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Sample records for relative lesion detection

  1. Traditional lesion detection aids.

    PubMed

    Neuhaus, K W; Ellwood, R; Lussi, A; Pitts, N B

    2009-01-01

    Lesion detection aids ideally aim at increasing the sensitivity of visual caries detection without trading off too much in terms of specificity. The use of a dental probe (explorer), bitewing radiography and fibre-optic transillumination (FOTI) have long been recommended for this purpose. Today, probing of suspected lesions in the sense of checking the 'stickiness' is regarded as obsolete, since it achieves no gain of sensitivity and might cause irreversible tooth damage. Bitewing radiography helps to detect lesions that are otherwise hidden from visual examination, and it should therefore be applied to a new patient. The diagnostic performance of radiography at approximal and occlusal sites is different, as this relates to the 3-dimensional anatomy of the tooth at these sites. However, treatment decisions have to take more into account than just lesion extension. Bitewing radiography provides additional information for the decision-making process that mainly relies on the visual and clinical findings. FOTI is a quick and inexpensive method which can enhance visual examination of all tooth surfaces. Both radiography and FOTI can improve the sensitivity of caries detection, but require sufficient training and experience to interpret information correctly. Radiography also carries the burden of the risks and legislation associated with using ionizing radiation in a health setting and should be repeated at intervals guided by the individual patient's caries risk. Lesion detection aids can assist in the longitudinal monitoring of the behaviour of initial lesions. Copyright 2009 S. Karger AG, Basel

  2. PIACS: A System for the Automatic Detection, Categorization and Comparison of Scratch-Related Skin Lesions in Dermatology.

    PubMed

    Bruland, Philipp; Hänse, Waldemar; Schedel, Fiona; Ständer, Sonja; Fritz, Fleur

    2015-01-01

    In the treatment of chronic pruritus-related, scratch-induced skin lesions the categorization, counting and temporal comparison are common methodologies. The observation requires a good memory and expertise in this field to gain comparable findings for this time-consuming process. Digital image processing aims at supporting such manual detections. The objective is to develop a software tool for automatic image detection and comparison. The new photographic setting implies the usage of markers to derive the brightness and size of lesions. MATLAB has been used for the software development. The newly defined setting allows taking standardized images of pruritus-associated cutaneous lesions for detection and comparison. The tool named PIACS (Prurigo Image Analyzing and Comparing System) allows automatically detecting, categorizing and comparing lesions based on digital images.

  3. Detecting arsenic-related skin lesions: experiences from a large community-based survey in Bangladesh.

    PubMed

    Hore, Samar Kumar; Rahman, Mahfuzar; Yunus, Mohammad; Das, Chandra Shakhar; Yeasmin, Sultana; Ahmad, S K Akhtar; Sayed, M H Salim Ullah; Islam, Azm Maidul; Vahter, Marie; Persson, Lars Ake

    2007-04-01

    A cross-sectional survey was conducted in Matlab, Bangladesh, to determine the prevalence of skin lesions (a three-step procedure) associated with arsenic exposure and discuss validity and feasibility in relation to recommended screening algorithms. Cases with skin lesions were identified by screening above 4 years of age (n = 166,934). Trained field teams conducted a careful house-to-house screening and identified 1682 individuals with skin lesions, who were referred to physicians for confirmation. Physicians diagnosed 579 cases as probable and documented all these with digital photographs. Two experts inspected all photographs for consensus agreement that was reached for 504 cases. Using the experts' opinions as reference, the positive predictive value of the physicians' diagnosis was 87% (male = 82% vs. female = 94%; p < 0.01). The physicians had difficulties in separating arsenic-induced keratosis from differential diagnoses, while probability for correct diagnosis was high for arsenic-related pigmentation changes. Including information on current arsenic concentration in drinking water (which was masked at time of skin examination) or urine in the diagnostic algorithm should have increased the number of false negative cases. In the present transition of drinking water sources these markers of current exposure levels provide no information on past exposure. A 2-3 step procedure with house-to-house screening and clinic-based confirmation of arsenic-induced skin lesions is a feasible approach. Information on arsenic concentration in current water sources or in urine should not have improved the precision in the diagnosis. These results may have policy implications for community screening of arsenic-related skin lesions in Bangladesh and elsewhere.

  4. Lesion detectability in digital radiography

    NASA Astrophysics Data System (ADS)

    Gagne, Robert M.; Boswell, Jonathan S.; Myers, Kyle J.; Peter, Guillaume

    2001-06-01

    The usefulness of Fourier-based measures of imaging performance has come into question for the evaluation of digital imaging systems. Figures of merit such as detective quantum efficiency are relevant for linear, shift-invariant systems with stationary noise. However, no digital imaging system is shift invariant, and realistic images do not satisfy the stationarity condition. Our methods for task- based evaluation of imaging systems, based on lesion detectability, do not require such assumptions. We have computed the performance of Hotelling and nonprewhitening matched-filter observers for the task of lesion detection in digital radiography.

  5. Search field size and lesion detection performance

    NASA Astrophysics Data System (ADS)

    Tipnis, Sameer; Huda, Walter; Hardie, Andrew; Ogden, Kent

    2010-04-01

    In this study, we evaluated the ability of an observer to identify abnormal foci on CT and how that ability is affected by changing the search field size from a whole abdomen to the liver region alone. A 2-Alternate Forced Choice (2 AFC) experimental paradigm was used to quantify observer detection performance. Each AFC experiment yielded the intensity needed to achieve 92% accuracy in lesion detection (I92%). Abdominal images were obtained at an x-ray tube voltage of 120 kV with a CTDIvol of 20 mGy. Circular lesions were generated by projecting spheres onto the image plane, followed by blurring function. Five lesion sizes (5 mm, 7 mm, 10 mm, 12 mm, and 15 mm), and four readers who were extensively trained in AFC methodology, were used in the 2AFC experiments. Each experiment was repeated 4 times to improve the experimental precision, as well as to provide an estimate of experimental uncertainty. For each observer, the experimental order of the 40 experiments was randomized to eliminate learning curve and/or observer fatigue. We measured contrast detail slopes for both Abdomen and Liver search field size, and determined ratio of I92% value for Abdomen search field to the corresponding I92% for the Liver search field (i.e., Rabd:liv). Values of Rabd:liv provides quantitative indicator of the relative difficulty of detection lesions in the whole Abdomen relative to lesion detection restricted to the Liver. The slope of the contrast detail curve for the Abdomen search field was -0.03, whereas the corresponding slope for the Liver search field was -0.18. Rabd:liv ranged between 1.3 and 1.6, with an average of 1.4 +/- 0.1. The value of Rabd:liv monotonically increased from 1.35 for 5 mm lesions to nearly 1.6 for the largest 15 mm lesion. The results of our study indicate that limiting the area of search to the liver on a CT of the abdomen improves the detection of mass lesions. This finding is almost certainly related to the fact that the liver provides a relatively

  6. Penalized maximum-likelihood image reconstruction for lesion detection

    NASA Astrophysics Data System (ADS)

    Qi, Jinyi; Huesman, Ronald H.

    2006-08-01

    Detecting cancerous lesions is one major application in emission tomography. In this paper, we study penalized maximum-likelihood image reconstruction for this important clinical task. Compared to analytical reconstruction methods, statistical approaches can improve the image quality by accurately modelling the photon detection process and measurement noise in imaging systems. To explore the full potential of penalized maximum-likelihood image reconstruction for lesion detection, we derived simplified theoretical expressions that allow fast evaluation of the detectability of a random lesion. The theoretical results are used to design the regularization parameters to improve lesion detectability. We conducted computer-based Monte Carlo simulations to compare the proposed penalty function, conventional penalty function, and a penalty function for isotropic point spread function. The lesion detectability is measured by a channelized Hotelling observer. The results show that the proposed penalty function outperforms the other penalty functions for lesion detection. The relative improvement is dependent on the size of the lesion. However, we found that the penalty function optimized for a 5 mm lesion still outperforms the other two penalty functions for detecting a 14 mm lesion. Therefore, it is feasible to use the penalty function designed for small lesions in image reconstruction, because detection of large lesions is relatively easy.

  7. Imaging inflammatory acne: lesion detection and tracking

    NASA Astrophysics Data System (ADS)

    Cula, Gabriela O.; Bargo, Paulo R.; Kollias, Nikiforos

    2010-02-01

    It is known that effectiveness of acne treatment increases when the lesions are detected earlier, before they could progress into mature wound-like lesions, which lead to scarring and discoloration. However, little is known about the evolution of acne from early signs until after the lesion heals. In this work we computationally characterize the evolution of inflammatory acne lesions, based on analyzing cross-polarized images that document acne-prone facial skin over time. Taking skin images over time, and being able to follow skin features in these images present serious challenges, due to change in the appearance of skin, difficulty in repositioning the subject, involuntary movement such as breathing. A computational technique for automatic detection of lesions by separating the background normal skin from the acne lesions, based on fitting Gaussian distributions to the intensity histograms, is presented. In order to track and quantify the evolution of lesions, in terms of the degree of progress or regress, we designed a study to capture facial skin images from an acne-prone young individual, followed over the course of 3 different time points. Based on the behavior of the lesions between two consecutive time points, the automatically detected lesions are classified in four categories: new lesions, resolved lesions (i.e. lesions that disappear completely), lesions that are progressing, and lesions that are regressing (i.e. lesions in the process of healing). The classification our methods achieve correlates well with visual inspection of a trained human grader.

  8. Longitudinal assessment of cyst-like lesions of the knee and their relation to radiographic osteoarthritis and MRI-detected effusion and synovitis in patients with knee pain

    PubMed Central

    2010-01-01

    Introduction The purpose of the present study was to determine the prevalence of cystic lesions and cyst-like bursitides in subjects with frequent knee pain and to assess their relation to radiographic osteoarthritis (OA) severity; to describe bilaterality and size fluctuation of the lesions over 6 months; and to assess relations between the prevalence of synovium-lined lesions communicating with the joint capsule and severity of magnetic resonance imaging (MRI)-detected effusion and synovitis. Methods One hundred and sixty-three subjects (total 319 knees) aged 35 to 65 with chronic, frequent knee pain were included. Imaging with 3 Tesla MRI was performed at baseline and 6-month follow-up with the same protocols as those used in the Osteoarthritis Initiative. Severity of radiographic OA was assessed using the Kellgren-Lawrence grade (0 to 4). Severity of effusion and synovitis was graded 0 to 3 based on the Whole Organ Magnetic Resonance Imaging Score system. The associations of cysts and cyst-like bursitides and severity of radiographic OA, MRI-detected effusion and synovitis were analyzed using logistic regression controlling for clustering by person. The Wilcoxon signed-rank test was used to determine whether there was a significant change in the size of lesions between baseline and follow-up. Results At least one lesion (any type) was present in 222 (70%) knees. The most prevalent lesions were popliteal cysts (40%, 128/319), followed by subgastrocnemius bursitis (15%, 49/319) and proximal tibiofibular joint cysts (8%, 26/319). Bilateral lesions were seen in 49% of the subjects. Only popliteal cysts and subgastrocnemius bursitis showed a significant change in size (P < 0.001). No trend was observed between prevalence of any of the cyst-like lesions analyzed and the increasing radiographic OA severity. Increasing prevalence of subgastrocnemius bursitis was associated with increasing severity of effusion (P = 0.0072) and synovitis (P = 0.0033). Conclusions None of

  9. Vibration sonoelastography and the detectability of lesions.

    PubMed

    Parker, K J; Fu, D; Graceswki, S M; Yeung, F; Levinson, S F

    1998-11-01

    Vibration sonoelastography has been developed for the detection of hard lesions in relatively soft tissue. The basic concept is to propagate low-amplitude and low-frequency shear waves (with displacements below 0.1 mm and frequencies typically below 1000 Hz) through deep organs, and displaying the vibration response in real-time using advanced color Doppler imaging techniques. A hard inhomogeneity, such as a tumor, will produce a localized disturbance in the vibration pattern, forming the basis for detection even when the tumor is isoechoic on B-scan images. This paper focuses on the important quantitative issues concerning the detectability or inherent contrast of lesions. The specific factors of lesion size, relative stiffness and vibration frequency are studied using theoretical models, finite element methods and experimental measurements on tissue-mimicking materials. The results indicate that detectability increases with vibration (shear wave) frequency; however, loss mechanisms ultimately limit the penetration of higher vibration frequencies (in the kHz range).

  10. GC/MS/MS DETECTION OF EXTRACELLULAR KYNURENINE AND RELATED METABOLITES IN NORMAL AND LESIONED RAT BRAIN

    PubMed Central

    Notarangelo, Francesca M.; Wu, Hui-Qiu; Macherone, Anthony; Graham, David R.; Schwarcz, Robert

    2012-01-01

    We describe here a GC/MS/MS method for the sensitive and concurrent determination of extracellular tryptophan and the kynurenine pathway metabolites kynurenine, 3-hydroxykynurenine (3-HK) and quinolinic acid (QUIN) in rat brain. This metabolic cascade is increasingly linked to the pathophysiology of several neurological and psychiatric diseases. Methodological refinements, including optimization of MS conditions and addition of deuterated standards, resulted in assay linearity to the low nanomolar range. Measured in samples obtained by striatal microdialysis in vivo, basal levels of tryptophan, kynurenine and QUIN were 415, 89 and 8 nM, respectively, but 3-HK levels were below the limit of detection (<2 nM). Systemic injection of kynurenine (100 mg/kg, i.p.) did not affect extracellular tryptophan but produced detectable levels of extracellular 3-HK (peak after 2-3 h: ~50 nM) and raised extracellular QUIN levels (peak after 2 h: ~105 nM). The effect of this treatment on QUIN, but not on 3-HK, was potentiated in the NMDA-lesioned striatum. Our results indicate that the novel methodology, which allowed the measurement of extracellular kynurenine and 3-HK in the brain in vivo, will facilitate studies of brain kynurenines and of the interplay between peripheral and central kynurenine pathway function under physiological and pathological conditions. PMID:22239963

  11. Detection of Helicobacter pylori in Oral Lesions

    PubMed Central

    Irani, Soussan; Monsef Esfahani, Alireza; Bidari Zerehpoush, Farahnaz

    2013-01-01

    Background and aims. Helicobacter pylori is a microaerophilic gram-negative spiral organism. It is recognized as the etiologic factor for peptic ulcers, gastric adenocarcinoma and gastric lymphoma. Recently, it has been isolated from dental plaque and the dorsum of the tongue. This study was designed to assess the association between H. pylori and oral lesions such as ulcerative/inflammatory lesions, squamous cell carcinoma (SCC) and primary lymphoma. Materials and methods. A total of 228 biopsies diagnosed as oral ulcerative/inflammatory lesions, oral squamous cell carcinoma (OSCC) and oral primary lymphoma were selected from the archives of the Pathology Department. Thirty-two samples that were diagnosed as being without any pathological changes were selected as the control group. All the paraffin blocks were cut for hematoxylin and eosin staining to confirm the diagnoses and then the samples were prepared for immunohistochemistry staining. Data were collected and analyzed. Results. Chi-squared test showed significant differences between the frequency of H. pylori positivity in normal tissue and the lesions were examined (P=0.000). In addition, there was a statistically significant difference between the lesions examined (P=0.042). Chi-squared test showed significant differences between H. pylori positivity and different tissue types except inside the muscle layer as follows: in epithelium and in lamina propria (P=0.000), inside the blood vessels (P=0.003), inside the salivary gland duct (P=0.036), and muscle layer (P=0.122). Conclusion. There might be a relation between the presence of H. pylori and oral lesions. Therefore, early detection and eradication of H. pylori in high-risk patients are suggested. PMID:24578822

  12. Detecting and Treating Occlusal Caries Lesions

    PubMed Central

    Stolpe, M.; Meyer-Lueckel, H.; Paris, S.

    2015-01-01

    The health gains and costs resulting from using different caries detection strategies might not only depend on the accuracy of the used method but also the treatment emanating from its use in different populations. We compared combinations of visual-tactile, radiographic, or laser-fluorescence–based detection methods with 1 of 3 treatments (non-, micro-, and invasive treatment) initiated at different cutoffs (treating all or only dentinal lesions) in populations with low or high caries prevalence. A Markov model was constructed to follow an occlusal surface in a permanent molar in an initially 12-y-old male German patient over his lifetime. Prevalence data and transition probabilities were extracted from the literature, while validity parameters of different methods were synthesized or obtained from systematic reviews. Microsimulations were performed to analyze the model, assuming a German health care setting and a mixed public-private payer perspective. Radiographic and fluorescence-based methods led to more overtreatments, especially in populations with low prevalence. For the latter, combining visual-tactile or radiographic detection with microinvasive treatment retained teeth longest (mean 66 y) at lowest costs (329 and 332 Euro, respectively), while combining radiographic or fluorescence-based detections with invasive treatment was the least cost-effective (<60 y, >700 Euro). In populations with high prevalence, combining radiographic detection with microinvasive treatment was most cost-effective (63 y, 528 Euro), while sensitive detection methods combined with invasive treatments were again the least cost-effective (<59 y, >690 Euro). The suitability of detection methods differed significantly between populations, and the cost-effectiveness was greatly influenced by the treatment initiated after lesion detection. The accuracy of a detection method relative to a “gold standard” did not automatically convey into better health or reduced costs. Detection

  13. Detection of lesions in mammographic structure

    NASA Astrophysics Data System (ADS)

    Burgess, Arthur E.; Jacobson, Francine L.; Judy, Philip F.

    1999-05-01

    This paper is a report on very surprising results from recent work on detection of real lesions in digitized mammograms. The experiments were done using a novel experimental procedure with hybrid images. The lesions (signals) were real tumor masses extracted from breast tissue specimen radiographs. In the detection experiments, the tumors were added to digitized normal mammographic backgrounds. The results of this new work have been both novel and very surprising. Contrast thresholds increased with increasing lesion size for lesions larger than approximately 1 mm in diameter. Earlier work with white noise, radiographic image noise, computed tomography (CT) noise and some types of patient structure have accustomed us to a particular relationship between lesion size and contrast for constant detectability. All previous contrast/detail (CD) diagrams have been similar, the contrast threshold decreases as lesion size increases and flattens at large lesion sizes. The CD diagram for lesion detection in mammographic structure is completely different. It will be shown that this is a consequence of the power-law dependence of the projected breast tissue structure spectral density on spatial frequency. Mammographic tissue structure power spectra have the form P(f) equals B/f(beta ), with an average exponent of approximately 3 (range from 2 to 4), and are approximately isotropic (small angular dependence). Results for two-alternative forced-choice (2AFC) signal detection experiments using 4 tumor lesions and one mathematically generated signal will be presented. These results are for an unbiased selection of mammographic backgrounds. It is possible that an additional understanding of the effects of breast structure on lesion detectability can be obtained by investigating detectability in various classes of mammographic backgrounds. This will be the subject of future research.

  14. Small white matter lesion detection in cerebral small vessel disease

    NASA Astrophysics Data System (ADS)

    Ghafoorian, Mohsen; Karssemeijer, Nico; van Uden, Inge; de Leeuw, Frank E.; Heskes, Tom; Marchiori, Elena; Platel, Bram

    2015-03-01

    Cerebral small vessel disease (SVD) is a common finding on magnetic resonance images of elderly people. White matter lesions (WML) are important markers for not only the small vessel disease, but also neuro-degenerative diseases including multiple sclerosis, Alzheimer's disease and vascular dementia. Volumetric measurements such as the "total lesion load", have been studied and related to these diseases. With respect to SVD we conjecture that small lesions are important, as they have been observed to grow over time and they form the majority of lesions in number. To study these small lesions they need to be annotated, which is a complex and time-consuming task. Existing (semi) automatic methods have been aimed at volumetric measurements and large lesions, and are not suitable for the detection of small lesions. In this research we established a supervised voxel classification CAD system, optimized and trained to exclusively detect small WMLs. To achieve this, several preprocessing steps were taken, which included a robust standardization of subject intensities to reduce inter-subject intensity variability as much as possible. A number of features that were found to be well identifying small lesions were calculated including multimodal intensities, tissue probabilities, several features for accurate location description, a number of second order derivative features as well as multi-scale annular filter for blobness detection. Only small lesions were used to learn the target concept via Adaboost using random forests as its basic classifiers. Finally the results were evaluated using Free-response receiver operating characteristic.

  15. Detection of Human Papilloma Virus (HPV) in oral mucosa of women with cervical lesions and their relation to oral sex practices

    PubMed Central

    2010-01-01

    Background Previous studies have either investigated the relationship of HPV with oral cancer or the prevalence of HPV on the oral cavity. The purpose of this investigation was to study the prevalence of HPV in oral cavity of women with oral sex practices and cervical lesions. Methods Forty six (46) non-smokers and non-alcoholic patients attended the "Clínica de Displasias" of "Ciudad Juarez" were sampled. This population had a CIN diagnosis sometime between the previous six months. On previous consent they filled out a questionnaire related to their oral sex practices. Afterwards one swab from cheeks and another from palate/gum were taken; PCR was used to determine generic HPV, HPV16 and HPV18. Results Seventy two percent (72%) of the patients stated to have oral sex practices regularly which all of them were positive to HPV either in oral mucus, palate/gum or both. The total of the given results showed that 35% had HPV16; among those distributed in 26% with regular oral sex practices and 9% stated as never practiced oral sex. An association was found between oral HPV16 positivity and progression to cervical CIN advanced lesions. On the other hand HPV18 was not detected. The frequency of HPV16 was higher in buccal mucosa (23%) versus palate/gum (16%). Conclusions This study suggests that buccal HPV16 infection is associated with CIN progression. PMID:21129222

  16. Computer detection of stellate lesions in mammograms

    NASA Astrophysics Data System (ADS)

    Kegelmeyer, W. Philip, Jr.

    1992-06-01

    The three primary signs for which radiologists search when screening mammograms for breast cancer are stellate lesions, microcalcifications, and circumscribed lesions. Stellate lesions are of particular importance, as they are almost always associated with a malignancy. Further, they are often indicated only by subtle architectural distortions and so are in general easier to miss than the other signs. We have developed a method for the automatic detection of stellate lesions in digitized mammograms, and have tested them on image data where the presence or absence of malignancies is known. We extract image features from the known images, use them to grow binary decision trees, and use those trees to label each pixel of new mammograms with its probability of being located on an abnormality. The primary feature for the detection of stellate lesions is ALOE, analysis of local oriented edges, which is derived from an analysis of the histogram of edge orientations in local windows. Other features, based on the Laws texture energy measures, have been developed to respond to normal tissue, and so improve the false alarm performance of the entire system.

  17. Expression of cyclooxygenase-2 (COX-2) and Ki67 as related to disease severity and HPV detection in squamous lesions of the cervix.

    PubMed

    Sarian, Luis Otavio; Derchain, Sophie Françoise; Yoshida, Adriana; Vassallo, José; Pignataro, Francisco; De Angelo Andrade, Liliana Aparecida Lucci

    2006-09-01

    To assess the expression of cyclooxygenase (COX-2) and Ki67 in cervical squamous lesions in relation to disease severity and human papillomavirus (HPV) detection. For this cross-sectional study, 223 women subjected to diathermic conization of the cervix have been enrolled, between February 2001 and April 2004. All patients undertook pelvic examination, including colposcopy and collection of samples for Hybrid Capture II (HCII). Pathological assessment disclosed: 9 cases of normal epithelium/cervicitis, 33 CIN1, 28 CIN2, 146 CIN3 and 7 invasive squamous cell carcinomas. COX-2 and Ki67 protein expression was determined with immunohistochemistry. COX-2 immunoreactivity grading was based on the German ImmonoReactive score. The continuum percentage of positive cells was used for the assessment of nuclear Ki67 expression. Expression of COX-2 did not correlate with disease severity and with Ki67 expression. The HPV detection rates did not differ significantly across COX-2 protein expression strata, ranging from negative to strong expression. Ki67 expression, however, was higher in the CIN3 group (P = 0.001) as compared to the specimens rendered as normal/cervicitis. COX-2 protein expression did not correlate with disease severity or Ki67 expression.

  18. Lesion border detection in dermoscopy images.

    PubMed

    Celebi, M Emre; Iyatomi, Hitoshi; Schaefer, Gerald; Stoecker, William V

    2009-03-01

    Dermoscopy is one of the major imaging modalities used in the diagnosis of melanoma and other pigmented skin lesions. Due to the difficulty and subjectivity of human interpretation, computerized analysis of dermoscopy images has become an important research area. One of the most important steps in dermoscopy image analysis is the automated detection of lesion borders. In this article, we present a systematic overview of the recent border detection methods in the literature paying particular attention to computational issues and evaluation aspects. Common problems with the existing approaches include the acquisition, size, and diagnostic distribution of the test image set, the evaluation of the results, and the inadequate description of the employed methods. Border determination by dermatologists appears to depend upon higher-level knowledge, therefore it is likely that the incorporation of domain knowledge in automated methods will enable them to perform better, especially in sets of images with a variety of diagnoses.

  19. Lesion Border Detection in Dermoscopy Images

    PubMed Central

    Celebi, M. Emre; Schaefer, Gerald; Iyatomi, Hitoshi; Stoecker, William V.

    2009-01-01

    Background Dermoscopy is one of the major imaging modalities used in the diagnosis of melanoma and other pigmented skin lesions. Due to the difficulty and subjectivity of human interpretation, computerized analysis of dermoscopy images has become an important research area. One of the most important steps in dermoscopy image analysis is the automated detection of lesion borders. Methods In this article, we present a systematic overview of the recent border detection methods in the literature paying particular attention to computational issues and evaluation aspects. Conclusion Common problems with the existing approaches include the acquisition, size, and diagnostic distribution of the test image set, the evaluation of the results, and the inadequate description of the employed methods. Border determination by dermatologists appears to depend upon higher-level knowledge, therefore it is likely that the incorporation of domain knowledge in automated methods will enable them to perform better, especially in sets of images with a variety of diagnoses. PMID:19121917

  20. Detectability of artificial lesions in anthropomorphic virtual breast phantoms of variable glandular fraction

    NASA Astrophysics Data System (ADS)

    Sauer, Thomas J.; Graff, Christian G.; Zeng, Rongping; Santana, Maira; Sturgeon, Gregory M.; Bosmans, Hilde; Glick, Stephen J.; Chen, Xinyuan C.; Segars, W. P.; Lo, Joseph Y.

    2017-03-01

    This work seeks to utilize a cohort of computational, patient-based breast phantoms and anthropomorphic lesions inserted therein to determine trends in breast lesion detectability as a function of several clinically relevant variables. One of the measures of local density proposed gives rise to a statistically significant trend in lesion detectability, and it is apparent that lesion type is also a predictor of relative detectability.

  1. Detecting circumscribed lesions with the Hough transform

    SciTech Connect

    Groshong, B.R; Kegelmeyer, W.P., Jr

    1996-01-11

    We have designed and implemented a circumscribed lesion detection algorithm, based on the Hough Transform, which will detect zero or more approximately circular structures in a mammogram over a range of radii from a few pixels to nearly the size of the breast. We address the geometrical behavior of peaks in Hough parameter space (x,y,r) for both the true radius of a circular structure in the image (r = r{sub o}), and for the parameter r as it passes through this radius. In addition, we evaluate peaks in Hough parameter space by re-analyzing the underlying mammogram in the vicinity of the circular disk indicated by the peak. Discs suggested by the resulting peaks are accumulated in a feature image, scaled by a measure of their quality. These results are then rectified with respect to image contrast extremes and average value. The result is a feature with a continuously scaled pixel level output which suggests the likelihood that a pixel is located inside a circular structure, irrespective of the radius of the structure and overall mammogram contrast. These features are evaluated fast qualitative and quantitative performance metrics which permit circumscribed lesion detection features to be initially evaluated without a full end-to-end classification experiment.

  2. A massive lesion detection algorithm in mammography.

    PubMed

    Fauci, Francesco; Raso, Giuseppe; Magro, Rosario; Forni, Giustina; Lauria, Adele; Bagnasco, Stefano; Cerello, Piergiorgio; Cheran, Sorin C; Lopez Torres, Ernesto; Bellotti, Robero; Carlo, Francesco De; Gargano, Gianfranco; Tangaro, Sonia; Mitri, Ivan De; Nunzio, Giorgio De; Cataldo, Rossella

    A new algorithm for massive lesion detection in mammography is presented. The algorithm consists in three main steps: 1) reduction of the dimension of the image to be processed through the identification of regions of interest (roi) as candidates for massive lesions; 2) characterization of the RoI by means of suitable feature extraction; 3) pattern classification through supervised neural networks. Suspect regions are detected by searching for local maxima of the pixel grey level intensity. A ring of increasing radius, centered on a maximum, is considered until the mean intensity in the ring decreases to a defined fraction of the maximum. The ROIS thus obtained are described by average, variance, skewness and kurtosis of the intensity distributions at different fractions of the radius. A neural network approach is adopted to classify suspect pathological and healthy pattern. The software has been designed in the framework of the INFN (Istituto Nazionale Fisica Nucleare) research project GPCALMA (Grid Platform for Calma) which recruits physicists and radiologists from different Italian Research Institutions and hospitals to develop software for breast cancer detection.

  3. Visual discrimination modeling of lesion detectability

    NASA Astrophysics Data System (ADS)

    Johnson, Jeffrey P.; Lubin, Jeffrey; Nafziger, John S.; Chakraborty, Dev P.

    2002-04-01

    The Sarnoff JNDmetrix visual discrimination model (VDM) was applied to predict human psychophysical performance in the detection of simulated mammographic lesions. Contrast thresholds for the detection of synthetic Gaussian masses on mean backgrounds and simulated mammographic backgrounds were measured in two-alternative, forced-choice (2AFC) trials. Experimental thresholds for 2-D Gaussian signal detection decreased with increasing signal size on mean backgrounds and on 1/f3 filtered noise images presented with identical (paired) backgrounds. For 2AFC presentations of different (unpaired) filtered noise backgrounds, detection thresholds increased with increasing signal diameter, consistent with a decreasing signal-to-noise ratio. Thresholds for mean and paired filtered noise backgrounds were used to calibrate a new low-pass, spatial-frequency channel in the VDM. The calibrated VDM was able to predict accurate detection thresholds for Gaussian signals on mean and paired 1/f3 filtered noise backgrounds. To simulate noise-limited detection thresholds for unpaired backgrounds, an approach is outlined for the development of a VDM-based model observer based on statistical decision theory.

  4. Diffusion-weighted magnetic resonance imaging for the detection of ischemic brain lesions in coronary artery bypass graft surgery: relation to extracorporeal circulation and heparinization.

    PubMed

    Mirow, N; Zittermann, A; Körperich, H; Börgermann, J; Koertke, H; Knobl, H; Gieseke, J; Ostertun, B; Coskun, T; Kleesiek, K; Burchert, W; Gummert, J F

    2011-02-01

    Cognitive decline is a well recognized complication after on-pump coronary artery bypass graft (CABG) surgery. We investigated whether the design of extracorporeal circulation (ECC) and the extent of perioperative heparinization have an impact on neurological dysfunction. Sixty-three CABG surgery patients were randomly perfused with an uncoated ECC-set (group A) or with two different heparin-coated ECC-sets (groups B and C). In groups A and B, systemic heparin was given in doses of 400 IU/kg body weight, whereas group C received 150 IU/kg body weight. ECC sets in group C included a diagonal pump and low priming as opposed to roller pumps in groups A and B. Furthermore, in group C blood contact to surfaces other than endothelium and heparin coated material was eliminated. Brain lesions were detected by diffusion-weighted magnetic resonance imaging (DWI). Neurological complications were assessed clinically until discharge (manifest motoric, sensitive or cognitive disturbance). Biochemical coagulation and inflammation parameters were measured pre-, peri-, and postoperatively. No major neurological events were observed in either group until discharge. DWIs showed 61 new lesions in 19 of 45 patients who terminated all MRI study procedures. Number and volume of the lesions did not differ between groups (P>0.05). Biochemical and inflammatory parameters showed the expected time courses and variations between groups. Ischemic brain lesions are frequently observed in CABG surgery patients but are neither associated with clinically relevant neurological complications nor with ECC set-up and intraoperative heparin dosage. DWI may help in the development of new surgical strategies to reduce postoperative brain damage.

  5. High-Grade Cervical Intraepithelial Neoplasia Detected by Colposcopy-Directed or Random Biopsy Relative to Age, Cytology, Human Papillomavirus 16, and Lesion Size.

    PubMed

    Chen, Qing; Du, Hui; Pretorius, Robert G; Wang, Chun; Yang, Bin; Wang, Guixiang; Tang, Jinlong; Belinson, Jerome L; Wu, Ruifang

    2016-07-01

    The aim of the study was to determine whether p16 positive/cervical intraepithelial neoplasia (CIN) 2, 3, and cancer (p16 + CIN 2/3+) detected by colposcopy-directed or random biopsy differ by age, referral cytology, human papillomavirus (HPV) 16, and lesion size. Data from the Shenzhen Cervical Cancer Screening Trial II where, at colposcopy, women who had directed and random cervical biopsies were reviewed to find women with CIN 2, 3, or cancer; 227 such women identified had their paraffin-embedded tissue blocks recut, reviewed, and then immune stained for p16. Data were analyzed by χ, Fisher exact test, and linear regression. After histopathologic review and p16 staining of CIN 2, 175 women were diagnosed with p16 + CIN 2/3+. When compared with those diagnosed by colposcopy-directed biopsy (n = 138), those diagnosed by random biopsy (n = 37) were more likely to have Cytology-Lo (cytology of negative, atypical squamous cells of undetermined significance, or low-grade squamous intraepithelial lesion; p = .07), less likely to have HPV 16 (p = .041), more likely to be 51 years or older (p = .022), and more likely to have 1 quadrant lesions (p < .001). Logistic regression analysis showed p16 + CIN 2/3+ diagnosed by random biopsy was predicted by 1 quadrant lesions (p < .0001) and age of 51 years or older (p = .03) but not by Cytology-Lo (p = .71) nor HPV 16 (p = .26). Women with p16 + CIN 2/3+ diagnosed by random biopsy are older and less likely to have HPV 16; hence, CIN diagnosed by random biopsy may not be as virulent as CIN diagnosed by colposcopy-directed biopsy. Regardless, we advise that CIN diagnosed by random biopsy be viewed like CIN diagnosed by colposcopy-directed biopsy.

  6. One-step duplex polymerase chain reaction for the detection of swinepox and vaccinia viruses in skin lesions of swine with poxvirus-related disease.

    PubMed

    Medaglia, Maria Luiza G; Sá, Natália M B; Correa, Isadora A; Costa, Luciana J; Damaso, Clarissa R

    2015-07-01

    Infection of pigs with swinepox virus (SWPV) was reported in Brazil in 2011. SWPV causes a systemic pustular disease in pigs and the symptoms are clinically indistinguishable from those caused by vaccinia virus (VACV) infection. Pigs infected with VACV have been reported in various countries; however, VACV is endemic in Brazil, India and other countries, where it affects mainly dairy cows, dairy buffaloes and dairy workers causing localized pustules. The transmission of VACV to other susceptible hosts has also been detected in Brazil. Therefore, VACV should be investigated as a possible etiologic agent of pustular skin disorders in pigs. This work describes the development of a one-step duplex assay to detect swinepox and vaccinia viruses simultaneously in skin lesions of pigs with generalized pustular disease. The investigation of VACV infection in pigs is important in countries where this zoonosis is endemic and should be differentiated from SWPV infection.

  7. Optimized lesion detection in digital breast tomosynthesis

    NASA Astrophysics Data System (ADS)

    Chawla, Amarpreet S.; Samei, Ehsan; Lo, Joseph Y.

    2009-02-01

    While diagnostic improvement via breast tomosynthesis has been notable, the full potential of tomosynthesis has not yet been realized. This is because of the complex task of optimizing multiple parameters that constitute image acquisition and thus affect tomosynthesis performance. Those parameters include dose, number of angular projections, and the total angular span of those projections. In this study, we investigated the effects of acquisition parameters, independent of each other, on the overall diagnostic image quality of tomosynthesis. Five mastectomy specimens were imaged using a prototype tomosynthesis system. 25 angular projections of each specimen were acquired at 6.2 times typical single-view mammographic dose level. Images at lower dose levels were then simulated using a noise modification routine. Each projection image was supplemented with 84 simulated 3 mm 3D lesions embedded at the center of 84 non-overlapping ROIs. The projection images were then reconstructed using a filtered-back projection (FBP) algorithm at 224 different combinations of acquisition parameters to investigate which one of the many possible combinations maximized performance. Performance was evaluated in terms of a Laguerre-Gauss channelized Hotelling observer model-based measure of lesion detectability. Results showed that performance improved with an increase in the total acquisition dose level and the angular span. At a constant dose level and angular span, the performance rolled-off beyond a certain number of projections, indicating that simply increasing the number of projections in tomosynthesis may not necessarily improve its performance. The best performance was obtained with 15-17 projections spanning an angular arc of ~45° - the maximum tested in our study, and for an acquisition dose equal to single-view mammography. The optimization framework developed in this framework is applicable to other reconstruction techniques and other multi-projection systems.

  8. Automatic detection of ureter lesions in CT urography

    NASA Astrophysics Data System (ADS)

    Exell, Trevor; Hadjiiski, Lubomir; Chan, Heang-Ping; Cha, Kenny H.; Caoili, Elaine M.; Cohan, Richard H.; Wei, Jun; Zhou, Chuan

    2016-03-01

    We are developing a CAD system for automated detection of ureter abnormalities in multi-detector row CT urography (CTU). Our CAD system consists of two stages. The first stage automatically tracks the ureter via the previously proposed COmbined Model-guided Path-finding Analysis and Segmentation System (COMPASS). The second stage consists of lesion enhancement filtering, adaptive thresholding, edge extraction, and noise removal. With IRB approval, 36 cases were collected from patient files, including 15 cases (17 ureters with 32 lesions) for training, and 10 abnormal cases (11 ureters with 17 lesions) and 11 normal cases (22 ureters) for testing. All lesions were identified by experienced radiologists on the CTU images and COMPASS was able to track the ureters in 100% of the cases. The average lesion size was 5.1 mm (range: 2.1 mm - 21.9 mm) for the training set and 6.1 mm (range: 2.0 mm - 18.9 mm) for the test set. The average conspicuity was 4.1 (range: 2 to 5) and 3.9 (range: 1 to 5) on a scale of 1 to 5 (5 very subtle), for the training and test sets, respectively. The system achieved 90.6% sensitivity at 2.41 (41/17) FPs/ureter for the training set and 70.6% sensitivity at 2 (44/22) FPs/normal ureter for the test set. These initial results demonstrate the feasibility of the CAD system to track the ureter and detect ureter cancer of medium conspicuity and relatively small sizes.

  9. Detection of endometrial lesions by degree of linear polarization maps

    NASA Astrophysics Data System (ADS)

    Kim, Jihoon; Fazleabas, Asgerally; Walsh, Joseph T.

    2010-02-01

    Endometriosis is one of the most common causes of chronic pelvic pain and infertility and is characterized by the presence of endometrial glands and stroma outside of the uterine cavity. A novel laparoscopic polarization imaging system was designed to detect endometriosis by imaging endometrial lesions. Linearly polarized light with varying incident polarization angles illuminated endometrial lesions. Degree of linear polarization image maps of endometrial lesions were constructed by using remitted polarized light. The image maps were compared with regular laparoscopy image. The degree of linear polarization map contributed to the detection of endometriosis by revealing structures inside the lesion. The utilization of rotating incident polarization angle (IPA) for the linearly polarized light provides extended understanding of endometrial lesions. The developed polarization system with varying IPA and the collected image maps could provide improved characterization of endometrial lesions via higher visibility of the structure of the lesions and thereby improve diagnosis of endometriosis.

  10. Incidental Breast Lesions Detected on Computed Thorax Tomography

    PubMed Central

    Poyraz, Necdet; Emlik, Ganime Dilek; Keskin, Suat; Kalkan, Havva

    2015-01-01

    Objective Although mammography is the primary imaging method of the breast, incidental benign and malignant breast lesions are increasingly being detected on computed tomographies (CTs) performed to detect different pathologies. Therefore, the detection and accurate identification of these lesions is important. In this study, we aimed to evaluate the frequency, morphological features, and results of incidental breast lesions on CTs performed for the detection of extramammarian pathologies. Materials and Methods Incidental breast lesions on CTs performed in our department between 2011 and 2013 were evaluated. Patients who had previously diagnosed breast lesions were excluded from the study. The inclusion criteria were histopathologic diagnose and being followed-up for at least 2 years. Results The study population consisted of 33 women whose mean age was 55±1.38 (37–78) years. Of the 33 women, 12 (36%) had malignant and 21 (64%) had benign or normal findings. The most common malignant lesion was invasive ductal carcinoma, and the most common benign lesion was fibroadenoma. Ill-defined contour and lymphadenopathy in malignant lesions and well-defined contour in benign lesions were the most important CT findings. Conclusion Breast must be carefully evaluated if it is included in the scans. An accurate report of breast lesions gives an opportunity for early diagnosis and treatment.

  11. Evaluation of scintillation cameras by spherical lesion detectability.

    PubMed

    Shinohara, H; Koga, Y

    1980-12-01

    The lesion detectability with a scintillation camera as a function of count density was determined for the four spherical cold lesions with diameter 0.9-2.5 cm (in square root 2 step) within a uniform background activity. It can be seen from the curves that the lesion detectability increases with an increase in count density until 2 kcounts/cm2, however it does not appreciably improve for count densities above 2 kcounts/cm2. The curves also show that, for a giving count density, the lesion detectability decreases as the lesion size or object contrast decreases. From these curves minimum count density required for recognition of each cold lesion is deduced. This value is applied to the evaluation of scintillation camera system.

  12. A Channelized Hotelling Observer Study of Lesion Detection in SPECT MAP Reconstruction Using Anatomical Priors

    PubMed Central

    Kulkarni, S.; Khurd, P.; Hsiao, I.; Zhou, L.; Gindi, G.

    2010-01-01

    In emission tomography, anatomical side information, in the form of organ and lesion boundaries, derived from intra-patient coregistered CT or MR scans can be incorporated into the reconstruction. Our interest is in exploring the efficacy of such side information for lesion detectability. To assess detectability we used the SNR of a channelized Hotelling observer and a signal-known exactly/background known exactly detection task. In simulation studies we incorporated anatomical side information into a SPECT MAP (maximum a posteriori) reconstruction by smoothing within but not across organ or lesion boundaries. A non-anatomical prior was applied by uniform smoothing across the entire image. We investigated whether the use of anatomical priors with organ boundaries alone or with perfect lesion boundaries alone would change lesion detectability relative to the case of a prior with no anatomical information. Furthermore, we investigated whether any such detectability changes for the organ-boundary case would be a function of the distance of the lesion to the organ boundary. We also investigated whether any detectability changes for the lesion-boundary case would be a function of the degree of proximity, i.e. a difference in the radius of the true functional lesion and the radius of the anatomical lesion boundary. Our results showed almost no detectability difference with vs without organ boundaries at any lesion-to-organ boundary distance. Our results also showed no difference in lesion detectability with and without lesion boundaries, and no variation of lesion detectability with degree of proximity. PMID:17664562

  13. Computer aided detection of oral lesions on CT images

    NASA Astrophysics Data System (ADS)

    Galib, S.; Islam, F.; Abir, M.; Lee, H. K.

    2015-12-01

    Oral lesions are important findings on computed tomography (CT) images. In this study, a fully automatic method to detect oral lesions in mandibular region from dental CT images is proposed. Two methods were developed to recognize two types of lesions namely (1) Close border (CB) lesions and (2) Open border (OB) lesions, which cover most of the lesion types that can be found on CT images. For the detection of CB lesions, fifteen features were extracted from each initial lesion candidates and multi layer perceptron (MLP) neural network was used to classify suspicious regions. Moreover, OB lesions were detected using a rule based image processing method, where no feature extraction or classification algorithm were used. The results were validated using a CT dataset of 52 patients, where 22 patients had abnormalities and 30 patients were normal. Using non-training dataset, CB detection algorithm yielded 71% sensitivity with 0.31 false positives per patient. Furthermore, OB detection algorithm achieved 100% sensitivity with 0.13 false positives per patient. Results suggest that, the proposed framework, which consists of two methods, has the potential to be used in clinical context, and assist radiologists for better diagnosis.

  14. Lesion conspicuity and AFROC performance in pulmonary nodule detection

    NASA Astrophysics Data System (ADS)

    Manning, David; Ethell, Susan C.

    2002-04-01

    A test bank of verified chest radiographs was compiled for visual search experiments. The purpose was to investigate human performance in the detection of significant pulmonary nodules. Synthesized nodules supplemented native lesions. The distribution of all the lesions in the lung fields was consistent with the naturally occurring locations of these features. A measure of the physical characteristics of the lesions was derived in order to approximate the conspicuity of the synthetic to the natural nodules. The measure of conspicuity was given as (chi) =Tan(theta-1)S/N where (theta) is the maximum slope angle to the edge of the lesion profile, S is the mean pixel value of the lesion profile taken in four orientations, and N is the mean background pixel value taken in four orientations over one lesion dimension adjacent to the lesion. The variation in (chi) for each of the 81 lesions (46 natural and 35 synthetic) was plotted against SNR and edge angle. The influence of edge angle on the resulting (chi) values was more powerful than SNR for all the lesions in this experiment. Although there was an overall significant difference in (chi) values (p=0.015), observers were unable to distinguish synthetic from native lesions. Observer performance in nodule detection was measured by AFROC and supplemented with visual search recording. Correlation of AFROC scores and the (chi) values has shown no overall relationship (R2=0.0452) and this surprising result may be partly explained through inspection of the visual search recordings.

  15. Multiple Sclerosis Lesion Detection Using Constrained GMM and Curve Evolution

    PubMed Central

    Freifeld, Oren; Greenspan, Hayit; Goldberger, Jacob

    2009-01-01

    This paper focuses on the detection and segmentation of Multiple Sclerosis (MS) lesions in magnetic resonance (MRI) brain images. To capture the complex tissue spatial layout, a probabilistic model termed Constrained Gaussian Mixture Model (CGMM) is proposed based on a mixture of multiple spatially oriented Gaussians per tissue. The intensity of a tissue is considered a global parameter and is constrained, by a parameter-tying scheme, to be the same value for the entire set of Gaussians that are related to the same tissue. MS lesions are identified as outlier Gaussian components and are grouped to form a new class in addition to the healthy tissue classes. A probability-based curve evolution technique is used to refine the delineation of lesion boundaries. The proposed CGMM-CE algorithm is used to segment 3D MRI brain images with an arbitrary number of channels. The CGMM-CE algorithm is automated and does not require an atlas for initialization or parameter learning. Experimental results on both standard brain MRI simulation data and real data indicate that the proposed method outperforms previously suggested approaches, especially for highly noisy data. PMID:19756161

  16. Intestinal lesions in pediatric Crohn disease: comparative detectability among pulse sequences at MR enterography.

    PubMed

    Sohn, Beomseok; Kim, Myung-Joon; Koh, Hong; Han, Kyung Hwa; Lee, Mi-Jung

    2014-07-01

    Variable sequences can be used in MR enterography, and no consensus exists for the best protocol in children with Crohn disease. To compare the lesion detectability of various MR enterography sequences and to correlate the findings of these sequences with the Pediatric Crohn's Disease Activity Index (PCDAI) in children with Crohn disease. Children with clinically or pathologically confirmed Crohn disease underwent MR enterography, including a single-shot fast spin-echo (SSFSE) sequence, motility imaging (coronal 2-D balanced fast field echo), diffusion-weighted imaging (DWI), and dynamic contrast enhancement imaging (including arterial, portal and delayed phases). The lesion detectability of each sequence was graded 0-2 for each involved bowel segment. The lesion detectability and PCDAI result on different sequences were compared using the weighted least squares method and Student's t-test, respectively. Fifteen children (11 boys, 4 girls, mean age 13.7 ± 1.4 years) with a total of 41 lesions were included in this study. All lesions detected in more than two sequences were visible on the single-shot fast spin-echo (SSFSE) sequence. The relative lesion detection rate was 78.1% on motility imaging, 90.2% on DWI, and 92.7% on arterial, 95.1% on portal and 95.1% on delayed phase imaging. Compared to the SSFSE sequence, motility imaging (P < 0.001) and DWI (P = 0.039) demonstrated lower detectability. The mean PCDAI result in the detected lesions was statistically higher only on dynamic enhancement imaging (P < 0.001). All MR enterography sequences were found to have relatively high lesion detectability in children with Crohn disease, while motility imaging showed the lowest lesion detectability. Lesions detected on dynamic enhancement imaging showed a higher PCDAI result, which suggests that this sequence is specific for active inflammation.

  17. Resecting without detecting the lesion in extratemporal lobe epilepsy?

    PubMed

    Henry, Thomas R

    2014-03-18

    Nonlesional extratemporal lobe epilepsy (ETLE) often persists following resection of the site of ictal onset, localized with definitive intracranial EEG recordings.(1,2) In lesional ETLE, however, lesionectomy with resection of a single electrophysiologically defined ictal onset (ictogenic) zone often stops seizures immediately and permanently.(1,2) In temporal lobe epilepsy (TLE), a single ictogenic site can be resected, either with an accompanying lesion or in the absence of an MRI-detected lesion, and is a highly efficacious epilepsy therapy.(2) Efforts to increase surgical efficacy in nonlesional ETLE have focused on localization by functional imaging to substitute for lesion localization by structural imaging.

  18. Optimization of PET system design for lesion detection

    SciTech Connect

    Qi, Jinyi

    2000-10-13

    Traditionally, the figures of merit used in designing a PET scanner are spatial resolution, noise equivalent count rate, noise equivalent sensitivity, etc. These measures, however, do not directly reflect the lesion detectability using the PET scanner. Here we propose to optimize PET scanner design directly for lesion detection. The signal-to-noise ratio (SNR) of lesion detection can be easily computed using the theoretical expressions that we have previously derived. Because no time consuming Monte Carlo simulation is needed, the theoretical expressions allow evaluation of a large range of parameters. The PET system parameters can then be chosen to achieve the maximum SNR for lesion detection. The simulation study shown in this paper was focused a single ring PET scanner without depth of interaction measurement. Randoms and scatters were also ignored.

  19. Optical mammography combined with fluorescence imaging: lesion detection using scatterplots

    PubMed Central

    Leproux, Anaïs; van der Voort, Marjolein; van der Mark, Martin B.; Harbers, Rik; van de Ven, Stephanie M. W. Y.; van Leeuwen, Ton G.

    2011-01-01

    Using scatterplots of 2 or 3 parameters, diffuse optical tomography and fluorescence imaging are combined to improve detectability of breast lesions. Small or low contrast phantom-lesions that were missed in the optical and fluorescence images were detected in the scatterplots. In patient measurements, all tumors were visible and easily differentiated from artifacts and areolas in the scatterplots. The different rate of intake and wash out of the fluorescent contrast agent in the healthy versus malignant tissues was also observed in the scatterplot: this information can be used to discriminate malignant lesion from normal structures. PMID:21483622

  20. Automatic detection of red lesions in digital color fundus photographs.

    PubMed

    Niemeijer, Meindert; van Ginneken, Bram; Staal, Joes; Suttorp-Schulten, Maria S A; Abràmoff, Michael D

    2005-05-01

    The robust detection of red lesions in digital color fundus photographs is a critical step in the development of automated screening systems for diabetic retinopathy. In this paper, a novel red lesion detection method is presented based on a hybrid approach, combining prior works by Spencer et al. (1996) and Frame et al. (1998) with two important new contributions. The first contribution is a new red lesion candidate detection system based on pixel classification. Using this technique, vasculature and red lesions are separated from the background of the image. After removal of the connected vasculature the remaining objects are considered possible red lesions. Second, an extensive number of new features are added to those proposed by Spencer-Frame. The detected candidate objects are classified using all features and a k-nearest neighbor classifier. An extensive evaluation was performed on a test set composed of images representative of those normally found in a screening set. When determining whether an image contains red lesions the system achieves a sensitivity of 100% at a specificity of 87%. The method is compared with several different automatic systems and is shown to outperform them all. Performance is close to that of a human expert examining the images for the presence of red lesions.

  1. Detection of serous precursor lesions in resected fallopian tubes from patients with benign diseases and a relatively low risk for ovarian cancer.

    PubMed

    Nishida, Naoyo; Murakami, Fumihiro; Higaki, Koichi

    2016-06-01

    The frequency of ovarian cancers in Japan has increased; however, doubts have been raised concerning the mechanism by which high-grade serous adenocarcinomas (HGSCs) arise. Conventionally, HGSC is thought to originate from the ovarian surface epithelium or epithelial inclusion cyst. However, recent data indicate that HGSCs may in fact develop from precursor lesions in the fallopian tube, including epithelia with a p53 signature, serous tubal intraepithelial carcinomas (STICs), secretory cell outgrowths (SCOUTs), and tubal intraepithelial lesions in transition (TILT). Here, we determined the frequency of these fallopian tube precursors in surgically excised samples from 123 patients with benign pelvic diseases. We identified 12 cases with a p53 signature (9.7%), 26 with observable SCOUTs (21.1%), and 4 with TILT (3.2%), but no STIC cases. Although the lifetime risk for developing ovarian cancer is only around 1.4% for women without germ-line mutations, it is important to evaluate the presence of precursor lesions to understand HGSC pathogenesis better. Taken together, salpingectomy appears to be an option for women who are past their childbearing age and plan to undergo elective pelvic surgery. To our knowledge, this is the first study to investigate the presence of these specific precursors post-salpingectomy in low-risk patients.

  2. Lesion detection and quantitation of positron emission mammography

    SciTech Connect

    Qi, Jinyi; Huesman, Ronald H.

    2001-12-01

    A Positron Emission Mammography (PEM) scanner dedicated to breast imaging is being developed at our laboratory. We have developed a list mode likelihood reconstruction algorithm for this scanner. Here we theoretically study the lesion detection and quantitation. The lesion detectability is studied theoretically using computer observers. We found that for the zero-order quadratic prior, the region of interest observer can achieve the performance of the prewhitening observer with a properly selected smoothing parameter. We also study the lesion quantitation using the test statistic of the region of interest observer. The theoretical expressions for the bias, variance, and ensemble mean squared error of the quantitation are derived. Computer simulations show that the theoretical predictions are in good agreement with the Monte Carlo results for both lesion detection and quantitation.

