-care diagnostic devices that could significantly enhance test sensitivity and speed. In this review, we will discuss many of the recent advances in microfluidics and particle technologies with an eye towards merging these two technologies for application in medical diagnostics. Although the potential diagnostic applications are virtually unlimited, the most important applications are foreseen in the areas of biomarker research, cancer diagnosis, and detection of infectious microorganisms. PMID:25378716

The Relationship between Diagnostic Accuracy and Confidence in Medical Students.

ERIC Educational Resources Information Center

Mann, Doug

Studies in psychology and clinical decision making have shown that research subjects and physicians are often overconfident in the accuracy of their judgments. In these studies, groups of 20 first-year and 27 third-year osteopathic medical students at the Ohio University College of Osteopathic Medicine (Athens) were slightly underconfident in…

Severe Intellectual Disability: Systematic Review of the Prevalence and Nature of Presentation of Unipolar Depression

ERIC Educational Resources Information Center

Walton, Catherine; Kerr, Mike

2016-01-01

Background: The diagnosis of depression in severe and profound intellectual disability is challenging. Without adequate skills in verbal self-expression, standardized diagnostic criteria cannot be used with confidence. The purpose of this systematic review was to investigate the assessment and diagnosis of unipolar depression in severe and…

Special physical examination tests for superior labrum anterior posterior shoulder tears are clinically limited and invalid: a diagnostic systematic review.

PubMed

Calvert, Eric; Chambers, Gordon Keith; Regan, William; Hawkins, Robert H; Leith, Jordan M

2009-05-01

The diagnosis of a superior labrum anterior posterior (SLAP) lesion through physical examination has been widely reported in the literature. Most of these studies report high sensitivities and specificities, and claim to be accurate, valid, and reliable. The purpose of this study was to critically evaluate these studies to determine if there was sufficient evidence to support the use of the SLAP physical examination tests as valid and reliable diagnostic test procedures. Strict epidemiologic methodology was used to obtain and collate all relevant articles. Sackett's guidelines were applied to all articles. Confidence intervals and likelihood ratios were determined. Fifteen of 29 relevant studies met the criteria for inclusion. Only one article met all of Sackett's critical appraisal criteria. Confidence intervals for both the positive and negative likelihood ratios contained the value 1. The current literature being used as a resource for teaching in medical schools and continuing education lacks the validity necessary to be useful. There are no good physical examination tests that exist for effectively diagnosing a SLAP lesion.

[Malignant and benign diseases of the breast in 41 male patients: mammography, sonography and pathohistological correlations].

PubMed

Partik, B; Mallek, R; Rudas, M; Pokieser, P; Wunderbaldinger, P; Helbich, T H

2001-11-01

The goal of our study was to evaluate findings in mammography and sonography in male patients with pathohistologically proven diseases of the breast. Mammographies and sonographies, which were obtained in 41 male patients in a 6-year period, were retrospectively evaluated in accordance with the BI-RADS(R) classification. Histologically 13 carcinomas, 21 gynecomastias, 3 pseudogynecomastias, 2 epithelial inclusion cysts and 2 other benign lesions were diagnosed. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of mammography in differentiation of benign versus malignant disease were 92 %, 89 %, 80 %, 96 % and 90 %, respectively. Additional sonography did not change these results. However, sonography increased diagnostic confidence in 18.2 % (2/11) of suspicious lesions. In our study the invasive ductal carcinoma of male patients was a predominantly lobulated, ill-defined lesion in mammography and sonography. The differentiation of carcinoma to pseudogynecomastia and diffuse or dendritic gynecomastia was securely feasible. However, we could not reliably distinguish between carcinoma and some benign mass lesions. In cases of mammographically diagnosed masses or unclear mammography, additional sonography should be performed to increase the diagnostic confidence.

Diagnostic packages can be assigned accurately in emergency departments. A multi-centre cohort study.

PubMed

Nørgaard, Birgitte; Mogensen, Christian Backer; Teglbjærg, Lars Stubbe; Brabrand, Mikkel; Lassen, Annmarie Touborg

2016-06-01

In the Region of Southern Denmark, the emergency departments categorise patients based on presenting symptoms and a proposed diagnostic package (n = 40) within each category. The diagnostic packages describe relevant clinical information and standard laboratory and other investigations to be performed. Allocation to the right diagnostic package is assumed to be associated with a higher quality. The aim of this study was to describe to which degree the assigned symptom-based diagnostic packages are related to relevant discharge diagnoses. This was a descriptive cohort study. The analysis was based on data on assigned diagnostic package, patient discharge diagnosis, hospital, gender, age, time of admission and discharge, length of stay, diagnostic package assigned, discharge diagnosis and co-morbidity. An acceptable standard for what would be an appropriate primarily diagnostic package was developed using a modified Delphi method. A total of 16,543 patient contacts were identified. Women constituted 52.2% (n = 8,925) of the patients. The median age was 64 years and the median length of stay was one day. All diagnostic packages were represented. A total of 68% of the included patients had been assigned an acceptable diagnostic package (95% confidence interval: 67.2-68.7). We found an appropriate use of one of 30 diagnostic packages in more than 50% of the cases. We found that 68% of the included patients were assigned an acceptable diagnostic package and that about 80% of all acute pathways were covered by 14 diagnostic packages. The study was funded by Region of Southern Denmark. The study was registered with the Danish Data Protection Agency (No. 2008-58-0035). No further approval was required.

Application of Computational Toxicology to Prospective and Diagnostic Ecological Risk Assessment

EPA Pesticide Factsheets

Application of Computational Toxicology to Prospective and Diagnostic Ecological Risk Assessment (Presented by: Dan Villeneuve, Ph.D., Research Toxicologist, US-EPA Mid-Continent Ecology Division) (1/24/2013)

Applicability of the 2001 revised diagnostic criteria in Brazilian Vogt-Koyanagi-Harada disease patients.

PubMed

Cardoso, Isabel Habeyche; Zajdenweber, Moysés Eduardo; Muccioli, Cristina; Fimamor, Luciana Peixoto; Belfort, Rubens

2008-01-01

To determine the applicability of the international revised diagnostic criteria for Vogt-Koyanagi-Harada disease. Retrospective study. Medical charts of 140 patients with the diagnosis of Vogt-Koyanagi-Harada disease, from the Uveitis Sector of the Federal University of Sao Paulo (UNIFESP), were revised and classified following the revised diagnostic criteria. Of the 140 patients, 12.85% fulfilled the criteria for complete disease, 29.28% incomplete disease, 28.57% "probable" Vogt-Koyanagi-Harada disease and 28.27% were considered not Vogt-Koyanagi-Harada disease. The authors consider that the international revised diagnostic criteria have good applicability and are very useful to help in the diagnosis of Vogt-Koyanagi-Harada disease.

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.

Using Informatics and the Electronic Medical Record to Describe Antimicrobial Use in the Clinical Management of Diarrhea Cases at 12 Companion Animal Practices

PubMed Central

Anholt, R. Michele; Berezowski, John; Ribble, Carl S.; Russell, Margaret L.; Stephen, Craig

2014-01-01

Antimicrobial drugs may be used to treat diarrheal illness in companion animals. It is important to monitor antimicrobial use to better understand trends and patterns in antimicrobial resistance. There is no monitoring of antimicrobial use in companion animals in Canada. To explore how the use of electronic medical records could contribute to the ongoing, systematic collection of antimicrobial use data in companion animals, anonymized electronic medical records were extracted from 12 participating companion animal practices and warehoused at the University of Calgary. We used the pre-diagnostic, clinical features of diarrhea as the case definition in this study. Using text-mining technologies, cases of diarrhea were described by each of the following variables: diagnostic laboratory tests performed, the etiological diagnosis and antimicrobial therapies. The ability of the text miner to accurately describe the cases for each of the variables was evaluated. It could not reliably classify cases in terms of diagnostic tests or etiological diagnosis; a manual review of a random sample of 500 diarrhea cases determined that 88/500 (17.6%) of the target cases underwent diagnostic testing of which 36/88 (40.9%) had an etiological diagnosis. Text mining, compared to a human reviewer, could accurately identify cases that had been treated with antimicrobials with high sensitivity (92%, 95% confidence interval, 88.1%–95.4%) and specificity (85%, 95% confidence interval, 80.2%–89.1%). Overall, 7400/15,928 (46.5%) of pets presenting with diarrhea were treated with antimicrobials. Some temporal trends and patterns of the antimicrobial use are described. The results from this study suggest that informatics and the electronic medical records could be useful for monitoring trends in antimicrobial use. PMID:25057893

MR arthrography of the hip: diagnostic performance and image quality of 3D-steady state free precession versus 2D turbo spin echo sequences.

PubMed

Kraus, Mareen Sarah; Notohamiprodjo, Mike; Partovi, Sasan; Sobieh, Ahmed; Baur-Melnyk, Andrea; Hausdorf, Joerg; Grosse, Ulrich

2018-06-01

To retrospectively compare the diagnostic performance of isotropic 3D steady-state free precession (3D-SSFP) sequences with 2D turbo spin-echo proton density-weighted fat-saturated (2D-TSE-PD fs) images in hip magnetic resonance arthrography; arthroscopy was a standard of reference. Eighty-one patients with suspected labral tears who underwent hip MR arthrography (3-T scanner) were included. 2D-TSE-PD fs sequences were acquired in three planes and a singular sagittal 3D-SSFP. Labral tears, cartilage pathology and bone marrow were independently assessed by two blinded radiologists using a 5-point Likert scale. Accuracy was determined in 39 patients using invasive arthroscopy. Diagnostic confidence of labral and cartilaginous pathologies based on image quality was rated higher for 3D-SSFP (4.5 ± 0.8; 4.35 ± 0.7; p < 0.0001), but inferior for bone marrow pathology (3.9 ± 0.7; 4.0 ± 0.7; p < 0.0001). In the arthroscopy patients, similar sensitivity (85.9%) but higher specificity (74.4vs.42.9%) and higher positive and negative predictive values were found in 3D-SSFP of labral and cartilage pathologies. 3D-SSFP in hip magnetic resonance arthrography offers increased accuracy in detecting labral and cartilage pathologies compared with 2D-TSE-PD, while reducing the acquisition time. A drawback of 3D-SSFP was the inferior diagnostic confidence for bone marrow evaluation; thus, 3D-SSFP should be combined with conventional 2D-TSE sequences.

Using informatics and the electronic medical record to describe antimicrobial use in the clinical management of diarrhea cases at 12 companion animal practices.

PubMed

Anholt, R Michele; Berezowski, John; Ribble, Carl S; Russell, Margaret L; Stephen, Craig

2014-01-01

Antimicrobial drugs may be used to treat diarrheal illness in companion animals. It is important to monitor antimicrobial use to better understand trends and patterns in antimicrobial resistance. There is no monitoring of antimicrobial use in companion animals in Canada. To explore how the use of electronic medical records could contribute to the ongoing, systematic collection of antimicrobial use data in companion animals, anonymized electronic medical records were extracted from 12 participating companion animal practices and warehoused at the University of Calgary. We used the pre-diagnostic, clinical features of diarrhea as the case definition in this study. Using text-mining technologies, cases of diarrhea were described by each of the following variables: diagnostic laboratory tests performed, the etiological diagnosis and antimicrobial therapies. The ability of the text miner to accurately describe the cases for each of the variables was evaluated. It could not reliably classify cases in terms of diagnostic tests or etiological diagnosis; a manual review of a random sample of 500 diarrhea cases determined that 88/500 (17.6%) of the target cases underwent diagnostic testing of which 36/88 (40.9%) had an etiological diagnosis. Text mining, compared to a human reviewer, could accurately identify cases that had been treated with antimicrobials with high sensitivity (92%, 95% confidence interval, 88.1%-95.4%) and specificity (85%, 95% confidence interval, 80.2%-89.1%). Overall, 7400/15,928 (46.5%) of pets presenting with diarrhea were treated with antimicrobials. Some temporal trends and patterns of the antimicrobial use are described. The results from this study suggest that informatics and the electronic medical records could be useful for monitoring trends in antimicrobial use.

A new SPECT/CT reconstruction algorithm: reliability and accuracy in clinical routine for non-oncologic bone diseases.

PubMed

Delcroix, Olivier; Robin, Philippe; Gouillou, Maelenn; Le Duc-Pennec, Alexandra; Alavi, Zarrin; Le Roux, Pierre-Yves; Abgral, Ronan; Salaun, Pierre-Yves; Bourhis, David; Querellou, Solène

2018-02-12

xSPECT Bone® (xB) is a new reconstruction algorithm developed by Siemens® in bone hybrid imaging (SPECT/CT). A CT-based tissue segmentation is incorporated into SPECT reconstruction to provide SPECT images with bone anatomy appearance. The objectives of this study were to assess xB/CT reconstruction diagnostic reliability and accuracy in comparison with Flash 3D® (F3D)/CT in clinical routine. Two hundred thirteen consecutive patients referred to the Brest Nuclear Medicine Department for non-oncological bone diseases were evaluated retrospectively. Two hundred seven SPECT/CT were included. All SPECT/CT were independently interpreted by two nuclear medicine physicians (a junior and a senior expert) with xB/CT then with F3D/CT three months later. Inter-observer agreement (IOA) and diagnostic confidence were determined using McNemar test, and unweighted Kappa coefficient. The study objectives were then re-assessed for validation through > 18 months of clinical and paraclinical follow-up. No statistically significant differences between IOA xB and IOA F3D were found (p = 0.532). Agreement for xB after categorical classification of the diagnoses was high (κ xB = 0.89 [95% CI 0.84 -0.93]) but without statistically significant difference F3D (κ F3D = 0.90 [95% CI 0.86 - 0.94]). Thirty-one (14.9%) inter-reconstruction diagnostic discrepancies were observed of which 21 (10.1%) were classified as major. The follow-up confirmed the diagnosis of F3D in 10 cases, xB in 6 cases and was non-contributory in 5 cases. xB reconstruction algorithm was found reliable, providing high interobserver agreement and similar diagnostic confidence to F3D reconstruction in clinical routine.

Racial and ethnic differences in patient navigation: Results from the Patient Navigation Research Program.

PubMed

Ko, Naomi Y; Snyder, Frederick R; Raich, Peter C; Paskett, Electra D; Dudley, Donald J; Lee, Ji-Hyun; Levine, Paul H; Freund, Karen M

2016-09-01

Patient navigation was developed to address barriers to timely care and reduce cancer disparities. The current study explored navigation and racial and ethnic differences in time to the diagnostic resolution of a cancer screening abnormality. The authors conducted an analysis of the multisite Patient Navigation Research Program. Participants with an abnormal cancer screening test were allocated to either navigation or control. The unadjusted median time to resolution was calculated for each racial and ethnic group by navigation and control. Multivariable Cox proportional hazards models were fit, adjusting for sex, age, cancer abnormality type, and health insurance and stratifying by center of care. Among a sample of 7514 participants, 29% were non-Hispanic white, 43% were Hispanic, and 28% were black. In the control group, black individuals were found to have a longer median time to diagnostic resolution (108 days) compared with non-Hispanic white individuals (65 days) or Hispanic individuals (68 days) (P<.0001). In the navigated groups, black individuals had a reduction in the median time to diagnostic resolution (97 days) (P<.0001). In the multivariable models, among controls, black race was found to be associated with an increased delay to diagnostic resolution (hazard ratio, 0.77; 95% confidence interval, 0.69-0.84) compared with non-Hispanic white individuals, which was reduced in the navigated arm (hazard ratio, 0.85; 95% confidence interval, 0.77-0.94). Patient navigation appears to have the greatest impact among black patients, who had the greatest delays in care. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2715-2722. © 2016 American Cancer Society. © 2016 American Cancer Society.

Improvement in diagnostic performance of breast cancer: comparison between conventional digital mammography alone and conventional mammography plus digital breast tomosynthesis.

PubMed

Ohashi, Ryoko; Nagao, Michinobu; Nakamura, Izumi; Okamoto, Takahiro; Sakai, Shuji

2018-04-12

The aim of this study was to determine if the diagnostic performance of breast lesion examinations could be improved using both digital breast tomosynthesis (DBT) and conventional digital mammography (CDM). Our institutional review board approved the protocol, and patients were provided the opportunity to opt out of the study. A total of 628 patients aged 22-91 years with abnormal screening results or clinical symptoms were consecutively enrolled between June 2015 and March 2016. All patients underwent DBT and CDM, and 1164 breasts were retrospectively analyzed by three radiologists who interpreted the results based on the Breast Imaging Reporting and Data System. Categories 4 and 5 were considered positive, and pathological results were the gold standard. The diagnostic performance of CDM and CDM plus DBT was compared using the mean areas under the receiver operating characteristic (ROC) curves. A total of 100 breast cancer cases were identified. The areas under the ROC curves were 0.9160 (95% confidence interval 0.8779-0.9541) for CDM alone and 0.9376 (95% confidence interval 0.9019-0.9733) for CDM plus DBT. The cut-off values for both CDM alone and CDM plus DBT measurements were 4, with sensitivities of 61.0% (61/100) and 83.0% (83/100), respectively, and specificities of 99.1% (1054/1064) and 98.9% (1052/1064), respectively. CDM yielded 39 false-negative diagnoses, while CDM plus DBT identified breast cancer in 22 of those cases (56.4%). The combination of DBT and CDM for the diagnosis of breast cancer in women with abnormal examination findings or clinical symptoms proved effective and should be used to improve the diagnostic performance of breast cancer examinations.

Diagnostics vehicle’s condition using obd-ii and raspberry pi technology: study literature

NASA Astrophysics Data System (ADS)

Moniaga, J. V.; Manalu, S. R.; Hadipurnawan, D. A.; Sahidi, F.

2018-03-01

Transportation accident rate are still being a major challenge in many countries. There are many factors that could be cause transportation accident, especially in vehicle’s internal system problem. To overcome this problem, OBD-II technology has been created to diagnostics vehicle’s condition. OBD-II scanner plugged to OBD-II port or usually called Data Link Connector (DLC), and after that it sends the diagnostics to Raspberry Pi. Compared from another microcontrollers, Arduino, Raspberry Pi are chosen because it sustains the application to receive real-time diagnostics, process the diagnostics and send command to automobiles at the same time, rather than Arduino that must wait for another process finished to run another process. Outcome from this application is to enable automobile’s user to diagnostics their own vehicles. If there is found something unusual or a problem, the application can told the problem to user, so they could know what to fix before they use their vehicle safely.

Four applications of permutation methods to testing a single-mediator model.

PubMed

Taylor, Aaron B; MacKinnon, David P

2012-09-01

Four applications of permutation tests to the single-mediator model are described and evaluated in this study. Permutation tests work by rearranging data in many possible ways in order to estimate the sampling distribution for the test statistic. The four applications to mediation evaluated here are the permutation test of ab, the permutation joint significance test, and the noniterative and iterative permutation confidence intervals for ab. A Monte Carlo simulation study was used to compare these four tests with the four best available tests for mediation found in previous research: the joint significance test, the distribution of the product test, and the percentile and bias-corrected bootstrap tests. We compared the different methods on Type I error, power, and confidence interval coverage. The noniterative permutation confidence interval for ab was the best performer among the new methods. It successfully controlled Type I error, had power nearly as good as the most powerful existing methods, and had better coverage than any existing method. The iterative permutation confidence interval for ab had lower power than do some existing methods, but it performed better than any other method in terms of coverage. The permutation confidence interval methods are recommended when estimating a confidence interval is a primary concern. SPSS and SAS macros that estimate these confidence intervals are provided.

A Diagnostic Marker to Discriminate Childhood Apraxia of Speech From Speech Delay: II. Validity Studies of the Pause Marker.

PubMed

Shriberg, Lawrence D; Strand, Edythe A; Fourakis, Marios; Jakielski, Kathy J; Hall, Sheryl D; Karlsson, Heather B; Mabie, Heather L; McSweeny, Jane L; Tilkens, Christie M; Wilson, David L

2017-04-14

The purpose of this 2nd article in this supplement is to report validity support findings for the Pause Marker (PM), a proposed single-sign diagnostic marker of childhood apraxia of speech (CAS). PM scores and additional perceptual and acoustic measures were obtained from 296 participants in cohorts with idiopathic and neurogenetic CAS, adult-onset apraxia of speech and primary progressive apraxia of speech, and idiopathic speech delay. Adjusted for questionable specificity disagreements with a pediatric Mayo Clinic diagnostic standard, the estimated sensitivity and specificity, respectively, of the PM were 86.8% and 100% for the CAS cohort, yielding positive and negative likelihood ratios of 56.45 (95% confidence interval [CI]: [1.15, 2763.31]) and 0.13 (95% CI [0.06, 0.30]). Specificity of the PM for 4 cohorts totaling 205 participants with speech delay was 98.5%. These findings are interpreted as providing support for the PM as a near-conclusive diagnostic marker of CAS.

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.

Quantitative optical diagnostics in pathology recognition and monitoring of tissue reaction to PDT

NASA Astrophysics Data System (ADS)

Kirillin, Mikhail; Shakhova, Maria; Meller, Alina; Sapunov, Dmitry; Agrba, Pavel; Khilov, Alexander; Pasukhin, Mikhail; Kondratieva, Olga; Chikalova, Ksenia; Motovilova, Tatiana; Sergeeva, Ekaterina; Turchin, Ilya; Shakhova, Natalia

2017-07-01

Optical coherence tomography (OCT) is currently actively introduced into clinical practice. Besides diagnostics, it can be efficiently employed for treatment monitoring allowing for timely correction of the treatment procedure. In monitoring of photodynamic therapy (PDT) traditionally employed fluorescence imaging (FI) can benefit from complementary use of OCT. Additional diagnostic efficiency can be derived from numerical processing of optical diagnostics data providing more information compared to visual evaluation. In this paper we report on application of OCT together with numerical processing for clinical diagnostic in gynecology and otolaryngology, for monitoring of PDT in otolaryngology and on OCT and FI applications in clinical and aesthetic dermatology. Image numerical processing and quantification provides increase in diagnostic accuracy. Keywords: optical coherence tomography, fluorescence imaging, photod

Setting Hurricane Conditions of Readiness with High Confidence.

DTIC Science & Technology

1984-05-01

AD-A144 785SETTING HURRICANE CONDITIONS OF READINESS WITH HIGH i/ CONFIDENCE(U) SCIENCE APPLICATIONS INC MONTEREY CA G KOSTYSHACK ET AL. MAY 84 NEPRF...HIGH CONFIDENCE CA qtJ V m r"Prepared By: Geoff Kostyshack and Jerry Jarrell -- Science Applications, Inc. Monterey, California 93940 Contract No...N00228-83-C-3079 DTIC ELECTE AUG2 3 lg4 MAY 1984 SS APPROVED FOR PUBLIC RELEASE; DISTRIBUTION IS UNLIMITED Prepared For: INAVAL ENVIRONMENTAL PREDICTION

Radiation dose-reduction strategies in thoracic CT.

PubMed

Moser, J B; Sheard, S L; Edyvean, S; Vlahos, I

2017-05-01

Modern computed tomography (CT) machines have the capability to perform thoracic CT for a range of clinical indications at increasingly low radiation doses. This article reviews several factors, both technical and patient-related, that can affect radiation dose and discusses current dose-reduction methods relevant to thoracic imaging through a review of current techniques in CT acquisition and image reconstruction. The fine balance between low radiation dose and high image quality is considered throughout, with an emphasis on obtaining diagnostic quality imaging at the lowest achievable radiation dose. The risks of excessive radiation dose reduction are also considered. Inappropriately low dose may result in suboptimal or non-diagnostic imaging that may reduce diagnostic confidence, impair diagnosis, or result in repeat examinations incurring incremental ionising radiation exposure. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

University of Saskatchewan Radiology Courseware (USRC): an assessment of its utility for teaching diagnostic imaging in the medical school curriculum.

PubMed

Burbridge, Brent; Kalra, Neil; Malin, Greg; Trinder, Krista; Pinelle, David

2015-01-01

We have found it very challenging to integrate images from our radiology digital imaging repository into the curriculum of our local medical school. Thus, it has been difficult to convey important knowledge related to viewing and interpreting diagnostic radiology images. We sought to determine if we could create a solution for this problem and evaluate whether students exposed to this solution were able to learn imaging concepts pertinent to medical practice. We developed University of Saskatchewan Radiology Courseware (USRC), a novel interactive web application that enables preclinical medical students to acquire image interpretation skills fundamental to clinical practice. This web application reformats content stored in Medical Imaging Resource Center teaching cases for BlackBoard Learn™, a popular learning management system. We have deployed this solution for 2 successive years in a 1st-year basic sciences medical school course at the College of Medicine, University of Saskatchewan. The "courseware" content covers both normal anatomy and common clinical pathologies in five distinct modules. We created two cohorts of learners consisting of an intervention cohort of students who had used USRC for their 1st academic year, whereas the nonintervention cohort was students who had not been exposed to this learning opportunity. To assess the learning experience of the users we designed an online questionnaire and image review quiz delivered to both of the student groups. Comparisons between the groups revealed statistically significant differences in both confidence with image interpretation and the ability to answer knowledge-based questions. Students were satisfied with the overall usability, functions, and capabilities of USRC. USRC is an innovative technology that provides integration between Medical Imaging Resource Center, a teaching solution used in radiology, and a Learning Management System.

Clinical Factors and Disease Course Related to Diagnostic Delay in Korean Crohn’s Disease Patients: Results from the CONNECT Study

PubMed Central

Moon, Chang Mo; Jung, Sung-Ae; Kim, Seong-Eun; Song, Hyun Joo; Jung, Yunho; Ye, Byong Duk; Cheon, Jae Hee; Kim, You Sun; Kim, Young-Ho; Kim, Joo Sung; Han, Dong Soo

2015-01-01

Diagnostic delay frequently occurs in Crohn’s disease (CD) patients because of diagnostic limitations. However, diagnostic delay and its related factors remain poorly defined. Therefore, we aimed to identify the predictors associated with diagnostic delay and to evaluate the impact of diagnostic delay on clinical course in a Korean CD patient cohort. We performed a multicenter retrospective analysis of 1,047 CD patients registered in the Crohn’s Disease Clinical Network and Cohort study in Korea. The mean interval of diagnostic delay was 16.0 ± 33.1 months. Multivariate analysis showed that older age at diagnosis (≥40 years) (p = 0.014), concomitant upper gastrointestinal (UGI) disease (p = 0.012) and penetrating disease behavior at diagnosis (p = 0.001) were positively associated with long diagnostic delay (≥18 months). During the longitudinal follow-up, long diagnostic delay was independently predictive of further development of intestinal stenosis (hazard ratio [HR], 1.43; 95% confidence interval [CI], 1.07–1.93; p = 0.017), internal fistulas (HR, 1.62; 95% CI, 1.12–2.33; p = 0.011), and perianal fistulas (HR, 1.38; 95% CI, 1.06–1.80; p = 0.016). However, as for the risk of abscess formation, bowel perforation, and CD-related abdominal surgery, no significant association with diagnostic delay was observed. Older age at diagnosis, UGI involvement, and penetrating behavior are associated with long diagnostic delay in Korean CD patients. Moreover, diagnostic delay is associated with an increased risk of CD-related complications such as intestinal stenosis, internal fistulas, and perianal fistulas. PMID:26647084

Using an R Shiny to Enhance the Learning Experience of Confidence Intervals

ERIC Educational Resources Information Center

Williams, Immanuel James; Williams, Kelley Kim

2018-01-01

Many students find understanding confidence intervals difficult, especially because of the amalgamation of concepts such as confidence levels, standard error, point estimates and sample sizes. An R Shiny application was created to assist the learning process of confidence intervals using graphics and data from the US National Basketball…

Identification of new diagnostic biomarkers for Mycobacterium tuberculosis and the potential application in the serodiagnosis of human tuberculosis.

PubMed

Ren, Ningning; JinLi, Jingfang; Chen, Yingyu; Zhou, Xia; Wang, Jieru; Ge, Pan; Khan, Farhan Anwar; Zhang, Li; Hu, Changmin; Robertson, Ian D; Chen, Huanchun; Guo, Aizhen

2018-06-27

Mycobacterium tuberculosis (M. tuberculosis) regions of difference (RD) encode proteins which are potentially useful as diagnostic reagents for tuberculosis (TB). In this study, 75 genes from M. tuberculosis RD1-RD16 were successfully cloned from which 68 proteins were expressed and purified. Three serum pools from patients with pulmonary TB (PTB), extra-pulmonary tuberculosis (EPTB) and healthy controls (HC) were used to preliminarily screen individual RD proteins. The OD 630 ratio of the PTB or EPTB to the HC group ≥ 2-fold was positive. As a result, 29 proteins were obtained. The serological response to the identified antigens was further verified using 58 PTB samples with 38 sera from smear-positive PTB (PTB-SP) patients and 20 sera from smear-negative PTB (PTB-SN) patients, 16 EPTB samples, 42 latent M. tuberculosis infection samples and 40 HCs by indirect ELISA. With respect to the PTB diagnosis, receiver operating characteristic analysis showed that Rv0222 [area under the curve (AUC), 0.8129; 95% confidence interval (CI), 0.7280-0.8979] and Rv3403c (AUC, 0.8537; 95% CI, 0.7779-0.9294) performed better than ESAT6/CFP10 (AUC, 0.7435; 95% CI, 0.6465-0.8406). Rv0222 and Rv3403c demonstrated the highest diagnostic ability in the PTB-SP group (sensitivity, 86.8%; specificity, 80%), while Rv3403c demonstrated the highest diagnostic ability in the PTB-SN group (sensitivity, 70%; specificity, 80%). With respect to the EPTB diagnosis, Rv0222 exhibited the highest diagnostic value (AUC, 0.7523; sensitivity, 68.8%; specificity, 87.5%). In addition, the combination of Rv0222 and Rv3403c improved the test for PTB-SN. These results indicate that Rv0222 and Rv3403c would be potential diagnostic biomarkers for active TB serodiagnosis. Mouse experiments demonstrated that Rv0222 and Rv3403c elicited specific cellular and humoral responses which were characterized by production of IFN-γ, IgG1, and IgG2a, but a higher level of IgG1 than IgG2a. © 2018 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Application of loop-mediated isothermal amplification assay for the sensitive and rapid diagnosis of visceral leishmaniasis and post-kala-azar dermal leishmaniasis.

PubMed

Verma, Sandeep; Avishek, Kumar; Sharma, Vanila; Negi, Narendra Singh; Ramesh, Venkatesh; Salotra, Poonam

2013-04-01

Loop-mediated isothermal amplification (LAMP) is at the forefront in the search for innovative diagnostics for rapid and specific amplification of target DNA under isothermal conditions. We have applied LAMP assay using SYBR Green for clear-cut naked eye detection of Leishmania (Leishmania) donovani in 200 clinical samples of visceral leishmaniasis (VL) and post-kala-azar dermal leishmaniasis (PKDL). The assay was positive in 53/55 VL blood samples (sensitivity, 96.4%; 95% confidence interval [CI], 87.7-99%), 15/15 VL bone marrow aspirate samples (sensitivity, 100%; 95% CI, 79.6-100%), 60/62 PKDL tissue biopsy samples (sensitivity, 96.8%; 95% CI, 88.9-99.1%), and 1/68 control samples (specificity, 98.5%; 95% CI, 92.1-99.7%). The assay was specific for L. (L.) donovani, the causative species for VL and negative for L. (L.) infantum, L. (L.) tropica, and L. (L.) major. This is the first comprehensive clinical study demonstrating the applicability of the LAMP assay for a rapid and reliable molecular diagnosis of VL and PKDL. Copyright © 2013 Elsevier Inc. All rights reserved.

37 CFR 1.14 - Patent applications preserved in confidence.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Patent applications preserved in confidence. 1.14 Section 1.14 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES General Provisions...

37 CFR 1.14 - Patent applications preserved in confidence.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 37 Patents, Trademarks, and Copyrights 1 2014-07-01 2014-07-01 false Patent applications preserved in confidence. 1.14 Section 1.14 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES General Provisions...

37 CFR 1.14 - Patent applications preserved in confidence.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 37 Patents, Trademarks, and Copyrights 1 2012-07-01 2012-07-01 false Patent applications preserved in confidence. 1.14 Section 1.14 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES General Provisions...

37 CFR 1.14 - Patent applications preserved in confidence.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Patent applications preserved in confidence. 1.14 Section 1.14 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES General Provisions...

Conflict management, Part 1. Conflict management checklist: a diagnostic tool for assessing conflict in organizations.

PubMed

Siders, C T; Aschenbrener, C A

1999-01-01

Complex interpersonal conflicts are inevitable in the high speed, high stakes, pressured work of health care. Poorly managed, conflict saps productivity, erodes trust, and spawns additional disputes. Well managed, conflict can enhance the self-confidence and self-esteem of the parties, build relationships, and engender creative solutions beyond expectations. Just as thoughtful differential diagnosis precedes optimum treatment in the doctor-patient relationship, management of conflict is greatly enhanced when preceded by careful assessment. In the first of two articles, the authors present a diagnostic approach, the Conflict Management Checklist, to increase self-awareness and decrease anxiety around conflict.

Laboratory study of the spectrum of highly ionized calcium in the 100-250 A range applied to solar flare diagnostics

NASA Technical Reports Server (NTRS)

Lippmann, S.; Finkenthal, M.; Huang, L. K.; Moos, H. W.; Stratton, B. C.; Yu, T. L.; Bhatia, A. K.

1987-01-01

Calcium was introduced into the TEXT tokamak, and its spectral emission was recorded in the 50-360 A range by an absolutely calibrated grazing incidence spectrometer. These observations of highly ionized species of calcium at known conditions of plasma electron temperature and density allow testing of line brightness ratio predictions based on theoretical values of temperature-dependent electron excitation rates. The confirmation of the expected ratios in Be I-like to O I-like calcium allows more confident use of these ratios as a density diagnostic of remote astrophysical sources such as solar flares.

Application of gray level mapping in computed tomographic colonography: a pilot study to compare with traditional surface rendering method for identification and differentiation of endoluminal lesions

PubMed Central

Chen, Lih-Shyang; Hsu, Ta-Wen; Chang, Shu-Han; Lin, Chih-Wen; Chen, Yu-Ruei; Hsieh, Chin-Chiang; Han, Shu-Chen; Chang, Ku-Yaw; Hou, Chun-Ju

2017-01-01

Objective: In traditional surface rendering (SR) computed tomographic endoscopy, only the shape of endoluminal lesion is depicted without gray-level information unless the volume rendering technique is used. However, volume rendering technique is relatively slow and complex in terms of computation time and parameter setting. We use computed tomographic colonography (CTC) images as examples and report a new visualization technique by three-dimensional gray level mapping (GM) to better identify and differentiate endoluminal lesions. Methods: There are 33 various endoluminal cases from 30 patients evaluated in this clinical study. These cases were segmented using gray-level threshold. The marching cube algorithm was used to detect isosurfaces in volumetric data sets. GM is applied using the surface gray level of CTC. Radiologists conducted the clinical evaluation of the SR and GM images. The Wilcoxon signed-rank test was used for data analysis. Results: Clinical evaluation confirms GM is significantly superior to SR in terms of gray-level pattern and spatial shape presentation of endoluminal cases (p < 0.01) and improves the confidence of identification and clinical classification of endoluminal lesions significantly (p < 0.01). The specificity and diagnostic accuracy of GM is significantly better than those of SR in diagnostic performance evaluation (p < 0.01). Conclusion: GM can reduce confusion in three-dimensional CTC and well correlate CTC with sectional images by the location as well as gray-level value. Hence, GM increases identification and differentiation of endoluminal lesions, and facilitates diagnostic process. Advances in knowledge: GM significantly improves the traditional SR method by providing reliable gray-level information for the surface points and is helpful in identification and differentiation of endoluminal lesions according to their shape and density. PMID:27925483

Diagnostic accuracy and reproducibility of the Ottawa Knee Rule vs the Pittsburgh Decision Rule.

PubMed

Cheung, Tung C; Tank, Yeliz; Breederveld, Roelf S; Tuinebreijer, Wim E; de Lange-de Klerk, Elly S M; Derksen, Robert J

2013-04-01

The aim of this present study was to compare the diagnostic accuracy and reproducibility of 2 clinical decision rules (the Ottawa Knee Rules [OKR] and Pittsburgh Decision Rules [PDR]) developed for selective use of x-rays in the evaluation of isolated knee trauma. Application of a decision rule leads to a more efficient evaluation of knee injuries and a reduction in health care costs. The diagnostic accuracy and reproducibility are compared in this study. A cross-sectional interobserver study was conducted in the emergency department of an urban teaching hospital from October 2008 to July 2009. Two observer groups collected data on standardized case-report forms: emergency medicine residents and surgical residents. Standard knee radiographs were performed in each patient. Participants were patients 18 years and older with isolated knee injuries. Pooled sensitivity and specificity were compared using χ(2) statistics, and interobserver agreement was calculated by using κ statistics. Ninety injuries were assessed. Seven injuries concerned fractures (7.8%). For the OKR, the pooled sensitivity and specificity were 0.86 (95% confidence interval [CI], 0.57-0.96) and 0.27 (95% CI, 0.21-0.35), respectively. The PDR had a pooled sensitivity and specificity of 0.86 (95% CI, 0.57-0.96) and 0.51 (95% CI, 0.44-0.59). The PDR was significantly (P = .002) more specific. The κ values for the OKR and PDR were 0.51 (95% CI, 0.32-0.71) and 0.71 (95% CI, 0.57-0.86), respectively. The PDR was found to be more specific than the OKR, with equal sensitivity. Interobserver agreement was moderate for the OKR and substantial for the PDR. Copyright © 2013 Elsevier Inc. All rights reserved.

Machine learning: a useful radiological adjunct in determination of a newly diagnosed glioma's grade and IDH status.

PubMed

De Looze, Céline; Beausang, Alan; Cryan, Jane; Loftus, Teresa; Buckley, Patrick G; Farrell, Michael; Looby, Seamus; Reilly, Richard; Brett, Francesca; Kearney, Hugh

2018-05-16

Machine learning methods have been introduced as a computer aided diagnostic tool, with applications to glioma characterisation on MRI. Such an algorithmic approach may provide a useful adjunct for a rapid and accurate diagnosis of a glioma. The aim of this study is to devise a machine learning algorithm that may be used by radiologists in routine practice to aid diagnosis of both: WHO grade and IDH mutation status in de novo gliomas. To evaluate the status quo, we interrogated the accuracy of neuroradiology reports in relation to WHO grade: grade II 96.49% (95% confidence intervals [CI] 0.88, 0.99); III 36.51% (95% CI 0.24, 0.50); IV 72.9% (95% CI 0.67, 0.78). We derived five MRI parameters from the same diagnostic brain scans, in under two minutes per case, and then supplied these data to a random forest algorithm. Machine learning resulted in a high level of accuracy in prediction of tumour grade: grade II/III; area under the receiver operating characteristic curve (AUC) = 98%, sensitivity = 0.82, specificity = 0.94; grade II/IV; AUC = 100%, sensitivity = 1.0, specificity = 1.0; grade III/IV; AUC = 97%, sensitivity = 0.83, specificity = 0.97. Furthermore, machine learning also facilitated the discrimination of IDH status: AUC of 88%, sensitivity = 0.81, specificity = 0.77. These data demonstrate the ability of machine learning to accurately classify diffuse gliomas by both WHO grade and IDH status from routine MRI alone-without significant image processing, which may facilitate usage as a diagnostic adjunct in clinical practice.

The Buffer Diagnostic Prototype: A fault isolation application using CLIPS

NASA Technical Reports Server (NTRS)

Porter, Ken

1994-01-01

This paper describes problem domain characteristics and development experiences from using CLIPS 6.0 in a proof-of-concept troubleshooting application called the Buffer Diagnostic Prototype. The problem domain is a large digital communications subsystems called the real-time network (RTN), which was designed to upgrade the launch processing system used for shuttle support at KSC. The RTN enables up to 255 computers to share 50,000 data points with millisecond response times. The RTN's extensive built-in test capability but lack of any automatic fault isolation capability presents a unique opportunity for a diagnostic expert system application. The Buffer Diagnostic Prototype addresses RTN diagnosis with a multiple strategy approach. A novel technique called 'faulty causality' employs inexact qualitative models to process test results. Experimental knowledge provides a capability to recognize symptom-fault associations. The implementation utilizes rule-based and procedural programming techniques, including a goal-directed control structure and simple text-based generic user interface that may be reusable for other rapid prototyping applications. Although limited in scope, this project demonstrates a diagnostic approach that may be adapted to troubleshoot a broad range of equipment.

Bone images from dual-energy subtraction chest radiography in the detection of rib fractures.

PubMed

Szucs-Farkas, Zsolt; Lautenschlager, Katrin; Flach, Patricia M; Ott, Daniel; Strautz, Tamara; Vock, Peter; Ruder, Thomas D

2011-08-01

To assess the sensitivity and image quality of chest radiography (CXR) with or without dual-energy subtracted (ES) bone images in the detection of rib fractures. In this retrospective study, 39 patients with 204 rib fractures and 24 subjects with no fractures were examined with a single exposure dual-energy subtraction digital radiography system. Three blinded readers first evaluated the non-subtracted posteroanterior and lateral chest radiographs alone, and 3 months later they evaluated the non-subtracted images together with the subtracted posteroanterior bone images. The locations of rib fractures were registered with confidence levels on a 3-grade scale. Image quality was rated on a 5-point scale. Marks by readers were compared with fracture localizations in CT as a standard of reference. The sensivity for fracture detection using both methods was very similar (34.3% with standard CXR and 33.5% with ES-CXR, p=0.92). At the patient level, both sensitivity (71.8%) and specificity (92.9%) with or without ES were identical. Diagnostic confidence was not significantly different (2.61 with CXR and 2.75 with ES-CXR, p=0.063). Image quality with ES was rated higher than that on standard CXR (4.08 vs. 3.74, p<0.001). Despite a better image quality, adding ES bone images to standard radiographs of the chest does not provide better sensitivity or improved diagnostic confidence in the detection of rib fractures. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Association of internet use and depression among the spinal cord injury population.