  3. Automated Detection of Lupus White Matter Lesions in MRI

    PubMed Central

    Roura, Eloy; Sarbu, Nicolae; Oliver, Arnau; Valverde, Sergi; González-Villà, Sandra; Cervera, Ricard; Bargalló, Núria; Lladó, Xavier

    2016-01-01

    Brain magnetic resonance imaging provides detailed information which can be used to detect and segment white matter lesions (WML). In this work we propose an approach to automatically segment WML in Lupus patients by using T1w and fluid-attenuated inversion recovery (FLAIR) images. Lupus WML appear as small focal abnormal tissue observed as hyperintensities in the FLAIR images. The quantification of these WML is a key factor for the stratification of lupus patients and therefore both lesion detection and segmentation play an important role. In our approach, the T1w image is first used to classify the three main tissues of the brain, white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF), while the FLAIR image is then used to detect focal WML as outliers of its GM intensity distribution. A set of post-processing steps based on lesion size, tissue neighborhood, and location are used to refine the lesion candidates. The proposal is evaluated on 20 patients, presenting qualitative, and quantitative results in terms of precision and sensitivity of lesion detection [True Positive Rate (62%) and Positive Prediction Value (80%), respectively] as well as segmentation accuracy [Dice Similarity Coefficient (72%)]. Obtained results illustrate the validity of the approach to automatically detect and segment lupus lesions. Besides, our approach is publicly available as a SPM8/12 toolbox extension with a simple parameter configuration. PMID:27570507

  4. Automatic colonic lesion detection and tracking in endoscopic videos

    NASA Astrophysics Data System (ADS)

    Li, Wenjing; Gustafsson, Ulf; A-Rahim, Yoursif

    2011-03-01

    The biology of colorectal cancer offers an opportunity for both early detection and prevention. Compared with other imaging modalities, optical colonoscopy is the procedure of choice for simultaneous detection and removal of colonic polyps. Computer assisted screening makes it possible to assist physicians and potentially improve the accuracy of the diagnostic decision during the exam. This paper presents an unsupervised method to detect and track colonic lesions in endoscopic videos. The aim of the lesion screening and tracking is to facilitate detection of polyps and abnormal mucosa in real time as the physician is performing the procedure. For colonic lesion detection, the conventional marker controlled watershed based segmentation is used to segment the colonic lesions, followed by an adaptive ellipse fitting strategy to further validate the shape. For colonic lesion tracking, a mean shift tracker with background modeling is used to track the target region from the detection phase. The approach has been tested on colonoscopy videos acquired during regular colonoscopic procedures and demonstrated promising results.

  5. Natural course of keratoacanthoma and related lesions after partial biopsy: clinical analysis of 66 lesions.

    PubMed

    Takai, Toshihiro; Misago, Noriyuki; Murata, Yozo

    2015-04-01

    There is some confusion regarding the classification of keratoacanthoma (KA) and related lesions that have crateriform architecture. We examined the clinical courses of 66 KA lesions and related lesions after a partial biopsy to clarify the nosological concept of KA. We histopathologically classified these lesions into five types: (i) KA at various stages (53 lesions); (ii) KA-like squamous cell carcinoma (SCC) (3 lesions); (iii) KA with malignant transformation (3 lesions); (iv) infundibular SCC (5 lesions); and (v) crateriform SCC arising from solar keratosis (2 lesions). We analyzed the clinical course in each group. The regression rate of KA was 98.1% and that of KA-like SCC/KA with malignant transformation was 33.3%. No regression was observed in either infundibular SCC or crateriform SCC arising from solar keratosis. Thus, KA is a distinct entity that should be distinguished from other types of SCC with crateriform architecture based on the high frequency of regression. The regression rate of 33.3% in KA-like SCC/KA with malignant transformation indicated that KA lesions with an SCC component still have the potential for regression. However, this result also indicated that KA is biologically unstable, and some KA tend to evolve into conventional SCC with a gradual loss of the capacity for the spontaneous regression. Infundibular SCC and crateriform SCC arising from solar keratosis are fundamentally different from KA, not only according to the histopathological findings but also based on the biological properties. © 2015 Japanese Dermatological Association.

  6. Herpes simplex virus detection in oral mucosa lesions in patients undergoing oncologic therapy.

    PubMed

    Sepúlveda Tebache, Ester; Brethauer Meier, Ursula; Jiménez Moraga, Marco; Morales Figueroa, Rocío; Rojas Castro, Jaime; Le Fort Canales, Patricia

    2003-01-01

    The presence of Herpes Simplex Virus (HSV) has been a frequent detection in gingivitis and ulcerations of oral mucosa in patients undergoing oncologic therapy. In these patients, lesions tend to show atypical clinical patterns, leading to misdiagnosis. To detect HSV, using an ELISA test, in oral lesions of patients under oncologic therapy, to determine localization of these lesions in the oral cavity, to relate their presence with the general diagnosis of the patient and to compare the test results with the previous clinical diagnosis of the lesions. Thirty lesions where examined in nineteen pediatric patients under oncologic therapy. Direct samples of all lesions were taken and an ELISA test for HSV type I and II was applied to them. General diagnosis of the patients was consigned, as well as localization of the lesions in the oral cavity and clinical diagnosis of them. A database was elaborated with all the information. 33% of lesions were positive to the test, most of them in patients with acute myeloid leukemia. Localization of lesions was not restricted to areas of mucosa attached to periosteum, but also in areas like the dorsum of the tongue. Positive predictivity of clinical diagnosis was 56,25% and negative predictive index was 92,86%. Sensitivity of the test was 90% and specificity was 65%. It is very important to corroborate clinical diagnosis of gingivitis and ulcerative lesions of the oral cavity of patients under oncologic therapy with laboratory tests, because of the atypical clinical presentation that can lead to misdiagnosis.

  7. Bennett lesions in baseball players detected by magnetic resonance imaging: assessment of association factors.

    PubMed

    Park, Jin-Young; Noh, Young-Min; Chung, Seok-Won; Moon, Sung-Gyn; Ha, Dae-Ho; Lee, Ki-Sun; Chung, Seok Won

    2016-05-01

    The purpose of this study was to evaluate the characteristics of Bennett lesions in baseball players compared with those without a Bennett lesion and to identify other possible factors associated with Bennett lesions on magnetic resonance imaging (MRI). We investigated 388 male baseball players with a career >1 year. Demographic factors and a routine physical examination, including glenohumeral internal rotation difference, scapular dyskinesis, and various pathologic changes, were reviewed on MRI to identify relative factors for Bennett lesions. Of the 388 patients evaluated, 125 (32.2%) were diagnosed with Bennett lesions of the shoulder. No significant differences were observed between the groups in demographic factors, physical examination results, visual analog scale score, American Shoulder and Elbow Surgeons score, or prevalence of concomitant diseases. However, players with Bennett lesions had played baseball longer than those without the lesions (P < .001). An association was found between Bennett lesions and the length of time that a patient with a Bennett lesion had played baseball. The prevalence of pathologic lesions detected on MRI and the physical examination results were not different between players with and without Bennett lesions. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  8. Risk factors of HIV-related oral lesions in adults.

    PubMed

    Petruzzi, Maria Noel Marzano Rodrigues; Cherubini, Karen; Salum, Fernanda Gonçalves; Figueiredo, Maria Antonia Zancanaro de

    2013-02-01

    To assess the risk factors in the occurrence of oral lesions in HIV-positive adults. A retrospective analytical-descriptive survey was conducted using the medical/dental records of 534 patients with oral lesions associated with HIV. The data were collected from five referral centers for managing HIV and associated comorbidities in the city of Porto Alegre, Southern Brazil, between 1996 and 2011. Using a standardized form, socio-demographic and clinical data were recorded. Exclusively and definitively diagnosed oral pathologies were included and classified according to ECC criteria on Oral Problems Related to HIV Infection. For data analysis cross-tabulations, Chi-squared tests and logistic regression models were used where appropriate. CD4+ counts lower than 350 cells/mm³ (p < 0.001), alcohol consumption (p = 0.011) and female gender (p = 0.031) were predisposing factors for oral candidiasis. The occurrence of hairy leukoplakia was independently associated with CD4+ counts below 500 cells/mm³, (p = 0.029) a viral load above 5,000 copies/mm³ (p = 0.003) and smoking (p = 0.005). Moderate and severe degrees of immunodeficiency and detectable viral loads were risk factors for the onset of oral lesions. Smoking and alcohol consumption also increased susceptibility to the development of opportunistic infections in HIV-positive adults from Porto Alegre, irrespective of the use of antiretroviral therapy.

  9. Detecting Proximal Secondary Caries Lesions: A Cost-effectiveness Analysis.

    PubMed

    Schwendicke, F; Brouwer, F; Paris, S; Stolpe, M

    2016-02-01

    When choosing detection methods for secondary caries lesions, dentists need to weigh sensitivity, allowing early initiation of retreatments to avoid lesion progression, against specificity, aiming to reduce risks of false-positive diagnoses and invasive overtreatments. We assessed the cost-effectiveness of different detection methods for proximal secondary lesions using Monte Carlo microsimulations. A vital permanent molar with an occlusal-proximal restoration was simulated over the lifetime of an initially 20-y-old. Three methods were compared: biannual tactile detection, radiographic detection every 2 y, and biannual laser fluorescence detection. Methods were employed either on their own or in pairwise combinations at sensitive and specific thresholds estimated with systematically collected data. A mixed public-private payer perspective in the context of German health care was applied. Effectiveness was calculated as years of tooth retention. Net-benefit analyses were used to evaluate cost-effectiveness acceptability at different willingness-to-pay thresholds. Radiographic detection verified by tactile assessment (both at specific thresholds) was least costly (mean, 1,060 euros) but had limited effectiveness (mean retention time, 50 y). The most effective but also more costly combination was laser fluorescence detection verified by radiography, again at specific thresholds (1157 euros, 53 y, acceptable if willingness to pay >32 euro/y). In the majority of simulations, not combining detection methods or applying them at sensitive thresholds was less effective and more costly. Net benefits were not greatly altered by applying different discounting rates or using different baseline prevalence of secondary lesions. Current detection methods for secondary lesions should best be used in combination, not on their own, at specific thresholds to avoid false-positive diagnoses leading to costly and invasive overtreatment. The relevant characteristics, such as predictive

  10. Echoplanar MR imaging for ultrafast detection of brain lesions.

    PubMed

    Patel, M R; Siewert, B; Klufas, R; Yousuf, N; Edelman, R R; Warach, S

    1999-08-01

    We retrospectively evaluated the use of echo-planar imaging for ultrafast detection of brain lesions. In our retrospective study, 61 patients were imaged with the following echo-planar sequences: single-shot proton density-weighted, single-shot T2-weighted, single-shot T2-weighted high-resolution, multishot proton density-weighted, and multishot T2-weighted. Lesions revealed in these patients ranged from 0.5 to 12.0 cm (mean, 3.7 cm) and were the result of tumor (n = 16), stroke (n = 21), demyelination (n = 18), and toxoplasmosis (n = 2). Four patients had scans with normal findings. Two neuroradiologists who were unaware of pertinent clinical data reviewed the images. The images were retrospectively compared with conventional spin-echo images for diagnosis, sensitivity of lesion detection, and qualitative criteria: subjective image quality, gray and white matter differentiation, lesion conspicuity, delineation of lesion borders, and artifacts. (Artifacts included those caused by motion, susceptibility, pulsation, and ghosting.) Quantitative criteria, including signal-to-noise and signal difference-to-noise measurements, were also evaluated in 40 lesions. Sensitivity for lesion detection was 97% for single-shot echo-planar T2-weighted MR images and 100% for multishot echo-planar T2-weighted MR images. Single-shot echo-planar proton density-weighted MR images had the highest signal-to-noise ratio (91.2+/-19.3). Echo-planar T2-weighted MR images had the highest signal difference-to-noise (33.8+/-22.9). Echo-planar sequences were superior to spin-echo sequences regarding motion and pulsation artifacts. Spin-echo sequences lacked susceptibility and ghosting artifacts, and were superior in lesion conspicuity and delineation of lesion borders. In this study, echo-planar sequences were as sensitive as conventional spin-echo imaging for the diagnostic assessment of lesions. Echo-planar sequences had a strikingly shorter acquisition time and substantially reduced motion and

  11. The impact of mammographic density and lesion location on detection

    NASA Astrophysics Data System (ADS)

    Al Mousa, Dana; Ryan, Elaine; Lee, Warwick; Nickson, Carolyn; Pietrzyk, Mariusz; Reed, Warren; Poulos, Ann; Li, Yanpeng; Brennan, Patrick

    2013-03-01

    The aim of this study is to examine the impact of breast density and lesion location on detection. A set of 55 mammographic images (23 abnormal images with 26 lesions and 32 normal images) were examined by 22 expert radiologists. The images were classified by an expert radiologist according to the Synoptic Breast Imaging Report of the National Breast Cancer Centre (NBCC) as having low mammographic density (D1<25% glandular and D2> 25-50% glandular) or high density (D3 51-75% glandular and D4> 75-glandular). The observers freely examined the images and located any malignancy using a 5-point confidence. Performance was defined using the following metrics: sensitivity, location sensitivity, specificity, receiver operating characteristic (ROC Az) curves and jackknife free-response receiver operator characteristics (JAFROC) figures of merit. Significant increases in sensitivity (p= 0.0174) and ROC (p=0.0001) values were noted for the higher density compared with lower density images according to NBCC classification. No differences were seen in radiologists' performance between lesions within or outside the fibroglandular region. In conclusion, analysis of our data suggests that radiologists scored higher using traditional metrics in higher mammographic density images without any improvement in lesion localisation. Lesion location whether within or outside the fibroglandular region appeared to have no impact on detection abilities suggesting that if a masking effect is present the impact is minimal. Eye-tracking analyses are ongoing.

  12. Skin lesion image segmentation using Delaunay Triangulation for melanoma detection.

    PubMed

    Pennisi, Andrea; Bloisi, Domenico D; Nardi, Daniele; Giampetruzzi, Anna Rita; Mondino, Chiara; Facchiano, Antonio

    2016-09-01

    Developing automatic diagnostic tools for the early detection of skin cancer lesions in dermoscopic images can help to reduce melanoma-induced mortality. Image segmentation is a key step in the automated skin lesion diagnosis pipeline. In this paper, a fast and fully-automatic algorithm for skin lesion segmentation in dermoscopic images is presented. Delaunay Triangulation is used to extract a binary mask of the lesion region, without the need of any training stage. A quantitative experimental evaluation has been conducted on a publicly available database, by taking into account six well-known state-of-the-art segmentation methods for comparison. The results of the experimental analysis demonstrate that the proposed approach is highly accurate when dealing with benign lesions, while the segmentation accuracy significantly decreases when melanoma images are processed. This behavior led us to consider geometrical and color features extracted from the binary masks generated by our algorithm for classification, achieving promising results for melanoma detection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Lesion detection using Gabor-based saliency field mapping

    NASA Astrophysics Data System (ADS)

    Macenko, Marc; Luo, Rutao; Celenk, Mehmet; Ma, Limin; Zhou, Qiang

    2007-03-01

    In this paper, we present a method that detects lesions in two-dimensional (2D) cross-sectional brain images. By calculating the major and minor axes of the brain, we calculate an estimate of the background, without any a priori information, to use in inverse filtering. Shape saliency computed by a Gabor filter bank is used to further refine the results of the inverse filtering. The proposed algorithm was tested on different images of "The Whole Brain Atlas" database. The experimental results have produced 93% classification accuracy in processing 100 arbitrary images, representing different kinds of brain lesion.

  14. Automatic white matter lesion segmentation using an adaptive outlier detection method.

    PubMed

    Ong, Kok Haur; Ramachandram, Dhanesh; Mandava, Rajeswari; Shuaib, Ibrahim Lutfi

    2012-07-01

    White matter (WM) lesions are diffuse WM abnormalities that appear as hyperintense (bright) regions in cranial magnetic resonance imaging (MRI). WM lesions are often observed in older populations and are important indicators of stroke, multiple sclerosis, dementia and other brain-related disorders. In this paper, a new automated method for WM lesions segmentation is presented. In the proposed method, the presence of WM lesions is detected as outliers in the intensity distribution of the fluid-attenuated inversion recovery (FLAIR) MR images using an adaptive outlier detection approach. Outliers are detected using a novel adaptive trimmed mean algorithm and box-whisker plot. In addition, pre- and postprocessing steps are implemented to reduce false positives attributed to MRI artifacts commonly observed in FLAIR sequences. The approach is validated using the cranial MRI sequences of 38 subjects. A significant correlation (R=0.9641, P value=3.12×10(-3)) is observed between the automated approach and manual segmentation by radiologist. The accuracy of the proposed approach was further validated by comparing the lesion volumes computed using the automated approach and lesions manually segmented by an expert radiologist. Finally, the proposed approach is compared against leading lesion segmentation algorithms using a benchmark dataset.

  15. [Retinal image analysis to detect lesions associated with diabetic retinopathy].

    PubMed

    Sánchez Gutiérrez, C I; López Gálvez, M I; Hornero Sánchez, R; Poza Crespo, J

    2004-12-01

    Diabetic retinopathy is a leading cause of vision loss in developed countries. Regular diabetic retinal eye screenings are needed to detect early signs of retinopathy, so that appropriate treatments can be rendered to prevent blindness. Digital imaging is becoming available as a means of screening for diabetic retinopathy. However, with the large number of patients undergoing screenings, medical professionals require a tremendous amount of time and effort in order to analyse and diagnose the fundus photographs. Our aim is to develop an automatic algorithm using digital image analysis for detecting these early lesions from retinal images. An automatic method to detect hard exudates, a lesion associated with diabetic retinopathy, is proposed. The algorithm is based on their colour, using a statistical classification, and their sharp edges, applying an edge detector, to localise them. A sensitivity of 79.62% with a mean number of 3 false positives per image is obtained in a database of 20 retinal images with variable colour, brightness and quality. It can also be seen that the number of the false negative cases increases when the hard exudates were very close to the vessel tree. The long term goal of the project is to automate the screening for diabetic retinopathy with retinal images. We have described the preliminary development of a tool to provide automatic analysis of digital fundus photographs to localise hard exudates. Future work will address the issue of improving the obtained results and also will focus on detecting other lesions.

  16. Detection of white matter lesions in cerebral small vessel disease

    NASA Astrophysics Data System (ADS)

    Riad, Medhat M.; Platel, Bram; de Leeuw, Frank-Erik; Karssemeijer, Nico

    2013-02-01

    White matter lesions (WML) are diffuse white matter abnormalities commonly found in older subjects and are important indicators of stroke, multiple sclerosis, dementia and other disorders. We present an automated WML detection method and evaluate it on a dataset of small vessel disease (SVD) patients. In early SVD, small WMLs are expected to be of importance for the prediction of disease progression. Commonly used WML segmentation methods tend to ignore small WMLs and are mostly validated on the basis of total lesion load or a Dice coefficient for all detected WMLs. Therefore, in this paper, we present a method that is designed to detect individual lesions, large or small, and we validate the detection performance of our system with FROC (free-response ROC) analysis. For the automated detection, we use supervised classification making use of multimodal voxel based features from different magnetic resonance imaging (MRI) sequences, including intensities, tissue probabilities, voxel locations and distances, neighborhood textures and others. After preprocessing, including co-registration, brain extraction, bias correction, intensity normalization, and nonlinear registration, ventricle segmentation is performed and features are calculated for each brain voxel. A gentle-boost classifier is trained using these features from 50 manually annotated subjects to give each voxel a probability of being a lesion voxel. We perform ROC analysis to illustrate the benefits of using additional features to the commonly used voxel intensities; significantly increasing the area under the curve (Az) from 0.81 to 0.96 (p<0.05). We perform the FROC analysis by testing our classifier on 50 previously unseen subjects and compare the results with manual annotations performed by two experts. Using the first annotator results as our reference, the second annotator performs at a sensitivity of 0.90 with an average of 41 false positives per subject while our automated method reached the same

  17. Detection of lesions in dysplastic Barrett's esophagus by community and expert endoscopists.

    PubMed

    Schölvinck, Dirk W; van der Meulen, Kim; Bergman, Jacques J G H M; Weusten, Bas L A M

    2017-02-01

    Background and aims Endoscopic treatment of Barrett's esophagus (BE) consists of endoscopic resection of visible lesions followed by radiofrequency ablation (RFA) for any remaining flat BE. Because RFA is only justified in flat BE, detection of neoplastic lesions (high grade dysplasia [HGD] and early adenocarcinoma [EAC]) is crucial. We hypothesized that the detection of visible lesions containing HGD or EAC would be superior in BE expert centers compared with community hospitals, thereby supporting centralization of therapy for BE-related neoplasia. Methods Patients referred with histologically proven HGD or EAC to two Dutch BE expert centers were included. Referral letters, and endoscopy and pathology reports were reviewed for the description of the BE, presence of lesions, and histopathological analysis of target and random tissue sampling. Primary outcome was the endoscopic detection rate of lesions containing histopathologically proven neoplasia (HGD and/or EAC) in community and expert centers. Results There were 198 patients referred from 37 community hospitals (median referral time 55 days [interquartile range 33 - 85]). Detection rates for visible lesions were 60 % in community centers (75 % in patients with a biopsy diagnosis of EAC, 47 % in HGD) and 87 % in expert centers (98 % in EAC, 75 % in HGD); P < 0.001. Even with HGD/EAC on random biopsies from the index endoscopy, the yield at repeat endoscopy was < 50 % in community hospitals. In 79 patients referred solely because of random biopsy results, a lesion requiring endoscopic resection or surgery was found in 76 % by the expert endoscopists. Conclusions Endoscopists at community hospitals detect neoplastic lesions at a significantly lower rate. These data support the value of BE expert centers for work-up and further treatment of BE.

  18. Brain lesion detection in MRI with fuzzy and geostatistical models.

    PubMed

    Pham, Tuan D

    2010-01-01

    Automated image detection of white matter changes of the brain is essentially helpful in providing a quantitative measure for studying the association of white matter lesions with other types of biomedical data. Such study allows the possibility of several medical hypothesis validations which lead to therapeutic treatment and prevention. This paper presents a new clustering-based segmentation approach for detecting white matter changes in magnetic resonance imaging with particular reference to cognitive decline in the elderly. The proposed method is formulated using the principles of fuzzy c-means algorithm and geostatistics.

  19. Bright Retinal Lesions Detection using Colour Fundus Images Containing Reflective Features

    SciTech Connect

    Giancardo, Luca; Karnowski, Thomas Paul; Chaum, Edward; Meriaudeau, Fabrice; Tobin Jr, Kenneth William; Li, Yaquin

    2009-01-01

    In the last years the research community has developed many techniques to detect and diagnose diabetic retinopathy with retinal fundus images. This is a necessary step for the implementation of a large scale screening effort in rural areas where ophthalmologists are not available. In the United States of America, the incidence of diabetes is worryingly increasing among the young population. Retina fundus images of patients younger than 20 years old present a high amount of reflection due to the Nerve Fibre Layer (NFL), the younger the patient the more these reflections are visible. To our knowledge we are not aware of algorithms able to explicitly deal with this type of reflection artefact. This paper presents a technique to detect bright lesions also in patients with a high degree of reflective NFL. First, the candidate bright lesions are detected using image equalization and relatively simple histogram analysis. Then, a classifier is trained using texture descriptor (Multi-scale Local Binary Patterns) and other features in order to remove the false positives in the lesion detection. Finally, the area of the lesions is used to diagnose diabetic retinopathy. Our database consists of 33 images from a telemedicine network currently developed. When determining moderate to high diabetic retinopathy using the bright lesions detected the algorithm achieves a sensitivity of 100% at a specificity of 100% using hold-one-out testing.

  20. Quantitative assessment of lesion detection accuracy, resolution, and reconstruction algorithms in neutron stimulated emission computed tomography.

    PubMed

    Lakshmanan, Manu N; Kapadia, Anuj J

    2012-07-01

    We present a quantitative analysis of the image quality obtained using filtered back-projection (FBP) with Ram-Lak filtering and maximum likelihood-expectation maximization (ML-EM)-with no post-reconstruction filtering in either case-in neutron stimulated emission computed tomography (NSECT) imaging using Monte Carlo simulations in the context of clinically relevant models of liver iron overload. The ratios of pixel intensities for several regions of interest and lesion shape detection using an active-contours segmentation algorithm are assessed for accuracy across different scanning configurations and reconstruction algorithms. The modulation transfer functions (MTFs) are also computed for the cases under study and are applied to determine a minimum detectable lesion spacing as a form of sensitivity analysis. The accuracy of NSECT imaging in measuring relative tissue concentration is presented for simulated clinical liver cases. When using the 15th iteration, ML-EM provides at least 25% better resolution than FBP and proves to be highly robust under low-signal high-noise conditions prevalent in NSECT. However, FBP gives more accurate lesion pixel intensity ratios and size estimates in some cases; due to advantages provided by both reconstruction algorithms, it is worth exploring the development of an algorithm that is a hybrid of the two. We also show that NSECT imaging can be used to accurately detect 3-cm lesions in backgrounds that are a significant fraction (one-quarter) of the concentration of the lesion, down to a 4-cm spacing between lesions.

  1. Detection of intaoral lesions using a fluorescence camera

    NASA Astrophysics Data System (ADS)

    Thoms, Michael

    2006-02-01

    Optical methods for the detection of carious lesions, calculus and plaque have the advantage of being minimally invasive. The use of endogeneous fluorescence markers like porphyrins could simplify the application of fluorescence techniques in the dental practice. It is known that porphyrins are produced by some of the bacterial species that are present in the oral cavity. Since porphyrins have an excitation band at about 400nm they have the potential to be used as fluorescent markers of locations in the oral cavity where the production of bacteria is out of the limits of healthy regions. Further, modern and efficient GaN-based semiconductor diodes emit light in this spectral range and thus make the implementation of fluorescence sensors with excitation at this wavelength easy. Carious lesions, calculus and plaque have been measured using a self build fluorescence camera using GaN-diodes for illumination at 405nm. Further, emission spectra under this excitation were recorded. For the latter purpose freshly extracted teeth were used. It has been found that already in the case of an initial carious lesion red porphyrin-fluorescence is emitted whereas it is absent in healthy enamel. In already brown coloured carious lesions the emission bands of porphyrin are present but the observed overall fluorescence intensity is lower, probably due to the absorption of the fluorescence by the carious defect itself. In dental calculus, dental plaque and subgingival concrements porphyrin originated luminescence was found as well. Since in these cases the emission spectra differ slightly it can be concluded that they originate from different types of porphyrins and thus also from different bacteria. These results show that this fluorescence technique can be a promising method to diagnose carious lesions, calculus and plaque.

  2. Automated detection of diabetic retinopathy lesions on ultrawidefield pseudocolour images.

    PubMed

    Wang, Kang; Jayadev, Chaitra; Nittala, Muneeswar G; Velaga, Swetha B; Ramachandra, Chaithanya A; Bhaskaranand, Malavika; Bhat, Sandeep; Solanki, Kaushal; Sadda, SriniVas R

    2017-09-19

    We examined the sensitivity and specificity of an automated algorithm for detecting referral-warranted diabetic retinopathy (DR) on Optos ultrawidefield (UWF) pseudocolour images. Patients with diabetes were recruited for UWF imaging. A total of 383 subjects (754 eyes) were enrolled. Nonproliferative DR graded to be moderate or higher on the 5-level International Clinical Diabetic Retinopathy (ICDR) severity scale was considered as grounds for referral. The software automatically detected DR lesions using the previously trained classifiers and classified each image in the test set as referral-warranted or not warranted. Sensitivity, specificity and the area under the receiver operating curve (AUROC) of the algorithm were computed. The automated algorithm achieved a 91.7%/90.3% sensitivity (95% CI 90.1-93.9/80.4-89.4) with a 50.0%/53.6% specificity (95% CI 31.7-72.8/36.5-71.4) for detecting referral-warranted retinopathy at the patient/eye levels, respectively; the AUROC was 0.873/0.851 (95% CI 0.819-0.922/0.804-0.894). Diabetic retinopathy (DR) lesions were detected from Optos pseudocolour UWF images using an automated algorithm. Images were classified as referral-warranted DR with a high degree of sensitivity and moderate specificity. Automated analysis of UWF images could be of value in DR screening programmes and could allow for more complete and accurate disease staging. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  3. Improved Detection of Microsatellite Instability in Early Colorectal Lesions

    PubMed Central

    Albrecht, Dawn M.; Grimes, Ian C.; Weiss, Jennifer M.; Matkowskyj, Kristina A.; Agni, Rashmi M.; Vyazunova, Irina; Clipson, Linda; Storts, Douglas R.; Thliveris, Andrew T.; Halberg, Richard B.

    2015-01-01

    Microsatellite instability (MSI) occurs in over 90% of Lynch syndrome cancers and is considered a hallmark of the disease. MSI is an early event in colon tumor development, but screening polyps for MSI remains controversial because of reduced sensitivity compared to more advanced neoplasms. To increase sensitivity, we investigated the use of a novel type of marker consisting of long mononucleotide repeat (LMR) tracts. Adenomas from 160 patients, ranging in age from 29–55 years old, were screened for MSI using the new markers and compared with current marker panels and immunohistochemistry standards. Overall, 15 tumors were scored as MSI-High using the LMRs compared to 9 for the NCI panel and 8 for the MSI Analysis System (Promega). This difference represents at least a 1.7-fold increase in detection of MSI-High lesions over currently available markers. Moreover, the number of MSI-positive markers per sample and the size of allelic changes were significantly greater with the LMRs (p = 0.001), which increased confidence in MSI classification. The overall sensitivity and specificity of the LMR panel for detection of mismatch repair deficient lesions were 100% and 96%, respectively. In comparison, the sensitivity and specificity of the MSI Analysis System were 67% and 100%; and for the NCI panel, 75% and 97%. The difference in sensitivity between the LMR panel and the other panels was statistically significant (p<0.001). The increased sensitivity for detection of MSI-High phenotype in early colorectal lesions with the new LMR markers indicates that MSI screening for the early detection of Lynch syndrome might be feasible. PMID:26252492

  4. Temporal Characteristics of Radiologists' and Novices' Lesion Detection in Viewing Medical Images Presented Rapidly and Sequentially

    PubMed Central

    Nakashima, Ryoichi; Komori, Yuya; Maeda, Eriko; Yoshikawa, Takeharu; Yokosawa, Kazuhiko

    2016-01-01

    Although viewing multiple stacks of medical images presented on a display is a relatively new but useful medical task, little is known about this task. Particularly, it is unclear how radiologists search for lesions in this type of image reading. When viewing cluttered and dynamic displays, continuous motion itself does not capture attention. Thus, it is effective for the target detection that observers' attention is captured by the onset signal of a suddenly appearing target among the continuously moving distractors (i.e., a passive viewing strategy). This can be applied to stack viewing tasks, because lesions often show up as transient signals in medical images which are sequentially presented simulating a dynamic and smoothly transforming image progression of organs. However, it is unclear whether observers can detect a target when the target appears at the beginning of a sequential presentation where the global apparent motion onset signal (i.e., signal of the initiation of the apparent motion by sequential presentation) occurs. We investigated the ability of radiologists to detect lesions during such tasks by comparing the performances of radiologists and novices. Results show that overall performance of radiologists is better than novices. Furthermore, the temporal locations of lesions in CT image sequences, i.e., when a lesion appears in an image sequence, does not affect the performance of radiologists, whereas it does affect the performance of novices. Results indicate that novices have greater difficulty in detecting a lesion appearing early than late in the image sequence. We suggest that radiologists have other mechanisms to detect lesions in medical images with little attention which novices do not have. This ability is critically important when viewing rapid sequential presentations of multiple CT images, such as stack viewing tasks. PMID:27774080

  5. 4D numerical observer for lesion detection in respiratory-gated PET

    PubMed Central

    Lorsakul, Auranuch; Li, Quanzheng; Trott, Cathryn M.; Hoog, Christopher; Petibon, Yoann; Ouyang, Jinsong; Laine, Andrew F.; El Fakhri, Georges

    2014-01-01

    compared to the conventional 3D approach applied on the nongated and motion-corrected images. Results: On average, the proposed 4D numerical observer improved the detection SNR by 48.6% (p < 0.005), whereas the 3D methods on motion-corrected images improved by 31.0% (p < 0.005) as compared to the nongated method. For all different conditions of the lesions, the relative SNR measurement (Gain = SNRObserved/SNRNongated) of the 4D method was significantly higher than one from the motion-corrected 3D method by 13.8% (p < 0.02), where Gain4D was 1.49 ± 0.21 and Gain3D was 1.31 ± 0.15. For the lesion with the highest amplitude of motion, the 4D numerical observer yielded the highest observer-performance improvement (176%). For the lesion undergoing the smallest motion amplitude, the 4D method provided superior lesion detectability compared with the 3D method, which provided a detection SNR close to the nongated method. The investigation on a structure of the 4D numerical observer showed that a Laguerre–Gaussian channel matrix with a volumetric 3D function yielded higher lesion-detection performance than one with a 2D-stack-channelized function, whereas a different kind of channels that have the ability to mimic the human visual system, i.e., difference-of-Gaussian, showed similar performance in detecting uniform and spherical lesions. The investigation of the detection performance when increasing noise levels yielded decreasing detection SNR by 27.6% and 41.5% for the nongated and gated methods, respectively. The investigation of lesion contrast and diameter showed that the proposed 4D observer preserved the linearity property of an optimal-linear observer while the motion was present. Furthermore, the investigation of the iteration and subset numbers of the OSEM algorithm demonstrated that these parameters had impact on the lesion detectability and the selection of the optimal parameters could provide the maximum lesion-detection performance. The proposed 4D numerical

  6. 4D numerical observer for lesion detection in respiratory-gated PET

    SciTech Connect

    Lorsakul, Auranuch; Li, Quanzheng; Ouyang, Jinsong; El Fakhri, Georges; Trott, Cathryn M.; Hoog, Christopher; Petibon, Yoann; Laine, Andrew F.

    2014-10-15

    compared to the conventional 3D approach applied on the nongated and motion-corrected images. Results: On average, the proposed 4D numerical observer improved the detection SNR by 48.6% (p < 0.005), whereas the 3D methods on motion-corrected images improved by 31.0% (p < 0.005) as compared to the nongated method. For all different conditions of the lesions, the relative SNR measurement (Gain = SNR{sub Observed}/SNR{sub Nongated}) of the 4D method was significantly higher than one from the motion-corrected 3D method by 13.8% (p < 0.02), where Gain{sub 4D} was 1.49 ± 0.21 and Gain{sub 3D} was 1.31 ± 0.15. For the lesion with the highest amplitude of motion, the 4D numerical observer yielded the highest observer-performance improvement (176%). For the lesion undergoing the smallest motion amplitude, the 4D method provided superior lesion detectability compared with the 3D method, which provided a detection SNR close to the nongated method. The investigation on a structure of the 4D numerical observer showed that a Laguerre–Gaussian channel matrix with a volumetric 3D function yielded higher lesion-detection performance than one with a 2D-stack-channelized function, whereas a different kind of channels that have the ability to mimic the human visual system, i.e., difference-of-Gaussian, showed similar performance in detecting uniform and spherical lesions. The investigation of the detection performance when increasing noise levels yielded decreasing detection SNR by 27.6% and 41.5% for the nongated and gated methods, respectively. The investigation of lesion contrast and diameter showed that the proposed 4D observer preserved the linearity property of an optimal-linear observer while the motion was present. Furthermore, the investigation of the iteration and subset numbers of the OSEM algorithm demonstrated that these parameters had impact on the lesion detectability and the selection of the optimal parameters could provide the maximum lesion-detection performance. The

  7. Modeling spatial relation in skin lesion images by the graph walk kernel.

    PubMed

    Situ, Ning; Wadhawan, Tarun; Yuan, Xiaojing; Zouridakis, George

    2010-01-01

    Early skin cancer detection with the help of dermoscopic images is becoming more and more important. Previous methods generally ignored the spatial relation of the pixels or regions inside the lesion. We propose to employ a graph representation of the skin lesion to model the spatial relation. We then use the graph walk kernel, a similarity measure between two graphs, to build a classifier based on support vector machines for melanoma detection. In experiments, we compare the sensitivities and specificities of models with and without spatial information. Experimental results show that the model with spatial information performs the best in both sensitivity and specificity. Statistical test indicates that the improvement is significant.

  8. Objective detection and localization of multiple sclerosis lesions on magnetic resonance brainstem images: validation with auditory evoked potentials.

    PubMed

    Stufflebeam, S M; Levine, R A; Gardner, J C; Fullerton, B C; Furst, M; Rosen, B R

    2000-01-01

    To develop an objective method for detecting multiple sclerosis (MS) brainstem lesions, magnetic resonance (MR) images (multiple planar, spin-echo, acquired in three planes of section) of sixteen MS patients and fourteen normal subjects were analyzed with an algorithm that detected regions with a relatively increased intensity on both a spin-echo image and a T2 image. To be considered a lesion, such regions had to overlap in at least two orthogonal planes. Using a digitized atlas of the human brainstem, the lesion locations were mapped with respect to the brainstem anatomy. This method was evaluated by comparing the location of MS lesions with the brainstem auditory evoked potentials obtained from these subjects. Brainstem lesions were detected in five MS patients; four had lesions impinging upon the auditory system and one did not. All four had abnormal evoked potentials. The fourteen normal subjects, the one MS patient with brainstem lesions outside the auditory pathway, and the eleven other MS patients with no brainstem lesions all had normal evoked potentials. The requirement that lesions be detected in at least two planes of section greatly improved the specificity of the algorithm. The consistency between the MR and brainstem auditory evoked potentials results supports the validity of this imaging analysis algorithm for objectively localizing brainstem lesions.

  9. Genital HPV infection and related lesions in men.

    PubMed

    Anic, Gabriella M; Giuliano, Anna R

    2011-10-01

    Human papillomavirus (HPV) is highly prevalent in men and there is an interest in further understanding the relationship between HPV infection and disease in men, including the development of genital warts, penile intraepithelial neoplasia and invasive penile carcinomas. Genital warts are caused by HPV 6/11 and are the most common clinical manifestation of HPV in men. Though they are benign and not associated with mortality, they are a source of psychosocial distress and physical discomfort. HPV infection can also develop into invasive penile carcinoma which is associated with morbidity and mortality. Approximately 40% of invasive penile carcinomas are attributable to HPV with HPV 16, 18, and 6/11 being the genotypes most commonly detected in penile tumors. Penile carcinomas of the basaloid and warty histologic subtypes are most likely to test positive for HPV. In addition to HPV infection, the risk factors most strongly associated with penile cancer are lack of neonatal circumcision, phimosis (the inability of uncircumcised men to fully retract the foreskin), and anogenital warts. Male vaccination with the quadrivalent HPV vaccine that protects against HPV 6/11/16/18 has been shown to significantly reduce HPV-associated anogenital infection and disease in men. If the quadrivalent vaccine is successfully disseminated to large segments of the young male population, there is the potential for substantial reduction in genital HPV infection and related lesions in men. Copyright © 2011. Published by Elsevier Inc.

  10. Lesion mapping of stroke-related erectile dysfunction.

    PubMed

    Winder, Klemens; Seifert, Frank; Köhrmann, Martin; Crodel, Carl; Kloska, Stephan; Dörfler, Arnd; Hösl, Katharina M; Schwab, Stefan; Hilz, Max J

    2017-06-01

    Acute ischaemic stroke in brain areas contributing to male sexual function may impair erectile function depending on the lesion site. This study intended to determine associations between stroke-related erectile dysfunction and cerebral ischaemic lesion sites using voxel-based lesion mapping. In 52 males (mean age 60.5 ± 10.5 years) with first-ever ischaemic strokes, we assessed erectile function after and retrospectively 3 months prior to the stroke using scores of the 5-item International Index of Erectile Function-5 questionnaire. We assessed cardiovascular risk factors and determined clinical stroke severity and infarct volumes as well as total brain volume by neuroimaging. We calculated correlations between patient age, clinical stroke severity, infarct volumes as well as brain volumes and the difference between erectile dysfunction scores before and after stroke. Moreover, we compared patient age, prevalence of cardiovascular risk factors, clinical stroke severity, infarct volumes and brain volumes of patients with unchanged and deteriorated erectile function after stroke. The infarcts were manually outlined and transformed into stereotaxic space. We determined the lesion overlap and performed subtraction analyses of lesions. In a voxel-based lesion analysis, the difference between erectile dysfunction scores before and after stroke was correlated with the lesion site using t-test statistics. Finally, we conducted a region of interest-based multivariate linear regression analysis that was adjusted for potential confounding factors including patient age, clinical stroke severity, imaging modality, lesion size and brain volume. In 32 patients (61.5%) erectile dysfunction scores declined after the stroke and therefore had stroke-related erectile dysfunction. Deterioration of erectile dysfunction scores was not associated with patient age, clinical stroke severity, infarct volume, brain volume, and cardiovascular risk factors. The voxel-wise subtraction analysis

  11. Potential of hybrid adaptive filtering in inflammatory lesion detection from capsule endoscopy images

    PubMed Central

    Charisis, Vasileios S; Hadjileontiadis, Leontios J

    2016-01-01

    A new feature extraction technique for the detection of lesions created from mucosal inflammations in Crohn’s disease, based on wireless capsule endoscopy (WCE) images processing is presented here. More specifically, a novel filtering process, namely Hybrid Adaptive Filtering (HAF), was developed for efficient extraction of lesion-related structural/textural characteristics from WCE images, by employing Genetic Algorithms to the Curvelet-based representation of images. Additionally, Differential Lacunarity (DLac) analysis was applied for feature extraction from the HAF-filtered images. The resulted scheme, namely HAF-DLac, incorporates support vector machines for robust lesion recognition performance. For the training and testing of HAF-DLac, an 800-image database was used, acquired from 13 patients who undertook WCE examinations, where the abnormal cases were grouped into mild and severe, according to the severity of the depicted lesion, for a more extensive evaluation of the performance. Experimental results, along with comparison with other related efforts, have shown that the HAF-DLac approach evidently outperforms them in the field of WCE image analysis for automated lesion detection, providing higher classification results, up to 93.8% (accuracy), 95.2% (sensitivity), 92.4% (specificity) and 92.6% (precision). The promising performance of HAF-DLac paves the way for a complete computer-aided diagnosis system that could support physicians’ clinical practice. PMID:27818583

  12. Potential of hybrid adaptive filtering in inflammatory lesion detection from capsule endoscopy images.

    PubMed

    Charisis, Vasileios S; Hadjileontiadis, Leontios J

    2016-10-21

    A new feature extraction technique for the detection of lesions created from mucosal inflammations in Crohn's disease, based on wireless capsule endoscopy (WCE) images processing is presented here. More specifically, a novel filtering process, namely Hybrid Adaptive Filtering (HAF), was developed for efficient extraction of lesion-related structural/textural characteristics from WCE images, by employing Genetic Algorithms to the Curvelet-based representation of images. Additionally, Differential Lacunarity (DLac) analysis was applied for feature extraction from the HAF-filtered images. The resulted scheme, namely HAF-DLac, incorporates support vector machines for robust lesion recognition performance. For the training and testing of HAF-DLac, an 800-image database was used, acquired from 13 patients who undertook WCE examinations, where the abnormal cases were grouped into mild and severe, according to the severity of the depicted lesion, for a more extensive evaluation of the performance. Experimental results, along with comparison with other related efforts, have shown that the HAF-DLac approach evidently outperforms them in the field of WCE image analysis for automated lesion detection, providing higher classification results, up to 93.8% (accuracy), 95.2% (sensitivity), 92.4% (specificity) and 92.6% (precision). The promising performance of HAF-DLac paves the way for a complete computer-aided diagnosis system that could support physicians' clinical practice.

  13. Molecular alterations in malignant blue nevi and related blue lesions.

    PubMed

    Yilmaz, Ismail; Gamsizkan, Mehmet; Sari, Sule Ozturk; Yaman, Banu; Demirkesen, Cuyan; Heper, Aylin; Calli, Aylin Orgen; Narli, Gizem; Kucukodaci, Zafer; Berber, Ufuk; Demirel, Dilaver; Akalin, Taner; Demiriz, Murat; Buyukbabani, Nesimi

    2015-12-01

    Malignant blue nevi (MBN) are extremely rare dermal melanocytic tumors that arise in association with atypical cellular blue nevi (ACBN), cellular blue nevi (CBN), common blue nevi (BN), or de novo. The frequency of BRAF, NRAS, and KIT mutations in malignant melanoma varies according to histological subtype and localization. These mutations are rarely observed in blue nevi, which have recently been shown to carry activating mutations in GNAQ/GNA11 genes. Only few small molecular studies of MBN have been published. The aim of the present study was to analyze in MBN and related blue lesions such as ACBN, CBN, and BN the prevalence of BRAF, NRAS, KIT, GNAQ, and GNA11 gene mutations and their association with clinicopathological features. We included in our study 12 MBN, 6 ACBN, 29 CBN, and 35 common BN diagnosed between 1996 and 2014. Sanger sequencing method was used for mutation analysis. Overall, GNAQ exon 5 mutation was the most frequent alteration (46 %), in 2 of 12 (17 %) MBN, 1 of 6 (17 %) ACBN, 22 of 29 (76 %) CBN, and 13 of 35 (37 %) common BN. BRAF V600E and GNA11 exon 5 mutations were respectively detected in 3 of 12 (25 %) and in 2 of 12 (17 %) MBN while none in ACBN, CBN, and common BN. None of the cases harbored NRAS exon 2/3, KIT exon 9/11/13/17/18, or GNAQ/GNA11 exon 4 mutations. GNAQ gene exon 5 mutations are rare in MBN and ACBN but frequent in CBN and common BN. Remarkably, BRAF V600E and GNA11 exon 5 mutations were only detected in MBN, whereas none were found in ACBN, CBN, or common BN. Our data contribute new elements to the limited data on molecular alterations in MBN.

  14. Detection of Lesions Underlying Intractable Epilepsy on T1-Weighted MRI as an Outlier Detection Problem

    PubMed Central

    El Azami, Meriem; Hammers, Alexander; Jung, Julien; Costes, Nicolas; Bouet, Romain; Lartizien, Carole

    2016-01-01

    Pattern recognition methods, such as computer aided diagnosis (CAD) systems, can help clinicians in their diagnosis by marking abnormal regions in an image. We propose a machine learning system based on a one-class support vector machine (OC-SVM) classifier for the detection of abnormalities in magnetic resonance images (MRI) applied to patients with intractable epilepsy. The system learns the features associated with healthy control subjects, allowing a voxelwise assessment of the deviation of a test subject pattern from the learned patterns. While any number of various features can be chosen and learned, here we focus on two texture parameters capturing image patterns associated with epileptogenic lesions on T1-weighted brain MRI e.g. heterotopia and blurred junction between the grey and white matter. The CAD output consists of patient specific 3D maps locating clusters of suspicious voxels ranked by size and degree of deviation from control patterns. System performance was evaluated using realistic simulations of challenging detection tasks as well as clinical data of 77 healthy control subjects and of eleven patients (13 lesions). It was compared to that of a mass univariate statistical parametric mapping (SPM) single subject analysis based on the same set of features. For all simulations, OC-SVM yielded significantly higher values of the area under the ROC curve (AUC) and higher sensitivity at low false positive rate. For the clinical data, both OC-SVM and SPM successfully detected 100% of the lesions in the MRI positive cases (3/13). For the MRI negative cases (10/13), OC-SVM detected 7/10 lesions and SPM analysis detected 5/10 lesions. In all experiments, OC-SVM produced fewer false positive detections than SPM. OC-SVM may be a versatile system for unbiased lesion detection. PMID:27603778

  15. Detection of Lesions Underlying Intractable Epilepsy on T1-Weighted MRI as an Outlier Detection Problem.

    PubMed

    El Azami, Meriem; Hammers, Alexander; Jung, Julien; Costes, Nicolas; Bouet, Romain; Lartizien, Carole

    2016-01-01

    Pattern recognition methods, such as computer aided diagnosis (CAD) systems, can help clinicians in their diagnosis by marking abnormal regions in an image. We propose a machine learning system based on a one-class support vector machine (OC-SVM) classifier for the detection of abnormalities in magnetic resonance images (MRI) applied to patients with intractable epilepsy. The system learns the features associated with healthy control subjects, allowing a voxelwise assessment of the deviation of a test subject pattern from the learned patterns. While any number of various features can be chosen and learned, here we focus on two texture parameters capturing image patterns associated with epileptogenic lesions on T1-weighted brain MRI e.g. heterotopia and blurred junction between the grey and white matter. The CAD output consists of patient specific 3D maps locating clusters of suspicious voxels ranked by size and degree of deviation from control patterns. System performance was evaluated using realistic simulations of challenging detection tasks as well as clinical data of 77 healthy control subjects and of eleven patients (13 lesions). It was compared to that of a mass univariate statistical parametric mapping (SPM) single subject analysis based on the same set of features. For all simulations, OC-SVM yielded significantly higher values of the area under the ROC curve (AUC) and higher sensitivity at low false positive rate. For the clinical data, both OC-SVM and SPM successfully detected 100% of the lesions in the MRI positive cases (3/13). For the MRI negative cases (10/13), OC-SVM detected 7/10 lesions and SPM analysis detected 5/10 lesions. In all experiments, OC-SVM produced fewer false positive detections than SPM. OC-SVM may be a versatile system for unbiased lesion detection.

  16. Relations between exposure to arsenic, skin lesions, and glucosuria

    PubMed Central

    Rahman, M.; Tondel, M.; Chowdhury, I. A.; Axelson, O.

    1999-01-01

    OBJECTIVES: Exposure to arsenic causes keratosis, hyperpigmentation, and hypopigmentation and seemingly also diabetes mellitus, at least in subjects with skin lesions. Here we evaluate the relations of arsenical skin lesions and glucosuria as a proxy for diabetes mellitus. METHODS: Through existing measurements of arsenic in drinking water in Bangladesh, wells with and without arsenic contamination were identified. Based on a questionnaire, 1595 subjects > or = 30 years of age were interviewed; 1481 had a history of drinking water contaminated with arsenic whereas 114 had not. Time weighted mean arsenic concentrations and mg-years/l of exposure to arsenic were estimated based on the history of consumption of well water and current arsenic concentrations. Urine samples from the study subjects were tested by means of a glucometric strip. People with positive tests were considered to be cases of glucosuria. RESULTS: A total of 430 (29%) of the exposed people were found to have skin lesions. Corresponding to drinking water with < 0.5, 0.5-1.0, and > 1.0 mg/l of arsenic, and with the 114 unexposed subjects as the reference, the prevalence ratios for glucosuria, as adjusted for age and sex, were 0.8, 1.4, and 1.4 for those without skin lesions, and 1.1, 2.2, and 2.6 for those with skin lesions. Taking exposure as < 1.0, 1.0-5.0, > 5.0-10.0 and > 10.0 mg- years/l of exposure to arsenic the prevalence ratios, similarly adjusted, were 0.4, 0.9, 1.2, and 1.7 for those without and 0.8, 1.7, 2.1, and 2.9 for those with skin lesions. All series of risk estimates were significant for trend, (p < 0.01). CONCLUSIONS: The results suggest that skin lesions and diabetes mellitus, as here indicated by glucosuria, are largely independent effects of exposure to arsenic although glucosuria had some tendency to be associated with skin lesions. Importantly, however, glucosuria (diabetes mellitus) may occur independently of skin lesions.   PMID:10450246

  17. Density-based parallel skin lesion border detection with webCL

    PubMed Central

    2015-01-01

    Background Dermoscopy is a highly effective and noninvasive imaging technique used in diagnosis of melanoma and other pigmented skin lesions. Many aspects of the lesion under consideration are defined in relation to the lesion border. This makes border detection one of the most important steps in dermoscopic image analysis. In current practice, dermatologists often delineate borders through a hand drawn representation based upon visual inspection. Due to the subjective nature of this technique, intra- and inter-observer variations are common. Because of this, the automated assessment of lesion borders in dermoscopic images has become an important area of study. Methods Fast density based skin lesion border detection method has been implemented in parallel with a new parallel technology called WebCL. WebCL utilizes client side computing capabilities to use available hardware resources such as multi cores and GPUs. Developed WebCL-parallel density based skin lesion border detection method runs efficiently from internet browsers. Results Previous research indicates that one of the highest accuracy rates can be achieved using density based clustering techniques for skin lesion border detection. While these algorithms do have unfavorable time complexities, this effect could be mitigated when implemented in parallel. In this study, density based clustering technique for skin lesion border detection is parallelized and redesigned to run very efficiently on the heterogeneous platforms (e.g. tablets, SmartPhones, multi-core CPUs, GPUs, and fully-integrated Accelerated Processing Units) by transforming the technique into a series of independent concurrent operations. Heterogeneous computing is adopted to support accessibility, portability and multi-device use in the clinical settings. For this, we used WebCL, an emerging technology that enables a HTML5 Web browser to execute code in parallel for heterogeneous platforms. We depicted WebCL and our parallel algorithm design. In

  18. Density-based parallel skin lesion border detection with webCL.

    PubMed

    Lemon, James; Kockara, Sinan; Halic, Tansel; Mete, Mutlu

    2015-01-01

    Dermoscopy is a highly effective and noninvasive imaging technique used in diagnosis of melanoma and other pigmented skin lesions. Many aspects of the lesion under consideration are defined in relation to the lesion border. This makes border detection one of the most important steps in dermoscopic image analysis. In current practice, dermatologists often delineate borders through a hand drawn representation based upon visual inspection. Due to the subjective nature of this technique, intra- and inter-observer variations are common. Because of this, the automated assessment of lesion borders in dermoscopic images has become an important area of study. Fast density based skin lesion border detection method has been implemented in parallel with a new parallel technology called WebCL. WebCL utilizes client side computing capabilities to use available hardware resources such as multi cores and GPUs. Developed WebCL-parallel density based skin lesion border detection method runs efficiently from internet browsers. Previous research indicates that one of the highest accuracy rates can be achieved using density based clustering techniques for skin lesion border detection. While these algorithms do have unfavorable time complexities, this effect could be mitigated when implemented in parallel. In this study, density based clustering technique for skin lesion border detection is parallelized and redesigned to run very efficiently on the heterogeneous platforms (e.g. tablets, SmartPhones, multi-core CPUs, GPUs, and fully-integrated Accelerated Processing Units) by transforming the technique into a series of independent concurrent operations. Heterogeneous computing is adopted to support accessibility, portability and multi-device use in the clinical settings. For this, we used WebCL, an emerging technology that enables a HTML5 Web browser to execute code in parallel for heterogeneous platforms. We depicted WebCL and our parallel algorithm design. In addition, we tested

  19. Automated detection of dark and bright lesions in retinal images for early detection of diabetic retinopathy.

    PubMed

    Akram, Usman M; Khan, Shoab A

    2012-10-01

    There is an ever-increasing interest in the development of automatic medical diagnosis systems due to the advancement in computing technology and also to improve the service by medical community. The knowledge about health and disease is required for reliable and accurate medical diagnosis. Diabetic Retinopathy (DR) is one of the most common causes of blindness and it can be prevented if detected and treated early. DR has different signs and the most distinctive are microaneurysm and haemorrhage which are dark lesions and hard exudates and cotton wool spots which are bright lesions. Location and structure of blood vessels and optic disk play important role in accurate detection and classification of dark and bright lesions for early detection of DR. In this article, we propose a computer aided system for the early detection of DR. The article presents algorithms for retinal image preprocessing, blood vessel enhancement and segmentation and optic disk localization and detection which eventually lead to detection of different DR lesions using proposed hybrid fuzzy classifier. The developed methods are tested on four different publicly available databases. The presented methods are compared with recently published methods and the results show that presented methods outperform all others.

  20. Improving lesion detectability in PET imaging with a penalized likelihood reconstruction algorithm

    NASA Astrophysics Data System (ADS)

    Wangerin, Kristen A.; Ahn, Sangtae; Ross, Steven G.; Kinahan, Paul E.; Manjeshwar, Ravindra M.

    2015-03-01

    Ordered Subset Expectation Maximization (OSEM) is currently the most widely used image reconstruction algorithm for clinical PET. However, OSEM does not necessarily provide optimal image quality, and a number of alternative algorithms have been explored. We have recently shown that a penalized likelihood image reconstruction algorithm using the relative difference penalty, block sequential regularized expectation maximization (BSREM), achieves more accurate lesion quantitation than OSEM, and importantly, maintains acceptable visual image quality in clinical wholebody PET. The goal of this work was to evaluate lesion detectability with BSREM versus OSEM. We performed a twoalternative forced choice study using 81 patient datasets with lesions of varying contrast inserted into the liver and lung. At matched imaging noise, BSREM and OSEM showed equivalent detectability in the lungs, and BSREM outperformed OSEM in the liver. These results suggest that BSREM provides not only improved quantitation and clinically acceptable visual image quality as previously shown but also improved lesion detectability compared to OSEM. We then modeled this detectability study, applying both nonprewhitening (NPW) and channelized Hotelling (CHO) model observers to the reconstructed images. The CHO model observer showed good agreement with the human observers, suggesting that we can apply this model to future studies with varying simulation and reconstruction parameters.

  1. [Demand for abortion. Detection of cervical cancer and precancerous lesions].

    PubMed

    Benmoura, D

    1994-03-01

    Eighteen years of experience with cervical screening in the Center for Social Gynecology in Marseilles has demonstrated the existence of a group at high risk of cervical dysplasia. Its characteristics are early initiation of sexual activity, sexually transmitted disease, sexual promiscuity, and an unfavorable socioeconomic environment. Precancerous lesions are sometimes observed before the age of 18. Pap tests are done during preabortion consultations at the Center except in very young patients, those who are too emotionally distressed, and those with inflammations from vaginitis. The test may be done before the abortion because in the first trimester the cells do not yet show changes that would interfere with interpretation of the Pap smear. Bleeding after the abortion interferes with reading the slide. Results of 405 Pap tests conducted during a reference period from August 1992 to July 1993 among women seeking abortions at the Center for Social Gynecology were compared to those of 1601 women undergoing gynecological examinations at two other centers. Among patients at the Center for Social Gynecology and the other two centers respectively, 3.5% and 1.4% were diagnosed with condylomas, 1.5% and 1.2% with dysplasia, and 1.25% and 0.5% with condylomas and dysplasia. During the reference period, only 20% of women were screened. The number of lesions detected suggests that a higher proportion of women should be screened in this population of women often lacking regular medical care.

  2. Hippocampal lesion prevents spatial relational learning in adult macaque monkeys.

    PubMed

    Lavenex, Pamela Banta; Amaral, David G; Lavenex, Pierre

    2006-04-26

    The role of the hippocampus in spatial learning and memory has been extensively studied in rodents. Comparable studies in nonhuman primates, however, are few, and findings are often contradictory. This may be attributable to the failure to distinguish between allocentric and egocentric spatial representations in experimental designs. For this experiment, six adult monkeys received bilateral hippocampal ibotenic acid lesions, and six control subjects underwent sham surgery. Freely moving monkeys then foraged for food located in two arrays of three distinct locations among 18 locations distributed in an open-field arena. Multiple goals and four pseudorandomly chosen entrance points precluded the monkeys' ability to rely on an egocentric strategy to identify food locations. Monkeys were tested in two conditions. First, local visual cues marked the food locations. Second, no local cues marked the food locations, so that monkeys had to rely on an allocentric (spatial relational) representation of the environment to discriminate these locations. Both hippocampal-lesioned and control monkeys discriminated the food locations in the presence of local cues. However, in the absence of local cues, control subjects discriminated the food locations, whereas hippocampal-lesioned monkeys were unable to do so. Interestingly, histological analysis of the brain of one control monkey whose behavior was identical to that of the experimentally lesioned animals revealed a bilateral ischemic lesion restricted to the hippocampus. These findings demonstrate that the adult monkey hippocampal formation is critical for the establishment or use of allocentric spatial representations and that selective damage of the hippocampus prevents spatial relational learning in adult nonhuman primates.

  3. Comparative performance of multiview stereoscopic and mammographic display modalities for breast lesion detection

    SciTech Connect

    Webb, Lincoln J.; Samei, Ehsan; Lo, Joseph Y.; Baker, Jay A.; Ghate, Sujata V.; Kim, Connie; Soo, Mary Scott; Walsh, Ruth

    2011-04-15

    Purpose: Mammography is known to be one of the most difficult radiographic exams to interpret. Mammography has important limitations, including the superposition of normal tissue that can obscure a mass, chance alignment of normal tissue to mimic a true lesion and the inability to derive volumetric information. It has been shown that stereomammography can overcome these deficiencies by showing that layers of normal tissue lay at different depths. If standard stereomammography (i.e., a single stereoscopic pair consisting of two projection images) can significantly improve lesion detection, how will multiview stereoscopy (MVS), where many projection images are used, compare to mammography? The aim of this study was to assess the relative performance of MVS compared to mammography for breast mass detection. Methods: The MVS image sets consisted of the 25 raw projection images acquired over an arc of approximately 45 deg. using a Siemens prototype breast tomosynthesis system. The mammograms were acquired using a commercial Siemens FFDM system. The raw data were taken from both of these systems for 27 cases and realistic simulated mass lesions were added to duplicates of the 27 images at the same local contrast. The images with lesions (27 mammography and 27 MVS) and the images without lesions (27 mammography and 27 MVS) were then postprocessed to provide comparable and representative image appearance across the two modalities. All 108 image sets were shown to five full-time breast imaging radiologists in random order on a state-of-the-art stereoscopic display. The observers were asked to give a confidence rating for each image (0 for lesion definitely not present, 100 for lesion definitely present). The ratings were then compiled and processed using ROC and variance analysis. Results: The mean AUC for the five observers was 0.614{+-}0.055 for mammography and 0.778{+-}0.052 for multiview stereoscopy. The difference of 0.164{+-}0.065 was statistically significant with a

  4. [Lesions Detected in Six Spanish Colorectal Cancer Screening Population Based Programmes. CRIBEA Project. Spain].

    PubMed

    Portillo Villares, Isabel; Arana-Arri, Eunate; Idigoras Rubio, Isabel; Espinás Piñol, Josep Alfons; Pérez Riquelme, Francisco; de la Vega Prieto, Mariola; González Aledo, Alvaro; Oceja Setien, Elena; Vanaclocha Espi, Mercedes; Ibáñez Cabanell, Josefa; Salas Trejo, Dolores

    2017-02-20

    In this study, the results of six Colorectal Cancer Screening Population Programmes are shown (Catalonia, Valence, Murcia, Cantabria, the Basque Country and the Canary Islands collected between 2005 and 2012. These programmes use the faeces occult blood test (FOBt) biennial. Objective: To determine and compare the results of lesions detected by the programmes, participation, sex, age and test used. Retrospective cohort study based on people invited, aged between 50-74 years, in at least a complete round. Lesions considered: Advanced Adenomas (AA), Colorectal Invasive Cancer (CRC) and both of them, known as Advanced Neoplasia (AN). Logistic Regression and time trends are used. 1,995,719 of invitations registered, with an average participation-rate of 46.7%. 21,228 Advanced Neoplasias (2,813 CRC and 18,415 AA). Differences in detection rates observed between programmes (varying from 15.1‰ to 35.8‰ between participants). Participation rates were related to lesions' detection rates (OR 1.25 in 40-60% of participation). . Inmunochemical qualitative test showed an OR of 4.79 and quantitative test an OR of 7.30 over the guaiac test. Men showed an OR of 2.73 with respect to women. In 2012 the Advanced Neoplasia rate for women and men was 33.1 and 14.2 by 1,000 participants. The test used was the most important factor for detecting lesions. Time trends showed an increase in detected lesions caused by the change of the type of test in 2010.

  5. Significance of incidentally detected subcentimeter enhancing lesions on preoperative breast MRI: role of second-look ultrasound in lesion detection and management.

    PubMed

    Nam, Se Jin; Kim, Eun-Kyung; Kim, Min Jung; Moon, Hee Jung; Yoon, Jung Hyun

    2015-03-01

    OBJECTIVE. The purpose of this article is to evaluate the clinical significance of subcentimeter enhancing lesions incidentally detected on preoperative breast MRI in patients with breast cancer and the role of second-look ultrasound in lesion detection and characterization. MATERIALS AND METHODS. From January 2010 through December 2010, 180 lesions measuring less than 10 mm incidentally detected on MRI in 108 women with second-look ultrasound examinations were included (mean patient age, 47.9 years; mean [± SD] lesion size, 5.56 ± 1.64 mm). Seventy-two (40.0%) lesions were smaller than 5 mm, and 108 (60.0%) were 5 mm or larger. Of the 180 lesions, 103 (57.2%) had been biopsied or excised by localization, and 77 (42.8%) with benign ultrasound features had been followed with ultrasound for at least 2 years. Clinical and imaging features were recorded for analysis. RESULTS. Of the 180 enhancing lesions detected on MRI, 14 (7.8%) were malignant and 166 (92.2%) were benign. The malignancy rate of lesions 5 mm or larger was higher than that for lesions smaller than 5 mm (10.2% vs 4.2%), without statistical significance (p = 0.344). The washout enhancement pattern was statistically significantly associated with malignancy (p = 0.032). Although malignant ultrasound features such as nonparallel orientation were more common in malignant lesions, most malignancies had benign features, including oval shape, parallel orientation, and circumscribed margins, with BI-RADS category 4a (n = 12; 85.8%) as the final assessment. CONCLUSION. Second-look ultrasound is a feasible method for evaluating MRI-detected subcentimeter sized lesions in preoperative assessment of patients with breast cancer. A lower threshold should be applied with consideration of MRI features in deciding whether to biopsy or excise these lesions.

  6. Comparison of radiography and ultrasonography to detect osteochondrosis lesions in the tarsocrural joint: a prospective study.

    PubMed

    Relave, F; Meulyzer, M; Alexander, K; Beauchamp, G; Marcoux, M

    2009-01-01

    Lesions located on the medial malleolus of the tarsocrural joint can be difficult to image radiographically. Ultrasonography allows evaluation of articular cartilage and subchondral bone. To compare dorso30 degrees lateral-plantaromedial-oblique (DL-PIMO) and dorso45 degrees views to detect lesions on the medial malleolus, to validate the use of ultrasonography to show lesions in the tarsocrural joint and to compare its sensitivity to radiography. Tarsocrural joints (n=111) with osteochondrosis were evaluated ultrasonographically and radiographically prior to arthroscopic lesion debridement. A complete radiographic examination was made and the best view to detect each lesion recorded. Longitudinal and transverse ultrasonography of the dorsal aspect of the joint was performed and the best scan plane to image each lesion recorded. There were 94 joints with lesions on the distal intermediate ridge of tibia, 24 with lesions on the medial malleolus, and 4 with lesions on the lateral trochlear ridge. The sensitivity of radiography to detect lesions on the medial malleolus and distal intermediate ridge of tibia was 71 and 96%, respectively. Eighty-two percent of lesions on the medial malleolus were better imaged on dorso30 degrees view. The sensitivity of ultrasonography to detect lesions on the medial malleolus and distal intermediate ridge of tibia was 83 and 98%, respectively. Ultrasonography was significantly more sensitive than radiography to detect lesions on the medial malleolus and distal intermediate ridge of tibia. Dorso30 degrees lateral-plantaromedial-oblique view was the best to image lesions on the medial malleolus. Ultrasonography was a valuable diagnostic tool to diagnose lesions in the tarsocrural joint and was more sensitive than radiography for lesions located on the medial malleolus and distal intermediate ridge of tibia. Radiographic examination should include a dorso30 degrees view for detection of lesions on the medial malleolus and ultrasonography

  7. Perfusion computed tomography relative threshold values in definition of acute stroke lesions.

    PubMed

    Maija, Radzina; Gaida, Krumina; Karlis, Kupcs; Evija, Miglane

    2013-01-01

    Perfusion computed tomography (CT) is a relatively new technique that allows fast evaluation of cerebral hemodynamics by providing perfusion maps and gives confirmation of perfusion deficits in ischemic areas. Some controversies exist regarding accuracy of quantitative detection of tissue viability: penumbra (tissue at risk) or core (necrosis). To define brain tissue viability grade on the basis of the perfusion CT parameters in acute stroke patients. A multimodal CT imaging protocol; unenhanced CT of the brain, CT angiography of head and neck blood vessels, followed by brain perfusion CT and 24 h follow-up brain CT was performed. Perfusion deficits were detected first visually, with subsequent manual quantitative and relative measurements in affected and contra-lateral hemisphere in 87 acute stroke patients. Visual perfusion deficit on perfusion CT images was found in 78 cases (38 women, 40 men; mean age, 30-84 years). Penumbra lesions (n = 49) and core lesions (n = 42) were detected by increased mean transit time (MTT) on perfusion CT maps in comparison to contra-lateral hemispheres. Cerebral blood volume (CBV) mean values in the penumbra group were increased in the penumbra group and decreased in the core group. Cerebral blood flow (CBF) values were decreased in penumbra and markedly decreased in core lesion. Perfusion CT measurements are reliable in estimation of penumbra and core lesions in acute stroke patients, if relative threshold values are used. The most accurate parameter of hypoperfusion is increased MTT above 190%. Relative threshold values for irreversible lesion are CBF <30-40% and CBV <40% in comparison to contra-lateral hemisphere. Penumbra lesion is characterized by MTT increase and CBF decrease, while CBV shows variable values.

  8. An effective hair detection algorithm for dermoscopic melanoma images of skin lesions

    NASA Astrophysics Data System (ADS)

    Chakraborti, Damayanti; Kaur, Ravneet; Umbaugh, Scott; LeAnder, Robert

    2016-09-01

    Dermoscopic images are obtained using the method of skin surface microscopy. Pigmented skin lesions are evaluated in terms of texture features such as color and structure. Artifacts, such as hairs, bubbles, black frames, ruler-marks, etc., create obstacles that prevent accurate detection of skin lesions by both clinicians and computer-aided diagnosis. In this article, we propose a new algorithm for the automated detection of hairs, using an adaptive, Canny edge-detection method, followed by morphological filtering and an arithmetic addition operation. The algorithm was applied to 50 dermoscopic melanoma images. In order to ascertain this method's relative detection accuracy, it was compared to the Razmjooy hair-detection method [1], using segmentation error (SE), true detection rate (TDR) and false positioning rate (FPR). The new method produced 6.57% SE, 96.28% TDR and 3.47% FPR, compared to 15.751% SE, 86.29% TDR and 11.74% FPR produced by the Razmjooy method [1]. Because of the 7.27-9.99% improvement in those parameters, we conclude that the new algorithm produces much better results for detecting thick, thin, dark and light hairs. The new method proposed here, shows an appreciable difference in the rate of detecting bubbles, as well.

  9. Evaluation of penalty design in penalized maximum-likelihood image reconstruction for lesion detection

    NASA Astrophysics Data System (ADS)

    Yang, Li; Ferrero, Andrea; Hagge, Rosalie J.; Badawi, Ramsey D.; Qi, Jinyi

    2014-03-01

    Detecting cancerous lesions is a major clinical application in emission tomography. In previous work, we have studied penalized maximum-likelihood (PML) image reconstruction for the detection task, where we used a multiview channelized Hotelling observer (mvCHO) to assess the lesion detectability in 3D images. It mimics the condition where a human observer examines three orthogonal views of a 3D image for lesion detection. We proposed a method to design a shift-variant quadratic penalty function to improve the detectability of lesions at unknown locations, and validated it using computer simulations. In this study we evaluated the bene t of the proposed penalty function for lesion detection using real data. A high-count real patient data with no identi able tumor inside the eld of view was used as the background data. A Na-22 point source was scanned in air at variable locations and the point source data were superimposed onto the patient data as arti cial lesions after being attenuated by the patient body. Independent Poisson noise was added to the high-count sinograms to generate 200 pairs of lesion-present and lesion-absent data sets, each mimicking a 5-minute scans. Lesion detectability was assessed using a multiview CHO and a human observer two alternative forced choice (2AFC) experiment. The results showed that the optimized penalty can improve lesion detection over the conventional quadratic penalty function.

  10. Is anterior communicating artery syndrome related to fornix lesions?

    PubMed

    Molino, Ivana; Cavaliere, Carlo; Salvatore, Elena; Quarantelli, Mario; Colucci, Luisa; Fasanaro, Angiola Maria

    2014-01-01

    Anterior communicating artery (ACoA) syndrome, which may occur after rupture of ACoA aneurysms, consists of anterograde memory problems, executive dysfunctions, confabulations, and personality changes. Recently, the employment of diffusion tensor tractography (DTT) has related ACoA to microstructural lesions in the cingulum and the fornix, but an accurate characterization of these subjects should be provided. We report the clinical and neuropsychological findings of a patient who developed a severe and persistent amnesia together with significant behavioral changes, as well as her imaging results, where the sole evidence of brain damage was that of the fornix demonstrated by DTT. The four-year neuropsychological follow-up of the subject allows exclusion of other causes. This case demonstrates that microstructural lesions of fornix may lead to persistent amnesia, executive impairments, and behavioral changes and contributes to the knowledge of its role in cognition.

  11. A method for mass candidate detection and an application to liver lesion detection

    NASA Astrophysics Data System (ADS)

    Costa, Maria J.; Tsymbal, Alexey; Nguatem, William; Suehling, Michael; Zhou, S. Kevin; Comaniciu, Dorin

    2011-03-01

    Detection and segmentation of abnormal masses within organs in Computed Tomography (CT) images of patients is of practical importance in computer-aided diagnosis (CAD), treatment planning, and analysis of normal as well as pathological regions. For intervention planning e.g. in radiotherapy the detection of abnormal masses is essential for patient diagnosis, personalized treatment choice and follow-up. The unpredictable nature of disease often makes the detection of the presence, appearance, shape, size and number of abnormal masses a challenging task, which is particularly tedious when performed by hand. Moreover, in cases in which the imaging protocol specifies the administration of a contrast agent, the contrast agent phases at which the patient images are acquired have a dramatic influence on the shape and appearance of the diseased masses. In this paper we propose a method to automatically detect candidate lesions (CLs) in 3D CTs of liver lesions. We introduce a novel multilevel candidate generation method that proves clearly advantageous in a comparative study with a state of the art approach. A learning-based selection module and a candidate fusion module are then introduced to reduce both redundancy and the false positive rate. The proposed workflow is applied to the detection of both hyperdense and hypodense hepatic lesions in all contrast agent phases, with resulting sensitivities of 89.7% and 92% and positive predictive values of 82.6% and 87.6% respectively.

  12. In vivo light scattering for the detection of cancerous and precancerous lesions of the cervix

    SciTech Connect

    Mourant, Judith R

    2008-01-01

    A noninvasive optical diagnostic system for detection of cancerous and precancerous lesions of the cervix was evaluated in vivo. The optical system included a fiber-optic probe designed to measure polarized and unpolarized light transport properties of a small volume of tissue. An algorithm for diagnosing tissue based on the optical measurements was developed that used four optical properties, three of which were related to light scattering properties and the fourth of which was related to hemoglobin concentration. A sensitivity of {approx}77% and specificities in the mid 60% range were obtained for separating high grade squamous intraepithelial lesions and cancer from other pathologies and normal tissue. The use of different cross-validation methods in algorithm development is analyzed, and the relative difficulties of diagnosing certain pathologies are assessed. Furthermore, the robustness of the optical system for use by different doctors and to changes in fiber-optic probe are also assessed, and potential improvements in the optical system are discussed.

  13. A case-control study of GST polymorphisms and arsenic related skin lesions

    PubMed Central

    McCarty, Kathleen M; Ryan, Louise; Houseman, E Andres; Williams, Paige L; Miller, David P; Quamruzzaman, Quazi; Rahman, Mahmuder; Mahiuddin, Golam; Smith, Thomas; Gonzalez, Ernesto; Su, Li; Christiani, David C

    2007-01-01

    Background Polymorphisms in GSTT1, GSTM1 and GSTP1 impact detoxification of carcinogens by GSTs and have been reported to increase susceptibility to environmentally related health outcomes. Individual factors in arsenic biotransformation may influence disease susceptibility. GST activity is involved in the metabolism of endogenous and exogenous compounds, including catalyzing the formation of arsenic-GSH conjugates. Methods We investigated whether polymorphisms in GSTT1, GSTP1 and GSTM1 were associated with risk of skin lesions and whether these polymorphisms modify the relationship between drinking water arsenic exposure and skin lesions in a case control study of 1200 subjects frequency matched on age and gender in community clinics in Pabna, Bangladesh in 2001–2002. Results and discussion GSTT1 homozygous wildtype status was associated with increased odds of skin lesions compared to the null status (OR1.56 95% CI 1.10–2.19). The GSTP1 GG polymorphism was associated with greater odds of skin lesions compared to GSTP1 AA, (OR 1.86 (95%CI 1.15–3.00). No evidence of effect modification by GSTT1, GSTM1 or GSTP1 polymorphisms on the association between arsenic exposure and skin lesions was detected. Conclusion GSTT1 wildtype and GSTP1 GG are associated with increased risk of skin lesions. PMID:17284320

  14. Relating to ion detection

    DOEpatents

    Orr, Christopher Henry; Luff, Craig Janson; Dockray, Thomas; Macarthur, Duncan Whittemore

    2001-01-01

    The apparatus and method provide a technique for improving detection of alpha and/or beta emitting sources on items or in locations using indirect means. The emission forms generate ions in a medium surrounding the item or location and the medium is then moved to a detecting location where the ions are discharged to give a measure of the emission levels. To increase the level of ions generated and render the system particularly applicable for narrow pipes and other forms of conduits, the medium pressure is increased above atmospheric pressure. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

  15. Is the morphology and activity of the occlusal carious lesion related to the lesion progression stage?

    PubMed

    Neves, Aline Almeida; Vargas, Daniel Otero Amaral; Santos, Thais Maria Pires; Lopes, Ricardo Tadeu; Sousa, Frederico Barbosa

    2016-12-01

    To investigate the relationship between degree of dentin demineralization with both lesion activity and morphology of the occlusal carious cavity. Occlusal sites (n=138) were identified by visual examination (Nyvad's scores 0-6) in 67 extracted teeth which were scanned in a high energy micro-CT. After 3D reconstruction, each stack was resliced in the mesio-distal direction and tooth mineral density (MD) was measured along a path from enamel to the deepest part of dentin in the slice showing the most severe carious involvement. Each site was classified in "open" or "closed" (if cavitated) depending on the morphology of the surrounding enamel walls as measured using micro-CT and as active or inactive in enamel or dentin by a clinical scoring system. Lesions showing dentin cavitation presented higher demineralization degree compared to non-cavitated, or enamel cavitated lesions. Inactive lesions presented lower demineralization degree compared to active lesions, although with a low effect size. According to the morphological aspect of the carious cavity, open enamel lesions showed lower dentin demineralization degree than closed lesion environments. Active lesions showed higher dentin demineralization degree than inactive ones, while lesions showing closed cavitation resulted in higher dentin demineralization degree only for enamel lesions. Including those parameters in treatment decisions may help to improve prognosis and increase effectiveness of the caries diagnostic systems in the clinical setting. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Anal human papillomavirus infection: prevalence, diagnosis and treatment of related lesions.

    PubMed

    Benevolo, Maria; Donà, Maria Gabriella; Ravenda, Paola Simona; Chiocca, Susanna

    2016-01-01

    Human papillomavirus (HPV) infection is mostly asymptomatic, but may also have many diverse clinical signs encompassing benign ano-genital lesions, and carcinomas. Recently, interest has also particularly focused on anal cancer since, over the last decades, its incidence has been greatly increasing in developed countries, both in women and men and is drastically higher in specific risk groups, such as men who have sex with men (MSM) and HIV-1 infected individuals. Approximately 88% of anal cancer cases worldwide are associated with HPV infection. This review summarizes our current understanding of anal HPV infection, discussing its epidemiology and risk factors in various populations, and the state of the art in the detection of anal HPV infection and its related lesions through both cytology and histology. Finally, we discuss the clinical management and therapy for these lesions.

  17. Lesion detectability in stereoscopically viewed digital breast tomosynthesis projection images: a model observer study with anthropomorphic computational breast phantoms

    NASA Astrophysics Data System (ADS)

    Reinhold, Jacob; Wen, Gezheng; Lo, Joseph Y.; Markey, Mia K.

    2017-03-01

    Stereoscopic views of 3D breast imaging data may better reveal the 3D structures of breasts, and potentially improve the detection of breast lesions. The imaging geometry of digital breast tomosynthesis (DBT) lends itself naturally to stereo viewing because a stereo pair can be easily formed by two projection images with a reasonable separation angle for perceiving depth. This simulation study attempts to mimic breast lesion detection on stereo viewing of a sequence of stereo pairs of DBT projection images. 3D anthropomorphic computational breast phantoms were scanned by a simulated DBT system, and spherical signals were inserted into different breast regions to imitate the presence of breast lesions. The regions of interest (ROI) had different local anatomical structures and consequently different background statistics. The projection images were combined into a sequence of stereo pairs, and then presented to a stereo matching model observer for determining lesion presence. The signal-to-noise ratio (SNR) was used as the figure of merit in evaluation, and the SNR from the stack of reconstructed slices was considered as the benchmark. We have shown that: 1) incorporating local anatomical backgrounds may improve lesion detectability relative to ignoring location-dependent image characteristics. The SNR was lower for the ROIs with the higher local power-law-noise coefficient β. 2) Lesion detectability may be inferior on stereo viewing of projection images relative to conventional viewing of reconstructed slices, but further studies are needed to confirm this observation.

  18. Time resolved optical detection for white matter lesion detection: preclinical tests on macaque brains and MRI co-registration

    NASA Astrophysics Data System (ADS)

    Planat-Chrétien, A.; Berger, M.; Hervé, L.; Watroba, L.; Demilly, J.; Flament, J.; Stimmer, L.; Aubourg, P.; Dinten, J.-M.

    2015-07-01

    We conducted a preclinical assessment on young macaques aimed at detecting white matter lesions. We present the protocol we implemented to achieve the lesions detection using a bedside non-invasive optical-based Time-Resolved instrumentation we have optimized for this purpose. We validated the reconstructed 3D absorption map with co-registration of MRI data.

  19. Early-Stage White Matter Lesions Detected by Multispectral MRI Segmentation Predict Progressive Cognitive Decline

    PubMed Central

    Jokinen, Hanna; Gonçalves, Nicolau; Vigário, Ricardo; Lipsanen, Jari; Fazekas, Franz; Schmidt, Reinhold; Barkhof, Frederik; Madureira, Sofia; Verdelho, Ana; Inzitari, Domenico; Pantoni, Leonardo; Erkinjuntti, Timo

    2015-01-01

    White matter lesions (WML) are the main brain imaging surrogate of cerebral small-vessel disease. A new MRI tissue segmentation method, based on a discriminative clustering approach without explicit model-based added prior, detects partial WML volumes, likely representing very early-stage changes in normal-appearing brain tissue. This study investigated how the different stages of WML, from a “pre-visible” stage to fully developed lesions, predict future cognitive decline. MRI scans of 78 subjects, aged 65–84 years, from the Leukoaraiosis and Disability (LADIS) study were analyzed using a self-supervised multispectral segmentation algorithm to identify tissue types and partial WML volumes. Each lesion voxel was classified as having a small (33%), intermediate (66%), or high (100%) proportion of lesion tissue. The subjects were evaluated with detailed clinical and neuropsychological assessments at baseline and at three annual follow-up visits. We found that voxels with small partial WML predicted lower executive function compound scores at baseline, and steeper decline of executive scores in follow-up, independently of the demographics and the conventionally estimated hyperintensity volume on fluid-attenuated inversion recovery images. The intermediate and fully developed lesions were related to impairments in multiple cognitive domains including executive functions, processing speed, memory, and global cognitive function. In conclusion, early-stage partial WML, still too faint to be clearly detectable on conventional MRI, already predict executive dysfunction and progressive cognitive decline regardless of the conventionally evaluated WML load. These findings advance early recognition of small vessel disease and incipient vascular cognitive impairment. PMID:26696814

  20. Volume Navigation Technique for Ultrasound-Guided Biopsy of Breast Lesions Detected Only at MRI.

    PubMed

    Aribal, Erkin; Tureli, Derya; Kucukkaya, Fikret; Kaya, Handan

    2017-06-01

    The purpose of this study is to assess the utility of a volume navigation technique (VNT) for ultrasound-guided biopsy of MRI-detected, but sonographically ambiguous or occult, breast lesions. Within a recruitment period of 13 months (January 1, 2014, through February 1, 2015), 22 patients with 26 BI-RADS category 4 or 5 lesions that were detected at MRI but missed at second-look ultrasound were reimaged using a rapid sequence and a flexible body coil in a 3-T MRI scanner. Patients were supine, with three skin markers placed on the breasts. MRI volume data were coregistered to real-time ultrasound in a dedicated platform, and MRI-detected lesions (six masses, 11 nonmass enhancements, eight foci, and one architectural distortion) were sought using VNT-guided ultrasound. Five needle biopsy specimens were obtained either from each sonographically detected lesion (n = 11) or from VNT-guided sonographically localized breast volume corresponding to the MRI-detected, but still ultrasound-occult, lesions (n = 15). Histopathologic analysis revealed 18 benign and six malignant lesions. The remaining two lesions, both of which appeared as masses at MRI, were high risk and were upgraded to carcinoma after excisional biopsy. All malignant lesions underwent curative surgery; the final histopathologic diagnoses remained unchanged. Of the six malignant lesions, one was a mass, three were nonmass enhancements, and two were enhancing foci at MRI. Three malignant lesions were occult at ultrasound, and three were discerned as subtle hypoechoic changes. No benign lesion was sonographically visualized as a mass, and none progressed, with 56% disappearing at MRI performed during the follow-up period (mean, 14 months). Coregistration of MRI and real-time ultrasound enables sonographic localization of breast lesions detected at MRI only. VNT is a feasible alternative to MRI-guided biopsy of ultrasound-occult breast lesions.

  1. A novel autoantibody test for the detection of pre-neoplastic lung lesions

    PubMed Central

    2014-01-01

    Background Atypical adenomatous hyperplasia (AAH) and squamous cell dysplasia (SCD) are associated with the development of malignant lesions in the lung. Accurate diagnosis of AAH and SCD could facilitate earlier clinical intervention and provide useful information for assessing lung cancer risk in human populations. Detection of AAH and SCD has been achieved by imaging and bronchoscopy clinically, but sensitivity and specificity remain less than satisfactory. We utilized the ability of the immune system to identify lesion specific proteins for detection of AAH and SCD. Methods AAH and SCD tissue was surgically removed from six patients of Chinese descent (3 AAH and 3 SCD) with corresponding serum samples. Total RNA was extracted from the tissues and a cDNA library was generated and incorporated into a T7 bacteriophage vector. Following enrichment to remove "normal" reactive phages, a total of 200 AAH related and 200 SCD related phage clones were chosen for statistical classifier development and incorporation into a microarray. Microarray slides were tested with an independent double-blinded population consisting of 100 AAH subjects, 100 SCD subjects and 200 healthy control subjects. Results Sensitivity of 82% and specificity of 70% were achieved in the detection of AAH using a combination of 9 autoantibody biomarkers. Likewise, 86% sensitivity and 78% specificity were achieved in the detection of SCD using a combination of 13 SCD-associated markers. Sequencing analysis identified that most of these 22 autoantibody biomarkers had known malignant associations. Conclusions Both diagnostic values showed promising sensitivity and specificity in detection of pre-neoplastic lung lesions. Hence, this technology could be a useful non-invasive tool to assess lung cancer risk in human populations. PMID:24708840

  2. Detecting and treating occlusal caries lesions: a cost-effectiveness analysis.

    PubMed

    Schwendicke, F; Stolpe, M; Meyer-Lueckel, H; Paris, S

    2015-02-01

    The health gains and costs resulting from using different caries detection strategies might not only depend on the accuracy of the used method but also the treatment emanating from its use in different populations. We compared combinations of visual-tactile, radiographic, or laser-fluorescence-based detection methods with 1 of 3 treatments (non-, micro-, and invasive treatment) initiated at different cutoffs (treating all or only dentinal lesions) in populations with low or high caries prevalence. A Markov model was constructed to follow an occlusal surface in a permanent molar in an initially 12-y-old male German patient over his lifetime. Prevalence data and transition probabilities were extracted from the literature, while validity parameters of different methods were synthesized or obtained from systematic reviews. Microsimulations were performed to analyze the model, assuming a German health care setting and a mixed public-private payer perspective. Radiographic and fluorescence-based methods led to more overtreatments, especially in populations with low prevalence. For the latter, combining visual-tactile or radiographic detection with microinvasive treatment retained teeth longest (mean 66 y) at lowest costs (329 and 332 Euro, respectively), while combining radiographic or fluorescence-based detections with invasive treatment was the least cost-effective (<60 y, >700 Euro). In populations with high prevalence, combining radiographic detection with microinvasive treatment was most cost-effective (63 y, 528 Euro), while sensitive detection methods combined with invasive treatments were again the least cost-effective (<59 y, >690 Euro). The suitability of detection methods differed significantly between populations, and the cost-effectiveness was greatly influenced by the treatment initiated after lesion detection. The accuracy of a detection method relative to a "gold standard" did not automatically convey into better health or reduced costs. Detection methods

  3. EUS is superior for detection of pancreatic lesions compared with standard imaging in patients with multiple endocrine neoplasia type 1.

    PubMed

    van Asselt, Sophie J; Brouwers, Adrienne H; van Dullemen, Hendrik M; van der Jagt, Eric J; Bongaerts, Alfons H H; Kema, Ido P; Koopmans, Klaas P; Valk, Gerlof D; Timmers, Henri J; de Herder, Wouter W; Feelders, Richard A; Fockens, Paul; Sluiter, Wim J; de Vries, Elisabeth G E; Links, Thera P

    2015-01-01

    In multiple endocrine neoplasia type 1 (MEN1), pancreatic neuroendocrine tumors (pNETs) are the leading MEN1-related cause of death. To evaluate EUS and (11)C-5-hydroxytryptophan positron emission tomography ((11)C-5-HTP PET), compared with the recommended screening techniques in MEN1 patients for early detection of pNETs. Cross-sectional study. Tertiary-care university medical center. This study involved 41 patients with a proven MEN1 mutation or with one MEN1 manifestation and a mutation carrier as a first-degree family member, with recent screening by abdominal CT or magnetic resonance imaging (MRI) and somatostatin receptor scintigraphy (SRS). EUS by using a linear Pentax echoendoscope and Hitachi EUB-525 and (11)C-5-HTP PET. Patient-based and lesion-based positivity for pNET was calculated for all imaging techniques. The McNemar test was used to compare the yield of the 4 imaging techniques. In 35 of 41 patients, 107 pancreatic lesions were detected in total. EUS detected 101 pancreatic lesions in 34 patients, (11)C-5-HTP PET detected 35 lesions in 19 patients, and CT/MRI + SRS detected 32 lesions in 18 patients (P < .001). (11)C-5-HTP PET performed similarly to CT/MRI + SRS and better compared with SRS only (13 lesions in 12 patients), both at a patient-based and lesion-based level (P < .05). Single-center study. EUS is superior to CT/MRI + SRS for pancreatic lesion detection in patients with MEN1. In this setting, (11)C-5-HTP PET is not useful. We recommend EUS as the first-choice pancreas imaging technique in patients with MEN1. ( NTR1668.). Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  4. Evaluating lesion segmentation on breast sonography as related to lesion type.

    PubMed

    Pons, Gerard; Martí, Joan; Martí, Robert; Ganau, Sergi; Vilanova, Joan Carles; Noble, J Alison

    2013-09-01

    Breast sonography currently provides a complementary diagnosis when other modalities are not conclusive. However, lesion segmentation on sonography is still a challenging problem due to the presence of artifacts. To solve these problems, Markov random fields and maximum a posteriori-based methods are used to estimate a distortion field while identifying regions of similar intensity inhomogeneity. In this study, different initialization approaches were exhaustively evaluated using a database of 212 B-mode breast sonograms and considering the lesion types. Finally, conclusions about the relationship between the segmentation results and lesions types are described.

  5. Low-contrast focal lesion detectability phantom for 1H MR imaging.

    PubMed

    Madsen, E L; Blechinger, J C; Frank, G R

    1991-01-01

    A phantom made from tissue-mimicking materials is reported for testing 1H MRI systems regarding their ability to detect small low-contrast focal lesions and to delineate the boundaries of larger lesions. Two sets of seven spherical simulated lesions with diameters of 2, 3, 4, 5, 6.3, 7.9, and 9.5 mm have T1 and T2 values somewhat higher than the corresponding values in the surrounding simulated normal tissue. Relaxometer determinations of T1 and T2 for the simulated normal tissue yielded 955 and 106 ms, respectively, at 22 degrees C and 1 T. The corresponding values in set #1 of the simulated lesions were 1017 and 175 ms and in set #2 were 1002 and 127 ms. These T1 and T2 values are similar to those for brain and brain lesions but are too high to represent soft tissue such as liver and muscle. The centers of the 14 lesions are coplanar, and eight alignment devices surround them facilitating superposition of the scan plane and the plane containing the centers of the lesions. Illustrative images made with a 1.5-T system are shown. All simulated lesions are detectable in T2-weighted head coil images. Corresponding T1-weighted images are also shown, the 2- and 3-mm lesions of set #2 and the 2-mm lesion of set #1 not being detectable. The phantoms could be useful for performance or acceptance testing and perhaps for quality assurance testing.

  6. Lesion Detection in CT Images Using Deep Learning Semantic Segmentation Technique

    NASA Astrophysics Data System (ADS)

    Kalinovsky, A.; Liauchuk, V.; Tarasau, A.

    2017-05-01

    In this paper, the problem of automatic detection of tuberculosis lesion on 3D lung CT images is considered as a benchmark for testing out algorithms based on a modern concept of Deep Learning. For training and testing of the algorithms a domestic dataset of 338 3D CT scans of tuberculosis patients with manually labelled lesions was used. The algorithms which are based on using Deep Convolutional Networks were implemented and applied in three different ways including slice-wise lesion detection in 2D images using semantic segmentation, slice-wise lesion detection in 2D images using sliding window technique as well as straightforward detection of lesions via semantic segmentation in whole 3D CT scans. The algorithms demonstrate superior performance compared to algorithms based on conventional image analysis methods.

  7. Impact of compressed breast thickness and dose on lesion detectability in digital mammography: FROC study with simulated lesions in real mammograms.

    PubMed

    Salvagnini, Elena; Bosmans, Hilde; Van Ongeval, Chantal; Van Steen, Andreas; Michielsen, Koen; Cockmartin, Lesley; Struelens, Lara; Marshall, Nicholas W

    2016-09-01

    The aim of this work was twofold: (1) to examine whether, with standard automatic exposure control (AEC) settings that maintain pixel values in the detector constant, lesion detectability in clinical images decreases as a function of breast thickness and (2) to verify whether a new AEC setup can increase lesion detectability at larger breast thicknesses. Screening patient images, acquired on two identical digital mammography systems, were collected over a period of 2 yr. Mammograms were acquired under standard AEC conditions (part 1) and subsequently with a new AEC setup (part 2), programmed to use the standard AEC settings for compressed breast thicknesses ≤49 mm, while a relative dose increase was applied above this thickness. The images were divided into four thickness groups: T1 ≤ 29 mm, T2 = 30-49 mm, T3 = 50-69 mm, and T4 ≥ 70 mm, with each thickness group containing 130 randomly selected craniocaudal lesion-free images. Two measures of density were obtained for every image: a BI-RADS score and a map of volumetric breast density created with a software application (VolparaDensity, Matakina, NZ). This information was used to select subsets of four images, containing one image from each thickness group, matched to a (global) BI-RADS score and containing a region with the same (local) volpara volumetric density value. One selected lesion (a microcalcification cluster or a mass) was simulated into each of the four images. This process was repeated so that, for a given thickness group, half the images contained a single lesion and half were lesion-free. The lesion templates created and inserted in groups T3 and T4 for the first part of the study were then inserted into the images of thickness groups T3 and T4 acquired with higher dose settings. Finally, all images were visualized using the ViewDEX software and scored by four radiologists performing a free search study. A statistical jackknife-alternative free-response receiver operating characteristic

  8. Effective detection of bronchial preinvasive lesions by a new autofluorescence imaging bronchovideoscope system.

    PubMed

    Chiyo, Masako; Shibuya, Kiyoshi; Hoshino, Hidehisa; Yasufuku, Kazuhiro; Sekine, Yasuo; Iizasa, Toshihiko; Hiroshima, Kenzo; Fujisawa, Takehiko

    2005-06-01

    Autofluorescence bronchoscopy is an important tool for the early detection of preinvasive bronchial lesions. However, autofluorescence bronchoscopy has difficulty distinguishing between preinvasive lesions and other benign epithelial changes. A new autofluorescence imaging bronchovideoscope system (AFI) comprises three signals, including an autofluorescence (460-690 nm) on excitation blue light (395-445 nm) and two different bands of reflected light: G' (550 nm) and R' (610 nm). We hypothesized that color analyses of these three wave lengths would improve our ability to differentiate between inflammation and preinvasive lesions. In order to prove this hypothesis and to evaluate the efficacy of AFI for detecting preinvasive lesions, we conducted a prospective study. A total of 32 patients with suspected or known lung cancer were entered into this study. Conventional white light bronchovideoscopy (WLB) and light induced fluorescence endoscopy (LIFE) were performed prior to using AFI. WLB and LIFE detected 62 lesions, including lung cancers (n=2), squamous dysplasias (n=30), and bronchitis (n=30). By utilizing AFI, 24 dysplasias and 2 cancer lesions were magenta in color, while 25 bronchitis lesions were blue. The sensitivities of detecting dysplasia by LIFE and AFI were 96.7% and 80%, respectively. The specificity of AFI (83.3%) was significantly higher than that of LIFE (36.6%) (p=0.0005). We conclude that AFI appears to represent a significant advance in distinguishing preinvasive and malignant lesions from bronchitis or hyperplasia under circumstances where LIFE would identify these all as abnormal lesions.

  9. How do kV and mAs affect CT lesion detection performance?

    NASA Astrophysics Data System (ADS)

    Huda, W.; Ogden, K. M.; Shah, K.; Jadoo, C.; Scalzetti, E. M.; Lavallee, R. L.; Roskopf, M. L.

    2007-03-01

    The purpose of this study was to investigate how output (mAs) and x-ray tube voltage (kV) affect lesion detection in CT imaging. An adult Rando phantom was scanned on a GE LightSpeed CT scanner at x-ray tube voltages from 80 to 140 kV, and outputs from 90 to 360 mAs. Axial images of the abdomen were reconstructed and viewed on a high quality monitor at a soft tissue display setting. We measured detection of 2.5 to 12.5 mm sized lesions using a 2 Alternate Forced Choice (2-AFC) experimental paradigm that determined lesion contrast (I) corresponding to a 92% accuracy (I 92%) of lesion detection. Plots of log(I 92%) versus log(lesion size) were all approximately linear. The slope of the contrast detail curve was ~ -1.0 at 90 mAs, close to the value predicted by the Rose model, but monotonically decreased with increasing mAs to a value of ~ -0.7 at 360 mAs. Increasing the x-ray tube output by a factor of four improved lesion detection by a factor of 1.9 for the smallest lesion (2.5 mm), close to the value predicted by the Rose model, but only by a factor of 1.2 for largest lesion (12.5 mm). Increasing the kV monotonically decreased the contrast detail slopes from -1.02 at 80 kV to -0.71 at 140 kV. Increasing the x-ray tube voltage from 80 to 140 kV improved lesion detection by a factor of 2.8 for the smallest lesion (2.5 mm), but only by a factor of 1.7 for largest lesion (12.5 mm). We conclude that: (i) quantum mottle is an important factor for low contrast lesion detection in images of anthropomorphic phantoms; (ii) x-ray tube voltage has a much greater influence on lesion detection performance than x-ray tube output; (iii) the Rose model only predicts CT lesion detection performance at low x-ray tube outputs (90 mAs) and for small lesions (2.5 mm).

  10. Use of adaptive hybrid filtering process in Crohn's disease lesion detection from real capsule endoscopy videos.

    PubMed

    Charisis, Vasileios S; Hadjileontiadis, Leontios J

    2016-03-01

    The aim of this Letter is to present a new capsule endoscopy (CE) image analysis scheme for the detection of small bowel ulcers that relate to Crohn's disease. More specifically, this scheme is based on: (i) a hybrid adaptive filtering (HAF) process, that utilises genetic algorithms to the curvelet-based representation of images for efficient extraction of the lesion-related morphological characteristics, (ii) differential lacunarity (DL) analysis for texture feature extraction from the HAF-filtered images and (iii) support vector machines for robust classification performance. For the training of the proposed scheme, namely HAF-DL, an 800-image database was used and the evaluation was based on ten 30-second long endoscopic videos. Experimental results, along with comparison with other related efforts, have shown that the HAF-DL approach evidently outperforms the latter in the field of CE image analysis for automated lesion detection, providing higher classification results. The promising performance of HAF-DL paves the way for a complete computer-aided diagnosis system that could support the physicians' clinical practice.

  11. Use of adaptive hybrid filtering process in Crohn's disease lesion detection from real capsule endoscopy videos

    PubMed Central

    Charisis, Vasileios S.

    2016-01-01

    The aim of this Letter is to present a new capsule endoscopy (CE) image analysis scheme for the detection of small bowel ulcers that relate to Crohn's disease. More specifically, this scheme is based on: (i) a hybrid adaptive filtering (HAF) process, that utilises genetic algorithms to the curvelet-based representation of images for efficient extraction of the lesion-related morphological characteristics, (ii) differential lacunarity (DL) analysis for texture feature extraction from the HAF-filtered images and (iii) support vector machines for robust classification performance. For the training of the proposed scheme, namely HAF-DL, an 800-image database was used and the evaluation was based on ten 30-second long endoscopic videos. Experimental results, along with comparison with other related efforts, have shown that the HAF-DL approach evidently outperforms the latter in the field of CE image analysis for automated lesion detection, providing higher classification results. The promising performance of HAF-DL paves the way for a complete computer-aided diagnosis system that could support the physicians’ clinical practice. PMID:27222730

  12. Nuclear factor erythroid 2-related factor gene variants and susceptibility of arsenic-related skin lesions.

    PubMed

    Cordova, E J; Valenzuela, O L; Sánchez-Peña, L C; Escamilla-Guerrero, G; Hernández-Zavala, A; Orozco, L; Del Razo, L M

    2014-06-01

    Inorganic arsenic (iAs) is an important pollutant associated with various chronic-degenerative diseases. The cytoprotective protein nuclear factor erythroid 2-related factor (NRF2) has been proposed as an important responsive mechanism against iAs exposure. The aim of this study was to determine whether the risk of skin lesions in people exposed to iAs-contaminated water could be modified by the presence of single nucleotide polymorphisms in the NRF2 coding gene. We studied 117 individuals with long-term iAs exposure and 120 nonexposed individuals. Total As was determined in water, meanwhile iAs and its metabolites were measured in urine. The iAs-induced skin lesion status was evaluated by expert dermatologists. We sequenced the promoter region of NRF2 in a sample of 120 healthy donors. We found four polymorphisms previously reported and one novel polymorphism in the 5' regulatory region of the NRF2. In this study, we did not find allelic and genotype association of NRF2 polymorphisms with iAs-related skin lesion. However, the analysis of haplotypes composed by -653GA, and -617CA NRF2 single nucleotide polymorphisms showed a significant association with protection against skin lesions in the low-As exposure group. This is the first report studying the association between NRF2 polymorphisms and susceptibility of As-related skin lesions. Increasing the sample size will allow us to confirm this data. © The Author(s) 2014.

  13. An in vitro comparison of detection methods for approximal carious lesions in primary molars.

    PubMed

    Chawla, N; Messer, L B; Adams, G G; Manton, D J

    2012-01-01

    This study aimed to compare and contrast in vitro six methods to determine the most accurate method for detecting approximal carious lesions in primary molars. Extracted primary molars (n = 140) were stored in 0.02% chlorhexidine solution and mounted in light-cured resin in pairs. The six carious lesion detection methods used by the three examiners to assess approximal carious lesions were visual inspection, digital radiography, two transillumination lights (SDI and NSK), and two laser fluorescence instruments (CDD and DDP). Five damaged teeth were discarded. The teeth (n = 135) were sectioned, serially ground, and examined under light microscopy using Downer's histological (HST) criteria as the gold standard. Intra- and inter-examiner reliability, agreement with HST, specificity, sensitivity, receiver operating characteristic (ROC) curves, and areas under the curve were calculated. This study found visual inspection to be the most accurate method when validated by histology. Transillumination with NSK light had the highest specificity, and digital radiography had the highest sensitivity for detecting enamel and/or dentinal carious lesions. Combining specificity and sensitivity into the area under ROC curves, enamel plus dentinal lesions were detected most accurately by visual inspection followed by digital radiography; dentinal lesions were detected most accurately by digital radiography followed by visual inspection. None of the four newly developed methods can be recommended as suitable replacements for visual inspection and digital radiography in detecting carious lesions on approximal surfaces of primary molars, and further developmental work is needed. Copyright © 2012 S. Karger AG, Basel.

  14. Diagnostic accuracy of noncontrast MRI for detection of glenohumeral cartilage lesions: a prospective comparison to arthroscopy.

    PubMed

    VanBeek, Corinne; Loeffler, Bryan J; Narzikul, Alexa; Gordon, Victoria; Rasiej, Michael J; Kazam, Jonathan K; Abboud, Joseph A

    2014-07-01

    The purpose of this study was to determine the prevalence of glenohumeral articular cartilage lesions in patients with rotator cuff tendinopathy and to assess the accuracy of noncontrast magnetic resonance imaging (MRI) in detecting these defects compared with the "gold standard" of arthroscopy. Noncontrast MRI studies obtained in 84 consecutive patients undergoing shoulder arthroscopy for rotator cuff tendinopathy (mean age, 54.8 years; range, 17-82 years) were prospectively evaluated for glenohumeral cartilage lesions. Two fellowship-trained, experienced musculoskeletal radiologists were blinded from the arthroscopic findings and independently evaluated the glenoid and humeral head cartilage on 2 separate occasions. At arthroscopy, cartilage lesions of the humeral head were detected in 23 patients (frequency, 27.4%), and glenoid cartilage lesions were found in 20 patients (frequency, 23.8%). For detection of a humeral lesion on MRI, the radiologists' combined accuracy was 78%, sensitivity was 43%, and specificity was 91%. The combined accuracy for detection of glenoid lesions on MRI was 84%, sensitivity was 53%, and specificity was 93%. Combining the readers, low-grade lesions (International Cartilage Repair Society grades 1 and 2) of the glenoid and humerus were read as negative on MRI in 63% and 86% of cases, respectively. Overall accuracy of noncontrast MRI for detection of glenohumeral articular cartilage lesions is good; however, interpretation is reader dependent, and accuracy is significantly reduced for detection of low-grade lesions. On the basis of these findings, we recommend that patients with rotator cuff tendinopathy undergoing arthroscopy be informed that the presence and severity of cartilage lesions may be underestimated on MRI. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  15. Seven-Tesla Magnetization Transfer Imaging to Detect Multiple Sclerosis White Matter Lesions.

    PubMed

    Chou, I-Jun; Lim, Su-Yin; Tanasescu, Radu; Al-Radaideh, Ali; Mougin, Olivier E; Tench, Christopher R; Whitehouse, William P; Gowland, Penny A; Constantinescu, Cris S

    2017-09-25

    Fluid-attenuated inversion recovery (FLAIR) imaging at 3 Tesla (T) field strength is the most sensitive modality for detecting white matter lesions in multiple sclerosis. While 7T FLAIR is effective in detecting cortical lesions, it has not been fully optimized for visualization of white matter lesions and thus has not been used for delineating lesions in quantitative magnetic resonance imaging (MRI) studies of the normal appearing white matter in multiple sclerosis. Therefore, we aimed to evaluate the sensitivity of 7T magnetization-transfer-weighted (MTw ) images in the detection of white matter lesions compared with 3T-FLAIR. Fifteen patients with clinically isolated syndrome, 6 with multiple sclerosis, and 10 healthy participants were scanned with 7T 3-dimensional (D) MTw and 3T-2D-FLAIR sequences on the same day. White matter lesions visible on either sequence were delineated. Of 662 lesions identified on 3T-2D-FLAIR images, 652 were detected on 7T-3D-MTw images (sensitivity, 98%; 95% confidence interval, 97% to 99%). The Spearman correlation coefficient between lesion loads estimated by the two sequences was .910. The intrarater and interrater reliability for 7T-3D-MTw images was good with an intraclass correlation coefficient (ICC) of 98.4% and 81.8%, which is similar to that for 3T-2D-FLAIR images (ICC 96.1% and 96.7%). Seven-Tesla MTw sequences detected most of the white matter lesions identified by FLAIR at 3T. This suggests that 7T-MTw imaging is a robust alternative for detecting demyelinating lesions in addition to 3T-FLAIR. Future studies need to compare the roles of optimized 7T-FLAIR and of 7T-MTw imaging. © 2017 The Authors. Journal of Neuroimaging published by Wiley Periodicals, Inc. on behalf of American Society of Neuroimaging.

  16. Fully automatic detection of deep white matter T1 hypointense lesions in multiple sclerosis.

    PubMed

    Spies, Lothar; Tewes, Anja; Suppa, Per; Opfer, Roland; Buchert, Ralph; Winkler, Gerhard; Raji, Alaleh

    2013-12-07

    A novel method is presented for fully automatic detection of candidate white matter (WM) T1 hypointense lesions in three-dimensional high-resolution T1-weighted magnetic resonance (MR) images. By definition, T1 hypointense lesions have similar intensity as gray matter (GM) and thus appear darker than surrounding normal WM in T1-weighted images. The novel method uses a standard classification algorithm to partition T1-weighted images into GM, WM and cerebrospinal fluid (CSF). As a consequence, T1 hypointense lesions are assigned an increased GM probability by the standard classification algorithm. The GM component image of a patient is then tested voxel-by-voxel against GM component images of a normative database of healthy individuals. Clusters (≥0.1 ml) of significantly increased GM density within a predefined mask of deep WM are defined as lesions. The performance of the algorithm was assessed on voxel level by a simulation study. A maximum dice similarity coefficient of 60% was found for a typical T1 lesion pattern with contrasts ranging from WM to cortical GM, indicating substantial agreement between ground truth and automatic detection. Retrospective application to 10 patients with multiple sclerosis demonstrated that 93 out of 96 T1 hypointense lesions were detected. On average 3.6 false positive T1 hypointense lesions per patient were found. The novel method is promising to support the detection of hypointense lesions in T1-weighted images which warrants further evaluation in larger patient samples.

  17. Computer-Aided Detection of Exophytic Renal Lesions on Non-Contrast CT Images

    PubMed Central

    Liu, Jianfei; Wang, Shijun; Linguraru, Marius George; Yao, Jianhua; Summers, Ronald M.

    2014-01-01

    Renal lesions are important extracolonic findings on computed tomographic colonography (CTC). They are difficult to detect on non-contrast CTC images due to low image contrast with surrounding objects. In this paper, we developed a novel computer-aided diagnosis system to detect a subset of renal lesions, exophytic lesions, by 1) exploiting efficient belief propagation to segment kidneys, 2) establishing an intrinsic manifold diffusion on kidney surface, 3) searching for potential lesion-caused protrusions with local maximum diffusion response, and 4) exploring novel shape descriptors, including multi-scale diffusion response, with machine learning to classify exophytic renal lesions. Experimental results on the validation dataset with 167 patients revealed that manifold diffusion significantly outperformed conventional shape features (p < 1e − 3) and resulted in 95% sensitivity with 15 false positives per patient for detecting exophytic renal lesions. Five-fold cross-validation also demonstrated that our method could stably detect exophytic renal lesions. These encouraging results demonstrated that manifold diffusion is a key means to enable accurate computer-aided diagnosis of renal lesions. PMID:25189363

  18. Haemophilus ducreyi detection by polymerase chain reaction in oesophageal lesions of HIV patients.

    PubMed

    Borges, M C; Colares, J K B; Lima, D M; Fonseca, B A L

    2009-04-01

    HIV patients frequently have opportunistic oesophageal infections. We report Haemophilus ducreyi genetic material detected by polymerase chain reaction in biopsies of oesophageal lesions in three HIV-1-infected patients. This finding may be an indication of its aetiopathological role in oesophageal lesions of HIV patients.