PubMed

Tsai, I-Hsuan; Graves, Daniel E; Lai, Ching-Huang; Hwang, Lu-Yu; Pompeii, Lisa A

2014-02-01

To examine the relation between the frequency of Internet use and depression among people with spinal cord injury (SCI). Cross-sectional survey. SCI Model Systems. People with SCI (N=4618) who were interviewed between 2004 and 2010. Not applicable. The frequency of Internet use and the severity of depressive symptoms were measured simultaneously by interview. Internet use was reported as daily, weekly, monthly, or none. The depressive symptoms were measured by the Patient Health Questionnaire-9 (PHQ-9), with 2 published criteria being used to screen for depressive disorder. The diagnostic method places more weight on nonsomatic items (ie, items 1, 2, and 9), and the cut-off method that determines depression by a (PHQ-9) score ≥10 places more weight on somatic factors. The average scores of somatic and nonsomatic items represented the severity of somatic and nonsomatic symptoms, respectively. Our multivariate logistic regression model indicated that daily Internet users were less likely to have depressive symptoms (odds ratio=.77; 95% confidence interval, .64-.93), if the diagnostic method was used. The linear multivariate regression analysis indicated that daily and weekly Internet usage were associated with fewer nonsomatic symptoms; no significant association was observed between daily or weekly Internet usage and somatic symptoms. People with SCI who used the Internet daily were less likely to have depressive symptoms. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Molecular Diagnosis and Biomarker Identification on SELDI proteomics data by ADTBoost method.

PubMed

Wang, Lu-Yong; Chakraborty, Amit; Comaniciu, Dorin

2005-01-01

Clinical proteomics is an emerging field that will have great impact on molecular diagnosis, identification of disease biomarkers, drug discovery and clinical trials in the post-genomic era. Protein profiling in tissues and fluids in disease and pathological control and other proteomics techniques will play an important role in molecular diagnosis with therapeutics and personalized healthcare. We introduced a new robust diagnostic method based on ADTboost algorithm, a novel algorithm in proteomics data analysis to improve classification accuracy. It generates classification rules, which are often smaller and easier to interpret. This method often gives most discriminative features, which can be utilized as biomarkers for diagnostic purpose. Also, it has a nice feature of providing a measure of prediction confidence. We carried out this method in amyotrophic lateral sclerosis (ALS) disease data acquired by surface enhanced laser-desorption/ionization-time-of-flight mass spectrometry (SELDI-TOF MS) experiments. Our method is shown to have outstanding prediction capacity through the cross-validation, ROC analysis results and comparative study. Our molecular diagnosis method provides an efficient way to distinguish ALS disease from neurological controls. The results are expressed in a simple and straightforward alternating decision tree format or conditional format. We identified most discriminative peaks in proteomic data, which can be utilized as biomarkers for diagnosis. It will have broad application in molecular diagnosis through proteomics data analysis and personalized medicine in this post-genomic era.

Recognition ROCS Are Curvilinear--Or Are They? On Premature Arguments against the Two-High-Threshold Model of Recognition

ERIC Educational Resources Information Center

Broder, Arndt; Schutz, Julia

2009-01-01

Recent reviews of recognition receiver operating characteristics (ROCs) claim that their curvilinear shape rules out threshold models of recognition. However, the shape of ROCs based on confidence ratings is not diagnostic to refute threshold models, whereas ROCs based on experimental bias manipulations are. Also, fitting predicted frequencies to…

High luminance monochrome vs. color displays: impact on performance and search

NASA Astrophysics Data System (ADS)

Krupinski, Elizabeth A.; Roehrig, Hans; Matsui, Takashi

2011-03-01

To determine if diagnostic accuracy and visual search efficiency with a high luminance medical-grade color display are equivalent to a high luminance medical-grade monochrome display. Six radiologists viewed DR chest images, half with a solitary pulmonary nodule and half without. Observers reported whether or not a nodule was present and their confidence in that decision. Total viewing time per image was recorded. On a subset of 15 cases eye-position was recorded. Confidence data were analyzed using MRMC ROC techniques. There was no statistically significant difference (F = 0.0136, p = 0.9078) between color (mean Az = 0.8981, se = 0.0065) and monochrome (mean Az = 0.8945, se = 0.0148) diagnostic performance. Total viewing time per image did not differ significantly (F = 0.392, p = 0.5315) as a function of color (mean = 27.36 sec, sd = 12.95) vs monochrome (mean = 28.04, sd = 14.36) display. There were no significant differences in decision dwell times (true and false, positive and negative) overall for color vs monochrome displays (F = 0.133, p = 0.7154). The true positive (TP) and false positive (FP) decisions were associated with the longest dwell times, the false negatives (FN) with slightly shorter dwell times, and the true negative decisions (TN) with the shortest (F = 50.552, p < 0.0001) and these trends were consistent for both color and monochrome displays. Current color medical-grade displays are suitable for primary diagnostic interpretation in clinical radiology.

The meaning of diagnostic test results: a spreadsheet for swift data analysis.

PubMed

Maceneaney, P M; Malone, D E

2000-03-01

To design a spreadsheet program to: (a) analyse rapidly diagnostic test result data produced in local research or reported in the literature; (b) correct reported predictive values for disease prevalence in any population; (c) estimate the post-test probability of disease in individual patients. Microsoft Excel(TM)was used. Section A: a contingency (2 x 2) table was incorporated into the spreadsheet. Formulae for standard calculations [sample size, disease prevalence, sensitivity and specificity with 95% confidence intervals, predictive values and likelihood ratios (LRs)] were linked to this table. The results change automatically when the data in the true or false negative and positive cells are changed. Section B: this estimates predictive values in any population, compensating for altered disease prevalence. Sections C-F: Bayes' theorem was incorporated to generate individual post-test probabilities. The spreadsheet generates 95% confidence intervals, LRs and a table and graph of conditional probabilities once the sensitivity and specificity of the test are entered. The latter shows the expected post-test probability of disease for any pre-test probability when a test of known sensitivity and specificity is positive or negative. This spreadsheet can be used on desktop and palmtop computers. The MS Excel(TM)version can be downloaded via the Internet from the URL ftp://radiography.com/pub/Rad-data99.xls A spreadsheet is useful for contingency table data analysis and assessment of the clinical meaning of diagnostic test results. Copyright 2000 The Royal College of Radiologists.

Effect of Accreditation on Accuracy of Diagnostic Tests in Medical Laboratories.

PubMed

Jang, Mi Ae; Yoon, Young Ahn; Song, Junghan; Kim, Jeong Ho; Min, Won Ki; Lee, Ji Sung; Lee, Yong Wha; Lee, You Kyoung

2017-05-01

Medical laboratories play a central role in health care. Many laboratories are taking a more focused and stringent approach to quality system management. In Korea, laboratory standardization efforts undertaken by the Korean Laboratory Accreditation Program (KLAP) and the Korean External Quality Assessment Scheme (KEQAS) may have facilitated an improvement in laboratory performance, but there are no fundamental studies demonstrating that laboratory standardization is effective. We analyzed the results of the KEQAS to identify significant differences between laboratories with or without KLAP and to determine the impact of laboratory standardization on the accuracy of diagnostic tests. We analyzed KEQAS participant data on clinical chemistry tests such as albumin, ALT, AST, and glucose from 2010 to 2013. As a statistical parameter to assess performance bias between laboratories, we compared 4-yr variance index score (VIS) between the two groups with or without KLAP. Compared with the group without KLAP, the group with KLAP exhibited significantly lower geometric means of 4-yr VIS for all clinical chemistry tests (P<0.0001); this difference justified a high level of confidence in standardized services provided by accredited laboratories. Confidence intervals for the mean of each test in the two groups (accredited and non-accredited) did not overlap, suggesting that the means of the groups are significantly different. These results confirmed that practice standardization is strongly associated with the accuracy of test results. Our study emphasizes the necessity of establishing a system for standardization of diagnostic testing. © The Korean Society for Laboratory Medicine

Effect of Accreditation on Accuracy of Diagnostic Tests in Medical Laboratories

PubMed Central

Jang, Mi-Ae; Yoon, Young Ahn; Song, Junghan; Kim, Jeong-Ho; Min, Won-Ki; Lee, Ji Sung

2017-01-01

Background Medical laboratories play a central role in health care. Many laboratories are taking a more focused and stringent approach to quality system management. In Korea, laboratory standardization efforts undertaken by the Korean Laboratory Accreditation Program (KLAP) and the Korean External Quality Assessment Scheme (KEQAS) may have facilitated an improvement in laboratory performance, but there are no fundamental studies demonstrating that laboratory standardization is effective. We analyzed the results of the KEQAS to identify significant differences between laboratories with or without KLAP and to determine the impact of laboratory standardization on the accuracy of diagnostic tests. Methods We analyzed KEQAS participant data on clinical chemistry tests such as albumin, ALT, AST, and glucose from 2010 to 2013. As a statistical parameter to assess performance bias between laboratories, we compared 4-yr variance index score (VIS) between the two groups with or without KLAP. Results Compared with the group without KLAP, the group with KLAP exhibited significantly lower geometric means of 4-yr VIS for all clinical chemistry tests (P<0.0001); this difference justified a high level of confidence in standardized services provided by accredited laboratories. Confidence intervals for the mean of each test in the two groups (accredited and non-accredited) did not overlap, suggesting that the means of the groups are significantly different. Conclusions These results confirmed that practice standardization is strongly associated with the accuracy of test results. Our study emphasizes the necessity of establishing a system for standardization of diagnostic testing. PMID:28224767

A diagnostic algorithm to optimize data collection and interpretation of Ripple Maps in atrial tachycardias.

PubMed

Koa-Wing, Michael; Nakagawa, Hiroshi; Luther, Vishal; Jamil-Copley, Shahnaz; Linton, Nick; Sandler, Belinda; Qureshi, Norman; Peters, Nicholas S; Davies, D Wyn; Francis, Darrel P; Jackman, Warren; Kanagaratnam, Prapa

2015-11-15

Ripple Mapping (RM) is designed to overcome the limitations of existing isochronal 3D mapping systems by representing the intracardiac electrogram as a dynamic bar on a surface bipolar voltage map that changes in height according to the electrogram voltage-time relationship, relative to a fiduciary point. We tested the hypothesis that standard approaches to atrial tachycardia CARTO™ activation maps were inadequate for RM creation and interpretation. From the results, we aimed to develop an algorithm to optimize RMs for future prospective testing on a clinical RM platform. CARTO-XP™ activation maps from atrial tachycardia ablations were reviewed by two blinded assessors on an off-line RM workstation. Ripple Maps were graded according to a diagnostic confidence scale (Grade I - high confidence with clear pattern of activation through to Grade IV - non-diagnostic). The RM-based diagnoses were corroborated against the clinical diagnoses. 43 RMs from 14 patients were classified as Grade I (5 [11.5%]); Grade II (17 [39.5%]); Grade III (9 [21%]) and Grade IV (12 [28%]). Causes of low gradings/errors included the following: insufficient chamber point density; window-of-interest<100% of cycle length (CL); <95% tachycardia CL mapped; variability of CL and/or unstable fiducial reference marker; and suboptimal bar height and scar settings. A data collection and map interpretation algorithm has been developed to optimize Ripple Maps in atrial tachycardias. This algorithm requires prospective testing on a real-time clinical platform. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

38 CFR 4.100 - Application of the evaluation criteria for diagnostic codes 7000-7007, 7011, and 7015-7020.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Ratings The Cardiovascular System § 4.100 Application of the evaluation criteria for diagnostic codes 7000... medical information does not sufficiently reflect the severity of the veteran's cardiovascular disability...

38 CFR 4.100 - Application of the evaluation criteria for diagnostic codes 7000-7007, 7011, and 7015-7020.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Ratings The Cardiovascular System § 4.100 Application of the evaluation criteria for diagnostic codes 7000... medical information does not sufficiently reflect the severity of the veteran's cardiovascular disability...

38 CFR 4.100 - Application of the evaluation criteria for diagnostic codes 7000-7007, 7011, and 7015-7020.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Ratings The Cardiovascular System § 4.100 Application of the evaluation criteria for diagnostic codes 7000... medical information does not sufficiently reflect the severity of the veteran's cardiovascular disability...

38 CFR 4.100 - Application of the evaluation criteria for diagnostic codes 7000-7007, 7011, and 7015-7020.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Ratings The Cardiovascular System § 4.100 Application of the evaluation criteria for diagnostic codes 7000... medical information does not sufficiently reflect the severity of the veteran's cardiovascular disability...

38 CFR 4.100 - Application of the evaluation criteria for diagnostic codes 7000-7007, 7011, and 7015-7020.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Ratings The Cardiovascular System § 4.100 Application of the evaluation criteria for diagnostic codes 7000... medical information does not sufficiently reflect the severity of the veteran's cardiovascular disability...

A readers' guide to the interpretation of diagnostic test properties: clinical example of sepsis.

PubMed

Fischer, Joachim E; Bachmann, Lucas M; Jaeschke, Roman

2003-07-01

One of the most challenging practical and daily problems in intensive care medicine is the interpretation of the results from diagnostic tests. In neonatology and pediatric intensive care the early diagnosis of potentially life-threatening infections is a particularly important issue. A plethora of tests have been suggested to improve diagnostic decision making in the clinical setting of infection which is a clinical example used in this article. Several criteria that are critical to evidence-based appraisal of published data are often not adhered to during the study or in reporting. To enhance the critical appraisal on articles on diagnostic tests we discuss various measures of test accuracy: sensitivity, specificity, receiver operating characteristic curves, positive and negative predictive values, likelihood ratios, pretest probability, posttest probability, and diagnostic odds ratio. We suggest the following minimal requirements for reporting on the diagnostic accuracy of tests: a plot of the raw data, multilevel likelihood ratios, the area under the receiver operating characteristic curve, and the cutoff yielding the highest discriminative ability. For critical appraisal it is mandatory to report confidence intervals for each of these measures. Moreover, to allow comparison to the readers' patient population authors should provide data on study population characteristics, in particular on the spectrum of diseases and illness severity.

The Diagnostic Value of Gastrin-17 Detection in Atrophic Gastritis

PubMed Central

Wang, Xu; Ling, Li; Li, Shanshan; Qin, Guiping; Cui, Wei; Li, Xiang; Ni, Hong

2016-01-01

Abstract A meta-analysis was performed to assess the diagnostic value of gastrin-17 (G-17) for the early detection of chronic atrophic gastritis (CAG). An extensive literature search was performed, with the aim of selecting publications that reported the accuracy of G-17 in predicting CAG, in the following databases: PubMed, Science Direct, Web of Science, Chinese Biological Medicine, Chinese National Knowledge Infrastructure, Wanfang, and VIP. To assess the diagnostic value of G-17, the following statistics were estimated and described: sensitivity, specificity, diagnostic odds ratios (DOR), summary receiver operating characteristic curves, area under the curve (AUC), and 95% confidence intervals (CIs). Thirteen studies that met the inclusion criteria were included in this meta-analysis, comprising 894 patients and 1950 controls. The pooled sensitivity and specificity of these studies were 0.48 (95% CI: 0.45–0.51) and 0.79 (95% CI: 0.77–0.81), respectively. The DOR was 5.93 (95% CI: 2.93–11.99), and the AUC was 0.82. G-17 may have potential diagnostic value because it has good specificity and a moderate DOR and AUC for CAG. However, more studies are needed to improve the sensitivity of this diagnostic tool in the future. PMID:27149493

Diagnosis and classification of mastocytosis in non-specialized versus reference centres: a Spanish Network on Mastocytosis (REMA) study on 122 patients.

PubMed

Sánchez-Muñoz, Laura; Morgado, Jose M; Álvarez-Twose, Ivan; Matito, Almudena; Garcia-Montero, Andrés C; Teodosio, Cristina; Jara-Acevedo, Maria; Mayado, Andrea; Mollejo, Manuela; Caldas, Carolina; González de Olano, David; Escribano, Luis; Orfao, Alberto

2016-01-01

The diagnosis of 'rare diseases', such as mastocytosis, remains a challenge. Despite this, the precise benefits of referral of mastocytosis patients to highly specialized reference centres are poorly defined and whether patients should be managed at non-specialized versus reference centres remains a matter of debate. To evaluate the quality and efficiency of diagnostic procedures performed at the reference centres for mastocytosis in Spain (REMA) versus other non-reference centres, we retrospectively analysed a series of 122 patients, for the overall degree of agreement obtained for the World Health Organization (WHO) diagnostic and classification criteria betwen the referring and REMA centres. Our results showed that not all WHO diagnostic criteria were frequently investigated at the referring centres. Among the five WHO diagnostic criteria, the highest degree of agreement was obtained for serum tryptase levels [median 90% (95% confidence interval 84-96%)]; in turn, the overall agreement was significantly lower for the major histopathological criterion [80% (72-89%)], and the other three minor criteria: cytomorphology [68% (56-80%)] immunophenotyping of BM mast cells [75% (62-87%)] and detection of the KIT mutation [34% (8-60%)]. Referral of patients with diagnostic suspicion of mastocytosis to a multidisciplinary reference centre improves diagnostic efficiency and quality. © 2015 John Wiley & Sons Ltd.

Mean cerebral blood volume is an effective diagnostic index of recurrent and radiation injury in glioma patients: A meta-analysis of diagnostic test.

PubMed

Li, Zhanzhan; Zhou, Qin; Li, Yanyan; Yan, Shipeng; Fu, Jun; Huang, Xinqiong; Shen, Liangfang

2017-02-28

We conducted a meta-analysis to evaluate the diagnostic values of mean cerebral blood volume for recurrent and radiation injury in glioma patients. We performed systematic electronic searches for eligible study up to August 8, 2016. Bivariate mixed effects models were used to estimate the combined sensitivity, specificity, positive likelihood ratios, negative likelihood ratios, diagnostic odds ratios and their 95% confidence intervals (CIs). Fifteen studies with a total number of 576 participants were enrolled. The pooled sensitivity and specificity of diagnostic were 0.88 (95%CI: 0.82-0.92) and 0.85 (95%CI: 0.68-0.93). The pooled positive likelihood ratio is 5.73 (95%CI: 2.56-12.81), negative likelihood ratio is 0.15 (95%CI: 0.10-0.22), and the diagnostic odds ratio is 39.34 (95%CI:13.96-110.84). The summary receiver operator characteristic is 0.91 (95%CI: 0.88-0.93). However, the Deek's plot suggested publication bias may exist (t=2.30, P=0.039). Mean cerebral blood volume measurement methods seems to be very sensitive and highly specific to differentiate recurrent and radiation injury in glioma patients. The results should be interpreted with caution because of the potential bias.

Recent advances in low-cost microfluidic platforms for diagnostic applications.

PubMed

Tomazelli Coltro, Wendell Karlos; Cheng, Chao-Min; Carrilho, Emanuel; de Jesus, Dosil Pereira

2014-08-01

The use of inexpensive materials and cost-effective manufacturing processes for mass production of microfluidic devices is very attractive and has spurred a variety of approaches. Such devices are particularly suited for diagnostic applications in limited resource settings. This review describes the recent and remarkable advances in the use of low-cost substrates for the development of microfluidic devices for diagnostics and clinical assays. Thus, a plethora of new and improved fabrication methods, designs, capabilities, detections, and applications of microfluidic devices fabricated with paper, plastic, and threads are covered. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[THE VIRTUAL CYTOLOGIC SLIDES FOR EXTERNAL EVALUATION OF QUALITY OF IMPLEMENTATION OF CYTOLOGIC ANALYSES IN CLINICAL DIAGNOSTIC LABORATORIES: POSSIBILITIES AND PERSPECTIVES].

PubMed

Djangirova, T V; Shabalova, I P; Pronichev, A N; Polyakov, E V

2015-08-01

The article considers application of technology of analysis of cytological slides in external quality control of clinical diagnostic laboratories. The advantages of virtual slides are demonstrated against other applied technologies of external evaluation of quality i.e. slide plate and digital micro-photography. The conditions of formation of virtual slides for external evaluation of quality of clinical diagnostic laboratories. The technology of their application is described. The success of practical application of considered technology in the Federal system of external evaluation of quality is emphasized.

Nucleic acid probes in diagnostic medicine

NASA Technical Reports Server (NTRS)

Oberry, Phillip A.

1991-01-01

The need for improved diagnostic procedures is outlined and variations in probe technology are briefly reviewed. A discussion of the application of probe technology to the diagnosis of disease in animals and humans is presented. A comparison of probe versus nonprobe diagnostics and isotopic versus nonisotopic probes is made and the current state of sequence amplification is described. The current market status of nucleic acid probes is reviewed with respect to their diagnostic application in human and veterinary medicine. Representative product examples are described and information on probes being developed that offer promise as future products is discussed.

Adverse Outcome Pathways for Regulatory Applications: Examination of Four Case Studies With Different Degrees of Completeness and Scientific Confidence.

PubMed

Perkins, Edward J; Antczak, Philipp; Burgoon, Lyle; Falciani, Francesco; Garcia-Reyero, Natàlia; Gutsell, Steve; Hodges, Geoff; Kienzler, Aude; Knapen, Dries; McBride, Mary; Willett, Catherine

2015-11-01

Adverse outcome pathways (AOPs) offer a pathway-based toxicological framework to support hazard assessment and regulatory decision-making. However, little has been discussed about the scientific confidence needed, or how complete a pathway should be, before use in a specific regulatory application. Here we review four case studies to explore the degree of scientific confidence and extent of completeness (in terms of causal events) that is required for an AOP to be useful for a specific purpose in a regulatory application: (i) Membrane disruption (Narcosis) leading to respiratory failure (low confidence), (ii) Hepatocellular proliferation leading to cancer (partial pathway, moderate confidence), (iii) Covalent binding to proteins leading to skin sensitization (high confidence), and (iv) Aromatase inhibition leading to reproductive dysfunction in fish (high confidence). Partially complete AOPs with unknown molecular initiating events, such as 'Hepatocellular proliferation leading to cancer', were found to be valuable. We demonstrate that scientific confidence in these pathways can be increased though the use of unconventional information (eg, computational identification of potential initiators). AOPs at all levels of confidence can contribute to specific uses. A significant statistical or quantitative relationship between events and/or the adverse outcome relationships is a common characteristic of AOPs, both incomplete and complete, that have specific regulatory uses. For AOPs to be useful in a regulatory context they must be at least as useful as the tools that regulators currently possess, or the techniques currently employed by regulators. Published by Oxford University Press on behalf of the Society of Toxicology 2015. This work is written by US Government employees and is in the public domain in the US.

Bayesian tomography and integrated data analysis in fusion diagnostics

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

Li, Dong, E-mail: lid@swip.ac.cn; Dong, Y. B.; Deng, Wei

2016-11-15

In this article, a Bayesian tomography method using non-stationary Gaussian process for a prior has been introduced. The Bayesian formalism allows quantities which bear uncertainty to be expressed in the probabilistic form so that the uncertainty of a final solution can be fully resolved from the confidence interval of a posterior probability. Moreover, a consistency check of that solution can be performed by checking whether the misfits between predicted and measured data are reasonably within an assumed data error. In particular, the accuracy of reconstructions is significantly improved by using the non-stationary Gaussian process that can adapt to the varyingmore » smoothness of emission distribution. The implementation of this method to a soft X-ray diagnostics on HL-2A has been used to explore relevant physics in equilibrium and MHD instability modes. This project is carried out within a large size inference framework, aiming at an integrated analysis of heterogeneous diagnostics.« less

The STARD statement for reporting diagnostic accuracy studies: application to the history and physical examination.

PubMed

Simel, David L; Rennie, Drummond; Bossuyt, Patrick M M

2008-06-01

The Standards for Reporting of Diagnostic Accuracy (STARD) statement provided guidelines for investigators conducting diagnostic accuracy studies. We reviewed each item in the statement for its applicability to clinical examination diagnostic accuracy research, viewing each discrete aspect of the history and physical examination as a diagnostic test. Nonsystematic review of the STARD statement. Two former STARD Group participants and 1 editor of a journal series on clinical examination research reviewed each STARD item. Suggested interpretations and comments were shared to develop consensus. The STARD Statement applies generally well to clinical examination diagnostic accuracy studies. Three items are the most important for clinical examination diagnostic accuracy studies, and investigators should pay particular attention to their requirements: describe carefully the patient recruitment process, describe participant sampling and address if patients were from a consecutive series, and describe whether the clinicians were masked to the reference standard tests and whether the interpretation of the reference standard test was masked to the clinical examination components or overall clinical impression. The consideration of these and the other STARD items in clinical examination diagnostic research studies would improve the quality of investigations and strengthen conclusions reached by practicing clinicians. The STARD statement provides a very useful framework for diagnostic accuracy studies. The group correctly anticipated that there would be nuances applicable to studies of the clinical examination. We offer guidance that should enhance their usefulness to investigators embarking on original studies of a patient's history and physical examination.

Online Learning and Teacher Education: Knowledge Acquisition, Application Skills, and Reported Confidence

ERIC Educational Resources Information Center

IRIS Center, 2014

2014-01-01

This report presents two studies that demonstrate superior performance of college students after use of free, online instructional Modules, produced by the IRIS Center. When compared to traditional teacher education methods, IRIS Modules yield better outcomes in terms of knowledge acquisition, application skills, and confidence in the use of…

Pulmonary disease in cystic fibrosis: assessment with chest CT at chest radiography dose levels.

PubMed

Ernst, Caroline W; Basten, Ines A; Ilsen, Bart; Buls, Nico; Van Gompel, Gert; De Wachter, Elke; Nieboer, Koenraad H; Verhelle, Filip; Malfroot, Anne; Coomans, Danny; De Maeseneer, Michel; de Mey, Johan

2014-11-01

To investigate a computed tomographic (CT) protocol with iterative reconstruction at conventional radiography dose levels for the assessment of structural lung abnormalities in patients with cystic fibrosis ( CF cystic fibrosis ). In this institutional review board-approved study, 38 patients with CF cystic fibrosis (age range, 6-58 years; 21 patients <18 years and 17 patients >18 years) underwent investigative CT (at minimal exposure settings combined with iterative reconstruction) as a replacement of yearly follow-up posteroanterior chest radiography. Verbal informed consent was obtained from all patients or their parents. CT images were randomized and rated independently by two radiologists with use of the Bhalla scoring system. In addition, mosaic perfusion was evaluated. As reference, the previous available conventional chest CT scan was used. Differences in Bhalla scores were assessed with the χ(2) test and intraclass correlation coefficients ( ICC intraclass correlation coefficient s). Radiation doses for CT and radiography were assessed for adults (>18 years) and children (<18 years) separately by using technical dose descriptors and estimated effective dose. Differences in dose were assessed with the Mann-Whitney U test. The median effective dose for the investigative protocol was 0.04 mSv (95% confidence interval [ CI confidence interval ]: 0.034 mSv, 0.10 mSv) for children and 0.05 mSv (95% CI confidence interval : 0.04 mSv, 0.08 mSv) for adults. These doses were much lower than those with conventional CT (median: 0.52 mSv [95% CI confidence interval : 0.31 mSv, 3.90 mSv] for children and 1.12 mSv [95% CI confidence interval : 0.57 mSv, 3.15 mSv] for adults) and of the same order of magnitude as those for conventional radiography (median: 0.012 mSv [95% CI confidence interval : 0.006 mSv, 0.022 mSv] for children and 0.012 mSv [95% CI confidence interval : 0.005 mSv, 0.031 mSv] for adults). All images were rated at least as diagnostically acceptable. Very good agreement was found in overall Bhalla score ( ICC intraclass correlation coefficient , 0.96) with regard to the severity of bronchiectasis ( ICC intraclass correlation coefficient , 0.87) and sacculations and abscesses ( ICC intraclass correlation coefficient , 0.84). Interobserver agreement was excellent ( ICC intraclass correlation coefficient , 0.86-1). For patients with CF cystic fibrosis , a dedicated chest CT protocol can replace the two yearly follow-up chest radiographic examinations without major dose penalty and with similar diagnostic quality compared with conventional CT.

Optical diagnostics in the oral cavity: an overview.

PubMed

Wilder-Smith, P; Holtzman, J; Epstein, J; Le, A

2010-11-01

As the emphasis shifts from damage mitigation to disease prevention or reversal of early disease in the oral cavity, the need for sensitive and accurate detection and diagnostic tools become more important. Many novel and emergent optical diagnostic modalities for the oral cavity are becoming available to clinicians with a variety of desirable attributes including: (i) non-invasiveness, (ii) absence of ionizing radiation, (iii) patient-friendliness, (iv) real-time information (v) repeatability, and (vi) high-resolution surface and subsurface images. In this article, the principles behind optical diagnostic approaches, their feasibility and applicability for imaging soft and hard tissues, and their potential usefulness as a tool in the diagnosis of oral mucosal lesions, dental pathologies, and other dental applications will be reviewed. The clinical applications of light-based imaging technologies in the oral cavity and of their derivative devices will be discussed to provide the reader with a comprehensive understanding of emergent diagnostic modalities. © 2010 John Wiley & Sons A/S.

Smartphones, tablets and mobile applications for radiology.

PubMed

Székely, András; Talanow, Roland; Bágyi, Péter

2013-05-01

Smartphones are phone devices that may also be used for browsing, navigation and running smaller computer programs called applications. One may consider them as compact personal computers which are primarily to be used for making phone calls. Tablets or "tablet PCs" are fully functioning standalone computers the size of a thin LCD monitor that use the screen itself for control and data input. Both of these devices may be categorized based on the mobile operating system that they use. The aim of this study is to illustrate how smartphones and tablets can be used by diagnostic imaging professionals, radiographers and residents, and to introduce relevant applications that are available for their field. A search was performed on iTunes, Android Market, Blackberry App World, and Windows Phone Marketplace for mobile applications pertinent to the field of diagnostic imaging. The following terms were applied for the search strategy: (1) radiology, (2) X-ray, (3) ultrasound, (4) MRI, (5) CT, (6) radiographer, (7) nuclear medicine. Two radiologists and one radiology resident reviewed the results. Our review was limited to english-language software. Additional applications were identified by reviewing the list of similar software provided in the description of each application. We downloaded and installed all applications that appeared relevant to an appropriate mobile phone or tablet device. We identified and reviewed a total of 102 applications. We ruled out 1 non-English application and 20 other applications that were created for entertainment purposes. Thus our final list includes 81 applications in the following five categories: diagnostic reading, decision support applications, medical books, interactive encyclopedias, and journal reading programs. Smartphones and tablets offer new opportunities for diagnostic imaging practitioners; these easy-to-use devices equipped with excellent display may be used for diagnostic reading, reference, learning, consultation, and for communication with patients. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Experimental Validation Plan for the Xolotl Plasma-Facing Component Simulator Using Tokamak Sample Exposures

NASA Astrophysics Data System (ADS)

Chan, V. S.; Wong, C. P. C.; McLean, A. G.; Luo, G. N.; Wirth, B. D.

2013-10-01

The Xolotl code under development by PSI-SciDAC will enhance predictive modeling capability of plasma-facing materials under burning plasma conditions. The availability and application of experimental data to compare to code-calculated observables are key requirements to validate the breadth and content of physics included in the model and ultimately gain confidence in its results. A dedicated effort has been in progress to collect and organize a) a database of relevant experiments and their publications as previously carried out at sample exposure facilities in US and Asian tokamaks (e.g., DIII-D DiMES, and EAST MAPES), b) diagnostic and surface analysis capabilities available at each device, and c) requirements for future experiments with code validation in mind. The content of this evolving database will serve as a significant resource for the plasma-material interaction (PMI) community. Work supported in part by the US Department of Energy under GA-DE-SC0008698, DE-AC52-07NA27344 and DE-AC05-00OR22725.

Performance of uncertainty quantification methodologies and linear solvers in cardiovascular simulations

NASA Astrophysics Data System (ADS)

Seo, Jongmin; Schiavazzi, Daniele; Marsden, Alison

2017-11-01

Cardiovascular simulations are increasingly used in clinical decision making, surgical planning, and disease diagnostics. Patient-specific modeling and simulation typically proceeds through a pipeline from anatomic model construction using medical image data to blood flow simulation and analysis. To provide confidence intervals on simulation predictions, we use an uncertainty quantification (UQ) framework to analyze the effects of numerous uncertainties that stem from clinical data acquisition, modeling, material properties, and boundary condition selection. However, UQ poses a computational challenge requiring multiple evaluations of the Navier-Stokes equations in complex 3-D models. To achieve efficiency in UQ problems with many function evaluations, we implement and compare a range of iterative linear solver and preconditioning techniques in our flow solver. We then discuss applications to patient-specific cardiovascular simulation and how the problem/boundary condition formulation in the solver affects the selection of the most efficient linear solver. Finally, we discuss performance improvements in the context of uncertainty propagation. Support from National Institute of Health (R01 EB018302) is greatly appreciated.

Integrated diagnostics

NASA Technical Reports Server (NTRS)

Hunthausen, Roger J.

1988-01-01

Recently completed projects in which advanced diagnostic concepts were explored and/or demonstrated are summarized. The projects begin with the design of integrated diagnostics for the Army's new gas turbine engines, and advance to the application of integrated diagnostics to other aircraft subsystems. Finally, a recent project is discussed which ties together subsystem fault monitoring and diagnostics with a more complete picture of flight domain knowledge.

A Review of Diagnostic Techniques for ISHM Applications

NASA Technical Reports Server (NTRS)

Patterson-Hine, Ann; Biswas, Gautam; Aaseng, Gordon; Narasimhan, Sriam; Pattipati, Krishna

2005-01-01

System diagnosis is an integral part of any Integrated System Health Management application. Diagnostic applications make use of system information from the design phase, such as safety and mission assurance analysis, failure modes and effects analysis, hazards analysis, functional models, fault propagation models, and testability analysis. In modern process control and equipment monitoring systems, topological and analytic , models of the nominal system, derived from design documents, are also employed for fault isolation and identification. Depending on the complexity of the monitored signals from the physical system, diagnostic applications may involve straightforward trending and feature extraction techniques to retrieve the parameters of importance from the sensor streams. They also may involve very complex analysis routines, such as signal processing, learning or classification methods to derive the parameters of importance to diagnosis. The process that is used to diagnose anomalous conditions from monitored system signals varies widely across the different approaches to system diagnosis. Rule-based expert systems, case-based reasoning systems, model-based reasoning systems, learning systems, and probabilistic reasoning systems are examples of the many diverse approaches ta diagnostic reasoning. Many engineering disciplines have specific approaches to modeling, monitoring and diagnosing anomalous conditions. Therefore, there is no "one-size-fits-all" approach to building diagnostic and health monitoring capabilities for a system. For instance, the conventional approaches to diagnosing failures in rotorcraft applications are very different from those used in communications systems. Further, online and offline automated diagnostic applications are integrated into an operations framework with flight crews, flight controllers and maintenance teams. While the emphasis of this paper is automation of health management functions, striking the correct balance between automated and human-performed tasks is a vital concern.

Whole Genome Sequencing Increases Molecular Diagnostic Yield Compared with Current Diagnostic Testing for Inherited Retinal Disease.

PubMed

Ellingford, Jamie M; Barton, Stephanie; Bhaskar, Sanjeev; Williams, Simon G; Sergouniotis, Panagiotis I; O'Sullivan, James; Lamb, Janine A; Perveen, Rahat; Hall, Georgina; Newman, William G; Bishop, Paul N; Roberts, Stephen A; Leach, Rick; Tearle, Rick; Bayliss, Stuart; Ramsden, Simon C; Nemeth, Andrea H; Black, Graeme C M

2016-05-01

To compare the efficacy of whole genome sequencing (WGS) with targeted next-generation sequencing (NGS) in the diagnosis of inherited retinal disease (IRD). Case series. A total of 562 patients diagnosed with IRD. We performed a direct comparative analysis of current molecular diagnostics with WGS. We retrospectively reviewed the findings from a diagnostic NGS DNA test for 562 patients with IRD. A subset of 46 of 562 patients (encompassing potential clinical outcomes of diagnostic analysis) also underwent WGS, and we compared mutation detection rates and molecular diagnostic yields. In addition, we compared the sensitivity and specificity of the 2 techniques to identify known single nucleotide variants (SNVs) using 6 control samples with publically available genotype data. Diagnostic yield of genomic testing. Across known disease-causing genes, targeted NGS and WGS achieved similar levels of sensitivity and specificity for SNV detection. However, WGS also identified 14 clinically relevant genetic variants through WGS that had not been identified by NGS diagnostic testing for the 46 individuals with IRD. These variants included large deletions and variants in noncoding regions of the genome. Identification of these variants confirmed a molecular diagnosis of IRD for 11 of the 33 individuals referred for WGS who had not obtained a molecular diagnosis through targeted NGS testing. Weighted estimates, accounting for population structure, suggest that WGS methods could result in an overall 29% (95% confidence interval, 15-45) uplift in diagnostic yield. We show that WGS methods can detect disease-causing genetic variants missed by current NGS diagnostic methodologies for IRD and thereby demonstrate the clinical utility and additional value of WGS. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

The Use of Standardized Test Batteries in Assessing the Skill Development of Children with Mild-to-Moderate Sensorineural Hearing Loss.

ERIC Educational Resources Information Center

Plapinger, Donald S.; Sikora, Darryn M.

1995-01-01

This study of 12 children (ages 7-13) with mild to moderate bilateral sensorineural hearing loss found that psychoeducational diagnostic tests standardized on students with normal hearing may be used with confidence to assess both cognitive and academic levels of functioning in students with sensorineural hearing loss. (Author/JDD)

An international comparative family medicine study of the Transition Project data from the Netherlands, Malta and Serbia. Is family medicine an international discipline? Comparing diagnostic odds ratios across populations.

PubMed

Soler, Jean K; Okkes, Inge; Oskam, Sibo; van Boven, Kees; Zivotic, Predrag; Jevtic, Milan; Dobbs, Frank; Lamberts, Henk

2012-06-01

This is an international study of the epidemiology of family medicine (FM) in three practice populations from the Netherlands, Malta and Serbia. Diagnostic associations between common reasons for encounter (RfEs) and episodes titles are compared and similarities and differences are described and analysed. Participating family doctors (FDs) recorded details of all their patient contacts in an 'episode of care (EoC)' structure using the International Classification of Primary Care (ICPC). RfEs presented by the patient and episode titles (diagnostic labels of EoCs) were classified with ICPC. The relationships between RfEs and episode titles were studied with Bayesian methods. Distributions of diagnostic odds ratios (ORs) from the three population databases are presented and compared. ICPC, the RfE and the EoC data model are appropriate tools to study the process of diagnosis in FM. Distributions of diagnostic associations between RfEs and episode titles in the Transition Project international populations show remarkable similarities and congruencies in the process of diagnosis from both the RfE and the episode title perspectives. The congruence of diagnostic associations between populations supports the use of such data from one population to inform diagnostic decisions in another. Differences in the magnitude of such diagnostic associations are significant, and population-specific data are therefore desirable. We propose that both an international (common) and a local (health care system specific) content of FM exist and that the empirical distributions of diagnostic associations presented in this paper are a reflection of both these effects. We also observed that the frequency of exposure to such diagnostic challenges had a strong effect on the confidence intervals of diagnostic ORs reflecting these diagnostic associations. We propose that this constitutes evidence that expertise in FM is associated with frequency of exposure to diagnostic challenges.

En Route to the Clinic: Diagnostic Sequencing Applications Using the Ion Torrent (7th Annual SFAF Meeting, 2012)

ScienceCinema

Muzny, Donna

2018-01-15

Donna Muzny on "En route to the clinic: Diagnostic sequencing applications using the Ion Torrent" at the 2012 Sequencing, Finishing, Analysis in the Future Meeting held June 5-7, 2012 in Santa Fe, New Mexico.

Chemical Structure and Surface Modification of Dendritic Nanomaterials Tailored for Therapeutic and Diagnostic Applications.

PubMed

Myung, Ja Hye; Hsu, Hao-Jui; Bugno, Jason; Tam, Kevin A; Hong, Seungpyo

2017-01-01

Dendritic nanomaterials have attracted a great deal of scientific interest due to their high capacity for multifunctionalization and potential in various biomedical applications, such as drug/gene delivery and diagnostic systems. Depending on the molecular structure and starting monomers, several different types of dendrimers have been developed, including poly(amidoamine) (PAMAM), poly(propylenimine) (PPI), and poly(L-lysine) (PLL) dendrimers, in addition to modified dendritic nanomaterials, such as Janus dendrimers and dendritic block copolymers. The chemical structure and surface modification of dendritic nanomaterials have been found to play a critical role in governing their biological behaviors. In this review, we present a comprehensive overview focusing on the synthesis and chemical structures of dendrimers and modified dendritic nanomaterials that are currently being investigated for drug delivery, gene delivery, and diagnostic applications. In addition, the impact of chemical surface modification and functionalization to the dendritic nanomaterials on their therapeutic and diagnostic applications are highlighted. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

A Brief Overview of Tauopathy: Causes, Consequences, and Therapeutic Strategies.

PubMed

Orr, Miranda E; Sullivan, A Campbell; Frost, Bess

2017-07-01

There are currently no disease-modifying therapies for the treatment of tauopathies, a group of progressive neurodegenerative disorders that are pathologically defined by the presence of tau protein aggregates in the brain. Current challenges for the treatment of tauopathies include the inability to diagnose early and to confidently discriminate between distinct tauopathies in patients, alongside an incomplete understanding of the cellular mechanisms involved in pathogenic tau-induced neuronal death and dysfunction. In this review, we describe current diagnostic and therapeutic strategies, known drivers of pathogenic tau formation, recent contributions to our current mechanistic understanding of how pathogenic tau induces neuronal death, and potential diagnostic and therapeutic approaches. Copyright © 2017 Elsevier Ltd. All rights reserved.

Generalized likelihood ratios for quantitative diagnostic test scores.

PubMed

Tandberg, D; Deely, J J; O'Malley, A J

1997-11-01

The reduction of quantitative diagnostic test scores to the dichotomous case is a wasteful and unnecessary simplification in the era of high-speed computing. Physicians could make better use of the information embedded in quantitative test results if modern generalized curve estimation techniques were applied to the likelihood functions of Bayes' theorem. Hand calculations could be completely avoided and computed graphical summaries provided instead. Graphs showing posttest probability of disease as a function of pretest probability with confidence intervals (POD plots) would enhance acceptance of these techniques if they were immediately available at the computer terminal when test results were retrieved. Such constructs would also provide immediate feedback to physicians when a valueless test had been ordered.

Mixed group validation: a method to address the limitations of criterion group validation in research on malingering detection.

PubMed

Frederick, R I

2000-01-01

Mixed group validation (MGV) is offered as an alternative to criterion group validation (CGV) to estimate the true positive and false positive rates of tests and other diagnostic signs. CGV requires perfect confidence about each research participant's status with respect to the presence or absence of pathology. MGV determines diagnostic efficiencies based on group data; knowing an individual's status with respect to pathology is not required. MGV can use relatively weak indicators to validate better diagnostic signs, whereas CGV requires perfect diagnostic signs to avoid error in computing true positive and false positive rates. The process of MGV is explained, and a computer simulation demonstrates the soundness of the procedure. MGV of the Rey 15-Item Memory Test (Rey, 1958) for 723 pre-trial criminal defendants resulted in higher estimates of true positive rates and lower estimates of false positive rates as compared with prior research conducted with CGV. The author demonstrates how MGV addresses all the criticisms Rogers (1997b) outlined for differential prevalence designs in malingering detection research. Copyright 2000 John Wiley & Sons, Ltd.