  19. Fully automatic detection of deep white matter T1 hypointense lesions in multiple sclerosis

    NASA Astrophysics Data System (ADS)

    Spies, Lothar; Tewes, Anja; Suppa, Per; Opfer, Roland; Buchert, Ralph; Winkler, Gerhard; Raji, Alaleh

    2013-12-01

    A novel method is presented for fully automatic detection of candidate white matter (WM) T1 hypointense lesions in three-dimensional high-resolution T1-weighted magnetic resonance (MR) images. By definition, T1 hypointense lesions have similar intensity as gray matter (GM) and thus appear darker than surrounding normal WM in T1-weighted images. The novel method uses a standard classification algorithm to partition T1-weighted images into GM, WM and cerebrospinal fluid (CSF). As a consequence, T1 hypointense lesions are assigned an increased GM probability by the standard classification algorithm. The GM component image of a patient is then tested voxel-by-voxel against GM component images of a normative database of healthy individuals. Clusters (≥0.1 ml) of significantly increased GM density within a predefined mask of deep WM are defined as lesions. The performance of the algorithm was assessed on voxel level by a simulation study. A maximum dice similarity coefficient of 60% was found for a typical T1 lesion pattern with contrasts ranging from WM to cortical GM, indicating substantial agreement between ground truth and automatic detection. Retrospective application to 10 patients with multiple sclerosis demonstrated that 93 out of 96 T1 hypointense lesions were detected. On average 3.6 false positive T1 hypointense lesions per patient were found. The novel method is promising to support the detection of hypointense lesions in T1-weighted images which warrants further evaluation in larger patient samples.

  20. P16(INK 4a) and Ki-67 expression in human papilloma virus-related head and neck mucosal lesions.

    PubMed

    Gültekin, Sibel Elif; Sengüven, Burcu; Klussmann, Jens Peter; Dienes, Hans Peter

    2015-03-01

    Human papilloma virus (HPV) is postulated as a risk factor in the etiology of some specific mucosal pathologies in the head and neck regions. Despite the frequent use of p16(INK4a) as a surrogate marker for HPV-infection, there is still controversy with respect to its reliability. This study has been undertaken to assess the potential role of p16(INK 4a) and Ki-67 expression in HPV-related lesions. The study was conducted on 71 specimens of oral, tonsillar and laryngeal lesions which comprised 25 dysplasia and 46 papilloma specimens. Specimens were immunohistochemically stained for p16(INK4A) and Ki-67 proteins. HPV DNA was determined by one step multiplex polymerase chain reaction. HPV DNA was detected in 33.8% of all lesions. Tonsil and larynx lesions showed significant differences with oral lesions for HPV positivity (p < 0.001). p16(INK 4a) over-expression was seen in 56.5% of papilloma and 60% of dysplasia specimens. HPV status showed a positive correlation with p16(INK 4a) expression in tonsillar dysplasias (p < 0.001). p16(INK 4a) expression may have a value as a marker in high risk HPV induced dysplasias, but not in low risk infected lesions. The proliferation index is not related to HPV-induced lesions and may be evaluated as an independent marker in head and neck premalignant lesions.

  1. Granulomatous Skin Lesions in Moray Eels Caused by a Novel Mycobacterium Species Related to Mycobacterium triplex

    PubMed Central

    Herbst, Lawrence H.; Costa, Sylvia F.; Weiss, Louis M.; Johnson, Linda K.; Bartell, John; Davis, Raymond; Walsh, Michael; Levi, Michael

    2001-01-01

    An outbreak of granulomatous dermatitis was investigated in a captive population of moray eels. The affected eels had florid skin nodules concentrated around the head and trunk. Histopathological examination revealed extensive granulomatous inflammation within the dermis and subcutaneous fascial plane between the fat and axial musculature. Acid-fast rods were detected within the smallest lesions, which were presumably the ones that had developed earliest. Eventually, after several months of incubation at room temperature, a very slowly growing acid-fast organism was isolated. Sequencing of the 16S rRNA gene identified it as a Mycobacterium species closely related (0.59% divergence) to M. triplex, an SAV mycobacterium. Intradermal inoculation of healthy green moray eels with this organism reliably reproduced the lesion. Experimentally induced granulomatous dermatitis appeared within 2 weeks of inoculation and slowly but progressively expanded during the 2 months of the experiment. Live organisms were recovered from these lesions at all time points, fulfilling Koch's postulates for this bacterium. In a retrospective study of tissues collected between 1993 and 1999 from five spontaneous disease cases, acid-fast rods were consistently found within lesions, and a nested PCR for the rRNA gene also demonstrated the presence of mycobacteria within affected tissues. PMID:11402008

  2. Structured learning algorithm for detection of nonobstructive and obstructive coronary plaque lesions from computed tomography angiography

    PubMed Central

    Kang, Dongwoo; Dey, Damini; Slomka, Piotr J.; Arsanjani, Reza; Nakazato, Ryo; Ko, Hyunsuk; Berman, Daniel S.; Li, Debiao; Kuo, C.-C. Jay

    2015-01-01

    Abstract. Visual identification of coronary arterial lesion from three-dimensional coronary computed tomography angiography (CTA) remains challenging. We aimed to develop a robust automated algorithm for computer detection of coronary artery lesions by machine learning techniques. A structured learning technique is proposed to detect all coronary arterial lesions with stenosis ≥25%. Our algorithm consists of two stages: (1) two independent base decisions indicating the existence of lesions in each arterial segment and (b) the final decision made by combining the base decisions. One of the base decisions is the support vector machine (SVM) based learning algorithm, which divides each artery into small volume patches and integrates several quantitative geometric and shape features for arterial lesions in each small volume patch by SVM algorithm. The other base decision is the formula-based analytic method. The final decision in the first stage applies SVM-based decision fusion to combine the two base decisions in the second stage. The proposed algorithm was applied to 42 CTA patient datasets, acquired with dual-source CT, where 21 datasets had 45 lesions with stenosis ≥25%. Visual identification of lesions with stenosis ≥25% by three expert readers, using consensus reading, was considered as a reference standard. Our method performed with high sensitivity (93%), specificity (95%), and accuracy (94%), with receiver operator characteristic area under the curve of 0.94. The proposed algorithm shows promising results in the automated detection of obstructive and nonobstructive lesions from CTA. PMID:26158081

  3. Breast Imaging Reporting and Data System Category 3 Lesions Detected on Whole-Breast Screening Ultrasound

    PubMed Central

    Nam, Sang Yu; Ko, Eun Young; Han, Boo-Kyung; Shin, Jung Hee; Hahn, Soo Yeon

    2016-01-01

    Purpose This study assessed the incidence and cancer rate of probably benign lesions detected on bilateral whole-breast screening ultrasound (US), which corresponded to US Breast Imaging Reporting and Data System (BI-RADS) category 3, and evaluated the proper management of those lesions. Methods This study was approved by the Institutional Review Board in our institution, which waived informed patient consent. We retrospectively reviewed US images of 1,666 patients who underwent bilateral whole-breast screening US as a supplemental screening test to negative screening mammography or screening US only. The incidence, clinical course, and cancer rate of screening US-detected probably benign lesions corresponding to US BI-RADS category 3 were investigated, and the size and multiplicity of screening US-detected category 3 lesions were evaluated. Results Probably benign lesions corresponding to US BI-RADS category 3 were detected in 689 of 1,666 patients (41.4%) who underwent screening US. Among them, 653 had follow-up US images for at least 24 months, and among these 653, 190 (29.1%) had multiple bilateral category 3 lesions. Moreover, 539 of 1,666 patients (32.4%) had lesions ≤1 cm in size and 114 of 1,666 (6.8%) had lesions >1 cm (median, 0.82 cm; range, 0.3–4.2 cm). Four of the 653 patients (0.6%) showed suspicious interval changes and were categorized into BI-RADS category 4. Biopsy analysis confirmed only one lesion as invasive ductal carcinoma at the 6-month follow-up; another lesion was an intraductal papilloma and the remaining two were fibroadenomas. Overall cancer rate of the screening US-detected BI-RADS category 3 lesions was 0.2%. Conclusion The incidence of category 3 lesions detected on screening US only was very high, but the cancer rate was very low. Therefore, in an average-risk population, routine screening US is preferable over short-term follow-up for BI-RADS category 3 lesions detected on whole-breast screening US. PMID:27721880

  4. T1w dark blood imaging improves detection of contrast enhancing lesions in multiple sclerosis.

    PubMed

    Thaler, Christian; Schneider, Tanja; Sedlacik, Jan; Kutzner, Daniel; Stellmann, Jan-Patrick; Heesen, Christoph; Fiehler, Jens; Siemonsen, Susanne

    2017-01-01

    In multiple sclerosis (MS) the sensitivity for detection of contrast enhancing lesions (CEL) in T1-weighted scans is essential for diagnostics and therapy decisions. The purpose of our study was to evaluate the sensitivity of T1w MPRAGE scans in comparison to T1w dark blood technique (T1-DB) for CEL in MS. 3T MR imaging was performed in 37 MS patients, including T2-weighted imaging, T1w MPRAGE before and after gadolinium injection (unenhanced-T1 and T1-CE) and T1-DB imaging. After gadolinium application, the T1-DB scan was performed prior to T1-CE. From unenhanced-T1 and T1-CE scans, subtraction images (T1-SUB) were calculated. The number of CEL was determined separately on T1-CE and T1-DB by two raters independently. Lesions only detected on T1-DB scans then were verified on T1-SUB. Only lesions detected by both raters were included in further analysis. In 16 patients, at least one CEL was detected by both rater, either on T1-CE or T1-DB. All lesions that were detected on T1-CE were also detected on T1-DB images. The total number of contrast enhancing lesions detected on T1-DB images (n = 54) by both raters was significantly higher than the corresponding number of lesions identified on T1-CE (n = 27) (p = 0.01); all of these lesions could be verified on SUB images. In 21 patients, no CEL was detected in any of the sequences. The application of T1-DB technique increases the sensitivity for CEL in MS, especially for those lesions that show only subtle increase in intensity after Gadolinium application but remain hypo- or iso-intense to surrounding tissue.

  5. Image patch-based method for automated classification and detection of focal liver lesions on CT

    NASA Astrophysics Data System (ADS)

    Safdari, Mustafa; Pasari, Raghav; Rubin, Daniel; Greenspan, Hayit

    2013-03-01

    We developed a method for automated classification and detection of liver lesions in CT images based on image patch representation and bag-of-visual-words (BoVW). BoVW analysis has been extensively used in the computer vision domain to analyze scenery images. In the current work we discuss how it can be used for liver lesion classification and detection. The methodology includes building a dictionary for a training set using local descriptors and representing a region in the image using a visual word histogram. Two tasks are described: a classification task, for lesion characterization, and a detection task in which a scan window moves across the image and is determined to be normal liver tissue or a lesion. Data: In the classification task 73 CT images of liver lesions were used, 25 images having cysts, 24 having metastasis and 24 having hemangiomas. A radiologist circumscribed the lesions, creating a region of interest (ROI), in each of the images. He then provided the diagnosis, which was established either by biopsy or clinical follow-up. Thus our data set comprises 73 images and 73 ROIs. In the detection task, a radiologist drew ROIs around each liver lesion and two regions of normal liver, for a total of 159 liver lesion ROIs and 146 normal liver ROIs. The radiologist also demarcated the liver boundary. Results: Classification results of more than 95% were obtained. In the detection task, F1 results obtained is 0.76. Recall is 84%, with precision of 73%. Results show the ability to detect lesions, regardless of shape.

  6. Minimal intervention dentistry: part 4. Detection and diagnosis of initial caries lesions.

    PubMed

    Guerrieri, A; Gaucher, C; Bonte, E; Lasfargues, J J

    2012-12-01

    The detection of carious lesions is focused on the identification of early mineral changes to allow the demineralisation process to be managed by non-invasive interventions. The methods recommended for clinical diagnosis of initial carious lesions are discussed and illustrated. These include the early detection of lesions, evaluation of the extent of the lesion and its state of activity and the establishment of appropriate monitoring. The place of modern tools, including those based on fluorescence, is discussed. These can help inform patients. They are also potentially useful in regular control visits to monitor the progression or regression of early lesions. A rigorous and systematic approach to caries diagnosis is essential to establish a care plan for the disease and to identify preventive measures based on more precise diagnosis and to reduce reliance on restorative measures.

  7. Infiltration of natural caries lesions in relation to their activity status and acid pretreatment in vitro.

    PubMed

    Neuhaus, K W; Schlafer, S; Lussi, A; Nyvad, B

    2013-01-01

    This study aimed at testing how active and inactive enamel caries lesions differ by their degree of resin infiltration, and whether the choice of acid pretreatment plays a crucial role. Four examiners assessed 104 human molars and premolars with noncavitated enamel lesions and classified them as 'active' or 'inactive' using the Nyvad criteria. Forty-five teeth were included in this study after independent unanimous lesion activity assessment. Lesions were cut perpendicularly into 2 halves. Each half lesion was pretreated with either 15% hydrochloric acid or 35% phosphoric acid. The lesions were infiltrated after staining with rhodamine isothiocyanate. Thin sections of 100 µm were prepared and the specimens were bleached with 30% hydrogen peroxide. The specimens were then counterstained with sodium fluorescein, subjected to confocal laser scanning microscopy and analyzed quantitatively. Outcome parameters were maximum and average infiltration depths as well as relative penetration depths and areas. In active lesions no significant difference of percentage maximum penetration depth and percentage average penetration depth between lesions pretreated with hydrochloric or phosphoric acid could be observed. In inactive lesions, however, phosphoric acid pretreatment resulted in significantly lower penetration compared to hydrochloric acid pretreatment. Surface conditioning with hydrochloric acid led to similar infiltration results in active and inactive lesions. Moreover, inactive lesions showed greater variability in all assessed infiltration parameters than did active lesions. In conclusion, caries lesion activity and acid pretreatment both influenced the infiltration. The use of phosphoric acid to increase permeability of the surface layer of active lesions should be further explored.

  8. Melanoma and other skin lesion detection using smart handheld devices.

    PubMed

    Zouridakis, George; Wadhawan, Tarun; Situ, Ning; Hu, Rui; Yuan, Xiaojing; Lancaster, Keith; Queen, Courtney M

    2015-01-01

    Smartphones of the latest generation featuring advanced multicore processors, dedicated microchips for graphics, high-resolution cameras, and innovative operating systems provide a portable platform for running sophisticated medical screening software and delivering point-of-care patient diagnostic services at a very low cost. In this chapter, we present a smartphone digital dermoscopy application that can analyze high-resolution images of skin lesions and provide the user with feedback about the likelihood of malignancy. The same basic procedure has been adapted to evaluate other skin lesions, such as the flesh-eating bacterial disease known as Buruli ulcer. When implemented on the iPhone, the accuracy and speed achieved by this application are comparable to that of a desktop computer, demonstrating that smartphone applications can combine portability and low cost with high performance. Thus, smartphone-based systems can be used as assistive devices by primary care physicians during routine office visits, and they can have a significant impact in underserved areas and in developing countries, where health-care infrastructure is limited.

  9. [Does endoscopist fatigue play a role in incomplete colonoscopies and detection of polypoid lesions?].

    PubMed

    Borda, Fernando; Borda, Ana; Jiménez, Francisco Javier; Fernández-Urién, Ignacio; Vila, Juan José; Zozaya, José Manuel

    2014-01-01

    Nowadays, the possible effect of endoscopist fatigue on the results of colonoscopies is under discussion. We aimed to analyze possible differences in cecal intubation and the polyp and adenoma detection rate, depending on whether colonoscopies were performed at the beginning or at the end of the daily endoscopy session and to analyze the influence of the queue position on the detection rate. A retrospective study was performed with 1,000 ambulatory and consecutive colonoscopies, divided into 2 groups: «early» and «late» procedures. A total of 95 colonoscopies were excluded due to poor colon cleansing. After confirming that patient characteristics were homogenous in the two groups, we compared the frequency of complete colonoscopies and the polyp and adenoma detection rate. Possible differences between the 2 groups in the polyp detection rate according to the colonoscopy schedule were analyzed. The overall polyp and adenoma detection rates were 44.2 and 30.5%, respectively, with no significant differences among 13 different endoscopists; polyps: p = 0.21; adenomas: p=0.63. No significant differences were found between the «early group» (n= 532) and the «late group» (n = 373) in the rates of complete colonoscopies [97.2 vs 99.4% (p=0.92)], the polyp detection rate [45.9 vs 41.8% (p=0.23)], the adenoma detection rate [30.8 vs 30% (p=0.80)] or the serrated adenoma rate [2.1% vs 1.6% (p=0.62)]. The lesion detection rate did not vary in relation to the «queue position»: polyps [p = 0.60, and adenomas: p = 0.83. In our series, endoscopist fatigue at the end of the day had no influence on the complete colonoscopy rate or on the polyp and adenoma detection rate. There were no differences in the number of polypoid lesions detected according to the timing of the colonoscopy schedule. Copyright © 2013 Elsevier España, S.L. and AEEH y AEG. All rights reserved.

  10. Stress-related factors in the emergence of transient global amnesia with hippocampal lesions

    PubMed Central

    Döhring, Juliane; Schmuck, Alexander; Bartsch, Thorsten

    2014-01-01

    The transient global amnesia (TGA) is a rare amnesic syndrome that is characterized by an acute onset episode of an anterograde and retrograde amnesia. Its origin is still debated, but there is evidence for psychological factors involved in TGA. In neuroimaging, selective lesions in the CA1 field of the hippocampus can be detected, a region that is particularly involved in the processing of memory, stress and emotion. The aim of this study was to assess the role of psychological stress in TGA by studying the prevalence of stress related precipitating events and individual stress-related personality profiles as well as coping strategies in patients. The hypothesis of a functional differentiation of the hippocampus in mnemonic and stress-related compartments was also evaluated. From all 113 patients, 18% (n = 24) patients experienced emotional and psychological stress episodes directly before the TGA. In a cohort of 21 acute patients, TGA patients tend to cope with stress less efficiently and less constructively than controls. Patients who experienced a stress related precipitant event exhibited a higher level of anxiety in comparison to non-stress patients and controls. However, there was no difference between the general experience of stress and the number of stress inducing life events. The majority of patients (73%) did show typical magnetic resonance imaging (MRI) lesions in the CA1 region of the hippocampal cornu ammonis. There was no clear association between stressful events, distribution of hippocampal CA1 lesions and behavioral patterns during the TGA. Disadvantageous coping strategies and an elevated anxiety level may increase the susceptibility to psychological stress which may facilitate the pathophysiological cascade in TGA. The findings suggest a role of emotional stress factors in the manifestation of TGA in a subgroup of patients. Stress may be one trigger involved in the emergence of transient lesions in the hippocampal CA1 region, which are thought

  11. Advances in Optical Adjunctive Aids for Visualisation and Detection of Oral Malignant and Potentially Malignant Lesions

    PubMed Central

    Bhatia, Nirav; Lalla, Yastira; Vu, An N.; Farah, Camile S.

    2013-01-01

    Traditional methods of screening for oral potentially malignant disorders and oral malignancies involve a conventional oral examination with digital palpation. Evidence indicates that conventional examination is a poor discriminator of oral mucosal lesions. A number of optical aids have been developed to assist the clinician to detect oral mucosal abnormalities and to differentiate benign lesions from sinister pathology. This paper discusses advances in optical technologies designed for the detection of oral mucosal abnormalities. The literature regarding such devices, VELscope and Identafi, is critically analysed, and the novel use of Narrow Band Imaging within the oral cavity is also discussed. Optical aids are effective in assisting with the detection of oral mucosal abnormalities; however, further research is required to evaluate the usefulness of these devices in differentiating benign lesions from potentially malignant and malignant lesions. PMID:24078812

  12. Spinal focal lesion detection in multiple myeloma using multimodal image features

    NASA Astrophysics Data System (ADS)

    Fränzle, Andrea; Hillengass, Jens; Bendl, Rolf

    2015-03-01

    Multiple myeloma is a tumor disease in the bone marrow that affects the skeleton systemically, i.e. multiple lesions can occur in different sites in the skeleton. To quantify overall tumor mass for determining degree of disease and for analysis of therapy response, volumetry of all lesions is needed. Since the large amount of lesions in one patient impedes manual segmentation of all lesions, quantification of overall tumor volume is not possible until now. Therefore development of automatic lesion detection and segmentation methods is necessary. Since focal tumors in multiple myeloma show different characteristics in different modalities (changes in bone structure in CT images, hypointensity in T1 weighted MR images and hyperintensity in T2 weighted MR images), multimodal image analysis is necessary for the detection of focal tumors. In this paper a pattern recognition approach is presented that identifies focal lesions in lumbar vertebrae based on features from T1 and T2 weighted MR images. Image voxels within bone are classified using random forests based on plain intensities and intensity value derived features (maximum, minimum, mean, median) in a 5 x 5 neighborhood around a voxel from both T1 and T2 weighted MR images. A test data sample of lesions in 8 lumbar vertebrae from 4 multiple myeloma patients can be classified at an accuracy of 95% (using a leave-one-patient-out test). The approach provides a reasonable delineation of the example lesions. This is an important step towards automatic tumor volume quantification in multiple myeloma.

  13. Detection of helicobacter pylori in benign laryngeal lesions by polymerase chain reaction: a cross sectional study

    PubMed Central

    2012-01-01

    Background Although Helicobacter Pylori (HP) was detected in some cases of chronic laryngitis, the results were not confirmed by polymerase chain reaction (PCR). By this time, it has not been found in laryngeal lesions by in house PCR, the most sensitive method for detecting the genome tracks. Regarding the previous results and also few numbers of studies about the presence of HP in benign laryngeal lesions, specifically by PCR, we aimed to investigate the presence of HP in benign laryngeal lesions by in-house PCR. Methods The samples were taken from 55 patients with benign laryngeal lesions and frozen in −20°C. One milliliter (ml) of lysis buffer was added to 100 mg (mg) of each sample and the tube was placed in 56°C overnight. Then DNA extraction was carried out. Results To find HP DNA, in-house PCR was performed that revealed 5 positive results among 55 patients with benign laryngeal lesions. Of them, 3 were polyp, 1 was nodule and 1 was papilloma. Conclusion Although the number of positive results was not a lot in this study, it was in contrast with previous studies which could not find any HP tracks in benign laryngeal lesions by other methods. More studies about the prevalence of HP in benign laryngeal lesions improve judging about the effect of this infection on benign laryngeal lesions. PMID:22515206

  14. Improved Automatic Detection of New T2 Lesions in Multiple Sclerosis Using Deformation Fields.

    PubMed

    Cabezas, M; Corral, J F; Oliver, A; Díez, Y; Tintoré, M; Auger, C; Montalban, X; Lladó, M; Pareto, D; Rovira, À

    2016-06-09

    Detection of disease activity, defined as new/enlarging T2 lesions on brain MR imaging, has been proposed as a biomarker in MS. However, detection of new/enlarging T2 lesions can be hindered by several factors that can be overcome with image subtraction. The purpose of this study was to improve automated detection of new T2 lesions and reduce user interaction to eliminate inter- and intraobserver variability. Multiparametric brain MR imaging was performed at 2 time points in 36 patients with new T2 lesions. Images were registered by using an affine transformation and the Demons algorithm to obtain a deformation field. After affine registration, images were subtracted and a threshold was applied to obtain a lesion mask, which was then refined by using the deformation field, intensity, and local information. This pipeline was compared with only applying a threshold, and with a state-of-the-art approach relying only on image intensities. To assess improvements, we compared the results of the different pipelines with the expert visual detection. The multichannel pipeline based on the deformation field obtained a detection Dice similarity coefficient close to 0.70, with a false-positive detection of 17.8% and a true-positive detection of 70.9%. A statistically significant correlation (r = 0.81, P value = 2.2688e-09) was found between visual detection and automated detection by using our approach. The deformation field-based approach proposed in this study for detecting new/enlarging T2 lesions resulted in significantly fewer false-positives while maintaining most true-positives and showed a good correlation with visual detection annotations. This approach could reduce user interaction and inter- and intraobserver variability. © 2016 American Society of Neuroradiology.

  15. KRAS and BRAF mutations and MSI status in precursor lesions of colorectal cancer detected by colonoscopy.

    PubMed

    Yamane, L S; Scapulatempo-Neto, C; Alvarenga, L; Oliveira, C Z; Berardinelli, G N; Almodova, E; Cunha, T R; Fava, G; Colaiacovo, W; Melani, A; Fregnani, J H; Reis, R M; Guimarães, D P

    2014-10-01

    Colorectal cancer (CRC) is one of the most frequent cancers worldwide. Adenoma is the main precursor lesion and, recently, the serrated polyps were described as a group of colorectal lesions with malignant potential. The morphologic and biologic characterizations of serrated polyps remain limited. The aim of the present study was to determine the frequency of KRAS and BRAF mutations and microsatellite instability (MSI) in CRC precursor lesions, to evaluate the association between molecular, pathologic and morphologic alterations in precursor lesions and to compare with the alterations detected in CRC. A series of 342 precursor lesions were removed from 155 patients during colonoscopy. After morphologic classification, molecular analysis was performed in 103 precursor lesions, and their genetic profile compared with 47 sporadic CRCs. Adenomas were the main precursor lesions (70.2%). Among the serrated polyps, the main precursor lesion was hyperplastic polyps (HPs) (82.4%), followed by sessile serrated adenomas (12.7%) and traditional serrated adenomas (2.0%). KRAS mutations were detected in 13.6% of the precursor lesions, namely in adenomas and in HPs, but in no serrated adenoma. BRAF mutations were found in 9 (8.7%) precursor lesions, mainly associated with serrated polyps and absent in adenomas (P<0.001). High MSI (MSI-H) was absent in precursor lesions. In the 47 CCR cases, 46.8% exhibited KRAS mutation, 6.5% BRAF mutations and 10.6% MSI-H. This study confirms the role of KRAS and BRAF mutations in CRC carcinogenesis, a crucial step in implementing CRC screening strategies.

  16. Automated detection of colorectal lesions with dual-energy CT colonography

    NASA Astrophysics Data System (ADS)

    Näppi, Janne J.; Kim, Se Hyung; Yoshida, Hiroyuki

    2012-03-01

    Conventional single-energy computed tomography colonography (CTC) tends to miss polyps 6 - 9 mm in size and flat lesions. Dual-energy CTC (DE-CTC) provides more complete information about the chemical composition of tissue than does conventional CTC. We developed an automated computer-aided detection (CAD) scheme for detecting colorectal lesions in which dual-energy features were used to identify different bowel materials and their partial-volume artifacts. Based on these features, the dual-energy CAD (DE-CAD) scheme extracted the region of colon by use of a lumen-tracking method, detected lesions by use of volumetric shape features, and reduced false positives by use of a statistical classifier. For validation, 20 patients were prepared for DE-CTC by use of reduced bowel cleansing and orally administered fecal tagging with iodine and/or barium. The DE-CTC was performed in dual positions by use of a dual-energy CT scanner (SOMATOM Definition, Siemens) at 140 kVp and 80 kVp energy levels. The lesions identified by subsequent same-day colonoscopy were correlated with the DE-CTC data. The detection accuracies of the DE-CAD and conventional CAD schemes were compared by use of leave-one-patient-out evaluation and a bootstrap analysis. There were 25 colonoscopy-confirmed lesions: 22 were 6 - 9 mm and 3 were flat lesions >=10 mm in size. The DE-CAD scheme detected the large flat lesions and 95% of the 6 - 9 mm lesions with 9.9 false positives per patient. The improvement in detection accuracy by the DE-CAD was statistically significant.

  17. Dual-energy computed tomography for the detection of focal liver lesions.

    PubMed

    Lago, K N; Vallejos, J; Capuñay, C; Salas, E; Reynoso, E; Carpio, J B; Carrascosa, P M

    To qualitatively and quantitatively explore the spectral study of focal liver lesions, comparing it with the usual polychromatic assessment with single-energy computed tomography. We prospectively studied 50 patients with at least one focal liver lesion who were referred for abdominal multidetector computed tomography with intravenous contrast material. The portal phase was acquired with dual energy sources. The density of the lesions and of the surrounding liver parenchyma was measured both in the baseline polychromatic acquisition and in the posterior monochromatic reconstructions at 40 keV, 70 keV, and 140 keV. Spectral curves were traced and the dual-energy indices and contrast-to-noise ratio were calculated. Lastly, the quality of the images and the detectability of the lesions were assessed qualitatively. Densitometric differences between the different types of lesions (avascular and vascularized) and the liver were greater at low energy levels (left side of the spectral curve) than in the polychromatic evaluation. In the subjective assessment, the 40keV energy level had the greatest lesion detectability. Monochromatic spectral study with dual-energy computed tomography provides better lesion detectability at 40keV compared to that provided by the ordinary polychromatic evaluation. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Automatic detection of significant and subtle arterial lesions from coronary CT angiography

    NASA Astrophysics Data System (ADS)

    Kang, Dongwoo; Slomka, Piotr; Nakazato, Ryo; Cheng, Victor Y.; Min, James K.; Li, Debiao; Berman, Daniel S.; Kuo, C.-C. Jay; Dey, Damini

    2012-02-01

    Visual analysis of three-dimensional (3D) Coronary Computed Tomography Angiography (CCTA) remains challenging due to large number of image slices and tortuous character of the vessels. We aimed to develop an accurate, automated algorithm for detection of significant and subtle coronary artery lesions compared to expert interpretation. Our knowledge-based automated algorithm consists of centerline extraction which also classifies 3 main coronary arteries and small branches in each main coronary artery, vessel linearization, lumen segmentation with scan-specific lumen attenuation ranges, and lesion location detection. Presence and location of lesions are identified using a multi-pass algorithm which considers expected or "normal" vessel tapering and luminal stenosis from the segmented vessel. Expected luminal diameter is derived from the scan by automated piecewise least squares line fitting over proximal and mid segments (67%) of the coronary artery, considering small branch locations. We applied this algorithm to 21 CCTA patient datasets, acquired with dual-source CT, where 7 datasets had 17 lesions with stenosis greater than or equal to 25%. The reference standard was provided by visual and quantitative identification of lesions with any >=25% stenosis by an experienced expert reader. Our algorithm identified 16 out of the 17 lesions confirmed by the expert. There were 16 additional lesions detected (average 0.13/segment); 6 out of 16 of these were actual lesions with <25% stenosis. On persegment basis, sensitivity was 94%, specificity was 86% and accuracy was 87%. Our algorithm shows promising results in the high sensitivity detection and localization of significant and subtle CCTA arterial lesions.

  19. Detecting Secondary Caries Lesions: A Systematic Review and Meta-analysis.

    PubMed

    Brouwer, F; Askar, H; Paris, S; Schwendicke, F

    2016-02-01

    Secondary caries lesions are the main late complication of dental restorations, limiting their life span and generating costs by repeated reinterventions. Accurate detection of secondary lesions is crucial for estimating the true burden of the disease and allocating appropriate treatments. We aimed to assess the accuracy of detection methods for secondary caries lesions. Clinical or in vitro studies were included that investigated the accuracy of 5 detection methods--visual, tactile, radiography, laser fluorescence, quantitative light-induced fluorescence--of natural or artificially induced secondary lesions, as verified against an established reference test. Sensitivity, specificity, positive and negative likelihood ratios, as well as diagnostic odds ratios were calculated and publication bias assessed. From 1,179 screened studies, 23 were included. Most studies were performed in vitro, on permanent posterior teeth, and had high risk of bias or applicability concerns. Lesions were on proximal (14 studies) or other surfaces and adjacent to amalgam (16 studies) or tooth-colored materials. Visual (n = 11), radiographic (n = 13), and laser fluorescence detection (n = 8) had similar sensitivities (0.50 to 0.59) and specificities (0.78 to 0.83), with visual and laser fluorescence assessment being more accurate on nonproximal surfaces and adjacent to composites, respectively. Tactile assessment (n = 7) had low accuracy. Light-induced fluorescence (n = 3) was sensitive on nonproximal surfaces but had low specificities. Most analyses seemed to suffer from publication bias. Despite being a significant clinical and dental public health problem, detection of secondary caries lesions has been assessed by only a few studies with limited validity and applicability. Visual, radiographic and laser-fluorescence detection might be useful to detect secondary lesions. The validity of tactile assessment and quantitative light-induced fluorescence remains unclear at present.

  20. The prevalence, distribution and severity of detectable pathological lesions in badgers naturally infected with Mycobacterium bovis.

    PubMed

    Jenkins, H E; Morrison, W I; Cox, D R; Donnelly, C A; Johnston, W T; Bourne, F J; Clifton-Hadley, R S; Gettinby, G; McInerney, J P; Watkins, G H; Woodroffe, R

    2008-10-01

    The Randomized Badger Culling Trial (RBCT) began in 1998 to determine the impact of badger culling in controlling bovine tuberculosis in cattle. A total of 1166 badgers (14% of total) proactively culled during the RBCT were found to be tuberculous, offering a unique opportunity to study the pathology caused by Mycobacterium bovis in a large sample of badgers. Of these, 39% of adults (approximately 6% of all adults culled) had visible lesions (detectable at necropsy) of bovine tuberculosis; cubs had a lower prevalence of infection (9%) but a higher percentage of tuberculous cubs (55.5%) had visible lesions. Only approximately 1% of adult badgers had extensive, severe pathology. Tuberculous badgers with recorded bite wounds (approximately 5%) had a higher prevalence of visible lesions and a different distribution of lesions, suggesting transmission via bite wounds. However, the predominance of lesions in the respiratory tract indicates that most transmission occurs by the respiratory route.

  1. Detection of blunt, sharp force and gunshot lesions on burnt remains: a cautionary note.

    PubMed

    Poppa, Pasquale; Porta, Davide; Gibelli, Daniele; Mazzucchi, Alessandra; Brandone, Alberto; Grandi, Marco; Cattaneo, Cristina

    2011-09-01

    The study of skin and bone lesions may give information concerning type and manner of production, but in burnt material modification of tissues by the high temperatures may considerably change the morphological characteristics of the lesions. This study aims at pointing out the effects of burning head of pigs with several types of lesions (blunt trauma, sharp force, and gunshot lesions) on soft tissues and bones, both from a morphological and chemical point of view. Results show that the charring process does not completely destroy signs of lesions on bones, which can often be recovered by cleaning bone surface from charred soft-tissue residues. Furthermore, neutron activation analysis test proved that antimony may be detectable also on gunshot entry wounds at the final stages of charring process.

  2. Enhanced detection of dentinal lesions in OCT images using the RKT transformation

    NASA Astrophysics Data System (ADS)

    Kang, Hobin; Darling, Cynthia L.; Tom, Henry; Fried, Daniel

    2015-02-01

    Several studies have shown that optical coherence tomography (OCT) can be used to measure the remaining enamel thickness and detect the location of subsurface lesions hidden under the sound enamel. The purpose of this study was to develop algorithms to enhance the visibility of subsurface structures such as hidden occlusal lesions and the dentinal-enamel junction. Extracted teeth with natural occlusal lesions were imaged with OCT with and without added high index fluids. A Rotating Kernel Transformation (RKT) nonlinear image processing filter was applied to PS-OCT images to enhance the visibility of the subsurface lesions under the sound enamel. The filter significantly increased (P<0.05) the visibility of the subsurface lesions.

  3. Simulations of lesion detection using a combined phased array LHMI-technique.

    PubMed

    Heikkilä, Janne; Hynynen, Kullervo

    2008-11-01

    Ultrasound based elasticity imaging techniques have been developed during the past decades. Some of these techniques are based on an internal radiation force stimulation in which a transient or dynamic radiation force is produced by using a single or dual-frequency sonication. In addition, sonication and data acquisition can be implemented using combined or separate transducers. In this simulation study of lesion detection using localized harmonic motion imaging (LHMI), we used a combined phased array designed for simultaneous thermal ablation and lesion detection. In the sonication mode, a focused single-frequency amplitude-modulated sonication is used to induce harmonic motion and in the tracking mode, some of the array elements are used for pulse-echo tracking of the induced displacements. The results showed that the size of the lesion affected the induced displacement around the sonication point. The displacement tracking simulations demonstrated that these changes in the displacement distributions can be detected using only a few of the array elements in the tracking mode but the exact size of the lesion can not be detected accurately. The simulations also showed that two lesions having the radius of 2.5mm can be distinguished if distance between these lesions is at least 2.5mm.

  4. Long-term deficits in motion detection thresholds and spike count variability after unilateral vestibular lesion

    PubMed Central

    Yu, Xiong-Jie; Thomassen, Jakob S.; Dickman, J. David; Newlands, Shawn D.

    2014-01-01

    The vestibular system operates in a push-pull fashion using signals from both labyrinths and an intricate bilateral organization. Unilateral vestibular lesions cause well-characterized motor deficits that are partially compensated over time and whose neural correlates have been traced in the mean response modulation of vestibular nuclei cells. Here we compare both response gains and neural detection thresholds of vestibular nuclei and semicircular canal afferent neurons in intact vs. unilateral-lesioned macaques using three-dimensional rotation and translation stimuli. We found increased stimulus-driven spike count variability and detection thresholds in semicircular canal afferents, although mean responses were unchanged, after contralateral labyrinth lesion. Analysis of trial-by-trial spike count correlations of a limited number of simultaneously recorded pairs of canal afferents suggests increased noise correlations after lesion. In addition, we also found persistent, chronic deficits in rotation detection thresholds of vestibular nuclei neurons, which were larger in the ipsilesional than the contralesional brain stem. These deficits, which persisted several months after lesion, were due to lower rotational response gains, whereas spike count variability was similar in intact and lesioned animals. In contrast to persistent deficits in rotation threshold, translation detection thresholds were not different from those in intact animals. These findings suggest that, after compensation, a single labyrinth is sufficient to recover motion sensitivity and normal thresholds for the otolith, but not the semicircular canal, system. PMID:24848470

  5. Experimental evaluation of a simple lesion detection task with time-of-flight PET

    NASA Astrophysics Data System (ADS)

    Surti, S.; Karp, J. S.

    2009-01-01

    A new generation of high-performance, time-of-flight (TOF) PET scanners have recently been developed. In earlier works, the gain with TOF information was derived as a reduction of noise in the reconstructed image, or essentially a gain in scanner sensitivity. These derivations were applicable to analytical reconstruction techniques and 2D PET imaging. In this work, we evaluate the gain measured in the clinically relevant task of lesion detection with TOF information in fully 3D PET scanners using iterative reconstruction algorithms. We performed measurements in a fully 3D TOF PET scanner using spherical lesions in uniform, cylindrical phantom. Lesion detectability was estimated for 10 mm diameter lesions using a non-prewhitening matched filter signal-to-noise-ratio (NPW SNR) as the metric. Our results show that the use of TOF information leads to increased lesion detectability, which is achieved with less number of iterations of the reconstruction algorithm. These phantom results indicate that clinically, TOF PET will allow reduced scan times and improved lesion detectability, especially in large patients.

  6. Robust detection of multiple sclerosis lesions from intensity-normalized multi-channel MRI

    NASA Astrophysics Data System (ADS)

    Karpate, Yogesh; Commowick, Olivier; Barillot, Christian

    2015-03-01

    Multiple sclerosis (MS) is a disease with heterogeneous evolution among the patients. Quantitative analysis of longitudinal Magnetic Resonance Images (MRI) provides a spatial analysis of the brain tissues which may lead to the discovery of biomarkers of disease evolution. Better understanding of the disease will lead to a better discovery of pathogenic mechanisms, allowing for patient-adapted therapeutic strategies. To characterize MS lesions, we propose a novel paradigm to detect white matter lesions based on a statistical framework. It aims at studying the benefits of using multi-channel MRI to detect statistically significant differences between each individual MS patient and a database of control subjects. This framework consists in two components. First, intensity standardization is conducted to minimize the inter-subject intensity difference arising from variability of the acquisition process and different scanners. The intensity normalization maps parameters obtained using a robust Gaussian Mixture Model (GMM) estimation not affected by the presence of MS lesions. The second part studies the comparison of multi-channel MRI of MS patients with respect to an atlas built from the control subjects, thereby allowing us to look for differences in normal appearing white matter, in and around the lesions of each patient. Experimental results demonstrate that our technique accurately detects significant differences in lesions consequently improving the results of MS lesion detection.

  7. Initial assessment of image quality for low-dose PET: evaluation of lesion detectability

    NASA Astrophysics Data System (ADS)

    Schaefferkoetter, Joshua D.; Yan, Jianhua; Townsend, David W.; Conti, Maurizio

    2015-07-01

    In the context of investigating the potential of low-dose PET imaging for screening applications, we developed methods to assess small lesion detectability as a function of the number of counts in the scan. We present here our methods and preliminary validation using tuberculosis cases. FDG-PET data from seventeen patients presenting diffuse hyper-metabolic lung lesions were selected for the study, to include a wide range of lesion sizes and contrasts. Reduced doses were simulated by randomly discarding events in the PET list mode, and ten realizations at each simulated dose were generated and reconstructed. The data were grouped into 9 categories determined by the number of included true events, from  >40 M to  <250 k counts. The images reconstructed from the original full statistical set were used to identify lung lesions, and each was, at every simulated dose, quantified by 6 parameters: lesion metabolic volume, lesion-to-background contrast, mean lesion tracer uptake, standard deviation of activity measurements (across realizations), lesion signal-to-noise ratio (SNR), and Hotelling observer SNR. Additionally, a lesion-detection task including 550 images was presented to several experienced image readers for qualitative assessment. Human observer performances were ranked using receiver operating characteristic analysis. The observer results were correlated with the lesion image measurements and used to train mathematical observer models. Absolute sensitivities and specificities of the human observers, as well as the area under the ROC curve, showed clustering and performance similarities among images produced from 5 million or greater counts. The results presented here are from a clinically realistic but highly constrained experiment, and more work is needed to validate these findings with a larger patient population.

  8. B-Spline Filtering for Automatic Detection of Calcification Lesions in Mammograms

    SciTech Connect

    Bueno, G.; Ruiz, M.; Sanchez, S

    2006-10-04

    Breast cancer continues to be an important health problem between women population. Early detection is the only way to improve breast cancer prognosis and significantly reduce women mortality. It is by using CAD systems that radiologist can improve their ability to detect, and classify lesions in mammograms. In this study the usefulness of using B-spline based on a gradient scheme and compared to wavelet and adaptative filtering has been investigated for calcification lesion detection and as part of CAD systems. The technique has been applied to different density tissues. A qualitative validation shows the success of the method.

  9. B-Spline Filtering for Automatic Detection of Calcification Lesions in Mammograms

    NASA Astrophysics Data System (ADS)

    Bueno, G.; Sánchez, S.; Ruiz, M.

    2006-10-01

    Breast cancer continues to be an important health problem between women population. Early detection is the only way to improve breast cancer prognosis and significantly reduce women mortality. It is by using CAD systems that radiologist can improve their ability to detect, and classify lesions in mammograms. In this study the usefulness of using B-spline based on a gradient scheme and compared to wavelet and adaptative filtering has been investigated for calcification lesion detection and as part of CAD systems. The technique has been applied to different density tissues. A qualitative validation shows the success of the method.

  10. Optical configuration of pigmented lesion detection by frequency analysis of skin speckle patterns

    PubMed Central

    Bishitz, Yael; Ozana, Nisan; Schwarz, Ariel; Beiderman, Yevgeny; Garcia, Javier; Zalevsky, Zeev

    2016-01-01

    In this paper we present a novel approach of realizing a safe, simple, and inexpensive sensor applicable to pigmented lesions detection. The approach is based on temporal tracking of back-reflected secondary speckle patterns generated while illuminating the affected area with a laser and applying periodic pressure to the surface via a controlled vibration source. When applied to pigmented lesions, the technique is superior to visual examination in avoiding many false positives and resultant unnecessary biopsies. Applying a series of different vibration frequencies at the examined tissue and analyzing the 2-D time varying speckle patterns in response to the applied periodic pressure creates a unique signature for each and different pigmented lesion. Analyzing these signatures is the first step toward detection of malignant melanoma. In this paper we present preliminary experiments that show the validity of the developed sensor for the classification of pigmented lesions. PMID:27231603

  11. detecting multiple sclerosis lesions with a fully bioinspired visual attention model

    NASA Astrophysics Data System (ADS)

    Villalon-Reina, Julio; Gutierrez-Carvajal, Ricardo; Thompson, Paul M.; Romero-Castro, Eduardo

    2013-11-01

    The detection, segmentation and quantification of multiple sclerosis (MS) lesions on magnetic resonance images (MRI) has been a very active field for the last two decades because of the urge to correlate these measures with the effectiveness of pharmacological treatment. A myriad of methods has been developed and most of these are non specific for the type of lesions and segment the lesions in their acute and chronic phases together. On the other hand, radiologists are able to distinguish between several stages of the disease on different types of MRI images. The main motivation of the work presented here is to computationally emulate the visual perception of the radiologist by using modeling principles of the neuronal centers along the visual system. By using this approach we are able to detect the lesions in the majority of the images in our population sample. This type of approach also allows us to study and improve the analysis of brain networks by introducing a priori information.

  12. Incidentally detected breast lesions on chest CT with US correlation: a pictorial essay

    PubMed Central

    Son, Jung Hee; Jung, Hyun Kyung; Song, Jong Woon; Baek, Hye Jin; Doo, Kyung Won; Kim, Woogyeong; Kim, Yeon Mee; Kim, Woon Won; Lee, Jung Sun; Cho, Een Young

    2016-01-01

    With the increasing use of computed tomography (CT), incidental breast lesions are detected more frequently. When interpreting chest CT findings, it is important for radiologists to carefully review the breast to recognize any abnormal findings that could affect patient management. The purpose of this study is to discuss incidental breast lesions on chest CT with ultrasonography correlation that may be encountered in routine clinical practice. PMID:27707680

  13. Detection and Localization of Pre-Cancerous Lesions and Early Lung Cancer Using Tissue Autofluorescence.

    NASA Astrophysics Data System (ADS)

    Hung, Jaclyn Yip-Chan

    In this work, two different yet related hypotheses were tested by experimental means as follows: (i) pre-cancerous and non-invasive (early) lung cancer can be detected and localized using the fluorescence properties of tumour localizing drugs at non-photosensitizing doses to skin tissue; (ii) significant differences exist in laser-induced autofluorescence between normal, pre-cancerous and cancerous tissues such that these differences alone can be exploited to detect and delineate early lung cancer without using exogenous drug(s). Exogenous fluorescent tumour markers such as hematoporphyrin derivatives (e.g. Photofrin) have been used to enhance to detection of occult lung lesions. Photofrin is preferentially retained in tumor tissues compared to the surrounding normal tissues; it fluoresces at 630 nm and 690 nm when excited at -405 nm. Based on this principle several imaging and non-imaging devices have been developed. However, wider clinical applications were limited due to the skin photosensitivity property of Photofrin. We have postulated that this could be solved by employing a much lower dose of Photofrin (0.25 mg/kg) which was believed to be less photosensitizing to human patients. This postulate was experimentally tested by ratio fluorometry and early lung cancers were detected with no false negative results and no apparent skin photosensitivity. An important finding in this study was that the mechanism for detection of early cancer was mainly due to the differences in the green autofluorescence between normal and malignant tissues, rather than fluorescence of tumour localizing drug. This discovery led to the second postulate of this thesis that tissue autofluorescence alone can be exploited for the detection of early lung cancer. The results indicated that algorithm(s) could be developed to clearly delineate early lesions from the normal tissues. Several algorithms were then tested using a non-imaging ratio fluorometer device and a prototype imaging

  14. Prevalence of oral lesions in HIV patients related to CD4 cell count and viral load in a Venezuelan population.

    PubMed

    Bravo, Inés María; Correnti, María; Escalona, Laura; Perrone, Marianella; Brito, Aubert; Tovar, Vilma; Rivera, Helen

    2006-01-01

    To determine the prevalence of oral lesions in a HIV+ group of patients, related to CD4 cell count and viral load in a Venezuelan population. In the present study, we evaluated 75 HIV+ adult patients, attended at the Center of Infectious Diseases, at the Faculty of Dentistry, Central University of Venezuela. Each patient was clinically examined for detection of oral mucosal lesions. In addition, CD4 cell count was determined by flow cytometry, as well as viral load by RT-PCR (Amplicor HIV-RNA, TM test 1.5, Roche). 85% (64/75) of HIV/AIDS patients showed associated HIV lesions. Oral Candidiasis constituted the most common lesion representing a 61% (39/64), followed by Oral Hairy Leukoplakia 53% (34/64); Oral Leukoplakia 34% (22/64), Melanic Hyperpigmentation 38% (18/64); Papilloma 13 (6/64), Lineal Gingival Erythema 8% (5/64); Aphtous Recurrent Stomatitis 5% (4/64) and Kaposi's Sarcoma 5% (3/64). Only one case of the following lesions were represented by Non Hodgkin Lymphoma, Multifocal Epithelial Hyperplasia, Recurrent Herpes, Histoplasmosis and Molluscum Contagiosum. The patients with a viral load of 30.000 copies/mm3 exhibited oral lesions related with HIV, independent of CD4 cell count, although patients with CD4+ levels of 200 cel/mm3 were more susceptible to develop these lesions. The most common oral lesion was Oral Candidiasis followed by Oral Hairy Leukoplakia, Oral Leukoplakia and Melanic Hyperpigmentation. A high viral load was strongly associated to the oral lesions occurrence independently of CD4+ cell count.

  15. Effect of Cortical Bone Thickness on Detection of Intraosseous Lesions by Ultrasonography

    PubMed Central

    Adibi, Sadaf; Shakibafard, Alireza; Karimi Sarvestani, Zohreh; Saadat, Najmeh; Khojastepour, Leila

    2015-01-01

    Background. Usefulness of ultrasound (US) in detection of intrabony lesions has been showed. A cortical bone perforation or a very thin and intact cortical bone is prerequisite for this purpose. Objective. The current in vitro study was aimed at measuring the cut-off thickness of the overlying cortical bone which allows ultrasonic assessment of bony defects. Materials and Methods. 20 bovine scapula blocks were obtained. Samples were numbered from 1 to 20. In each sample, 5 artificial lesions were made. The lesions were made in order to increase the overlying bone thickness, from 0.1 mm in the first sample to 2 mm in the last one (with 0.1 mm interval). After that, the samples underwent ultrasound examinations by two practicing radiologists. Results. All five lesions in samples numbered 1 to 11 were detected as hypoechoic area. Cortical bone thickness more than 1.1 mm resulted in a failure in the detection of central lesions. Conclusion. We can conclude that neither bony perforation nor very thin cortical bones are needed to consider US to be an effective imaging technique in the evaluation of bony lesion. PMID:26366296

  16. Molecular assays for detecting Aphanomyces invadans in ulcerative mycotic fish lesions.

    PubMed

    Vandersea, Mark W; Litaker, R Wayne; Yonnish, Bryan; Sosa, Emilio; Landsberg, Jan H; Pullinger, Chris; Moon-Butzin, Paula; Green, Jason; Morris, James A; Kator, Howard; Noga, Edward J; Tester, Patricia A

    2006-02-01

    The pathogenic oomycete Aphanomyces invadans is the primary etiological agent in ulcerative mycosis, an ulcerative skin disease caused by a fungus-like agent of wild and cultured fish. We developed sensitive PCR and fluorescent peptide nucleic acid in situ hybridization (FISH) assays to detect A. invadans. Laboratory-challenged killifish (Fundulus heteroclitus) were first tested to optimize and validate the assays. Skin ulcers of Atlantic menhaden (Brevoortia tyrannus) from populations found in the Pamlico and Neuse River estuaries in North Carolina were then surveyed. Results from both assays indicated that all of the lesioned menhaden (n = 50) collected in September 2004 were positive for A. invadans. Neither the FISH assay nor the PCR assay cross-reacted with other closely related oomycetes. These results provided strong evidence that A. invadans is the primary oomycete pathogen in ulcerative mycosis and demonstrated the utility of the assays. The FISH assay is the first molecular assay to provide unambiguous visual confirmation that hyphae in the ulcerated lesions were exclusively A. invadans.

  17. Molecular Assays for Detecting Aphanomyces invadans in Ulcerative Mycotic Fish Lesions

    PubMed Central

    Vandersea, Mark W.; Litaker, R. Wayne; Yonnish, Bryan; Sosa, Emilio; Landsberg, Jan H.; Pullinger, Chris; Moon-Butzin, Paula; Green, Jason; Morris, James A.; Kator, Howard; Noga, Edward J.; Tester, Patricia A.

    2006-01-01

    The pathogenic oomycete Aphanomyces invadans is the primary etiological agent in ulcerative mycosis, an ulcerative skin disease caused by a fungus-like agent of wild and cultured fish. We developed sensitive PCR and fluorescent peptide nucleic acid in situ hybridization (FISH) assays to detect A. invadans. Laboratory-challenged killifish (Fundulus heteroclitus) were first tested to optimize and validate the assays. Skin ulcers of Atlantic menhaden (Brevoortia tyrannus) from populations found in the Pamlico and Neuse River estuaries in North Carolina were then surveyed. Results from both assays indicated that all of the lesioned menhaden (n = 50) collected in September 2004 were positive for A. invadans. Neither the FISH assay nor the PCR assay cross-reacted with other closely related oomycetes. These results provided strong evidence that A. invadans is the primary oomycete pathogen in ulcerative mycosis and demonstrated the utility of the assays. The FISH assay is the first molecular assay to provide unambiguous visual confirmation that hyphae in the ulcerated lesions were exclusively A. invadans. PMID:16461710

  18. Model-Based Iterative Reconstruction Versus Adaptive Statistical Iterative Reconstruction and Filtered Back Projection in Liver 64-MDCT: Focal Lesion Detection, Lesion Conspicuity, and Image Noise

    PubMed Central

    Shuman, William P.; Green, Doug E.; Busey, Janet M.; Kolokythas, Orpheus; Mitsumori, Lee M.; Koprowicz, Kent M.; Thibault, Jean-Baptiste; Hsieh, Jiang; Alessio, Adam M.; Choi, Eunice; Kinahan, Paul E.