Deletion Diagnostics for Alternating Logistic Regressions

PubMed Central

Preisser, John S.; By, Kunthel; Perin, Jamie; Qaqish, Bahjat F.

2013-01-01

Deletion diagnostics are introduced for the regression analysis of clustered binary outcomes estimated with alternating logistic regressions, an implementation of generalized estimating equations (GEE) that estimates regression coefficients in a marginal mean model and in a model for the intracluster association given by the log odds ratio. The diagnostics are developed within an estimating equations framework that recasts the estimating functions for association parameters based upon conditional residuals into equivalent functions based upon marginal residuals. Extensions of earlier work on GEE diagnostics follow directly, including computational formulae for one-step deletion diagnostics that measure the influence of a cluster of observations on the estimated regression parameters and on the overall marginal mean or association model fit. The diagnostic formulae are evaluated with simulations studies and with an application concerning an assessment of factors associated with health maintenance visits in primary care medical practices. The application and the simulations demonstrate that the proposed cluster-deletion diagnostics for alternating logistic regressions are good approximations of their exact fully iterated counterparts. PMID:22777960

Establishing confidence in CCV/ACT technology

NASA Technical Reports Server (NTRS)

Holloway, R. B.; Shomber, H. A.

1976-01-01

Despite significant advancements in controls configured vehicles/active controls technology (CCV/ACT) in the past decade, few applications of this promising technology have appeared in recent aircraft designs. The status of CCV/ACT is summarized, and some of the constraints which are retarding its wider application are described. Suggestions toward establishing an increased level of confidence in the technology are given.

Applications of the oral scraped (exfoliative) cytology in oral cancer and precancer.

PubMed

Acha, Amelia; Ruesga, María T; Rodríguez, María J; Martínez de Pancorbo, María A; Aguirre, José M

2005-01-01

Scraped (exfoliative) cytology is a simple and harmless procedure, which has been a controversial technique according to its real validity in oral pathology. Lately it has re-emerged due to its application in oral precancer and cancer as a diagnostic and predictive method as well as for monitoring patients. New diagnostic techniques have been developed, such as "brush biopsy" and multiple molecular studies using the cells collected. In this review we are going to analyse the more novel aspects related with the applications of the scraped or exfoliative cytology in oral precancerous and cancerous pathology, specially focusing on molecular studies and their diagnostic and prognostic implications.

A semi-automated, field-portable microscopy platform for clinical diagnostic applications

NASA Astrophysics Data System (ADS)

Jagannadh, Veerendra Kalyan; Srinivasan, Rajesh; Gorthi, Sai Siva

2015-08-01

Clinical microscopy is a versatile diagnostic platform used for diagnosis of a multitude of diseases. In the recent past, many microfluidics based point-of-care diagnostic devices have been developed, which serve as alternatives to microscopy. However, these point-of-care devices are not as multi-functional and versatile as clinical microscopy. With the use of custom designed optics and microfluidics, we have developed a versatile microscopy-based cellular diagnostic platform, which can be used at the point of care. The microscopy platform presented here is capable of detecting infections of very low parasitemia level (in a very small quantity of sample), without the use of any additional computational hardware. Such a cost-effective and portable diagnostic device, would greatly impact the quality of health care available to people living in rural locations of the world. Apart from clinical diagnostics, it's applicability to field research in environmental microbiology has also been outlined.

A multispectral imaging approach for diagnostics of skin pathologies

NASA Astrophysics Data System (ADS)

Lihacova, Ilze; Derjabo, Aleksandrs; Spigulis, Janis

2013-06-01

Noninvasive multispectral imaging method was applied for different skin pathology such as nevus, basal cell carcinoma, and melanoma diagnostics. Developed melanoma diagnostic parameter, using three spectral bands (540 nm, 650 nm and 950 nm), was calculated for nevus, melanoma and basal cell carcinoma. Simple multispectral diagnostic device was established and applied for skin assessment. Development and application of multispectral diagnostics method described further in this article.

Faultfinder: A diagnostic expert system with graceful degradation for onboard aircraft applications

NASA Technical Reports Server (NTRS)

Abbott, Kathy H.; Schutte, Paul C.; Palmer, Michael T.; Ricks, Wendell R.

1988-01-01

A research effort was conducted to explore the application of artificial intelligence technology to automation of fault monitoring and diagnosis as an aid to the flight crew. Human diagnostic reasoning was analyzed and actual accident and incident cases were reconstructed. Based on this analysis and reconstruction, diagnostic concepts were conceived and implemented for an aircraft's engine and hydraulic subsystems. These concepts are embedded within a multistage approach to diagnosis that reasons about time-based, causal, and qualitative information, and enables a certain amount of graceful degradation. The diagnostic concepts are implemented in a computer program called Faultfinder that serves as a research prototype.

The application of high-speed photography in z-pinch high-temperature plasma diagnostics

NASA Astrophysics Data System (ADS)

Wang, Kui-lu; Qiu, Meng-tong; Hei, Dong-wei

2007-01-01

This invited paper is presented to discuss the application of high speed photography in z-pinch high temperature plasma diagnostics in recent years in Northwest Institute of Nuclear Technology in concentrative mode. The developments and applications of soft x-ray framing camera, soft x-ray curved crystal spectrometer, optical framing camera, ultraviolet four-frame framing camera and ultraviolet-visible spectrometer are introduced.

Six-minute magnetic resonance imaging protocol for evaluation of acute ischemic stroke: pushing the boundaries.

PubMed

Nael, Kambiz; Khan, Rihan; Choudhary, Gagandeep; Meshksar, Arash; Villablanca, Pablo; Tay, Jennifer; Drake, Kendra; Coull, Bruce M; Kidwell, Chelsea S

2014-07-01

If magnetic resonance imaging (MRI) is to compete with computed tomography for evaluation of patients with acute ischemic stroke, there is a need for further improvements in acquisition speed. Inclusion criteria for this prospective, single institutional study were symptoms of acute ischemic stroke within 24 hours onset, National Institutes of Health Stroke Scale ≥3, and absence of MRI contraindications. A combination of echo-planar imaging (EPI) and a parallel acquisition technique were used on a 3T magnetic resonance (MR) scanner to accelerate the acquisition time. Image analysis was performed independently by 2 neuroradiologists. A total of 62 patients met inclusion criteria. A repeat MRI scan was performed in 22 patients resulting in a total of 84 MRIs available for analysis. Diagnostic image quality was achieved in 100% of diffusion-weighted imaging, 100% EPI-fluid attenuation inversion recovery imaging, 98% EPI-gradient recalled echo, 90% neck MR angiography and 96% of brain MR angiography, and 94% of dynamic susceptibility contrast perfusion scans with interobserver agreements (k) ranging from 0.64 to 0.84. Fifty-nine patients (95%) had acute infarction. There was good interobserver agreement for EPI-fluid attenuation inversion recovery imaging findings (k=0.78; 95% confidence interval, 0.66-0.87) and for detection of mismatch classification using dynamic susceptibility contrast-Tmax (k=0.92; 95% confidence interval, 0.87-0.94). Thirteen acute intracranial hemorrhages were detected on EPI-gradient recalled echo by both observers. A total of 68 and 72 segmental arterial stenoses were detected on contrast-enhanced MR angiography of the neck and brain with k=0.93, 95% confidence interval, 0.84 to 0.96 and 0.87, 95% confidence interval, 0.80 to 0.90, respectively. A 6-minute multimodal MR protocol with good diagnostic quality is feasible for the evaluation of patients with acute ischemic stroke and can result in significant reduction in scan time rivaling that of the multimodal computed tomographic protocol. © 2014 American Heart Association, Inc.

The STARD Statement for Reporting Diagnostic Accuracy Studies: Application to the History and Physical Examination

PubMed Central

Rennie, Drummond; Bossuyt, Patrick M. M.

2008-01-01

Summary Objective The Standards for Reporting of Diagnostic Accuracy (STARD) statement provided guidelines for investigators conducting diagnostic accuracy studies. We reviewed each item in the statement for its applicability to clinical examination diagnostic accuracy research, viewing each discrete aspect of the history and physical examination as a diagnostic test. Setting Nonsystematic review of the STARD statement. Interventions Two former STARD Group participants and 1 editor of a journal series on clinical examination research reviewed each STARD item. Suggested interpretations and comments were shared to develop consensus. Measurements and Main Results The STARD Statement applies generally well to clinical examination diagnostic accuracy studies. Three items are the most important for clinical examination diagnostic accuracy studies, and investigators should pay particular attention to their requirements: describe carefully the patient recruitment process, describe participant sampling and address if patients were from a consecutive series, and describe whether the clinicians were masked to the reference standard tests and whether the interpretation of the reference standard test was masked to the clinical examination components or overall clinical impression. The consideration of these and the other STARD items in clinical examination diagnostic research studies would improve the quality of investigations and strengthen conclusions reached by practicing clinicians. Conclusions The STARD statement provides a very useful framework for diagnostic accuracy studies. The group correctly anticipated that there would be nuances applicable to studies of the clinical examination. We offer guidance that should enhance their usefulness to investigators embarking on original studies of a patient’s history and physical examination. PMID:18347878

Mobile diagnostics: next-generation technologies for in vitro diagnostics.

PubMed

Shin, Joonchul; Chakravarty, Sudesna; Choi, Wooseok; Lee, Kyungyeon; Han, Dongsik; Hwang, Hyundoo; Choi, Jaekyu; Jung, Hyo-Il

2018-03-26

The emergence of a wide range of applications of smartphones along with advances in 'liquid biopsy' has significantly propelled medical research particularly in the field of in vitro diagnostics (IVD). Herein, we have presented a detailed analysis of IVD, its associated critical concerns and probable solutions. It also demonstrates the transition in terms of analytes from minimally invasive (blood) to non-invasive (urine, saliva and sweat) and depicts how the different features of a smartphone can be integrated for specific diagnostic purposes. This review basically highlights recent advances in the applications of smartphone-based biosensors in IVD taking into account the following factors: accuracy and portability; quantitative and qualitative analysis; and centralization and decentralization tests. Furthermore, the critical concerns and future direction of diagnostics based on smartphones are also discussed.

READING DIAGNOSTIC APPROACHES.

ERIC Educational Resources Information Center

PURDY, ROBERT J.; AND OTHERS

A DIAGNOSTIC KIT DESIGNED TO HELP CLASSROOM TEACHERS DIAGNOSE READING DIFFICULTIES MORE ADEQUATELY AND MOTIVATE PUPILS MORE EFFECTIVELY IS PRESENTED. SUGGESTIONS ARE APPLICABLE TO LOWER PRIMARY CHILDREN. DIAGNOSTIC TECHNIQUES ARE OUTLINED FOR SUBJECTIVE AND OBJECTIVE OBSERVATION OF LANGUAGE ABILITY, VISUAL PERCEPTION SKILLS, AUDITORY…

Application of clinical techniques relevant for glaucoma assessment by optometrists: concordance with guidelines.

PubMed

Jamous, Khalid F; Kalloniatis, Michael; Hayen, Andrew; Mitchell, Paul; Stapleton, Fiona J; Zangerl, Barbara

2014-09-01

Guidelines for the screening, prognosis, diagnosis, management and prevention of glaucoma were released by the Australian National Health and Medical Research Council in 2010. Comparable guidance has been made available by respective bodies in the USA and UK at a similar time. Key to successful translation of guidelines into clinical practice includes clinicians having the necessary skills to perform required tests. Optometrists in Australia and New Zealand were invited to participate in an online survey exploring these aspects. The results provide insights for improving glaucoma diagnosis and management by optometric primary eye care practitioners. An online questionnaire was developed to investigate glaucoma assessment of optometrists as a function of demographic details, educational background and experience. Key points to ascertain compliance with current guidelines were the availability of equipment, procedural confidence in techniques, and preferences in visual field tests. Chi square statistics was employed to support similarity to national averages and highlight differences between the two countries. Multivariate linear regression analysis identified variables significantly associated with individual tests being available to optometrists and their confidence in applying them. Thirteen per cent of all Australian and 36% of the New Zealand optometrists responded to the survey in 2013, which reflected the demographics/geography of the practising populations. Techniques considered essential or preferred for glaucoma assessment were widely available in both countries with the exception of gonioscopy and pachymetry. After correcting for availability, regression models highlighted therapeutic endorsement and knowledge of glaucoma guidelines as the main variables to maintain high diagnostic confidence. Correlations to number of years in optometric practice mirrored a changed emphasis in teaching and technology over the past 10-15 years. Australian and New Zealand optometrists were well equipped to perform glaucoma assessments with the possible exception of gonioscopy. Advanced imaging modalities were not yet fully integrated into optometric practice, although optical coherence tomography has shown use by 23-32% of optometrists. A marked increase in use, availability and procedural confidence of gonioscopy and other techniques with therapeutically endorsed optometrists demonstrates the advantage and importance of additional training. © 2014 The Authors Ophthalmic & Physiological Optics © 2014 The College of Optometrists.

77 FR 72409 - Manufacturer of Controlled Substances; Notice of Application: Siemens Healthcare Diagnostics, Inc.

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-05

... DEPARTMENT OF JUSTICE Drug Enforcement Administration Manufacturer of Controlled Substances; Notice of Application: Siemens Healthcare Diagnostics, Inc. Pursuant to Sec. 1301.33(a) Title 21 of the Code of Federal Regulations (CFR), this is notice that on November 7, 2012, Siemens Healthcare...

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…

Research and Diagnostic Applications of Monoclonal Antibodies to Coccidioides immitis.

DTIC Science & Technology

1985-01-01

for Human and Animal Mycology , Georgia, May 1985. 17. COSATI CODES 18. SUBJECT TERMS (Co tinue on reverse if necessary and identify by block number...IX Congress of the International Society for Human and Animal Mycology , Atlanta GA, May 1985. ISHAM START ’IResearch and Diagnostic Applications of

A Novel System for Supporting Autism Diagnosis Using Home Videos: Iterative Development and Evaluation of System Design.

PubMed

Nazneen, Nazneen; Rozga, Agata; Smith, Christopher J; Oberleitner, Ron; Abowd, Gregory D; Arriaga, Rosa I

2015-06-17

Observing behavior in the natural environment is valuable to obtain an accurate and comprehensive assessment of a child's behavior, but in practice it is limited to in-clinic observation. Research shows significant time lag between when parents first become concerned and when the child is finally diagnosed with autism. This lag can delay early interventions that have been shown to improve developmental outcomes. To develop and evaluate the design of an asynchronous system that allows parents to easily collect clinically valid in-home videos of their child's behavior and supports diagnosticians in completing diagnostic assessment of autism. First, interviews were conducted with 11 clinicians and 6 families to solicit feedback from stakeholders about the system concept. Next, the system was iteratively designed, informed by experiences of families using it in a controlled home-like experimental setting and a participatory design process involving domain experts. Finally, in-field evaluation of the system design was conducted with 5 families of children (4 with previous autism diagnosis and 1 child typically developing) and 3 diagnosticians. For each family, 2 diagnosticians, blind to the child's previous diagnostic status, independently completed an autism diagnosis via our system. We compared the outcome of the assessment between the 2 diagnosticians, and between each diagnostician and the child's previous diagnostic status. The system that resulted through the iterative design process includes (1) NODA smartCapture, a mobile phone-based application for parents to record prescribed video evidence at home; and (2) NODA Connect, a Web portal for diagnosticians to direct in-home video collection, access developmental history, and conduct an assessment by linking evidence of behaviors tagged in the videos to the Diagnostic and Statistical Manual of Mental Disorders criteria. Applying clinical judgment, the diagnostician concludes a diagnostic outcome. During field evaluation, without prior training, parents easily (average rating of 4 on a 5-point scale) used the system to record video evidence. Across all in-home video evidence recorded during field evaluation, 96% (26/27) were judged as clinically useful, for performing an autism diagnosis. For 4 children (3 with autism and 1 typically developing), both diagnosticians independently arrived at the correct diagnostic status (autism versus typical). Overall, in 91% of assessments (10/11) via NODA Connect, diagnosticians confidently (average rating 4.5 on a 5-point scale) concluded a diagnostic outcome that matched with the child's previous diagnostic status. The in-field evaluation demonstrated that the system's design enabled parents to easily record clinically valid evidence of their child's behavior, and diagnosticians to complete a diagnostic assessment. These results shed light on the potential for appropriately designed telehealth technology to support clinical assessments using in-home video captured by families. This assessment model can be readily generalized to other conditions where direct observation of behavior plays a central role in the assessment process.

Diagnostic value of serum squamous cell carcinoma antigen for hepatocellular carcinoma: a systematic review and meta-analysis.

PubMed

Yu, Jing; Wang, Zhao-Juan; Chen, Long-Hua; Dong, Wen-Zhu

2017-02-01

The aim of this study was to ascertain the diagnostic value of serum squamous cell carcinoma antigen (SCCA) and SCCA-IgM for hepatocellular carcinoma (HCC). After a comprehensive search of PubMed and Web of Science databases, we identified eligible studies on the diagnostic value serum SCCAs for HCC. The quality of the eligible studies was assessed using the revised Quality Assessment for Studies of Diagnostic Accuracy (QUADAS-2) tool. The overall diagnostic value of SCCAs for HCC was pooled using a bivariate model. Twelve studies were included in this systematic review and meta-analysis. The pooled sensitivities for SCCA and SCCA-IgM were 0.61 (95% confidence interval [CI], 0.37-0.81) and 0.70 (95% CI, 0.55-0.82), respectively. The corresponding specificities were 0.80 (95% CI, 0.52-0.94) and 0.62 (95% CI, 0.51-0.72), respectively. The areas under summary receiver operating characteristic (sROC) curves for SCCA and SCCA-IgM were 0.76 (95% CI, 0.72-0.80) and 0.70 (95% CI, 0.66-0.74), respectively. Major design deficiencies of the included studies were two-gate design and partial verification bias. Therefore, we concluded that both serum SCCA and SCCA-IgM have a fair diagnostic value for HCC.

Psychiatric co-morbidity in multiple sclerosis: The risk of depression and anxiety before and after MS diagnosis.

PubMed

Hoang, Huong; Laursen, Bjarne; Stenager, Elsebeth N; Stenager, Egon

2016-03-01

Studies of depression and anxiety in multiple sclerosis (MS) patients have reported higher rates in MS patients than the general population. To estimate the risk of depression and anxiety and the use of tricyclic antidepressant and selective serotonin reuptake inhibitors (SSRI) prescriptions, in the pre-diagnostic and the post-diagnostic period of MS compared to the background population. A cohort of 5084 MS patients was included and matched with a control population of 24,771 persons linked to nationwide registers. Logistic regression analyses were performed estimating odds ratios (OR). In the pre-diagnostic period, the OR for having a diagnosis of depression and anxiety is 1.4 (95% confidence interval (CI) =1.05-1.88), and the OR of redemption prescriptions of TCAs is 1.90 (CI=1.54-2.34) and OR is 1.34 (CI= 1.20-1.51) for SSRI. In the post-diagnostic period the OR is 1.23 (CI= 0.92-1.64) for depression and anxiety diagnosis. The OR is 6.70 (CI=5.81-7.72) for TCA and OR is 2.46 (CI= 2.25-2.69) for SSRI. During both the pre- diagnostic and post-diagnostic period, MS patient have increased risk of depression and anxiety diagnoses and redemption of antidepressant and anxiolytic prescriptions, compared to the background population. © The Author(s), 2015.

Value of the Strain Ratio on Ultrasonic Elastography for Differentiation of Benign and Malignant Soft Tissue Tumors.

PubMed

Hahn, Seok; Lee, Young Han; Lee, Seung Hyun; Suh, Jin-Suck

2017-01-01

The purpose of this study was to evaluate whether the strain ratio provides additional value to conventional visual elasticity scores in the differentiation of benign and malignant soft tissue tumors by ultrasonic elastography. The Institutional Review Board approved the protocol of this retrospective review. Seventy-three patients who underwent elastography and had a soft tissue mass pathologically confirmed by ultrasound-guided core biopsy or surgical excision were enrolled from April 2012 through October 2014. On elastography, elasticity scores were determined with a 5-point visual scale, and the strain ratio to adjacent soft tissue at the same depth was calculated. Tumors were divided into benign and malignant groups according to the pathologic diagnoses. Elasticity scores and strain ratios were compared between benign and malignant groups, and diagnostic performance was evaluated by receiver operating characteristic curves. Of the 73 patients, 40 had benign tumors, and 33 had malignant tumors. Strain ratios (P = .003) and elasticity scores (P = .048) were significantly different between pathologic results. The areas under the receiver operating characteristic curves were 0.700 (95% confidence interval, 0.581-0.802) for the strain ratio and 0.623 (95% confidence interval, 0.515-0.746) for elastography. The strain ratios of malignant soft tissue tumors were lower than those of benign tumors and showed better diagnostic performance than did elasticity scores. The strain ratio can be used as a diagnostic indicator to predict the malignant potential of soft tissue tumors. © 2016 by the American Institute of Ultrasound in Medicine.

Breast cancer risk is increased in the years following false-positive breast cancer screening.

PubMed

Goossens, Mathijs C; De Brabander, Isabel; De Greve, Jacques; Vaes, Evelien; Van Ongeval, Chantal; Van Herck, Koen; Kellen, Eliane

2017-09-01

A small number of studies have investigated breast cancer (BC) risk among women with a history of false-positive recall (FPR) in BC screening, but none of them has used time-to-event analysis while at the same time quantifying the effect of false-negative diagnostic assessment (FNDA). FNDA occurs when screening detects BC, but this BC is missed on diagnostic assessment (DA). As a result of FNDA, screenings that detected cancer are incorrectly classified as FPR. Our study linked data recorded in the Flemish BC screening program (women aged 50-69 years) to data from the national cancer registry. We used Cox proportional hazards models on a retrospective cohort of 298 738 women to assess the association between FPR and subsequent BC, while adjusting for potential confounders. The mean follow-up was 6.9 years. Compared with women without recall, women with a history of FPR were at an increased risk of developing BC [hazard ratio=2.10 (95% confidence interval: 1.92-2.31)]. However, 22% of BC after FPR was due to FNDA. The hazard ratio dropped to 1.69 (95% confidence interval: 1.52-1.87) when FNDA was excluded. Women with FPR have a subsequently increased BC risk compared with women without recall. The risk is higher for women who have a FPR BI-RADS 4 or 5 compared with FPR BI-RADS 3. There is room for improvement of diagnostic assessment: 41% of the excess risk is explained by FNDA after baseline screening.

Factors influencing the probability of a diagnosis of autism spectrum disorder in girls versus boys.

PubMed

Duvekot, Jorieke; van der Ende, Jan; Verhulst, Frank C; Slappendel, Geerte; van Daalen, Emma; Maras, Athanasios; Greaves-Lord, Kirstin

2017-08-01

In order to shed more light on why referred girls are less likely to be diagnosed with autism spectrum disorder than boys, this study examined whether behavioral characteristics influence the probability of an autism spectrum disorder diagnosis differently in girls versus boys derived from a multicenter sample of consecutively referred children aged 2.5-10 years. Based on information from the short version of the Developmental, Dimensional and Diagnostic Interview and the Autism Diagnostic Observation Schedule, 130 children (106 boys and 24 girls) received a diagnosis of autism spectrum disorder according to Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.) criteria and 101 children (61 boys and 40 girls) did not. Higher overall levels of parent-reported repetitive and restricted behavior symptoms were less predictive of an autism spectrum disorder diagnosis in girls than in boys (odds ratio interaction = 0.41, 95% confidence interval = 0.18-0.92, p = 0.03). In contrast, higher overall levels of parent-reported emotional and behavioral problems increased the probability of an autism spectrum disorder diagnosis more in girls than in boys (odds ratio interaction = 2.44, 95% confidence interval = 1.13-5.29, p = 0.02). No differences were found between girls and boys in the prediction of an autism spectrum disorder diagnosis by overall autistic impairment, sensory symptoms, and cognitive functioning. These findings provide insight into possible explanations for the assumed underidentification of autism spectrum disorder in girls in the clinic.

Clinician, patient and general public beliefs about diagnostic imaging for low back pain: protocol for a qualitative evidence synthesis.

PubMed

Traeger, Adrian C; Reed, Benjamin J; O'Connor, Denise A; Hoffmann, Tammy C; Machado, Gustavo C; Bonner, Carissa; Maher, Chris G; Buchbinder, Rachelle

2018-02-10

Little is known about how to reduce unnecessary imaging for low back pain. Understanding clinician, patient and general public beliefs about imaging is critical to developing strategies to reduce overuse. To synthesise qualitative research that has explored clinician, patient or general public beliefs about diagnostic imaging for low back pain. We will perform a qualitative evidence synthesis of relevant qualitative research exploring clinician, patient and general public beliefs about diagnostic imaging for low back pain. Exclusions will be studies not using qualitative methods and studies not published in English. Studies will be identified using sensitive search strategies in MEDLINE, EMBASE, CINAHL, AMED and PsycINFO. Two reviewers will independently apply inclusion and exclusion criteria, extract data, and use the Critical Appraisal Skills Programme quality assessment tool to assess the quality of included studies. To synthesise the data we will use a narrative synthesis approach that involves developing a theoretical model, conducting a preliminary synthesis, exploring relations in the data, and providing a structured summary. We will code the data using NVivo. At least two reviewers will independently apply the thematic framework to extracted data. Confidence in synthesis findings will be evaluated using the GRADE Confidence in the Evidence from Reviews of Qualitative Research tool. Ethical approval is not required to conduct this review. We will publish the results in a peer-reviewed journal. CRD42017076047. © 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.

Body weight lower limits of fetal postmortem MRI at 1.5 T.

PubMed

Jawad, N; Sebire, N J; Wade, A; Taylor, A M; Chitty, L S; Arthurs, O J

2016-07-01

To evaluate the diagnostic yield of postmortem magnetic resonance imaging (PM-MRI) compared with conventional autopsy in fetuses of early gestational age and low body weight. Fetuses of < 31 weeks' gestation that underwent 1.5-T PM-MRI and conventional autopsy were included. The findings of PM-MRI and conventional autopsy were reported blinded to each other. The reports of conventional autopsy and PM-MRI for each organ system (cardiovascular, neurological, abdominal, non-cardiac thoracic and musculoskeletal) were classified as either diagnostic or non-diagnostic. The likelihood of a non-diagnostic examination by PM-MRI was calculated according to fetal gestational age and body weight. Full datasets were examined of 204 fetuses, with mean gestational age of 20.95 ± 3.82 weeks (range, 12.0-30.7 weeks) and body-weight range of 15.9-1872 g. Body weight was the most significant predictor of diagnostic yield of PM-MRI. There was 95% confidence that 90% of fetuses will show diagnostic images by PM-MRI for all five organ systems when fetal body weight is ≥ 535 g, but < 50% of fetuses will have all five systems diagnostic on PM-MRI when body weight is < 122 g. PM-MRI is highly likely to provide adequate diagnostic images for fetuses with a body weight > 500 g. Below this weight, the diagnostic yield of standard 1.5-T PM-MRI decreases significantly. These data should help inform parents and clinicians on the suitability of performing PM-MRI in fetuses with low body weight. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Word Memory Test Predicts Recovery in Claimants With Work-Related Head Injury.

PubMed

Colangelo, Annette; Abada, Abigail; Haws, Calvin; Park, Joanne; Niemeläinen, Riikka; Gross, Douglas P

2016-05-01

To investigate the predictive validity of the Word Memory Test (WMT), a verbal memory neuropsychological test developed as a performance validity measure to assess memory, effort, and performance consistency. Cohort study with 1-year follow-up. Workers' compensation rehabilitation facility. Participants included workers' compensation claimants with work-related head injury (N=188; mean age, 44y; 161 men [85.6%]). Not applicable. Outcome measures for determining predictive validity included days to suspension of wage replacement benefits during the 1-year follow-up and work status at discharge in claimants undergoing rehabilitation. Analysis included multivariable Cox and logistic regression. Better WMT performance was significantly but weakly correlated with younger age (r=-.30), documented brain abnormality (r=.28), and loss of consciousness at the time of injury (r=.25). Claimants with documented brain abnormalities on diagnostic imaging scans performed better (∼9%) on the WMT than those without brain abnormalities. The WMT predicted days receiving benefits (adjusted hazard ratio, 1.13; 95% confidence interval, 1.04-1.24) and work status outcome at program discharge (adjusted odds ratio, 1.62; 95% confidence interval, 1.13-2.34). Our results provide evidence for the predictive validity of the WMT in workers' compensation claimants. Younger claimants and those with more severe brain injuries performed better on the WMT. It may be that financial incentives or other factors related to the compensation claim affected the performance. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Nanotechnology in Urology

PubMed Central

Jayasimha, Sudhindra

2017-01-01

Introduction: Nanotechnology has revolutionized our approach to medical diagnostics as well as therapeutics and has spanned an entirely new branch of research. This review addresses the potential applications of Nanotechnology in Urology. This article is based on the Dr. Sitharaman Best Essay award of the Urological Society of India for 2016. Methods: A PubMed search was performed for all relevant articles using the terms, “nanotechnology, nanoparticles, nanoshells, nanoscaffolds, and nanofibers.” Results: The developments in diagnostics include novel techniques of imaging of genitourinary malignancies, prostate-specific antigen measurement, early detection of mutations that are diagnostic for polycystic kidney disease. The potential applications of nanotechnology are in the targeted therapy of genitourinary malignancies, erectile dysfunction, overactive bladder, bladder reconstruction, construction of artificial kidneys and biodegradable stents as well as in robotic surgery. Conclusions: Nanotechnology is a rapidly emerging branch of research in urology with diverse and clinically significant applications in diagnostics as well as therapeutics. PMID:28197024

Microgravity Combustion Diagnostics Workshop

NASA Technical Reports Server (NTRS)

Santoro, Gilbert J. (Editor); Greenberg, Paul S. (Editor); Piltch, Nancy D. (Editor)

1988-01-01

Through the Microgravity Science and Applications Division (MSAD) of the Office of Space Science and Applications (OSSA) at NASA Headquarters, a program entitled, Advanced Technology Development (ATD) was promulgated with the objective of providing advanced technologies that will enable the development of future microgravity science and applications experimental flight hardware. Among the ATD projects one, Microgravity Combustion Diagnostics (MCD), has the objective of developing advanced diagnostic techniques and technologies to provide nonperturbing measurements of combustion characteristics and parameters that will enhance the scientific integrity and quality of microgravity combustion experiments. As part of the approach to this project, a workshop was held on July 28 and 29, 1987, at the NASA Lewis Research Center. A small group of laser combustion diagnosticians met with a group of microgravity combustion experimenters to discuss the science requirements, the state-of-the-art of laser diagnostic technology, and plan the direction for near-, intermediate-, and long-term programs. This publication describes the proceedings of that workshop.

Integrated Data Analysis for Fusion: A Bayesian Tutorial for Fusion Diagnosticians

NASA Astrophysics Data System (ADS)

Dinklage, Andreas; Dreier, Heiko; Fischer, Rainer; Gori, Silvio; Preuss, Roland; Toussaint, Udo von

2008-03-01

Integrated Data Analysis (IDA) offers a unified way of combining information relevant to fusion experiments. Thereby, IDA meets with typical issues arising in fusion data analysis. In IDA, all information is consistently formulated as probability density functions quantifying uncertainties in the analysis within the Bayesian probability theory. For a single diagnostic, IDA allows the identification of faulty measurements and improvements in the setup. For a set of diagnostics, IDA gives joint error distributions allowing the comparison and integration of different diagnostics results. Validation of physics models can be performed by model comparison techniques. Typical data analysis applications benefit from IDA capabilities of nonlinear error propagation, the inclusion of systematic effects and the comparison of different physics models. Applications range from outlier detection, background discrimination, model assessment and design of diagnostics. In order to cope with next step fusion device requirements, appropriate techniques are explored for fast analysis applications.

Exploring virtual reality technology and the Oculus Rift for the examination of digital pathology slides.

PubMed

Farahani, Navid; Post, Robert; Duboy, Jon; Ahmed, Ishtiaque; Kolowitz, Brian J; Krinchai, Teppituk; Monaco, Sara E; Fine, Jeffrey L; Hartman, Douglas J; Pantanowitz, Liron

2016-01-01

Digital slides obtained from whole slide imaging (WSI) platforms are typically viewed in two dimensions using desktop personal computer monitors or more recently on mobile devices. To the best of our knowledge, we are not aware of any studies viewing digital pathology slides in a virtual reality (VR) environment. VR technology enables users to be artificially immersed in and interact with a computer-simulated world. Oculus Rift is among the world's first consumer-targeted VR headsets, intended primarily for enhanced gaming. Our aim was to explore the use of the Oculus Rift for examining digital pathology slides in a VR environment. An Oculus Rift Development Kit 2 (DK2) was connected to a 64-bit computer running Virtual Desktop software. Glass slides from twenty randomly selected lymph node cases (ten with benign and ten malignant diagnoses) were digitized using a WSI scanner. Three pathologists reviewed these digital slides on a 27-inch 5K display and with the Oculus Rift after a 2-week washout period. Recorded endpoints included concordance of final diagnoses and time required to examine slides. The pathologists also rated their ease of navigation, image quality, and diagnostic confidence for both modalities. There was 90% diagnostic concordance when reviewing WSI using a 5K display and Oculus Rift. The time required to examine digital pathology slides on the 5K display averaged 39 s (range 10-120 s), compared to 62 s with the Oculus Rift (range 15-270 s). All pathologists confirmed that digital pathology slides were easily viewable in a VR environment. The ratings for image quality and diagnostic confidence were higher when using the 5K display. Using the Oculus Rift DK2 to view and navigate pathology whole slide images in a virtual environment is feasible for diagnostic purposes. However, image resolution using the Oculus Rift device was limited. Interactive VR technologies such as the Oculus Rift are novel tools that may be of use in digital pathology.

Procalcitonin as a diagnostic test for sepsis in critically ill adults and after surgery or trauma: a systematic review and meta-analysis.

PubMed

Uzzan, Bernard; Cohen, Régis; Nicolas, Patrick; Cucherat, Michel; Perret, Gérard-Yves

2006-07-01

To quantify the accuracy of serum procalcitonin as a diagnostic test for sepsis, severe sepsis, or septic shock in adults in intensive care units or after surgery or trauma, alone and compared with C-reactive protein. To draw and compare the summary receiver operating characteristics curves for procalcitonin and C-reactive protein from the literature. MEDLINE (keywords: procalcitonin, intensive care, sepsis, postoperative sepsis, trauma); screening of the literature. Meta-analysis of all 49 published studies in medical, surgical, or polyvalent intensive care units or postoperative wards. Children, medical patients, and immunocompromised patients were excluded. Thirty-three studies fulfilled inclusion criteria (3,943 patients, 1,828 males, 922 females; mean age: 56.1 yrs; 1,825 patients with sepsis, severe sepsis, or septic shock; 1,545 with only systemic inflammatory response syndrome); eight studies could not be analyzed statistically. Global mortality rate was 29.3%. Global odds ratios for diagnosis of infection complicated by systemic inflammation were 15.7 for the 25 studies (2,966 patients) using procalcitonin (95% confidence interval, 9.1-27.1) and 5.4 for the 15 studies (1,322 patients) using C-reactive protein (95% confidence interval, 3.2-9.2). The summary receiver operating characteristics curve for procalcitonin was better than for C-reactive protein. In the 15 studies using both markers, the Q* value (intersection of summary receiver operating characteristics curve with the diagonal line where sensitivity equals specificity) was significantly higher for procalcitonin than for C-reactive protein (0.78 vs. 0.71, p = .02), the former test showing better accuracy. Procalcitonin represents a good biological diagnostic marker for sepsis, severe sepsis, or septic shock, difficult diagnoses in critically ill patients. Procalcitonin is superior to C-reactive protein. Procalcitonin should be included in diagnostic guidelines for sepsis and in clinical practice in intensive care units.

Beyond Correctness: Development and Validation of Concept-Based Categorical Scoring Rubrics for Diagnostic Purposes

ERIC Educational Resources Information Center

Arieli-Attali, Meirav; Liu, Ying

2016-01-01

Diagnostic assessment approaches intend to provide fine-grained reports of what students know and can do, focusing on their areas of strengths and weaknesses. However, current application of such diagnostic approaches is limited by the scoring method for item responses; important diagnostic information, such as type of errors and strategy use is…

Clinical Issues in the Use of the "DSM-III-R" with African American Children: A Diagnostic Paradigm.

ERIC Educational Resources Information Center

Johnson, Ronn

1993-01-01

Reviews concerns related to diagnoses in delivery of mental health services, specifically, application of the principles of the Diagnostic and Statistical Manual of Mental Health Disorders (DSM-III-R) to African-American children. An alternative diagnostic model is proposed, and recommendations are made for enhancing the diagnostic process. (SLD)

Improvement of Railroad Roller Bearing Test Procedures & Development of Roller Bearing Diagnostic Techniques. Volume 2.

DOT National Transportation Integrated Search

1982-04-01

A comprehensive review of existing basic diagnostic techniques applicable to the railcar roller bearing defect and failure problem was made. Of the potentially feasible diagnostic techniques identified, high frequency vibration was selected for exper...

Confidence intervals for the population mean tailored to small sample sizes, with applications to survey sampling.

PubMed

Rosenblum, Michael A; Laan, Mark J van der

2009-01-07

The validity of standard confidence intervals constructed in survey sampling is based on the central limit theorem. For small sample sizes, the central limit theorem may give a poor approximation, resulting in confidence intervals that are misleading. We discuss this issue and propose methods for constructing confidence intervals for the population mean tailored to small sample sizes. We present a simple approach for constructing confidence intervals for the population mean based on tail bounds for the sample mean that are correct for all sample sizes. Bernstein's inequality provides one such tail bound. The resulting confidence intervals have guaranteed coverage probability under much weaker assumptions than are required for standard methods. A drawback of this approach, as we show, is that these confidence intervals are often quite wide. In response to this, we present a method for constructing much narrower confidence intervals, which are better suited for practical applications, and that are still more robust than confidence intervals based on standard methods, when dealing with small sample sizes. We show how to extend our approaches to much more general estimation problems than estimating the sample mean. We describe how these methods can be used to obtain more reliable confidence intervals in survey sampling. As a concrete example, we construct confidence intervals using our methods for the number of violent deaths between March 2003 and July 2006 in Iraq, based on data from the study "Mortality after the 2003 invasion of Iraq: A cross sectional cluster sample survey," by Burnham et al. (2006).

On the Prevalence of Alternative Conceptions on Acid-Base Chemistry among Secondary Students: Insights from Cognitive and Confidence Measures

ERIC Educational Resources Information Center

Hoe, Kai Yee; Subramaniam, R.

2016-01-01

This study presents an analysis of alternative conceptions (ACs) on acid--base chemistry harbored by grade 9 students in Singapore. The ACs were obtained by the development and validation of a 4-tier diagnostic instrument. It is among the very few studies in the science education literature that have focused on examining results based also on…

Temporal Comparisons of Internet Topology

DTIC Science & Technology

2014-06-01

Number CAIDA Cooperative Association of Internet Data Analysis CDN Content Delivery Network CI Confidence Interval DoS denial of service GMT Greenwich...the CAIDA data. Our methods include analysis of graph theoretical measures as well as complex network and statistical measures that will quantify the...tool that probes the Internet for topology analysis and performance [26]. Scamper uses network diagnostic tools, such as traceroute and ping, to probe

Image Noise, CNR, and Detectability of Low-Contrast, Low-Attenuation Liver Lesions in a Phantom: Effects of Radiation Exposure, Phantom Size, Integrated Circuit Detector, and Iterative Reconstruction.

PubMed

Goenka, Ajit H; Herts, Brian R; Dong, Frank; Obuchowski, Nancy A; Primak, Andrew N; Karim, Wadih; Baker, Mark E

2016-08-01

Purpose To assess image noise, contrast-to-noise ratio (CNR) and detectability of low-contrast, low-attenuation liver lesions in a semianthropomorphic phantom by using either a discrete circuit (DC) detector and filtered back projection (FBP) or an integrated circuit (IC) detector and iterative reconstruction (IR) with changes in radiation exposure and phantom size. Materials and Methods An anthropomorphic phantom without or with a 5-cm-thick fat-mimicking ring (widths, 30 and 40 cm) containing liver inserts with four spherical lesions was scanned with five exposure settings on each of two computed tomography scanners, one equipped with a DC detector and the other with an IC detector. Images from the DC and IC detector scanners were reconstructed with FBP and IR, respectively. Image noise and lesion CNR were measured. Four radiologists evaluated lesion presence on a five-point diagnostic confidence scale. Data analyses included receiver operating characteristic (ROC) curve analysis and noninferiority analysis. Results The combination of IC and IR significantly reduced image noise (P < .001) (with the greatest reduction in the 40-cm phantom and at lower exposures) and improved lesion CNR (P < .001). There was no significant difference in area under the ROC curve between detector-reconstruction combinations at fixed exposure for either phantom. Reader accuracy with IC-IR was noninferior at 50% (100 mAs [effective]) and 25% (300 mAs [effective]) exposure reduction for the 30- and 40-cm phantoms, respectively (adjusted P < .001 and .04 respectively). IC-IR improved readers' confidence in the presence of a lesion (P = .029) independent of phantom size or exposure level. Conclusion IC-IR improved objective image quality and lesion detection confidence but did not result in superior diagnostic accuracy when compared with DC-FBP. Moderate exposure reductions maintained comparable diagnostic accuracy for both detector-reconstruction combinations. Lesion detection in the 40-cm phantom was inferior at smaller exposure reduction than in the 30-cm phantom. (©) RSNA, 2016 Online supplemental material is available for this article.

Assessment of Bowel Wall Enhancement for the Diagnosis of Intestinal Ischemia in Patients with Small Bowel Obstruction: Value of Adding Unenhanced CT to Contrast-enhanced CT.

PubMed

Chuong, Anh Minh; Corno, Lucie; Beaussier, Hélène; Boulay-Coletta, Isabelle; Millet, Ingrid; Hodel, Jérôme; Taourel, Patrice; Chatellier, Gilles; Zins, Marc

2016-07-01

Purpose To determine whether adding unenhanced computed tomography (CT) to contrast material-enhanced CT improves the diagnostic performance of decreased bowel wall enhancement as a sign of ischemia complicating mechanical small bowel obstruction (SBO). Materials and Methods This retrospective study was approved by the institutional review board, which waived the requirement for informed consent. Two gastrointestinal radiologists independently performed retrospective assessments of 164 unenhanced and contrast-enhanced CT studies from 158 consecutive patients (mean age, 71.2 years) with mechanical SBO. The reference standard was the intraoperative and/or histologic diagnosis (in 80 cases) or results from clinical follow-up in patients who did not undergo surgery (84 cases). Decreased bowel wall enhancement was evaluated with contrast-enhanced images then and both unenhanced and contrast-enhanced images 1 month later. Diagnostic performance of decreased bowel wall enhancement and confidence in the diagnosis were compared between the two readings by using McNemar and Wilcoxon signed rank tests. Interobserver agreement was assessed by using κ statistics and compared with bootstrapping. Results Ischemia was diagnosed in 41 of 164 (25%) episodes of SBO. For both observers, adding unenhanced images improved decreased bowel wall enhancement sensitivity (observer 1: 46.3% [19 of 41] vs 65.8% [27 of 41], P = .02; observer 2: 56.1% [23 of 41] vs 63.4% [26 of 41], P = .45), Youden index (from 0.41 to 0.58 for observer 1 and from 0.42 to 0.61 for observer 2), and confidence score (P < .001 for both). Specificity significantly increased for observer 2 (84.5% [104 of 123] vs 94.3% [116 of 123], P = .002), and interobserver agreement significantly increased, from moderate (κ = 0.48) to excellent (κ = 0.89; P < .0001). Conclusion Adding unenhanced CT to contrast-enhanced CT improved the sensitivity, diagnostic confidence, and interobserver agreement of the diagnosis of ischemia, a complication of mechanical SBO, on the basis of decreased bowel wall enhancement. (©) RSNA, 2016.

Clinical evaluation of a mobile digital specimen radiography system for intraoperative specimen verification.

PubMed

Wang, Yingbing; Ebuoma, Lilian; Saksena, Mansi; Liu, Bob; Specht, Michelle; Rafferty, Elizabeth

2014-08-01

Use of mobile digital specimen radiography systems expedites intraoperative verification of excised breast specimens. The purpose of this study was to evaluate the performance of a such a system for verifying targets. A retrospective review included 100 consecutive pairs of breast specimen radiographs. Specimens were imaged in the operating room with a mobile digital specimen radiography system and then with a conventional digital mammography system in the radiology department. Two expert reviewers independently scored each image for image quality on a 3-point scale and confidence in target visualization on a 5-point scale. A target was considered confidently verified only if both reviewers declared the target to be confidently detected. The 100 specimens contained a total of 174 targets, including 85 clips (49%), 53 calcifications (30%), 35 masses (20%), and one architectural distortion (1%). Although a significantly higher percentage of mobile digital specimen radiographs were considered poor quality by at least one reviewer (25%) compared with conventional digital mammograms (1%), 169 targets (97%), were confidently verified with mobile specimen radiography; 172 targets (98%) were verified with conventional digital mammography. Three faint masses were not confidently verified with mobile specimen radiography, and conventional digital mammography was needed for confirmation. One faint mass and one architectural distortion were not confidently verified with either method. Mobile digital specimen radiography allows high diagnostic confidence for verification of target excision in breast specimens across target types, despite lower image quality. Substituting this modality for conventional digital mammography can eliminate delays associated with specimen transport, potentially decreasing surgical duration and increasing operating room throughput.

Semiconductor Quantum Dots for Bioimaging and Biodiagnostic Applications

NASA Astrophysics Data System (ADS)

Kairdolf, Brad A.; Smith, Andrew M.; Stokes, Todd H.; Wang, May D.; Young, Andrew N.; Nie, Shuming

2013-06-01

Semiconductor quantum dots (QDs) are light-emitting particles on the nanometer scale that have emerged as a new class of fluorescent labels for chemical analysis, molecular imaging, and biomedical diagnostics. Compared with traditional fluorescent probes, QDs have unique optical and electronic properties such as size-tunable light emission, narrow and symmetric emission spectra, and broad absorption spectra that enable the simultaneous excitation of multiple fluorescence colors. QDs are also considerably brighter and more resistant to photobleaching than are organic dyes and fluorescent proteins. These properties are well suited for dynamic imaging at the single-molecule level and for multiplexed biomedical diagnostics at ultrahigh sensitivity. Here, we discuss the fundamental properties of QDs; the development of next-generation QDs; and their applications in bioanalytical chemistry, dynamic cellular imaging, and medical diagnostics. For in vivo and clinical imaging, the potential toxicity of QDs remains a major concern. However, the toxic nature of cadmium-containing QDs is no longer a factor for in vitro diagnostics, so the use of multicolor QDs for molecular diagnostics and pathology is probably the most important and clinically relevant application for semiconductor QDs in the immediate future.

Semiconductor quantum dots for bioimaging and biodiagnostic applications.

PubMed

Kairdolf, Brad A; Smith, Andrew M; Stokes, Todd H; Wang, May D; Young, Andrew N; Nie, Shuming

2013-01-01

Semiconductor quantum dots (QDs) are light-emitting particles on the nanometer scale that have emerged as a new class of fluorescent labels for chemical analysis, molecular imaging, and biomedical diagnostics. Compared with traditional fluorescent probes, QDs have unique optical and electronic properties such as size-tunable light emission, narrow and symmetric emission spectra, and broad absorption spectra that enable the simultaneous excitation of multiple fluorescence colors. QDs are also considerably brighter and more resistant to photobleaching than are organic dyes and fluorescent proteins. These properties are well suited for dynamic imaging at the single-molecule level and for multiplexed biomedical diagnostics at ultrahigh sensitivity. Here, we discuss the fundamental properties of QDs; the development of next-generation QDs; and their applications in bioanalytical chemistry, dynamic cellular imaging, and medical diagnostics. For in vivo and clinical imaging, the potential toxicity of QDs remains a major concern. However, the toxic nature of cadmium-containing QDs is no longer a factor for in vitro diagnostics, so the use of multicolor QDs for molecular diagnostics and pathology is probably the most important and clinically relevant application for semiconductor QDs in the immediate future.

Semiconductor Quantum Dots for Bioimaging and Biodiagnostic Applications

PubMed Central

Kairdolf, Brad A.; Smith, Andrew M.; Stokes, Todd H.; Wang, May D.; Young, Andrew N.; Nie, Shuming

2013-01-01

Semiconductor quantum dots (QDs) are light-emitting particles on the nanometer scale that have emerged as a new class of fluorescent labels for chemical analysis, molecular imaging, and biomedical diagnostics. Compared with traditional fluorescent probes, QDs have unique optical and electronic properties such as size-tunable light emission, narrow and symmetric emission spectra, and broad absorption spectra that enable the simultaneous excitation of multiple fluorescence colors. QDs are also considerably brighter and more resistant to photobleaching than are organic dyes and fluorescent proteins. These properties are well suited for dynamic imaging at the single-molecule level and for multiplexed biomedical diagnostics at ultrahigh sensitivity. Here, we discuss the fundamental properties of QDs; the development of next-generation QDs; and their applications in bioanalytical chemistry, dynamic cellular imaging, and medical diagnostics. For in vivo and clinical imaging, the potential toxicity of QDs remains a major concern. However, the toxic nature of cadmium-containing QDs is no longer a factor for in vitro diagnostics, so the use of multicolor QDs for molecular diagnostics and pathology is probably the most important and clinically relevant application for semiconductor QDs in the immediate future. PMID:23527547

Factors affecting initial disability allowance rates for the Disability Insurance and Supplemental Security Income programs: the role of the demographic and diagnostic composition of applicants and local labor market conditions.

PubMed

Rupp, Kalman

2012-01-01

Various factors outside the control of decision makers may affect the rate at which disability applications are allowed or denied during the initial step of eligibility determination in the Social Security Disability Insurance (DI) and Supplemental Security Income (SSI) programs. In this article, using individual-level data on applications, I estimate the role of three important factors--the demographic characteristics of applicants, the diagnostic mix of applicants, and the local unemployment rate--in affecting the probability of an initial allowance and state allowance rates. I use a random sample of initial determinations from 1993 through 2008 and a fixed-effects multiple regression framework. The empirical results show that the demographic and diagnostic characteristics of applicants and the local unemployment rate substantially affect the initial allowance rate. An increase in the local unemployment rate tends to be associated with a decrease in the initial allowance rate. This negative relationship holds for adult DI and SSI applicants and for SSI childhood applicants.

Towards advanced OCT clinical applications

NASA Astrophysics Data System (ADS)

Kirillin, Mikhail; Panteleeva, Olga; Agrba, Pavel; Pasukhin, Mikhail; Sergeeva, Ekaterina; Plankina, Elena; Dudenkova, Varvara; Gubarkova, Ekaterina; Kiseleva, Elena; Gladkova, Natalia; Shakhova, Natalia; Vitkin, Alex

2015-07-01

In this paper we report on our recent achievement in application of conventional and cross-polarization OCT (CP OCT) modalities for in vivo clinical diagnostics in different medical areas including gynecology, dermatology, and stomatology. In gynecology, CP OCT was employed for diagnosing fallopian tubes and cervix; in dermatology OCT for monitoring of treatment of psoriasis, scleroderma and atopic dermatitis; and in stomatology for diagnosis of oral diseases. For all considered application, we propose and develop different image processing methods which enhance the diagnostic value of the technique. In particular, we use histogram analysis, Fourier analysis and neural networks, thus calculating different tissue characteristics as revealed by OCT's polarization evolution. These approaches enable improved OCT image quantification and increase its resultant diagnostic accuracy.

Diagnostic value of secreted frizzled-related protein 2 gene promoter hypermethylation in stool for colorectal cancer: A meta-analysis.

PubMed

Zhou, Zhiran; Zhang, Huitian; Lei, Yunxia

2016-10-01

To evaluate the diagnostic value of secreted frizzled-related protein 2 (SFRP2) gene promoter hypermethylation in stool for colorectal cancer (CRC). Open published diagnostic study of SFRP2 gene promoter hypermethylation in stool for CRC detection was electronic searched in the databases of PubMed, EMBASE, Cochrane Library, Web of Science, and China National Knowledge Infrastructure. The data of true positive, false positive false negative, and true negative identified by stool SFRP2 gene hypermethylation was extracted and pooled for diagnostic sensitivity, specificity, and summary receiver operating characteristic (SROC) curve. According to the inclusion and exclusion criteria, we finally included nine publications with 792 cases in the meta-analysis. Thus, the diagnostic sensitivity was aggregated through random effect model. The pooled sensitivity was 0.82 with the corresponding 95% confidence interval (95% CI) of 0.79-0.85; the pooled specificity and its corresponding 95% CI were 0.47 and 0.40-0.53 by the random effect model; we pooled the SROC curve by sensitivity versus specificity according to data published in the nine studies. The area under the SROC curve was 0.70 (95% CI: 0.65-0.73). SFRP2 gene promoter hypermethylation in stool can was a potential biomarker for CRC diagnosis with relative high sensitivity.

Host-guest supramolecular nanosystems for cancer diagnostics and therapeutics.

PubMed

Wang, Lei; Li, Li-li; Fan, Yun-shan; Wang, Hao

2013-07-26

Extensive efforts have been devoted to the construction of functional supramolecular nanosystems for applications in catalysis, energy conversion, sensing and biomedicine. The applications of supramolecular nanosystems such as liposomes, micelles, inorganic nanoparticles, carbon materials for cancer diagnostics and therapeutics have been reviewed by other groups. Here, we will focus on the recent momentous advances in the implementation of typical supramolecular hosts (i.e., cyclodextrins, calixarenes, cucurbiturils and metallo-hosts) and their nanosystems in cancer diagnostics and therapeutics. We discuss the evolutive process of supramolecular nanosystems from the structural control and characterization to their diagnostic and therapeutic function exploitation and even the future potentials for clinical translation. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Influence of Causal Explanations and Diagnostic Labeling on Psychology Students' Beliefs About Treatments, Prognosis, Dangerousness and Unpredictability in Schizophrenia.

PubMed

Magliano, Lorenza; Read, John; Rinaldi, Angela; Costanzo, Regina; De Leo, Renata; Schioppa, Giustina; Petrillo, Miriam

2016-04-01

This study explored views of 566 Italian psychology students about schizophrenia. The most frequently cited causes were psychological traumas (68 %) and heredity (54 %). Thirty-three percent of students firmly believed that people with the condition could recover. Reporting heredity among the causes, and identifying schizophrenia were both associated with prognostic pessimism, greater confidence in pharmacological treatments and lower confidence in psychological treatments. Schizophrenia labeling was also associated with higher perception of unpredictability and dangerousness. Compared to first year students, fourth/fifth year students more frequently reported heredity among the causes, and were more pessimistic about schizophrenia recovery. Stigma topics should be included in future psychologists' education.

Real-time sensor validation and fusion for distributed autonomous sensors

NASA Astrophysics Data System (ADS)

Yuan, Xiaojing; Li, Xiangshang; Buckles, Bill P.

2004-04-01

Multi-sensor data fusion has found widespread applications in industrial and research sectors. The purpose of real time multi-sensor data fusion is to dynamically estimate an improved system model from a set of different data sources, i.e., sensors. This paper presented a systematic and unified real time sensor validation and fusion framework (RTSVFF) based on distributed autonomous sensors. The RTSVFF is an open architecture which consists of four layers - the transaction layer, the process fusion layer, the control layer, and the planning layer. This paradigm facilitates distribution of intelligence to the sensor level and sharing of information among sensors, controllers, and other devices in the system. The openness of the architecture also provides a platform to test different sensor validation and fusion algorithms and thus facilitates the selection of near optimal algorithms for specific sensor fusion application. In the version of the model presented in this paper, confidence weighted averaging is employed to address the dynamic system state issue noted above. The state is computed using an adaptive estimator and dynamic validation curve for numeric data fusion and a robust diagnostic map for decision level qualitative fusion. The framework is then applied to automatic monitoring of a gas-turbine engine, including a performance comparison of the proposed real-time sensor fusion algorithms and a traditional numerical weighted average.

System theory in medical diagnostic devices: an overview.

PubMed

Baura, Gail D

2006-01-01

Medical diagnostics refers to testing conducted either in vitro or in vivo to provide critical health care information for risk assessment, early diagnosis, treatment, or disease management. Typical in vivo diagnostic tests include the computed tomography scan, magnetic resonance imaging, and blood pressure screening. Typical in vitro diagnostic tests include cholesterol, Papanicolaou smear, and conventional glucose monitoring tests. Historically, devices associated with both types of diagnostics have used heuristic curve fitting during signal analysis. However, since the early 1990s, a few enterprising engineers and physicians have used system theory to improve their core processing for feature detection and system identification. Current applications include automated Pap smear screening for detection of cervical cancer and diagnosis of Alzheimer's disease. Future applications, such as disease prediction before symptom onset and drug treatment customization, have been catalyzed by the Human Genome Project.

Active and Passive Diagnostic Signatures of Special Nuclear Materials

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

Myers, William L.; Karpius, Peter Joseph; Myers, Steven Charles

2017-05-26

An overview will be given discussing signatures associated with special nuclear materials acquired using both active and passive diagnostic techniques. Examples of how technology advancements have helped improve diagnostic capabilities to meet the challenges of today’s applications will be discussed.

Reliability among clinicians diagnosing low back-related leg pain.

PubMed

Stynes, Siobhán; Konstantinou, Kika; Dunn, Kate M; Lewis, Martyn; Hay, Elaine M

2016-09-01

To investigate agreement and reliability among clinicians when diagnosing low back-related leg pain (LBLP) in primary care consulters. Thirty-six patients were assessed by one of six physiotherapists and diagnosed as having either leg pain due to nerve root involvement (sciatica) or referred leg pain. Assessments were video recorded. In part one, the physiotherapists each viewed videos of six patients they had not assessed. In part two, videos were viewed by another six health professionals. All clinicians made an independent differential diagnosis and rated their confidence with diagnosis (range 50-100 %). In part one agreement was 72 % with fair inter-rater reliability (K = 0.35, 95 % CI 0.07, 0.63). Results for part two were almost identical (K = 0.34, 95 % CI 0.02, 0.69). Agreement and reliability indices improved as diagnostic confidence increased. Reliability was fair among clinicians from different backgrounds when diagnosing LBLP but improved substantially with high confidence in clinical diagnosis.

How do swine practitioners and veterinary pathologists arrive at a diagnosis of Clostridium perfringens type A enteritis in neonatal piglets?

PubMed

Chan, Gloria; Farzan, Abdolvahab; Prescott, John F; Friendship, Robert

2013-05-01

A questionnaire was administered to 22 veterinary practitioners and 17 veterinary pathologists to investigate the methods used for diagnosis of Clostridium perfringens type A enteritis in neonatal pigs. Practitioners generally diagnosed C. perfringens type A associated enteritis by age of onset of diarrhea (between 1 to 7 days of age). Most practitioners (95%) were moderately to very confident in their diagnosis. Pathologists generally diagnosed C. perfringens type A associated enteritis by combinations of isolation of the organism, genotyping or detecting the toxins of the organism, and ruling out other pathogens through histopathology. Almost half (41%) of the pathologists were not confident of their diagnosis. This study reports that the current diagnostic method for C. perfringens type A enteritis is not specific, and although many pathologists expressed reservations about making a diagnosis of C. perfringens type A enteritis, most practitioners were confident in their diagnosis, even though reported clinical signs of clostridial diarrhea are similar to those of a number of other enteric diseases.

Application of Advanced Laser Diagnostics to High Impact Technologies. Delivery Order 0001: Laser Diagnostics Applications

DTIC Science & Technology

2011-02-01

identified the hysteresis property of this flame system; this was later confirmed by experiments. For the given flow conditions, the flame system can......transport properties . This concept increased the computational speed by a factor of five for a 208-species mechanism and is expected to have even higher

The Application of Strength of Association Statistics to the Item Analysis of an In-Training Examination in Diagnostic Radiology.

ERIC Educational Resources Information Center

Diamond, James J.; McCormick, Janet

1986-01-01

Using item responses from an in-training examination in diagnostic radiology, the application of a strength of association statistic to the general problem of item analysis is illustrated. Criteria for item selection, general issues of reliability, and error of measurement are discussed. (Author/LMO)

Rocket Engine Plume Diagnostics at Stennis Space Center

NASA Technical Reports Server (NTRS)

Tejwani, Gopal D.; Langford, Lester A.; VanDyke, David B.; McVay, Gregory P.; Thurman, Charles C.

2003-01-01

The Stennis Space Center has been at the forefront of development and application of exhaust plume spectroscopy to rocket engine health monitoring since 1989. Various spectroscopic techniques, such as emission, absorption, FTIR, LIF, and CARS, have been considered for application at the engine test stands. By far the most successful technology h a been exhaust plume emission spectroscopy. In particular, its application to the Space Shuttle Main Engine (SSME) ground test health monitoring has been invaluable in various engine testing and development activities at SSC since 1989. On several occasions, plume diagnostic methods have successfully detected a problem with one or more components of an engine long before any other sensor indicated a problem. More often, they provide corroboration for a failure mode, if any occurred during an engine test. This paper gives a brief overview of our instrumentation and computational systems for rocket engine plume diagnostics at SSC. Some examples of successful application of exhaust plume spectroscopy (emission as well as absorption) to the SSME testing are presented. Our on-going plume diagnostics technology development projects and future requirements are discussed.

Post-traumatic stress disorder in adolescents after a hurricane.

PubMed

Garrison, C Z; Weinrich, M W; Hardin, S B; Weinrich, S; Wang, L

1993-10-01

A school-based study conducted in 1990, 1 year after Hurricane Hugo, investigated the frequency and correlates of post-traumatic stress disorder (PTSD) in 1,264 adolescents aged 11-17 years residing in selected South Carolina communities. Data were collected via a 174-item self-administered questionnaire that included a PTSD symptom scale. A computer algorithm that applied decision rules of the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised to the symptoms reported was used to assign a diagnosis of PTSD and to designate the number of individuals who met the reexperiencing (20%), avoidance (9%), and arousal (18%) criteria. Rates of PTSD were lowest in black males (1.5%) and higher, but similar, in the remaining groups (3.8-6.2%). Results from a multivariable logistic model indicated that exposure to the hurricane (odds ratio (OR) = 1.26, 95% confidence interval 1.13-1.41), experiencing other violent traumatic events (OR = 2.46, 95% confidence interval 1.75-3.44), being white (OR = 2.03, 95% confidence interval 1.12-3.69) and being female (OR = 2.17, 95% confidence interval 1.15-4.10) were significant correlates of PTSD.

Pharmacometabolomics Informs Quantitative Radiomics for Glioblastoma Diagnostic Innovation.

PubMed

Katsila, Theodora; Matsoukas, Minos-Timotheos; Patrinos, George P; Kardamakis, Dimitrios

2017-08-01

Applications of omics systems biology technologies have enormous promise for radiology and diagnostics in surgical fields. In this context, the emerging fields of radiomics (a systems scale approach to radiology using a host of technologies, including omics) and pharmacometabolomics (use of metabolomics for patient and disease stratification and guiding precision medicine) offer much synergy for diagnostic innovation in surgery, particularly in neurosurgery. This synthesis of omics fields and applications is timely because diagnostic accuracy in central nervous system tumors still challenges decision-making. Considering the vast heterogeneity in brain tumors, disease phenotypes, and interindividual variability in surgical and chemotherapy outcomes, we believe that diagnostic accuracy can be markedly improved by quantitative radiomics coupled to pharmacometabolomics and related health information technologies while optimizing economic costs of traditional diagnostics. In this expert review, we present an innovation analysis on a systems-level multi-omics approach toward diagnostic accuracy in central nervous system tumors. For this, we suggest that glioblastomas serve as a useful application paradigm. We performed a literature search on PubMed for articles published in English between 2006 and 2016. We used the search terms "radiomics," "glioblastoma," "biomarkers," "pharmacogenomics," "pharmacometabolomics," "pharmacometabonomics/pharmacometabolomics," "collaborative informatics," and "precision medicine." A list of the top 4 insights we derived from this literature analysis is presented in this study. For example, we found that (i) tumor grading needs to be better refined, (ii) diagnostic precision should be improved, (iii) standardization in radiomics is lacking, and (iv) quantitative radiomics needs to prove clinical implementation. We conclude with an interdisciplinary call to the metabolomics, pharmacy/pharmacology, radiology, and surgery communities that pharmacometabolomics coupled to information technologies (chemoinformatics tools, databases, collaborative systems) can inform quantitative radiomics, thus translating Big Data and information growth to knowledge growth, rational drug development and diagnostics innovation for glioblastomas, and possibly in other brain tumors.

Motivation and satisfaction among community health workers administering rapid diagnostic tests for malaria in Western Kenya.

PubMed

Winn, Laura K; Lesser, Adriane; Menya, Diana; Baumgartner, Joy N; Kipkoech Kirui, Joseph; Saran, Indrani; Prudhomme-O'Meara, Wendy

2018-06-01

The continued success of community case management (CCM) programs in low-resource settings depends on the ability of these programs to retain the community health workers (CHWs), many of whom are volunteers, and maintain their high-quality performance. This study aims to identify factors related to the motivation and satisfaction of CHWs working in a malaria CCM program in two sub-counties in Western Kenya. We interviewed 70 CHWs who were trained to administer malaria rapid diagnostic tests as part of a broader study evaluating a malaria CCM program. We identified factors related to CHWs' motivation and their satisfaction with participation in the program, as well as the feasibility of program scale-up. We used principal components analysis to develop an overall CHW satisfaction score and assessed associations between this score and individual CHW characteristics as well as their experiences in the program. The majority of CHWs reported that they were motivated to perform their role in this malaria CCM program by a personal desire to help their community (69%). The most common challenge CHWs reported was a lack of community understanding about malaria diagnostic testing and CHWs' role in the program (39%). Most CHWs (89%) reported that their involvement in the diagnostic testing intervention had either a neutral or a net positive effect on their other CHW activities, including improving skills applicable to other tasks. CHWs who said they strongly agreed with the statement that their work with the malaria program was appreciated by the community had a 0.76 standard deviation (SD) increase in their overall satisfaction score (95% confidence interval CI = 0.10-1.24, P  = 0.03). Almost all CHWs (99%) strongly agreed that they wanted to continue their role in the malaria program. Overall, CHWs reported high satisfaction with their role in community-based malaria diagnosis, though they faced challenges primarily related to community understanding and appreciation of the services they provided. CHWs' perceptions that the malaria program generally did not interfere with their other activities is encouraging for the sustainability and scale-up of similar CHW programs.

Imaging of neurodegenerative cognitive and behavioral disorders: practical considerations for dementia clinical practice.

PubMed

Atri, Alireza

2016-01-01

This chapter reviews clinical applications and imaging findings useful in medical practice relating to neurodegenerative cognitive/dementing disorders. The preponderance of evidence and consensus guidelines support an essential role of multitiered neuroimaging in the evaluation and management of neurodegenerative cognitive/dementia syndrome that range in severity from mild impairments to frank dementia. Additionally, imaging features are incorporated in updated clinical and research diagnostic criteria for most dementias, including Alzheimer's disease (AD), Dementia with Lewy bodies (DLB), Frontotemporal Lobar Degenerations/Frontotemporal Dementia (FTD), and Vascular Cognitive Impairment (VCI). Best clinical practices dictate that structural imaging, preferably with magnetic resonance imaging (MRI) when possible and computed tomography when not, be obtained as a first-tier approach during the course of a thorough clinical evaluation to improve diagnostic confidence and assess for nonneurodegenerative treatable conditions that may cause or substantially contribute to cognitive/behavioral symptoms or which may dictate a substantial change in management. These conditions include less common structural (e.g., mass lesions such as tumors and hematomas; normal-pressure hydrocephalus), inflammatory, autoimmune and infectious conditions, and more common comorbid contributing conditions (e.g., vascular cerebral injury causing leukoaraiosis, infarcts, or microhemorrhages) that can produce a mixed dementia syndrome. When, after appropriate clinical, cognitive/neuropsychologic, and structural neuroimaging assessment, a dementia specialist remains in doubt regarding etiology and appropriate management, second-tier imaging with molecular methods, preferably with fluorodexoyglucose positron emission tomography (PET) (or single-photon emission computed tomography if PET is unavailable) can provide more diagnostic specificity (e.g., help differentiate between atypical AD and FTD as the etiology for a frontal/dysexecutive syndrome). The potential clinical utility of other promising methods, whether already approved for use (e.g., amyloid PET) or as yet only used in research (e.g., tau PET, functional MRI, diffusor tensor imaging), remains to be proven for widespread use in community practice. However, these constitute unreimbursed third-tier options that merit further study for clinical and cost-effective utility. In the future, combination use of imaging methods will likely improve diagnostic accuracy. © 2016 Elsevier B.V. All rights reserved.

Motivation and satisfaction among community health workers administering rapid diagnostic tests for malaria in Western Kenya

PubMed Central

Winn, Laura K; Lesser, Adriane; Menya, Diana; Baumgartner, Joy N; Kipkoech Kirui, Joseph; Saran, Indrani; Prudhomme-O’Meara, Wendy

2018-01-01

Background The continued success of community case management (CCM) programs in low-resource settings depends on the ability of these programs to retain the community health workers (CHWs), many of whom are volunteers, and maintain their high-quality performance. This study aims to identify factors related to the motivation and satisfaction of CHWs working in a malaria CCM program in two sub-counties in Western Kenya. Methods We interviewed 70 CHWs who were trained to administer malaria rapid diagnostic tests as part of a broader study evaluating a malaria CCM program. We identified factors related to CHWs’ motivation and their satisfaction with participation in the program, as well as the feasibility of program scale-up. We used principal components analysis to develop an overall CHW satisfaction score and assessed associations between this score and individual CHW characteristics as well as their experiences in the program. Results The majority of CHWs reported that they were motivated to perform their role in this malaria CCM program by a personal desire to help their community (69%). The most common challenge CHWs reported was a lack of community understanding about malaria diagnostic testing and CHWs’ role in the program (39%). Most CHWs (89%) reported that their involvement in the diagnostic testing intervention had either a neutral or a net positive effect on their other CHW activities, including improving skills applicable to other tasks. CHWs who said they strongly agreed with the statement that their work with the malaria program was appreciated by the community had a 0.76 standard deviation (SD) increase in their overall satisfaction score (95% confidence interval CI = 0.10-1.24, P = 0.03). Almost all CHWs (99%) strongly agreed that they wanted to continue their role in the malaria program. Conclusions Overall, CHWs reported high satisfaction with their role in community-based malaria diagnosis, though they faced challenges primarily related to community understanding and appreciation of the services they provided. CHWs’ perceptions that the malaria program generally did not interfere with their other activities is encouraging for the sustainability and scale-up of similar CHW programs. PMID:29497500

Reliability of Chinese medicine diagnostic variables in the examination of patients with osteoarthritis of the knee.

PubMed

Hua, Bin; Abbas, Estelle; Hayes, Alan; Ryan, Peter; Nelson, Lisa; O'Brien, Kylie

2012-11-01

Chinese medicine (CM) has its own diagnostic indicators that are used as evidence of change in a patient's condition. The majority of studies investigating efficacy of Chinese herbal medicine (CHM) have utilized biomedical diagnostic endpoints. For CM clinical diagnostic variables to be incorporated into clinical trial designs, there would need to be evidence that these diagnostic variables are reliable. Previous studies have indicated that the reliability of CM syndrome diagnosis is variable. Little information is known about where the variability stems from--the basic data collection level or the synthesis of diagnostic data, or both. No previous studies have investigated systematically the reliability of all four diagnostic methods used in the CM diagnostic process (Inquiry, Inspection, Auscultation/Olfaction, and Palpation). The objective of this study was to assess the inter-rater reliability of data collected using the four diagnostic methods of CM in Australian patients with knee osteoarthritis (OA), in order to investigate if CM variables could be used with confidence as diagnostic endpoints in a clinical trial investigating the efficacy of a CHM in treating OA. An inter-rater reliability study was conducted as a substudy of a clinical trial investigating the treatment of knee OA with Chinese herbal medicine. Two (2) experienced CM practitioners conducted a CM examination separately, within 2 hours of each other, in 40 participants. A CM assessment form was utilized to record the diagnostic data. Cohen's κ coefficient was used as a measure of the level of agreement between 2 practitioners. There was a relatively good level of agreement for Inquiry and Auscultation variables, and, in general, a low level of agreement for (visual) Inspection and Palpation variables. There was variation in the level of agreement between 2 practitioners on clinical information collected using the Four Diagnostic Methods of a CM examination. Some aspects of CM diagnosis appear to be reliable, while others are not. Based on these results, it was inappropriate to use CM diagnostic variables as diagnostic endpoints in the main study, which was an investigation of efficacy of CHM treatment of knee OA.

Additive value of non-contrast MRA in the preoperative evaluation of potential liver donors.

PubMed

Luk, Lyndon; Shenoy-Bhangle, Anuradha S; Jimenez, Guillermo; Ahmed, Firas S; Prince, Martin R; Samstein, Benjamin; Hecht, Elizabeth M

The purpose of this study is to compare diagnostic quality, inter-observer variability and agreement of non-contrast enhanced MRA (NC-MRA) with contrast-enhanced MRA (CE-MRA) in the evaluation of hepatic arterial anatomy. 20 potential liver donors were included in this retrospective study. NC-MRA, CE-MRA and combined data sets were randomized and reviewed by two readers. Reference standard was consensus by two senior radiologists using all data including CTA. There was no difference in IQ or diagnostic confidence between NC-MRA, CE-MRA or combined data for either reader but the arterial origin of segment IV was successfully identified on NC-MRA when CE-MRA was suboptimal. Copyright © 2016 Elsevier Inc. All rights reserved.

4D co-registration of X-ray and MR-mammograms: initial clinical results and potential incremental diagnostic value.

PubMed

Dietzel, Matthias; Hopp, Torsten; Ruiter, Nicole V; Kaiser, Clemens G; Kaiser, Werner A; Baltzer, Pascal A

2015-01-01

4D co-registration of X-ray- and MR-mammograms (XM and MM) is a new method of image fusion. The present study aims to evaluate its clinical feasibility, radiological accuracy, and potential clinical value. XM and MM of 25 patients were co-registered. Results were evaluated by a blinded reader. Precision of the 4D co-registration was "very good" (mean-score [ms]=7), and lesions were "easier to delineate" (ms=5). In 88.8%, "relevant additional diagnostic information" was present, accounting for a more "confident diagnosis" in 76% (ms=5). 4D co-registration is feasible, accurate, and of potential clinical value. Copyright © 2015 Elsevier Inc. All rights reserved.

Increasing Scientific Confidence in Adverse Outcome Pathways: Application of Tailored Bradford-Hill Considerations for Evaluating Weight of Evidence.

PubMed

Becker, Richard A; Ankley, Gerald T; Edwards, Stephen W; Kennedy, Sean W; Linkov, Igor; Meek, Bette; Sachana, Magdalini; Segner, Helmut; Van Der Burg, Bart; Villeneuve, Daniel L; Watanabe, Haruna; Barton-Maclaren, Tara S

2015-08-01

Systematic consideration of scientific support is a critical element in developing and, ultimately, using adverse outcome pathways (AOPs) for various regulatory applications. Though weight of evidence (WoE) analysis has been proposed as a basis for assessment of the maturity and level of confidence in an AOP, methodologies and tools are still being formalized. The Organization for Economic Co-operation and Development (OECD) Users' Handbook Supplement to the Guidance Document for Developing and Assessing AOPs (OECD 2014a; hereafter referred to as the OECD AOP Handbook) provides tailored Bradford-Hill (BH) considerations for systematic assessment of confidence in a given AOP. These considerations include (1) biological plausibility and (2) empirical support (dose-response, temporality, and incidence) for Key Event Relationships (KERs), and (3) essentiality of key events (KEs). Here, we test the application of these tailored BH considerations and the guidance outlined in the OECD AOP Handbook using a number of case examples to increase experience in more transparently documenting rationales for assigned levels of confidence to KEs and KERs, and to promote consistency in evaluation within and across AOPs. The major lessons learned from experience are documented, and taken together with the case examples, should contribute to better common understanding of the nature and form of documentation required to increase confidence in the application of AOPs for specific uses. Based on the tailored BH considerations and defining questions, a prototype quantitative model for assessing the WoE of an AOP using tools of multi-criteria decision analysis (MCDA) is described. The applicability of the approach is also demonstrated using the case example aromatase inhibition leading to reproductive dysfunction in fish. Following the acquisition of additional experience in the development and assessment of AOPs, further refinement of parameterization of the model through expert elicitation is recommended. Overall, the application of quantitative WoE approaches hold promise to enhance the rigor, transparency and reproducibility for AOP WoE determinations and may play an important role in delineating areas where research would have the greatest impact on improving the overall confidence in the AOP. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Contemporary instrumentation and application of charge exchange neutral particle diagnostics in magnetic fusion energy experiments.

PubMed

Medley, S S; Donné, A J H; Kaita, R; Kislyakov, A I; Petrov, M P; Roquemore, A L

2008-01-01

An overview of the developments postcirca 1980s in the instrumentation and application of charge exchange neutral particle diagnostics on magnetic fusion energy experiments is presented. First, spectrometers that employ only electric fields and hence provide ion energy resolution but not mass resolution are discussed. Next, spectrometers that use various geometrical combinations of both electric and magnetic fields to provide both energy and mass resolutions are reviewed. Finally, neutral particle diagnostics based on utilization of time-of-flight techniques are presented.

78 FR 54487 - Abbott Laboratories; Diagnostic-Hematology; Including On-Site Leased Workers From Manpower...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-04

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-82,379] Abbott Laboratories... February 22, 2013, applicable to workers of Abbott Laboratories, Diagnostic--Hematology division, including... Clara, California location of Abbott Laboratories, Diagnostic--Hematology Division. The Department has...

76 FR 2144 - Quest Diagnostics, Inc. Information Technology Help Desk Services Including On-Site Leased...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-12

.... Information Technology Help Desk Services Including On-Site Leased Workers From Modis, West Norriton, PA..., applicable to workers of Quest Diagnostics, Inc., Information Technology Help Desk Services, West Norriton... Quest Diagnostics, Inc., Information Technology Help Desk [[Page 2145

A Teaching Simulation Is Effective in Improving Athletic Training Students' Football Helmet Facemask Removal Clinical Skills and Confidence

ERIC Educational Resources Information Center

Popp, Jennifer K.; Walker, Stacy E.

2017-01-01

Context: Patient encounters related to acute care skills rarely occur in clinical education, leaving a potential gap in students' skills and confidence. Objective: Investigate the effects of an acute care simulation requiring football helmet facemask removal on clinical skill application and confidence in athletic training students. Design:…

Confidence intervals from single observations in forest research

Treesearch

Harry T. Valentine; George M. Furnival; Timothy G. Gregoire

1991-01-01

A procedure for constructing confidence intervals and testing hypothese from a single trial or observation is reviewed. The procedure requires a prior, fixed estimate or guess of the outcome of an experiment or sampling. Two examples of applications are described: a confidence interval is constructed for the expected outcome of a systematic sampling of a forested tract...

Estimating a test's accuracy using tailored meta-analysis-How setting-specific data may aid study selection.

PubMed

Willis, Brian H; Hyde, Christopher J

2014-05-01

To determine a plausible estimate for a test's performance in a specific setting using a new method for selecting studies. It is shown how routine data from practice may be used to define an "applicable region" for studies in receiver operating characteristic space. After qualitative appraisal, studies are selected based on the probability that their study accuracy estimates arose from parameters lying in this applicable region. Three methods for calculating these probabilities are developed and used to tailor the selection of studies for meta-analysis. The Pap test applied to the UK National Health Service (NHS) Cervical Screening Programme provides a case example. The meta-analysis for the Pap test included 68 studies, but at most 17 studies were considered applicable to the NHS. For conventional meta-analysis, the sensitivity and specificity (with 95% confidence intervals) were estimated to be 72.8% (65.8, 78.8) and 75.4% (68.1, 81.5) compared with 50.9% (35.8, 66.0) and 98.0% (95.4, 99.1) from tailored meta-analysis using a binomial method for selection. Thus, for a cervical intraepithelial neoplasia (CIN) 1 prevalence of 2.2%, the post-test probability for CIN 1 would increase from 6.2% to 36.6% between the two methods of meta-analysis. Tailored meta-analysis provides a method for augmenting study selection based on the study's applicability to a setting. As such, the summary estimate is more likely to be plausible for a setting and could improve diagnostic prediction in practice. Copyright © 2014 Elsevier Inc. All rights reserved.

Fusing Symbolic and Numerical Diagnostic Computations

NASA Technical Reports Server (NTRS)

James, Mark

2007-01-01

X-2000 Anomaly Detection Language denotes a developmental computing language, and the software that establishes and utilizes the language, for fusing two diagnostic computer programs, one implementing a numerical analysis method, the other implementing a symbolic analysis method into a unified event-based decision analysis software system for realtime detection of events (e.g., failures) in a spacecraft, aircraft, or other complex engineering system. The numerical analysis method is performed by beacon-based exception analysis for multi-missions (BEAMs), which has been discussed in several previous NASA Tech Briefs articles. The symbolic analysis method is, more specifically, an artificial-intelligence method of the knowledge-based, inference engine type, and its implementation is exemplified by the Spacecraft Health Inference Engine (SHINE) software. The goal in developing the capability to fuse numerical and symbolic diagnostic components is to increase the depth of analysis beyond that previously attainable, thereby increasing the degree of confidence in the computed results. In practical terms, the sought improvement is to enable detection of all or most events, with no or few false alarms.

Antibody-mediated rejection of the lung: A consensus report of the International Society for Heart and Lung Transplantation.

PubMed

Levine, Deborah J; Glanville, Allan R; Aboyoun, Christina; Belperio, John; Benden, Christian; Berry, Gerald J; Hachem, Ramsey; Hayes, Don; Neil, Desley; Reinsmoen, Nancy L; Snyder, Laurie D; Sweet, Stuart; Tyan, Dolly; Verleden, Geert; Westall, Glen; Yusen, Roger D; Zamora, Martin; Zeevi, Adriana

2016-04-01

Antibody-mediated rejection (AMR) is a recognized cause of allograft dysfunction in lung transplant recipients. Unlike AMR in other solid-organ transplant recipients, there are no standardized diagnostic criteria or an agreed-upon definition. Hence, a working group was created by the International Society for Heart and Lung Transplantation with the aim of determining criteria for pulmonary AMR and establishing a definition. Diagnostic criteria and a working consensus definition were established. Key diagnostic criteria include the presence of antibodies directed toward donor human leukocyte antigens and characteristic lung histology with or without evidence of complement 4d within the graft. Exclusion of other causes of allograft dysfunction increases confidence in the diagnosis but is not essential. Pulmonary AMR may be clinical (allograft dysfunction which can be asymptomatic) or sub-clinical (normal allograft function). This consensus definition will have clinical, therapeutic and research implications. Copyright © 2016 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Patterns of diagnostic imaging and associated radiation exposure among long-term survivors of young adult cancer: a population-based cohort study.

PubMed

Daly, Corinne; Urbach, David R; Stukel, Thérèse A; Nathan, Paul C; Deitel, Wayne; Paszat, Lawrence F; Wilton, Andrew S; Baxter, Nancy N

2015-09-03

Survivors of young adult malignancies are at risk of accumulated exposures to radiation from repetitive diagnostic imaging. We designed a population-based cohort study to describe patterns of diagnostic imaging and cumulative diagnostic radiation exposure among survivors of young adult cancer during a survivorship time period where surveillance imaging is not typically warranted. Young adults aged 20-44 diagnosed with invasive malignancy in Ontario from 1992-1999 who lived at least 5 years from diagnosis were identified using the Ontario Cancer Registry and matched 5 to 1 to randomly selected cancer-free persons. We determined receipt of 5 modalities of diagnostic imaging and associated radiation dose received by survivors and controls from years 5-15 after diagnosis or matched referent date through administrative data. Matched pairs were censored six months prior to evidence of recurrence. 20,911 survivors and 104,524 controls had a median of 13.5 years observation. Survivors received all modalities of diagnostic imaging at significantly higher rates than controls. Survivors received CT at a 3.49-fold higher rate (95% Confidence Interval [CI]:3.37, 3.62) than controls in years 5 to 15 after diagnosis. Survivors received a mean radiation dose of 26 miliSieverts solely from diagnostic imaging in the same time period, a 4.57-fold higher dose than matched controls (95% CI: 4.39, 4.81). Long-term survivors of young adult cancer have a markedly higher rate of diagnostic imaging over time than matched controls, imaging associated with substantial radiation exposure, during a time period when surveillance is not routinely recommended.

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.

Comparison of Established Diagnostic Methodologies and a Novel Bacterial smpB Real-Time PCR Assay for Specific Detection of Haemophilus influenzae Isolates Associated with Respiratory Tract Infections.