    2017-01-01

    OBJECTIVE The purpose of this study is to compare three CT image reconstruction algorithms for liver lesion detection and appearance, subjective lesion conspicuity, and measured noise. MATERIALS AND METHODS Thirty-six patients with known liver lesions were scanned with a routine clinical three-phase CT protocol using a weight-based noise index of 30 or 36. Image data from each phase were reconstructed with filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR), and model-based iterative reconstruction (MBIR). Randomized images were presented to two independent blinded reviewers to detect and categorize the appearance of lesions and to score lesion conspicuity. Lesion size, lesion density (in Hounsfield units), adjacent liver density (in Hounsfield units), and image noise were measured. Two different unblinded truth readers established the number, appearance, and location of lesions. RESULTS Fifty-one focal lesions were detected by truth readers. For blinded reviewers compared with truth readers, there was no difference for lesion detection among the reconstruction algorithms. Lesion appearance was statistically the same among the three reconstructions. Although one reviewer scored lesions as being more conspicuous with MBIR, the other scored them the same. There was significantly less background noise in air with MBIR (mean [± SD], 2.1 ± 1.4 HU) than with ASIR (8.9 ± 1.9 HU; p < 0.001) or FBP (10.6 ± 2.6 HU; p < 0.001). Mean lesion contrast-to-noise ratio was statistically significantly higher for MBIR (34.4 ± 29.1) than for ASIR (6.5 ± 4.9; p < 0.001) or FBP (6.3 ± 6.0; p < 0.001). CONCLUSION In routine-dose clinical CT of the liver, MBIR resulted in comparable lesion detection, lesion characterization, and subjective lesion conspicuity, but significantly lower background noise and higher contrast-to-noise ratio compared with ASIR or FBP. This finding suggests that further investigation of the use of MBIR to enable dose

  19. Fluorescence-Based Methods for Detecting Caries Lesions: Systematic Review, Meta-Analysis and Sources of Heterogeneity

    PubMed Central

    Gimenez, Thais; Braga, Mariana Minatel; Raggio, Daniela Procida; Deery, Chris; Ricketts, David N.; Mendes, Fausto Medeiros

    2013-01-01

    Background Fluorescence-based methods have been proposed to aid caries lesion detection. Summarizing and analysing findings of studies about fluorescence-based methods could clarify their real benefits. Objective We aimed to perform a comprehensive systematic review and meta-analysis to evaluate the accuracy of fluorescence-based methods in detecting caries lesions. Data Source Two independent reviewers searched PubMed, Embase and Scopus through June 2012 to identify papers/articles published. Other sources were checked to identify non-published literature. Study Eligibility Criteria, Participants and Diagnostic Methods The eligibility criteria were studies that: (1) have assessed the accuracy of fluorescence-based methods of detecting caries lesions on occlusal, approximal or smooth surfaces, in both primary or permanent human teeth, in the laboratory or clinical setting; (2) have used a reference standard; and (3) have reported sufficient data relating to the sample size and the accuracy of methods. Study Appraisal and Synthesis Methods A diagnostic 2×2 table was extracted from included studies to calculate the pooled sensitivity, specificity and overall accuracy parameters (Diagnostic Odds Ratio and Summary Receiver-Operating curve). The analyses were performed separately for each method and different characteristics of the studies. The quality of the studies and heterogeneity were also evaluated. Results Seventy five studies met the inclusion criteria from the 434 articles initially identified. The search of the grey or non-published literature did not identify any further studies. In general, the analysis demonstrated that the fluorescence-based method tend to have similar accuracy for all types of teeth, dental surfaces or settings. There was a trend of better performance of fluorescence methods in detecting more advanced caries lesions. We also observed moderate to high heterogeneity and evidenced publication bias. Conclusions Fluorescence-based devices

  20. Confocal fluorescence microscopy for detection of cervical preneoplastic lesions

    NASA Astrophysics Data System (ADS)

    Sheikhzadeh, Fahime; Ward, Rabab K.; Carraro, Anita; Chen, Zhaoyang; van Niekerk, Dirk; MacAulay, Calum; Follen, Michele; Lane, Pierre; Guillaud, Martial

    2015-03-01

    We examined and established the potential of ex-vivo confocal fluorescence microscopy for differentiating between normal cervical tissue, low grade Cervical Intraepithelial Neoplasia (CIN1), and high grade CIN (CIN2 and CIN3). Our objectives were to i) use Quantitative Tissue Phenotype (QTP) analysis to quantify nuclear and cellular morphology and tissue architecture in confocal microscopic images of fresh cervical biopsies and ii) determine the accuracy of high grade CIN detection via confocal microscopy. Cervical biopsy specimens of colposcopically normal and abnormal tissues obtained from 15 patients were evaluated by confocal fluorescence microscopy. Confocal images were analyzed and about 200 morphological and architectural features were calculated at the nuclear, cellular, and tissue level. For the purpose of this study, we used four features to delineate disease grade including nuclear size, cell density, estimated nuclear-cytoplasmic (ENC) ratio, and the average of three nearest Delaunay neighbors distance (3NDND). Our preliminary results showed ENC ratio and 3NDND correlated well with histopathological diagnosis. The Spearman correlation coefficient between each of these two features and the histopathological diagnosis was higher than the correlation coefficient between colposcopic appearance and histopathological diagnosis. Sensitivity and specificity of ENC ratio for detecting high grade CIN were both equal to 100%. QTP analysis of fluorescence confocal images shows the potential to discriminate high grade CIN from low grade CIN and normal tissues. This approach could be used to help clinicians identify HGSILs in clinical settings.

  1. Automatic segmentation of lesions for the computer-assisted detection in fluorescence urology

    NASA Astrophysics Data System (ADS)

    Kage, Andreas; Legal, Wolfgang; Kelm, Peter; Simon, Jörg; Bergen, Tobias; Münzenmayer, Christian; Benz, Michaela

    2012-03-01

    Bladder cancer is one of the most common cancers in the western world. The diagnosis in Germany is based on the visual inspection of the bladder. This inspection performed with a cystoscope is a challenging task as some kinds of abnormal tissues do not differ much in their appearance from their surrounding healthy tissue. Fluorescence Cystoscopy has the potential to increase the detection rate. A liquid marker introduced into the bladder in advance of the inspection is concentrated in areas with high metabolism. Thus these areas appear as bright "glowing". Unfortunately, the fluorescence image contains besides the glowing of the suspicious lesions no more further visual information like for example the appearance of the blood vessels. A visual judgment of the lesion as well as a precise treatment has to be done using white light illumination. Thereby, the spatial information of the lesion provided by the fluorescence image has to be guessed by the clinical expert. This leads to a time consuming procedure due to many switches between the modalities and increases the risk of mistreatment. We introduce an automatic approach, which detects and segments any suspicious lesion in the fluorescence image automatically once the image was classified as a fluorescence image. The area of the contour of the detected lesion is transferred to the corresponding white light image and provide the clinical expert the spatial information of the lesion. The advantage of this approach is, that the clinical expert gets the spatial and the visual information of the lesion together in one image. This can save time and decrease the risk of an incomplete removal of a malign lesion.

  2. Magnetic resonance diffusion tensor imaging for occult lesion detection in multiple sclerosis

    PubMed Central

    Chen, Jiafeng; Zhou, Chunkui; Zhu, Lijun; Yan, Xiuli; Wang, Yonghong; Chen, Xin; Fang, Shaokuan

    2017-01-01

    It remains challenging to locate occult lesions in patients with multiple sclerosis (MS). Diffusion tensor imaging (DTI) has been demonstrated to have the potential to identify occult changes in MS lesions. The present study used 3.0T magnetic resonance DTI to investigate the characteristics of different stages of MS lesions. DTI parameters, fractional anisotropy (FA), mean diffusivity (MD), λ// and λ┴ values of lesions were compared at the different stages of 10 patients with MS with 10 normal controls. The results demonstrated that FA and λ// values of MS silent and subacute lesions are decreased and MD and λ┴ values are increased, as compared with those of normal appearing white matter (NAWM) and normal controls. NAWM FA values were lower, and MD, λ//, and λ┴ values were higher than those of normal controls. It was also indicated that MS lesions had reduced color signals compared with the controls, and the lesion area appeared larger using DTI as compared with diffusion-weighted imaging. Furthermore, fiber abnormalities were detected in MS lesions using DTT, with fewer fibers connected to the lesion side, as compared with the contralateral side. FA, MD, λ// and λ┴ values in the thalamus were increased, as compared with those of normal controls (P<0.05); whereas MD, λ// and λ┴ values were significantly increased and FA values significantly decreased in the caudate nucleus and deep brain gray matter (DBGM) of patients with MS, as compared with the controls (P<0.05). λ// and λ┴ values were also significantly increased in the DBGM of patients with MS as compared with normal controls (P<0.05). The present findings demonstrate that DTI may be useful in the characterization of MS lesions. PMID:28123474

  3. Magnetic resonance diffusion tensor imaging for occult lesion detection in multiple sclerosis.

    PubMed

    Chen, Jiafeng; Zhou, Chunkui; Zhu, Lijun; Yan, Xiuli; Wang, Yonghong; Chen, Xin; Fang, Shaokuan

    2017-01-01

    It remains challenging to locate occult lesions in patients with multiple sclerosis (MS). Diffusion tensor imaging (DTI) has been demonstrated to have the potential to identify occult changes in MS lesions. The present study used 3.0T magnetic resonance DTI to investigate the characteristics of different stages of MS lesions. DTI parameters, fractional anisotropy (FA), mean diffusivity (MD), λ// and λ┴ values of lesions were compared at the different stages of 10 patients with MS with 10 normal controls. The results demonstrated that FA and λ// values of MS silent and subacute lesions are decreased and MD and λ┴ values are increased, as compared with those of normal appearing white matter (NAWM) and normal controls. NAWM FA values were lower, and MD, λ//, and λ┴ values were higher than those of normal controls. It was also indicated that MS lesions had reduced color signals compared with the controls, and the lesion area appeared larger using DTI as compared with diffusion-weighted imaging. Furthermore, fiber abnormalities were detected in MS lesions using DTT, with fewer fibers connected to the lesion side, as compared with the contralateral side. FA, MD, λ// and λ┴ values in the thalamus were increased, as compared with those of normal controls (P<0.05); whereas MD, λ// and λ┴ values were significantly increased and FA values significantly decreased in the caudate nucleus and deep brain gray matter (DBGM) of patients with MS, as compared with the controls (P<0.05). λ// and λ┴ values were also significantly increased in the DBGM of patients with MS as compared with normal controls (P<0.05). The present findings demonstrate that DTI may be useful in the characterization of MS lesions.

  4. [Method of automatic detection of brain lesion based on wavelet feature vector].

    PubMed

    Fan, Ya; Liu, Wei; Feng, Huanqing

    2011-06-01

    A new method of automatic detection of brain lesion based on wavelet feature vector of CT images has been proposed in the present paper. Firstly, we created training samples by manually segmenting normal CT images into gray matter, white matter and cerebrospinal fluid sub images. Then, we obtained the cluster centers using FCM clustering algorithm. When detecting lesions, the CT images to be detected was automatically segmented into sub images, with a certain degree of over-segmenting allowed under the premise of ensuring accuracy as much as possible. Then we extended these sub images and extracted the features to compute the distances with the cluster centers and to determine whether they belonged to the three kinds of normal samples, or, otherwise, belonged to lesions. The proposed method was verified by experiments.

  5. Hierarchical detection of red lesions in retinal images by multiscale correlation filtering

    NASA Astrophysics Data System (ADS)

    Zhang, Bob; Wu, Xiangqian; You, Jane; Li, Qin; Karray, Fakhri

    2009-02-01

    This paper presents an approach to the computer aided diagnosis (CAD) of diabetic retinopathy (DR) -- a common and severe complication of long-term diabetes which damages the retina and cause blindness. Since red lesions are regarded as the first signs of DR, there has been extensive research on effective detection and localization of these abnormalities in retinal images. In contrast to existing algorithms, a new approach based on Multiscale Correlation Filtering (MSCF) and dynamic thresholding is developed. This consists of two levels, Red Lesion Candidate Detection (coarse level) and True Red Lesion Detection (fine level). The approach was evaluated using data from Retinopathy On-line Challenge (ROC) competition website and we conclude our method to be effective and efficient.

  6. Detection and characterisation of papillomavirus in skin lesions of giraffe and sable antelope in South Africa.

    PubMed

    van Dyk, E; Bosman, A M; van Wilpe, E; Williams, J H; Bengis, R G; van Heerden, J; Venter, E H

    2011-06-01

    Papillomavirus was detected electron microscopically in cutaneous fibropapillomas of a giraffe (Giraffa camelopardalis) and a sable antelope (Hippotragus niger). The virus particles measured 45 nm in diameter. Histopathologically, the lesions showed histopathological features similar to those of equine sarcoid as well as positive immunoperoxidase-staining of tissue sections for papillomavirus antigen. Polymerase chain reaction (PCR) detected bovine papillomavirus (BPV) DNA. Bovine papillomavirus-1 was characterised by real-time PCR in the sable and giraffe, and cloning and sequencing of the PCR product revealed a similarity to BPV-1. As in the 1st giraffe, the lesions from a 2nd giraffe revealed locally malignant pleomorphism, possibly indicating the lesional end-point of papilloma infection. Neither virus particles nor positively staining papillomavirus antigen could be demonstrated in the 2nd giraffe but papillomavirus DNA was detected by real-time PCR which corresponded with BPV-1 and BPV-2.

  7. Effect of patient thickness and scan duration on lesion detectability in PET oncology imaging

    NASA Astrophysics Data System (ADS)

    Cheng, Phillip M.; Kinahan, Paul E.; Comtat, Claude; Lartizien, Carole; Lewellen, Thomas K.

    2005-04-01

    A dominant component of image quality for whole-body positron emission tomography (PET) imaging is attenuation, which is determined by patient thickness. This can be partially compensated for by adjusting scan duration. We evaluate the effect of changes in patient thickness and scan duration on lesion detection with model observers. We simulated 2D PET acquisitions of an anthropomorphic phantom with spherical target lesions. Three different anthropomorphic phantoms were used, with effective abdominal diameters of 20 cm, 27 cm, and 35 cm. The diameters of the lesions were varied from 1.0 to 3.0 cm, and the contrast ratios of the lesions were varied from 1.5 to 4.0. Noise-free scans were simulated with an analytical simulator. Poisson noise was added to simulate scan durations ranging from 1 to 10 minutes per bed position, using noise equivalent count rates previously measured using a modified NEMA NU2 countrate phantom. The average detectability of each target lesion under each condition was calculated using a non-prewhitening matched filter from 25 noisy realizations for each combination of parameters. Our results demonstrate the variation of the minimum scan duration required to detect a target of a given size and contrast ratio, for any fixed threshold of detectability. For image quality to remain constant for patients with larger cross-sectional areas, acquisition times should be increased accordingly, although in some cases this may not be possible due to practical constraints.

  8. Theoretical evaluation of the detectability of random lesions in bayesian emission reconstruction

    SciTech Connect

    Qi, Jinyi

    2003-05-01

    Detecting cancerous lesion is an important task in positron emission tomography (PET). Bayesian methods based on the maximum a posteriori principle (also called penalized maximum likelihood methods) have been developed to deal with the low signal to noise ratio in the emission data. Similar to the filter cut-off frequency in the filtered backprojection method, the prior parameters in Bayesian reconstruction control the resolution and noise trade-off and hence affect detectability of lesions in reconstructed images. Bayesian reconstructions are difficult to analyze because the resolution and noise properties are nonlinear and object-dependent. Most research has been based on Monte Carlo simulations, which are very time consuming. Building on the recent progress on the theoretical analysis of image properties of statistical reconstructions and the development of numerical observers, here we develop a theoretical approach for fast computation of lesion detectability in Bayesian reconstruction. The results can be used to choose the optimum hyperparameter for the maximum lesion detectability. New in this work is the use of theoretical expressions that explicitly model the statistical variation of the lesion and background without assuming that the object variation is (locally) stationary. The theoretical results are validated using Monte Carlo simulations. The comparisons show good agreement between the theoretical predications and the Monte Carlo results.

  9. Claspin as a biomarker of human papillomavirus-related high grade lesions of uterine cervix

    PubMed Central

    2012-01-01

    Background Claspin is a nuclear protein involved in DNA replication and damage response and is a key mediator for the S-phase checkpoint. Claspin expression is significantly high in several human solid tumors. Furthermore, high levels of claspin have been found in cervical cancer cell lines. Nevertheless, no data are available regarding claspin expression in cervical tissues. Methods In order to investigate whether claspin immunoreactivity is related to the lesion severity and High-Risk (HR) HPV infection, we analyzed claspin expression by immunohistochemistry in a series of cervical biopsies which represent the steps occurring during cervical carcinogenesis (normal tissues, Cervical Intraepithelial Neoplasias 1, 2 and 3, Squamous Cell Carcinomas). All patients also had a cervico-vaginal sample for HPV testing, collected immediately before the colposcopy-guided biopsy. The HR-HPV DNA detection was performed by the HR-HPV Hybrid Capture 2 test. HPV genotyping was performed using the Linear Array HPV Genotyping Test. Results Our results evidenced a constant and significant increase of the rate of claspin positivity from the normal tissues to carcinomas (pχ2trend < 0.0001). In fact, the normal tissues displayed either no or faint claspin immunoreactivity, whereas a moderate/high positivity was observed in 16% of the CIN1, 76% of the CIN2, 87.5% of the CIN3 and 93.3% of the cancers. Moreover, we found a statistically significant correlation between claspin expression and HR-HPV infection (pχ2 < 0.0001), irrespective of the genotype. Finally, we demonstrated the feasibility of claspin immunostaining in cervical cytology. Conclusions Our findings indicate that in vivo claspin expression is significantly related to HR-HPV infection and lesion grade both in histological and cytological samples. Therefore, the analysis of claspin expression could be clinically relevant in the diagnosis of HPV-related cervical lesions, in particular when applied to cervico

  10. Effects of grayscale window/level parameters on breast lesion detectability

    NASA Astrophysics Data System (ADS)

    Johnson, Jeffrey P.; Nafziger, John S.; Krupinski, Elizabeth A.; Lubin, Jeffrey; Roehrig, Hans

    2003-05-01

    The detectability of low-contrast lesions in medical images can be affected significantly by the choice of grayscale window width and level (W/L) for electronic display. Our objective was to measure the effects of various W/L conditions on lesion detectability in simulated and real mammographic images, and then correlate observer performance with predictions of detection thresholds derived from a visual discrimination model (VDM). In the first experiment, detection thresholds were measured in 2AFC trials for five W/L conditions applied to simulated mammographic backgrounds and lesions (i.e., Gaussian "masses" and blurred-disk "microcalcification clusters") using nonmedical observers. In the second experiment, the detectability of real microcalcification clusters in digitized mammograms was evaluated for three W/L conditions in an ROC observer study with mammographers. For the simulated images, there was generally good agreement between model and experimental thresholds and their variations across W/L conditions. Both experimental and model results showed significant reductions in thresholds when W/L processing was applied locally near the lesion. ROC results with digitized mammograms read by radiologists, however, failed to show enhanced detection of microcalcifications using a localized W/L frame, probably due to the nonuniform appearance of parenchymal tissue across the image.

  11. Enhancing the detection of hidden occlusal caries lesions with OCT using high index liquids

    NASA Astrophysics Data System (ADS)

    Kang, Hobin; Darling, Cynthia L.; Fried, Daniel

    2014-02-01

    In a previous study, we investigated the influence of several high refractive index fluids on the performance of polarization sensitive optical coherence tomography (PS-OCT). That study showed that these liquids can increase the effective imaging depth and lesion contrast. Other in vitro and in vivo studies have shown that OCT can be used to show whether occlusal lesions have penetrated to the dentinal-enamel junction (DEJ) and spread laterally under the enamel. The purpose of this study was to determine if high index fluids can enhance the ability of OCT to detect hidden occlusal lesions and show if these lesions have penetrated through the enamel into the underlying dentin. Ten extracted teeth with occlusal lesions were imaged using OCT after the application of water, glycerol, BABB (33% Benzyl Alcohol + 67% Benzyl Benzoate) and a Cargille Liquid (Cedar Grove, NJ) (hydrogenated terphenyl 1- bromo-naphthalene) with a refractive index of 1.61. The intensity of the reflectance from the underlying lesion area for each sample was compared with the reflectance of the sound tooth surface for each fluid. The use of high index fluids significantly (P< 0.0001) increased the reflectivity of subsurface occlusal lesions under the surrounding sound enamel.

  12. Automated detection of remineralization in simulated enamel lesions with PS-OCT

    NASA Astrophysics Data System (ADS)

    Lee, Robert C.; Darling, Cynthia L.; Fried, Daniel

    2014-02-01

    Previous in vitro and in vivo studies have demonstrated that polarization-sensitive optical coherence tomography (PS-OCT) can be used to nondestructively image the subsurface structure and measure the thickness of the highly mineralized transparent surface zone of caries lesions. There are structural differences between active lesions and arrested lesions, and the surface layer thickness may correlate with activity of the lesion. The purpose of this study was to develop a method that can be used to automatically detect and measure the thickness of the transparent surface layer in PS-OCT images. Automated methods of analysis were used to measure the thickness of the transparent layer and the depth of the bovine enamel lesions produced using simulated caries models that emulate demineralization in the mouth. The transparent layer thickness measured with PS-OCT correlated well with polarization light microscopy (PLM) measurements of all regions (r2=0.9213). This study demonstrates that PS-OCT can automatically detect and measure thickness of the transparent layer formed due to remineralization in simulated caries lesions.

  13. Detection of HPV-induced cervical (pre) neoplastic lesions: a tissue microarray (TMA) study.

    PubMed

    Arafa, Mohammad; Boniver, Jacques; Delvenne, Philippe

    2008-10-01

    The aim of this study was to evaluate the usefulness of a panel of biomarkers in the characterization of human papillomavirus (HPV)-induced cervical lesions. Management of these lesions depends on their histologic confirmation. Misinterpretation especially for benign mimics results in a significant diagnostic disagreement. For these reasons, a continuous effort is still needed to discover surrogate markers, which could support the final diagnosis. Archival biopsies of normal ectocervical and endocervical tissues, squamous metaplasia, cervical intraepithelial neoplasia (CIN), squamous cell carcinoma, adenocarcinoma in situ, and adenocarcinoma were retrieved to perform a tissue microarray (TMA). A panel of markers was tested on the TMA obtained slides by in situ hybridization (HPV DNA) and immunohistochemistry (p16, involucrin, Ki-67, and HPV L1 proteins). The sensitivity to detect high-risk HPV DNA increased with lesion's severity. In situ hybridization signals suggesting integrated viral physical status predominated in CIN II/III, squamous cell carcinoma, and glandular (pre) neoplastic lesions. The p16 and Ki-67 protein expression increased from CIN I to CIN III and to infiltrative lesions. Involucrin positivity was better appreciated in well-differentiated diagnostic entities (ectocervix, mature metaplasia, and CIN I). HPV L1 antibody detected the viral capsid protein in a low proportion of CIN I and II. In conclusion, using a panel of cervical biomarkers improves the final reporting of various HPV-induced epithelial lesions. Carefully constructed TMA with single spots of 1-mm diameter are powerful tools, which have a high reliability in representing full tissue sections.

  14. Ameloblastic fibroma and related lesions: current pathologic concept.

    PubMed

    Takeda, Y

    1999-11-01

    Ameloblastic fibroma (AF) is a true mixed tumor, in which the epithelial and the ectomesenchymal elements are neoplastic. There are two rare variants of AF; granular cell AF and peripheral AF. Ameloblastic fibrosarcoma is a rare tumor, and is regarded as the malignant counterpart of the benign AF. Recent immunohistochemical study using MIB-1 shows labelling indices in the mesenchymal component of the recurrent AF and ameloblastic fibrosarcoma are quite high, in contrast with the conventional AF. Ameloblastic fibrodentinoma is a histologic variant of AF in which dentin or dentinoid tissue has formed, but there is no eveidence that ameloblastic fibrodentinoma exhibit a different biologic behavior than ordinary AF. Ameloblastic fibro-odontoma is a lesion similar to AF, but also showing inductive changes that lead to the formation of both dentin and enamel. Some lesions diagnosed as ameloblastic fibro-odontoma are probably developing odontoma, but the others should not be considered as hamartomatous in nature, since there are rare cases of ameloblastic fibro-odontoma showing true neoplastic behavior, and since the existence of malignant variant is evident. In revised WHO's classification of odontogenic tumors, the terms "ameloblastic fibrodentinoma" and "dentinoma" are used synonymously, however, there are histologic difference between several cases reported previously as "dentinoma" and ameloblastic fibrodentinoma.

  15. Impact of breast structure on lesion detection in breast tomosynthesis, a simulation study

    PubMed Central

    Kiarashi, Nooshin; Nolte, Loren W.; Lo, Joseph Y.; Segars, W. Paul; Ghate, Sujata V.; Solomon, Justin B.; Samei, Ehsan

    2016-01-01

    Abstract. This study aims to characterize the effect of background tissue density and heterogeneity on the detection of irregular masses in breast tomosynthesis, while demonstrating the capability of the sophisticated tools that can be used in the design, implementation, and performance analysis of virtual clinical trials (VCTs). Twenty breast phantoms from the extended cardiac-torso (XCAT) family, generated based on dedicated breast computed tomography of human subjects, were used to extract a total of 2173 volumes of interest (VOIs) from simulated tomosynthesis images. Five different lesions, modeled after human subject tomosynthesis images, were embedded in the breasts and combined with the lesion absent condition yielded a total of 6×2173 VOIs. Effects of background tissue density and heterogeneity on the detection of the lesions were studied by implementing a composite hypothesis signal detection paradigm with location known exactly, lesion known exactly or statistically, and background known statistically. Using the area under the receiver operating characteristic curve, detection performance deteriorated as density was increased, yielding findings consistent with clinical studies. A human observer study was performed on a subset of the simulated tomosynthesis images, confirming the detection performance trends with respect to density and serving as a validation of the implemented detector. Performance of the implemented detector varied substantially across the 20 breasts. Furthermore, background tissue density and heterogeneity affected the log-likelihood ratio test statistic differently under lesion absent and lesion present conditions. Therefore, considering background tissue variability in tissue models can change the outcomes of a VCT and is hence of crucial importance. The XCAT breast phantoms have the potential to address this concern by offering realistic modeling of background tissue variability based on a wide range of human subjects, comprising

  16. Impact of breast structure on lesion detection in breast tomosynthesis, a simulation study.

    PubMed

    Kiarashi, Nooshin; Nolte, Loren W; Lo, Joseph Y; Segars, W Paul; Ghate, Sujata V; Solomon, Justin B; Samei, Ehsan

    2016-07-01

    This study aims to characterize the effect of background tissue density and heterogeneity on the detection of irregular masses in breast tomosynthesis, while demonstrating the capability of the sophisticated tools that can be used in the design, implementation, and performance analysis of virtual clinical trials (VCTs). Twenty breast phantoms from the extended cardiac-torso (XCAT) family, generated based on dedicated breast computed tomography of human subjects, were used to extract a total of 2173 volumes of interest (VOIs) from simulated tomosynthesis images. Five different lesions, modeled after human subject tomosynthesis images, were embedded in the breasts and combined with the lesion absent condition yielded a total of [Formula: see text] VOIs. Effects of background tissue density and heterogeneity on the detection of the lesions were studied by implementing a composite hypothesis signal detection paradigm with location known exactly, lesion known exactly or statistically, and background known statistically. Using the area under the receiver operating characteristic curve, detection performance deteriorated as density was increased, yielding findings consistent with clinical studies. A human observer study was performed on a subset of the simulated tomosynthesis images, confirming the detection performance trends with respect to density and serving as a validation of the implemented detector. Performance of the implemented detector varied substantially across the 20 breasts. Furthermore, background tissue density and heterogeneity affected the log-likelihood ratio test statistic differently under lesion absent and lesion present conditions. Therefore, considering background tissue variability in tissue models can change the outcomes of a VCT and is hence of crucial importance. The XCAT breast phantoms have the potential to address this concern by offering realistic modeling of background tissue variability based on a wide range of human subjects, comprising

  17. Automated detection of spiculated lesions and architectural distortions in digitized mammograms

    NASA Astrophysics Data System (ADS)

    Zhang, Ming; Giger, Maryellen L.

    1995-05-01

    Mammographic stellate lesions and architectural distortions are usually associated with malignancy, which makes them important signs in the screening for breast cancer. This paper proposes a novel method for the automatic detection of these lesions with the use of a Hough spectrum based geometric texture analysis. The Hough spectrum technique is developed from the traditional Hough transform, which is effective in the description of geometric structures. The Hough spectrum inherits such an ability and extends it into texture analysis for the description of those texture features geometric in nature, such as the spicula of a stellate lesion. When applied in mammographic image processing, an ROI is first transformed into its Hough spectrum, and then thresholding is conducted with its threshold level based on the statistical properties of the spectrum. Those ROIs with strong signals of spiculation are then identified as regions of potential lesions. Our preliminary studies, using only the Hough spectrum based technique without further feature analyses to reduce false positive detection, have yielded sensitivities of 81% for spiculated masses and 67% for architectural distortions at false positive rates of 0.97 and 2.2 per image, respectively. This manifests clearly the potential of the developed technique in the detection of such types of mammographic lesions.

  18. Validity of MicroCT for in vitro detection of proximal carious lesions in primary molars.

    PubMed

    Soviero, V M; Leal, S C; Silva, R C; Azevedo, R B

    2012-01-01

    This study aimed to validate the MicroCT for detection of proximal carious lesions in primary molars, using histology as the gold standard. Forty-eight proximal surfaces of primary molars were examined. Two calibrated examiners conducted the examinations independently. Proximal surfaces were visually scored, using ICDAS. Bitewing radiographs, Micro-CT and histological analyses used caries scores: 0=sound; 1=outer enamel; 2=inner enamel; 3=not spread dentine; 4=outer dentine; 5=inner dentine. Axial and sagital images were used for Micro-CT analysis, whilst for histology, tooth sections (400μm) were analyzed stereomicroscopically (×15). Inter-examiner agreement ranged from 0.87 to 0.93 kappa coefficient (k). Histological analysis revealed a frequency of sound tooth surfaces (18.8%) enamel carious lesions (E1) (48%) and dentine carious lesions (D1) (33.3%). MicroCT showed high correlation with histology (r(s)0.88). At both diagnostic thresholds (E1 and D1), sensitivity and accuracy were higher for MicroCT. Inter-device agreement between MicroCT and histology was k=0.81. No difference was found between MicroCT and histology as gold standards for detecting carious lesions using ICDAS. MicroCT can be used as a gold standard for detecting carious lesions in proximal surfaces in primary molars. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Optimised nuclear medicine method for tumour marking and sentinel node detection in occult primary breast lesions.

    PubMed

    De Cicco, C; Trifirò, G; Intra, M; Marotta, G; Ciprian, A; Frasson, A; Prisco, G; Luini, A; Viale, G; Paganelli, G

    2004-03-01

    The aim of this study was to evaluate the feasibility of sentinel node (SN) biopsy in occult breast lesions with different radiopharmaceuticals and to establish the optimal lymphoscintigraphic method to detect both occult lesions and SNs (SNOLL: sentinel node and occult lesion localisation). Two hundred and twenty-seven consecutive patients suspected to have clinically occult breast carcinoma were enrolled in the study. In addition to the radioguided occult lesion localisation (ROLL) procedure, using macroaggregates of technetium-99m labelled human serum albumin (MAA) injected directly into the lesion, lymphoscintigraphy was performed with nanocolloids (NC) injected in a peritumoral (group I) or a subdermal site (group II). In group III, a sole injection of NC was done into the lesion in order to perform both ROLL and SNOLL. Overall, axillary SNs were identified in 205 of the 227 patients (90.3%). In 12/62 (19.4%) patients of group I and 9/79 (11.4%) patients of group III, radioactive nodes were not visualised, whereas SNs were successfully localised in 85 of 86 patients of group II ( P<0.001). Pathological findings revealed breast carcinoma in 148/227 patients (65.2%) and benign lesions in 79 (34.8%). A total of 131 axillary SNs were removed in 118 patients with breast carcinoma; intraoperative examination of the SNs revealed metastatic involvement in 16 out of 96 cases of invasive carcinoma (16.7%). It is concluded that the combination of the ROLL procedure with direct injection of MAA into the lesion and lymphoscintigraphy performed with subdermal injection of radiocolloids represents the method of choice for accurate localisation of both non-palpable lesions and SNs.

  20. Brain MRI segmentation and lesion detection using generalized Gaussian and Rician modeling

    NASA Astrophysics Data System (ADS)

    Wu, Xuqiang; Bricq, Stéphanie; Collet, Christophe

    2011-03-01

    In this paper we propose a mixed noise modeling so as to segment the brain and to detect lesion. Indeed, accurate segmentation of multimodal (T1, T2 and Flair) brain MR images is of great interest for many brain disorders but requires to efficiently manage multivariate correlated noise between available modalities. We addressed this problem in1 by proposing an entirely unsupervised segmentation scheme, taking into account multivariate Gaussian noise, imaging artifacts,intrinsic tissue variation and partial volume effects in a Bayesian framework. Nevertheless, tissue classification remains a challenging task especially when one addresses the lesion detection during segmentation process2 as we did. In order to improve brain segmentation into White and Gray Matter (resp. WM and GM) and cerebro-spinal fluid (CSF), we propose to fit a Rician (RC) density distribution for CSF whereas Generalized Gaussian (GG) models are used to fit the likelihood between model and data corresponding to WM and GM. In this way, we present in this paper promising results showing that in a multimodal segmentation-detection scheme, this model fits better with the data and increases lesion detection rate. One of the main challenges consists in being able to take into account various pdf (Gaussian and non- Gaussian) for correlated noise between modalities and to show that lesion-detection is then clearly improved, probably because non-Gaussian noise better fits to the physic of MRI image acquisition.

  1. Clinically and mammographically occult breast lesions: detection and classification with high-resolution sonography.

    PubMed

    Buchberger, W; Niehoff, A; Obrist, P; DeKoekkoek-Doll, P; Dünser, M

    2000-08-01

    With recent significant advances in ultrasound technology, the potential of high-resolution sonography to improve the sensitivity of cancer diagnosis in women with dense breasts has become a matter of interest for breast imagers. To determine how often physician-performed high-resolution sonography can detect nonpalpable breast cancers that are not revealed by mammography, 8,970 women with breast density grades 2 through 4 underwent high-resolution sonography as an adjunct to mammography. All sonographically detected, clinically and mammographically occult breast lesions that were not simple cysts were prospectively classified into benign, indeterminate, or malignant categories. Diagnoses were confirmed by ultrasound-guided fine-needle aspiration, core-needle biopsy, or surgical biopsy. In 8,103 women with normal findings at mammography and physical examination, 32 cancers and 330 benign lesions were detected in 273 patients with sonography only. Eight additional cancers were found in 867 patients with a malignant (n = 5) or a benign (n = 3) palpable or mammographically detected index lesion. The overall prevalence of cancers detected with screening sonography was 0.41%, and the proportion of sonographically detected cancers to the total number of nonpalpable cancers was 22%. The mean size of invasive cancers detected only by sonography was 9.1 mm, and was not statistically different from the mean size of invasive cancers detected by mammography. The sensitivity of prospective sonographic classification for malignancy was 100%, and the specificity was 31%. In conclusion, the use of high-resolution sonography as an adjunct to mammography in women with dense breasts may lead to detection of a significant number of otherwise occult cancers that are no different in size from nonpalpable mammographically detected cancers. Prospective classification of these lesions based on sonographic characteristics resulted in an acceptable benign-to-malignant biopsy rate of 6.3:1.

  2. Apraxia related with subcortical lesions due to cerebrovascular disease.

    PubMed

    Tabaki, N E; Vikelis, M; Besmertis, L; Vemmos, K; Stathis, P; Mitsikostas, D D

    2010-07-01

    To examine whether ideomotor apraxia exists in patients with subcortical ischemic lesions. A matched-control, prospective and multi-centered research design was used. Ideomotor apraxia, anxiety and depression were assessed by the Movement Imitation Test and the Hamilton scales, respectively. Forty two consecutive patients with subcortical ischemic stroke and an equal number of healthy participants, matched in age and sex were included. Paired-sample t-tests showed that patients had significantly more apractic elements in their movements (t = 5.03, P < 0.01), higher anxiety (t = -2.55, P = 0.0014) and depression levels (t = -2.61, P = 0.012) than their healthy matched participants. Participants with higher anxiety and depression scores performed worse on the Movement Imitation Test. Ischemic damage of subcortical modular systems may affect praxis.

  3. Detection of early carious lesions using contrast enhancement with coherent light scattering (speckle imaging)

    NASA Astrophysics Data System (ADS)

    Deana, A. M.; Jesus, S. H. C.; Koshoji, N. H.; Bussadori, S. K.; Oliveira, M. T.

    2013-07-01

    Currently, dental caries still represent one of the chronic diseases with the highest prevalence and present in most countries. The interaction between light and teeth (absorption, scattering and fluorescence) is intrinsically connected to the constitution of the dental tissue. Decay induced mineral loss introduces a shift in the optical properties of the affected tissue; therefore, study of these properties may produce novel techniques aimed at the early diagnosis of carious lesions. Based on the optical properties of the enamel, we demonstrate the application of first-order spatial statistics in laser speckle imaging, allowing the detection of carious lesions in their early stages. A highlight of this noninvasive, non-destructive, real time and cost effective approach is that it allows a dentist to detect a lesion even in the absence of biofilm or moisture.

  4. Lesion Characteristics Related to Treatment Improvement in Object and Action Naming for Patients with Chronic Aphasia

    ERIC Educational Resources Information Center

    Parkinson, R. Bruce; Raymer, Anastasia; Chang, Yu-Ling; FitzGerald, David B.; Crosson, Bruce

    2009-01-01

    Few studies have examined the relationship between degree of lesion in various locations and improvement during treatment in stroke patients with chronic aphasia. The main purpose of this study was to determine whether the degree of lesion in specific brain regions was related to magnitude of improvement over the course of object and action naming…

  5. Lesion Characteristics Related to Treatment Improvement in Object and Action Naming for Patients with Chronic Aphasia

    ERIC Educational Resources Information Center

    Parkinson, R. Bruce; Raymer, Anastasia; Chang, Yu-Ling; FitzGerald, David B.; Crosson, Bruce

    2009-01-01

    Few studies have examined the relationship between degree of lesion in various locations and improvement during treatment in stroke patients with chronic aphasia. The main purpose of this study was to determine whether the degree of lesion in specific brain regions was related to magnitude of improvement over the course of object and action naming…

  6. In vitro performance of different methods in detecting occlusal caries lesions.

    PubMed

    Gomez, J; Zakian, C; Salsone, S; Pinto, S C S; Taylor, A; Pretty, I A; Ellwood, R

    2013-02-01

    Early caries detection is essential for the implementation of preventive, therapeutic and intervention strategies within general dental practice. The aim of this study was to compare the in vitro performance of the International Caries Detection and Assessment System (ICDAS), digital photographs scored with ICDAS (ICDAS photographs), fibre-optic transillumination (FOTI), optical coherence tomography (OCT), SoproLife(®) camera and two implementations of quantitative light-induced fluorescence a commercial (QLF-Inspektor Research systems) and a custom (QLF-Custom) system, to detect early and intermediate occlusal lesions. One hundred and twelve permanent extracted teeth were selected and assessed with each detection method. Histological validation was used as a gold standard. The detection methods were compared by means of sensitivity, specificity, areas under receiver operating characteristic (AUROC) curves for enamel and dentine levels and with the Spearman's rank correlation coefficient against histology. For any enamel or dentine caries detection, the AUROC curves ranged from 0.86 (OCT) to 0.98 (ICDAS and ICDAS photographs, SoproLife(®) camera) and at the dentine level from 0.83 (OCT) to 0.96 for FOTI. The correlations with histology ranged between 0.65 (OCT) and 0.88 (ICDAS and FOTI). Under in vitro conditions, the assessed detection methods showed excellent intra-examiner reproducibility. All the methods were strongly correlated with histology (p<0.01) except OCT which showed a moderate correlation (0.65). Even though all methods present similar performance in detecting occlusal caries lesions, visual inspection seems to be sufficient to be used in clinical practice for detection and assessment of lesion depth. Other methods may be useful in monitoring caries lesion behaviour. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Lesion detection in magnetic resonance brain images by hyperspectral imaging algorithms

    NASA Astrophysics Data System (ADS)

    Xue, Bai; Wang, Lin; Li, Hsiao-Chi; Chen, Hsian Min; Chang, Chein-I.

    2016-05-01

    Magnetic Resonance (MR) images can be considered as multispectral images so that MR imaging can be processed by multispectral imaging techniques such as maximum likelihood classification. Unfortunately, most multispectral imaging techniques are not particularly designed for target detection. On the other hand, hyperspectral imaging is primarily developed to address subpixel detection, mixed pixel classification for which multispectral imaging is generally not effective. This paper takes advantages of hyperspectral imaging techniques to develop target detection algorithms to find lesions in MR brain images. Since MR images are collected by only three image sequences, T1, T2 and PD, if a hyperspectral imaging technique is used to process MR images it suffers from the issue of insufficient dimensionality. To address this issue, two approaches to nonlinear dimensionality expansion are proposed, nonlinear correlation expansion and nonlinear band ratio expansion. Once dimensionality is expanded hyperspectral imaging algorithms are readily applied. The hyperspectral detection algorithm to be investigated for lesion detection in MR brain is the well-known subpixel target detection algorithm, called Constrained Energy Minimization (CEM). In order to demonstrate the effectiveness of proposed CEM in lesion detection, synthetic images provided by BrainWeb are used for experiments.

  8. Computer-aided detection of early neoplastic lesions in Barrett's esophagus.

    PubMed

    van der Sommen, Fons; Zinger, Svitlana; Curvers, Wouter L; Bisschops, Raf; Pech, Oliver; Weusten, Bas L A M; Bergman, Jacques J G H M; de With, Peter H N; Schoon, Erik J

    2016-07-01

    Early neoplasia in Barrett's esophagus is difficult to detect and often overlooked during Barrett's surveillance. An automatic detection system could be beneficial, by assisting endoscopists with detection of early neoplastic lesions. The aim of this study was to assess the feasibility of a computer system to detect early neoplasia in Barrett's esophagus. Based on 100 images from 44 patients with Barrett's esophagus, a computer algorithm, which employed specific texture, color filters, and machine learning, was developed for the detection of early neoplastic lesions in Barrett's esophagus. The evaluation by one endoscopist, who extensively imaged and endoscopically removed all early neoplastic lesions and was not blinded to the histological outcome, was considered the gold standard. For external validation, four international experts in Barrett's neoplasia, who were blinded to the pathology results, reviewed all images. The system identified early neoplastic lesions on a per-image analysis with a sensitivity and specificity of 0.83. At the patient level, the system achieved a sensitivity and specificity of 0.86 and 0.87, respectively. A trade-off between the two performance metrics could be made by varying the percentage of training samples that showed neoplastic tissue. The automated computer algorithm developed in this study was able to identify early neoplastic lesions with reasonable accuracy, suggesting that automated detection of early neoplasia in Barrett's esophagus is feasible. Further research is required to improve the accuracy of the system and prepare it for real-time operation, before it can be applied in clinical practice. © Georg Thieme Verlag KG Stuttgart · New York.

  9. Targeting Premalignant Lesions: Implications for Early Breast Cancer Detection and Intervention

    DTIC Science & Technology

    2016-04-01

    1 AWARD NUMBER: W81XWH-14-1-0032 TITLE: Targeting Premalignant Lesions: Implications for Early Breast Cancer Detection and Intervention...ABSTRACT Breast cancer progression constitutes a multistep process through a series of intermediate hyperplastic and neoplastic stages to invasive...Considerable numbers of CAFs are frequently observed within the tumor- associated stroma of various human cancers , including those of the breast

  10. Remote optical configuration of pigmented lesion detection and diagnosis of bone fractures

    NASA Astrophysics Data System (ADS)

    Ozana, Nisan; Bishitz, Yael; Beiderman, Yevgeny; Garcia, Javier; Zalevsky, Zeev; Schwarz, Ariel

    2016-02-01

    In this paper we present a novel approach of realizing a safe, simple, and inexpensive sensor applicable to bone fractures and pigmented lesions detection. The approach is based on temporal tracking of back-reflected secondary speckle pattern generated while illuminating the affected area with a laser and applying periodic pressure to the surface via a controlled vibration. The use of such a concept was already demonstrated for non-contact monitoring of various bio-medical parameters such as heart rate, blood pulse pressure, concentration of alcohol and glucose in the blood stream and intraocular pressure. The presented technique is a safe and effective method of detecting bone fractures in populations at risk. When applied to pigmented lesions, the technique is superior to visual examination in avoiding many false positives and resultant unnecessary biopsies. Applying a series of different vibration frequencies at the examined tissue and analyzing the 2-D speckle pattern trajectory in response to the applied periodic pressure creates a unique signature for each and different pigmented lesion. Analyzing these signatures is the first step toward detection of malignant melanoma. In this paper we present preliminary experiments that show the validity of the developed sensor for both applications: the detection of damaged bones as well as the classification of pigmented lesions.

  11. Low tube voltage CT for improved detection of pancreatic cancer: detection threshold for small, simulated lesions

    PubMed Central

    2012-01-01

    Background Pancreatic ductal adenocarcinoma is associated with dismal prognosis. The detection of small pancreatic tumors which are still resectable is still a challenging problem. The aim of this study was to investigate the effect of decreasing the tube voltage from 120 to 80 kV on the detection of pancreatic tumors. Methods Three scanning protocols was used; one using the standard tube voltage (120 kV) and current (160 mA) and two using 80 kV but with different tube currents (500 and 675 mA) to achieve equivalent dose (15 mGy) and noise (15 HU) as that of the standard protocol. Tumors were simulated into collected CT phantom images. The attenuation in normal parenchyma at 120 kV was set at 130 HU, as measured previously in clinical examinations, and the tumor attenuation was assumed to differ 20 HU and was set at 110HU. By scanning and measuring of iodine solution with different concentrations the corresponding tumor and parenchyma attenuation at 80 kV was found to be 185 and 219 HU, respectively. To objectively evaluate the differences between the three protocols, a multi-reader multi-case receiver operating characteristic study was conducted, using three readers and 100 cases, each containing 0–3 lesions. Results The highest reader averaged figure-of-merit (FOM) was achieved for 80 kV and 675 mA (FOM = 0,850), and the lowest for 120 kV (FOM = 0,709). There was a significant difference between the three protocols (p < 0,0001), when making an analysis of variance (ANOVA). Post-hoc analysis (students t-test) shows that there was a significant difference between 120 and 80 kV, but not between the two levels of tube currents at 80 kV. Conclusion We conclude that when decreasing the tube voltage there is a significant improvement in tumor conspicuity. PMID:22828284

  12. Automatic ultrasonic breast lesions detection using support vector machine based algorithm

    NASA Astrophysics Data System (ADS)

    Yeh, Chih-Kuang; Miao, Shan-Jung; Fan, Wei-Che; Chen, Yung-Sheng

    2007-03-01

    It is difficult to automatically detect tumors and extract lesion boundaries in ultrasound images due to the variance in shape, the interference from speckle noise, and the low contrast between objects and background. The enhancement of ultrasonic image becomes a significant task before performing lesion classification, which was usually done with manual delineation of the tumor boundaries in the previous works. In this study, a linear support vector machine (SVM) based algorithm is proposed for ultrasound breast image training and classification. Then a disk expansion algorithm is applied for automatically detecting lesions boundary. A set of sub-images including smooth and irregular boundaries in tumor objects and those in speckle-noised background are trained by the SVM algorithm to produce an optimal classification function. Based on this classification model, each pixel within an ultrasound image is classified into either object or background oriented pixel. This enhanced binary image can highlight the object and suppress the speckle noise; and it can be regarded as degraded paint character (DPC) image containing closure noise, which is well known in perceptual organization of psychology. An effective scheme of removing closure noise using iterative disk expansion method has been successfully demonstrated in our previous works. The boundary detection of ultrasonic breast lesions can be further equivalent to the removal of speckle noise. By applying the disk expansion method to the binary image, we can obtain a significant radius-based image where the radius for each pixel represents the corresponding disk covering the specific object information. Finally, a signal transmission process is used for searching the complete breast lesion region and thus the desired lesion boundary can be effectively and automatically determined. Our algorithm can be performed iteratively until all desired objects are detected. Simulations and clinical images were introduced to

  13. Artifactual mutations resulting from DNA lesions limit detection levels in ultrasensitive sequencing applications

    PubMed Central

    Arbeithuber, Barbara; Makova, Kateryna D.; Tiemann-Boege, Irene

    2016-01-01

    The need in cancer research or evolutionary biology to detect rare mutations or variants present at very low frequencies (<10−5) poses an increasing demand on lowering the detection limits of available methods. Here we demonstrated that amplifiable DNA lesions introduce important error sources in ultrasensitive technologies such as single molecule PCR (smPCR) applications (e.g. droplet-digital PCR), or next-generation sequencing (NGS) based methods. Using templates with known amplifiable lesions (8-oxoguanine, deaminated 5-methylcytosine, uracil, and DNA heteroduplexes), we assessed with smPCR and duplex sequencing that templates with these lesions were amplified very efficiently by proofreading polymerases (except uracil), leading to G->T, and to a lesser extent, to unreported G->C substitutions at 8-oxoguanine lesions, and C->T transitions in amplified uracil containing templates. Long heat incubations common in many DNA extraction protocols significantly increased the number of G->T substitutions. Moreover, in ∼50-80% smPCR reactions we observed the random amplification preference of only one of both DNA strands explaining the known ‘PCR jackpot effect’, with the result that a lesion became indistinguishable from a true mutation or variant. Finally, we showed that artifactual mutations derived from uracil and 8-oxoguanine could be significantly reduced by DNA repair enzymes. PMID:27477585

  14. Artifactual mutations resulting from DNA lesions limit detection levels in ultrasensitive sequencing applications.

    PubMed

    Arbeithuber, Barbara; Makova, Kateryna D; Tiemann-Boege, Irene

    2016-12-01

    The need in cancer research or evolutionary biology to detect rare mutations or variants present at very low frequencies (<10(-5)) poses an increasing demand on lowering the detection limits of available methods. Here we demonstrated that amplifiable DNA lesions introduce important error sources in ultrasensitive technologies such as single molecule PCR (smPCR) applications (e.g. droplet-digital PCR), or next-generation sequencing (NGS) based methods. Using templates with known amplifiable lesions (8-oxoguanine, deaminated 5-methylcytosine, uracil, and DNA heteroduplexes), we assessed with smPCR and duplex sequencing that templates with these lesions were amplified very efficiently by proofreading polymerases (except uracil), leading to G->T, and to a lesser extent, to unreported G->C substitutions at 8-oxoguanine lesions, and C->T transitions in amplified uracil containing templates. Long heat incubations common in many DNA extraction protocols significantly increased the number of G->T substitutions. Moreover, in ∼50-80% smPCR reactions we observed the random amplification preference of only one of both DNA strands explaining the known 'PCR jackpot effect', with the result that a lesion became indistinguishable from a true mutation or variant. Finally, we showed that artifactual mutations derived from uracil and 8-oxoguanine could be significantly reduced by DNA repair enzymes. © The Author 2016. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

  15. A fully automatic lesion detection method for DCE-MRI fat-suppressed breast images

    NASA Astrophysics Data System (ADS)

    Vignati, Anna; Giannini, Valentina; Bert, Alberto; Deluca, Massimo; Morra, Lia; Persano, Diego; Martincich, Laura; Regge, Daniele

    2009-02-01

    Dynamic Contrast Enhanced MRI (DCE-MRI) has today a well-established role, complementary to routine imaging techniques for breast cancer diagnosis such as mammography. Despite its undoubted clinical advantages, DCE-MRI data analysis is time-consuming and Computer Aided Diagnosis (CAD) systems are required to help radiologists. Segmentation is one of the key step of every CAD image processing pipeline, but most techniques available require human interaction. We here present the preliminary results of a fully automatic lesion detection method, capable of dealing with fat suppression image acquisition sequences, which represents a challenge for image processing algorithms due to the low SNR. The method is based on four fundamental steps: registration to correct for motion artifacts; anatomical segmentation to discard anatomical structures located outside clinically interesting lesions; lesion detection to select enhanced areas and false positive reduction based on morphological and kinetic criteria. The testing set was composed by 13 cases and included 27 lesions (10 benign and 17 malignant) of diameter > 5 mm. The system achieves a per-lesion sensitivity of 93%, while yielding an acceptable number of false positives (26 on average). The results of our segmentation algorithm were verified by visual inspection, and qualitative comparison with a manual segmentation yielded encouraging results.

  16. Relative fluoride response of caries lesions created in fluorotic and sound teeth studied under remineralizing conditions.

    PubMed

    Alhawij, Hala; Lippert, Frank; Martinez-Mier, Esperanza Angeles

    2015-01-01

    The present in vitro pH cycling study investigated potential differences between caries lesions created in fluorosed and sound enamel with regards to their responsiveness to fluoride under remineralizing conditions. 360 human first molars (sound and fluorosed) were divided into four groups based on their Thylstrup-Fejerskov score (TF0-3). Each group was further divided into two treatment groups (n=45): deionized water or 383 ppm fluoride. Artificial enamel caries lesions were created and pH cycled for 20 d using an established net remineralization model. Quantitative light-induced fluorescence was used throughout the study to investigate lesion severity and changes thereof. Data were analyzed using two-way ANOVA. There were no differences in lesion severity between all groups after lesion creation (plesion=0.1934). The TF score vs. treatment interaction was significant at all other time points (p10 d=0.0280; p20 d≤0.0001; psecdemin=0.0411). Relative differences in responsiveness to fluoride vs. deionized water increased with increasing TF scores. In comparison to lesions created in sound enamel, lesions created in enamel with moderate fluorosis (TF 2/3) were more prone to remineralization in the presence than in the absence of fluoride. Furthermore, lesions created in enamel with moderate fluorosis exhibited more remineralization in the presence of fluoride than lesions created in sound teeth, whereas the opposite was true for deionized water. Bearing in mind the limitations of laboratory research, the extent of enamel fluorosis severity may directly impact subsequent lesion re- and progression as well as the lesion's responsiveness to fluoride. Caries lesions in fluorotic teeth are more vulnerable to progression but respond more strongly to fluoride than those in non-impacted teeth. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Detection of Occlusal Carious Lesion using the SoproLife(®) Camera: A Systematic Review.

    PubMed

    Doméjean, Sophie; Rongier, Julie; Muller-Bolla, Michéle

    2016-09-01

    The aim of this systematic review was to assess the in vivo scientific evidence regarding the ability of a recently developed light fluorescence device, SoproLife(®) (Sopro-Acteon group, La Ciotat, France) in detecting occlusal carious lesions. The PubMed database was searched for in vivo trials that evaluated the validity of the SoproLife(®) camera for the detection of occlusal carious lesions. Among the 11 articles originally identified with the keyword "Soprolife," only three articles were included. The three included surveys used the International Caries Detection and Assessment System (ICDAS)-II criteria as gold standard for the assessment of SoproLife(®) compared or not to other detection devices (DIAGNOdent(®) and Spectra Caries Detection Aid(®)). Two of the included studies reported only on permanent teeth or both primary and permanent teeth. The SoproLife(®) validity values varied markedly among studies with a sensitivity ranging between 0.43 and 0.95 and a specificity between 0.55 and 1. Interobserver reproducibility with the SoproLife(®) was reported in two of the three studies (0.98 and 0.72) and none of the studies reported about intraobserver reproducibility. No clear-cut conclusion can be made based on the three included clinical studies; further in vivo investigations are needed to confirm the validity of the SoproLife(®) camera in terms of detection of occlusal carious lesions.