PubMed

Reddington, Kate; Schwenk, Stefan; Tuite, Nina; Platt, Gareth; Davar, Danesh; Coughlan, Helena; Personne, Yoann; Gant, Vanya; Enne, Virve I; Zumla, Alimuddin; Barry, Thomas

2015-09-01

Haemophilus influenzae is a significant causative agent of respiratory tract infections (RTI) worldwide. The development of a rapid H. influenzae diagnostic assay that would allow for the implementation of infection control measures and also improve antimicrobial stewardship for patients is required. A number of nucleic acid diagnostics approaches that detect H. influenzae in RTIs have been described in the literature; however, there are reported specificity and sensitivity limitations for these assays. In this study, a novel real-time PCR diagnostic assay targeting the smpB gene was designed to detect all serogroups of H. influenzae. The assay was validated using a panel of well-characterized Haemophilus spp. Subsequently, 44 Haemophilus clinical isolates were collected, and 36 isolates were identified as H. influenzae using a gold standard methodology that combined the results of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and a fucK diagnostic assay. Using the novel smpB diagnostic assay, 100% concordance was observed with the gold standard, demonstrating a sensitivity of 100% (95% confidence interval [CI], 90.26% to 100.00%) and a specificity of 100% (95% CI, 63.06% to 100.00%) when used on clinical isolates. To demonstrate the clinical utility of the diagnostic assay presented, a panel of lower RTI samples (n = 98) were blindly tested with the gold standard and smpB diagnostic assays. The results generated were concordant for 94/98 samples tested, demonstrating a sensitivity of 90.91% (95% CI, 78.33% to 97.47%) and a specificity of 100% (95% CI, 93.40% to 100.00%) for the novel smpB assay when used directly on respiratory specimens. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Comparison of Established Diagnostic Methodologies and a Novel Bacterial smpB Real-Time PCR Assay for Specific Detection of Haemophilus influenzae Isolates Associated with Respiratory Tract Infections

PubMed Central

Reddington, Kate; Schwenk, Stefan; Tuite, Nina; Platt, Gareth; Davar, Danesh; Coughlan, Helena; Personne, Yoann; Gant, Vanya; Enne, Virve I.; Zumla, Alimuddin

2015-01-01

Haemophilus influenzae is a significant causative agent of respiratory tract infections (RTI) worldwide. The development of a rapid H. influenzae diagnostic assay that would allow for the implementation of infection control measures and also improve antimicrobial stewardship for patients is required. A number of nucleic acid diagnostics approaches that detect H. influenzae in RTIs have been described in the literature; however, there are reported specificity and sensitivity limitations for these assays. In this study, a novel real-time PCR diagnostic assay targeting the smpB gene was designed to detect all serogroups of H. influenzae. The assay was validated using a panel of well-characterized Haemophilus spp. Subsequently, 44 Haemophilus clinical isolates were collected, and 36 isolates were identified as H. influenzae using a gold standard methodology that combined the results of matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) and a fucK diagnostic assay. Using the novel smpB diagnostic assay, 100% concordance was observed with the gold standard, demonstrating a sensitivity of 100% (95% confidence interval [CI], 90.26% to 100.00%) and a specificity of 100% (95% CI, 63.06% to 100.00%) when used on clinical isolates. To demonstrate the clinical utility of the diagnostic assay presented, a panel of lower RTI samples (n = 98) were blindly tested with the gold standard and smpB diagnostic assays. The results generated were concordant for 94/98 samples tested, demonstrating a sensitivity of 90.91% (95% CI, 78.33% to 97.47%) and a specificity of 100% (95% CI, 93.40% to 100.00%) for the novel smpB assay when used directly on respiratory specimens. PMID:26109443

Patient navigation significantly reduces delays in breast cancer diagnosis in the District of Columbia.

PubMed

Hoffman, Heather J; LaVerda, Nancy L; Young, Heather A; Levine, Paul H; Alexander, Lisa M; Brem, Rachel; Caicedo, Larisa; Eng-Wong, Jennifer; Frederick, Wayne; Funderburk, William; Huerta, Elmer; Swain, Sandra; Patierno, Steven R

2012-10-01

Patient Navigation (PN) originated in Harlem as an intervention to help poor women overcome access barriers to timely breast cancer treatment. Despite rapid, nationally widespread adoption of PN, empirical evidence on its effectiveness is lacking. In 2005, National Cancer Institute initiated a multicenter PN Research Program (PNRP) to measure PN effectiveness for several cancers. The George Washington Cancer Institute, a project participant, established District of Columbia (DC)-PNRP to determine PN's ability to reduce breast cancer diagnostic time (number of days from abnormal screening to definitive diagnosis). A total of 2,601 women (1,047 navigated; 1,554 concurrent records-based nonnavigated) were examined for breast cancer from 2006 to 2010 at 9 hospitals/clinics in DC. Analyses included only women who reached complete diagnostic resolution. Differences in diagnostic time between navigation groups were tested with ANOVA models including categorical demographic and treatment variables. Log transformations normalized diagnostic time. Geometric means were estimated and compared using Tukey-Kramer P value adjustments. Average-geometric mean [95% confidence interval (CI)]-diagnostic time (days) was significantly shorter for navigated, 25.1 (21.7, 29.0), than nonnavigated women, 42.1 (35.8, 49.6). Subanalyses revealed significantly shorter average diagnostic time for biopsied navigated women, 26.6 (21.8, 32.5) than biopsied nonnavigated women, 57.5 (46.3, 71.5). Among nonbiopsied women, diagnostic time was shorter for navigated, 27.2 (22.8, 32.4), than nonnavigated women, 34.9 (29.2, 41.7), but not statistically significant. Navigated women, especially those requiring biopsy, reached their diagnostic resolution significantly faster than nonnavigated women. Results support previous findings of PN's positive influence on health care. PN should be a reimbursable expense to assure continuation of PN programs. 2012 AACR

Influence of companion diagnostics on efficacy and safety of targeted anti-cancer drugs: systematic review and meta-analyses

PubMed Central

Ocana, Alberto; Ethier, Josee-Lyne; Díez-González, Laura; Corrales-Sánchez, Verónica; Srikanthan, Amirrtha; Gascón-Escribano, María J.; Templeton, Arnoud J.; Vera-Badillo, Francisco; Seruga, Bostjan; Niraula, Saroj; Pandiella, Atanasio; Amir, Eitan

2015-01-01

Background Companion diagnostics aim to identify patients that will respond to targeted therapies, therefore increasing the clinical efficacy of such drugs. Less is known about their influence on safety and tolerability of targeted anti-cancer agents. Methods and findings Randomized trials evaluating targeted agents for solid tumors approved by the US Food and Drug Administration since year 2000 were assessed. Odds ratios (OR) and and 95% confidence intervals (CI) were computed for treatment-related death, treatment-discontinuation related to toxicity and occurrence of any grade 3/4 adverse events (AEs). The 12 most commonly reported individual AEs were also explored. ORs were pooled in a meta-analysis. Analysis comprised 41 trials evaluating 28 targeted agents. Seventeen trials (41%) utilized companion diagnostics. Compared to control groups, targeted drugs in experimental arms were associated with increased odds of treatment discontinuation, grade 3/4 AEs, and toxic death irrespective of whether they utilized companion diagnostics or not. Compared to drugs without available companion diagnostics, agents with companion diagnostics had a lower magnitude of increased odds of treatment discontinuation (OR = 1.12 versus 1.65, p < 0.001) and grade 3/4 AEs (OR = 1.09 versus 2.10, p < 0.001), but no difference in risk of toxic death (OR = 1.40 versus 1.27, p = 0.69). Differences between agents with and without companion diagnostics were greatest for diarrhea (OR = 1.29 vs. 2.43, p < 0.001), vomiting (OR = 0.86 vs. 1.44, p = 0.005), cutaneous toxicity (OR = 1.82 vs. 3.88, p < 0.001) and neuropathy (OR = 0.64 vs. 1.60, p < 0.001). Conclusions Targeted drugs with companion diagnostics are associated with improved safety, and tolerability. Differences were most marked for gastrointestinal, cutaneous and neurological toxicity. PMID:26446908

Influence of companion diagnostics on efficacy and safety of targeted anti-cancer drugs: systematic review and meta-analyses.

PubMed

Ocana, Alberto; Ethier, Josee-Lyne; Díez-González, Laura; Corrales-Sánchez, Verónica; Srikanthan, Amirrtha; Gascón-Escribano, María J; Templeton, Arnoud J; Vera-Badillo, Francisco; Seruga, Bostjan; Niraula, Saroj; Pandiella, Atanasio; Amir, Eitan

2015-11-24

Companion diagnostics aim to identify patients that will respond to targeted therapies, therefore increasing the clinical efficacy of such drugs. Less is known about their influence on safety and tolerability of targeted anti-cancer agents. Randomized trials evaluating targeted agents for solid tumors approved by the US Food and Drug Administration since year 2000 were assessed. Odds ratios (OR) and and 95% confidence intervals (CI) were computed for treatment-related death, treatment-discontinuation related to toxicity and occurrence of any grade 3/4 adverse events (AEs). The 12 most commonly reported individual AEs were also explored. ORs were pooled in a meta-analysis. Analysis comprised 41 trials evaluating 28 targeted agents. Seventeen trials (41%) utilized companion diagnostics. Compared to control groups, targeted drugs in experimental arms were associated with increased odds of treatment discontinuation, grade 3/4 AEs, and toxic death irrespective of whether they utilized companion diagnostics or not. Compared to drugs without available companion diagnostics, agents with companion diagnostics had a lower magnitude of increased odds of treatment discontinuation (OR = 1.12 vs. 1.65, p < 0.001) and grade 3/4 AEs (OR = 1.09 vs. 2.10, p < 0.001), but no difference in risk of toxic death (OR = 1.40 vs. 1.27, p = 0.69). Differences between agents with and without companion diagnostics were greatest for diarrhea (OR = 1.29 vs. 2.43, p < 0.001), vomiting (OR = 0.86 vs. 1.44, p = 0.005), cutaneous toxicity (OR = 1.82 vs. 3.88, p < 0.001) and neuropathy (OR = 0.64 vs. 1.60, p < 0.001). Targeted drugs with companion diagnostics are associated with improved safety, and tolerability. Differences were most marked for gastrointestinal, cutaneous and neurological toxicity.

Saliva diagnostics – Current views and directions

PubMed Central

Kaczor-Urbanowicz, Karolina Elżbieta; Martin Carreras-Presas, Carmen; Aro, Katri; Tu, Michael; Wong, David TW

2016-01-01

In this review, we provide an update on the current and future applications of saliva for diagnostic purposes. There are many advantages of using saliva as a biofluid. Its collection is fast, easy, inexpensive, and non-invasive. In addition, saliva, as a “mirror of the body,” can reflect the physiological and pathological state of the body. Therefore, it serves as a diagnostic and monitoring tool in many fields of science such as medicine, dentistry, and pharmacotherapy. Introduced in 2008, the term “Salivaomics” aimed to highlight the rapid development of knowledge about various “omics” constituents of saliva, including: proteome, transcriptome, micro-RNA, metabolome, and microbiome. In the last few years, researchers have developed new technologies and validated a wide range of salivary biomarkers that will soon make the use of saliva a clinical reality. However, a great need still exists for convenient and accurate point-of-care devices that can serve as a non-invasive diagnostic tool. In addition, there is an urgent need to decipher the scientific rationale and mechanisms that convey systemic diseases to saliva. Another promising technology called liquid biopsy enables detection of circulating tumor cells (CTCs) and fragments of tumor DNA in saliva, thus enabling non-invasive early detection of various cancers. The newly developed technology—electric field-induced release and measurement (EFIRM) provides near perfect detection of actionable mutations in lung cancer patients. These recent advances widened the salivary diagnostic approach from the oral cavity to the whole physiological system, and thus point towards a promising future of salivary diagnostics for personalized individual medicine applications including clinical decisions and post-treatment outcome predictions. Impact statement The purpose of this mini-review is to make an update about the present and future applications of saliva as a diagnostic biofluid in many fields of science such as dentistry, medicine and pharmacotherapy. Using saliva as a fluid for diagnostic purposes would be a huge breakthrough for both patients and healthcare providers since saliva collection is easy, non-invasive and inexpensive. We will go through the current main diagnostic applications of saliva, and provide a highlight on the emerging, newly developing technologies and tools for cancer screening, detection and monitoring. PMID:27903834

Useful diagnostic biometabolic data obtained by PET/CT and MR fusion imaging using open source software.

PubMed

Antonica, Filippo; Asabella, Artor Niccoli; Ferrari, Cristina; Rubini, Domenico; Notaristefano, Antonio; Nicoletti, Adriano; Altini, Corinna; Merenda, Nunzio; Mossa, Emilio; Guarini, Attilio; Rubini, Giuseppe

2014-01-01

In the last decade numerous attempts were considered to co-register and integrate different imaging data. Like PET/CT the integration of PET to MR showed great interest. PET/MR scanners are recently tested on different distrectual or systemic pathologies. Unfortunately PET/MR scanners are expensive and diagnostic protocols are still under studies and investigations. Nuclear Medicine imaging highlights functional and biometabolic information but has poor anatomic details. The aim of this study is to integrate MR and PET data to produce distrectual or whole body fused images acquired from different scanners even in different days. We propose an offline method to fuse PET with MR data using an open-source software that has to be inexpensive, reproducible and capable to exchange data over the network. We also evaluate global quality, alignment quality, and diagnostic confidence of fused PET-MR images. We selected PET/CT studies performed in our Nuclear Medicine unit, MR studies provided by patients on DICOM CD media or network received. We used Osirix 5.7 open source version. We aligned CT slices with the first MR slice, pointed and marked for co-registration using MR-T1 sequence and CT as reference and fused with PET to produce a PET-MR image. A total of 100 PET/CT studies were fused with the following MR studies: 20 head, 15 thorax, 24 abdomen, 31 pelvis, 10 whole body. An interval of no more than 15 days between PET and MR was the inclusion criteria. PET/CT, MR and fused studies were evaluated by two experienced radiologist and two experienced nuclear medicine physicians. Each one filled a five point based evaluation scoring scheme based on image quality, image artifacts, segmentation errors, fusion misalignment and diagnostic confidence. Our fusion method showed best results for head, thorax and pelvic districts in terms of global quality, alignment quality and diagnostic confidence,while for the abdomen and pelvis alignement quality and global quality resulted poor due to internal organs filling variation and time shifting beetwen examinations. PET/CT images with time of flight reconstruction and real attenuation correction were combined with anatomical detailed MRI images. We used Osirix, an image processing Open Source Software dedicated to DICOM images. No additional costs, to buy and upgrade proprietary software are required for combining data. No high technology or very expensive PET/MR scanner, that requires dedicated shielded room spaces and personnel to be employed or to be trained, are needed. Our method allows to share patient PET/MR fused data with different medical staff using dedicated networks. The proposed method may be applied to every MR sequence (MR-DWI and MR-STIR, magnet enhanced sequences) to characterize soft tissue alterations and improve discrimination diseases. It can be applied not only to PET with MR but virtually to every DICOM study.

A Biophysical-Computational Perspective of Breast Cancer Pathogenesis and Treatment Response

DTIC Science & Technology

2008-03-01

or for monitoring therapy responsiveness. In addition, we recently began a fruitful collaboration with Dr. Paul Hansma from UC Santa Barbara who has...Inactivation of the apoptotic effector Apaf-1 in malignant melanoma. Nature 409, 207-211 (2001). 44. Gifford, G., Paul , J., Vasey, P.A., Kaye, S.B...clustering. Data in parenthesis are 95% confidence intervals. Tissue Diagnostic Instrument Paul Hansma, Hongmei Yu, David Schultz, Azucena Rodriguez

Development and Application of a Two-Tier Diagnostic Test for High School Students' Understanding of Flowering Plant Growth and Development

ERIC Educational Resources Information Center

Lin, Sheau-Wen

2004-01-01

This study involved the development and application of a two-tier diagnostic test measuring students' understanding of flowering plant growth and development. The instrument development procedure had three general steps: defining the content boundaries of the test, collecting information on students' misconceptions, and instrument development.…

Development and Application of a Two-Tier Multiple-Choice Diagnostic Test for High School Students' Understanding of Cell Division and Reproduction

ERIC Educational Resources Information Center

Sesli, Ertugrul; Kara, Yilmaz

2012-01-01

This study involved the development and application of a two-tier diagnostic test for measuring students' understanding of cell division and reproduction. The instrument development procedure had three general steps: defining the content boundaries of the test, collecting information on students' misconceptions, and instrument development.…

Application of a Cognitive Diagnostic Model to a High-Stakes Reading Comprehension Test

ERIC Educational Resources Information Center

Ravand, Hamdollah

2016-01-01

General cognitive diagnostic models (CDM) such as the generalized deterministic input, noisy, "and" gate (G-DINA) model are flexible in that they allow for both compensatory and noncompensatory relationships among the subskills within the same test. Most of the previous CDM applications in the literature have been add-ons to simulation…

Gene expression-based molecular diagnostic system for malignant gliomas is superior to histological diagnosis.

PubMed

Shirahata, Mitsuaki; Iwao-Koizumi, Kyoko; Saito, Sakae; Ueno, Noriko; Oda, Masashi; Hashimoto, Nobuo; Takahashi, Jun A; Kato, Kikuya

2007-12-15

Current morphology-based glioma classification methods do not adequately reflect the complex biology of gliomas, thus limiting their prognostic ability. In this study, we focused on anaplastic oligodendroglioma and glioblastoma, which typically follow distinct clinical courses. Our goal was to construct a clinically useful molecular diagnostic system based on gene expression profiling. The expression of 3,456 genes in 32 patients, 12 and 20 of whom had prognostically distinct anaplastic oligodendroglioma and glioblastoma, respectively, was measured by PCR array. Next to unsupervised methods, we did supervised analysis using a weighted voting algorithm to construct a diagnostic system discriminating anaplastic oligodendroglioma from glioblastoma. The diagnostic accuracy of this system was evaluated by leave-one-out cross-validation. The clinical utility was tested on a microarray-based data set of 50 malignant gliomas from a previous study. Unsupervised analysis showed divergent global gene expression patterns between the two tumor classes. A supervised binary classification model showed 100% (95% confidence interval, 89.4-100%) diagnostic accuracy by leave-one-out cross-validation using 168 diagnostic genes. Applied to a gene expression data set from a previous study, our model correlated better with outcome than histologic diagnosis, and also displayed 96.6% (28 of 29) consistency with the molecular classification scheme used for these histologically controversial gliomas in the original article. Furthermore, we observed that histologically diagnosed glioblastoma samples that shared anaplastic oligodendroglioma molecular characteristics tended to be associated with longer survival. Our molecular diagnostic system showed reproducible clinical utility and prognostic ability superior to traditional histopathologic diagnosis for malignant glioma.

ROC curves in clinical chemistry: uses, misuses, and possible solutions.

PubMed

Obuchowski, Nancy A; Lieber, Michael L; Wians, Frank H

2004-07-01

ROC curves have become the standard for describing and comparing the accuracy of diagnostic tests. Not surprisingly, ROC curves are used often by clinical chemists. Our aims were to observe how the accuracy of clinical laboratory diagnostic tests is assessed, compared, and reported in the literature; to identify common problems with the use of ROC curves; and to offer some possible solutions. We reviewed every original work using ROC curves and published in Clinical Chemistry in 2001 or 2002. For each article we recorded phase of the research, prospective or retrospective design, sample size, presence/absence of confidence intervals (CIs), nature of the statistical analysis, and major analysis problems. Of 58 articles, 31% were phase I (exploratory), 50% were phase II (challenge), and 19% were phase III (advanced) studies. The studies increased in sample size from phase I to III and showed a progression in the use of prospective designs. Most phase I studies were powered to assess diagnostic tests with ROC areas >/=0.70. Thirty-eight percent of studies failed to include CIs for diagnostic test accuracy or the CIs were constructed inappropriately. Thirty-three percent of studies provided insufficient analysis for comparing diagnostic tests. Other problems included dichotomization of the gold standard scale and inappropriate analysis of the equivalence of two diagnostic tests. We identify available software and make some suggestions for sample size determination, testing for equivalence in diagnostic accuracy, and alternatives to a dichotomous classification of a continuous-scale gold standard. More methodologic research is needed in areas specific to clinical chemistry.

Correcting for bias in the selection and validation of informative diagnostic tests.

PubMed

Robertson, David S; Prevost, A Toby; Bowden, Jack

2015-04-15

When developing a new diagnostic test for a disease, there are often multiple candidate classifiers to choose from, and it is unclear if any will offer an improvement in performance compared with current technology. A two-stage design can be used to select a promising classifier (if one exists) in stage one for definitive validation in stage two. However, estimating the true properties of the chosen classifier is complicated by the first stage selection rules. In particular, the usual maximum likelihood estimator (MLE) that combines data from both stages will be biased high. Consequently, confidence intervals and p-values flowing from the MLE will also be incorrect. Building on the results of Pepe et al. (SIM 28:762-779), we derive the most efficient conditionally unbiased estimator and exact confidence intervals for a classifier's sensitivity in a two-stage design with arbitrary selection rules; the condition being that the trial proceeds to the validation stage. We apply our estimation strategy to data from a recent family history screening tool validation study by Walter et al. (BJGP 63:393-400) and are able to identify and successfully adjust for bias in the tool's estimated sensitivity to detect those at higher risk of breast cancer. © 2015 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.

Three-dimensional CT enterography using oral gastrografin in patients with small bowel obstruction: comparison with axial CT images or fluoroscopic findings.

PubMed

Hong, Seong Sook; Kim, Ah Young; Kwon, Seok Beom; Kim, Pyo Nyun; Lee, Moon-Gyu; Ha, Hyun Kwon

2010-10-01

To evaluate the feasibility of 3D CT enterography using oral gastrografin in patients with small bowel obstruction (SBO), focusing on improving diagnostic performance as compared with the use of axial CT imagings and fluoroscopic findings. For a 10-month period, 18 patients with known SBO detected clinically and radiologically were enrolled. In all patients, gastrografin was ingested prior to CT enterography. Twelve patients underwent a fluoroscopic examination. Images were randomly assessed for confidence for the level, for the cause of SBO, and for the assessment of the interpretability of each image by two gastrointestinal radiologists. The results were considered statistically significant using the Wilcoxon rank sum test. All patients (100%) well tolerated the administration of oral gastrografin. The use of 3D CT enterography significantly improved diagnostic confidence for the interpretation of the level, cause of SBO, and the assessment of the interpretability of each image as compared with the use of axial CT images (P < 0.05). 3D CT enterography was superior as compared to fluoroscopic examination (P < 0.05). The use of gastrografin for 3D CT enterography is a safe and feasible technique for precise evaluation of known or suspected SBO.

Comparison of two commercial rapid in-clinic serological tests for detection of antibodies against Leishmania spp. in dogs.

PubMed

Athanasiou, Labrini V; Petanides, Theodoros A; Chatzis, Manolis K; Kasabalis, Dimitrios; Apostolidis, Kosmas N; Saridomichelakis, Manolis N

2014-03-01

Antibodies against Leishmania spp. are detected in most dogs with clinical signs of leishmaniasis due to Leishmania infantum. Accurate, rapid in-clinic serological tests may permit immediate confirmation of the diagnosis and implementation of therapeutic measures. The aim of the current study was to evaluate the diagnostic accuracy of 2 commercial, rapid in-clinic serological tests for the detection of anti-Leishmania antibodies in sera of dogs, the Snap Canine Leishmania Antibody Test kit (IDEXX Laboratories Inc., Westbrook, Maine) and the ImmunoRun Antibody Detection kit (Biogal Galed Labs, Kibbutz Galed, Israel), using indirect fluorescent antibody test (IFAT) as the reference method. A total of 109 sera collected from 65 seropositive and 44 seronegative dogs were used. The sensitivities of the Snap and ImmunoRun kits were 89.23% (95% confidence interval: 79.05-95.54%) and 86.15% (95% confidence interval: 75.33-93.45%), respectively, and the specificity of both tests was 100%. A good agreement between each of the rapid in-clinic serological tests and IFAT and between the 2 rapid in-clinic serological tests was witnessed. Both rapid in-clinic serological tests showed an adequate diagnostic accuracy and can be used for the fast detection of antibodies against L. infantum in dogs.

[Companion diagnostics "POTELIGEO TEST IHC/FCM" used with "POTELIGEO" (mogamulizumab) for adult T-cell leukemia-lymphoma (ATL) treatment].

PubMed

Goami, Takeshi

2014-05-01

Personalized medicine offers the best treatment for individual patients, it is important for an IVD manufacturer to develop companion diagnostics in parallel with the development of new drugs through close cooperation with drug companies, and supply diagnostics companies with new drugs for physicians and patients. We received approval for a premarket approval application (PMA) for two in vitro diagnostic ("IVD") reagents, POTELIGEO TEST IHC and POTELIGEO TEST FCM ("POTELIGEO TEST"), in March 2012, and subsequently launched POTELIGEO TEST in May 2012. POTELIGEO TEST is a companion diagnostic used with POTELIGEO for which Kyowa Hakko Kirin has a new drug application (NDA) that was approved in March 2012, and is designed to help physicians identify appropriate subpopulations of adult T-cell leukemia-lymphoma(ATL) patients who are most likely to respond to POTELIGEO 20 mg (mogamulizumab) Injection ("POTELIGEO").

Measurements and Diagnostics of Diamond Films and Coatings

NASA Technical Reports Server (NTRS)

Miyoshi, Kazuhisa; Wu, Richard L. C.

1999-01-01

The commercial potential of chemical-vapor-deposited (CVD) diamond films has been established and a number of applications have been identified through university, industry, and government research studies. This paper discusses the methodologies used for property measurement and diagnostic of CVD diamond films and coatings. Measurement and diagnostic techniques studied include scanning electron microscopy, transmission electron microscopy, atomic force microscopy, stylus profilometry, x-ray diffraction, electron diffraction, Raman spectroscopy, Rutherford backscattering, elastic recoil spectroscopy, and friction examination. Each measurement and diagnostic technique provides unique information. A combination of techniques can provide the technical information required to understand the quality and properties of CVD diamond films, which are important to their application in specific component systems and environments. In this study the combination of measurement and diagnostic techniques was successfully applied to correlate deposition parameters and resultant diamond film composition, crystallinity, grain size, surface roughness, and coefficient of friction.

Application of Modified Spin-Echo–based Sequences for Hepatic MR Elastography: Evaluation, Comparison with the Conventional Gradient-Echo Sequence, and Preliminary Clinical Experience

PubMed Central

Mariappan, Yogesh K.; Dzyubak, Bogdan; Glaser, Kevin J.; Venkatesh, Sudhakar K.; Sirlin, Claude B.; Hooker, Jonathan; McGee, Kiaran P.

2017-01-01

Purpose To (a) evaluate modified spin-echo (SE) magnetic resonance (MR) elastographic sequences for acquiring MR images with improved signal-to-noise ratio (SNR) in patients in whom the standard gradient-echo (GRE) MR elastographic sequence yields low hepatic signal intensity and (b) compare the stiffness values obtained with these sequences with those obtained with the conventional GRE sequence. Materials and Methods This HIPAA-compliant retrospective study was approved by the institutional review board; the requirement to obtain informed consent was waived. Data obtained with modified SE and SE echo-planar imaging (EPI) MR elastographic pulse sequences with short echo times were compared with those obtained with the conventional GRE MR elastographic sequence in two patient cohorts, one that exhibited adequate liver signal intensity and one that exhibited low liver signal intensity. Shear stiffness values obtained with the three sequences in 130 patients with successful GRE-based examinations were retrospectively tested for statistical equivalence by using a 5% margin. In 47 patients in whom GRE examinations were considered to have failed because of low SNR, the SNR and confidence level with the SE-based sequences were compared with those with the GRE sequence. Results The results of this study helped confirm the equivalence of SE MR elastography and SE-EPI MR elastography to GRE MR elastography (P = .0212 and P = .0001, respectively). The SE and SE-EPI MR elastographic sequences provided substantially improved SNR and stiffness inversion confidence level in 47 patients in whom GRE MR elastography had failed. Conclusion Modified SE-based MR elastographic sequences provide higher SNR MR elastographic data and reliable stiffness measurements; thus, they enable quantification of stiffness in patients in whom the conventional GRE MR elastographic sequence failed owing to low signal intensity. The equivalence of the three sequences indicates that the current diagnostic thresholds are applicable to SE MR elastographic sequences for assessing liver fibrosis. © RSNA, 2016 PMID:27509543

Are mobile health applications useful for supporting shared decision making in diagnostic and treatment decisions?

PubMed Central

Abbasgholizadeh Rahimi, Samira; Menear, Matthew; Robitaille, Hubert; Légaré, France

2017-01-01

ABSTRACT Mobile health (mHealth) applications intended to support shared decision making in diagnostic and treatment decisions are increasingly available. In this paper, we discuss some recent studies on mHealth applications with relevance to shared decision making. We discuss the potential advantages and disadvantages of using mHealth in shared decision making in various contexts, and suggest some directions for future research in this quickly expanding field. PMID:28838306

Biomarker Development for Intraductal Papillary Mucinous Neoplasms Using Multiple Reaction Monitoring Mass Spectrometry.

PubMed

Kim, Yikwon; Kang, MeeJoo; Han, Dohyun; Kim, Hyunsoo; Lee, KyoungBun; Kim, Sun-Whe; Kim, Yongkang; Park, Taesung; Jang, Jin-Young; Kim, Youngsoo

2016-01-04

Intraductal papillary mucinous neoplasm (IPMN) is a common precursor of pancreatic cancer (PC). Much clinical attention has been directed toward IPMNs due to the increase in the prevalence of PC. The diagnosis of IPMN depends primarily on a radiological examination, but the diagnostic accuracy of this tool is not satisfactory, necessitating the development of accurate diagnostic biomarkers for IPMN to prevent PC. Recently, high-throughput targeted proteomic quantification methods have accelerated the discovery of biomarkers, rendering them powerful platforms for the evolution of IPMN diagnostic biomarkers. In this study, a robust multiple reaction monitoring (MRM) pipeline was applied to discovery and verify IPMN biomarker candidates in a large cohort of plasma samples. Through highly reproducible MRM assays and a stringent statistical analysis, 11 proteins were selected as IPMN marker candidates with high confidence in 184 plasma samples, comprising a training (n = 84) and test set (n = 100). To improve the discriminatory power, we constructed a six-protein panel by combining marker candidates. The multimarker panel had high discriminatory power in distinguishing between IPMN and controls, including other benign diseases. Consequently, the diagnostic accuracy of IPMN can be improved dramatically with this novel plasma-based panel in combination with a radiological examination.

University students' perspectives on diagnostic testing in mathematics

NASA Astrophysics Data System (ADS)

fhloinn, Eabhnat Ní; Macan Bhaird, Ciarán; Nolan, Brien

2014-01-01

Many universities issue mathematical diagnostic tests to incoming first-year students, covering a range of the basic concepts with which they should be comfortable from secondary school. As far as many lecturers are concerned, the purpose of this test is to determine the students' mathematical knowledge on entry. It should also provide an early indication of which students are likely to need additional help, and hopefully encourage such students to avail of extra support mechanisms at an early stage. However, it is not clear that students recognize these intentions and there is a fear that students who score poorly in the test will have their confidence further damaged in relation to mathematics and will be reluctant to seek help. To this end, a questionnaire was developed to explore students' perspectives on diagnostic testing. Analysis of responses received to the questionnaire provided an interesting insight into students' perspectives including the optimum time to conduct such a test, their views on the aims of diagnostic testing, whether they feel that testing is a good idea, and their attitudes to the support systems put in place to help those who scored poorly in the test.

Identification misconception of primary school teacher education students in changes of matters using a five-tier diagnostic test

NASA Astrophysics Data System (ADS)

Bayuni, T. C.; Sopandi, W.; Sujana, A.

2018-05-01

This research was conducted on third grade students (III) semester six, with sample number 84 respondents. The method used in this research is descriptive method. This article identifies the misconceptions of Primary School Teacher Education students by using a five tier diagnostic test research instrument, a question adapted to three chemical representations accompanied by an open reason and a level of confidence in the choice of answers. The categorization of the five tier diagnostic test scoring is divided into four namely, understand the concept, lack of concept, misconception and not understand the concept. Questionnaire in the form of a closed questionnaire is used to determine the factors that cause misconception. The data obtained is misconception has the highest percentage on the concept of substance properties and changes in its form. The highest incidence of misconceptions is due to self-factors. The conclusion is that five tier diagnostic tests can be used to uncover misconceptions of elementary school teachers and assist teachers in presenting lesson material tailored to the chemical representation so that students can understand the concept of the nature of matter and change its form well.

Cosmological model-independent test of ΛCDM with two-point diagnostic by the observational Hubble parameter data

NASA Astrophysics Data System (ADS)

Cao, Shu-Lei; Duan, Xiao-Wei; Meng, Xiao-Lei; Zhang, Tong-Jie

2018-04-01

Aiming at exploring the nature of dark energy (DE), we use forty-three observational Hubble parameter data (OHD) in the redshift range 0 < z ≤slant 2.36 to make a cosmological model-independent test of the ΛCDM model with two-point Omh^2(z2;z1) diagnostic. In ΛCDM model, with equation of state (EoS) w=-1, two-point diagnostic relation Omh^2 ≡ Ωmh^2 is tenable, where Ωm is the present matter density parameter, and h is the Hubble parameter divided by 100 {km s^{-1 Mpc^{-1}}}. We utilize two methods: the weighted mean and median statistics to bin the OHD to increase the signal-to-noise ratio of the measurements. The binning methods turn out to be promising and considered to be robust. By applying the two-point diagnostic to the binned data, we find that although the best-fit values of Omh^2 fluctuate as the continuous redshift intervals change, on average, they are continuous with being constant within 1 σ confidence interval. Therefore, we conclude that the ΛCDM model cannot be ruled out.

Diagnosing delirium in critically ill children: Validity and reliability of the Pediatric Confusion Assessment Method for the Intensive Care Unit*

PubMed Central

Smith, Heidi A. B.; Boyd, Jenny; Fuchs, D. Catherine; Melvin, Kelly; Berry, Pamela; Shintani, Ayumi; Eden, Svetlana K.; Terrell, Michelle K.; Boswell, Tonya; Wolfram, Karen; Sopfe, Jenna; Barr, Frederick E.; Pandharipande, Pratik P.; Ely, E. Wesley

2013-01-01

Objective To validate a diagnostic instrument for pediatric delirium in critically ill children, both ventilated and nonventilated, that uses standardized, developmentally appropriate measurements. Design and Setting A prospective observational cohort study investigating the Pediatric Confusion Assessment Method for Intensive Care Unit (pCAM-ICU) patients in the pediatric medical, surgical, and cardiac intensive care unit of a university-based medical center. Patients A total of 68 pediatric critically ill patients, at least 5 years of age, were enrolled from July 1, 2008, to March 30, 2009. Interventions None. Measurements Criterion validity including sensitivity and specificity and interrater reliability were determined using daily delirium assessments with the pCAM-ICU by two critical care clinicians compared with delirium diagnosis by pediatric psychiatrists using Diagnostic and Statistical Manual, 4th Edition, Text Revision criteria. Results A total of 146 paired assessments were completed among 68 enrolled patients with a mean age of 12.2 yrs. Compared with the reference standard for diagnosing delirium, the pCAM-ICU demonstrated a sensitivity of 83% (95% confidence interval, 66–93%), a specificity of 99% (95% confidence interval, 95–100%), and a high interrater reliability (κ = 0.96; 95% confidence interval, 0.74–1.0). Conclusions The pCAM-ICU is a highly valid reliable instrument for the diagnosis of pediatric delirium in critically ill children chronologically and developmentally at least 5 yrs of age. Use of the pCAM-ICU may expedite diagnosis and consultation with neuropsychiatry specialists for treatment of pediatric delirium. In addition, the pCAM-ICU may provide a means for delirium monitoring in future epidemiologic and interventional studies in critically ill children. (Crit Care Med 2011; 39:150–157) PMID:20959783

Diagnosing delirium in critically ill children: Validity and reliability of the Pediatric Confusion Assessment Method for the Intensive Care Unit.

PubMed

Smith, Heidi A B; Boyd, Jenny; Fuchs, D Catherine; Melvin, Kelly; Berry, Pamela; Shintani, Ayumi; Eden, Svetlana K; Terrell, Michelle K; Boswell, Tonya; Wolfram, Karen; Sopfe, Jenna; Barr, Frederick E; Pandharipande, Pratik P; Ely, E Wesley

2011-01-01

To validate a diagnostic instrument for pediatric delirium in critically ill children, both ventilated and nonventilated, that uses standardized, developmentally appropriate measurements. A prospective observational cohort study investigating the Pediatric Confusion Assessment Method for Intensive Care Unit (pCAM-ICU) patients in the pediatric medical, surgical, and cardiac intensive care unit of a university-based medical center. A total of 68 pediatric critically ill patients, at least 5 years of age, were enrolled from July 1, 2008, to March 30, 2009. None. Criterion validity including sensitivity and specificity and interrater reliability were determined using daily delirium assessments with the pCAM-ICU by two critical care clinicians compared with delirium diagnosis by pediatric psychiatrists using Diagnostic and Statistical Manual, 4th Edition, Text Revision criteria. A total of 146 paired assessments were completed among 68 enrolled patients with a mean age of 12.2 yrs. Compared with the reference standard for diagnosing delirium, the pCAM-ICU demonstrated a sensitivity of 83% (95% confidence interval, 66-93%), a specificity of 99% (95% confidence interval, 95-100%), and a high interrater reliability (κ = 0.96; 95% confidence interval, 0.74-1.0). The pCAM-ICU is a highly valid reliable instrument for the diagnosis of pediatric delirium in critically ill children chronologically and developmentally at least 5 yrs of age. Use of the pCAM-ICU may expedite diagnosis and consultation with neuropsychiatry specialists for treatment of pediatric delirium. In addition, the pCAM-ICU may provide a means for delirium monitoring in future epidemiologic and interventional studies in critically ill children.

Assessment of representational competence in kinematics

NASA Astrophysics Data System (ADS)

Klein, P.; Müller, A.; Kuhn, J.

2017-06-01

A two-tier instrument for representational competence in the field of kinematics (KiRC) is presented, designed for a standard (1st year) calculus-based introductory mechanics course. It comprises 11 multiple choice (MC) and 7 multiple true-false (MTF) questions involving multiple representational formats, such as graphs, pictures, and formal (mathematical) expressions (1st tier). Furthermore, students express their answer confidence for selected items, providing additional information (2nd tier). Measurement characteristics of KiRC were assessed in a validation sample (pre- and post-test, N =83 and N =46 , respectively), including usefulness for measuring learning gain. Validity is checked by interviews and by benchmarking KiRC against related measures. Values for item difficulty, discrimination, and consistency are in the desired ranges; in particular, a good reliability was obtained (KR 20 =0.86 ). Confidence intervals were computed and a replication study yielded values within the latter. For practical and research purposes, KiRC as a diagnostic tool goes beyond related extant instruments both for the representational formats (e.g., mathematical expressions) and for the scope of content covered (e.g., choice of coordinate systems). Together with the satisfactory psychometric properties it appears a versatile and reliable tool for assessing students' representational competency in kinematics (and of its potential change). Confidence judgments add further information to the diagnostic potential of the test, in particular for representational misconceptions. Moreover, we present an analytic result for the question—arising from guessing correction or educational considerations—of how the total effect size (Cohen's d ) varies upon combination of two test components with known individual effect sizes, and then discuss the results in the case of KiRC (MC and MTF combination). The introduced method of test combination analysis can be applied to any test comprising two components for the purpose of finding effect size ranges.

Development of a real time monitor and multivariate method for long term diagnostics of atmospheric pressure dielectric barrier discharges: application to He, He/N2, and He/O2 discharges.

PubMed

O'Connor, N; Milosavljević, V; Daniels, S

2011-08-01

In this paper we present the development and application of a real time atmospheric pressure discharge monitoring diagnostic. The software based diagnostic is designed to extract latent electrical and optical information associated with the operation of an atmospheric pressure dielectric barrier discharge (APDBD) over long time scales. Given that little is known about long term temporal effects in such discharges, the diagnostic methodology is applied to the monitoring of an APDBD in helium and helium with both 0.1% nitrogen and 0.1% oxygen gas admixtures over periods of tens of minutes. Given the large datasets associated with the experiments, it is shown that this process is much expedited through the novel application of multivariate correlations between the electrical and optical parameters of the corresponding chemistries which, in turn, facilitates comparisons between each individual chemistry also. The results of these studies show that the electrical and optical parameters of the discharge in helium and upon the addition of gas admixtures evolve over time scales far longer than the gas residence time and have been compared to current modelling works. It is envisaged that the diagnostic together with the application of multivariate correlations will be applied to rapid system identification and prototyping in both experimental and industrial APDBD systems in the future.

[Risk on bias assessment: (6) A Revised Tool for the Quality Assessment on Diagnostic Accuracy Studies (QUADAS-2)].

PubMed

Qu, Y J; Yang, Z R; Sun, F; Zhan, S Y

2018-04-10

This paper introduced the Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2), including the development and comparison with the original QUADAS, and illustrated the application of QUADAS-2 in a published paper related to the study on diagnostic accuracy which was included in systematic review and Meta-analysis. QUADAS-2 presented considerable improvement over the original tool. Confused items that included in QUADAS had disappeared and the quality assessment of the original study replaced by the rating of risk on bias and applicability. This was implemented through the description on the four main domains with minimal overlapping and answering the signal questions in each domain. The risk of bias and applicability with 'high','low' or 'unclear' was in line with the risk of bias assessment of intervention studies in Cochrane, so to replace the total score of quality assessment in QUADAS. Meanwhile, QUADAS-2 was also applicable to assess the diagnostic accuracy studies in which follow-up without prognosis was involved in golden standard. It was useful to assess the overall methodological quality of the study despite more time consuming than the original QUADAS. However, QUADAS-2 needs to be modified to apply in comparative studies on diagnostic accuracy and we hope the users would follow the updates and give their feedbacks on line.

Automated audiometry using apple iOS-based application technology.

PubMed

Foulad, Allen; Bui, Peggy; Djalilian, Hamid

2013-11-01

The aim of this study is to determine the feasibility of an Apple iOS-based automated hearing testing application and to compare its accuracy with conventional audiometry. Prospective diagnostic study. Setting Academic medical center. An iOS-based software application was developed to perform automated pure-tone hearing testing on the iPhone, iPod touch, and iPad. To assess for device variations and compatibility, preliminary work was performed to compare the standardized sound output (dB) of various Apple device and headset combinations. Forty-two subjects underwent automated iOS-based hearing testing in a sound booth, automated iOS-based hearing testing in a quiet room, and conventional manual audiometry. The maximum difference in sound intensity between various Apple device and headset combinations was 4 dB. On average, 96% (95% confidence interval [CI], 91%-100%) of the threshold values obtained using the automated test in a sound booth were within 10 dB of the corresponding threshold values obtained using conventional audiometry. When the automated test was performed in a quiet room, 94% (95% CI, 87%-100%) of the threshold values were within 10 dB of the threshold values obtained using conventional audiometry. Under standardized testing conditions, 90% of the subjects preferred iOS-based audiometry as opposed to conventional audiometry. Apple iOS-based devices provide a platform for automated air conduction audiometry without requiring extra equipment and yield hearing test results that approach those of conventional audiometry.

Diagnostic value of FIB-4 for liver fibrosis in patients with hepatitis B: a meta-analysis of diagnostic test.

PubMed

Yin, Zhi; Zou, Jin; Li, Qiongxuan; Chen, Lizhang

2017-04-04

This study is aimed at evaluating the diagnostic value of FIB-4 for liver fibrosis in patients with hepatitis B through a meta-analysis of diagnostic test. We conducted a comprehensive search in the Pubmed, Embase, Web of Science, and Chinese National Knowledge Infrastructure before October 31, 2016. Stata 14.0 software was used for calculation and statistical analyses. We used the sensitivity, specificity, positive and negative likelihood ratio (PLR, NLR), diagnostic odds ratio (DOR) and 95% confidence intervals (CIs) to evaluate the diagnostic value of FIB-4 for liver fibrosis in patients with hepatitis B. Twenty-six studies were included in the final analyses, with a total of 8274 individuals. The pooled parameters are calculated from all studies: sensitivity of 0.69 (95%CI:0.63-0.75), specificity of 0.81 (95%CI: 0.73-0.87), PLR of 3.63 (95%CI:2.66-4.94), NLR of 0.38 (95%CI:0.32-0.44), DOR of 9.57 (95%CI: 6.67-13.74), and area under the curve (AUC) of 0.80 (95%CI: 0.76-0.83). We also conducted subgroup based on the range of cut-off values. Results from subgroup analysis showed that cut-off was the source of heterogeneity in the present study. The sensitivity and specificity of cut-off>2 were 0.69 and 0.95 with the AUC of 0.90 (95%CI: 0.87-0.92). The overall diagnostic value of FIB-4 is not very high for liver fibrosis in patients with hepatitis B. However, the diagnostic value is affected by the cut-off value. FIB-4 has relatively high diagnostic value for detecting liver fibrosis in patients with hepatitis B when the diagnostic threshold value is more than 2.0.

Diagnostic and interventional musculoskeletal ultrasound: part 2. Clinical applications.

PubMed

Smith, Jay; Finnoff, Jonathan T

2009-02-01

Musculoskeletal ultrasound involves the use of high-frequency sound waves to image soft tissues and bony structures in the body for the purposes of diagnosing pathology or guiding real-time interventional procedures. Recently, an increasing number of physicians have integrated musculoskeletal ultrasound into their practices to facilitate patient care. Technological advancements, improved portability, and reduced costs continue to drive the proliferation of ultrasound in clinical medicine. This increased interest creates a need for education pertaining to all aspects of musculoskeletal ultrasound. The primary purpose of this article is to review diagnostic ultrasound technology and its potential clinical applications in the evaluation and treatment of patients with neurological and musculoskeletal disorders. After reviewing this article, physicians should be able to (1) list the advantages and disadvantages of ultrasound compared to other available imaging modalities; (2) describe how ultrasound machines produce images using sound waves; (3) discuss the steps necessary to acquire and optimize an ultrasound image; (4) understand the difference ultrasound appearances of tendons, nerves, muscles, ligaments, blood vessels, and bones; and (5) identify multiple applications for diagnostic and interventional musculoskeletal ultrasound. Part 2 of this 2-part article will focus on the clinical applications of musculoskeletal ultrasound in clinical practice, including the ultrasonographic appearance of normal and abnormal tissues as well as specific diagnostic and interventional applications in major body regions.

"Yes, we can!" review on team confidence in sports.

PubMed

Fransen, Katrien; Mertens, Niels; Feltz, Deborah; Boen, Filip

2017-08-01

During the last decade, team confidence has received more and more attention in the sport psychology literature. Research has demonstrated that athletes who are more confident in their team's abilities exert more effort, set more challenging goals, are more resilient when facing adversities, and ultimately perform better. This article reviews the existing literature in order to provide more clarity in terms of the conceptualization and the operationalization of team confidence. We thereby distinguish between collective efficacy (i.e., process-oriented team confidence) and team outcome confidence (i.e., outcome-oriented team confidence). In addition, both the sources as well as the outcomes of team confidence will be discussed. Furthermore, we will go deeper into the dispersion of team confidence and we will evaluate the current guidelines on how to measure both types of team confidence. Building upon this base, the article then highlights interesting avenues for future research in order to further improve both our theoretical knowledge on team confidence and its application to the field. Copyright © 2017 Elsevier Ltd. All rights reserved.

Diagnostic accuracy of laparoscopy following computed tomography (CT) scanning for assessing the resectability with curative intent in pancreatic and periampullary cancer.

PubMed

Allen, Victoria B; Gurusamy, Kurinchi Selvan; Takwoingi, Yemisi; Kalia, Amun; Davidson, Brian R

2016-07-06

Surgical resection is the only potentially curative treatment for pancreatic and periampullary cancer. A considerable proportion of patients undergo unnecessary laparotomy because of underestimation of the extent of the cancer on computed tomography (CT) scanning. Laparoscopy can detect metastases not visualised on CT scanning, enabling better assessment of the spread of cancer (staging of cancer). This is an update to a previous Cochrane Review published in 2013 evaluating the role of diagnostic laparoscopy in assessing the resectability with curative intent in people with pancreatic and periampullary cancer. To determine the diagnostic accuracy of diagnostic laparoscopy performed as an add-on test to CT scanning in the assessment of curative resectability in pancreatic and periampullary cancer. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via PubMed, EMBASE via OvidSP (from inception to 15 May 2016), and Science Citation Index Expanded (from 1980 to 15 May 2016). We included diagnostic accuracy studies of diagnostic laparoscopy in people with potentially resectable pancreatic and periampullary cancer on CT scan, where confirmation of liver or peritoneal involvement was by histopathological examination of suspicious (liver or peritoneal) lesions obtained at diagnostic laparoscopy or laparotomy. We accepted any criteria of resectability used in the studies. We included studies irrespective of language, publication status, or study design (prospective or retrospective). We excluded case-control studies. Two review authors independently performed data extraction and quality assessment using the QUADAS-2 tool. The specificity of diagnostic laparoscopy in all studies was 1 because there were no false positives since laparoscopy and the reference standard are one and the same if histological examination after diagnostic laparoscopy is positive. The sensitivities were therefore meta-analysed using a univariate random-effects logistic regression model. The probability of unresectability in people who had a negative laparoscopy (post-test probability for people with a negative test result) was calculated using the median probability of unresectability (pre-test probability) from the included studies, and the negative likelihood ratio derived from the model (specificity of 1 assumed). The difference between the pre-test and post-test probabilities gave the overall added value of diagnostic laparoscopy compared to the standard practice of CT scan staging alone. We included 16 studies with a total of 1146 participants in the meta-analysis. Only one study including 52 participants had a low risk of bias and low applicability concern in the patient selection domain. The median pre-test probability of unresectable disease after CT scanning across studies was 41.4% (that is 41 out of 100 participants who had resectable cancer after CT scan were found to have unresectable disease on laparotomy). The summary sensitivity of diagnostic laparoscopy was 64.4% (95% confidence interval (CI) 50.1% to 76.6%). Assuming a pre-test probability of 41.4%, the post-test probability of unresectable disease for participants with a negative test result was 0.20 (95% CI 0.15 to 0.27). This indicates that if a person is said to have resectable disease after diagnostic laparoscopy and CT scan, there is a 20% probability that their cancer will be unresectable compared to a 41% probability for those receiving CT alone.A subgroup analysis of people with pancreatic cancer gave a summary sensitivity of 67.9% (95% CI 41.1% to 86.5%). The post-test probability of unresectable disease after being considered resectable on both CT and diagnostic laparoscopy was 18% compared to 40.0% for those receiving CT alone. Diagnostic laparoscopy may decrease the rate of unnecessary laparotomy in people with pancreatic and periampullary cancer found to have resectable disease on CT scan. On average, using diagnostic laparoscopy with biopsy and histopathological confirmation of suspicious lesions prior to laparotomy would avoid 21 unnecessary laparotomies in 100 people in whom resection of cancer with curative intent is planned.

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

Kilkenny, J.; Richau, G.; Sangster, C.

A major goal of the Stockpile Stewardship Program (SSP) is to deliver validated numerical models, benchmarked against experiments that address relevant and important issues and provide data that stress the codes and our understanding. DOENNSA has made significant investments in major facilities and high-performance computing to successfully execute the SSP. The more information obtained about the physical state of the plasmas produced, the more stringent the test of theories, models, and codes can be, leading to increased confidence in our predictive capability. To fully exploit the world-leading capabilities of the ICF program, a multi-year program to develop and deploy advancedmore » diagnostics has been developed by the expert scientific community. To formalize these activities NNSA’s Acting Director for the Inertial Confinement Fusion Program directed the formation and duties of the National Diagnostics Working Group (NDWG) in a Memorandum 11/3/16 (Appendix A). The NDWG identified eight transformational diagnostics, shown in Table 1, that will provide unprecedented information from experiments in support of the SSP at NIF, Z and OMEGA. Table 1 shows how the missions of the SSP experiments including materials, complex hydrodynamics, radiation flow and effects and thermo-nuclear burn and boost will produce new observables, which will be measured using a variety of largely new diagnostic technologies used in the eight transformational diagnostics. The data provided by these diagnostics will validate and improve the physics contained within the SSP’s simulations and both uncover and quantify important phenomena that lie beyond our present understanding.« less

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

Diagnostic value of KLK6 as an ovarian cancer biomarker: A meta-analysis.

PubMed

Yang, Fan; Hu, Zhi-DE; Chen, Yingjian; Hu, Cheng-Jin

2016-06-01

Kallikrein-related peptidase 6 (KLK6) is a new potential serum biomarker of ovarian cancer. The aim of the present study was to assess the diagnostic value of KLK6 systematically for ovarian cancer. All the selected studies regarding the changes of KLK6 in ovarian cancer were published prior to April 2015. Five studies involving 485 patients with ovarian cancer, 420 benign cysts and 245 healthy controls met the inclusion criteria. The value of sensitivity, specificity, positive-likelihood ratio (LR+), negative-likelihood ratio (LR-) and area under the receiver operating characteristic curve (ROC) were obtained. All these indices were used to evaluate the diagnostic value of KLK6 for ovarian cancer. The values of sensitivity, specificity, LR+ and LR- (95% confidence interval) of KLK6 were 0.50 (0.47-0.54), 0.91 (0.89-0.93), 7.20 (3.34-15.52) and 0.51 (0.43-0.62), respectively. The area under the summary ROC of KLK6 was 0.86. The index of Q* was 0.79. In conclusion, KLK6 showed high specificity for the diagnosis of ovarian cancer. It can improve the diagnostic accuracy of cancer antigen 125 (CA125). A combined panel of CA125 and KL K6 shows a high diagnostic efficiency for advanced ovarian cancer. Owing to the small number of studies and lack of samples, additional studies meeting the inclusion criteria are required to further analyze the diagnostic value of KLK6 for ovarian cancer.

20 CFR 404.1579 - How we will determine whether your disability continues or ends.

Code of Federal Regulations, 2012 CFR

2012-04-01

... application. (2) Substantial evidence shows that based on new or improved diagnostic or evaluative techniques... favorable decision. Changing methodologies and advances in medical and other diagnostic or evaluative... subpart will be based on new or improved diagnostic or evaluative techniques. Such listing changes will...

20 CFR 404.1579 - How we will determine whether your disability continues or ends.

Code of Federal Regulations, 2014 CFR

2014-04-01

... application. (2) Substantial evidence shows that based on new or improved diagnostic or evaluative techniques... favorable decision. Changing methodologies and advances in medical and other diagnostic or evaluative... subpart will be based on new or improved diagnostic or evaluative techniques. Such listing changes will...

20 CFR 404.1579 - How we will determine whether your disability continues or ends.

Code of Federal Regulations, 2010 CFR

2010-04-01

... application. (2) Substantial evidence shows that based on new or improved diagnostic or evaluative techniques... favorable decision. Changing methodologies and advances in medical and other diagnostic or evaluative... subpart will be based on new or improved diagnostic or evaluative techniques. Such listing changes will...

20 CFR 404.1579 - How we will determine whether your disability continues or ends.

Code of Federal Regulations, 2011 CFR

2011-04-01

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20 CFR 404.1579 - How we will determine whether your disability continues or ends.

Code of Federal Regulations, 2013 CFR

2013-04-01

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77 FR 4368 - Abbott Laboratories, Diagnostics Division, Including On-Site Leased Workers From Manpower...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-27

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-75,201] Abbott Laboratories..., applicable to workers of Abbott Laboratories, Diagnostics Division, including on-site leased workers from... (clerical) were employed on-site at the Irving, Texas location of Abbott Laboratories, Diagnostics Division...

77 FR 2071 - Medical Devices; Availability of Safety and Effectiveness Summaries for Premarket Approval...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-13

.... Docket No. Applicant Trade name Approval date P100031, FDA-2011-M-0502...... Roche Diagnostics ELECSYS......... Roche Diagnostics ELECSYS ANTI-HBC IMMUNOASSAY, June 27, 2011. Corp.. ELECSYS PRECICONTROL ANTI-HBC FOR... IMMUNODIAGNOSTICS July 20, 2011. Diagnostics, PRODUCTS ANTI-HBE REAGENT PACK, Inc.. VITROS IMMUNODIAGNOSTIC PRODUCTS...

Modeling Diagnostic Assessments with Bayesian Networks

ERIC Educational Resources Information Center

Almond, Russell G.; DiBello, Louis V.; Moulder, Brad; Zapata-Rivera, Juan-Diego

2007-01-01

This paper defines Bayesian network models and examines their applications to IRT-based cognitive diagnostic modeling. These models are especially suited to building inference engines designed to be synchronous with the finer grained student models that arise in skills diagnostic assessment. Aspects of the theory and use of Bayesian network models…

Multi-Tasking Non-Destructive Laser Technology in Conservation Diagnostic Procedures

NASA Astrophysics Data System (ADS)

Tornari, V.; Tsiranidou, E.; Orphanos, Y.; Falldorf, C.; Klattenhof, R.; Esposito, E.; Agnani, A.; Dabu, R.; Stratan, A.; Anastassopoulos, A.; Schipper, D.; Hasperhoven, J.; Stefanaggi, M.; Bonnici, H.; Ursu, D.

Laser metrology provides techniques that have been successfully applied in industrial structural diagnostic fields but have not yet been refined and optimised for the special investigative requirements found in cultural heritage applications. A major impediment is the partial applicability of various optical coherent techniques, each one narrowing its use down to a specific application. This characteristic is not well suited for a field that encounters a great variety of diagnostic problems ranging from movable, multiple-composition museum objects, to immovable multi-layered wall paintings, statues and wood carvings, to monumental constructions and outdoor cultural heritage sites. Various diagnostic techniques have been suggested and are uniquely suited for each of the mentioned problems but it is this fragmented suitability that obstructs the technology transfer. Since optical coherent techniques for metrology are based on fundamental principles and take advantage of similar procedures for generation of informative signals for data collection, then the imposed limits elevate our aim to identify complementary capabilities to accomplish the needed functionality.

Easy and Informative: Using Confidence-Weighted True-False Items for Knowledge Tests in Psychology Courses

ERIC Educational Resources Information Center

Dutke, Stephan; Barenberg, Jonathan

2015-01-01

We introduce a specific type of item for knowledge tests, confidence-weighted true-false (CTF) items, and review experiences of its application in psychology courses. A CTF item is a statement about the learning content to which students respond whether the statement is true or false, and they rate their confidence level. Previous studies using…

Microbial Diagnostic Array Workstation (MDAW): a web server for diagnostic array data storage, sharing and analysis

PubMed Central

Scaria, Joy; Sreedharan, Aswathy; Chang, Yung-Fu

2008-01-01

Background Microarrays are becoming a very popular tool for microbial detection and diagnostics. Although these diagnostic arrays are much simpler when compared to the traditional transcriptome arrays, due to the high throughput nature of the arrays, the data analysis requirements still form a bottle neck for the widespread use of these diagnostic arrays. Hence we developed a new online data sharing and analysis environment customised for diagnostic arrays. Methods Microbial Diagnostic Array Workstation (MDAW) is a database driven application designed in MS Access and front end designed in ASP.NET. Conclusion MDAW is a new resource that is customised for the data analysis requirements for microbial diagnostic arrays. PMID:18811969

Microbial Diagnostic Array Workstation (MDAW): a web server for diagnostic array data storage, sharing and analysis.

PubMed

Scaria, Joy; Sreedharan, Aswathy; Chang, Yung-Fu

2008-09-23

Microarrays are becoming a very popular tool for microbial detection and diagnostics. Although these diagnostic arrays are much simpler when compared to the traditional transcriptome arrays, due to the high throughput nature of the arrays, the data analysis requirements still form a bottle neck for the widespread use of these diagnostic arrays. Hence we developed a new online data sharing and analysis environment customised for diagnostic arrays. Microbial Diagnostic Array Workstation (MDAW) is a database driven application designed in MS Access and front end designed in ASP.NET. MDAW is a new resource that is customised for the data analysis requirements for microbial diagnostic arrays.

Improving "lab-on-a-chip" techniques using biomedical nanotechnology: a review.

PubMed

Gorjikhah, Fatemeh; Davaran, Soodabeh; Salehi, Roya; Bakhtiari, Mohsen; Hasanzadeh, Arash; Panahi, Yunes; Emamverdy, Masumeh; Akbarzadeh, Abolfazl

2016-11-01

Nanotechnology and its applications in biomedical sciences principally in molecular nanodiagnostics are known as nanomolecular diagnostics, which provides new options for clinical nanodiagnostic techniques. Molecular nanodiagnostics are a critical role in the development of personalized medicine, which features point-of care performance of diagnostic procedure. This can to check patients at point-of-care facilities or in remote or resource-poor locations, therefore reducing checking time from days to minutes. In this review, applications of nanotechnology suited to biomedicine are discussed in two main class: biomedical applications for use inside (such as drugs, diagnostic techniques, prostheses, and implants) and outside the body (such as "lab-on-a-chip" techniques). A lab-on-a-chip (LOC) is a tool that incorporates numerous laboratory tasks onto a small device, usually only millimeters or centimeters in size. Finally, are discussed the applications of biomedical nanotechnology in improving "lab-on-a-chip" techniques.

Semiconductor lasers vs LEDs in diagnostic and therapeutic medicine

NASA Astrophysics Data System (ADS)

Gryko, Lukasz; Zajac, Andrzej; Szymanska, Justyna; Blaszczak, Urszula; Palkowska, Anna; Kulesza, Ewa

2016-12-01

Semiconductor emitters are used in many areas of medicine, allowing for new methods of diagnosis, treatment and effective prevention of many diseases. The article presents selected areas of application of semiconductor sources in UVVIS- NIR range, where in recent years competition in semiconductor lasers and LEDs applications has been observed. Examples of applications of analyzed sources are indicated for LLLT, PDT and optical diagnostics using the procedure of color contrast. Selected results of LLLT research of the authors are presented that were obtained by means of the developed optoelectronic system for objectified irradiation and studies on the impact of low-energy laser and LED on lines of endothelial cells of umbilical vein. Usefulness of the spectrally tunable LED lighting system for diagnostic purposes is also demonstrated, also as an illuminator for surface applications - in procedure of variable color contrast of the illuminated object.

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.

Clinical implications of plasma Nogo-A levels in patients with coronary heart disease.

PubMed

Ding, Yu; Gao, Bei-Bei; Zhou, Liang; Ye, Xian-Hua; Li, Hong; Lai, Lei; Huang, Jin-Yu

2017-06-01

Nogo-A is an important neurite growth-regulatory protein in the adult and developing nervous system. Recently, increasing evidence has shown that Nogo-A plays important roles in cardiac development and may act as a potential indicator for heart failure. In addition, increased oxidative stress has been found in individuals with cardiovascular diseases. However, not much is known regarding the expression levels of Nogo-A and reactive oxygen species (ROS) in patients with coronary heart disease (CHD). Therefore, we sought to investigate the relationship between Nogo-A, ROS levels and CHD. The plasma Nogo-A and ROS concentrations of 122 acute coronary syndrome (ACS), 101 unstable angina pectoris (UAP), and 21 acute myocardial infarction (AMI) patients and 56 healthy controls were measured by enzyme-linked immunosorbent assay (ELISA). We further generated a receiver operating characteristic (ROC) curve to assess the diagnostic accuracy of Nogo-A and ROS in CHD. The Nogo-A and ROS levels were significantly higher in patients with CHD than those in healthy controls. In addition, multivariate logistic regression analysis revealed that the level of Nogo-A (odds ratio (OR) = 1.624, 95% confidence interval: 1.125-2.293, p = 0.009) is a risk factor for prediction of CHD. Nogo-A has diagnostic value, with an optimal threshold of 5.466 ng/ml for maximized diagnostic performance (59% sensitivity and 78.6% specificity, area under curve, p < 0.05). However, ROS concentration is not a risk factor for prediction of CHD (OR = 0.999, 95% confidence interval: 0.997-1.001, p = 0.320). Increased plasma Nogo-A level may be associated with CHD.

CT angiography for one-year follow-up of intracranial aneurysms treated with the WEB device: Utility in evaluating aneurysm occlusion and WEB compression at one year.

PubMed

Raoult, Hélène; Eugène, François; Le Bras, Anthony; Mineur, Géraldine; Carsin-Nicol, Béatrice; Ferré, Jean-Christophe; Gauvrit, Jean-Yves

2018-03-07

The WEB is an innovative flow disruption device for cerebral aneurysm embolization with rapidly expanding indications. Our purpose was to evaluate the diagnostic performance of computed tomography angiography (CTA) at 1-year follow-up of aneurysms treated with the WEB. Between April 2014 and May 2016, the study prospectively included patients treated with the WEB at our institution, and followed up within 24hours by CTA and at 1year by CTA, time-of-flight magnetic resonance angiography (TOF MRA) and digital subtraction angiography (DSA). The diagnostic quality of imaging data was assessed based on the confidence index, artifacts, and WEB shape depiction. The imaging diagnostic performance was assessed using 3 criteria at 1year: aneurysm occlusion status and worsening, and WEB shape compression. Interobserver and intermodality agreement was determined by calculating κ values. The study ultimately included 16 patients (9 women, mean age 53±7.6years). CTA quality confidence was scored as 2/2, artifacts 0.4/2 and WEB shape depiction 1.9/2, superior to TOF MRA for the latter two criteria. Aneurysm occlusion was adequate in 93.7% of patients, with CTA showing excellent interobserver reproducibility and agreement with DSA on a 4-grade scale (κ=1.00), while TOF MRA yielded good reproducibility (κ=0.76) and agreement with DSA (κ=0.69). CTA also identified aneurysm occlusion worsening (43.7%) and WEB compression (81.2%) in excellent agreement with DSA (κ=0.85 and 1.00). CTA is a reproducible and reliable technique for the follow-up of aneurysms treated with the WEB device. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Sentinel Lymphadenectomy in Vulvar Cancer Using Near-Infrared Fluorescence From Indocyanine Green Compared With Technetium 99m Nanocolloid.

PubMed

Soergel, Philipp; Hertel, Hermann; Nacke, Anna Kaarina; Klapdor, Rüdiger; Derlin, Thorsten; Hillemanns, Peter

2017-05-01

Nowadays, sentinel diagnostic is performed using technetium 99m (Tc) nanocolloid as a radioactive marker and sometimes patent blue. In the last years, indocyanine green has been evaluated for sentinel diagnostic in different tumor entities. Indocyanine green is a fluorescent molecule that emits a light signal in the near-infrared band after excitation. Our study aimed to evaluate indocyanine green compared with the criterion-standard Tc-nanocolloid. We included patients with primary, unifocal vulvar cancer of less than 4 cm with clinically node-negative groins in this prospective trial. Sentinel diagnostic was carried out using Tc-nanocolloid, indocyanine green, and patent blue. We examined each groin for light signals from the near-infrared band, for radioactivity, and for blue staining. A sentinel lymph node was defined as a Tc-nanocolloid-positive lymph node. All sentinel lymph nodes and all additional blue or fluorescent lymph nodes were excised and tested and then sent for histologic examination. In all, 27 patients were included in whom we found 91 sentinel lymph nodes in 52 groins. All these lymph nodes were positive for indocyanine green, also giving a sensitivity of 100% (95% confidence interval [CI], 96.0%-100%) compared with Tc-nanocolloid. Eight additional lymph nodes showed indocyanine green fluorescence but no Tc positivity, so that the positive predictive value was 91.9% (95% confidence interval, 84.6%-96.5%). In 1 patient, a false-negative sentinel missed by all 3 modalities was found. Our results show that indocyanine green is a promising approach for inguinal sentinel identification in vulvar cancer with a similar sensitivity as radioactive Tc-nanocolloid and worth to be evaluated in further studies.

Evaluation of the Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis (MPATH-Dx) classification scheme for diagnosis of cutaneous melanocytic neoplasms: Results from the International Melanoma Pathology Study Group.

PubMed

Lott, Jason P; Elmore, Joann G; Zhao, Ge A; Knezevich, Stevan R; Frederick, Paul D; Reisch, Lisa M; Chu, Emily Y; Cook, Martin G; Duncan, Lyn M; Elenitsas, Rosalie; Gerami, Pedram; Landman, Gilles; Lowe, Lori; Messina, Jane L; Mihm, Martin C; van den Oord, Joost J; Rabkin, Michael S; Schmidt, Birgitta; Shea, Christopher R; Yun, Sook Jung; Xu, George X; Piepkorn, Michael W; Elder, David E; Barnhill, Raymond L

2016-08-01

Pathologists use diverse terminology when interpreting melanocytic neoplasms, potentially compromising quality of care. We sought to evaluate the Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis (MPATH-Dx) scheme, a 5-category classification system for melanocytic lesions. Participants (n = 16) of the 2013 International Melanoma Pathology Study Group Workshop provided independent case-level diagnoses and treatment suggestions for 48 melanocytic lesions. Individual diagnoses (including, when necessary, least and most severe diagnoses) were mapped to corresponding MPATH-Dx classes. Interrater agreement and correlation between MPATH-Dx categorization and treatment suggestions were evaluated. Most participants were board-certified dermatopathologists (n = 15), age 50 years or older (n = 12), male (n = 9), based in the United States (n = 11), and primary academic faculty (n = 14). Overall, participants generated 634 case-level diagnoses with treatment suggestions. Mean weighted kappa coefficients for diagnostic agreement after MPATH-Dx mapping (assuming least and most severe diagnoses, when necessary) were 0.70 (95% confidence interval 0.68-0.71) and 0.72 (95% confidence interval 0.71-0.73), respectively, whereas correlation between MPATH-Dx categorization and treatment suggestions was 0.91. This was a small sample size of experienced pathologists in a testing situation. Varying diagnostic nomenclature can be classified into a concise hierarchy using the MPATH-Dx scheme. Further research is needed to determine whether this classification system can facilitate diagnostic concordance in general pathology practice and improve patient care. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

The predictive value of 18F-FDG PET for pathological response of primary tumor in patients with esophageal cancer during or after neoadjuvant chemoradiotherapy: a meta-analysis.

PubMed

Cong, Lihong; Wang, Shikun; Gao, Teng; Hu, Likuan

2016-12-01

We want to review the value of 18-fluoro-deoxy-glucose positron emission tomography for response prediction of primary tumor in patients with esophageal cancer during or after neoadjuvant chemoradiotherapy. Studies were searched in Pubmed, Embase and Cochrane Library with specific search strategy. The published articles were included according to the criteria established in advance. The included studies were divided into two groups according to the time of the repeat positron emission tomography: during (Group A) or after neoadjuvant chemoradiotherapy (Group B). The studies that performed the repeat positron emission tomography after neoadjuvant chemoradiotherapy were graded Quality Assessment of Diagnostic Accuracy Studies. The pooled sensitivity, specificity and diagnostic odds ratio were obtained for both groups on the basis of no-existing of threshold effect. Fifteen studies were included in the present study. The threshold effect did not exist in both groups. The pooled sensitivity, specificity and diagnostic odds ratio were 85%, 59%, 6.82 with 95% confidence interval 76-91%, 48-69%, 2.25-20.72 in Group A. The equivalent values were 67%, 69%, 6.34 with 95% confidence interval 60-73%, 63-74%, 2.08-19.34 in Group B. The pooled sensitivity was 90% in four studies that enrolled patients with esophageal squamous cell carcinoma merely in Group B. According to the present data, positron emission tomography should not be used routinely to guide treatment strategy in esophageal cancer patients. We speculated that positron emission tomography could be used as a tool to predict treatment response after neoadjuvant chemoradiotherapy in patients with esophageal squamous cell carcinoma. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Quality Assurance in the Polio Laboratory. Cell Sensitivity and Cell Authentication Assays.

PubMed

Dunn, Glynis

2016-01-01

The accuracy of poliovirus surveillance is largely dependent on the quality of the cell lines used for virus isolation, which is the foundation of poliovirus diagnostic work. Many cell lines are available for the isolation of enteroviruses, whilst genetically modified L20B cells can be used as a diagnostic tool for the identification of polioviruses. To be confident that cells can consistently isolate the virus of interest, it is necessary to have a quality assurance system in place, which will ensure that the cells in use are not contaminated with other cell lines or microorganisms and that they remain sensitive to the viruses being studied.The sensitivity of cell lines can be assessed by the regular testing of a virus standard of known titer in the cell lines used for virus isolation. The titers obtained are compared to previously obtained titers in the same assay, so that any loss of sensitivity can be detected.However, the detection of cell line cross contamination is more difficult. DNA bar coding is a technique that uses a short DNA sequence from a standardized position in the genome as a molecular diagnostic assay for species-level identification. For almost all groups of higher animals, the cytochrome c oxidase subunit 1 of mitochondrial DNA (CO1) is emerging as the standard barcode region. This region is 648 nucleotide base pairs long in most phylogenetic groups and is flanked by regions of conserved sequences, making it relatively easy to isolate and analyze. DNA barcodes vary among individuals of the same species to a very minor degree (generally less than 1-2 %), and a growing number of studies have shown that the COI sequences of even closely related species differ by several per cent, making it possible to identify different species with high confidence.

Is this elderly patient dehydrated? Diagnostic accuracy of hydration assessment using physical signs, urine, and saliva markers.

PubMed

Fortes, Matthew B; Owen, Julian A; Raymond-Barker, Philippa; Bishop, Claire; Elghenzai, Salah; Oliver, Samuel J; Walsh, Neil P

2015-03-01

Dehydration in older adults contributes to increased morbidity and mortality during hospitalization. As such, early diagnosis of dehydration may improve patient outcome and reduce the burden on healthcare. This prospective study investigated the diagnostic accuracy of routinely used physical signs, and noninvasive markers of hydration in urine and saliva. Prospective diagnostic accuracy study. Hospital acute medical care unit and emergency department. One hundred thirty older adults [59 males, 71 females, mean (standard deviation) age = 78 (9) years]. Participants with any primary diagnosis underwent a hydration assessment within 30 minutes of admittance to hospital. Hydration assessment comprised 7 physical signs of dehydration [tachycardia (>100 bpm), low systolic blood pressure (<100 mm Hg), dry mucous membrane, dry axilla, poor skin turgor, sunken eyes, and long capillary refill time (>2 seconds)], urine color, urine specific gravity, saliva flow rate, and saliva osmolality. Plasma osmolality and the blood urea nitrogen to creatinine ratio were assessed as reference standards of hydration with 21% of participants classified with water-loss dehydration (plasma osmolality >295 mOsm/kg), 19% classified with water-and-solute-loss dehydration (blood urea nitrogen to creatinine ratio >20), and 60% classified as euhydrated. All physical signs showed poor sensitivity (0%-44%) for detecting either form of dehydration, with only low systolic blood pressure demonstrating potential utility for aiding the diagnosis of water-and-solute-loss dehydration [diagnostic odds ratio (OR) = 14.7]. Neither urine color, urine specific gravity, nor saliva flow rate could discriminate hydration status (area under the receiver operating characteristic curve = 0.49-0.57, P > .05). In contrast, saliva osmolality demonstrated moderate diagnostic accuracy (area under the receiver operating characteristic curve = 0.76, P < .001) to distinguish both dehydration types (70% sensitivity, 68% specificity, OR = 5.0 (95% confidence interval 1.7-15.1) for water-loss dehydration, and 78% sensitivity, 72% specificity, OR = 8.9 (95% confidence interval 2.5-30.7) for water-and-solute-loss dehydration). With the exception of low systolic blood pressure, which could aid in the specific diagnosis of water-and-solute-loss dehydration, physical signs and urine markers show little utility to determine if an elderly patient is dehydrated. Saliva osmolality demonstrated superior diagnostic accuracy compared with physical signs and urine markers, and may have utility for the assessment of both water-loss and water-and-solute-loss dehydration in older individuals. It is particularly noteworthy that saliva osmolality was able to detect water-and-solute-loss dehydration, for which a measurement of plasma osmolality would have no diagnostic utility. Copyright © 2015 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Recent Progress in Nanomedicine: Therapeutic, Diagnostic and Theranostic Applications

PubMed Central

Rizzo, Larissa Y.; Theek, Benjamin; Storm, Gert; Kiessling, Fabian; Lammers, Twan

2013-01-01

In recent years, the use of nanomedicine formulations for therapeutic and diagnostic applications has increased exponentially. Many different systems and strategies have been developed for drug targeting to pathological sites, as well as for visualizing and quantifying important (patho-) physiological processes. In addition, ever more efforts have been undertaken to combine diagnostic and therapeutic properties within a single nanomedicine formulation. These so-called nanotheranostics are able to provide valuable information on drug delivery, drug release and drug efficacy, and they are considered to be highly useful for personalizing nanomedicine-based (chemo-) therapeutic interventions. PMID:23578464

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.

Enrichment of target sequences for next-generation sequencing applications in research and diagnostics.

PubMed

Altmüller, Janine; Budde, Birgit S; Nürnberg, Peter

2014-02-01

Abstract Targeted re-sequencing such as gene panel sequencing (GPS) has become very popular in medical genetics, both for research projects and in diagnostic settings. The technical principles of the different enrichment methods have been reviewed several times before; however, new enrichment products are constantly entering the market, and researchers are often puzzled about the requirement to take decisions about long-term commitments, both for the enrichment product and the sequencing technology. This review summarizes important considerations for the experimental design and provides helpful recommendations in choosing the best sequencing strategy for various research projects and diagnostic applications.

Confidence intervals for differences between volumes under receiver operating characteristic surfaces (VUS) and generalized Youden indices (GYIs).

PubMed

Yin, Jingjing; Nakas, Christos T; Tian, Lili; Reiser, Benjamin

2018-03-01

This article explores both existing and new methods for the construction of confidence intervals for differences of indices of diagnostic accuracy of competing pairs of biomarkers in three-class classification problems and fills the methodological gaps for both parametric and non-parametric approaches in the receiver operating characteristic surface framework. The most widely used such indices are the volume under the receiver operating characteristic surface and the generalized Youden index. We describe implementation of all methods and offer insight regarding the appropriateness of their use through a large simulation study with different distributional and sample size scenarios. Methods are illustrated using data from the Alzheimer's Disease Neuroimaging Initiative study, where assessment of cognitive function naturally results in a three-class classification setting.

37 CFR 1.14 - Patent applications preserved in confidence.

Code of Federal Regulations, 2010 CFR

2010-07-01

... section. (1) Records associated with patent applications (see paragraph (g) for international applications... invention registration, a U.S. patent application publication, or an international patent application publication of an international application that was published in accordance with PCT Article 21(2). An...

Development and Application of a Two-Tier Multiple Choice Diagnostic Instrument To Assess High School Students' Understanding of Inorganic Chemistry Qualitative Analysis.

ERIC Educational Resources Information Center

Tan, Kim Chwee Daniel; Goh, Ngoh Khang; Chia, Lian Sai; Treagust, David F.

2002-01-01

Describes the development and application of a two-tier multiple choice diagnostic instrument to assess high school students' understanding of inorganic chemistry qualitative analysis. Shows that the Grade 10 students had difficulty understanding the reactions involved in the identification of cations and anions, for example, double decomposition…

Expert systems for diagnostic purposes, prospected applications to the radar field

NASA Astrophysics Data System (ADS)

Filippi, Riccardo

Expert systems applied to fault diagnosis, particularly electrical circuit troubleshooting, are introduced. Diagnostic systems consisting of sequences of rules of the symptom-disease type (rule based system) and systems based upon a physical and functional description of the unit subjected to fault diagnosis are treated. Application of such systems to radar equipment troubleshooting, in particular to the transmitter, is discussed.

Leishmania Surveillance and Diagnostic Capability in Support of the Joint Biological Agent Identification and Diagnostic System (JBAIDS) and Leishmania Vector Surveillance

DTIC Science & Technology

2013-02-07

specific biosurveillance activities as well as clinical applications and alternative versions preformatted and categorized as ‘high-tech’ and ‘low-tech’ and...methodologies. Application for patent protection of this DoD intellectual property is underway. 1::1 . :::.u~~l-1 I ~111VI:::O Leishmaniasis...LHL assay and the need to develop novel and unique sample preparation methodologies. Application for patent protection of this DoD intellectual

Efficient fault diagnosis of helicopter gearboxes

NASA Technical Reports Server (NTRS)

Chin, H.; Danai, K.; Lewicki, D. G.

1993-01-01

Application of a diagnostic system to a helicopter gearbox is presented. The diagnostic system is a nonparametric pattern classifier that uses a multi-valued influence matrix (MVIM) as its diagnostic model and benefits from a fast learning algorithm that enables it to estimate its diagnostic model from a small number of measurement-fault data. To test this diagnostic system, vibration measurements were collected from a helicopter gearbox test stand during accelerated fatigue tests and at various fault instances. The diagnostic results indicate that the MVIM system can accurately detect and diagnose various gearbox faults so long as they are included in training.

[Laboratory diagnostics in transient loss of consciousness : Serum lactate compared to serum creatine kinase as diagnostic indicator for generalized tonic-clonic seizures].

PubMed

Dafotakis, M; Heckelmann, J; Zechbauer, S; Litmathe, J; Brokmann, J; Willmes, K; Surges, R; Matz, O

2018-03-21

Laboratory parameters can help in the differential diagnostics of acute episodes of transient loss of consciousness. Especially serum lactate and serum creatine kinase (CK) levels may provide valuable hints to distinguish generalized tonic-clonic seizures (GTCS) from syncope. Serum lactate levels at admission and CK levels 10-48 h after the episodes that led to admission were compared between patients with GTCS (n = 30) and those with syncope (n = 15). In addition, sensitivity and specificity of lactate and CK as diagnostic markers for syncope and GTCS were determined. The serum lactate and serum CK levels were significantly increased in patients with GTCS as compared to syncope patients (serum lactate: p < 0.001; CK: p < 0.005). The area under the curve (AUC) for serum lactate as an indicator for GTCS was 0.94 (95% confidence interval [CI] 0.88-1.0). For CK the receiver operating characteristics (ROC) analysis produced an AUC of only 0.77 (95% CI: 0.63-0.9). The determination of the lactate value as point-of-care diagnostics appears to be highly relevant in the rapid clarification of unclear episodes with transient loss of consciousness. The CK level at follow-up is also suitable for distinguishing GTCS from syncope but is inferior to the serum lactate value.

A new diagnostic method for separating airborne and structureborne noise radiated by plates with applications for propeller driven aircraft

NASA Technical Reports Server (NTRS)

Mcgary, Michael C.

1988-01-01

The anticipated application of advanced turboprop propulsion systems is expected to increase the interior noise of future aircraft to unacceptably high levels. The absence of technically and economically feasible noise source-path diagnostic tools has been a prime obstacle in the development of efficient noise control treatments for propeller-driven aircraft. A new diagnostic method that permits the separation and prediction of the fully coherent airborne and structureborne components of the sound radiated by plates or thin shells has been developed. Analytical and experimental studies of the proposed method were performed on an aluminum plate. The results of the study indicate that the proposed method could be used in flight, and has fewer encumbrances than the other diagnostic tools currently available.

Development of life prediction capabilities for liquid propellant rocket engines. Post-fire diagnostic system for the SSME system architecture study

NASA Technical Reports Server (NTRS)

Gage, Mark; Dehoff, Ronald

1991-01-01

This system architecture task (1) analyzed the current process used to make an assessment of engine and component health after each test or flight firing of an SSME, (2) developed an approach and a specific set of objectives and requirements for automated diagnostics during post fire health assessment, and (3) listed and described the software applications required to implement this system. The diagnostic system described is a distributed system with a database management system to store diagnostic information and test data, a CAE package for visual data analysis and preparation of plots of hot-fire data, a set of procedural applications for routine anomaly detection, and an expert system for the advanced anomaly detection and evaluation.

Application of the McDonald criteria in Latin America

PubMed Central

2017-01-01

The diagnosis of multiple sclerosis (MS) is based on neurological symptoms and signs, alongside evidence of dissemination of central nervous system (CNS) lesions in space and time. In the absence of a sensitive and specific diagnostic test, diagnostic criteria are needed for diagnosing MS. The caveat to the application of the McDonald criteria is that alternative diagnoses must be excluded. The prevalence, clinical phenotype and the differential diagnosis of MS may have variations in different populations, especially in Latin America (LATAM). Considering that MS diagnostic criteria were developed with data gathered largely from adult Caucasian European and North American populations, their applicability and accuracy in ethnical/genetic diverse populations may be affected. There are scarce data in our region about the reliability of MS criteria. PMID:28979793

Incremental Validity of Multidimensional Proficiency Scores from Diagnostic Classification Models: An Illustration for Elementary School Mathematics

ERIC Educational Resources Information Center

Kunina-Habenicht, Olga; Rupp, André A.; Wilhelm, Oliver

2017-01-01

Diagnostic classification models (DCMs) hold great potential for applications in summative and formative assessment by providing discrete multivariate proficiency scores that yield statistically driven classifications of students. Using data from a newly developed diagnostic arithmetic assessment that was administered to 2032 fourth-grade students…

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.

Does Wearable Medical Technology With Video Recording Capability Add Value to On-Call Surgical Evaluations?