  18. Experimental comparison of lesion detectability for four fully-3D PET reconstruction schemes.

    PubMed

    Kadrmas, Dan J; Casey, Michael E; Black, Noel F; Hamill, James J; Panin, Vladimir Y; Conti, Maurizio

    2009-04-01

    The objective of this work was to evaluate the lesion detection performance of four fully-3D positron emission tomography (PET) reconstruction schemes using experimentally acquired data. A multi-compartment anthropomorphic phantom was set up to mimic whole-body (18)F-fluorodeoxyglucose (FDG) cancer imaging and scanned 12 times in 3D mode, obtaining count levels typical of noisy clinical scans. Eight of the scans had 26 (68)Ge "shell-less" lesions (6, 8-, 10-, 12-, 16-mm diameter) placed throughout the phantom with various target:background ratios. This provided lesion-present and lesion-absent datasets with known truth appropriate for evaluating lesion detectability by localization receiver operating characteristic (LROC) methods. Four reconstruction schemes were studied: 1) Fourier rebinning (FORE) followed by 2D attenuation-weighted ordered-subsets expectation-maximization, 2) fully-3D AW-OSEM, 3) fully-3D ordinary-Poisson line-of-response (LOR-)OSEM; and 4) fully-3D LOR-OSEM with an accurate point-spread function (PSF) model. Two forms of LROC analysis were performed. First, a channelized nonprewhitened (CNPW) observer was used to optimize processing parameters (number of iterations, post-reconstruction filter) for the human observer study. Human observers then rated each image and selected the most-likely lesion location. The area under the LROC curve ( A(LROC)) and the probability of correct localization were used as figures-of-merit. The results of the human observer study found no statistically significant difference between FORE and AW-OSEM3D ( A(LROC)=0.41 and 0.36, respectively), an increase in lesion detection performance for LOR-OSEM3D ( A(LROC)=0.45, p=0.076), and additional improvement with the use of the PSF model ( A(LROC)=0.55, p=0.024). The numerical CNPW observer provided the same rankings among algorithms, but obtained different values of A(LROC). These results show improved lesion detection performance for the reconstruction algorithms with

  19. Experimental Comparison of Lesion Detectability for Four Fully-3D PET Reconstruction Schemes

    PubMed Central

    Casey, Michael E.; Black, Noel F.; Hamill, James J.; Panin, Vladimir Y.; Conti, Maurizio

    2009-01-01

    The objective of this work was to evaluate the lesion detection performance of four fully-3D positron emission tomography (PET) reconstruction schemes using experimentally acquired data. A multi-compartment anthropomorphic phantom was set up to mimic whole-body 18F-fluorodeoxyglucose (FDG) cancer imaging and scanned 12 times in 3D mode, obtaining count levels typical of noisy clinical scans. Eight of the scans had 26 68Ge “shell-less” lesions (6, 8-, 10-, 12-, 16-mm diameter) placed throughout the phantom with various target:background ratios. This provided lesion-present and lesion-absent datasets with known truth appropriate for evaluating lesion detectability by localization receiver operating characteristic (LROC) methods. Four reconstruction schemes were studied: 1) Fourier rebinning (FORE) followed by 2D attenuation-weighted ordered-subsets expectation-maximization, 2) fully-3D AW-OSEM, 3) fully-3D ordinary-Poisson line-of-response (LOR-)OSEM; and 4) fully-3D LOR-OSEM with an accurate point-spread function (PSF) model. Two forms of LROC analysis were performed. First, a channelized nonprewhitened (CNPW) observer was used to optimize processing parameters (number of iterations, post-reconstruction filter) for the human observer study. Human observers then rated each image and selected the most-likely lesion location. The area under the LROC curve (ALROC) and the probability of correct localization were used as figures-of-merit. The results of the human observer study found no statistically significant difference between FORE and AW-OSEM3D (ALROC = 0.41 and 0.36, respectively), an increase in lesion detection performance for LOR-OSEM3D (ALROC = 0.45, p = 0.076), and additional improvement with the use of the PSF model (ALROC = 0.55, p = 0.024). The numerical CNPW observer provided the same rankings among algorithms, but obtained different values of ALROC. These results show improved lesion detection performance for the reconstruction algorithms with more

  20. The method for detecting small lesions in medical image based on sliding window

    NASA Astrophysics Data System (ADS)

    Han, Guilai; Jiao, Yuan

    2016-10-01

    At present, the research on computer-aided diagnosis includes the sample image segmentation, extracting visual features, generating the classification model by learning, and according to the model generated to classify and judge the inspected images. However, this method has a large scale of calculation and speed is slow. And because medical images are usually low contrast, when the traditional image segmentation method is applied to the medical image, there is a complete failure. As soon as possible to find the region of interest, improve detection speed, this topic attempts to introduce the current popular visual attention model into small lesions detection. However, Itti model is mainly for natural images. But the effect is not ideal when it is used to medical images which usually are gray images. Especially in the early stages of some cancers, the focus of a disease in the whole image is not the most significant region and sometimes is very difficult to be found. But these lesions are prominent in the local areas. This paper proposes a visual attention mechanism based on sliding window, and use sliding window to calculate the significance of a local area. Combined with the characteristics of the lesion, select the features of gray, entropy, corner and edge to generate a saliency map. Then the significant region is segmented and distinguished. This method reduces the difficulty of image segmentation, and improves the detection accuracy of small lesions, and it has great significance to early discovery, early diagnosis and treatment of cancers.

  1. Detection of equine herpesvirus 3 in equine skin lesions by polymerase chain reaction.

    PubMed

    Kleiboeker, Steven B; Chapman, Rodney K

    2004-01-01

    During a recent breeding season, ulcerative, pustular skin lesions were observed on the external genitalia of 2 mares and 1 stallion within a small herd. Based on the location and description of the skin lesions plus the clinical history, equine coital exanthema, caused by equine herpesvirus 3 (EHV3), was the primary differential diagnosis. Scrapings of skin lesions from the perineum of 2 mares were submitted for diagnostic evaluation. Virus isolation was attempted by inoculation of several cell lines of equine origin, but no cytopathic agent was detected. The skin scrapings were processed for DNA extraction, and polymerase chain reaction (PCR) amplification was performed for herpesvirus DNA polymerase and DNA-packaging protein (terminase) genes using nested, degenerate primers targeted to conserved regions of the herpesvirus genome. Products of the expected sizes were generated for both assays, and subsequent nucleotide sequencing of the amplification products established that EHV3 had been detected in DNA extracted from the skin lesions. Detection of EHV3 was confirmed using an EHV3-specific PCR assay targeted to the gC gene. Using the novel EHV3 nucleotide sequence identified in this report, a sensitive and specific PCR assay targeted to the highly conserved DNA polymerase gene was developed.

  2. Herpes simplex virus detection by ELISA: effect of enzyme amplification, nature of lesion sampled and specimen treatment.

    PubMed

    Clayton, A L; Roberts, C; Godley, M; Best, J M; Chantler, S M

    1986-09-01

    The relative sensitivity of two enzyme detection procedures was investigated in a simultaneous "monoclonal" ELISA for herpes simplex virus (HSV). A cyclical enzyme amplified detection system with alkaline phosphatase, rather than horse-radish peroxidase and a conventional chromogenic substrate, gave an increase in absolute sensitivity and a 20 to 30% increase in the detection of HSV in routine isolation-positive genital specimens collected in transport medium. The HSV detection rate, with both procedures, was shown to vary with the site and clinical stage of lesion sampled; it was highest with penile vesicular lesions. Direct extraction of the swab specimen in a small volume of diluent further increased the sensitivity of antigen detection giving positive and negative predictive values of 100 and 96% respectively. The overall sensitivity of HSV detection was equivalent to that obtained by isolation in cell culture. The amplified ELISA offers an alternative, rapid, simple, non-culture technique for routine HSV diagnosis that does not rely upon retention of virus viability.

  3. Automated and interactive lesion detection and segmentation in uterine cervix images.

    PubMed

    Alush, Amir; Greenspan, Hayit; Goldberger, Jacob

    2010-02-01

    This paper presents a procedure for automatic extraction and segmentation of a class-specific object (or region) by learning class-specific boundaries. We describe and evaluate the method with a specific focus on the detection of lesion regions in uterine cervix images. The watershed segmentation map of the input image is modeled using a Markov random field (MRF) in which watershed regions correspond to binary random variables indicating whether the region is part of the lesion tissue or not. The local pairwise factors on the arcs of the watershed map indicate whether the arc is part of the object boundary. The factors are based on supervised learning of a visual word distribution. The final lesion region segmentation is obtained using a loopy belief propagation applied to the watershed arc-level MRF. Experimental results on real data show state-of-the-art segmentation results on this very challenging task that, if necessary, can be interactively enhanced.

  4. How does the concentration of iodine in enhancing lesions relate to image quality in head CT?

    NASA Astrophysics Data System (ADS)

    Fischman, Aaron M.; Dixon, Robert G.; Huda, Walter; Ogden, Kent M.; Lieberman, Kristin A.; Roskopf, Marsha L.

    2004-05-01

    Patients undergoing head CT examinations with iodinated contrast received 100 cc of Iohexol 240 injected intravenously by hand. We developed a software package to align non-contrast and contrast head CT images, and obtain the "difference image" consisting of the iodine enhancement within a given lesion. This "difference image" of the iodine enhancement was added to the non-contrast study at reduced intensities. The signal to noise ratio (SNR) for detecting the added iodine was taken to be directly proportional to the concentration of contrast in the lesion. The visibility of the lesion enhancement in this composite image was compared with the original contrast image using a six-point scale ranging from 5 (no observable difference) to 0 (unacceptable). Two radiologists evaluated head CT images of eleven metastatic lesions. The iodine concentration required to generate an image quality rank of 3, deemed to be satisfactory for diagnosis (S), was determined. We also performed a Receiver Operating Characteristic (ROC) study to identify the iodine concentration corresponding to an area under the ROC curve of 0.95, which corresponds to the detection threshold (D) for each lesion. Reducing the intensity to 50% resulted in an average image qualtiy score S of 3, suggesting that it may be possible to reduce the administered iodine by a half in head CT examinations with no significant loss of diagnostic performance. The average iodine concentration at the detection threshold D was 16%. The average S:D ratio was 3.8 +/- 1.7, and was similar for both readers. The value of S was independent of enhancement characteristics, whereas the detection threshold D correlated inversely with the size and intensity of the iodine enhancement. The resultant S:D ratio correlated with the lesion area (r2 = 0.31), mean lesion intensity (r2 = 0.44), and the product of the mean lesion intensity and the lesion area (r2 = 0.37). Our results indicate that the SNR of enhancing lesions in head CT that

  5. Lesion characteristics related to treatment improvement in object and action naming for patients with chronic aphasia.

    PubMed

    Parkinson, Bruce R; Raymer, Anastasia; Chang, Yu-Ling; Fitzgerald, David B; Crosson, Bruce

    2009-08-01

    Few studies have examined the relationship between degree of lesion in various locations and improvement during treatment in stroke patients with chronic aphasia. The main purpose of this study was to determine whether the degree of lesion in specific brain regions was related to magnitude of improvement over the course of object and action naming treatments. Fifteen left hemisphere stroke patients with aphasia participated in treatments for object and/or action naming. Two raters assessed extent of lesion in 18 left hemisphere cortical and subcortical regions of interest (ROIs) on CT or MRI scans. Correlations were calculated between composite basal ganglia, anterior cortical, and posterior cortical lesion ratings, on the one hand, and both pretreatment scores and treatment change for both object and action naming, on the other hand. Unexpectedly, greater anterior cortical lesion extent was highly correlated with better object and action naming scores prior to treatment and with greater improvement during treatment when partial correlations controlled for total basal ganglia lesion extent (r ranging from .730 to .858). Greater total basal ganglia lesion extent was highly correlated with worse object and action naming scores prior to treatment and with less improvement during treatment when partial correlations controlled for total anterior lesion extent (r ranging from -.623 to -.785). Correlations between degree of posterior cortical lesion and naming indices generally were not significant. No consistent differences were found between the correlations of ROI lesion ratings with object naming versus action naming scores. Large anterior cortical lesions and intactness of the basal ganglia may both contribute to more efficient reorganization of language functions.

  6. Parathyroid incidentalomas detected during thyroid ultrasonography and effect of chronic thyroiditis on false positive parathyroid lesions.

    PubMed

    Ozdemir, Didem; Arpaci, Dilek; Ucler, Rifki; Cuhaci, Neslihan; Ersoy, Reyhan; Cakir, Bekir

    2012-12-01

    We aimed to determine the prevalence of parathyroid incidentalomas in patients referred for thyroid ultrasonography (US) and investigate the role of chronic thyroiditis on false positive lesions. Patients suspected to have parathyroid lesions during thyroid US were recorded prospectively between August 2009 and January 2010. Patients referred for parathyroid US and patients with known high serum calcium or parathyroid hormone (PTH) levels were excluded. Suspected parathyroid lesions were defined as hypoechoic, homogeneous, solid lesions with regular margins located outside the thyroid lobe, most commonly inferior to the thyroid gland. Thyroid US was performed in 6,528 patients. There were 78 patients (1.19 %) (73 female and 5 male) with suspected parathyroid lesion. The diagnosis of a true parathyroid adenoma was confirmed in 6 (7.69 %) patients. In patients with true adenoma, mean serum calcium, phosphorus, and PTH levels were 10.57 ± 0.48 mg/dl, 3.03 ± 0.52 mg/dl, and 182.91 ± 46.62 pg/ml, respectively. Among 72 patients with false positive parathyroid lesion, antithyroid peroxidase antibody was positive in 50 (69.4 %), antithyroglobulin antibody was positive in 46 (63.9 %), and one of these antibodies were positive in 59 (81.9 %) patients. Also, 46 (63.9 %) of these patients had thyroid dysfunctions (43 hypothyroidism and 3 hyperthyroidism) and 59 (81.9 %) had chronic thyroiditis ultrasonographically. Parathyroid incidentaloma was detected in 0.09 % of patients referred for thyroid US. The presence of clinically or ultrasonographically chronic thyroiditis might cause inadvertent interpretation of a hypoechoic lesion as a parathyroid pathology during thyroid US.

  7. Diagnosis and management of benign, atypical, and indeterminate breast lesions detected on core needle biopsy.

    PubMed

    Neal, Lonzetta; Sandhu, Nicole P; Hieken, Tina J; Glazebrook, Katrina N; Mac Bride, Maire Brid; Dilaveri, Christina A; Wahner-Roedler, Dietlind L; Ghosh, Karthik; Visscher, Daniel W

    2014-04-01

    Imaging abnormalities detected by mammographic screening often lead to diagnostic evaluations, with suspicious abnormalities subjected to image-guided core needle biopsy (CNB) to exclude malignancy. Most CNBs reveal benign pathological alterations, termed benign breast disease (BBD). Adoption of CNB presents challenges with pathologic classification of breast abnormalities and management of patients with benign or atypical histological findings. Patient management and counseling after CNB diagnosis of BBD depends on postbiopsy determination of radiologic-pathologic concordancy. Communication between radiologists and pathologists is crucial in patient management. Management is dependent on the histological type of BBD. Patients with concordant pathologic imaging results can be reassured of benign biopsy findings and advised about the future risk of developing breast cancer. Surgical consultation is advised for patients with discordant findings, symptomatic patients, and high-risk lesions. This review highlights benign breast lesions that are encountered on CNB and summarizes management strategies. For this review, we conducted a search of PubMed, with no date limitations, and used the following search terms (or a combination of terms): atypical ductal hyperplasia, atypical hyperplasia, atypical lobular hyperplasia, benign breast disease, cellular fibroepithelial lesions, columnar cell lesions, complex sclerosing lesion, core needle biopsy, fibroadenomas, flat epithelial atypia, lobular carcinoma in situ, lobular neoplasia, mucocele-like lesions, phyllodes tumor, pseudoangiomatous stromal hyperplasia, radial scar, and vascular lesions. The selection of references included in this review was based on study relevance and quality. We used additional articles culled from the bibliographies of retrieved articles to examine the published evidence for risk factors of BBD. Copyright © 2014 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All

  8. Risk Stratification of Neck Lesions Detected Sonographically During the Follow-Up of Differentiated Thyroid Cancer.

    PubMed

    Lamartina, Livia; Grani, Giorgio; Biffoni, Marco; Giacomelli, Laura; Costante, Giuseppe; Lupo, Stefania; Maranghi, Marianna; Plasmati, Katia; Sponziello, Marialuisa; Trulli, Fabiana; Verrienti, Antonella; Filetti, Sebastiano; Durante, Cosimo

    2016-08-01

    The European Thyroid Association (ETA) has classified posttreatment cervical ultrasound findings in thyroid cancer patients based on their association with disease persistence/recurrence. The objective of the study was to assess this classification's ability to predict the growth and persistence of such lesions during active posttreatment surveillance of patients with differentiated thyroid cancer (DTC). This was a retrospective, observational study. The study was conducted at a thyroid cancer center in a large Italian teaching hospital. Center referrals (2005-2014) were reviewed and patients selected with pathologically-confirmed DTC; total thyroidectomy, with or without neck dissection and/or radioiodine remnant ablation; abnormal findings on two or more consecutive posttreatment neck sonograms; and subsequent follow-up consisting of active surveillance. Baseline ultrasound abnormalities (thyroid bed masses, lymph nodes) were classified according to the ETA system. Patients were divided into group S (those with one or more lesions classified as suspicious) and group I (indeterminate lesions only). We recorded baseline and follow-up clinical data through June 30, 2015. The main outcomes were patients with growth (>3 mm, largest diameter) of one or more lesions during follow-up and patients with one or more persistent lesions at the final visit. The cohort included 58 of the 637 DTC cases screened (9%). A total of 113 lesions were followed up (18 thyroid bed masses, 95 lymph nodes). During surveillance (median 3.7 y), group I had significantly lower rates than group S of lesion growth (8% vs 36%, P = .01) and persistence (64% vs 97%, P = .014). The median time to scan normalization was 2.9 years. The ETA's evidence-based classification of sonographically detected neck abnormalities can help identify papillary thyroid cancer patients eligible for more relaxed follow-up.

  9. Automatic detection and segmentation of ischemic lesions in computed tomography images of stroke patients

    NASA Astrophysics Data System (ADS)

    Vos, Pieter C.; Biesbroek, J. Matthijs; Weaver, Nick A.; Velthuis, Birgitta K.; Viergever, Max A.

    2013-03-01

    Stroke is the third most common cause of death in developed countries. Clinical trials are currently investigating whether advanced Computed Tomography can be of benefit for diagnosing stroke at the acute phase. These trials are based on large patients cohorts that need to be manually annotated to obtain a reference standard of tissue loss at follow-up, resulting in extensive workload for the radiologists. Therefore, there is a demand for accurate and reliable automatic lesion segmentation methods. This paper presents a novel method for the automatic detection and segmentation of ischemic lesions in CT images. The method consists of multiple sequential stages. In the initial stage, pixel classification is performed using a naive Bayes classifier in combination with a tissue homogeneity algorithm in order to localize ischemic lesion candidates. In the next stage, the candidates are segmented using a marching cubes algorithm. Regional statistical analysis is used to extract features based on local information as well as contextual information from the contra-lateral hemisphere. Finally, the extracted features are summarized into a likelihood of ischemia by a supervised classifier. An area under the Receiver Operating Characteristic curve of 0.91 was obtained for the identification of ischemic lesions. The method performance on lesion segmentation reached a Dice similarity coeficient (DSC) of 0.74+/-0.09, whereas an independent human observer obtained a DSC of 0.79+/-0.11 in the same dataset. The experiments showed that it is feasible to automatically detect and segment ischemic lesions in CT images, obtaining a comparable performance as human observers.

  10. The impact of simulated motion blur on lesion detection performance in full-field digital mammography.

    PubMed

    Abdullah, Ahmed K; Kelly, Judith; Thompson, John D; Mercer, Claire E; Aspin, Rob; Hogg, Peter

    2017-07-01

    Motion blur is a known phenomenon in full-field digital mammography, but the impact on lesion detection is unknown. This is the first study to investigate detection performance with varying magnitudes of simulated motion blur. 7 observers (15 ± 5 years' reporting experience) evaluated 248 cases (62 containing malignant masses, 62 containing malignant microcalcifications and 124 normal cases) for 3 conditions: no blurring (0 mm) and 2 magnitudes of simulated blurring (0.7 and 1.5 mm). Abnormal cases were biopsy proven. Mathematical simulation was used to provide a pixel shift in order to simulate motion blur. A free-response observer study was conducted to compare lesion detection performance for the three conditions. The equally weighted jackknife alternative free-response receiver operating characteristic was used as the figure of merit. Test alpha was set at 0.05 to control probability of Type I error. The equally weighted jackknife alternative free-response receiver operating characteristic analysis found a statistically significant difference in lesion detection performance for both masses [F(2,22) = 6.01, p = 0.0084] and microcalcifications [F(2,49) = 23.14, p < 0.0001]. The figures of merit reduced as the magnitude of simulated blurring increased. Statistical differences were found between some of the pairs investigated for the detection of masses (0.0 vs 0.7 and 0.0 vs 1.5 mm) and all pairs for microcalcifications (0.0 vs 0.7, 0.0 vs 1.5 and 0.7 vs 1.5 mm). No difference was detected between 0.7 and 1.5 mm for masses. The mathematical simulation of motion blur caused a statistically significant reduction in lesion detection performance. These false-negative decisions could have implications for clinical practice. Advances in knowledge: This research demonstrates for the first time that motion blur has a negative and statistically significant impact on lesion detection performance in digital mammography.

  11. Immunohistochemical myofiber typing and high-resolution myofibrillar lesion detection in LR white embedded muscle

    NASA Technical Reports Server (NTRS)

    Thompson, J. L.; Vijayan, K.; Riley, D. A.

    2000-01-01

    We have developed a method of fixing, embedding, sectioning, and staining that allows high-resolution detection of myofibrillar structure and myosin immunocytochemical muscle fiber typing in serial semithin sections of LR White plastic embedded muscle at the light microscopic level. Traditional approaches, such as cryostat sections, permit fiber typing, but small myofibrillar lesions (1-3 sarcomeres) are difficult to detect because of section thickness. Semithin sections of hydrophobic resins do not stain well either histochemically or immunocytochemically. Electron microscopy can resolve lesions and discriminate fiber types based on morphology, but the sampling area is small. Our goal was to develop a rapid method for defining both fiber type and high-resolution primary myofibrillar lesion damage. Mild fixation (1-4% paraformaldehyde, 0. 05-0.1% glutaraldehyde) and embedment in a hydrophilic resin (LR White) were used. Myofibrillar structure was extremely well preserved at the light microscopic (LM) level, and lesions could be readily resolved in Toluidine blue stained 500-nm sections. Fiber type was defined by LM immunomyosin staining of serial plastic semithin sections, which demonstrated reciprocal staining patterns for "fast (Sigma M4276) and "total" (skeletal muscle) myosins (Sigma M7523). Copyright 2000 Wiley-Liss, Inc.

  12. Nakagami imaging for detecting thermal lesions induced by high-intensity focused ultrasound in tissue.

    PubMed

    Rangraz, Parisa; Behnam, Hamid; Tavakkoli, Jahan

    2014-01-01

    High-intensity focused ultrasound induces focalized tissue coagulation by increasing the tissue temperature in a tight focal region. Several methods have been proposed to monitor high-intensity focused ultrasound-induced thermal lesions. Currently, ultrasound imaging techniques that are clinically used for monitoring high-intensity focused ultrasound treatment are standard pulse-echo B-mode ultrasound imaging, ultrasound temperature estimation, and elastography-based methods. On the contrary, the efficacy of two-dimensional Nakagami parametric imaging based on the distribution of the ultrasound backscattered signals to quantify properties of soft tissue has recently been evaluated. In this study, ultrasound radio frequency echo signals from ex vivo tissue samples were acquired before and after high-intensity focused ultrasound exposures and then their Nakagami parameter and scaling parameter of Nakagami distribution were estimated. These parameters were used to detect high-intensity focused ultrasound-induced thermal lesions. Also, the effects of changing the acoustic power of the high-intensity focused ultrasound transducer on the Nakagami parameters were studied. The results obtained suggest that the Nakagami distribution's scaling and Nakagami parameters can effectively be used to detect high-intensity focused ultrasound-induced thermal lesions in tissue ex vivo. These parameters can also be used to understand the degree of change in tissue caused by high-intensity focused ultrasound exposures, which could be interpreted as a measure of degree of variability in scatterer concentration in various parts of the high-intensity focused ultrasound lesion.

  13. Immunohistochemical myofiber typing and high-resolution myofibrillar lesion detection in LR white embedded muscle

    NASA Technical Reports Server (NTRS)

    Thompson, J. L.; Vijayan, K.; Riley, D. A.

    2000-01-01

    We have developed a method of fixing, embedding, sectioning, and staining that allows high-resolution detection of myofibrillar structure and myosin immunocytochemical muscle fiber typing in serial semithin sections of LR White plastic embedded muscle at the light microscopic level. Traditional approaches, such as cryostat sections, permit fiber typing, but small myofibrillar lesions (1-3 sarcomeres) are difficult to detect because of section thickness. Semithin sections of hydrophobic resins do not stain well either histochemically or immunocytochemically. Electron microscopy can resolve lesions and discriminate fiber types based on morphology, but the sampling area is small. Our goal was to develop a rapid method for defining both fiber type and high-resolution primary myofibrillar lesion damage. Mild fixation (1-4% paraformaldehyde, 0. 05-0.1% glutaraldehyde) and embedment in a hydrophilic resin (LR White) were used. Myofibrillar structure was extremely well preserved at the light microscopic (LM) level, and lesions could be readily resolved in Toluidine blue stained 500-nm sections. Fiber type was defined by LM immunomyosin staining of serial plastic semithin sections, which demonstrated reciprocal staining patterns for "fast (Sigma M4276) and "total" (skeletal muscle) myosins (Sigma M7523). Copyright 2000 Wiley-Liss, Inc.

  14. The impact of breast structure on lesion detection in breast tomosynthesis

    NASA Astrophysics Data System (ADS)

    Kiarashi, Nooshin; Nolte, Loren W.; Lo, Joseph Y.; Segars, William P.; Ghate, Sujata V.; Samei, Ehsan

    2015-03-01

    Virtual clinical trials (VCT) can be carefully designed to inform, orient, or potentially replace clinical trials. The focus of this study was to demonstrate the capability of the sophisticated tools that can be used in the design, implementation, and performance analysis of VCTs, through characterization of the effect of background tissue density and heterogeneity on the detection of irregular masses in digital breast tomosynthesis. Twenty breast phantoms from the extended cardiactorso (XCAT) family, generated based on dedicated breast computed tomography of human subjects, were used to extract a total of 2173 volumes of interest (VOI) from simulated tomosynthesis images. Five different lesions, modeled after human subject tomosynthesis images, were embedded in the breasts, for a total of 6×2173 VOIs with and without lesions. Effects of background tissue density and heterogeneity on the detection of the lesions were studied by implementing a doubly composite hypothesis signal detection theory paradigm with location known exactly, lesion known exactly, and background known statistically. The results indicated that the detection performance as measured by the area under the receiver operating characteristic curve (ROC) deteriorated as density was increased, yielding findings consistent with clinical studies. The detection performance varied substantially across the twenty breasts. Furthermore, the log-likelihood ratio under H0 and H1 seemed to be affected by background tissue density and heterogeneity differently. Considering background tissue variability can change the outcomes of a VCT and is hence of crucial importance. The XCAT breast phantoms can address this concern by offering realistic modeling of background tissue variability based on a wide range of human subjects.

  15. Comparison of SPECT/CT and MRI in Diagnosing Symptomatic Lesions in Ankle and Foot Pain Patients: Diagnostic Performance and Relation to Lesion Type

    PubMed Central

    Ha, Seunggyun; Hong, Sung Hwan; Paeng, Jin Chul; Lee, Dong Yeon; Cheon, Gi Jeong; Arya, Amitabh; Chung, June-Key; Lee, Dong Soo; Kang, Keon Wook

    2015-01-01

    Purpose The purpose of this study was to compare the diagnostic performance of SPECT/CT and MRI in patients with ankle and foot pain, with regard to the lesion types. Materials and Methods Fifty consecutive patients with ankle and foot pain, who underwent 99mTc-MDP SPECT/CT and MRI, were retrospectively enrolled in this study. Symptomatic lesions were determined based on clinical examination and response to treatment. On MRI and SPECT/CT, detected lesions were classified as bone, ligament/tendon, and joint lesions. Uptake on SPECT/CT was assessed using a 4-grade system. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of SPECT/CT and MRI were evaluated in all detected lesions and each lesion type. Diagnostic value of uptake grade was analyzed using receiver-operating characteristics (ROC) curve analysis, and diagnostic performance was compared using Chi-square or McNemar tests. Results In overall lesions, the sensitivity, PPV and NPV of SPECT/CT for symptomatic lesions were 93%, 56%, 91%, and they were 98%, 48%, 95% for MRI. There was no significant difference between SPECT/CT and MRI. However, the specificity of SPECT/CT was significantly higher than that of MRI (48% versus 24%, P = 0.016). Uptake grade on SPECT/CT was significantly higher in symptomatic lesions (P < 0.001), and its area under curve on ROC analysis was 0.787. In the analysis of each lesion type, the specificity of SPECT/CT was poor in joint lesions compared with other lesion types and MRI (P < 0.001, respectively). MRI exhibited lower specificity than SPECT/CT in bone lesions (P = 0.004) and ligament/tendon lesions (P < 0.001). Conclusions SPECT/CT has MRI-comparable diagnostic performance for symptomatic lesions in ankle and foot pain patients. SPECT/CT and MRI exhibit different diagnostic specificity in different lesion types. SPECT/CT may be used as a complementary imaging method to MRI for enhancing diagnostic specificity. PMID:25668182

  16. Focal liver lesions at 3.0 T: lesion detectability and image quality with T2-weighted imaging by using conventional and dual-source parallel radiofrequency transmission.

    PubMed

    Kukuk, Guido M; Gieseke, Jürgen; Weber, Sebastian; Hadizadeh, Dariusch R; Nelles, Michael; Träber, Frank; Schild, Hans H; Willinek, Winfried A

    2011-05-01

    To prospectively compare T2-weighted single-shot turbo spin-echo (TSE) sequences performed with parallel and conventional radiofrequency (RF) transmission at 3.0 T for liver lesion detection, image quality, lesion conspicuity, and lesion contrast. After written informed consent and institutional review board approval, 52 consecutive patients (32 men, 20 women; mean age, 56.6 years ± 13.7 [standard deviation]) underwent routine magnetic resonance (MR) imaging with a clinical 3.0-T unit. Two independent readers reviewed images acquired with conventional and dual-source parallel RF transmission for detection of focal liver lesions, with separate reading of a third radiologist, including all available imaging findings, clinical history, and histopathologic findings, as reference. Image quality and lesion conspicuity were rated on five- and three-point evaluation scales, respectively. Contrast ratios between focal liver lesions and adjacent liver parenchyma were calculated. Significance was determined by using nonparametric Wilcoxon signed-rank and marginal homogeneity tests. With the reference standard, 106 index lesions were identified in 22 patients. Detection rate significantly improved from 87% (92 of 106) to 97% (103 of 106) (reader 1) and from 85% (90 of 106) to 96% (102 of 106) (reader 2) with parallel RF transmission (reader 1, P = .0078; reader 2, P = .002). Quality of parallel RF transmission images was assigned scores significantly higher, compared with quality of conventional RF transmission images (mean for reader 1, 2.88 ± 0.73 vs 4.04 ± 0.44; mean for reader 2, 2.81 ± 0.72 vs 4.04 ± 0.39; P < .0001 for both). Lesion conspicuity scores were significantly higher on parallel RF transmission images, compared with conventional RF transmission images (mean for reader 1, 2.02 ± 0.64 vs 2.92 ± 0.27; mean for reader 2, 2.06 ± 0.67 vs 2.90 ± 0.30; P < .0001 for both). Contrast ratios were significantly higher with parallel RF transmission (P < .05

  17. What proportions of focal liver lesions detected by unenhanced ultrasound are inconclusive?

    PubMed Central

    Willits, Iain; Burn, Julie; Cole, Helen; Hoare, Tim

    2014-01-01

    In August 2012, the National Institute for Health and Care Excellence produced positive diagnostics guidance on the ultrasound contrast agent SonoVue®, but recommended further research involving an estimation of the proportion of unenhanced ultrasound scans reporting, but not characterising, focal liver lesions, particularly in cirrhotic livers. Patient records from the Radiology Information System of an acute hospital trust were progressively filtered based on categorical fields and keywords in the free text reports, to obtain ultrasound records including the liver that were appropriate for manual analysis. In total, 21,731 records referred from general practice or out-patient clinics were analysed. Patients described as having cirrhosis were analysed as a subgroup. After automatic exclusion of records considered likely to be negative, 5812 records were manually read and categorised as focal liver lesion inconclusive, benign or malignant. In the general practice cohort of 9175 records, 746 reported the presence of one or more focal liver lesions, with 18.4% (95% CI 15.7% to 21.3%) of these records mentioning an inconclusive focal liver lesion. In the out-patient cohort of 12,556 records, 1437 reported one or more focal liver lesions, and 29.4% (95% CI 26.9% to 32.0%) of these were inconclusive. Cirrhosis was reported in 10.8% of the out-patient scans that also reported a focal liver lesion, and 47.4% (95% CI 39.3% to 55.6%) of these scans had an inconclusive focal liver lesion, compared with 27.3% (95% CI 24.9% to 29.8%) that were inconclusive in non-cirrhotic livers (odds ratio 2.4; 95% CI 1.7 to 3.4). This retrospective study indicates that unenhanced ultrasound scans, in which a focal liver lesion is detected, are frequently inconclusive, with the probability of an inconclusive scan being greater in out-patient than general practice referrals. Inconclusive focal liver lesions were also reported in greater proportions of cirrhotic than non-cirrhotic livers. The

  18. On the relationship of minimum detectable contrast to dose and lesion size in abdominal CT

    NASA Astrophysics Data System (ADS)

    Zhou, Yifang; Scott, Alexander, II; Allahverdian, Janet; Lee, Christina; Kightlinger, Blake; Azizyan, Avetis; Miller, Joseph

    2015-10-01

    CT dose optimization is typically guided by pixel noise or contrast-to-noise ratio that does not delineate low contrast details adequately. We utilized the statistically defined low contrast detectability to study its relationship to dose and lesion size in abdominal CT. A realistically shaped medium sized abdomen phantom was customized to contain a cylindrical void of 4 cm diameter. The void was filled with a low contrast (1% and 2%) insert containing six groups of cylindrical targets ranging from 1.2 mm to 7 mm in size. Helical CT scans were performed using a Siemens 64-slice mCT and a GE Discovery 750 HD at various doses. After the subtractions between adjacent slices, the uniform sections of the filtered backprojection reconstructed images were partitioned to matrices of square elements matching the sizes of the targets. It was verified that the mean values from all the elements in each matrix follow a Gaussian distribution. The minimum detectable contrast (MDC), quantified by the mean signal to background difference equal to the distribution’s standard deviation multiplied by 3.29, corresponding to 95% confidence level, was found to be related to the phantom specific dose and the element size by a power law (R^2  >  0.990). Independent readings on the 5 mm and 7 mm targets were compared to the measured contrast to the MDC ratios. The results showed that 93% of the cases were detectable when the measured contrast exceeds the MDC. The correlation of the MDC to the pixel noise and target size was also identified and the relationship was found to be the same for the scanners in the study. To quantify the impact of iterative reconstructions to the low contrast detectability, the noise structure was studied in a similar manner at different doses and with different ASIR blending fractions. The relationship of the dose to the blending fraction and low contrast detectability is presented.

  19. On the relationship of minimum detectable contrast to dose and lesion size in abdominal CT.

    PubMed

    Zhou, Yifang; Scott, Alexander; Allahverdian, Janet; Lee, Christina; Kightlinger, Blake; Azizyan, Avetis; Miller, Joseph

    2015-10-07

    CT dose optimization is typically guided by pixel noise or contrast-to-noise ratio that does not delineate low contrast details adequately. We utilized the statistically defined low contrast detectability to study its relationship to dose and lesion size in abdominal CT. A realistically shaped medium sized abdomen phantom was customized to contain a cylindrical void of 4 cm diameter. The void was filled with a low contrast (1% and 2%) insert containing six groups of cylindrical targets ranging from 1.2 mm to 7 mm in size. Helical CT scans were performed using a Siemens 64-slice mCT and a GE Discovery 750 HD at various doses. After the subtractions between adjacent slices, the uniform sections of the filtered backprojection reconstructed images were partitioned to matrices of square elements matching the sizes of the targets. It was verified that the mean values from all the elements in each matrix follow a Gaussian distribution. The minimum detectable contrast (MDC), quantified by the mean signal to background difference equal to the distribution's standard deviation multiplied by 3.29, corresponding to 95% confidence level, was found to be related to the phantom specific dose and the element size by a power law (R^2  >  0.990). Independent readings on the 5 mm and 7 mm targets were compared to the measured contrast to the MDC ratios. The results showed that 93% of the cases were detectable when the measured contrast exceeds the MDC. The correlation of the MDC to the pixel noise and target size was also identified and the relationship was found to be the same for the scanners in the study. To quantify the impact of iterative reconstructions to the low contrast detectability, the noise structure was studied in a similar manner at different doses and with different ASIR blending fractions. The relationship of the dose to the blending fraction and low contrast detectability is presented.

  20. Oral precancerous lesions: Problems of early detection and oral cancer prevention

    NASA Astrophysics Data System (ADS)

    Gileva, Olga S.; Libik, Tatiana V.; Danilov, Konstantin V.

    2016-08-01

    The study presents the results of the research in the structure, local and systemic risk factors, peculiarities of the clinical manifestation, and quality of primary diagnosis of precancerous oral mucosa lesions (OMLs). In the study a wide range of OMLs and high (25.4%) proportion of oral precancerous lesions (OPLs) in their structure was indicated. The high percentage of different diagnostic errors and the lack of oncological awareness of dental practitioners, as well as the sharp necessity of inclusion of precancer/cancer early detection techniques into their daily practice were noted. The effectiveness of chemilumenescence system of early OPLs and oral cancer detection was demonstrated, the prospects of infrared thermography as a diagnostic tool were also discussed.

  1. Risk factors for denture-related oral mucosal lesions in a geriatric population.

    PubMed

    Martori, Elisenda; Ayuso-Montero, Raul; Martinez-Gomis, Jordi; Viñas, Miguel; Peraire, Maria

    2014-04-01

    Denture-related mucosal lesions have been broadly studied. However, no consensus has been reached regarding the risk factors associated with these lesions, and few studies have used multivariable analysis to determine the relative significance of different risks. The purpose of this study was to determine the relationship between systemic, local, and denture factors on the risk of denture-related oral mucosal lesions in an elderly population by using multivariable analysis. Eighty-four elderly denture wearers recruited from geriatric residences and day care centers participated in this cross-sectional study. All data were obtained by means of a questionnaire-interview, a physical examination, and complementary tests. Bivariate relationship and multiple logistic regression analyses were performed (α=.05). Angular cheilitis (34%), traumatic ulcers (15%), and denture stomatitis (14%) were the 3 most common lesions, and the prevalence of at least 1 denture-related mucosal lesion was 54%. The presence of denture stomatitis was related to low saliva pH, never having smoked, and regular sugar consumption. Angular cheilitis was associated with age, complete edentulism, the presence of oral Candida, a lack of denture stability, and a reduced occlusal vertical dimension. The presence of traumatic ulcers was related to a resorbed residual alveolar ridge. The presence of at least 1 lesion was associated with poor masticatory efficiency, being resident in a care facility, oral Candida, and a lack of denture stability. Several systemic, local, and denture-related characteristics are independent risk factors for denture-related mucosal lesions in an elderly population. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  2. Coordinating Center: Molecular and Cellular Findings of Screen-Detected Lesions | Division of Cancer Prevention

    Cancer.gov

    DESCRIPTION (provided by applicant): The Molecular and Cellular Characterization of Screen‐Detected Lesions ‐ Coordinating Center and Data Management Group will provide support for the participating studies responding to RFA CA14‐10. The coordinating center supports three main domains: network coordination, statistical support and computational analysis and protocol development and database support. Support for communication is provided through an interactive web portal, management of conference calls, and meeting support. |

  3. Noninvasive Real-Time Automated Skin Lesion Analysis System for Melanoma Early Detection and Prevention

    PubMed Central

    Abuzaghleh, Omar; Barkana, Buket D.

    2015-01-01

    Melanoma spreads through metastasis, and therefore, it has been proved to be very fatal. Statistical evidence has revealed that the majority of deaths resulting from skin cancer are as a result of melanoma. Further investigations have shown that the survival rates in patients depend on the stage of the cancer; early detection and intervention of melanoma implicate higher chances of cure. Clinical diagnosis and prognosis of melanoma are challenging, since the processes are prone to misdiagnosis and inaccuracies due to doctors’ subjectivity. Malignant melanomas are asymmetrical, have irregular borders, notched edges, and color variations, so analyzing the shape, color, and texture of the skin lesion is important for the early detection and prevention of melanoma. This paper proposes the two major components of a noninvasive real-time automated skin lesion analysis system for the early detection and prevention of melanoma. The first component is a real-time alert to help users prevent skinburn caused by sunlight; a novel equation to compute the time for skin to burn is thereby introduced. The second component is an automated image analysis module, which contains image acquisition, hair detection and exclusion, lesion segmentation, feature extraction, and classification. The proposed system uses PH2 Dermoscopy image database from Pedro Hispano Hospital for the development and testing purposes. The image database contains a total of 200 dermoscopy images of lesions, including benign, atypical, and melanoma cases. The experimental results show that the proposed system is efficient, achieving classification of the benign, atypical, and melanoma images with accuracy of 96.3%, 95.7%, and 97.5%, respectively. PMID:27170906

  4. Optical detection of (pre-)malignant lesions of the oral mucosa: autofluorescence characteristics of healthy mucosa

    NASA Astrophysics Data System (ADS)

    de Veld, Diana C. G.; Witjes, Max; Roodenburg, Jan L.; Star, Willem M.; Sterenborg, Hericus J. C. M.

    2001-10-01

    Previous clinical results demonstrate the potential of in vivo autofluorescence spectroscopy for early detection of (pre-)malignant lesions of the oral mucosa. For reliable diagnosis, it is necessary to study autofluorescence spectra of healthy mucosa first. We measured excitation-emission maps in healthy subjects and subjects with a history of cancer in the head -neck region. Our results show that different anatomical locations produce distinct autofluorescence spectra. Influences of, among others, smoking and drinking habits require further investigation.

  5. Standard examination and adjunctive techniques for detection of oral premalignant and malignant lesions.

    PubMed

    Kerr, A Ross; Shah, Sonal S

    2013-05-01

    This article outlines how to perform a standard comprehensive extraoral and intraoral examination and the existing commercially available adjunctive techniques for the early detection of oral cancer and premalignant lesions. Visualization-based techniques (e.g., autofluorescence and chemiluminescence), toluidine blue vital staining, cytopathologic tests and high-risk human papillomavirus testing are discussed in detail, including the indications and protocols for use, their advantages and disadvantages and clinical cases.

  6. The Effect of Susceptibility Artifacts Related to Metallic Implants on Adjacent-Lesion Assessment in Simultaneous TOF PET/MR.

    PubMed

    Svirydenka, Hanna; Delso, Gaspar; De Galiza Barbosa, Felipe; Huellner, Martin; Davison, Helen; Fanti, Stefano; Veit-Haibach, Patrick; Ter Voert, Edwin E G W

    2017-07-01

    Metalic implants may affect attenuation correction (AC) in PET/MR imaging. The purpose of this study was to evaluate the effect of susceptibility artifacts related to metallic implants on adjacent metabolically active lesions in clinical simultaneous PET/MR scanning for both time-of-flight (TOF) and non-TOF reconstructed PET images. Methods: We included 27 patients without implants but with confirmed (18)F-FDG-avid lesions adjacent to common implant locations. In all patients, a clinically indicated whole-body (18)F-FDG PET/MR scan was acquired. Baseline non-TOF and TOF PET images were reconstructed. Reconstruction was repeated after the introduction of artificial signal voids in the AC map to simulate metallic implants in standard anatomic areas. All reconstructed images were qualitatively and quantitatively assessed and compared with the baseline images. Results: In total, 51 lesions were assessed. In 40 and 50 of these cases (non-TOF and TOF, respectively), the detectability of the lesions did not change; in 9 and 1 cases, the detectability changed; and in 2 non-TOF cases, the lesions were no longer visible after the introduction of metallic artifacts. The inclusion of TOF information significantly reduced artifacts due to simulated implants in the femoral head, sternum, and spine (P = 0.01, 0.01, and 0.03, respectively). It also improved image quality in these locations (P = 0.02, 0.01, and 0.01, respectively). The mean percentage error was -3.5% for TOF and -4.8% for non-TOF reconstructions, meaning that the inclusion of TOF information reduced the percentage error in SUVmax by 28.5% (P < 0.01). Conclusion: Qualitatively, there was a significant reduction of artifacts in the femoral head, sternum, and spine. There was also a significant qualitative improvement in image quality in these locations. Furthermore, our study indicated that simulated susceptibility artifacts related to metallic implants have a significant effect on small, moderately (18)F

  7. Histopathological study of cardiac lesions in methamphetamine poisoning-related deaths.

    PubMed

    Akhgari, Maryam; Mobaraki, Homeira; Etemadi-Aleagha, Afshar

    2017-02-17

    Methamphetamine abuse is a worldwide health concern. Methamphetamine causes health hazards in many vital organs. It can cause damage to cardiac tissue via catecholamines release. Methamphetamine related deaths are becoming one of the most important problems in Iran. The purpose of the present study was to determine cardiac pathology in methamphetamine poisoning-related deaths. The study included 100 cases of methamphetamine poisoning-related deaths and 100 cases as control group. Toxicology analysis of liver, gastric content, bile, urine, blood and vitreous humor were conducted to detect drugs, poisons and alcohols using thin layer chromatography, gas chromatography/mass spectrometry, and high performance liquid chromatography. Positive toxicology analysis results except for amphetamine and methamphetamine were excluded from the study in order to omit interfering factors. The most striking features of cardiac damage were observed by light microscopy. Methamphetamine and amphetamine were detected in either urine or gastric content samples. In all of the cases methamphetamine toxicity was determined to be a direct cause of death by forensic medicine practitioner. Cardiovascular pathology was noted in 68% of studied cases. The most common histopathologic features were myocardial fiber hypertrophy, mild, moderate to severe atherosclerosis and focal degeneration/necrosis. The results of the present study indicate that cardiotoxicity is one of the major contributing factors in methamphetamine poisoning related deaths. Overall, the current study highlights the fact that cardiotoxic effects of methamphetamine can explain increasing reports of heart failure and consequently death in young abusers. Not applicable. Histopathological study of cardiac lesions in methamphetamine poisoning-related deaths.

  8. Automatic detection and recognition of multiple macular lesions in retinal optical coherence tomography images with multi-instance multilabel learning

    NASA Astrophysics Data System (ADS)

    Fang, Leyuan; Yang, Liumao; Li, Shutao; Rabbani, Hossein; Liu, Zhimin; Peng, Qinghua; Chen, Xiangdong

    2017-06-01

    Detection and recognition of macular lesions in optical coherence tomography (OCT) are very important for retinal diseases diagnosis and treatment. As one kind of retinal disease (e.g., diabetic retinopathy) may contain multiple lesions (e.g., edema, exudates, and microaneurysms) and eye patients may suffer from multiple retinal diseases, multiple lesions often coexist within one retinal image. Therefore, one single-lesion-based detector may not support the diagnosis of clinical eye diseases. To address this issue, we propose a multi-instance multilabel-based lesions recognition (MIML-LR) method for the simultaneous detection and recognition of multiple lesions. The proposed MIML-LR method consists of the following steps: (1) segment the regions of interest (ROIs) for different lesions, (2) compute descriptive instances (features) for each lesion region, (3) construct multilabel detectors, and (4) recognize each ROI with the detectors. The proposed MIML-LR method was tested on 823 clinically labeled OCT images with normal macular and macular with three common lesions: epiretinal membrane, edema, and drusen. For each input OCT image, our MIML-LR method can automatically identify the number of lesions and assign the class labels, achieving the average accuracy of 88.72% for the cases with multiple lesions, which better assists macular disease diagnosis and treatment.

  9. Lectin-functionalized mesoporous silica nanoparticles for endoscopic detection of premalignant colonic lesions.

    PubMed

    Chen, Nai-Tzu; Souris, Jeffrey S; Cheng, Shih-Hsun; Chu, Chia-Hui; Wang, Yu-Chao; Konda, Vani; Dougherty, Urszula; Bissonnette, Marc; Mou, Chung-Yuan; Chen, Chin-Tu; Lo, Leu-Wei

    2017-08-01

    Colorectal cancer (CRC) is one of the leading causes of cancer-deaths worldwide. Methods for the early in situ detection of colorectal adenomatous polyps and their precursors - prior to their malignancy transformation into CRC - are urgently needed. Unfortunately at present, the primary diagnostic method, colonoscopy, can only detect polyps and carcinomas by shape/morphology; with sessile polyps more likely to go unnoticed than polypoid lesions. Here we describe our development of polyp-targeting, fluorescently-labeled mesoporous silica nanoparticles (MSNs) that serve as targeted endoscopic contrast agents for the early detection of colorectal polyps and cancer. In vitro cell studies, ex vivo histopathological analysis, and in vivo colonoscopy and endoscopy of murine colorectal cancer models, demonstrate significant binding specificity of our nanoconstructs to pathological lesions via targeting aberrant α-L-fucose expression. Our findings strongly suggest that lectin-functionalized fluorescent MSNs could serve as a promising endoscopic contrast agent for in situ diagnostic imaging of premalignant colonic lesions. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Detection of questionable occlusal carious lesions using an electrical bioimpedance method with fractional electrical model

    NASA Astrophysics Data System (ADS)

    Morais, A. P.; Pino, A. V.; Souza, M. N.

    2016-08-01

    This in vitro study evaluated the diagnostic performance of an alternative electric bioimpedance spectroscopy technique (BIS-STEP) detect questionable occlusal carious lesions. Six specialists carried out the visual (V), radiography (R), and combined (VR) exams of 57 sound or non-cavitated occlusal carious lesion teeth classifying the occlusal surfaces in sound surface (H), enamel caries (EC), and dentinal caries (DC). Measurements were based on the current response to a step voltage excitation (BIS-STEP). A fractional electrical model was used to predict the current response in the time domain and to estimate the model parameters: Rs and Rp (resistive parameters), and C and α (fractional parameters). Histological analysis showed caries prevalence of 33.3% being 15.8% hidden caries. Combined examination obtained the best traditional diagnostic results with specificity = 59.0%, sensitivity = 70.9%, and accuracy = 60.8%. There were statistically significant differences in bioimpedance parameters between the H and EC groups (p = 0.016) and between the H and DC groups (Rs, p = 0.006; Rp, p = 0.022, and α, p = 0.041). Using a suitable threshold for the Rs, we obtained specificity = 60.7%, sensitivity = 77.9%, accuracy = 73.2%, and 100% of detection for deep lesions. It can be concluded that BIS-STEP method could be an important tool to improve the detection and management of occlusal non-cavitated primary caries and pigmented sites.

  11. Pre-envelope deconvolution for increased lesion detection efficiency in ultrasonic imaging

    NASA Astrophysics Data System (ADS)

    Abbey, Craig K.; Zemp, Roger J.; Insana, Michael F.

    2003-05-01

    We use an ideal observer model to evaluate the efficiency of human observers detecting a simulated lesion in the presence of speckle, and the ability of pre-envelope deconvolution to improve performance in this task. We model the lesion as a localized area of increased scatter density, which translates into an area of higher variance in the ultrasound signal. Assuming the scattering function and electronic noise obey Gaussian distributions, the ideal observer for lesion detection is given by a quadratic function of the in-phase (I) and quadrature (Q) data. For comparison, human-observer performance is assessed through two-alternative forced-choice (2AFC) psychophysical studies after making a B-mode image by computing the magnitude (envelope) of the I and Q components. We also consider the effect of removing spatial correlations in the I and Q components, before computing the magnitude (pre-envelope deconvolution). Our Psychophysical studies indicate approximately a 4-fold improvement in detection efficiency with pre-envelope deconvolution.

  12. Detection of questionable occlusal carious lesions using an electrical bioimpedance method with fractional electrical model

    SciTech Connect

    Morais, A. P.; Pino, A. V.; Souza, M. N.

    2016-08-15

    This in vitro study evaluated the diagnostic performance of an alternative electric bioimpedance spectroscopy technique (BIS-STEP) detect questionable occlusal carious lesions. Six specialists carried out the visual (V), radiography (R), and combined (VR) exams of 57 sound or non-cavitated occlusal carious lesion teeth classifying the occlusal surfaces in sound surface (H), enamel caries (EC), and dentinal caries (DC). Measurements were based on the current response to a step voltage excitation (BIS-STEP). A fractional electrical model was used to predict the current response in the time domain and to estimate the model parameters: Rs and Rp (resistive parameters), and C and α (fractional parameters). Histological analysis showed caries prevalence of 33.3% being 15.8% hidden caries. Combined examination obtained the best traditional diagnostic results with specificity = 59.0%, sensitivity = 70.9%, and accuracy = 60.8%. There were statistically significant differences in bioimpedance parameters between the H and EC groups (p = 0.016) and between the H and DC groups (Rs, p = 0.006; Rp, p = 0.022, and α, p = 0.041). Using a suitable threshold for the Rs, we obtained specificity = 60.7%, sensitivity = 77.9%, accuracy = 73.2%, and 100% of detection for deep lesions. It can be concluded that BIS-STEP method could be an important tool to improve the detection and management of occlusal non-cavitated primary caries and pigmented sites.

  13. Association between traumatic brain injury-related brain lesions and long-term caregiver burden

    PubMed Central

    Brioschi Guevara, Andrea; Demonet, Jean-Francois; Polejaeva, Elena; Knutson, Kristine M.; Wassermann, Eric M.; Grafman, Jordan; Krueger, Frank

    2015-01-01

    Objective To investigate the association between traumatic brain injury (TBI) related brain lesions and long-term caregiver burden in relation to dysexecutive syndrome. Setting National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland. Participants A total of 256 participants: 105 combat veterans with TBI, 23 healthy control combat veterans (HCv), and 128 caregivers. Outcome Measure Caregiver burden assessed by the Zarit Burden Interview (ZBI) at 40 years post-injury. Design Participants with penetrating TBI were compared with HCv on perceived caregiver burden and neuropsychological assessment measures. Data of Computed Tomography scans (overlay lesion maps of participants with a penetrating TBI whose caregivers have a significantly high burden) and behavioral statistical analyses were combined to identify brain lesions associated with caregiver burden. Results Burden was greater in caregivers of veterans with TBI than caregivers of HCv. Caregivers of participants with lesions affecting cognitive and behavioral indicators of dysexecutive syndrome (i.e., left dorsolateral prefrontal cortex and dorsal anterior cingulate cortex) showed greater long-term burden than caregivers of participants with lesions elsewhere in the brain. Conclusion and Implication TBI-related brain lesions have a lasting effect on long-term caregiver burden due to cognitive and behavioral factors associated with dysexecutive syndrome. PMID:26098258

  14. In vitro study on tooth enamel lesions related to whitening dentifrice.

    PubMed

    de Araújo, Danilo Barral; Silva, Luciana Rodrigues; Campos, Elisângela de Jesus; Correia de Araújo, Roberto Paulo

    2011-01-01

    The tooth whitening substances for extrinsic use that are available in Brazil contain hydrogen peroxide or carbamide peroxide. Several studies have attributed the appearance of lesions in the enamel morphology, including hypersensitivity, to these substances. Such lesions justify fluoride therapy and application of infrared lasers, among other procedures. However, there is no consensus among researchers regarding the relevance of the severity of lesions detected on the tooth surface. The present study was carried out with an aim of evaluating in vitro the effects of the hydrogen peroxide, carbamide peroxide and sodium bicarbonate contained in dentifrice formulations, on human tooth enamel. After darkening process in laboratory, human premolars were brushed using dentifrice containing the two whitening substances (Rembrandt - carbamide peroxide and Mentadent - hydrogen peroxide) and the abrasive product (Colgate - sodium bicarbonate). The degree of specimen staining before and after this procedure was determined using spectrophotometry. Scanning electron microscopy (SEM) was used to obtain images, which were analyzed to show the nature of the lesions that appeared on the enamel surface. The effectiveness of the whitening caused by hydrogen peroxide and carbamide peroxide and the abrasion caused by bicarbonate were confirmed, given that the treated test pieces returned to their original coloration. Based on SEM, evaluation of the enamel surfaces subjected to the test products showed that different types of morphologic lesions of varying severity appeared. Whitening dentifrice containing hydrogen peroxide and carbamide peroxide produced lesions on the enamel surface such that the greatest sequelae were associated with exposure to hydrogen peroxide.