PubMed

Gupta, Sameer; Boehme, Jacqueline; Manser, Kelly; Dewar, Jannine; Miller, Amie; Siddiqui, Gina; Schwaitzberg, Steven D

2016-10-01

Background Google Glass has been used in a variety of medical settings with promising results. We explored the use and potential value of an asynchronous, near-real time protocol-which avoids transmission issues associated with real-time applications-for recording, uploading, and viewing of high-definition (HD) visual media in the emergency department (ED) to facilitate remote surgical consults. Study Design First-responder physician assistants captured pertinent aspects of the physical examination and diagnostic imaging using Google Glass' HD video or high-resolution photographs. This visual media were then securely uploaded to the study website. The surgical consultation then proceeded over the phone in the usual fashion and a clinical decision was made. The surgeon then accessed the study website to review the uploaded video. This was followed by a questionnaire regarding how the additional data impacted the consultation. Results The management plan changed in 24% (11) of cases after surgeons viewed the video. Five of these plans involved decision making regarding operative intervention. Although surgeons were generally confident in their initial management plan, confidence scores increased further in 44% (20) of cases. In addition, we surveyed 276 ED patients on their opinions regarding concerning the practice of health care providers wearing and using recording devices in the ED. The survey results revealed that the majority of patients are amenable to the addition of wearable technology with video functionality to their care. Conclusions This study demonstrates the potential value of a medically dedicated, hands-free, HD recording device with internet connectivity in facilitating remote surgical consultation. © The Author(s) 2016.

Systematic review of patient history and physical examination to diagnose chronic low back pain originating from the facet joints.

PubMed

Maas, E T; Juch, J N S; Ostelo, R W J G; Groeneweg, J G; Kallewaard, J W; Koes, B W; Verhagen, A P; Huygen, F J P M; van Tulder, M W

2017-03-01

Patient history and physical examination are frequently used procedures to diagnose chronic low back pain (CLBP) originating from the facet joints, although the diagnostic accuracy is controversial. The aim of this systematic review is to determine the diagnostic accuracy of patient history and/or physical examination to identify CLBP originating from the facet joints using diagnostic blocks as reference standard. We searched MEDLINE, EMBASE, CINAHL, Web of Science and the Cochrane Collaboration database from inception until June 2016. Two review authors independently selected studies for inclusion, extracted data and assessed the risk of bias. We calculated sensitivity and specificity values, with 95% confidence intervals (95% CI). Twelve studies were included, in which 129 combinations of index tests and reference standards were presented. Most of these index tests have only been evaluated in single studies with a high risk of bias. Four studies evaluated the diagnostic accuracy of the Revel's criteria combination. Because of the clinical heterogeneity, results were not pooled. The published sensitivities ranged from 0.11 (95% CI 0.02-0.29) to 1.00 (95% CI 0.75-1.00), and the specificities ranged from 0.66 (95% CI 0.46-0.82) to 0.91 (95% CI 0.83-0.96). Due to clinical heterogeneity, the evidence for the diagnostic accuracy of patient history and/or physical examination to identify facet joint pain is inconclusive. Patient history and physical examination cannot be used to limit the need of a diagnostic block. The validity of the diagnostic facet joint block should be studied, and high quality studies are required to confirm the results of single studies. Patient history and physical examination cannot be used to limit the need of a diagnostic block. The validity of the diagnostic facet joint block should be studied, and high quality studies are required to confirm the results of single studies. © 2016 European Pain Federation - EFIC®.

The impact of new trends in POCTs for companion diagnostics, non-invasive testing and molecular diagnostics.

PubMed

Huckle, David

2015-06-01

Point-of-care diagnostics have been slowly developing over several decades and have taken on a new importance in current healthcare delivery for both diagnostics and development of new drugs. Molecular diagnostics have become a key driver of technology change and opened up new areas in companion diagnostics for use alongside pharmaceuticals and in new clinical approaches such as non-invasive testing. Future areas involving smartphone and other information technology advances, together with new developments in molecular biology, microfluidics and surface chemistry are adding to advances in the market. The focus for point-of-care tests with molecular diagnostic technologies is focused on advancing effective applications.

3D T2-weighted and Gd-EOB-DTPA-enhanced 3D T1-weighted MR cholangiography for evaluation of biliary anatomy in living liver donors.

PubMed

Cai, Larry; Yeh, Benjamin M; Westphalen, Antonio C; Roberts, John; Wang, Zhen J

2017-03-01

To investigate whether the addition of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced 3D T1-weighted MR cholangiography (T1w-MRC) to 3D T2-weighted MRC (T2w-MRC) improves the confidence and diagnostic accuracy of biliary anatomy in living liver donors. Two abdominal radiologists retrospectively and independently reviewed pre-operative MR studies in 58 consecutive living liver donors. The second-order bile duct visualization on T1w- and T2w-MRC images was rated on a 4-point scale. The readers also independently recorded the biliary anatomy and their diagnostic confidence using (1) combined T1w- and T2w-MRC, and (2) T2w-MRC. In the 23 right lobe donors, the biliary anatomy at imaging and the imaging-predicted number of duct orifices at surgery were compared to intra-operative findings. T1w-MRC had a higher proportion of excellent visualization than T2w-MRC, 66% vs. 45% for reader 1 and 60% vs. 31% for reader 2. The median confidence score for biliary anatomy diagnosis was significantly higher with combined T1w- and T2w-MRC than T2w-MRC alone for both readers (Reader 1: 3 vs. 2, p < 0.001; Reader 2: 3 vs. 1, p < 0.001). Compared to intra-operative findings, the accuracy of imaging-predicted number of duct orifices using combined T1w-and T2w-MRC was significantly higher than that using T2w-MRC alone (p = 0.034 for reader 1, p = 0.0082 for reader 2). The addition of Gd-EOB-DTPA-enhanced 3D T1w-MRC to 3D T2w-MRC improves second-order bile duct visualization and increases the confidence in biliary anatomy diagnosis and the accuracy in the imaging-predicted number of duct orifices acquired during right lobe harvesting.

Multi-spectral fiber spectroscopy in 0,4-16μm range for biomedical applications(Conference Presentation)

NASA Astrophysics Data System (ADS)

Artyushenko, Viacheslav

2017-02-01

Various biomedical applications of fiber optics in a broad spectral range 0,4-16μm span from endoscopic imaging and Photo Dynamic Diagnostics (PDD) to laser power delivery for minimal invasive laser surgery, tissue coagulation and welding, Photo Dynamic Therapy (PDT), etc. Present review will highlight the latest results in advanced fiber solutions for a precise tissue diagnostics and control of some therapy methods - for so called "theranostic". Spectral fiber sensing for label free analysis of tissue composition helps to differentiate malignant and normal tissue to secure minimal invasive, but complete tumor removal or treatment. All key methods of Raman, fluorescence, diffuse reflection & MIR-absorption spectroscopy will be compared when used for the same spot of tissue - to select the most specific, sensitive and accurate method or to combine them for the synergy enhanced effect. The most informative spectral features for distinct organs/ tumor can be used to design special fiber sensors to be developed for portable and low cost applications with modern IT-features. Examples of multi-spectral tissue diagnostics promising for the future clinical applications will be presented to enable reduced mortality from cancer in the future. Translation of described methods into clinical practice will be discussed in comparison with the other method of optical diagnostics which should enhance modern medicine by less invasive, more precise and more effective methods of therapy to be fused with in-vivo diagnostics sensors & systems.

Diagnostic value of 3D time-of-flight MRA in trigeminal neuralgia.

PubMed

Cai, Jing; Xin, Zhen-Xue; Zhang, Yu-Qiang; Sun, Jie; Lu, Ji-Liang; Xie, Feng

2015-08-01

The aim of this meta-analysis was to evaluate the diagnostic value of 3D time-of-flight magnetic resonance angiography (3D-TOF-MRA) in trigeminal neuralgia (TN). Relevant studies were identified by computerized database searches supplemented by manual search strategies. The studies were included in accordance with stringent inclusion and exclusion criteria. Following a multistep screening process, high quality studies related to the diagnostic value of 3D-TOF-MRA in TN were selected for meta-analysis. Statistical analyses were conducted using Statistical Analysis Software (version 8.2; SAS Institute, Cary, NC, USA) and Meta Disc (version 1.4; Unit of Clinical Biostatistics, Ramon y Cajal Hospital, Madrid, Spain). For the present meta-analysis, we initially retrieved 95 studies from database searches. A total of 13 studies were eventually enrolled containing a combined total of 1084 TN patients. The meta-analysis results demonstrated that the sensitivity and specificity of the diagnostic value of 3D-TOF-MRA in TN were 95% (95% confidence interval [CI] 0.93-0.96) and 77% (95% CI 0.66-0.86), respectively. The pooled positive likelihood ratio and negative likelihood ratio were 2.72 (95% CI 1.81-4.09) and 0.08 (95% CI 0.06-0.12), respectively. The pooled diagnostic odds ratio of 3D-TOF-MRA in TN was 52.92 (95% CI 26.39-106.11), and the corresponding area under the curve in the summary receiver operating characteristic curve based on the 3D-TOF-MRA diagnostic image of observers was 0.9695 (standard error 0.0165). Our results suggest that 3D-TOF-MRA has excellent sensitivity and specificity as a diagnostic tool for TN, and that it can accurately identify neurovascular compression in TN patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of urinary tract infection rates among 2- to 12-month-old febrile infants with RSV infections using 1999 and 2011 AAP diagnostic criteria.

PubMed

Kaluarachchi, Dinushan; Kaldas, Virginia; Roques, Euripedes; Nunez, Randolph; Mendez, Magda

2014-07-01

Infants with RSV infections have been found to have a clinically significant rate of urinary tract infections (UTIs). The American Academy of Pediatrics (AAP) published a revised Clinical Practice Guideline on UTIs in 2011, which includes major changes in diagnostic criteria for UTIs. Past research has been done using previous diagnostic criteria. The objective of the study is to assess the rate of UTIs in febrile infants with respiratory syncytial virus (RSV) infections according to the 2011 revised AAP Diagnostic Criteria and compare the rate of UTIs against the 1999 AAP Diagnostic Criteria. A retrospective comparative study of febrile infants (2-12 months) with RSV infections admitted to the Inpatient Pediatric unit of Lincoln Medical and Mental Center, Bronx, NY, from September through April 2006 to 2012. We applied the AAP's 1999 and 2011 diagnostic criteria for UTIs separately to assess the rates of UTIs. A total of 359 RSV-positive febrile patients who were investigated for UTIs were enrolled. Pyuria was found in 11.1% (40/359), positive urine culture 10 000 to 50 000 was found in 1.4% (5/359) and ≥50 000 in 4.7% (17/359). The rate of UTIs using AAP's 1999 criteria was 6.1% (22/359), and using the 2011 criteria the rate was 1.1% (4/359). The rate of UTIs was significantly different between the 2 groups (odds ratio [confidence interval] = 0.17 [0.05, 0.5], P = .001). The rate of UTIs in RSV-positive febrile infants is very low (1.1%) with the 2011 AAP diagnostic criteria. Previously described increased risk of UTIs may represent asymptomatic bacteriuria or contaminated specimens. © The Author(s) 2014.

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.

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.

The diagnostic test accuracy of magnetic resonance imaging, magnetic resonance arthrography and computer tomography in the detection of chondral lesions of the hip.

PubMed

Smith, Toby O; Simpson, Michael; Ejindu, Vivian; Hing, Caroline B

2013-04-01

The purpose of this study was to assess the diagnostic test accuracy of magnetic resonance imaging (MRI), magnetic resonance arthrography (MRA) and multidetector arrays in CT arthrography (MDCT) for assessing chondral lesions in the hip joint. A review of the published and unpublished literature databases was performed to identify all studies reporting the diagnostic test accuracy (sensitivity/specificity) of MRI, MRA or MDCT for the assessment of adults with chondral (cartilage) lesions of the hip with surgical comparison (arthroscopic or open) as the reference test. All included studies were reviewed using the quality assessment of diagnostic accuracy studies appraisal tool. Pooled sensitivity, specificity, likelihood ratios and diagnostic odds ratios were calculated with 95 % confidence intervals using a random-effects meta-analysis for MRI, MRA and MDCT imaging. Eighteen studies satisfied the eligibility criteria. These included 648 hips from 637 patients. MRI indicated a pooled sensitivity of 0.59 (95 % CI: 0.49-0.70) and specificity of 0.94 (95 % CI: 0.90-0.97), and MRA sensitivity and specificity values were 0.62 (95 % CI: 0.57-0.66) and 0.86 (95 % CI: 0.83-0.89), respectively. The diagnostic test accuracy for the detection of hip joint cartilage lesions is currently superior for MRI compared with MRA. There were insufficient data to perform meta-analysis for MDCT or CTA protocols. Based on the current limited diagnostic test accuracy of the use of magnetic resonance or CT, arthroscopy remains the most accurate method of assessing chondral lesions in the hip joint.

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 the Amsler grid and the preferential hyperacuity perimetry in the screening of patients with age-related macular degeneration: systematic review and meta-analysis.

PubMed

Faes, L; Bodmer, N S; Bachmann, L M; Thiel, M A; Schmid, M K

2014-07-01

To clarify the screening potential of the Amsler grid and preferential hyperacuity perimetry (PHP) in detecting or ruling out wet age-related macular degeneration (AMD). Medline, Scopus and Web of Science (by citation of reference) were searched. Checking of reference lists of review articles and of included articles complemented electronic searches. Papers were selected, assessed, and extracted in duplicate. Systematic review and meta-analysis. Twelve included studies enrolled 903 patients and allowed constructing 27 two-by-two tables. Twelve tables reported on the Amsler grid and its modifications, twelve tables reported on the PHP, one table assessed the MCPT and two tables assessed the M-charts. All but two studies had a case-control design. The pooled sensitivity of studies assessing the Amsler grid was 0.78 (95% confidence intervals; 0.64-0.87), and the pooled specificity was 0.97 (95% confidence intervals; 0.91-0.99). The corresponding positive and negative likelihood ratios were 23.1 (95% confidence intervals; 8.4-64.0) and 0.23 (95% confidence intervals; 0.14-0.39), respectively. The pooled sensitivity of studies assessing the PHP was 0.85 (95% confidence intervals; 0.80-0.89), and specificity was 0.87 (95% confidence intervals; 0.82-0.91). The corresponding positive and negative likelihood ratios were 6.7 (95% confidence intervals; 4.6-9.8) and 0.17 (95% confidence intervals; 0.13-0.23). No pooling was possible for MCPT and M-charts. Results from small preliminary studies show promising test performance characteristics both for the Amsler grid and PHP to rule out wet AMD in the screening setting. To what extent these findings can be transferred to a real clinic practice still needs to be established.

Computational circular dichroism estimation for point-of-care diagnostics via vortex half-wave retarders

NASA Astrophysics Data System (ADS)

Haider, Shahid A.; Tran, Megan Y.; Wong, Alexander

2018-02-01

Observing the circular dichroism (CD) caused by organic molecules in biological fluids can provide powerful indicators of patient health and provide diagnostic clues for treatment. Methods for this kind of analysis involve tabletop devices that weigh tens of kilograms with costs on the order of tens of thousands of dollars, making them prohibitive in point-of-care diagnostic applications. In an e ort to reduce the size, cost, and complexity of CD estimation systems for point-of-care diagnostics, we propose a novel method for CD estimation that leverages a vortex half-wave retarder in between two linear polarizers and a two-dimensional photodetector array to provide an overall complexity reduction in the system. This enables the measurement of polarization variations across multiple polarizations after they interact with a biological sample, simultaneously, without the need for mechanical actuation. We further discuss design considerations of this methodology in the context of practical applications to point-of-care diagnostics.

Laser-plasma interaction experiments and diagnostics at NRL (Naval Research Laboratory). Memorandum report

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

Ripin, B.H.; Grun, J.; Herbst, M.J.

Laser plasma interaction experiments have now advanced to the point where very quantitative measurements are required to elucidate the physic issues important for laser fusion and other applications. Detailed time-resolved knowledge of the plasma density, temperature, velocity gradients, spatial structure, heat flow characteristics, radiation emission, etc, are needed over tremendou ranges of plasma density and temperature. Moreover, the time scales are very short, aggrevating the difficulty of the measurements further. Nonetheless, such substantial progress has been made in diagnostic development during the past few years that we are now able to do well diagnosed experiments. In this paper the authorsmore » review recent diagnostic developments for laser-plasma interactions, outline their regimes of applicability, and show examples of their utility. In addition to diagnostics for the high densities and temperature characteristic of laser fusion physics studies, diagnostics designed to study the two-stream interactions of laser created plasma flowing through an ambient low density plasma will be described.« less

Keeping up with the times: revising the dermatology residency curriculum in the era of molecular diagnostics and personalized medicine.

PubMed

LaChance, Avery; Murphy, Michael J

2014-11-01

The clinical use of molecular diagnostics, genomics, and personalized medicine is increasing and improving rapidly over time. However, medical education incorporating the practical application of these techniques is lagging behind. Although instruction in these areas should be expanded upon and improved at all levels of training, residency provides a concentrated period of time in which to hone in on skills that are practically applicable to a trainee's specialty of choice. Although residencies in some fields, such as pathology, have begun to incorporate practical molecular diagnostics training, this area remains a relative gap in dermatology residency programs. Herein, we advocate for the incorporation of training in molecular diagnostics and personalized medicine into dermatology residency programs and propose a basic curriculum template for how to begin approaching these topics. By incorporating molecular diagnostics into dermatology residency training, dermatologists have the opportunity to lead the way and actively shape the specialty's transition into the era of personalized medicine. © 2014 The International Society of Dermatology.

Array-based disease diagnostics using lipid/polydiacetylene vesicles encapsulated in a sol-gel matrix.

PubMed

Kolusheva, S; Yossef, R; Kugel, A; Katz, M; Volinsky, R; Welt, M; Hadad, U; Drory, V; Kliger, M; Rubin, E; Porgador, A; Jelinek, R

2012-07-17

We demonstrate a novel array-based diagnostic platform comprising lipid/polydiacetylene (PDA) vesicles embedded within a transparent silica-gel matrix. The diagnostic scheme is based upon the unique chromatic properties of PDA, which undergoes blue-red transformations induced by interactions with amphiphilic or membrane-active analytes. We show that constructing a gel matrix array hosting PDA vesicles with different lipid compositions and applying to blood plasma obtained from healthy individuals and from patients suffering from disease, respectively, allow distinguishing among the disease conditions through application of a simple machine-learning algorithm, using the colorimetric response of the lipid/PDA/gel matrix as the input. Importantly, the new colorimetric diagnostic approach does not require a priori knowledge on the exact metabolite compositions of the blood plasma, since the concept relies only on identifying statistically significant changes in overall disease-induced chromatic response. The chromatic lipid/PDA/gel array-based "fingerprinting" concept is generic, easy to apply, and could be implemented for varied diagnostic and screening applications.

Design and development of a simple UV fluorescence multi-spectral imaging system

NASA Astrophysics Data System (ADS)

Tovar, Carlos; Coker, Zachary; Yakovlev, Vladislav V.

2018-02-01

Healthcare access in low-resource settings is compromised by the availability of affordable and accurate diagnostic equipment. The four primary poverty-related diseases - AIDS, pneumonia, malaria, and tuberculosis - account for approximately 400 million annual deaths worldwide as of 2016 estimates. Current diagnostic procedures for these diseases are prolonged and can become unreliable under various conditions. We present the development of a simple low-cost UV fluorescence multi-spectral imaging system geared towards low resource settings for a variety of biological and in-vitro applications. Fluorescence microscopy serves as a useful diagnostic indicator and imaging tool. The addition of a multi-spectral imaging modality allows for the detection of fluorophores within specific wavelength bands, as well as the distinction between fluorophores possessing overlapping spectra. The developed instrument has the potential for a very diverse range of diagnostic applications in basic biomedical science and biomedical diagnostics and imaging. Performance assessment of the microscope will be validated with a variety of samples ranging from organic compounds to biological samples.

Diagnostic change and the increased prevalence of autism

PubMed Central

King, Marissa; Bearman, Peter

2009-01-01

Background Increased autism prevalence rates have generated considerable concern. However, the contribution of changes in diagnostic practices to increased prevalence rates has not been thoroughly examined. Debates over the role of diagnostic substitution also continue. California has been an important test case in these controversies. The objective of this study was to determine the extent to which the increased prevalence of autism in California has been driven by changes in diagnostic practices, diagnostic substitution and diagnostic accretion. Methods Retrospective case record examination of 7003 patients born before 1987 with autism who were enrolled with the California Department of Developmental Services between 1992 and 2005 was carried out. Of principal interest were 631 patients with a sole diagnosis of mental retardation (MR) who subsequently acquired a diagnosis of autism. The outcome of interest was the probability of acquiring a diagnosis of autism as a result of changes in diagnostic practices was calculated. The probability of diagnostic change is then used to model the proportion of the autism caseload arising from changing diagnostic practices. Results The odds of a patient acquiring an autism diagnosis were elevated in periods in which the practices for diagnosing autism changed. The odds of change in years in which diagnostic practices changed were 1.68 [95% confidence interval (CI) 1.11–2.54], 1.55 (95% CI 1.03–2.34), 1.58 (95% CI 1.05–2.39), 1.82 (95% CI 1.23–2.7) and 1.61 (95% CI 1.09–2.39). Using the probability of change between 1992 and 2005 to generalize to the population with autism, it is estimated that 26.4% (95% CI 16.25–36.48) of the increased autism caseload in California is uniquely associated with diagnostic change through a single pathway—individuals previously diagnosed with MR. Conclusion Changes in practices for diagnosing autism have had a substantial effect on autism caseloads, accounting for one-quarter of the observed increase in prevalence in California between 1992 and 2005. PMID:19737791

Brain magnetic resonance imaging: perception and expectations of neurologists, neurosurgeons and psychiatrists.

PubMed

Branco, Paulo; Ayres-Basto, Margarida; Portugal, Pedro; Ramos, Isabel; Seixas, Daniela

2014-06-01

Magnetic resonance imaging (MRI) has rapidly become an essential diagnostic tool in modern medicine. Understanding the objectives, perception and expectations of the different medical specialties towards MRI is therefore important to improve the quality of the examinations. Our aim was to better comprehend the reasons and expectations of neurologists, neurosurgeons and psychiatrists when requesting brain MRI scans for their patients, and also to perceive the degree of confidence of these specialists in the images and respective reports. Sixty-three specialists were recruited from two tertiary hospitals and answered a tailored questionnaire. Neurosurgeons were more concerned with the images themselves; neurologists lacked confidence in both MRI images and reports, and one third of the psychiatrists only read the report and were the most confident of the specialties in MRI findings. These results possibly reflect the idiosyncrasies of each of these medical specialties. This knowledge, driven by efficient communication between neuroradiologists and neurosurgeons, neurologists and psychiatrists, may contribute to improve the quality of MRI examinations and consequently patient care and management of health resources.

Brain Magnetic Resonance Imaging: Perception and Expectations of Neurologists, Neurosurgeons and Psychiatrists

PubMed Central

Branco, Paulo; Ayres-Basto, Margarida; Portugal, Pedro; Ramos, Isabel; Seixas, Daniela

2014-01-01

Summary Magnetic resonance imaging (MRI) has rapidly become an essential diagnostic tool in modern medicine. Understanding the objectives, perception and expectations of the different medical specialties towards MRI is therefore important to improve the quality of the examinations. Our aim was to better comprehend the reasons and expectations of neurologists, neurosurgeons and psychiatrists when requesting brain MRI scans for their patients, and also to perceive the degree of confidence of these specialists in the images and respective reports. Sixty-three specialists were recruited from two tertiary hospitals and answered a tailored questionnaire. Neurosurgeons were more concerned with the images themselves; neurologists lacked confidence in both MRI images and reports, and one third of the psychiatrists only read the report and were the most confident of the specialties in MRI findings. These results possibly reflect the idiosyncrasies of each of these medical specialties. This knowledge, driven by efficient communication between neuroradiologists and neurosurgeons, neurologists and psychiatrists, may contribute to improve the quality of MRI examinations and consequently patient care and management of health resources. PMID:24976192

Pre- and postoperative assessment of sinus grafting procedures using cone-beam computed tomography compared with panoramic radiographs.

PubMed

Baciut, Mihaela; Hedesiu, Mihaela; Bran, Simion; Jacobs, Reinhilde; Nackaerts, Olivia; Baciut, Grigore

2013-05-01

The present study evaluated the clinical validity of cone-beam computed tomography (CBCT) scans in comparison to panoramic radiographs regarding preoperative implant planning in combination with sinus grafting procedures. Preoperative assessment of the maxillary sinuses and implant planning using panoramic radiographs and CBCT scans was performed on 16 sinuses (13 patients) and comprised choice of treatment, timing of implant placement, sinus morphology, level of confidence, complication prediction and graft volume assessment. Six examiners were involved in the study. In the majority of cases there was a concordance between the treatment type based on either panoramic radiographs or CBCT. If any difference was found, this was due to an overestimation of bone quantity and quality on panoramic radiographs. The assessment of sinus morphology showed a significantly higher detection rate of sinus mucosal hypertrophy on CBCT. The most appealing result is a significant increase in surgical confidence and a significantly better prediction of complications when using CBCT. A preoperative planning based on CBCT seems to improve sinus diagnostics and surgical confidence. © 2012 John Wiley & Sons A/S.

How do swine practitioners and veterinary pathologists arrive at a diagnosis of Clostridium perfringens type A enteritis in neonatal piglets?

PubMed Central

Chan, Gloria; Farzan, Abdolvahab; Prescott, John F.; Friendship, Robert

2013-01-01

A questionnaire was administered to 22 veterinary practitioners and 17 veterinary pathologists to investigate the methods used for diagnosis of Clostridium perfringens type A enteritis in neonatal pigs. Practitioners generally diagnosed C. perfringens type A associated enteritis by age of onset of diarrhea (between 1 to 7 days of age). Most practitioners (95%) were moderately to very confident in their diagnosis. Pathologists generally diagnosed C. perfringens type A associated enteritis by combinations of isolation of the organism, genotyping or detecting the toxins of the organism, and ruling out other pathogens through histopathology. Almost half (41%) of the pathologists were not confident of their diagnosis. This study reports that the current diagnostic method for C. perfringens type A enteritis is not specific, and although many pathologists expressed reservations about making a diagnosis of C. perfringens type A enteritis, most practitioners were confident in their diagnosis, even though reported clinical signs of clostridial diarrhea are similar to those of a number of other enteric diseases. PMID:24155437

Evaluation of prospective motion correction of high-resolution 3D-T2-FLAIR acquisitions in epilepsy patients.

PubMed

Vos, Sjoerd B; Micallef, Caroline; Barkhof, Frederik; Hill, Andrea; Winston, Gavin P; Ourselin, Sebastien; Duncan, John S

2018-03-02

T2-FLAIR is the single most sensitive MRI contrast to detect lesions underlying focal epilepsies but 3D sequences used to obtain isotropic high-resolution images are susceptible to motion artefacts. Prospective motion correction (PMC) - demonstrated to improve 3D-T1 image quality in a pediatric population - was applied to high-resolution 3D-T2-FLAIR scans in adult epilepsy patients to evaluate its clinical benefit. Coronal 3D-T2-FLAIR scans were acquired with a 1mm isotropic resolution on a 3T MRI scanner. Two expert neuroradiologists reviewed 40 scans without PMC and 40 with navigator-based PMC. Visual assessment addressed six criteria of image quality (resolution, SNR, WM-GM contrast, intensity homogeneity, lesion conspicuity, diagnostic confidence) on a seven-point Likert scale (from non-diagnostic to outstanding). SNR was also objectively quantified within the white matter. PMC scans had near-identical scores on the criteria of image quality to non-PMC scans, with the notable exception that intensity homogeneity was generally worse. Using PMC, the percentage of scans with bad image quality was substantially lower than without PMC (3.25% vs. 12.5%) on the other five criteria. Quantitative SNR estimates revealed that PMC and non-PMC had no significant difference in SNR (P=0.07). Application of prospective motion correction to 3D-T2-FLAIR sequences decreased the percentage of low-quality scans, reducing the number of scans that need to be repeated to obtain clinically useful data. Copyright © 2018 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

Assessing the educational needs of Canadian gastroenterologists and gastroenterology nurses: challenges to optimal care in Crohn's Disease.

PubMed

Dupuis, Martin; Marshall, John K; Hayes, Sean M; Cytryn, Kayla; Murray, Suzanne

2009-12-01

A national needs assessment of Canadian gastroenterologists and gastroenterology nurses was undertaken to determine the perceived and unperceived educational and performance barriers to caring for patients with Crohn's disease (CD). A triangulated, mixed-method approach (qualitative and quantitative) was used to determine the nature and extent of knowledge gaps and barriers in the care of patients with CD. Qualitative interviews were conducted with nine gastroenterologists, four gastroenterology nurses and nine patients with CD. Based on this exploratory research, a survey was designed and launched nationally (37 gastroenterologists, 36 gastroenterology nurses). Findings indicated that Canadian gastroenterologists and gastroenterology nurses lacked clarity regarding their roles and responsibilities across the continuum of CD care, and face communication gaps within the health care team, undermining their effectiveness. Gastroenterologists identified challenges in optimal diagnosis due to unclear testing and diagnostic criteria. They recognized knowledge gaps when treating patient subgroups and in prescribing biological therapies. Furthermore, gastroenterologists self-identified gaps in skill, knowledge, and confidence in monitoring disease progression and effectively assessing response to therapy. When managing patients with CD, gastroenterologists expressed challenges with patient issues outside their domain of medical expertise, particularly with the skills needed to facilitate effective patient communication and education that would enhance adherence to recommended treatments. Educational initiatives should address diagnostic and treatment guidelines, as well as enhancement of clinical performance gaps in health care team processes and the patient-professional therapeutic relationship. To impact care and patient outcomes, these initiatives must be relevant to clinical practice settings and applicable to the practice context.

Assessing the educational needs of Canadian gastroenterologists and gastroenterology nurses: Challenges to optimal care in Crohn’s disease

PubMed Central

Dupuis, Martin; Marshall, John K; Hayes, Sean M; Cytryn, Kayla; Murray, Suzanne

2009-01-01

OBJECTIVE: A national needs assessment of Canadian gastroenterologists and gastroenterology nurses was undertaken to determine the perceived and unperceived educational and performance barriers to caring for patients with Crohn’s disease (CD). METHODS: A triangulated, mixed-method approach (qualitative and quantitative) was used to determine the nature and extent of knowledge gaps and barriers in the care of patients with CD. RESULTS: Qualitative interviews were conducted with nine gastroenterologists, four gastroenterology nurses and nine patients with CD. Based on this exploratory research, a survey was designed and launched nationally (37 gastroenterologists, 36 gastroenterology nurses). Findings indicated that Canadian gastroenterologists and gastroenterology nurses lacked clarity regarding their roles and responsibilities across the continuum of CD care, and face communication gaps within the health care team, undermining their effectiveness. Gastroenterologists identified challenges in optimal diagnosis due to unclear testing and diagnostic criteria. They recognized knowledge gaps when treating patient subgroups and in prescribing biological therapies. Furthermore, gastroenterologists self-identified gaps in skill, knowledge, and confidence in monitoring disease progression and effectively assessing response to therapy. When managing patients with CD, gastroenterologists expressed challenges with patient issues outside their domain of medical expertise, particularly with the skills needed to facilitate effective patient communication and education that would enhance adherence to recommended treatments. CONCLUSIONS: Educational initiatives should address diagnostic and treatment guidelines, as well as enhancement of clinical performance gaps in health care team processes and the patient-professional therapeutic relationship. To impact care and patient outcomes, these initiatives must be relevant to clinical practice settings and applicable to the practice context. PMID:20011732

Nanotechnology in Diagnostics and Therapeutics for Gastrointestinal Disorders

PubMed Central

Laroui, Hamed; Rakhya, Poonam; Xiao, Bo; Viennois, Emilie; Merlin, Didier

2013-01-01

This review describes the state of art in nanoparticle and nanodevice applications for medical diagnosis and disease treatment. Nanodevices, such as cantilevers, have been integrated into high-sensitivity disease marker diagnostic detectors and devices, are stable over long periods of time, and display reliable performance properties. Nanotechnology strategies have been applied to therapeutic purposes as well. For example, nanoparticle-based delivery systems have been developed to protect drugs from degradation, thereby reducing the required dose and dose frequency, improving patient comfort and convenience during treatment, and reducing treatment expenses. The main objectives for integrating nanotechnologies into diagnostic and therapeutic applications in the context of intestinal diseases are reviewed. PMID:23660079

Calculation of upper confidence bounds on proportion of area containing not-sampled vegetation types: An application to map unit definition for existing vegetation maps

Treesearch

Paul L. Patterson; Mark Finco

2011-01-01

This paper explores the information forest inventory data can produce regarding forest types that were not sampled and develops the equations necessary to define the upper confidence bounds on not-sampled forest types. The problem is reduced to a Bernoulli variable. This simplification allows the upper confidence bounds to be calculated based on Cochran (1977)....

The Applicability of Confidence Intervals of Quantiles for the Generalized Logistic Distribution

NASA Astrophysics Data System (ADS)

Shin, H.; Heo, J.; Kim, T.; Jung, Y.

2007-12-01

The generalized logistic (GL) distribution has been widely used for frequency analysis. However, there is a little study related to the confidence intervals that indicate the prediction accuracy of distribution for the GL distribution. In this paper, the estimation of the confidence intervals of quantiles for the GL distribution is presented based on the method of moments (MOM), maximum likelihood (ML), and probability weighted moments (PWM) and the asymptotic variances of each quantile estimator are derived as functions of the sample sizes, return periods, and parameters. Monte Carlo simulation experiments are also performed to verify the applicability of the derived confidence intervals of quantile. As the results, the relative bias (RBIAS) and relative root mean square error (RRMSE) of the confidence intervals generally increase as return period increases and reverse as sample size increases. And PWM for estimating the confidence intervals performs better than the other methods in terms of RRMSE when the data is almost symmetric while ML shows the smallest RBIAS and RRMSE when the data is more skewed and sample size is moderately large. The GL model was applied to fit the distribution of annual maximum rainfall data. The results show that there are little differences in the estimated quantiles between ML and PWM while distinct differences in MOM.

Attitudes toward the physical examination: a comparison of U.S. and Dominican medical students.

PubMed

Fagan, Mark J; Lucero, Monica L; Wu, Edward H; Diaz, Joseph A; Reinert, Steven E

2006-01-01

Little information exists regarding whether medical students learning in relatively resource-scarce countries develop greater confidence in their physical examination skills or whether, compared to U.S. medical students, they have more positive attitudes regarding the utility of the physical examination. To compare U.S. And Dominican medical students' attitudes toward the physical examination. We surveyed final-year students at 1 medical school in the United States and 1 in the Dominican Republic regarding self-confidence in and perceived utility of the physical examination. Using 5-point Likert-type scales with response choices ranging from 1 (not at all confident) to 5 (very confident) and 1 (not at all useful) to 5 (very useful), respondents reported their attitudes toward the physical examination overall and toward 14 specific physical examination skills. The survey response rate was 117/164 (71%). Students at the Dominican school, compared to students at the U.S. school, reported significantly greater confidence in their overall physical examination skill (mean response 4.27 vs. 3.79, respectively, p < .001) and more positive views about the utility of the physical examination overall for providing diagnostically useful information (mean response 4.78 vs. 4.42, respectively, p < .001). Results for the specific skills also showed more positive attitudes in the students from the Dominican medical school. Students at a Dominican medical school reported more positive attitudes toward the physical examination than students at a U.S. medical school.

Factors associated with reporting results for pulmonary clinical trials in ClinicalTrials.gov.

PubMed

Riley, Isaretta L; Boulware, L Ebony; Sun, Jie-Lena; Chiswell, Karen; Que, Loretta G; Kraft, Monica; Todd, Jamie L; Palmer, Scott M; Anderson, Monique L

2018-02-01

Background/aims The Food and Drug Administration Amendments Act mandates that applicable clinical trials report basic summary results to the ClinicalTrials.gov database within 1 year of trial completion or termination. We aimed to determine the proportion of pulmonary trials reporting basic summary results to ClinicalTrials.gov and assess factors associated with reporting. Methods We identified pulmonary clinical trials subject to the Food and Drug Administration Amendments Act (called highly likely applicable clinical trials) that were completed or terminated between 2008 and 2012 and reported results by September 2013. We estimated the cumulative percentage of applicable clinical trials reporting results by pulmonary disease category. Multivariable Cox regression modeling identified characteristics independently associated with results reporting. Results Of 1450 pulmonary highly likely applicable clinical trials, 380 (26%) examined respiratory neoplasms, 238 (16%) asthma, 175 (12%) chronic obstructive pulmonary disease, and 657 (45%) other respiratory diseases. Most (75%) were pharmaceutical highly likely applicable clinical trials and 71% were industry-funded. Approximately 15% of highly likely applicable clinical trials reported results within 1 year of trial completion, while 55% reported results over the 5-year study period. Earlier phase highly likely applicable clinical trials were less likely to report results compared to phase 4 highly likely applicable clinical trials (phases 1/2 and 2 (adjusted hazard ratio 0.41 (95% confidence interval: 0.31-0.54)), phases 2/3 and 3 (adjusted hazard ratio 0.55 (95% confidence interval: 0.42-0.72)) and phase not applicable (adjusted hazard ratio 0.43 (95% confidence interval: 0.29-0.63)). Pulmonary highly likely applicable clinical trials without Food and Drug Administration oversight were less likely to report results compared with those with oversight (adjusted hazard ratio 0.65 (95% confidence interval: 0.51-0.83)). Conclusion A total of 15% of pulmonary clinical highly likely applicable clinical trials report basic summary results to ClinicalTrials.gov within 1 year of trial completion. Strategies to improve reporting are needed within the pulmonary community.

21 CFR 1002.1 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-04-01

... (1050.10) X X X X X X Diagnostic ultrasound X Medical ultrasound other than therapy or diagnostic X X Nonmedical ultrasound X 1However, authority to inspect all appropriate documents supporting the adequacy of a...

21 CFR 1002.1 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-04-01

... (1050.10) X X X X X X Diagnostic ultrasound X Medical ultrasound other than therapy or diagnostic X X Nonmedical ultrasound X 1However, authority to inspect all appropriate documents supporting the adequacy of a...

21 CFR 1002.1 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-04-01

... (1050.10) X X X X X X Diagnostic ultrasound X Medical ultrasound other than therapy or diagnostic X X Nonmedical ultrasound X 1However, authority to inspect all appropriate documents supporting the adequacy of a...

21 CFR 1002.1 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-04-01

... (1050.10) X X X X X X Diagnostic ultrasound X Medical ultrasound other than therapy or diagnostic X X Nonmedical ultrasound X 1However, authority to inspect all appropriate documents supporting the adequacy of a...

21 CFR 1002.1 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-04-01

... (1050.10) X X X X X X Diagnostic ultrasound X Medical ultrasound other than therapy or diagnostic X X Nonmedical ultrasound X 1However, authority to inspect all appropriate documents supporting the adequacy of a...

Exploring virtual reality technology and the Oculus Rift for the examination of digital pathology slides

PubMed Central

Farahani, Navid; Post, Robert; Duboy, Jon; Ahmed, Ishtiaque; Kolowitz, Brian J.; Krinchai, Teppituk; Monaco, Sara E.; Fine, Jeffrey L.; Hartman, Douglas J.; Pantanowitz, Liron

2016-01-01

Background: Digital slides obtained from whole slide imaging (WSI) platforms are typically viewed in two dimensions using desktop personal computer monitors or more recently on mobile devices. To the best of our knowledge, we are not aware of any studies viewing digital pathology slides in a virtual reality (VR) environment. VR technology enables users to be artificially immersed in and interact with a computer-simulated world. Oculus Rift is among the world's first consumer-targeted VR headsets, intended primarily for enhanced gaming. Our aim was to explore the use of the Oculus Rift for examining digital pathology slides in a VR environment. Methods: An Oculus Rift Development Kit 2 (DK2) was connected to a 64-bit computer running Virtual Desktop software. Glass slides from twenty randomly selected lymph node cases (ten with benign and ten malignant diagnoses) were digitized using a WSI scanner. Three pathologists reviewed these digital slides on a 27-inch 5K display and with the Oculus Rift after a 2-week washout period. Recorded endpoints included concordance of final diagnoses and time required to examine slides. The pathologists also rated their ease of navigation, image quality, and diagnostic confidence for both modalities. Results: There was 90% diagnostic concordance when reviewing WSI using a 5K display and Oculus Rift. The time required to examine digital pathology slides on the 5K display averaged 39 s (range 10–120 s), compared to 62 s with the Oculus Rift (range 15–270 s). All pathologists confirmed that digital pathology slides were easily viewable in a VR environment. The ratings for image quality and diagnostic confidence were higher when using the 5K display. Conclusion: Using the Oculus Rift DK2 to view and navigate pathology whole slide images in a virtual environment is feasible for diagnostic purposes. However, image resolution using the Oculus Rift device was limited. Interactive VR technologies such as the Oculus Rift are novel tools that may be of use in digital pathology. PMID:27217972

Feasibility of ferumoxytol-enhanced neonatal and young infant cardiac MRI without general anesthesia.

PubMed

Lai, Lillian M; Cheng, Joseph Y; Alley, Marcus T; Zhang, Tao; Lustig, Michael; Vasanawala, Shreyas S

2017-05-01

To assess the feasibility of ferumoxytol-enhanced anesthesia-free cardiac MRI in neonates and young infants for complex congenital heart disease (CHD). With Institutional Review Board approval, 21 consecutive neonates and young infants (1 day to 11 weeks old; median age of 3 days) who underwent a rapid two-sequence (MR angiography [MRA] and four-dimensional [4D] flow) MRI protocol with intravenous ferumoxytol without sedation (n = 17) or light sedation (n = 4) at 3 Tesla (T) (except one case at 1.5T) between June 2014 and February 2016 were retrospectively identified. Medical records were reviewed for indication, any complications, if further diagnostic imaging was performed after MRI, and surgical findings. Two radiologists scored the images in two sessions on a 5-point scale for overall image quality and delineation of various anatomical structures. Confidence interval of proportions for likelihood of requiring additional diagnostic imaging after MRI was determined. For the possibility of reducing the protocol to a single rapid sequence, Wilcoxon-rank sum test was used to assess whether 4D flow and MRA significantly differed in anatomical delineation. One of 21 patients (4.8%, 80% confidence interval 0-11%) required additional imaging, a computed tomography angiography to assess lung parenchyma and peripheral pulmonary arteries. Only 1 of 13 patients (7.7%) with operative confirmation had a minor discrepancy between radiology and operative reports (80% confidence interval 0-17%). 4D flow was significantly superior to MRA (P < 0.05) for the evaluation of systemic arteries, valves, ventricular trabeculae, and overall quality. Using Cohen's kappa coefficient, there was good interobserver agreement for the evaluation of systemic arteries by 4D flow (κ = 0.782), and systemic veins and pulmonary arteries by MRA (κ > 0.6). Overall 4D flow measurements (mean κ = 0.64-0.74) had better internal agreement compared with MRA (mean κ = 0.30-0.64). Ferumoxytol-enhanced cardiac MRI, without anesthesia, is feasible for the evaluation of complex CHD in neonates and young infants, with a low likelihood of need for additional diagnostic studies. The decreased risk by avoiding anesthesia must be balanced against the potential for adverse reactions with ferumoxytol. 2 J. MAGN. RESON. IMAGING 2017;45:1407-1418. © 2016 International Society for Magnetic Resonance in Medicine.