  15. Random forest learning of ultrasonic statistical physics and object spaces for lesion detection in 2D sonomammography

    NASA Astrophysics Data System (ADS)

    Sheet, Debdoot; Karamalis, Athanasios; Kraft, Silvan; Noël, Peter B.; Vag, Tibor; Sadhu, Anup; Katouzian, Amin; Navab, Nassir; Chatterjee, Jyotirmoy; Ray, Ajoy K.

    2013-03-01

    Breast cancer is the most common form of cancer in women. Early diagnosis can significantly improve lifeexpectancy and allow different treatment options. Clinicians favor 2D ultrasonography for breast tissue abnormality screening due to high sensitivity and specificity compared to competing technologies. However, inter- and intra-observer variability in visual assessment and reporting of lesions often handicaps its performance. Existing Computer Assisted Diagnosis (CAD) systems though being able to detect solid lesions are often restricted in performance. These restrictions are inability to (1) detect lesion of multiple sizes and shapes, and (2) differentiate between hypo-echoic lesions from their posterior acoustic shadowing. In this work we present a completely automatic system for detection and segmentation of breast lesions in 2D ultrasound images. We employ random forests for learning of tissue specific primal to discriminate breast lesions from surrounding normal tissues. This enables it to detect lesions of multiple shapes and sizes, as well as discriminate between hypo-echoic lesion from associated posterior acoustic shadowing. The primal comprises of (i) multiscale estimated ultrasonic statistical physics and (ii) scale-space characteristics. The random forest learns lesion vs. background primal from a database of 2D ultrasound images with labeled lesions. For segmentation, the posterior probabilities of lesion pixels estimated by the learnt random forest are hard thresholded to provide a random walks segmentation stage with starting seeds. Our method achieves detection with 99.19% accuracy and segmentation with mean contour-to-contour error < 3 pixels on a set of 40 images with 49 lesions.

  16. Association between power law coefficients of the anatomical noise power spectrum and lesion detectability in breast imaging modalities

    NASA Astrophysics Data System (ADS)

    Chen, Lin; Abbey, Craig K.; Boone, John M.

    2013-03-01

    breast diameter, parameters both related to breast density. In all associations between other parameters, lower values of β were associated with increased breast cancer detection performance. Specifically, lower values of β were associated with lower breast density, higher detectability index, higher sensitivity, and lower fractal dimension values. While causality was not and probably cannot be demonstrated, the strong, statistically significant association between the β metric and the other more widely used parameters suggest that β may be considered as a surrogate measure for breast cancer detection performance. These findings are specific to breast parenchymal patterns and mass lesions only.

  17. Electron microscopic detection of human papillomavirus particles in oral proliferative lesions.

    PubMed

    Broich, G; Sasaki, T

    1989-11-01

    Human papilloma virus (HPV) has been demonstrated in a series of benign proliferative lesions of skin and mucosae. To prove the distribution of HPV in the oral proliferative lesions at the ultrastructural level, we performed electron microscopic analysis of 10 specimens taken from 5 patients through large excisional biopsy. All of them were diagnosed pathologically as fibropapilloma. In each patient, specimens were taken from both clinically evident proliferative lesions and clinically normal surrounding mucosa. Obtained specimens were fixed in a glutaraldehyde solution and processed for routine ultrathin sectioning. Before electron microscopic observation, the tissue sections on copper grids were subjected to amylase digestion of glycogen granules. Spherical viral particles of 40-55 nm in diameter were detected the non-keratinized epithelial cells in all specimens examined. Of particular interest were the large amounts of viral particles found in the cytoplasmic matrix and nuclei (especially on their chromatin masses) of the cells in intermediate and surface layers, which did not form a crystal array. All the membranous cell organelles of epithelial cells were, however, devoid of viral particles. Some viral particles were distributed in the extracellular spaces of an intermediate layer. Viral particles were hardly observed in the cells of a basal/suprabasal and prickle cell layers. There were no significant differences in the HPV distribution between the cells derived from the proliferative lesion and those derived from the surrounding normal mucosa.

  18. A Fillable Micro-Hollow Sphere Lesion Detection Phantom Using Superposition

    PubMed Central

    DiFilippo, Frank P.; Gallo, Sven L.; Klatte, Ryan S.; Patel, Sagar

    2010-01-01

    The lesion detection performance of SPECT and PET scanners is most commonly evaluated with a phantom containing hollow spheres in a background chamber at a specified radionuclide contrast ratio. However there are limitations associated with a miniature version of a hollow sphere phantom for small animal SPECT and PET scanners. One issue is that the “wall effect” associated with zero activity in the sphere wall and fill port causes significant errors for small diameter spheres. Another issue is that there are practical difficulties in fabricating and in filling very small spheres (< 3 mm diameter). The need for lesion detection performance assessment of small-animal scanners has motivated our development of a micro-hollow sphere phantom that utilizes the principle of superposition. The phantom is fabricated by stereolithography and has interchangeable sectors containing hollow spheres with volumes ranging from 1 to 14 μL (diameters ranging from 1.25 to 3.0 mm). A simple 60° internal rotation switches the positions of three such sectors with their corresponding background regions. Raw data from scans of each rotated configuration are combined and reconstructed to yield superposition images. Since the sphere counts and background counts are acquired separately, the wall effect is eliminated. The raw data are subsampled randomly prior to summation and reconstruction to specify the desired spheres-to-background contrast ratio of the superposition image. A set of images with multiple contrast ratios is generated for visual assessment of lesion detection thresholds. To demonstrate the utility of the phantom, data were acquired with a multi-pinhole SPECT/CT scanner. Micro-liter syringes were successful in filling the small hollow spheres, and the accuracy of the dispensed volume was validated through repeated filling and weighing of the spheres. The phantom’s internal rotation and the data analysis process were successful in producing the expected superposition

  19. Pigmented skin lesion detection using random forest and wavelet-based texture

    NASA Astrophysics Data System (ADS)

    Hu, Ping; Yang, Tie-jun

    2016-10-01

    The incidence of cutaneous malignant melanoma, a disease of worldwide distribution and is the deadliest form of skin cancer, has been rapidly increasing over the last few decades. Because advanced cutaneous melanoma is still incurable, early detection is an important step toward a reduction in mortality. Dermoscopy photographs are commonly used in melanoma diagnosis and can capture detailed features of a lesion. A great variability exists in the visual appearance of pigmented skin lesions. Therefore, in order to minimize the diagnostic errors that result from the difficulty and subjectivity of visual interpretation, an automatic detection approach is required. The objectives of this paper were to propose a hybrid method using random forest and Gabor wavelet transformation to accurately differentiate which part belong to lesion area and the other is not in a dermoscopy photographs and analyze segmentation accuracy. A random forest classifier consisting of a set of decision trees was used for classification. Gabor wavelets transformation are the mathematical model of visual cortical cells of mammalian brain and an image can be decomposed into multiple scales and multiple orientations by using it. The Gabor function has been recognized as a very useful tool in texture analysis, due to its optimal localization properties in both spatial and frequency domain. Texture features based on Gabor wavelets transformation are found by the Gabor filtered image. Experiment results indicate the following: (1) the proposed algorithm based on random forest outperformed the-state-of-the-art in pigmented skin lesions detection (2) and the inclusion of Gabor wavelet transformation based texture features improved segmentation accuracy significantly.

  20. Effect of dose reduction on the detection of mammographic lesions: A mathematical observer model analysis

    SciTech Connect

    Chawla, Amarpreet S.; Samei, Ehsan; Saunders, Robert; Abbey, Craig; Delong, David

    2007-08-15

    The effect of reduction in dose levels normally used in mammographic screening procedures on the detection of breast lesions were analyzed. Four types of breast lesions were simulated and inserted into clinically-acquired digital mammograms. Dose reduction by 50% and 75% of the original clinically-relevant exposure levels were simulated by adding corresponding simulated noise into the original mammograms. The mammograms were converted into luminance values corresponding to those displayed on a clinical soft-copy display station and subsequently analyzed by Laguerre-Gauss and Gabor channelized Hotelling observer models for differences in detectability performance with reduction in radiation dose. Performance was measured under a signal known exactly but variable detection task paradigm in terms of receiver operating characteristics (ROC) curves and area under the ROC curves. The results suggested that luminance mapping of digital mammograms affects performance of model observers. Reduction in dose levels by 50% lowered the detectability of masses with borderline statistical significance. Dose reduction did not have a statistically significant effect on detection of microcalcifications. The model results indicate that there is room for optimization of dose level in mammographic screening procedures.

  1. Frequent Detection of Pancreatic Lesions in Asymptomatic High-Risk Individuals

    PubMed Central

    Canto, Marcia Irene; Hruban, Ralph H.; Fishman, Elliot K.; Kamel, Ihab R.; Schulick, Richard; Zhang, Zhe; Topazian, Mark; Takahashi, Naoki; Fletcher, Joel; Petersen, Gloria; Klein, Alison P.; Axilbund, Jennifer; Griffin, Constance; Syngal, Sapna; Saltzman, John R.; Mortele, Koenraad J.; Lee, Jeffrey; Tamm, Eric; Vikram, Raghunandan; Bhosale, Priya; Margolis, Daniel; Farrell, James; Goggins, Michael

    2012-01-01

    BACKGROUND & AIMS The risk of pancreatic cancer is increased in patients with a strong family history of pancreatic cancer or a predisposing germline mutation. Screening can detect curable, non-invasive pancreatic neoplasms, but the optimal imaging approach is not known. We determined the baseline prevalence and characteristics of pancreatic abnormalities using 3 imaging tests to screen asymptomatic, high-risk individuals (HRI). METHODS We screened 225 asymptomatic adult HRI at 5 academic US medical centers once, using computed tomography (CT), magnetic resonance imaging (MRI), and endoscopic ultrasonography (EUS). We compared results in a blinded, independent fashion. RESULTS Ninety-two of 216 HRI (42%) were found to have at least 1 pancreatic mass (84 cystic, 3 solid) or a dilated pancreatic duct (n=5) by any of the imaging modalities. Fifty-one of the 84 HRI with a cyst (60.7%) had multiple lesions, typically small (mean 0.55 cm, range 2–39 mm), in multiple locations. The prevalence of pancreatic lesions increased with age; they were detected in 14% of subjects <50 years old, 34% of subjects 50–59 years old, and 53% of subjects 60–69 years old (P<.0001). CT, MRI, and EUS detected a pancreatic abnormality in 11%, 33.3%, and 42.6% of the HRI, respectively. Among these abnormalities, proven or suspected neoplasms were identified in 85 HRI (82 intraductal papillary mucinous neoplasms [IPMN] and 3 pancreatic endocrine tumors). Three of 5 HRI who underwent pancreatic resection had high-grade dysplasia in <3 cm IPMNs and in multiple intraepithelial neoplasias. CONCLUSIONS Screening of asymptomatic HRI frequently detects small pancreatic cysts, including curable, non-invasive high-grade neoplasms. EUS and MRI detect pancreatic lesions better than CT. PMID:22245846

  2. Impact of JPEG 2000 compression on lesion detection in MR imaging.

    PubMed

    Paz, Juan; Pérez, Marlen; Schelkens, Peter; Rodríguez, José

    2009-11-01

    Lossy compression algorithms enable the efficient transmission of large medical image datasets over bandwidth-limited digital networks or facilitate the long-term storage of the daily image production. Although JPEG 2000 has been adopted by DICOM as the standard for lossy-to-lossless compression, still a set of guidelines needs to be derived that allows for the usage of the lossy mode, potentially jeopardizing the accuracy of lesion detection and characterization, and so, of the resulting diagnosis task effectiveness in the medical diagnosis process. In this article the authors present and evaluate a generic methodology for the determination of the minimal bit rate that still ensures an accurate detection in magnetic resonance images of specific lesions. In this article, they demonstrate the methodology for two particular pathologies, i.e., multiple sclerosis and Virchow-Robin space enlargements. Involving qualified personnel, the minimal bit rate is estimated from ROC experiments initially simulated through mathematical observers that are designed with several objective metrics. The mathematical observer models included three variants of the Hotelling observer plus the non-prewhitening matched filter with eye model, while the objective measures are based on distance, correlation, singular value decomposition, and structural similarity. The results indicate that the highest compression without seriously affecting the detection of the studied lesions is achieved at a bit rate of 0.125 bpp. At this value, the detection effectiveness exceeded 95% with less than 5% standard deviation, while only 4.4% of the outcomes were classified as false negatives by the experts and 11.6% as false positives. The optimal bit rate found assures that important information on the small investigated structures is still preserved for their accurate detection and their a posteriori characterization.

  3. Spontaneous and Dosing Route-related Lung Lesions in Beagle Dogs from Oral Gavage and Inhalation Toxicity Studies: Differentiation from Compound-induced Lesions.

    PubMed

    Mukaratirwa, Sydney; Garcia, Begonya; Isobe, Kaori; Petterino, Claudio; Bradley, Alys

    2016-10-01

    This study was conducted to characterize lung microscopic lesions in control beagle dogs from inhalation and oral gavage toxicity studies, to determine differences associated with the route of administration, and to discuss distinguishing features from compound-induced lung lesions. Samples from 138 control dogs from oral gavage studies and 124 control dogs from inhalation (vehicle control) studies were evaluated microscopically. There was no significant sex-related difference in the incidence of all lesions. Perivascular mononuclear cell infiltration, centriacinar mixed cell infiltration, bronchopneumonia, subpleural septal fibrosis, and alveolar macrophage accumulation were the most common lesions. Aspiration pneumonia was more common in dogs from gavage studies, suggesting reflux after gavage dosing or accidental administration of test formulation as possible causes. Centriacinar mixed cell infiltration was more common in dogs from inhalation studies, suggesting mild irritation by the vehicles used. Vascular lesions, which included pulmonary arteriopathy and smooth muscle mineralization, were observed in a few animals. Some of the spontaneous lesions are similar to lesions induced by test compounds. Compared to spontaneous lesions, compound-induced lesions tend to be multifocal or diffuse, follow a pattern of distribution (e.g., centriacinar, perivascular, and interstitial), show a dose response in the incidence and severity, and may show cell-specific toxicity.

  4. Metal status in human endometrium: Relation to cigarette smoking and histological lesions

    SciTech Connect

    Rzymski, Piotr; Rzymski, Paweł; Tomczyk, Katarzyna; Niedzielski, Przemysław; Jakubowski, Karol; Poniedziałek, Barbara; Opala, Tomasz

    2014-07-15

    Human endometrium is a thick, blood vessel-rich, glandular tissue which undergoes cyclic changes and is potentially sensitive to the various endogenous and exogenous compounds supplied via the hematogenous route. As recently indicated, several metals including Cd, Pb, Cr and Ni represent an emerging class of potential metalloestrogens and can be implicated in alterations of the female reproductive system including endometriosis and cancer. In the present study, we investigated the content of five metals: Cd, Cr, Ni, Pb and Zn in 25 samples of human endometrium collected from Polish females undergoing diagnostic or therapeutic curettage of the uterine cavity. The overall mean metal concentration (analyzed using microwave induced plasma atomic emission spectrometry MIP-OES) decreased in the following order: Cr>Pb>Zn>Ni>Cd. For the first time it was demonstrated that cigarette smoking significantly increases the endometrial content of Cd and Pb. Concentration of these metals was also positively correlated with years of smoking and the number of smoked cigarettes. Tissue samples with recognized histologic lesions (simple hyperplasia, polyposis and atrophy) were characterized by a 2-fold higher Cd level. No relation between the age of the women and metal content was found. Our study shows that human endometrium can be a potential target of metal accumulation within the human body. Quantitative analyses of endometrial metal content could serve as an additional indicator of potential impairments of the menstrual cycle and fertility. - Highlights: • Cd, Cr, Ni, Pb and Zn are detectable in human endometrium. • Mean metal content in human endometrium decreases in Cr>Pb>Zn>Ni>Cd order. • Cigarettes smoking increases endometrial content of Cd and Pb. • Lesioned endometrial tissue was characterized by higher metal contents.

  5. Human immunodeficiency virus (HIV) transcripts identified in HIV-related psoriasis and Kaposi's sarcoma lesions.

    PubMed Central

    Mahoney, S E; Duvic, M; Nickoloff, B J; Minshall, M; Smith, L C; Griffiths, C E; Paddock, S W; Lewis, D E

    1991-01-01

    Persons with HIV infection sometimes develop aggressive psoriasis or Kaposi's sarcoma (KS) not usually seen in other immunosuppressed patients. However, a specific and direct pathophysiological role for HIV-1 in these AIDS-associated disorders remains unclear since HIV has not been easily detected in these skin lesions. By combining in situ hybridization with the sensitive detection technique of confocal laser scanning microscopy, we have demonstrated HIV RNA transcripts in 5 of 15 lesional skin biopsies from HIV-infected psoriasis patients, and in 3 of 8 Kaposi's sarcoma biopsies from HIV-infected patients. HIV transcripts were not detected in normal appearing skin from HIV-infected patients or in psoriatic and normal skin biopsies from uninfected individuals (P = 0.006). Although previous attempts to demonstrate viral sequences in psoriasis and KS lesions have been unsuccessful, in situ hybridization with confocal microscopy has shown the presence of HIV RNA transcripts predominantly within CD4+, Factor XIIIa positive dermal dendrocytes. HIV or cytokines produced by infected cells in skin lesions may therefore play a direct role in the pathogenesis of HIV-associated psoriasis and KS. Images PMID:1676036

  6. Fast approach to evaluate map reconstruction for lesion detection and localization

    SciTech Connect

    Qi, Jinyi; Huesman, Ronald H.

    2004-02-01

    Lesion detection is an important task in emission tomography. Localization ROC (LROC) studies are often used to analyze the lesion detection and localization performance. Most researchers rely on Monte Carlo reconstruction samples to obtain LROC curves, which can be very time-consuming for iterative algorithms. In this paper we develop a fast approach to obtain LROC curves that does not require Monte Carlo reconstructions. We use a channelized Hotelling observer model to search for lesions, and the results can be easily extended to other numerical observers. We theoretically analyzed the mean and covariance of the observer output. Assuming the observer outputs are multivariate Gaussian random variables, an LROC curve can be directly generated by integrating the conditional probability density functions. The high-dimensional integrals are calculated using a Monte Carlo method. The proposed approach is very fast because no iterative reconstruction is involved. Computer simulations show that the results of the proposed method match well with those obtained using the tradition LROC analysis.

  7. Improved detection reveals active β-papillomavirus infection in skin lesions from kidney transplant recipients.

    PubMed

    Borgogna, Cinzia; Lanfredini, Simone; Peretti, Alberto; De Andrea, Marco; Zavattaro, Elisa; Colombo, Enrico; Quaglia, Marco; Boldorini, Renzo; Miglio, Umberto; Doorbar, John; Bavinck, Jan N Bouwes; Quint, Koen D; de Koning, Maurits N C; Landolfo, Santo; Gariglio, Marisa

    2014-08-01

    The aim of this study was to determine whether detection of β-HPV gene products, as defined in epidermodysplasia verruciformis skin cancer, could also be observed in lesions from kidney transplant recipients alongside the viral DNA. A total of 111 samples, corresponding to 79 skin lesions abscised from 17 kidney transplant recipients, have been analyzed. The initial PCR analysis demonstrated that β-HPV-DNA was highly present in our tumor series (85%). Using a combination of antibodies raised against the E4 and L1 proteins of the β-genotypes, we were able to visualize productive infection in 4 out of 19 actinic keratoses, and in the pathological borders of 1 out of 14 squamous cell carcinomas and 1 out of 31 basal cell carcinomas. Increased expression of the cellular proliferation marker minichromosome maintenance protein 7 (MCM7), that extended into the upper epithelial layers, was a common feature of all the E4-positive areas, indicating that cells were driven into the cell cycle in areas of productive viral infections. Although the present study does not directly demonstrate a causal role of these viruses, the detection of E4 and L1 positivity in actinic keratosis and the adjacent pathological epithelium of skin cancer, clearly shows that β-HPV are actively replicating in the intraepidermal precursor lesions of kidney transplant recipients and can therefore cooperate with other carcinogenic agents, such as UVB, favoring skin cancer promotion.

  8. Automatic detection of basal cell carcinoma using telangiectasia analysis in dermoscopy skin lesion images.

    PubMed

    Cheng, Beibei; Erdos, David; Stanley, Ronald J; Stoecker, William V; Calcara, David A; Gómez, David D

    2011-08-01

    Telangiectasia, dilated blood vessels near the surface of the skin of small, varying diameter, are critical dermoscopy structures used in the detection of basal cell carcinoma (BCC). Distinguishing these vessels from other telangiectasia, that are commonly found in sun-damaged skin, is challenging. Image analysis techniques are investigated to find vessels structures in BCC automatically. The primary screen for vessels uses an optimized local color drop technique. A noise filter is developed to eliminate false-positive structures, primarily bubbles, hair, and blotch and ulcer edges. From the telangiectasia mask containing candidate vessel-like structures, shape, size and normalized count features are computed to facilitate the discrimination of benign skin lesions from BCCs with telangiectasia. Experimental results yielded a diagnostic accuracy as high as 96.7% using a neural network classifier for a data set of 59 BCCs and 152 benign lesions for skin lesion discrimination based on features computed from the telangiectasia masks. In current clinical practice, it is possible to find smaller BCCs by dermoscopy than by clinical inspection. Although almost all of these small BCCs have telangiectasia, they can be short and thin. Normalization of lengths and areas helps to detect these smaller BCCs. © 2011 John Wiley & Sons A/S.

  9. Automatic detection of basal cell carcinoma using telangiectasia analysis in dermoscopy skin lesion images

    PubMed Central

    Cheng, Beibei; Erdos, David; Stanley, Ronald J.; Stoecker, William V.; Calcara, David A.; Gómez, David D.

    2011-01-01

    Background Telangiectasia, dilated blood vessels near the surface of the skin of small, varying diameter, are critical dermoscopy structures used in the detection of basal cell carcinoma (BCC). Distinguishing these vessels from other telangiectasia, that are commonly found in sun-damaged skin, is challenging. Methods Image analysis techniques are investigated to find vessels structures found in BCC automatically. The primary screen for vessels uses an optimized local color drop technique. A noise filter is developed to eliminate false-positive structures, primarily bubbles, hair, and blotch and ulcer edges. From the telangiectasia mask containing candidate vessel-like structures, shape, size and normalized count features are computed to facilitate the discrimination of benign skin lesions from BCCs with telangiectasia. Results Experimental results yielded a diagnostic accuracy as high as 96.7% using a neural network classifier for a data set of 59 BCCs and 152 benign lesions for skin lesion discrimination based on features computed from the telangiectasia masks. Conclusion In current clinical practice, it is possible to find smaller BCCs by dermoscopy than by clinical inspection. Although almost all of these small BCCs have telangiectasia, they can be short and thin. Normalization of lengths and areas helps to detect these smaller BCCs. PMID:23815446

  10. Review and management of breast lesions detected with breast tomosynthesis but not visible on mammography and ultrasonography.

    PubMed

    Taskin, Fusun; Durum, Yasemin; Soyder, Aykut; Unsal, Alparslan

    2017-01-01

    Background Breast tomosynthesis is more sensitive than mammography and can detect lesions that are not always visible with conventional methods such as digital mammography (MG) and ultrasonography (US). No standardized approach is available for the management of lesions that are detectable with tomosynthesis but are not visible on MG or US. Purpose To review suspicious breast lesions detected with tomosynthesis but not visible on two-dimensional (2D) MG or US and to determine the management options for these lesions. Material and Methods Ethical committee approval was obtained. The radiological records, biopsy or surgery results, and follow-up findings of 107 patients who had a tomosynthesis-positive but MG- or US-negative breast lesion between 2011 and 2016 were retrospectively evaluated. Results Of 107 lesions visible only with tomosynthesis, 74% were architectural distortions and 26% were asymmetrical opacities. All patients underwent magnetic resonance imaging (MRI) for further evaluation. Among the 48 (45%) MRI-negative lesions, none had a suspicious alteration during the follow-up period. Among the MRI-positive lesions, 28% of the 50 architectural distortions and 11% of the nine asymmetrical opacities were malignant. Conclusion Given the inherent high false-positive rate of breast tomosynthesis, breast MRI prior to biopsy may reduce the number of unnecessary biopsies for suspicious breast lesions that are tomosynthesis-positive only.

  11. αβ T-cell receptors from multiple sclerosis brain lesions show MAIT cell–related features

    PubMed Central

    Held, Kathrin; Bhonsle-Deeng, Latika; Siewert, Katherina; Sato, Wakiro; Beltrán, Eduardo; Schmidt, Stephan; Rühl, Geraldine; Ng, Judy K.M.; Engerer, Peter; Moser, Markus; Klinkert, Wolfgang E.F.; Babbe, Holger; Misgeld, Thomas; Wekerle, Hartmut; Laplaud, David-Axel; Hohlfeld, Reinhard

    2015-01-01

    Objectives: To characterize phenotypes of T cells that accumulated in multiple sclerosis (MS) lesions, to compare the lesional T-cell receptor (TCR) repertoire of T-cell subsets to peripheral blood, and to identify paired α and β chains from single CD8+ T cells from an index patient who we followed for 18 years. Methods: We combined immunohistochemistry, laser microdissection, and single-cell multiplex PCR to characterize T-cell subtypes and identify paired TCRα and TCRβ chains from individual brain-infiltrating T cells in frozen brain sections. The lesional and peripheral TCR repertoires were analyzed by pyrosequencing. Results: We found that a TCR Vβ1+ T-cell population that was strikingly expanded in active brain lesions at clinical onset comprises several subclones expressing distinct yet closely related Vα7.2+ α chains, including a canonical Vα7.2-Jα33 chain of mucosal-associated invariant T (MAIT) cells. Three other α chains bear striking similarities in their antigen-recognizing, hypervariable complementarity determining region 3. Longitudinal repertoire studies revealed that the TCR chains that were massively expanded in brain at onset persisted for several years in blood or CSF but subsequently disappeared except for the canonical Vα7.2+ MAIT cell and a few other TCR sequences that were still detectable in blood after 18 years. Conclusions: Our observation that a massively expanded TCR Vβ1-Jβ2.3 chain paired with distinct yet closely related canonical or atypical MAIT cell–related α chains strongly points to an antigen-driven process in early active MS brain lesions. PMID:25977934

  12. IgG4-related disease presenting with destructive sinonasal lesion mimicking malignancy.

    PubMed

    Chen, Bo-Nien

    2016-11-01

    IgG4-related disease is a newly recognized systemic fibroinflammatory disorder. We report a 36-year-old man who presented with intractable right nasal pain and frontal headache for 1 month. Computed tomography revealed an ill-defined lesion with bony erosion over the right anterior ethmoid sinus and middle turbinate. The lesion was resected through endoscopic anterior ethmoidectomy and middle turbinectomy. IgG4-related disease was definitively diagnosed according to histopathological features. Prednisolone was administered postoperatively. IgG4-related disease presenting with destructive sinonasal lesion mimicking malignancy is rare. Awareness is essential to avoid delayed diagnosis or unnecessary invasive intervention, because the disorder responds to glucocorticoid and immunosuppressant therapy.

  13. Development and validation of a fully automated system for detection and diagnosis of mammographic lesions.

    PubMed

    Casti, Paola; Mencattini, Arianna; Salmeri, Marcello; Ancona, Antonietta; Mangieri, Fabio; Rangayyan, Rangaraj M

    2014-01-01

    We present a comprehensive and fully automated system for computer-aided detection and diagnosis of masses in mammograms. Novel methods for detection include: selection of suspicious focal areas based on analysis of the gradient vector field, rejection of oriented components of breast tissue using multidirectional Gabor filtering, and use of differential features for rejection of false positives (FPs) via clustering of the surrounding fibroglandular tissue. The diagnosis step is based on extraction of contour-independent features for characterization of lesions as benign or malignant from automatically detected circular and annular regions. A new unified 3D free-response receiver operating characteristic framework is introduced for global analysis of two binary categorization problems in cascade. In total, 3,080 suspicious focal areas were extracted from a set of 156 full-field digital mammograms, including 26 malignant tumors, 120 benign lesions, and 18 normal mammograms. The proposed system detected and diagnosed malignant tumors with a sensitivity of 0.96, 0.92, and 0.88 at, respectively, 1.83, 0.46, and 0.45 FPs/image, with two stages of stepwise logistic regression for selection of features, a cascade of Fisher linear discriminant analysis and an artificial neural network with radial basis functions, and leave-one-patient-out cross-validation.

  14. Should we use CT or MRI for detection and characterization of benign adrenal lesions?

    PubMed

    Hrabak-Paar, Maja; Đido, Viktorija; Štern-Padovan, Ranka

    2015-07-01

    Computed tomography (CT) and magnetic resonance imaging (MRI) are the main imaging modalities used for analysis of adrenal lesions. We compared the ability of CT and MRI to detect and characterize benign adrenal lesions. Unenhanced abdominal CT and MRI were performed in 16 patients (age range 39-77), and reviewed by a radiologist with 6years of experience in abdominal imaging. The presence, number, size and structure of each mass were analyzed and compared between the two modalities. There were 18 adrenal masses in 11 patients, four patients had adrenal hyperplasia (AH), whereas one patient had left-sided AH and right-sided adenoma. Ten masses were≥2cm in diameter, and were perfectly depicted using CT and all MRI techniques. There were nine masses with diameter<2cm detected by CT, three of them were missed using MRI. AH was detected in five patients using CT, but its mild form was missed in one patient using MRI. Four masses with attenuation values of>10Hounsfield units could not be characterized using unenhanced CT, but three of them were characterized using MRI. CT has higher sensitivity for detection of small adrenal tumours and adrenal hyperplasia than MRI. MRI is an important tool in characterization of adrenal masses that could not be characterized using unenhanced CT. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  15. Low-contrast lesion detection in tomosynthetic breast imaging using a realistic breast phantom

    NASA Astrophysics Data System (ADS)

    Zhou, Lili; Oldan, Jorge; Fisher, Paul; Gindi, Gene

    2006-03-01

    Tomosynthesis mammography is a potentially valuable technique for detection of breast cancer. In this simulation study, we investigate the efficacy of three different tomographic reconstruction methods, EM, SART and Backprojection, in the context of an especially difficult mammographic detection task. The task is the detection of a very low-contrast mass embedded in very dense fibro-glandular tissue - a clinically useful task for which tomosynthesis may be well suited. The project uses an anatomically realistic 3D digital breast phantom whose normal anatomic variability limits lesion conspicuity. In order to capture anatomical object variability, we generate an ensemble of phantoms, each of which comprises random instances of various breast structures. We construct medium-sized 3D breast phantoms which model random instances of ductal structures, fibrous connective tissue, Cooper's ligaments and power law structural noise for small scale object variability. Random instances of 7-8 mm irregular masses are generated by a 3D random walk algorithm and placed in very dense fibro-glandular tissue. Several other components of the breast phantom are held fixed, i.e. not randomly generated. These include the fixed breast shape and size, nipple structure, fixed lesion location, and a pectoralis muscle. We collect low-dose data using an isocentric tomosynthetic geometry at 11 angles over 50 degrees and add Poisson noise. The data is reconstructed using the three algorithms. Reconstructed slices through the center of the lesion are presented to human observers in a 2AFC (two-alternative-forced-choice) test that measures detectability by computing AUC (area under the ROC curve). The data collected in each simulation includes two sources of variability, that due to the anatomical variability of the phantom and that due to the Poisson data noise. We found that for this difficult task that the AUC value for EM (0.89) was greater than that for SART (0.83) and Backprojection (0.66).

  16. Ex vivo Confocal Imaging with Contrast Agents for the Detection of Oral Potentially Malignant Lesions

    PubMed Central

    Hallani, S. El; Poh, C. F.; Macaulay, C. E.; Follen, M.; Guillaud, M.; Lane, P.

    2013-01-01

    Objectives We investigated the potential use of real-time confocal microscpy in the non-invasive detection of occult oral potentially malignant lesions. Our objectives were to select the best fluorescence contrast agent for cellular morphology enhancement, to build an atlas of confocal microscopic images of normal human oral mucosa, and to determine the accuracy of confocal microscopy to recognise oral high-grade dysplasia lesions on live human tissue. Materials and Methods Five clinically used fluorescent contrast agents were tested in vitro on cultured human cells and validated ex vivo on human oral mucosa. Images acquired ex vivo from normal and diseased human oral biopsies with bench-top fluorescent confocal microscope were compared to conventional histology. Image analyzer software was used as an adjunct tool to objectively compare high-grade dysplasia versus low-grade dysplasia and normal epithelium. Results Acriflavine Hydrochloride provided the best cellular contrast by preferentially staining the nuclei of the epithelium. Using topical application of Acriflavine Hydrochloride followed by confocal microscopy, we could define morphological characteristics of each cellular layer of the normal human oral mucosa, building an atlas of histology-like images. Applying this technique to diseased oral tissue specimen, we were also able to accurately diagnose the presence of high-grade dysplasia through the increased cellularity and changes in nuclear morphological features. Objective measurement of cellular density by quantitative image analysis was a strong discriminant to differentiate between high-grade dysplasia and low-grade dysplasia lesions. Conclusions Pending clinical investigation, real-time confocal microscopy may become a useful adjunct to detect precancerous lesions that are at high risk of cancer progression, direct biopsy and delineate excision margins. PMID:23415144

  17. Effect of monitor display on detection of approximal caries lesions in digital radiographs.

    PubMed

    Isidor, S; Faaborg-Andersen, M; Hintze, H; Kirkevang, L-L; Frydenberg, M; Haiter-Neto, F; Wenzel, A

    2009-12-01

    The aim was to compare the accuracy of five flat panel monitors for detection of approximal caries lesions. Five flat panel monitors, Mermaid Ventura (15 inch, colour flat panel, 1024 x 768, 32 bit, analogue), Olórin VistaLine (19 inch, colour, 1280 x 1024, 32 bit, digital), Samsung SyncMaster 203B (20 inch, colour, 1024 x 768, 32 bit, analogue), Totoku ME251i (21 inch, greyscale, 1400 x 1024, 32 bit, digital) and Eizo FlexScan MX190 (19 inch, colour, 1280 x 1024, 32 bit, digital), were assessed. 160 approximal surfaces of human teeth were examined with a storage phosphor plate system (Digora FMX, Soredex) and assessed by seven observers for the presence of caries lesions. Microscopy of the teeth served as validation for the presence/absence of a lesion. The sensitivities varied between observers (range 7-25%) but the variation between the monitors was not large. The Samsung monitor obtained a significantly higher sensitivity than the Mermaid and Olórin monitors (P<0.02) and a lower specificity than the Eizo and Totoku monitors (P<0.05). There were no significant differences between any other monitors. The percentage of correct scores was highest for the Eizo monitor and significantly higher than for the Mermaid and Olórin monitors (P<0.03). There was no clear relationship between the diagnostic accuracy and the resolution or price of the monitor. The Eizo monitor was associated with the overall highest percentage of correct scores. The standard analogue flat panel monitor, Samsung, had higher sensitivity and lower specificity than some of the other monitors, but did not differ in overall accuracy for detection of carious lesions.

  18. Concordance of human papillomavirus types detected on the surface and in the tissue of genital lesions in men.

    PubMed

    Anic, Gabriella M; Messina, Jane L; Stoler, Mark H; Rollison, Dana E; Stockwell, Heather; Villa, Luisa L; Lazcano-Ponce, Eduardo; Gage, Christine; Silva, Roberto Jose C; Baggio, Maria L; Salmerón, Jorge; Giuliano, Anna R

    2013-09-01

    Swabbing the surface of a genital lesion to obtain a sample for HPV DNA testing is less invasive than a biopsy, but may not represent HPV types present in the lesion tissue. The objective of this study was to examine the concordance of HPV types detected in swab and biopsy samples from 165 genital lesions from men ages 18-70. Lesions included 90 condyloma, 10 penile intraepithelial neoplasia (PeIN), 23 non-condyloma with a known histology, and 42 lesions with an undetermined histology. All lesions were sampled by swabbing the surface of the lesion with a pre-wetted Dacron swab and taking a shave biopsy. HPV genotyping was performed using Linear Array for swab samples and INNO-LiPA for biopsy samples. The kappa and McNemar statistics were used to compare the concordance of detecting HPV types in swab and biopsy samples. Both sampling methods had high agreement for detection of HPV DNA in condyloma (87.8% agreement) and PeIN (100% agreement). There was also high concordance for detection of HPV16 (kappa = 1.00) and HPV18 (kappa = 1.00) in PeIN, however, agreement was low to moderate for detecting HPV6 (kappa = 0.31) and HPV11 (kappa = 0.56) in condyloma. Low to moderate agreement was also observed between sampling methods for detecting individual HPV types in the non-condyloma and lesions with an indefinite histology. The results suggest that obtaining a biopsy in addition to swabbing the surface of a lesion may provide additional information about specific HVP types associated with male genital lesions. Copyright © 2013 Wiley Periodicals, Inc.

  19. Concordance of human papillomavirus types detected on the surface and in the tissue of genital lesions in men

    PubMed Central

    Anic, Gabriella M.; Messina, Jane L.; Stoler, Mark H.; Rollison, Dana E.; Stockwell, Heather; Villa, Luisa L.; Lazcano-Ponce, Eduardo; Gage, Christine; Silva, Roberto Jose C.; Baggio, Maria L.; Salmerón, Jorge; Giuliano, Anna R.

    2013-01-01

    Summary Swabbing the surface of a genital lesion to obtain a sample for HPV DNA testing is less invasive than a biopsy, but may not represent HPV types present in the lesion tissue. The objective of this study was to examine the concordance of HPV types detected in swab and biopsy samples from 165 genital lesions from men ages 18-70. Lesions included 90 condyloma, 10 penile intraepithelial neoplasia (PeIN), 23 non-condyloma with a known histology, and 42 lesions with an undetermined histology. All lesions were sampled by swabbing the surface of the lesion with a pre-wetted Dacron swab and taking a shave biopsy. HPV genotyping was performed using Linear Array for swab samples and INNO-LiPA for biopsy samples. The kappa and McNemar statistics were used to compare the concordance of detecting HPV types in swab and biopsy samples. Both sampling methods had high agreement for detection of HPV DNA in condyloma (87.8% agreement) and PeIN (100% agreement). There was also high concordance for detection of HPV16 (kappa = 1.00) and HPV18 (kappa = 1.00) in PeIN, however, agreement was low to moderate for detecting HPV6 (kappa = 0.31) and HPV11 (kappa = 0.56) in condyloma. Low to moderate agreement was also observed between sampling methods for detecting individual HPV types in the non-condyloma and lesions with an indefinite histology. The results suggest that obtaining a biopsy in addition to swabbing the surface of a lesion may provide additional information about specific HVP types associated with male genital lesions. PMID:23852680

  20. Time-resolved optical mammography between 637 and 985 nm: clinical study on the detection and identification of breast lesions

    NASA Astrophysics Data System (ADS)

    Taroni, Paola; Torricelli, Alessandro; Spinelli, Lorenzo; Pifferi, Antonio; Arpaia, Francesco; Danesini, Gianmaria; Cubeddu, Rinaldo

    2005-06-01

    The first time-resolved optical mammograph operating beyond 900 nm was tested in a retrospective clinical study involving 194 patients with malignant and benign lesions, to investigate the diagnostic potential for the detection and characterization of breast lesions. For the first part of the study (101 patients with 114 lesions), the system was operated at 683, 785, 913 and 975 nm. Subsequently, to improve the spectral content of optical images, the number of wavelengths was increased (up to 7) and the spectral range was extended (637-985 nm). Late gated intensity and scattering images provide sensitivity to tissue composition (oxy- and deoxyhaemoglobin, water and lipids) and physiology (total haemoglobin content and oxygen saturation), as well as to structural changes. Tumours are typically identified because of the strong blood absorption at short wavelengths (637-685 nm), while cysts are characterized by low scattering, leading to a detection rate of approximately 80% for both lesion types, when detection is required in both cranio-caudal and oblique views. The detection rate for other benign lesions, such as fibroadenomas, is presently much lower (<40%). The effectiveness of the technique in localizing and identifying different lesion types was analysed as a function of various parameters (lesion size, compressed breast thickness, age, body mass index, breast parenchymal pattern). The possibility that physiologic changes due to the development of a malignant lesion could affect the entire breast was investigated. The capacity to assess the density of breast based on the average scattering properties was also tested.

  1. Investigation of relations between skin cancer lesions' images and their fluorescent spectra

    NASA Astrophysics Data System (ADS)

    Pavlova, P.; Borisova, E.; Avramov, L.; Petkova, El.; Troyanova, P.

    2010-03-01

    This investigation is based on images obtained from healthy tissue and skin cancer lesions and their fluorescent spectra of cutaneous lesions derived after optical stimulation. Our analyses show that the lesions’ spectra of are different of those, obtained from normal tissue and the differences depend on the type of cancer. We use a comparison between these “healthy” and “unhealthy” spectra to define forms of variations and corresponding diseases. However, the value of the emitted light varies not only between the patients, but also depending on the position of the tested area inside of one lesion. These variations could be result from two reasons: different degree of damaging and different thickness of the suspicious lesion area. Regarded to the visible image of the lesion, it could be connected with the chroma of colour of the tested area and the lesion homogeneity that corresponds to particular disease. For our investigation, images and spectra of three non-melanoma cutanous malignant tumors are investigated, namely—basal cell carcinoma, squamous cell carcinoma, and keratoacanthoma. The images were processed obtaining the chroma by elimination of the background—healthy tissue, and applying it as a basic signal for transformation from RGB to Lab colorimetric model. The chroma of the areas of emission is compared with the relative value of fluorescence spectra. Specific spectral features are used to develop hybrid diagnostic algorithm (including image and spectral features) for differentiation of these three kinds of malignant cutaneous pathologies.

  2. Concurrent criterion-related validity of physical examination tests for hip labral lesions: a systematic review.

    PubMed

    Leibold, M Rebecca; Huijbregts, Peter A; Jensen, Richard

    2008-01-01

    Hip injuries are prevalent, especially within the athletic population. Of the hip injuries in this population, some 18-55% are lesions to the labrum of the hip. Clinical diagnosis of hip labral lesions is difficult because data on prevalence are varied. In addition, data on the prevalence of internal and external risk factors are absent as are data on the correlation of these risk factors with labral lesions, making it difficult to gauge the diagnostic utility. The mechanism of injury is often unknown or not specific to labral lesions. Internal risk factors may remain hidden to physical therapists because in most jurisdictions, ordering imaging tests is not within their scope of practice. Anterior inguinal pain seems highly sensitive for the diagnosis of patients with labral lesions but can hardly be considered specific; data on other pain-related and mechanical symptoms clearly have little diagnostic utility, making these data collected during the patient history almost irrelevant to diagnosis. By way of a comprehensive literature review and narrative and systematic analysis of the methodological quality of the retrieved diagnostic utility studies, this paper aimed to determine a diagnostic physical examination test or test cluster based on current best evidence for the diagnosis of hip labral lesions. Current best evidence indicates that a negative finding for the flexion-adduction-internal rotation test, the flexion-internal rotation test, the impingement provocation test, the flexion-adduction-axial compression test, the Fitzgerald test, or a combination of these tests provides the clinician with the greatest evidence-based confidence that a hip labral lesion is absent. Currently, research has produced no tests with sufficient specificity to help confidently rule in a diagnosis of hip labral lesion. Suggestions for future research are provided.

  3. Oral lichenoid lesions related to contact with dental materials: a literature review.

    PubMed

    Cobos-Fuentes, María-José; Martínez-Sahuquillo-Márquez, Angel; Gallardo-Castillo, Isabel; Armas-Padrón, Jose-Ramón; Moreno-Fernández, Ana; Bullón-Fernández, Pedro

    2009-10-01

    Oral lichenoid lesions related to contact are defined as oral-cavity eruptions with an identifiable etiology, and are clinically and histologically similar to oral lichen planus. Within this group are found oral lichenoid lesions related to contact with dental materials (OLLC), the most common being those related to silver amalgam. Currently, it remains difficult to diagnose these lesions due to the clinical and histopathological similarity with oral lichen planus and other oral mucosa lesions of lichenoid characteristics. In the present paper, we carry out an updated review of the tests for, and the different characteristics of OLLC, which may aid the diagnosis. For this review, we made searches in the Pubmed(R) and Cochrane(R) databases. Among the literature we found several published papers, from which we have used review papers, case papers, cohort studies, case and control studies, and a meta-analysis study. After carrying out this review, we can conclude that the diagnosis of these lesions is still difficult and controversial. However, there are different aspects in the clinical presentation, pathological study and results obtained when replacing suspect materials, which, when taken together, may be useful when establishing the final diagnosis of OLLC.

  4. Heterogeneity of Multiple Sclerosis White Matter Lesions Detected With T2*-Weighted Imaging at 7.0 Tesla.

    PubMed

    Yao, Bing; Ikonomidou, Vasiliki N; Cantor, Fredric K; Ohayon, Joan M; Duyn, Jeff; Bagnato, Francesca

    2015-01-01

    Postmortem studies in multiple sclerosis (MS) indicate that in some white matter lesions (WM-Ls), iron is detectable with T2*-weighted (T2*-w), and its reciprocal R2* relaxation rate, magnetic resonance imaging (MRI) at 7.0 Tesla (7T). This iron appears as a hyperintense rim in R2* images surrounding a hypointense core. We describe how this observation relates to clinical/radiological characteristics of patients, in vivo. We imaged 16 MS patients using 3T and 7T scanners. WM-Ls were identified on T1-w / T2-w 3T-MRIs. Thereafter, WM-Ls with a rim of elevated R2* at 7T were counted and compared to their appearance on conventional MRIs. We counted 36 WM-Ls presenting a rim of elevated R2* in 10 patients. Twenty-three (64%) lesions coincided with focal WM-Ls on T2-w MRIs; 13 (36%) coincided with only portions of larger lesions on T2-w images; and 20 (56%) corresponded to a hypointense chronic black hole. WM-Ls presenting a rim of elevated R2* were seen in both relapsing-remitting patients with low disability and in those with long-standing secondary progressive MS. WM-Ls with a contour of high R2* are present at different MS stages, potentially representing differences in the contribution of iron in MS disease evolution. Copyright © 2015 by the American Society of Neuroimaging.

  5. Detection of circulating pancreas epithelial cells in patients with pancreatic cystic lesions.

    PubMed

    Rhim, Andrew D; Thege, Fredrik I; Santana, Steven M; Lannin, Timothy B; Saha, Trisha N; Tsai, Shannon; Maggs, Lara R; Kochman, Michael L; Ginsberg, Gregory G; Lieb, John G; Chandrasekhara, Vinay; Drebin, Jeffrey A; Ahmad, Nuzhat; Yang, Yu-Xiao; Kirby, Brian J; Stanger, Ben Z

    2014-03-01

    Hematogenous dissemination is thought to be a late event in cancer progression. We recently showed in a genetic model of pancreatic ductal adenocarcinoma that pancreas cells can be detected in the bloodstream before tumor formation. To confirm these findings in humans, we used microfluidic geometrically enhanced differential immunocapture to detect circulating pancreas epithelial cells in patient blood samples. We captured more than 3 circulating pancreas epithelial cells/mL in 7 of 21 (33%) patients with cystic lesions and no clinical diagnosis of cancer (Sendai criteria negative), 8 of 11 (73%) with pancreatic ductal adenocarcinoma, and in 0 of 19 patients without cysts or cancer (controls). These findings indicate that cancer cells are present in the circulation of patients before tumors are detected, which might be used in risk assessment.

  6. Flat neoplastic lesions of the colon and rectum detected by high-resolution video endoscopy and chromoscopy.

    PubMed

    Jaramillo, E; Watanabe, M; Slezak, P; Rubio, C

    1995-08-01

    Because small flat colorectal neoplastic lesions (i.e., flat adenomas and flat adenocarcinomas) may be as translucent as the surrounding mucosa, they can remain undetected at conventional endoscopy. By combining high-resolution video endoscopy and chromoscopy, we detected 109 colorectal flat neoplastic lesions in 55 of 232 patients studied. Forty-three (78%) of the 55 patients with flat neoplastic lesions were over 60 years of age. No flat neoplastic lesions were seen in patients under 40 years of age. Flat neoplastic lesions were more frequent in men (35%) than in women (15%). Seventy-seven (71%) of the 109 flat neoplastic lesions measured 0.5 cm or less, 23 (21%) between 0.6 and 1.0 cm, and 9 (8%) more than 1.0 cm. Low-grade dysplasia and high-grade dysplasia were found in 94 (86%) and 13 (12%) of the flat neoplastic lesions, respectively. Adenocarcinoma was diagnosed in 3 (3%) flat lesions: 1 (1%) carcinoma originating in a flat adenoma and 2 (2%) adenocarcinomas without recognizable adenomatous elements. No adenocarcinomas were seen in lesions measuring 1.0 cm or less. Fourteen flat neoplastic lesions had a central depression at endoscopy. Flat neoplastic lesions with central depression more frequently showed high-grade dysplasia (43%) than did flat neoplastic lesions without central depression (7%). Central depression in flat neoplastic lesions should be considered a possible endoscopic marker for severe dysplasia. Our results suggest that flat neoplastic lesions occur more frequently than previously reported in Scandinavia. Flat adenomas may play an important role in the histogenesis of colorectal cancer.

  7. A phantom design and assessment of lesion detectability in PET imaging

    NASA Astrophysics Data System (ADS)

    Wollenweber, Scott D.; Kinahan, Paul E.; Alessio, Adam M.

    2017-03-01

    The early detection of abnormal regions with increased tracer uptake in positron emission tomography (PET) is a key driver of imaging system design and optimization as well as choice of imaging protocols. Detectability, however, remains difficult to assess due to the need for realistic objects mimicking the clinical scene, multiple lesion-present and lesion-absent images and multiple observers. Fillable phantoms, with tradeoffs between complexity and utility, provide a means to quantitatively test and compare imaging systems under truth-known conditions. These phantoms, however, often focus on quantification rather than detectability. This work presents extensions to a novel phantom design and analysis techniques to evaluate detectability in the context of realistic, non-piecewise constant backgrounds. The design consists of a phantom filled with small solid plastic balls and a radionuclide solution to mimic heterogeneous background uptake. A set of 3D-printed regular dodecahedral `features' were included at user-defined locations within the phantom to create `holes' within the matrix of chaotically-packed balls. These features fill at approximately 3:1 contrast to the lumpy background. A series of signal-known-present (SP) and signal-known-absent (SA) sub-images were generated and used as input for observer studies. This design was imaged in a head-like 20 cm diameter, 20 cm long cylinder and in a body-like 36 cm wide by 21 cm tall by 40 cm long tank. A series of model observer detectability indices were compared across scan conditions (count levels, number of scan replicates), PET image reconstruction methods (with/without TOF and PSF) and between PET/CT scanner system designs using the same phantom imaged on multiple systems. The detectability index was further compared to the noise-equivalent count (NEC) level to characterize the relationship between NEC and observer SNR.

  8. Computer-assisted lesion detection system for stomach screening using stomach shape and appearance models

    NASA Astrophysics Data System (ADS)

    Midoh, Y.; Nakamura, M.; Takashima, M.; Nakamae, K.; Fujioka, H.

    2007-03-01

    In Japan, stomach cancer is one of the three most common causes of death from cancer. Since periodic health checks of stomach X-rays have become more widely carried out, the physicians' burdens have been increasing in the mass screening to detect initial symptoms of a disease. For the purpose of automatic diagnosis, we try to develop a computer-assisted lesion detection system for stomach screening. The proposed system has two databases. One is the stomach shape database that consists of the computer graphics stomach 3D models based on biomechanics simulation and their projected 2D images. The other is the normal appearance database that is constructed by learning patterns in a normal patient training set. The stomach contour is extracted from an X-ray image including a barium filled region by the following steps. Firstly, the approximated stomach region is obtained by nonrigid registration based on mutual information. We define nonrigid transformation as one that includes translations, rotations, scaling, air-barium interface and weights of eigenvectors determined by principal components analysis in the stomach shape database. Secondly, the accurate stomach contour is extracted from the gradient of an image by using the Dynamic Programming. After then, stomach lesions are detected by inspecting whether the Mahalanobis distance from the mean in the normal appearance database is longer than a suitable value on the extracted stomach contour. We applied our system to 75 X-ray images of barium-filled stomach to show its validity.

  9. [Correlation of hybrid II capture cytologic exam in diagnosis of cervical lesions related to HPV].

    PubMed

    Saturnino, Ana Conceição Ribeiro Dantas; Diniz, Veruska Cassandra; Sisenando, Herbert Ary Arzabe Anteza Costa Nóbrega; de Souza, Eroisa Maria Conceição Oliveira; de Paiva, Magnus Sérgio Martins; de Brito, Maria Helena Marques Fonseca; Ramos, Eleni Souto Nóbrega

    2005-01-01

    The aim of the present study was confront the results of the cytological examination with hybrid capture II in the diagnosis of induced cervical intraepithelial lesion-HPV, correlating the cytological findings with biomoleculares. The research was carried through in a group of 160 sexually active women who had espontaneamente looked its gynecologists for consultation of routine, having been submitted to the collection of cervicovaginal material for cytology and for examination of hybrid capture II in the Centro de Patologia Clínica and the Hospital e Maternidade Promater, in the city of the Natal-RN. The results had shown to relatively high numbers of positive cases for HPV using hybrid capture II (41.87%) and the cytology (23.75%). The agreement between the two studied methods relatively was raised (59.38%). It was evident also that the viruses with high oncogênico potential had presented found in the compatible cytology with Lesion of low risk (11.88%), followed of Lesion of high risk (NIC II and III); already the viruses with low oncogênico potential were more associates the Lesion of low risk (6.25%), followed of Lesion of high risk. The cytology, exactly with its limitations, is an important method in the detention of attributable patologias to the HPV, emphasizing that the molecular method comes to complement it and to consolidate the cytological findings.