Proceedings of Workshop on Laser Diagnostics in Fluid Mechanics and Combustion

NASA Astrophysics Data System (ADS)

1993-10-01

Proceedings of the Workshop on Laser Diagnostics in Fluid Mechanics and Combustion are presented. Topics included are: Accuracy of Laser Doppler Anemometry; Applications of Raman-Rayleigh-LIF Diagnostics in Combustion Research; Phase Doppler Anemometer Technique Concepts and Applications; CARS; Particle Image Velocimetry; Practical Consideration in the Use and Design of Laser Velocimetry Systems in Turbomachinery Applications; Phase Doppler Measurements of Gas-Particle Flow Through a Tube Bank; Degenerate Four Wave Mixing for Shock Tunnel Studies of Supersonic Combustion; Laser Induced Photodissociation and Fluorescence (LIPF) of Sodium Species Present in Coal Combustion; 3D Holographic Measurements Inside a Spark Ignition Engine; Laser Doppler Velocimeter Measurements in Compressible Flow; Bursting in a Tornado Vortex; Quantitative Imaging of OH and Temperature Using a Single Laser Source and Single Intensified Camera; and Laser Doppler Measurements Inside an Artificial Heart Valve.

Multiplexed lateral flow biosensors: Technological advances for radically improving point-of-care diagnoses.

PubMed

Li, Jia; Macdonald, Joanne

2016-09-15

Lateral flow biosensors are a leading technology in point-of-care diagnostics due to their simplicity, rapidness and low cost. Their primacy in this arena continues through technological breakthroughs such as multiplexing: the detection of more than one biomarker in a single assay. Multiplexing capacity is critical for improving diagnostic efficiency, enhancing the diagnostic precision for specific diseases and reducing diagnostic cost. Here we review, for the first time, the various types and strategies employed for creating multiplexed lateral flow biosensors. These are classified into four main categories in terms of specific application or multiplexing level, namely linear, parameter, spatial and conceptual. We describe the practical applications and implications for each approach and compare their advantages and disadvantages. Importantly, multiplexing is still subject to limitations of the traditional lateral flow biosensor, such as sensitivity and specificity. However, by pushing the limitations of the traditional medium into the multiplex arena, several technological breakthroughs are emerging with novel solutions that further expand the utility of lateral flow biosensing for point-of-care applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Advanced DNA-Based Point-of-Care Diagnostic Methods for Plant Diseases Detection.

PubMed

Lau, Han Yih; Botella, Jose R

2017-01-01

Diagnostic technologies for the detection of plant pathogens with point-of-care capability and high multiplexing ability are an essential tool in the fight to reduce the large agricultural production losses caused by plant diseases. The main desirable characteristics for such diagnostic assays are high specificity, sensitivity, reproducibility, quickness, cost efficiency and high-throughput multiplex detection capability. This article describes and discusses various DNA-based point-of care diagnostic methods for applications in plant disease detection. Polymerase chain reaction (PCR) is the most common DNA amplification technology used for detecting various plant and animal pathogens. However, subsequent to PCR based assays, several types of nucleic acid amplification technologies have been developed to achieve higher sensitivity, rapid detection as well as suitable for field applications such as loop-mediated isothermal amplification, helicase-dependent amplification, rolling circle amplification, recombinase polymerase amplification, and molecular inversion probe. The principle behind these technologies has been thoroughly discussed in several review papers; herein we emphasize the application of these technologies to detect plant pathogens by outlining the advantages and disadvantages of each technology in detail.

Advanced DNA-Based Point-of-Care Diagnostic Methods for Plant Diseases Detection

PubMed Central

Lau, Han Yih; Botella, Jose R.

2017-01-01

Diagnostic technologies for the detection of plant pathogens with point-of-care capability and high multiplexing ability are an essential tool in the fight to reduce the large agricultural production losses caused by plant diseases. The main desirable characteristics for such diagnostic assays are high specificity, sensitivity, reproducibility, quickness, cost efficiency and high-throughput multiplex detection capability. This article describes and discusses various DNA-based point-of care diagnostic methods for applications in plant disease detection. Polymerase chain reaction (PCR) is the most common DNA amplification technology used for detecting various plant and animal pathogens. However, subsequent to PCR based assays, several types of nucleic acid amplification technologies have been developed to achieve higher sensitivity, rapid detection as well as suitable for field applications such as loop-mediated isothermal amplification, helicase-dependent amplification, rolling circle amplification, recombinase polymerase amplification, and molecular inversion probe. The principle behind these technologies has been thoroughly discussed in several review papers; herein we emphasize the application of these technologies to detect plant pathogens by outlining the advantages and disadvantages of each technology in detail. PMID:29375588

Computer Assisted Thermography And Its Application In Ovulation Detection

NASA Astrophysics Data System (ADS)

Rao, K. H.; Shah, A. V.

1984-08-01

Hardware and software of a computer-assisted image analyzing system used for infrared images in medical applications are discussed. The application of computer-assisted thermography (CAT) as a complementary diagnostic tool in centralized diagnostic management is proposed. The authors adopted 'Computer Assisted Thermography' to study physiological changes in the breasts related to the hormones characterizing the menstrual cycle of a woman. Based on clinical experi-ments followed by thermal image analysis, they suggest that 'differential skin temperature (DST)1 be measured to detect the fertility interval in the menstrual cycle of a woman.

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

From DSM-IV to DSM-5 alcohol use disorder: an overview of epidemiological data.

PubMed

Bartoli, Francesco; Carrà, Giuseppe; Crocamo, Cristina; Clerici, Massimo

2015-02-01

The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) has made several changes to criteria for alcohol use disorder (AUD). The objective of this systematic review is to assess if new DSM-5 diagnostic criteria will increase the prevalence rates of AUD in clinical and non-clinical samples as compared with DSM-IV criteria. We searched PubMed, Scopus, and PsycINFO (via ProQuest) electronic databases, with no language restrictions. We included studies with data available on both DSM-IV (and DSM-IV-TR) and DSM-5 AUD in samples of adults, estimating from each study an expected increase in prevalence rates with relevant 95% confidence intervals (CIs). Twelve studies were included in this review. Seven studies showed an increase, two no substantial difference, and three a decrease in AUD prevalence according to DSM-5 diagnostic criteria, with differences in rates (95% CIs) varying between -12.4% (-27.4 to +5.6%) and +61.3% (+46.7 to +77.3%). Additional analyses provided confirmatory results. DSM-5 diagnostic criteria seem to inflate prevalence rates of AUD as compared with DSM-IV. The increasing likelihood of a DSM-5 AUD diagnosis may be explained by the amount of DSM-IV 'diagnostic orphans' which are more prevalent than DSM-IV single-criterion alcohol abuse individuals. Further research should be aimed to study if similar trends are detectable also for other substance use disorders that experienced similar changes in DSM-5 diagnostic criteria. Copyright © 2014 Elsevier Ltd. All rights reserved.

An exploratory study demonstrating the diagnostic ability of healthcare professionals in primary care using online case studies for common skin conditions.

PubMed

Tucker, Rod; Patel, Mahendra; Layton, Alison L; Walton, Shernaz

2014-04-01

To compare the diagnostic ability of pharmacists, nurses and general practitioners (GPs) for a range of skin conditions. An online study comprising 10 specifically developed dermatological case studies containing a digital image of the skin condition and a short case history. A total of 60 participants (20 representing each of pharmacists, GPs and primary care nurses) were required to identify the skin condition as well as the features in the case history that supported the diagnosis and the recommended first-line management approach for the condition. The mean diagnostic scores for each group were GPs = 8.8 (95% confidence interval, CI, 7.9-9.6), pharmacists = 6.2 (95% CI, 5.4-6.9) and nurses = 7.0 (95% CI, 6.1-7.9). Post hoc analysis revealed that the difference in mean diagnostic scores was significant (P < 0.05) between GPs and both pharmacists and nurses. However, pharmacists' diagnostic accuracy was similar to GPs' for some skin conditions such as tinea corporis, scabies and plantar warts and overall at least 40% of pharmacists correctly identified all conditions. This small study has demonstrated that for all of the skin conditions considered, pharmacists' overall diagnostic scores were significantly different from those of GPs but similar to those of nurses for the conditions assessed. However, further work with a larger sample is required to determine the accuracy of these preliminary findings and to establish whether advice given by pharmacists in practice results in the appropriate course of action being taken. © 2013 Royal Pharmaceutical Society.

Comparison of tissue equalization, and premium view post-processing methods in full field digital mammography.

PubMed

Chen, Baoying; Wang, Wei; Huang, Jin; Zhao, Ming; Cui, Guangbin; Xu, Jing; Guo, Wei; Du, Pang; Li, Pei; Yu, Jun

2010-10-01

To retrospectively evaluate the diagnostic abilities of 2 post-processing methods provided by GE Senographe DS system, tissue equalization (TE) and premium view (PV) in full field digital mammography (FFDM). In accordance with the ethical standards of the World Medical Association, this study was approved by regional ethics committee and signed informed patient consents were obtained. We retrospectively reviewed digital mammograms from 101 women (mean age, 47 years; range, 23-81 years) in the modes of TE and PV, respectively. Three radiologists, fully blinded to the post-processing methods, all patient clinical information and histologic results, read images by using objective image interpretation criteria for diagnostic information end points such as lesion border delineation, definition of disease extent, visualization of internal and surrounding morphologic features of the lesions. Also, overall diagnostic impression in terms of lesion conspicuity, detectability and diagnostic confidence was assessed. Between-group comparisons were performed with Wilcoxon signed rank test. Readers 1, 2, and 3 demonstrated significant overall better impression of PV in 29, 27, and 24 patients, compared with that for TE in 12, 13, and 11 patients, respectively (p<0.05). Significant (p<0.05) better impression of PV was also demonstrated for diagnostic information end points. Importantly, PV proved to be more sensitive than TE while detecting malignant lesions in dense breast rather than benign lesions and malignancy in non-dense breast (p<0.01). PV compared with TE provides marked better diagnostic information in FFDM, particularly for patients with malignancy in dense breast. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Diagnostic Tests to Support Late-Stage Control Programs for Schistosomiasis and Soil-Transmitted Helminthiases.

PubMed

Hawkins, Kenneth R; Cantera, Jason L; Storey, Helen L; Leader, Brandon T; de Los Santos, Tala

2016-12-01

Global efforts to address schistosomiasis and soil-transmitted helminthiases (STH) include deworming programs for school-aged children that are made possible by large-scale drug donations. Decisions on these mass drug administration (MDA) programs currently rely on microscopic examination of clinical specimens to determine the presence of parasite eggs. However, microscopy-based methods are not sensitive to the low-intensity infections that characterize populations that have undergone MDA. Thus, there has been increasing recognition within the schistosomiasis and STH communities of the need for improved diagnostic tools to support late-stage control program decisions, such as when to stop or reduce MDA. Failure to adequately address the need for new diagnostics could jeopardize achievement of the 2020 London Declaration goals. In this report, we assess diagnostic needs and landscape potential solutions and determine appropriate strategies to improve diagnostic testing to support control and elimination programs. Based upon literature reviews and previous input from experts in the schistosomiasis and STH communities, we prioritized two diagnostic use cases for further exploration: to inform MDA-stopping decisions and post-MDA surveillance. To this end, PATH has refined target product profiles (TPPs) for schistosomiasis and STH diagnostics that are applicable to these use cases. We evaluated the limitations of current diagnostic methods with regards to these use cases and identified candidate biomarkers and diagnostics with potential application as new tools. Based on this analysis, there is a need to develop antigen-detecting rapid diagnostic tests (RDTs) with simplified, field-deployable sample preparation for schistosomiasis. Additionally, there is a need for diagnostic tests that are more sensitive than the current methods for STH, which may include either a field-deployable molecular test or a simple, low-cost, rapid antigen-detecting test.

The Modified Femoral Neck-Shaft Angle: Age- and Sex-Dependent Reference Values and Reliability Analysis

PubMed Central

Jostmeier, Janine; Haneder, Stefan; Dargel, Jens; Eysel, Peer; Lechler, Philipp

2016-01-01

Background. The femoral neck-shaft angle (NSA) is of high importance for the diagnostics and treatment of various conditions of the hip. However, rotational effects limit its precision and applicability using plain radiographs. This study introduces a novel method to measure the femoral NSA: the modified NSA (mNSA), possibly being less susceptible against rotational effects compared to the conventional NSA. Patients and Methods. The method of measurement is described and its applicability was tested in 400 pelvis computed tomography scans (800 hips). Age- and gender-dependent reference values are given and intra- and interrater reliability are analyzed. Results. The mean age of all 400 patients (800 hips) was 54.32 years (18–100, SD 22.05 years). The mean mNSA was 147.0° and the 95% confidence interval was 146.7°–147.4°. Differences of the mNSA between sexes, age groups, and sides were nonsignificant. The absolute difference between NSA and mNSA was 16.3° (range 3–31°; SD 4.4°); the correlation was high (0.738; p < 0.001). Overall, the intra- and interrater reliability were excellent for the mNSA. Interpretation. We introduced a novel concept for the analysis of the neck-shaft angle. The high reliability of the measurement has been proven and its robustness to hip rotation was demonstrated. PMID:28070521

The Modified Femoral Neck-Shaft Angle: Age- and Sex-Dependent Reference Values and Reliability Analysis.

PubMed

Boese, Christoph Kolja; Frink, Michael; Jostmeier, Janine; Haneder, Stefan; Dargel, Jens; Eysel, Peer; Lechler, Philipp

2016-01-01

Background . The femoral neck-shaft angle (NSA) is of high importance for the diagnostics and treatment of various conditions of the hip. However, rotational effects limit its precision and applicability using plain radiographs. This study introduces a novel method to measure the femoral NSA: the modified NSA (mNSA), possibly being less susceptible against rotational effects compared to the conventional NSA. Patients and Methods . The method of measurement is described and its applicability was tested in 400 pelvis computed tomography scans (800 hips). Age- and gender-dependent reference values are given and intra- and interrater reliability are analyzed. Results . The mean age of all 400 patients (800 hips) was 54.32 years (18-100, SD 22.05 years). The mean mNSA was 147.0° and the 95% confidence interval was 146.7°-147.4°. Differences of the mNSA between sexes, age groups, and sides were nonsignificant. The absolute difference between NSA and mNSA was 16.3° (range 3-31°; SD 4.4°); the correlation was high (0.738; p < 0.001). Overall, the intra- and interrater reliability were excellent for the mNSA. Interpretation . We introduced a novel concept for the analysis of the neck-shaft angle. The high reliability of the measurement has been proven and its robustness to hip rotation was demonstrated.

Fluorescence lifetime endoscopy using TCSPC for the measurement of FRET in live cells

PubMed Central

Fruhwirth, Gilbert O.; Ameer-Beg, Simon; Cook, Richard; Watson, Timothy; Ng, Tony; Festy, Frederic

2010-01-01

Development of remote imaging for diagnostic purposes has progressed dramatically since endoscopy began in the 1960’s. The recent advent of a clinically licensed intensity-based fluorescence micro-endoscopic instrument has offered the prospect of real-time cellular resolution imaging. However, interrogating protein-protein interactions deep inside living tissue requires precise fluorescence lifetime measurements to derive the Förster resonance energy transfer between two tagged fluorescent markers. We developed a new instrument combining remote fiber endoscopic cellular-resolution imaging with TCSPC-FLIM technology to interrogate and discriminate mixed fluorochrome labeled beads and expressible GFP/TagRFP tags within live cells. Endoscopic-FLIM (e-FLIM) data was validated by comparison with data acquired via conventional FLIM and e-FLIM was found to be accurate for both bright bead and dim live cell samples. The fiber based micro-endoscope allowed remote imaging of 4 µm and 10 µm beads within a thick Matrigel matrix with confident fluorophore discrimination using lifetime information. More importantly, this new technique enabled us to reliably measure protein-protein interactions in live cells embedded in a 3D matrix, as demonstrated by the dimerization of the fluorescent protein-tagged membrane receptor CXCR4. This cell-based application successfully demonstrated the suitability and great potential of this new technique for in vivo pre-clinical biomedical and possibly human clinical applications. PMID:20588974

Engineered Biocompatible Nanoparticles for in Vivo Imaging Applications

PubMed Central

2010-01-01

Iron−platinum alloy nanoparticles (FePt NPs) are extremely promising candidates for the next generation of contrast agents for magnetic resonance (MR) diagnostic imaging and MR-guided interventions, including hyperthermic ablation of solid cancers. FePt has high Curie temperature, saturation magnetic moment, magneto-crystalline anisotropy, and chemical stability. We describe the synthesis and characterization of a family of biocompatible FePt NPs suitable for biomedical applications, showing and discussing that FePt NPs can exhibit low cytotoxicity. The importance of engineering the interface of strongly magnetic NPs using a coating allowing free aqueous permeation is demonstrated to be an essential parameter in the design of new generations of diagnostic and therapeutic MRI contrast agents. We report effective cell internalization of FePt NPs and demonstrate that they can be used for cellular imaging and in vivo MRI applications. This opens the way for several future applications of FePt NPs, including regenerative medicine and stem cell therapy in addition to enhanced MR diagnostic imaging. PMID:20919679

Load estimator (LOADEST): a FORTRAN program for estimating constituent loads in streams and rivers

USGS Publications Warehouse

Runkel, Robert L.; Crawford, Charles G.; Cohn, Timothy A.

2004-01-01

LOAD ESTimator (LOADEST) is a FORTRAN program for estimating constituent loads in streams and rivers. Given a time series of streamflow, additional data variables, and constituent concentration, LOADEST assists the user in developing a regression model for the estimation of constituent load (calibration). Explanatory variables within the regression model include various functions of streamflow, decimal time, and additional user-specified data variables. The formulated regression model then is used to estimate loads over a user-specified time interval (estimation). Mean load estimates, standard errors, and 95 percent confidence intervals are developed on a monthly and(or) seasonal basis. The calibration and estimation procedures within LOADEST are based on three statistical estimation methods. The first two methods, Adjusted Maximum Likelihood Estimation (AMLE) and Maximum Likelihood Estimation (MLE), are appropriate when the calibration model errors (residuals) are normally distributed. Of the two, AMLE is the method of choice when the calibration data set (time series of streamflow, additional data variables, and concentration) contains censored data. The third method, Least Absolute Deviation (LAD), is an alternative to maximum likelihood estimation when the residuals are not normally distributed. LOADEST output includes diagnostic tests and warnings to assist the user in determining the appropriate estimation method and in interpreting the estimated loads. This report describes the development and application of LOADEST. Sections of the report describe estimation theory, input/output specifications, sample applications, and installation instructions.

Development and Application of Diagnostics in the National Schistosomiasis Control Programme in The People's Republic of China.

PubMed

Zhang, J-F; Xu, J; Bergquist, R; Yu, L-L; Yan, X-L; Zhu, H-Q; Wen, L-Y

2016-01-01

Schistosomiasis, caused by Schistosoma japonicum infection to human, has a documented history of more than 2100years in The People's Republic of China. In spite of great progress in controlling the disease, it is still one of the most serious parasitic diseases in the country. The study and use of diagnostic techniques play an important role in the targeting of chemotherapy that has been continuously applied in the national schistosomiasis control programme for several decades. This paper reviews the development and application of parasitological, immunodiagnostic and molecular diagnostic technology for S. japonicum in The People's Republic of China with a brief mention of diagnostic imagery, such as ultrasound and radiology. When analysing the efficacy and performance characteristics of the main diagnostic techniques in current use, it becomes apparent that approaches that worked well in the past are less suitable now as successful control has shifted the endemic situation towards control and interruption of transmission. The conclusion is that a mutable approach must be adopted choosing the most appropriate diagnostic technique for each control stage (and area), thus modifying the methodology according to the prevailing diagnostic needs in terms of sensitivity and specificity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Applications of FT-IR spectrophotometry in cancer diagnostics.

PubMed

Bunaciu, Andrei A; Hoang, Vu Dang; Aboul-Enein, Hassan Y

2015-01-01

This review provides a brief background to the application of infrared spectroscopy, including Fourier transform-infrared spectroscopy, in biological fluids. It is not meant to be complete or exhaustive but to provide the reader with sufficient background for selected applications in cancer diagnostics. Fourier transform-infrared spectroscopy (FT-IR) is a fast and nondestructive analytical method. The infrared spectrum of a mixture serves as the basis to quantitate its constituents, and a number of common clinical chemistry tests have proven to be feasible using this approach. This review focuses on biomedical FT-IR applications, published in the period 2009-2013, used for early detection of cancer through qualitative and quantitative analysis.

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.

Applications of Laser Diagnostics

DTIC Science & Technology

2005-03-01

Heat Transfer and Thermal Management of PDE . . . . 39 5.1.2 Application of Optical and Numerical Diagnostic Methods to PDE...in Reno, NV. The paper is included in the Appendix. 5.1.1.16 Heat Transfer and Thermal Management in PDE The unsteady nature of the PDE cycle...January 2003, Reno, NV. 57 “Heat Transfer and Thermal Management in a Pulsed Detonation Engine,” J. Hoke, R. Bradley, and F. Schauer, AIAA Paper No

Polymeric nanoparticles for optical sensing.

PubMed

Canfarotta, Francesco; Whitcombe, Michael J; Piletsky, Sergey A

2013-12-01

Nanotechnology is a powerful tool for use in diagnostic applications. For these purposes a variety of functional nanoparticles containing fluorescent labels, gold and quantum dots at their cores have been produced, with the aim of enhanced sensitivity and multiplexing capabilities. This work will review progress in the application of polymeric nanoparticles in optical diagnostics, both for in vitro and in vivo detection, together with a discussion of their biodistribution and biocompatibility. © 2013.

Non-invasive biomedical research and diagnostics enabled by innovative compact lasers

NASA Astrophysics Data System (ADS)

Litvinova, Karina S.; Rafailov, Ilya E.; Dunaev, Andrey V.; Sokolovski, Sergei G.; Rafailov, Edik U.

2017-11-01

For over half a century, laser technology has undergone a technological revolution. These technologies, particularly semiconductor lasers, are employed in a myriad of fields. Optical medical diagnostics, one of the emerging areas of laser application, are on the forefront of application around the world. Optical methods of non- or minimally invasive bio-tissue investigation offer significant advantages over alternative methods, including rapid real-time measurement, non-invasiveness and high resolution (guaranteeing the safety of a patient). These advantages demonstrate the growing success of such techniques. In this review, we will outline the recent status of laser technology applied in the biomedical field, focusing on the various available approaches, particularly utilising compact semiconductor lasers. We will further consider the advancement and integration of several complimentary biophotonic techniques into single multimodal devices, the potential impact of such devices and their future applications. Based on our own studies, we will also cover the simultaneous collection of physiological data with the aid a multifunctional diagnostics system, concentrating on the optimisation of the new technology towards a clinical application. Such data is invaluable for developing algorithms capable of delivering consistent, reliable and meaningful diagnostic information, which can ultimately be employed for the early diagnosis of disease conditions in individuals from around the world.

A biocatalytic cascade with several output signals—towards biosensors with different levels of confidence

PubMed Central

Guz, Nataliia; Halámek, Jan; Rusling, James F.; Katz, Evgeny

2014-01-01

The biocatalytic cascade based on enzyme-catalyzed reactions activated by several biomolecular input signals and producing output signal after each reaction step was developed as an example of a logically reversible information processing system. The model system was designed to mimic the operation of concatenated AND logic gates with optically readable output signals generated at each step of the logic operation. Implications include concurrent bioanalyses and data interpretation for medical diagnostics. PMID:24748446

Acoustic analysis of swallowing sounds: a new technique for assessing dysphagia.

PubMed

Santamato, Andrea; Panza, Francesco; Solfrizzi, Vincenzo; Russo, Anna; Frisardi, Vincenza; Megna, Marisa; Ranieri, Maurizio; Fiore, Pietro

2009-07-01

To perform acoustic analysis of swallowing sounds, using a microphone and a notebook computer system, in healthy subjects and patients with dysphagia affected by neurological diseases, testing the positive/negative predictive value of a pathological pattern of swallowing sounds for penetration/aspiration. Diagnostic test study, prospective, not blinded, with the penetration/aspiration evaluated by fibreoptic endoscopy of swallowing as criterion standard. Data from a previously recorded database of normal swallowing sounds for 60 healthy subjects according to gender, age, and bolus consistency was compared with those of 15 patients with dysphagia from a university hospital referral centre who were affected by various neurological diseases. Mean duration of the swallowing sounds and post-swallowing apnoea were recorded. Penetration/aspiration was verified by fibreoptic endoscopy of swallowing in all patients with dysphagia. The mean duration of swallowing sounds for a liquid bolus of 10 ml water was significantly different between patients with dysphagia and healthy patients. We also described patterns of swallowing sounds and tested the negative/positive predictive values of post-swallowing apnoea for penetration/aspiration verified by fibreoptic endoscopy of swallowing (sensitivity 0.67 (95% confidence interval 0.24-0.94); specificity 1.00 (95% confidence interval 0.56-1.00)). The proposed technique for recording and measuring swallowing sounds could be incorporated into the bedside evaluation, but it should not replace the use of more diagnostic and valuable measures.

A diagnostic expert system for aircraft generator control unit (GCU)

NASA Astrophysics Data System (ADS)

Ho, Ting-Long; Bayles, Robert A.; Havlicsek, Bruce L.

The modular VSCF (variable-speed constant-frequency) generator families are described as using standard modules to reduce the maintenance cost and to improve the product's testability. A general diagnostic expert system shell that guides troubleshooting of modules or line replaceable units (LRUs) is introduced. An application of the diagnostic system to a particular LRU, the generator control unit (GCU) is reported. The approach to building the diagnostic expert system is first to capture general diagnostic strategy in an expert system shell. This shell can be easily applied to different devices or LRUs by writing rules to capture only additional device-specific diagnostic information from expert repair personnel. The diagnostic system has the necessary knowledge embedded in its programs and exhibits expertise to troubleshoot the GCU.

Clinical reasoning in the real world is mediated by bounded rationality: implications for diagnostic clinical practice guidelines.

PubMed

Bonilauri Ferreira, Ana Paula Ribeiro; Ferreira, Rodrigo Fernando; Rajgor, Dimple; Shah, Jatin; Menezes, Andrea; Pietrobon, Ricardo

2010-04-20

Little is known about the reasoning mechanisms used by physicians in decision-making and how this compares to diagnostic clinical practice guidelines. We explored the clinical reasoning process in a real life environment. This is a qualitative study evaluating transcriptions of sixteen physicians' reasoning during appointments with patients, clinical discussions between specialists, and personal interviews with physicians affiliated to a hospital in Brazil. FOUR MAIN THEMES WERE IDENTIFIED: simple and robust heuristics, extensive use of social environment rationality, attempts to prove diagnostic and therapeutic hypothesis while refuting potential contradictions using positive test strategy, and reaching the saturation point. Physicians constantly attempted to prove their initial hypothesis while trying to refute any contradictions. While social environment rationality was the main factor in the determination of all steps of the clinical reasoning process, factors such as referral letters and number of contradictions associated with the initial hypothesis had influence on physicians' confidence and determination of the threshold to reach a final decision. Physicians rely on simple heuristics associated with environmental factors. This model allows for robustness, simplicity, and cognitive energy saving. Since this model does not fit into current diagnostic clinical practice guidelines, we make some propositions to help its integration.

Assessing the effectiveness of problem-based learning in physical diagnostics education in China: a meta-analysis

PubMed Central

Wang, Jianmiao; Xu, Yongjian; Liu, Xiansheng; Xiong, Weining; Xie, Jungang; Zhao, Jianping

2016-01-01

Problem-based learning (PBL) has been extensively applied as an experimental educational method in Chinese medical schools over the past decade. A meta-analysis was performed to assess the effectiveness of PBL on students’ learning outcomes in physical diagnostics education. Related databases were searched for eligible studies evaluating the effects of PBL compared to traditional teaching on students’ knowledge and/or skill scores of physical diagnostics. Standardized mean difference (SMD) with 95% confidence interval (CI) was estimated. Thirteen studies with a total of 2086 medical students were included in this meta-analysis. All of these studies provided usable data on knowledge scores, and the pooled analysis showed a significant difference in favor of PBL compared to the traditional teaching (SMD = 0.76, 95%CI = 0.33–1.19). Ten studies provided usable data on skill scores, and a significant difference in favor of PBL was also observed (SMD = 1.46, 95%CI = 0.89–2.02). Statistically similar results were obtained in the sensitivity analysis, and there was no significant evidence of publication bias. These results suggested that PBL in physical diagnostics education in China appeared to be more effective than traditional teaching method in improving knowledge and skills. PMID:27808158

Assessing the effectiveness of problem-based learning in physical diagnostics education in China: a meta-analysis.

PubMed

Wang, Jianmiao; Xu, Yongjian; Liu, Xiansheng; Xiong, Weining; Xie, Jungang; Zhao, Jianping

2016-11-03

Problem-based learning (PBL) has been extensively applied as an experimental educational method in Chinese medical schools over the past decade. A meta-analysis was performed to assess the effectiveness of PBL on students' learning outcomes in physical diagnostics education. Related databases were searched for eligible studies evaluating the effects of PBL compared to traditional teaching on students' knowledge and/or skill scores of physical diagnostics. Standardized mean difference (SMD) with 95% confidence interval (CI) was estimated. Thirteen studies with a total of 2086 medical students were included in this meta-analysis. All of these studies provided usable data on knowledge scores, and the pooled analysis showed a significant difference in favor of PBL compared to the traditional teaching (SMD = 0.76, 95%CI = 0.33-1.19). Ten studies provided usable data on skill scores, and a significant difference in favor of PBL was also observed (SMD = 1.46, 95%CI = 0.89-2.02). Statistically similar results were obtained in the sensitivity analysis, and there was no significant evidence of publication bias. These results suggested that PBL in physical diagnostics education in China appeared to be more effective than traditional teaching method in improving knowledge and skills.

Clinical Reasoning in the Real World Is Mediated by Bounded Rationality: Implications for Diagnostic Clinical Practice Guidelines

PubMed Central

Bonilauri Ferreira, Ana Paula Ribeiro; Ferreira, Rodrigo Fernando; Rajgor, Dimple; Shah, Jatin; Menezes, Andrea; Pietrobon, Ricardo

2010-01-01

Background Little is known about the reasoning mechanisms used by physicians in decision-making and how this compares to diagnostic clinical practice guidelines. We explored the clinical reasoning process in a real life environment. Method This is a qualitative study evaluating transcriptions of sixteen physicians' reasoning during appointments with patients, clinical discussions between specialists, and personal interviews with physicians affiliated to a hospital in Brazil. Results Four main themes were identified: simple and robust heuristics, extensive use of social environment rationality, attempts to prove diagnostic and therapeutic hypothesis while refuting potential contradictions using positive test strategy, and reaching the saturation point. Physicians constantly attempted to prove their initial hypothesis while trying to refute any contradictions. While social environment rationality was the main factor in the determination of all steps of the clinical reasoning process, factors such as referral letters and number of contradictions associated with the initial hypothesis had influence on physicians' confidence and determination of the threshold to reach a final decision. Discussion Physicians rely on simple heuristics associated with environmental factors. This model allows for robustness, simplicity, and cognitive energy saving. Since this model does not fit into current diagnostic clinical practice guidelines, we make some propositions to help its integration. PMID:20421920

How to manage thyroid nodules with two consecutive non-diagnostic results on ultrasonography-guided fine-needle aspiration.

PubMed

Moon, Hee Jung; Kwak, Jin Young; Choi, Yoon Seong; Kim, Eun-Kyung

2012-03-01

The aim of this study was to investigate the factors for considering surgery on thyroid nodules that had non-diagnostic results on two consecutive cytology examinations. A total of 104 thyroid nodules with two consecutive non-diagnostic cytology examinations in 104 patients were investigated. Nodules with one or more suspicious ultrasonography (US) features of marked hypoechogenicity, a not well defined margin, microcalcifications, or a taller-than-wide shape were assessed as sonographically suspicious. Those without any suspicious features were assessed as sonographically benign. The clinicopathologic characteristics of patients and US features of the nodules were compared according to malignancy and benignity. The odds ratio for predicting malignancy was calculated. Altogether, 12 nodules were malignant, and 92 were benign. Age, sex, nodule size, and solidness were not associated with malignancy (P = 0.73, 0.92, 0.48, and 0.73, respectively). The malignancy rate of sonographically suspicious nodules was 25.7%, higher than the 4.3% of sonographically benign nodules (P = 0.002). The odds ratio of sonographically suspicious nodules for predicting malignancy was 16.01 (95% confidence interval 2.36-108.54, P = 0.005). Based on sonographic features, surgery can be performed selectively on nodules with two consecutive non-diagnostic cytology results.

The diagnosis of idiopathic pulmonary fibrosis: current and future approaches

PubMed Central

Martinez, Fernando J; Chisholm, Alison; Collard, Harold R; Flaherty, Kevin R; Myers, Jeffrey; Raghu, Ganesh; Walsh, Simon LF; White, Eric S; Richeldi, Luca

2017-01-01

With the recent development of two effective treatments for patients with idiopathic pulmonary fibrosis, an accurate diagnosis is crucial. The traditional approach to diagnosis emphasises the importance of thorough clinical and laboratory evaluations to exclude secondary causes of disease. High-resolution CT is a critical initial diagnostic test and acts as a tool to identify patients who should undergo surgical lung biopsy to secure a definitive histological diagnosis of usual interstitial pneumonia pattern. This diagnostic approach faces several challenges. Many patients with suspected idiopathic pulmonary fibrosis present with atypical high-resolution CT characteristics but are unfit for surgical lung biopsy, therefore preventing a confident diagnosis. The state of the art suggests an iterative, multidisciplinary process that incorporates available clinical, laboratory, imaging, and histological features. Recent research has explored genomic techniques to molecularly phenotype patients with interstitial lung disease. In the future, clinicians will probably use blood-specific or lung-specific molecular markers in combination with other clinical, physiological, and imaging features to enhance diagnostic efforts, refine prognostic recommendations, and influence the initial or subsequent treatment options. There is an urgent and increasing need for well designed, large, prospective studies measuring the effect of different diagnostic approaches. Ultimately, this will help to inform the development of guidelines and tailor clinical practice for the benefit of patients. PMID:27932290

Prevalence, phenotype and cardiometabolic risk of polycystic ovary syndrome under different diagnostic criteria.

PubMed

Yildiz, Bulent Okan; Bozdag, Gurkan; Yapici, Zuhal; Esinler, Ibrahim; Yarali, Hakan

2012-10-01

What is the prevalence, phenotype and metabolic features of polycystic ovary syndrome (PCOS) in the same population according to three different diagnostic criteria? The prevalence of PCOS under National Institutes of Health (NIH), Rotterdam and Androgen Excess and PCOS (AE-PCOS) Society criteria was 6.1, 19.9 and 15.3%, respectively. PCOS carried a 2-fold increased risk of metabolic syndrome regardless of the diagnostic criteria used. The prevalence rates of PCOS differ depending on the diagnostic criteria used to define the syndrome. The current paper gives the prevalence rates of the component and composite phenotypes of PCOS in the same population and reports similar rates of metabolic syndrome in women with PCOS under contrasting diagnostic criteria. In this cross-sectional study, 392 women between the ages of 18 and 45 years were analyzed. When the prevalence of PCOS according to NIH was set to 8% with a precision of 2.2% and confidence interval of 95%, the sample size required for a prevalence survey was found to be 400 subjects. The study was carried out in the General Directorate of Mineral Research and Exploration, a government-based institute, in which the largest number of female staff (n = 527) are employed within a single institute in Ankara, Turkey. The study was performed between 7 December 2009 and 30 April 2010. All female subjects between the ages of 18 and 45 years were invited to participate. Women older than 45 or younger than 18 years, post-menopausal women, women with a history of hysterectomy or bilateral oopherectomy and pregnant women were excluded. Totally, 392 of the employees were recruited for the final analyses. The prevalence of PCOS under NIH, Rotterdam and AE-PCOS Society criteria were 6.1, 19.9 and 15.3%, respectively. While the prevalence of metabolic syndrome was 6.1% in the whole study group, within the patients diagnosed as PCOS according to NIH, Rotterdam and AE-PCOS Society criteria, it was 12.5, 10.3 and 10.0%, respectively. Even though we have included women working at a single institution with a high response rate for the participation, we cannot exclude potential selection bias due to undetermined differences between our sample and background community. We might have underestimated actual prevalence of metabolic syndrome in PCOS due to lack of oral glucose tolerance test 2 h glucose data. Current results can be generalized to Caucasian populations and may present variations in other populations according to race and ethnicity. This work was, in part, sponsored by Merck Serono. Not applicable.

Effectiveness of Immersive Virtual Reality in Surgical Training-A Randomized Control Trial.

PubMed

Pulijala, Yeshwanth; Ma, Minhua; Pears, Matthew; Peebles, David; Ayoub, Ashraf

2018-05-01

Surgical training methods are evolving with the technological advancements, including the application of virtual reality (VR) and augmented reality. However, 28 to 40% of novice residents are not confident in performing a major surgical procedure. VR surgery, an immersive VR (iVR) experience, was developed using Oculus Rift and Leap Motion devices (Leap Motion, Inc, San Francisco, CA) to address this challenge. Our iVR is a multisensory, holistic surgical training application that demonstrates a maxillofacial surgical technique, the Le Fort I osteotomy. The main objective of the present study was to evaluate the effect of using VR surgery on the self-confidence and knowledge of surgical residents. A multisite, single-blind, parallel, randomized controlled trial (RCT) was performed. The participants were novice surgical residents with limited experience in performing the Le Fort I osteotomy. The primary outcome measures were the self-assessment scores of trainee confidence using a Likert scale and an objective assessment of the cognitive skills. Ninety-five residents from 7 dental schools were included in the RCT. The participants were randomly divided into a study group of 51 residents and a control group of 44. Participants in the study group used the VR surgery application on an Oculus Rift with Leap Motion device. The control group participants used similar content in a standard PowerPoint presentation on a laptop. Repeated measures multivariate analysis of variance was applied to the data to assess the overall effect of the intervention on the confidence of the residents. The study group participants showed significantly greater perceived self-confidence levels compared with those in the control group (P = .034; α = 0.05). Novices in the first year of their training showed the greatest improvement in their confidence compared with those in their second and third year. iVR experiences improve the knowledge and self-confidence of the surgical residents. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Diagnostic quality driven physiological data collection for personal healthcare.

PubMed

Jea, David; Balani, Rahul; Hsu, Ju-Lan; Cho, Dae-Ki; Gerla, Mario; Srivastava, Mani B

2008-01-01

We believe that each individual is unique, and that it is necessary for diagnosis purpose to have a distinctive combination of signals and data features that fits the personal health status. It is essential to develop mechanisms for reducing the amount of data that needs to be transferred (to mitigate the troublesome periodically recharging of a device) while maintaining diagnostic accuracy. Thus, the system should not uniformly compress the collected physiological data, but compress data in a personalized fashion that preserves the 'important' signal features for each individual such that it is enough to make the diagnosis with a required high confidence level. We present a diagnostic quality driven mechanism for remote ECG monitoring, which enables a notation of priorities encoded into the wave segments. The priority is specified by the diagnosis engine or medical experts and is dynamic and individual dependent. The system pre-processes the collected physiological information according to the assigned priority before delivering to the backend server. We demonstrate that the proposed approach provides accurate inference results while effectively compressing the data.

Convergent Validity, Concurrent Validity, and Diagnostic Accuracy of the interRAI Depression Rating Scale.

PubMed

Penny, Katherine; Barron, Alex; Higgins, Ann-Marie; Gee, Susan; Croucher, Matthew; Cheung, Gary

2016-09-19

Depression Rating Scale (DRS) is one of the clinical outcome measures of the International Resident Assessment Instrument (interRAI) assessment. The primary aim of this study is to investigate the diagnostic accuracy and concurrent validity of the 3-day assessment window version of the DRS. The performance of DRS was compared with a gold standard clinical diagnosis of depression in 92 patients (age ≥65) who had interRAI version 9.1 Home Care assessment completed within 30 days of discharge from psychogeriatric inpatient care or memory clinic assessment. The DRS had poor diagnostic accuracy for depression diagnosis with an area under the curve of 0.68 (95% confidence interval [CI] = 0.57-0.77). The DRS score had a poor to moderate correlation with the Health of the Nation Outcome Scale 65+ depression item score (r s = 0.30, 95% CI = 0.09-0.48, P = .006). This study and the existing literature raise concerns that the DRS is not an adequate measure of depression. © The Author(s) 2016.

Computer Applications in Educational Audiology.

ERIC Educational Resources Information Center

Mendel, Lisa Lucks; And Others

1995-01-01

This article provides an overview of how computer technologies can be used by educational audiologists. Computer technologies are classified into three categories: (1) information systems applications; (2) screening and diagnostic applications; and (3) intervention applications. (Author/DB)

Calculation of upper confidence bounds on not-sampled vegetation types using a systematic grid sample: An application to map unit definition for existing vegetation maps

Treesearch

Paul L. Patterson; Mark Finco

2009-01-01

This paper explores the information FIA data can produce regarding forest types that were not sampled and develops the equations necessary to define the upper confidence bounds on not-sampled forest types. The problem is reduced to a Bernoulli variable. This simplification allows the upper confidence bounds to be calculated based on Cochran (1977). Examples are...

Diagnostics in Japan's microgravity experiments

NASA Technical Reports Server (NTRS)

Kadota, Toshikazu

1995-01-01

The achievement of the combustion research under microgravity depends substantially on the availability of diagnostic systems. The non-intrusive diagnostic systems are potentially applicable for providing the accurate, realistic and detailed information on momentum, mass and energy transport, complex gas phase chemistry, and phase change in the combustion field under microgravity. The non-intrusive nature of optical instruments is essential to the measurement of combustion process under microgravity which is very nervous to any perturbation. However, the implementation of the non-intrusive combustion diagnostic systems under microgravity is accompanied by several constraints. Usually, a very limited space is only available for constructing a highly sophisticated system which is so sensitive that it is easily affected by the magnitude of the gravitational force, vibration and heterogeneous field of temperature and density of the environments. The system should be properly adjusted prior to the experiment. Generally, it is quite difficult to tune the instruments during measurements. The programmed sequence of operation should also be provided. Extensive effort has been toward the development of non-intrusive diagnostic systems available for the combustion experiments under microgravity. This paper aims to describe the current art and the future strategy on the non-intrusive diagnostic systems potentially applicable to the combustion experiments under microgravity in Japan.