  10. Spontaneous Age-related Lesions of the Kidney Fornices in Sprague-Dawley Rats.

    PubMed

    Tomonari, Yuki; Kurotaki, Tetsuro; Sato, Junko; Doi, Takuya; Kokoshima, Hiroko; Kanno, Takeshi; Tsuchitani, Minoru; Seely, John Curtis

    2016-02-01

    The upper portion of the rat kidney pelvis has specialized anatomic structures referred to as fornices. Fornices have a role in urine concentration. Spontaneous lesions including mineralization, epithelial hyperplasia, and inflammatory cell infiltration may occur in the area of the fornices. However, little information regarding specific historical control data or the spontaneous development of these findings in male and female fornices is known. Understanding spontaneous age-related lesions in the area of the fornices versus other portions of the kidney pelvis may be relevant in the identification of test article-induced changes. A retrospective study was conducted of male and female Sprague-Dawley rat kidney fornices over several time points to determine the incidence and severity of mineralization, epithelial hyperplasia, and inflammatory cell infiltration. Based on this investigation, these lesions appeared to increase over time and, in general, occurred earlier and with a greater incidence in females. Regarding those chemicals that may result in lesions of the kidney pelvis, it may be important for pathologists to separately diagnose lesions of the fornices from other portions of the kidney pelvis to help differentiate between any spontaneous age-related and induced changes.

  11. Expression of Epidermal c-Kit+ of Vitiligo Lesions Is Related to Responses to Excimer Laser

    PubMed Central

    Park, Oun Jae; Han, Ji Su; Lee, Sang Hyung; Park, Chan-Sik; Won, Chong Hyun; Lee, Mi Woo; Choi, Jee Ho

    2016-01-01

    Background The survival and growth of melanocytes are controlled by the binding of stem cell factor to its cell surface receptor c-kit+ (CD117). We have observed that c-kit+ melanocytes existed in some lesions of vitiligo, while Melan A+ cells were absent. Objective To verify possible relation between c-kit+ expression and treatment response in non-segmental vitiligo lesions Methods Skin biopsies were done from the center of the 47 lesions from the 47 patients with non-segmental vitiligo. Expression of c-kit+ and Melan A, and amounts of melanin in the epidermis were assessed in each lesion, and treatment responses to excimer laser were evaluated. Results Thirty-five of the 47 lesions (74.5%) had c-kit+ phenotypes. There was significant difference of c-kit staining value between good responders in 3 months of excimer laser treatment (average of 24 sessions) and the others. Conclusion c-Kit expression in vitiliginous epidermis may be related to better treatment responses to excimer laser. PMID:27489428

  12. High throughput image cytometry for detection of suspicious lesions in the oral cavity

    NASA Astrophysics Data System (ADS)

    MacAulay, Calum; Poh, Catherine F.; Guillaud, Martial; Michele Williams, Pamela; Laronde, Denise M.; Zhang, Lewei; Rosin, Miriam P.

    2012-08-01

    The successful management of oral cancer depends upon early detection, which relies heavily on the clinician's ability to discriminate sometimes subtle alterations of the infrequent premalignant lesions from the more common reactive and inflammatory conditions in the oral mucosa. Even among experienced oral specialists this can be challenging, particularly when using new wide field-of-view direct fluorescence visualization devices clinically introduced for the recognition of at-risk tissue. The objective of this study is to examine if quantitative cytometric analysis of oral brushing samples could facilitate the assessment of the risk of visually ambiguous lesions. About 369 cytological samples were collected and analyzed: (1) 148 samples from pathology-proven sites of SCC, carcinoma in situ or severe dysplasia; (2) 77 samples from sites with inflammation, infection, or trauma, and (3) 144 samples from normal sites. These were randomly separated into training and test sets. The best algorithm correctly recognized 92.5% of the normal samples, 89.4% of the abnormal samples, 86.2% of the confounders in the training set as well as 100% of the normal samples, and 94.4% of the abnormal samples in the test set. These data suggest that quantitative cytology could reduce by more than 85% the number of visually suspect lesions requiring further assessment by biopsy.

  13. Method to improve cancerous lesion detection sensitivity in a dedicated dual-head scintimammography system

    DOEpatents

    Kieper, Douglas Arthur [Newport News, VA; Majewski, Stanislaw [Yorktown, VA; Welch, Benjamin L [Hampton, VA

    2008-10-28

    An improved method for enhancing the contrast between background and lesion areas of a breast undergoing dual-head scintimammographic examination comprising: 1) acquiring a pair of digital images from a pair of small FOV or mini gamma cameras compressing the breast under examination from opposing sides; 2) inverting one of the pair of images to align or co-register with the other of the images to obtain co-registered pixel values; 3) normalizing the pair of images pixel-by-pixel by dividing pixel values from each of the two acquired images and the co-registered image by the average count per pixel in the entire breast area of the corresponding detector; and 4) multiplying the number of counts in each pixel by the value obtained in step 3 to produce a normalization enhanced two dimensional contrast map. This enhanced (increased contrast) contrast map enhances the visibility of minor local increases (uptakes) of activity over the background and therefore improves lesion detection sensitivity, especially of small lesions.

  14. Method to improve cancerous lesion detection sensitivity in a dedicated dual-head scintimammography system

    DOEpatents

    Kieper, Douglas Arthur [Seattle, WA; Majewski, Stanislaw [Morgantown, WV; Welch, Benjamin L [Hampton, VA

    2012-07-03

    An improved method for enhancing the contrast between background and lesion areas of a breast undergoing dual-head scintimammographic examination comprising: 1) acquiring a pair of digital images from a pair of small FOV or mini gamma cameras compressing the breast under examination from opposing sides; 2) inverting one of the pair of images to align or co-register with the other of the images to obtain co-registered pixel values; 3) normalizing the pair of images pixel-by-pixel by dividing pixel values from each of the two acquired images and the co-registered image by the average count per pixel in the entire breast area of the corresponding detector; and 4) multiplying the number of counts in each pixel by the value obtained in step 3 to produce a normalization enhanced two dimensional contrast map. This enhanced (increased contrast) contrast map enhances the visibility of minor local increases (uptakes) of activity over the background and therefore improves lesion detection sensitivity, especially of small lesions.

  15. Method to improve cancerous lesion detection sensitivity in a dedicated dual-head scintimammography system

    DOEpatents

    Kieper, Douglas Arthur; Majewski, Stanislaw; Welch, Benjamin L.

    2012-07-03

    An improved method for enhancing the contrast between background and lesion areas of a breast undergoing dual-head scintimammographic examination comprising: 1) acquiring a pair of digital images from a pair of small FOV or mini gamma cameras compressing the breast under examination from opposing sides; 2) inverting one of the pair of images to align or co-register with the other of the images to obtain co-registered pixel values; 3) normalizing the pair of images pixel-by-pixel by dividing pixel values from each of the two acquired images and the co-registered image by the average count per pixel in the entire breast area of the corresponding detector; and 4) multiplying the number of counts in each pixel by the value obtained in step 3 to produce a normalization enhanced two dimensional contrast map. This enhanced (increased contrast) contrast map enhances the visibility of minor local increases (uptakes) of activity over the background and therefore improves lesion detection sensitivity, especially of small lesions.

  16. Light diffuse reflectance for detection and differentiation of teeth caries lesions

    NASA Astrophysics Data System (ADS)

    Borisova, E.; Uzunov, Tz.; Valkanov, S.; Avramov, L.

    2007-05-01

    One of the goals of the contemporary dentistry is differentiation between carious stages that must be fast, non-invasive procedure, which will allow to the dentists to make reliable judgments. One suitable candidate for such method is reflectance spectroscopy. The objectives of current study are to determine the feasibility of applying the light reflectance spectroscopy technique for detection of different carious stages; therefore reflectance spectra of teeth illuminated at 450- 900 nm light were recorded. There are obtained reflectance signals from the healthy enamel, dentine and different lesion stages of the investigated teeth. These spectra are compared to that, obtained by non-carious tooth lesions - fluorosa and odontolithiasis, resembling on initial carious stages. There is observed a significant decrease of the intensity of the reflected light in blue region in the case of caries. Reflectance signals, obtained from non-carious lesions also have significantly different character and could be used for differentiation between them and initial carious stages. An algorithm for differentiation between carious stages is proposed with diagnostic accuracy achieved up to 86,1% between precarious stage and sound tooth and 100% for determination of deep cavitation. Some comments about role of teeth enamel structure and anisotropy factor of dental layers on the results obtained are also made.

  17. Retinal image analysis to detect and quantify lesions associated with diabetic retinopathy.

    PubMed

    Sánchez, C I; Hornero, R; López, M I; Poza, J

    2004-01-01

    An automatic method to detect hard exudates, a lesion associated with diabetic retinopathy, is proposed. The algorithm found on their color, using a statistical classification, and their sharp edges, applying an edge detector, to localize them. A sensitivity of 79.62% with a mean number of 3 false positives per image is obtained in a database of 20 retinal image with variable color, brightness and quality. In that way, we evaluate the robustness of the method in order to make adequate to a clinical environment. Further efforts will be done to improve its performance.

  18. Experimental evaluation of a simple lesion detection task with Time-of-Flight PET

    NASA Astrophysics Data System (ADS)

    Surti, S.; Karp, J. S.

    2009-02-01

    Parts (a) and (b) of figure 8 in this article were in error not included in the published article. The correct figure is reproduced below. figure 8 Figure 8. Plots of CRC (a) and (b) and Noise (c) and (d) as a function of iteration number for varying scan times in the 35 cm lesion detectability phantom. Left column (a and c) shows result from TOF reconstructions while the right column (b) and (d) has the non-TOF reconstruction results. The curves within each plot are for varying scan times of 2 (circle), 3 (dtri), 4 ◊, and 5 minutes squ.

  19. Radiographic detection of thoracic lesions in adult cows: A retrospective study of 42 cases (1995–2002)

    PubMed Central

    Masseau, Isabelle; Fecteau, Gilles; Breton, Luc; Hélie, Pierre; Beauregard, Guy; Blond, Laurent

    2008-01-01

    Medical records of 42 cows that underwent both thoracic radiographic and postmortem examinations within a period of 7 days were reviewed to develop an evaluation grid to interpret bovine thoracic radiographs and to determine the sensitivity and the specificity of thoracic radiographs for detection of thoracic lesions, based on postmortem examination. Most cows (64%) had clinical signs of respiratory disease, whereas 19% showed signs of cardiac problems. The sensitivity and specificity of radiographs for identifying cows with thoracic lesions were 94% and 50%, respectively. In this study, with a prevalence of thoracic lesions of 86%, the positive- and negative-predictive values were 92% and 57%, respectively. This study provides an evaluation grid that allows standardization of the reading of bovine thoracic radiographs and the identification of most thoracic lesions. Bovine thoracic radiographs are useful in detecting thoracic lesions in cows. PMID:18390098

  20. Automatic detection and segmentation of liver metastatic lesions on serial CT examinations

    NASA Astrophysics Data System (ADS)

    Ben Cohen, Avi; Diamant, Idit; Klang, Eyal; Amitai, Michal; Greenspan, Hayit

    2014-03-01

    In this paper we present a fully automated method for detection and segmentation of liver metastases on serial CT examinations (portal phase) given a 2D baseline segmentation mask. Our database contains 27 CT scans, baselines and follow-ups, of 12 patients and includes 22 test cases. Our method is based on the information given in the baseline CT scan which contains the lesion's segmentation mask marked manually by a radiologist. We use the 2D baseline segmentation mask to identify the lesion location in the follow-up CT scan using non-rigid image registration. The baseline CT scan is also used to locate regions of tissues surrounding the lesion and to map them onto the follow-up CT scan, in order to reduce the search area on the follow-up CT scan. Adaptive region-growing and mean-shift segmentation are used to obtain the final lesion segmentation. The segmentation results are compared to those obtained by a human radiologist. Compared to the reference standard our method made a correct RECIST 1.1 assessment for 21 out of 22 test cases. The average Dice index was 0.83 +/- 0.07, average Hausdorff distance was 7.85+/- 4.84 mm, average sensitivity was 0.87 +/- 0.11 and positive predictive value was 0.81 +/- 0.10. The segmentation performance and the RECIST assessment results look promising. We are pursuing the methodology further with expansion to 3D segmentation while increasing the dataset we are collecting from the CT abdomen unit at Sheba medical center.

  1. Focal cortical lesion detection in multiple sclerosis: 3 Tesla DIR versus 7 Tesla FLASH-T2.

    PubMed

    Nielsen, A Scott; Kinkel, R Philip; Tinelli, Emanuele; Benner, Thomas; Cohen-Adad, Julien; Mainero, Caterina

    2012-03-01

    To evaluate the inter-rater agreement of cortical lesion detection using 7 Tesla (T) FLASH-T2 and 3T DIR sequences. Twenty-six patients with multiple sclerosis were scanned on a human 7T (Siemens) and 3T MRI (TIM Trio, Siemens) to acquire 3T DIR/MEMPR and 7T FLASH-T2 sequences. Four independent reviewers scored and categorized cortical lesions in the bilateral precentral gyri (motor strips) as leukocortical, intracortical, or subpial. Inter-rater agreement was assessed according to lesion category using the kappa statistic. The sensitivity of recent MAGNIMS consensus guidelines for cortical lesion detection using 3T DIR was assessed with 7T FLASH-T2 as the reference gold standard. Inter-rater agreement at 7T was excellent compared with 3T (k = 0.97 versus 0.12). FLASH-T2 at 7T detected subpial lesions while 3T DIR did not. The predicted sensitivity of 3T DIR sequence for cortical lesions in vivo is modest (range of 13.6 to 18.3%). The 7T FLASH-T2 detects more cortical-particularly subpial-lesions compared with 3T DIR. In the absence of DIR/postmortem data, 7T FLASH-T2 is a suitable gold-standard instrument and should be incorporated into future consensus guidelines. Copyright © 2011 Wiley-Liss, Inc.

  2. Bias, underestimation of risk, and loss of statistical power in patient-level analyses of lesion detection.

    PubMed

    Obuchowski, Nancy A; Mazzone, Peter J; Dachman, Abraham H

    2010-03-01

    Sensitivity and the false positive rate are usually defined with the patient as the unit of observation, i.e., the diagnostic test detects or does not detect disease in a patient. For tests designed to find and diagnose lesions, e.g., lung nodules, the usual definitions of sensitivity and specificity may be misleading. In this paper we describe and compare five measures of accuracy of lesion detection. The five levels of evaluation considered were patient level without localization, patient level with localization, region of interest (ROI) level without localization, ROI level with localization, and lesion level. We found that estimators of sensitivity that do not require the reader to correctly locate the lesion overstate sensitivity. Patient-level estimators of sensitivity can be misleading when there is more than one lesion per patient and they reduce study power. Patient-level estimators of the false positive rate can conceal important differences between techniques. Referring clinicians rely on a test's reported accuracy to both choose the appropriate test and plan management for their patients. If reported sensitivity is overstated, the clinician could choose the test for disease screening, and have false confidence that a negative test represents the true absence of lesions. Similarly, the lower false positive rate associated with patient-level estimators can mislead clinicians about the diagnostic value of the test and consequently that a positive finding is real. We present clear recommendations for studies assessing and comparing the accuracy of tests tasked with the detection and interpretation of lesions...

  3. Clinical evaluation of an enhanced white light and fluorescence device for early detection of caries lesions.

    PubMed

    Amaechi, B T; Chedjieu, I; Lozano-Pineda, Juanita

    2013-01-01

    Sensitivity of a device based on Fluorescence Imaging with Reflectance Enhancement (FIRE) in detecting a potential incipient lesion (PIL) was compared with visual examination to demonstrate non-inferiority to it. Visual examination (VE) and an investigational device (ID) were used to detect PIL (actual incipient caries [AIC] and hypomineralization). Seventeen subjects satisfied data analysis criteria. Two-hundred and seventy-seven AIC and 367 hypomineralizations reached VE consensus. Ground truth was generated from consensus VE results and image information from enhanced white light (eWL) and FIRE images. Data from VE and ID in Still Image (IDSM) and Video (IDVM) modes were evaluated against ground truth. Overall sensitivity of VE, IDSM, and IDVM evaluated against ground truth were 0.94, 0.884, and 0.848, respectively, for Actual Incipient Caries (AIC) detection, and 0.95, 0.916, and 0.883, respectively, for PIL detection. Sensitivity of ID in both modes was > 90% that of VE, thus demonstrating non-inferiority of IDSM and IDVM to VE. The investigated eWL and fluorescence device is clinically effective and at least as good as expert VE in detecting PIL. An enhanced white light device with FIRE technology can be used, in Video or Still Image Detection modes, as an aid to caries diagnosis.

  4. Positron emission mammography (PEM): Effect of activity concentration, object size, and object contrast on phantom lesion detection

    SciTech Connect

    MacDonald, Lawrence R.; Wang, Carolyn L.; Eissa, Marna; Haseley, David; Kelly, Mary M.; Liu, Franklin; Parikh, Jay R.; Beatty, J. David; Rogers, James V.

    2012-10-15

    Purpose: To characterize the relationship between lesion detection sensitivity and injected activity as a function of lesion size and contrast on the PEM (positron emission mammography) Flex Solo II scanner using phantom experiments. Methods: Phantom lesions (spheres 4, 8, 12, 16, and 20 mm diameter) were randomly located in uniform background. Sphere activity concentrations were 3 to 21 times the background activity concentration (BGc). BGc was a surrogate for injected activity; BGc ranged from 0.44-4.1 kBq/mL, corresponding to 46-400 MBq injections. Seven radiologists read 108 images containing zero, one, or two spheres. Readers used a 5-point confidence scale to score the presence of spheres. Results: Sensitivity was 100% for lesions {>=}12 mm under all conditions except for one 12 mm sphere with the lowest contrast and lowest BGc (60% sensitivity). Sensitivity was 100% for 8 mm spheres when either contrast or BGc was high, and 100% for 4 mm spheres only when both contrast and BGc were highest. Sphere contrast recovery coefficients (CRC) were 49%, 34%, 26%, 14%, and 2.8% for the largest to smallest spheres. Cumulative specificity was 98%. Conclusions: Phantom lesion detection sensitivity depends more on sphere size and contrast than on BGc. Detection sensitivity remained {>=}90% for injected activities as low as 100 MBq, for lesions {>=}8 mm. Low CRC in 4 mm objects results in moderate detection sensitivity even for 400 MBq injected activity, making it impractical to optimize injected activity for such lesions. Low CRC indicates that when lesions <8 mm are observed on PEM images they are highly tracer avid with greater potential of clinical significance. High specificity (98%) suggests that image statistical noise does not lead to false positive findings. These results apply to the 85 mm thick object used to obtain them; lesion detectability should be better (worse) for thinner (thicker) objects based on the reduced (increased) influence of photon attenuation.

  5. Redundancy relations and robust failure detection

    NASA Technical Reports Server (NTRS)

    Chow, E. Y.; Lou, X. C.; Verghese, G. C.; Willsky, A. S.

    1984-01-01

    All failure detection methods are based on the use of redundancy, that is on (possible dynamic) relations among the measured variables. Consequently the robustness of the failure detection process depends to a great degree on the reliability of the redundancy relations given the inevitable presence of model uncertainties. The problem of determining redundancy relations which are optimally robust in a sense which includes the major issues of importance in practical failure detection is addressed. A significant amount of intuition concerning the geometry of robust failure detection is provided.

  6. Detection and Classification of Thyroid Follicular Lesions Based on Nuclear Structure from Histopathology Images

    PubMed Central

    Wang, Wei; Ozolek, John A.; Rohde, Gustavo K.

    2010-01-01

    Follicular lesions of the thyroid are traditionally difficult and tedious challenges in diagnostic surgical pathology in part due to lack of obvious discriminatory cytological and microarchitectural features. We describe a computerized method to detect and classify follicular adenoma of the thyroid, follicular carcinoma of the thyroid, and normal thyroid based on the nuclear chromatin distribution from digital images of tissue obtained by routine histological methods. Our method is based on determining whether a set of nuclei, obtained from histological images using automated image segmentation, is most similar to sets of nuclei obtained from normal or diseased tissues. This comparison is performed utilizing numerical features, a support vector machine, and a simple voting strategy. We also describe novel methods to identify unique and defining chromatin patterns pertaining to each class. Unlike previous attempts in detecting and classifying these thyroid lesions using computational imaging, our results show that our method can automatically classify the data pertaining to 10 different human cases with 100% accuracy after blind cross validation using at most 43 nuclei randomly selected from each patient. We conclude that nuclear structure alone contains enough information to automatically classify the normal thyroid, follicular carcinoma, and follicular adenoma, as long as groups of nuclei (instead of individual ones) are used. We also conclude that the distribution of nuclear size and chromatin concentration (how tightly packed it is) seem to be discriminating features between nuclei of follicular adenoma, follicular carcinoma, and normal thyroid. PMID:20099247

  7. Image-detected 'probably benign' breast lesions: a significant reason for referral from primary care.

    PubMed

    Brennan, M E; Houssami, N

    2006-10-01

    In Australia, and many health care provider systems, primary care physicians are the first to see women with breast symptoms and are responsible for making decisions on whether to investigate and when to refer to specialist teams. We present an audit of new patient referrals from primary care triaged to a 'low-risk' (low likelihood of cancer) clinic on the basis of benign findings. The most common reason for referral was 'breast lump' (38%) followed by 'image-detected' abnormality (26%.) We have identified that (outside of population screening services) many women are being referred from primary care to specialist clinics for management of screen-detected lesions considered benign on imaging. Further research is needed to identify the reasons for such referrals and to develop appropriate educational strategies and clinical policy, both for the primary care and the specialist breast practitioner.

  8. Machine learning algorithm for automatic detection of CT-identifiable hyperdense lesions associated with traumatic brain injury

    NASA Astrophysics Data System (ADS)

    Keshavamurthy, Krishna N.; Leary, Owen P.; Merck, Lisa H.; Kimia, Benjamin; Collins, Scott; Wright, David W.; Allen, Jason W.; Brock, Jeffrey F.; Merck, Derek

    2017-03-01

    Traumatic brain injury (TBI) is a major cause of death and disability in the United States. Time to treatment is often related to patient outcome. Access to cerebral imaging data in a timely manner is a vital component of patient care. Current methods of detecting and quantifying intracranial pathology can be time-consuming and require careful review of 2D/3D patient images by a radiologist. Additional time is needed for image protocoling, acquisition, and processing. These steps often occur in series, adding more time to the process and potentially delaying time-dependent management decisions for patients with traumatic brain injury. Our team adapted machine learning and computer vision methods to develop a technique that rapidly and automatically detects CT-identifiable lesions. Specifically, we use scale invariant feature transform (SIFT)1 and deep convolutional neural networks (CNN)2 to identify important image features that can distinguish TBI lesions from background data. Our learning algorithm is a linear support vector machine (SVM)3. Further, we also employ tools from topological data analysis (TDA) for gleaning insights into the correlation patterns between healthy and pathological data. The technique was validated using 409 CT scans of the brain, acquired via the Progesterone for the Treatment of Traumatic Brain Injury phase III clinical trial (ProTECT_III) which studied patients with moderate to severe TBI4. CT data were annotated by a central radiologist and included patients with positive and negative scans. Additionally, the largest lesion on each positive scan was manually segmented. We reserved 80% of the data for training the SVM and used the remaining 20% for testing. Preliminary results are promising with 92.55% prediction accuracy (sensitivity = 91.15%, specificity = 93.45%), indicating the potential usefulness of this technique in clinical scenarios.

  9. CXCR-4 Targeted, Short Wave Infrared (SWIR) Emitting Nanoprobes for Enhanced Deep Tissue Imaging and Micrometastatic Cancer Lesion Detection.

    PubMed

    Zevon, Margot; Ganapathy, Vidya; Kantamneni, Harini; Mingozzi, Marco; Kim, Paul; Adler, Derek; Sheng, Yang; Tan, Mei Chee; Pierce, Mark; Riman, Richard E; Roth, Charles M; Moghe, Prabhas V

    2015-12-16

    Realizing the promise of precision medicine in cancer therapy depends on identifying and tracking cancerous growths to maximize treatment options and improve patient outcomes. This goal of early detection remains unfulfilled by current clinical imaging techniques that fail to detect lesions due to their small size and suborgan localization. With proper probes, optical imaging techniques can overcome this by identifying the molecular phenotype of tumors at both macroscopic and microscopic scales. In this study, the first use of nanophotonic short wave infrared technology is proposed to molecularly phenotype small lesions for more sensitive detection. Here, human serum albumin encapsulated rare-earth nanoparticles (ReANCs) with ligands for targeted lesion imaging are designed. AMD3100, an antagonist to CXCR4 (a classic marker of cancer metastasis) is adsorbed onto ReANCs to form functionalized ReANCs (fReANCs). fReANCs are able to preferentially accumulate in receptor positive lesions when injected intraperitoneally in a subcutaneous tumor model. fReANCs can also target subtissue microlesions at a maximum depth of 10.5 mm in a lung metastatic model of breast cancer. Internal lesions identified with fReANCs are 2.25 times smaller than those detected with ReANCs. Thus, an integrated nanoprobe detection platform is presented, which allows target-specific identification of subtissue cancerous lesions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Improvement of mammographic lesion detection by fusion of information from different views

    NASA Astrophysics Data System (ADS)

    Paquerault, Sophie; Petrick, Nicholas; Chan, Heang-Ping; Sahiner, Berkman

    2001-07-01

    In screening mammography, two standard views, craniocaudal (CC) and medio-lateral oblique (MLO), are commonly taken, and radiologists use information from the two views for lesion detection and diagnosis. Current computer-aided diagnosis (CAD) systems are designed to detect lesions on each view separately. We are developing a CAD method that utilizes information from the two views to reduce false-positives (FPs). Our two-view detection scheme consists of two main stages, a one-view pre-screening stage and a two-view correspondence stage. The one-view and two-view scores are then fused to estimate the likelihood that an object is a true mass. In this study, we analyzed the effectiveness of the proposed fusion scheme for FP reduction and its dependence on the number of objects per image in the pre-screening stage. The preliminary results demonstrate that the fusion of information from the CC and MLO views significantly reduced the FP rate in comparison to the one-view scheme. When the pre-screening stage produced 10 objects per image, the two-view fusion technique reduced the FP rate from an average of 2.1 FPs/image in our current one-view CAD scheme to 1.2 FPs/image at a sensitivity of 80%. The results also indicate that the improvement in the detection accuracy was essentially independent of the number of initial objects per image obtained at the pre-screening stage for this data set.

  11. [Efficacy of early cerebral MR in the detection of brain lesions in high risk preterm infants compared with conventional US].

    PubMed

    Vendemmia, M; Millet, V; Simeoni, U; Girard, N; Paludetto, R

    2004-01-01

    To identify the efficacy of early cerebral MR, performed in the first month of birth, in the detection of brain lesions in high risk preterm infants, compared with conventional US, we recruited into the study a group of 30 preterm infants born at or below a gestational age of 30 weeks, who had a pathologic scan. The findings on US were compared with those of the early MR scan, performed in the same days, the results of which were considered as the final diagnosis. The value of cranial US as a predictor of MR signal intensity was assessed by calculating sensitivity, specificity, positive and negative predictive values. Agreement between two investigations was evaluated by calculating the K coefficient. US showed 33 haemorrhagic lesions in 25 preterms; MR showed 27 haemorrhagic lesions in 22 infants: in 16 cases MR gave the same results of US. Cranial US was reliable in detecting lesions such as GLH and IVH, but less sensitive in the definition of their size and distribution. Sensitivity of US for haemorrhagic lesions was 96.3%, PPV 78.8%, K coefficient 0.55 (p < 0.001). About the White Matter, cranial US demonstrated 20 lesions in 20 preterms; MR showed 16 lesions in 16 infants: in 3 cases MR was agree to US. US showed high reliability in the detection of cystic lesions, but significant limitations in the demonstration of non-cystic injury. We founded that normal WM echogenicity on US is not a good predictor of normal WM signal intensity on MR (30%). Sensitivity of US for WM lesions was 81.3%, PPV 65%, K coefficient 0.23 (p = 0.04). Finally US showed 4 lesions in other brain locations, MR confirmed 3 of them and discovered other 10. Sensitivity of US for these lesions was 23.1%, PPV 75%, K coefficient 0.21 (p = 0.11). We founded that cranial US is a good method for detecting GLH, IVH, HPI and severe WM lesions (cystic PVL), but it can miss non-cystic PVL, punctate haemorrhages, WMD and lesions in other brain locations, that, on the other hand, MR detects clearly.

  12. Papanicolau smear chances to be diagnostic for cervical squamous intraepithelial lesions (SIL) with or without detectable HPV DNA at in situ hybridization analysis.

    PubMed

    Sopracordevole, F; Cadorin, L; Muffato, G; De Benetti, L; Parin, A

    1993-01-01

    The Authors have correlated 39 cervical diagnostic biopsies for squamous intraepithelial lesions (SILs) with correspective Papanicolau smears (PS), with relation to the presence or the absence of HPV of oncogenic type (HPV-one) detected by in situ hybridization (ISH). Agreement between cytological and histological diagnosis was present in 14 of 16 cases with detectable HPV-one and only in 12 of 23 cases without detectable HPV-one at ISH. The importance of the HPV type in the SILs with relation to the diagnostic accuracy of Papanicolaou smears has been discussed.

  13. Macrostructural and Microstructural Brain Lesions Relate to Gait Pathology in Children With Cerebral Palsy.

    PubMed

    Meyns, Pieter; Van Gestel, Leen; Leunissen, Inge; De Cock, Paul; Sunaert, Stefan; Feys, Hilde; Duysens, Jacques; Desloovere, Kaat; Ortibus, Els

    2016-10-01

    Background Even though lower-limb motor disorders are core features of spastic cerebral palsy (sCP), the relationship with brain lesions remains unclear. Unraveling the relation between gait pathology, lower-limb function, and brain lesions in sCP is complex for several reasons; wide heterogeneity in brain lesions, ongoing brain maturation, and gait depends on a number of primary motor functions/deficits (eg, muscle strength, spasticity). Objective To use a comprehensive approach combining conventional MRI and diffusion tensor imaging (DTI) in children with sCP above 3 years old to relate quantitative parameters of brain lesions in multiple brain areas to gait performance. Methods A total of 50 children with sCP (25 bilateral, 25 unilateral involvement) were enrolled. The investigated neuroradiological parameters included the following: (1) volumetric measures of the corpus callosum (CC) and lateral ventricles (LVs), and (2) DTI parameters of the corticospinal tract (CST). Gait pathology and primary motor deficits, including muscle strength and spasticity, were evaluated by 3D gait analysis and clinical examination. Results In bilateral sCP (n = 25), volume of the LV and the subparts of the CC connecting frontal, (pre)motor, and sensory areas were most related to lower-limb functioning and gait pathology. DTI measures of the CST revealed additional relations with the primary motor deficits (n = 13). In contrast, in unilateral sCP, volumetric (n = 25) and diffusion measures (n = 14) were only correlated to lower-limb strength. Conclusions These results indicate that the combined influence of multiple brain lesions and their impact on the primary motor deficits might explain a large part of the gait pathology in sCP. © The Author(s) 2016.

  14. Are Carious Lesions in Previously Sealed Occlusal Surfaces Detected as well on Colour Photographs as by Visual Clinical Examination?

    PubMed

    Hu, Xuan; Fan, Mingwen; Mulder, Jan; Frencken, Jo E

    2016-01-01

    To compare the level of agreement between carious lesion assessments according to the visual clinical examination and the colour photograph methods. Data on the presence of enamel/dentin carious lesions in previously sealed occlusal surfaces in first molars were obtained by two trained and calibrated examiners through visual clinical examination and from colour photographs 4 years after sealing. Kappa statistics were applied to calculate agreement between assessment methods. Data analysis was performed using sign, Bowker symmetry and McNemar's tests. The prevalence of dentin carious lesions was very low. The kappa coefficients for detecting enamel/dentin carious lesions using the two assessment methods were 0.65 (CI: 0.56-0.74) for examiner 1 and 0.70 (CI: 0.62-0.78) for examiner 2. Examiner 2 observed more enamel/dentin carious lesions on colour photographs than did examiner 1 (p = 0.008). Sensitivity analyses did not confirm this outcome. There was no difference in the detection of enamel/dentin carious lesions in previously sealed occlusal surfaces using colour photographs vs visual clinical examination. The colour photograph method is therefore equivalent to the visual clinical examination in detecting enamel/dentin carious lesions. More studies are required.

  15. E-cadherin polymorphisms and susceptibility to arsenic-related skin lesions in West Bengal, India.

    PubMed

    Nriagu, Jerome; Lin, Tser-Sheng; Mazumder, Debendranath Guha; Chatterjee, Debashis

    2012-03-15

    Although suppression of E-cadherin gene (CDH1) expression and exposure to arsenic have separately been associated with skin lesions, the combined effects of this "gene-environment" interaction have not been explored previously. A population-based cross-sectional survey. This study involved 100 cases with skin lesions and 100 controls who were family members with no lesions. The subjects were recruited from villages and hamlets in northern Nadia Province, West Bengal. Each participant was required to undergo a detailed face-to-face interview; provide spot urine sample; provide saliva sample; and sign a consent form. The type and severity of skin lesions were assessed during a general medical examination of each participant in the field. The following 16 single nucleotide polymorphisms (SNPs) of the CDH1 were measured using DNA extracted from saliva samples: rs16260, rs5030625, rs155364, rs155808, rs155807, rs2303646, rs2059254, rs9925923, rs12919719, rs7188750, rs9989407, rs7196495, rs7196661, rs13689, rs12599393, and rs1862748. The main effects of SNPs on the risk for skin lesions were borderline for rs7196661 (p-value=0.092), rs7196495 (p-value=0.090), and rs12919719 (p-value=0.065); the strongest association was found for rs9989407 (p-value=0.058). Several SNPs, however, showed that the T>T genotype carriers are at higher relative risk for skin lesions compared to carriers of the C>C or C>T genotypes; these results need to be confirmed in a larger study. The main effects of some of the SNPs and genotype frequencies on the severity of skin lesions were found to be relatively weak. This is the first study that indicates that CDH1 polymorphisms can contribute to the etiology of premalignant skin lesions in people chronically exposed to arsenic in drinking water, and that this gene may be a factor in individual susceptibility to cutaneous diseases. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Diagnostic performance of direct traction MR arthrography of the hip: detection of chondral and labral lesions with arthroscopic comparison.

    PubMed

    Schmaranzer, Florian; Klauser, Andrea; Kogler, Michael; Henninger, Benjamin; Forstner, Thomas; Reichkendler, Markus; Schmaranzer, Ehrenfried

    2015-06-01

    To assess diagnostic performance of traction MR arthrography of the hip in detection and grading of chondral and labral lesions with arthroscopic comparison. Seventy-five MR arthrograms obtained ± traction of 73 consecutive patients (mean age, 34.5 years; range, 14-54 years) who underwent arthroscopy were included. Traction technique included weight-adapted traction (15-23 kg), a supporting plate for the contralateral leg, and intra-articular injection of 18-27 ml (local anaesthetic and contrast agent). Patients reported on neuropraxia and on pain. Two blinded readers independently assessed femoroacetabular cartilage and labrum lesions which were correlated with arthroscopy. Interobserver agreement was calculated using κ values. Joint distraction ± traction was evaluated in consensus. No procedure had to be stopped. There were no cases of neuropraxia. Accuracy for detection of labral lesions was 92 %/93 %, 91 %/83 % for acetabular lesions, and 92 %/88 % for femoral cartilage lesions for reader 1/reader 2, respectively. Interobserver agreement was moderate (κ = 0.58) for grading of labrum lesions and substantial (κ = 0.7, κ = 0.68) for grading of acetabular and femoral cartilage lesions. Joint distraction was achieved in 72/75 and 14/75 hips with/without traction, respectively. Traction MR arthrography safely enabled accurate detection and grading of labral and chondral lesions. • The used traction technique was well tolerated by most patients. • The used traction technique almost consistently achieved separation of cartilage layers. • Traction MR arthrography enabled accurate detection of chondral and labral lesions.

  17. Swallowing disturbance pattern relates to brain lesion location in acute stroke patients.

    PubMed

    Steinhagen, Volker; Grossmann, Annette; Benecke, Reiner; Walter, Uwe

    2009-05-01

    The relationship of brain lesion location and swallowing disturbance pattern has been poorly studied in acute stroke patients. Sixty patients with first-ever acute ischemic stroke at clearly assessed location and clinical signs of dysphagia were studied. Swallowing-related parameters rated clinically and fiberendoscopically were attention deficit, buccofacial apraxia, orofacial paresis, gag reflex, delay of pharyngeal swallow, pharyngeal contraction, larynx elevation, function of upper esophageal sphincter (UES), and aspiration severity. Attention deficit was independently predicted only by parietotemporal infarction, buccofacial apraxia by left-sided parietotemporal infarction, orofacial paresis by infarction encompassing upper motor neuron of cranial nerves, and impaired UES opening by lateral medullary infarction. Other swallowing parameters were not related to lesion topology. On posthoc analysis, pneumonia within 21 days after stroke was predicted only by insular lesion. Distinct acute brain lesion locations result in characteristic swallowing disturbance patterns. Dysphagic patients with insular stroke appear to have even higher risk of pneumonia suggesting a further associated factor promoting infection in these subjects.

  18. Diagnostic power of diffuse reflectance spectroscopy for targeted detection of breast lesions with microcalcifications.

    PubMed

    Soares, Jaqueline S; Barman, Ishan; Dingari, Narahara Chari; Volynskaya, Zoya; Liu, Wendy; Klein, Nina; Plecha, Donna; Dasari, Ramachandra R; Fitzmaurice, Maryann

    2013-01-08

    Microcalcifications geographically target the location of abnormalities within the breast and are of critical importance in breast cancer diagnosis. However, despite stereotactic guidance, core needle biopsy fails to retrieve microcalcifications in up to 15% of patients. Here, we introduce an approach based on diffuse reflectance spectroscopy for detection of microcalcifications that focuses on variations in optical absorption stemming from the calcified clusters and the associated cross-linking molecules. In this study, diffuse reflectance spectra are acquired ex vivo from 203 sites in fresh biopsy tissue cores from 23 patients undergoing stereotactic breast needle biopsies. By correlating the spectra with the corresponding radiographic and histologic assessment, we have developed a support vector machine-derived decision algorithm, which shows high diagnostic power (positive predictive value and negative predictive value of 97% and 88%, respectively) for diagnosis of lesions with microcalcifications. We further show that these results are robust and not due to any spurious correlations. We attribute our findings to the presence of proteins (such as elastin), and desmosine and isodesmosine cross-linkers in the microcalcifications. It is important to note that the performance of the diffuse reflectance decision algorithm is comparable to one derived from the corresponding Raman spectra, and the considerably higher intensity of the reflectance signal enables the detection of the targeted lesions in a fraction of the spectral acquisition time. Our findings create a unique landscape for spectroscopic validation of breast core needle biopsy for detection of microcalcifications that can substantially improve the likelihood of an adequate, diagnostic biopsy in the first attempt.

  19. Diagnostic power of diffuse reflectance spectroscopy for targeted detection of breast lesions with microcalcifications

    PubMed Central

    Soares, Jaqueline S.; Barman, Ishan; Dingari, Narahara Chari; Volynskaya, Zoya; Liu, Wendy; Klein, Nina; Plecha, Donna; Dasari, Ramachandra R.; Fitzmaurice, Maryann

    2013-01-01

    Microcalcifications geographically target the location of abnormalities within the breast and are of critical importance in breast cancer diagnosis. However, despite stereotactic guidance, core needle biopsy fails to retrieve microcalcifications in up to 15% of patients. Here, we introduce an approach based on diffuse reflectance spectroscopy for detection of microcalcifications that focuses on variations in optical absorption stemming from the calcified clusters and the associated cross-linking molecules. In this study, diffuse reflectance spectra are acquired ex vivo from 203 sites in fresh biopsy tissue cores from 23 patients undergoing stereotactic breast needle biopsies. By correlating the spectra with the corresponding radiographic and histologic assessment, we have developed a support vector machine-derived decision algorithm, which shows high diagnostic power (positive predictive value and negative predictive value of 97% and 88%, respectively) for diagnosis of lesions with microcalcifications. We further show that these results are robust and not due to any spurious correlations. We attribute our findings to the presence of proteins (such as elastin), and desmosine and isodesmosine cross-linkers in the microcalcifications. It is important to note that the performance of the diffuse reflectance decision algorithm is comparable to one derived from the corresponding Raman spectra, and the considerably higher intensity of the reflectance signal enables the detection of the targeted lesions in a fraction of the spectral acquisition time. Our findings create a unique landscape for spectroscopic validation of breast core needle biopsy for detection of microcalcifications that can substantially improve the likelihood of an adequate, diagnostic biopsy in the first attempt. PMID:23267090

  20. Cardiac motion compensation and resolution modeling in simultaneous PET-MR: a cardiac lesion detection study

    NASA Astrophysics Data System (ADS)

    Petibon, Y.; Ouyang, J.; Zhu, X.; Huang, C.; Reese, T. G.; Chun, S. Y.; Li, Q.; El Fakhri, G.

    2013-04-01

    Cardiac motion and partial volume effects (PVE) are two of the main causes of image degradation in cardiac PET. Motion generates artifacts and blurring while PVE lead to erroneous myocardial activity measurements. Newly available simultaneous PET-MR scanners offer new possibilities in cardiac imaging as MRI can assess wall contractility while collecting PET perfusion data. In this perspective, we develop a list-mode iterative reconstruction framework incorporating both tagged-MR derived non-rigid myocardial wall motion and position dependent detector point spread function (PSF) directly into the PET system matrix. In this manner, our algorithm performs both motion ‘deblurring’ and PSF deconvolution while reconstructing images with all available PET counts. The proposed methods are evaluated in a beating non-rigid cardiac phantom whose hot myocardial compartment contains small transmural and non-transmural cold defects. In order to accelerate imaging time, we investigate collecting full and half k-space tagged MR data to obtain tagged volumes that are registered using non-rigid B-spline registration to yield wall motion information. Our experimental results show that tagged-MR based motion correction yielded an improvement in defect/myocardium contrast recovery of 34-206% as compared to motion uncorrected studies. Likewise, lesion detectability improved by respectively 115-136% and 62-235% with MR-based motion compensation as compared to gating and no motion correction and made it possible to distinguish non-transmural from transmural defects, which has clinical significance given the inherent limitations of current single modality imaging in identifying the amount of residual ischemia. The incorporation of PSF modeling within the framework of MR-based motion compensation significantly improved defect/myocardium contrast recovery (5.1-8.5%, p < 0.01) and defect detectability (39-56%, p < 0.01). No statistical difference was found in PET contrast and lesion

  1. A multicenter randomized comparison between high-definition white light endoscopy and narrow band imaging for detection of gastric lesions.

    PubMed

    Ang, Tiing Leong; Pittayanon, Rapat; Lau, James Yun Wong; Rerknimitr, Rungsun; Ho, Shiaw Hooi; Singh, Rajvinder; Kwek, Andrew Boon Eu; Ang, Daphne Shih Wen; Chiu, Philip Wai Yan; Luk, Sally; Goh, Khean Lee; Ong, Jeannie Peng Lan; Tan, Jessica Yi-Lyn; Teo, Eng Kiong; Fock, Kwong Ming

    2015-12-01

    Narrow band imaging (NBI) is generally considered to be useful for lesion characterization, but not enhanced detection of gastric lesions, because of the dark endoscopic view. We tested whether the new generation of NBI (190-NBI or 290-NBI), which is twice as bright as the previous version, would improve detection of premalignant gastric lesions compared with high-definition white light endoscopy (HD-WLE). This was a multicenter prospective randomized study involving five tertiary institutions in the Asia-Pacific region. A total of 579 patients aged older than 50 years who underwent diagnostic upper gastrointestinal endoscopy were randomized to either HD-WLE or NBI. The outcome measurements were detection of intestinal metaplasia (IM), focal gastric lesions, and gastric cancers. Focal gastric lesions were detected in 83/286 (29%) and 119/293 patients (40.6%) by HD-WLE and by NBI, respectively (P=0.003). IM was detected in 22/286 patients (7.7%) by HD-WLE and in 52/293 patients (17.7%) by NBI (P<0.001). Gastric cancer were found in 7/286 (2.4%) and 3/293 patients (1%) in HD-WLE and NBI groups, respectively (P=0.189). NBI increased the detection rate of IM compared with HD-WLE.

  2. Follow-up of occult bone lesions detected at MR imaging: systematic review.

    PubMed

    Boks, Simone S; Vroegindeweij, Dammis; Koes, Bart W; Hunink, M G Myriam; Bierma-Zeinstra, Sita M A

    2006-03-01

    To perform a systematic review of the literature regarding the natural course of posttraumatic occult bone lesions (often referred to as bone bruises) detected at magnetic resonance (MR) imaging. A systematic review of the literature was performed by searching the MEDLINE database (from January 1966 to February 2003) with the keywords bone bruise, trauma, follow-up, and MRI. Keywords were linked by using the Boolean operator AND. Studies were included if all of the following criteria were fulfilled: patients sustained trauma, MR imaging was used as a diagnostic method, results of clinical or MR imaging follow-up were available, and study was written in English, Dutch, German, French, Spanish, Italian, Swedish, Danish, or Norwegian. The quality of each study was assessed by using a standardized criteria set, and kappa statistics were estimated to rate the level of agreement between the two reviewers. Results were compared with regard to study design and quality scores. The MEDLINE search identified 266 articles, 13 of which met the inclusion criteria. The quality of the included studies was moderate. The two reviewers initially agreed on 179 quality items (kappa = 0.84). The study population was generally small, and follow-up periods ranged from 1 to 73 months. Four different classification systems were used, and in two studies bone bruise was not specified. Study results suggest a generally good clinical prognosis of bone bruises. Normalization of MR imaging appearance is possible and is most often encountered after the occurrence of reticular lesions. Cartilage loss at follow-up is often found in cases of initial cartilage damage (impaction or osteochondral fracture). In general, a healing response was often encountered after sustained posttraumatic occult bone lesions. The initial MR imaging appearance appears to have prognostic value. Copyright RSNA, 2006.

  3. Detection of cervical lesions by multivariate analysis of diffuse reflectance spectra: a clinical study.

    PubMed

    Prabitha, Vasumathi Gopala; Suchetha, Sambasivan; Jayanthi, Jayaraj Lalitha; Baiju, Kamalasanan Vijayakumary; Rema, Prabhakaran; Anuraj, Koyippurath; Mathews, Anita; Sebastian, Paul; Subhash, Narayanan

    2016-01-01

    Diffuse reflectance (DR) spectroscopy is a non-invasive, real-time, and cost-effective tool for early detection of malignant changes in squamous epithelial tissues. The present study aims to evaluate the diagnostic power of diffuse reflectance spectroscopy for non-invasive discrimination of cervical lesions in vivo. A clinical trial was carried out on 48 sites in 34 patients by recording DR spectra using a point-monitoring device with white light illumination. The acquired data were analyzed and classified using multivariate statistical analysis based on principal component analysis (PCA) and linear discriminant analysis (LDA). Diagnostic accuracies were validated using random number generators. The receiver operating characteristic (ROC) curves were plotted for evaluating the discriminating power of the proposed statistical technique. An algorithm was developed and used to classify non-diseased (normal) from diseased sites (abnormal) with a sensitivity of 72 % and specificity of 87 %. While low-grade squamous intraepithelial lesion (LSIL) could be discriminated from normal with a sensitivity of 56 % and specificity of 80 %, and high-grade squamous intraepithelial lesion (HSIL) from normal with a sensitivity of 89 % and specificity of 97 %, LSIL could be discriminated from HSIL with 100 % sensitivity and specificity. The areas under the ROC curves were 0.993 (95 % confidence interval (CI) 0.0 to 1) and 1 (95 % CI 1) for the discrimination of HSIL from normal and HSIL from LSIL, respectively. The results of the study show that DR spectroscopy could be used along with multivariate analytical techniques as a non-invasive technique to monitor cervical disease status in real time.

  4. HPV-related external genital lesions among men residing in Brazil.

    PubMed

    Silva, Roberto J C; Sudenga, Staci L; Sichero, Laura; Baggio, Maria Luiza; Galan, Lenice; Cintra, Ricardo; Torres, B Nelson; Stoler, Mark; Giuliano, Anna R; Villa, Luisa L

    2017-04-08

    The aims of this study were to determine the incidence of external genital lesions (EGLs), specifically histologically confirmed condyloma (genital warts) and Penile Intraepithelial Neoplasia (PeIN), and genital HPV infection progression to EGLs among healthy men aged 18-73 residing in Brazil. Subjects included 1118 men enrolled in the HPV Infection in Men (HIM) study between July 2005 and June 2009. At each visit, EGLs were biopsied and subjected to pathological evaluation. HPV status in genital swabs and biopsies was determined by Linear Array and INNO-LiPA, respectively. Age-specific EGLs incidence and the proportion and median time to EGL development were estimated. Kaplan-Meier cumulative incidence rates at 6, 12, and 24 months were determined. During follow-up, 73 men developed an incident EGL. Men could develop multiple EGLs and there were 36 men with condyloma, 27 men with lesions suggestive of condyloma, six men with PeIN, and 20 men with non-HPV lesions. HPV-positive men who developed EGLs were younger (p=0.002) than men that did not develop lesions. Among the 815 men with HPV infection, 4% progressed to EGL with the same HPV detected in the swab. During follow up, 15.7% of genital HPV-6 and HPV-11 infections progressed to condyloma (median progression time of nine months for HPV-6 versus 6.8 months for HPV-11). Approximately 1% of HPV-16 infections progressed to PeIN with a median progression time of 25 months. HPV types covered by the 4-valent HPV vaccine were detected in 82.3% and 83.3% of condyloma and PeIN, respectively. The high burden of HPV and high frequency of progression to disease underscores the need to offer HPV prophylactic vaccination to men to reduce the overall burden of infection and diseases caused by HPV.

  5. Diffusion-Weighted Imaging with Two Different b-Values in Detection of Solid Focal Liver Lesions.

    PubMed

    Yang, Da-wei; Wang, Ke-yang; Yao, Xun; Ye, Hui-yi; Jiang, Tao; Liu, Yuan; Gao, Jia-yin; Chen, Min; Zhou, Cheng; Yang, Zheng-han

    2016-01-01

    One hundred and eighty-two consecutive patients with suspected liver disease were recruited to receive diffusion-weighted imaging (DWI) with two different b-values, in comparison with T2-weighted imaging (T2WI). The detection rate of three MR sequences in solid focal liver lesions (FLLs) and subgroup analyses were performed. Our prospective study found that DWI600 was equivalent to DWI100 and T2WI for the detection of solid FLLs overall but was significantly more accurate in the detection of malignant solid FLLs and lesions larger than 10 mm.

  6. Detection of asymmetric blotches (asymmetric structureless areas) in dermoscopy images of malignant melanoma using relative color

    PubMed Central

    Stoecker, William V.; Gupta, Kapil; Stanley, R. Joe; Moss, Randy H.; Shrestha, Bijaya

    2011-01-01

    Background Dermoscopy, also known as dermatoscopy or epiluminescence microscopy (ELM), is a non-invasive, in vivo technique, which permits visualization of features of pigmented melanocytic neoplasms that are not discernable by examination with the naked eye. One prominent feature useful for melanoma detection in dermoscopy images is the asymmetric blotch (asymmetric structureless area). Method Using both relative and absolute colors, blotches are detected in this research automatically by using thresholds in the red and green color planes. Several blotch indices are computed, including the scaled distance between the largest blotch centroid and the lesion centroid, ratio of total blotch areas to lesion area, ratio of largest blotch area to lesion area, total number of blotches, size of largest blotch, and irregularity of largest blotch. Results The effectiveness of the absolute and relative color blotch features was examined for melanoma/benign lesion discrimination over a dermoscopy image set containing 165 melanomas (151 invasive melanomas and 14 melanomas in situ) and 347 benign lesions (124 nevocellular nevi without dysplasia and 223 dysplastic nevi) using a leave-one-out neural network approach. Receiver operating characteristic curve results are shown, highlighting the sensitivity and specificity of melanoma detection. Statistical analysis of the blotch features are also presented. Conclusion Neural network and statistical analysis showed that the blotch detection method was somewhat more effective using relative color than using absolute color. The relative-color blotch detection method gave a diagnostic accuracy of about 77%. PMID:15998328

  7. Detection of breast lesion regions in ultrasound images using wavelets and order statistics.

    PubMed

    Mogatadakala, Kishore V; Donohue, Kevin D; Piccoli, Catherine W; Forsberg, Flemming

    2006-04-01

    Accurate detection and segmentation of suspicious regions within the complex and irregular tissues of the breast, as depicted with ultrasonic B scans, typically require human analysis and decision making. Tissue characterization methods for classifying suspicious regions often depend on identifying and then accurately segmenting these regions. Motivated by an ultimate goal to automate this critical identification and segmentation step for tissue characterization problems, this work examines ultrasonic signal characteristics between various regions of breast tissue broadly classified as normal tissue and breast lesions. This paper introduces a nonparametric model based on order statistics (OS) estimated from multiresolution (MR) decompositions of energy-normalized subregions. Experimental results demonstrate the classification performance of the OS-based features extracted from the tumor and normal tissue regions in multiple scans from 84 patients, which resulted in a total of 204 tumor regions (from 43 malignant and 161 benign) and 816 normal tissue regions. Performance results indicate that OS-based features achieved an area under the receiver-operator characteristic curve of 91% in the discrimination between breast lesions and surrounding normal tissues.

  8. Statistical image segmentation for the detection of skin lesion borders in UV fluorescence excitation

    NASA Astrophysics Data System (ADS)

    Ortega-Martinez, Antonio; Padilla-Martinez, Juan Pablo; Franco, Walfre

    2016-04-01

    The skin contains several fluorescent molecules or fluorophores that serve as markers of structure, function and composition. UV fluorescence excitation photography is a simple and effective way to image specific intrinsic fluorophores, such as the one ascribed to tryptophan which emits at a wavelength of 345 nm upon excitation at 295 nm, and is a marker of cellular proliferation. Earlier, we built a clinical UV photography system to image cellular proliferation. In some samples, the naturally low intensity of the fluorescence can make it difficult to separate the fluorescence of cells in higher proliferation states from background fluorescence and other imaging artifacts -- like electronic noise. In this work, we describe a statistical image segmentation method to separate the fluorescence of interest. Statistical image segmentation is based on image averaging, background subtraction and pixel statistics. This method allows to better quantify the intensity and surface distributions of fluorescence, which in turn simplify the detection of borders. Using this method we delineated the borders of highly-proliferative skin conditions and diseases, in particular, allergic contact dermatitis, psoriatic lesions and basal cell carcinoma. Segmented images clearly define lesion borders. UV fluorescence excitation photography along with statistical image segmentation may serve as a quick and simple diagnostic tool for clinicians.

  9. Shoulder Bankart lesion with posterior instability: A case report of ultrasound detection.

    PubMed

    Arai, Ryuzo; Ito, Taisuke; Okudaira, Shuzo; Matsuda, Shuichi

    2017-08-01

    Minor instability of the shoulder has recently drawn attention as a cause of shoulder pain in athletes. However, it is difficult to correctly diagnose the direction in which the humeral head translates and subluxates, and to clarify the pathology of the instability. We present a case of a 20-year-old male with an unstable shoulder who could not raise his left arm due to pain. Since 6 years prior to the onset of pain, the patient could asymptomatically perform voluntary subluxation, but it was slight and the direction of the subluxation could not be confirmed. On physical examination, the conventional apprehension test and Castagna test were positive, but the jerk test was negative. Imaging studies including arthroscopy showed a Bankart lesion associated with anterior labrum detachment. There was no posterior Bankart lesion. Due to painful anterior shoulder instability, arthroscopic Bankart repair was successfully done; however, 9 months later the patient began experiencing symptomatic subluxation of the shoulder. At this time, the conventional apprehension test and Castagna test were both negative. It was difficult to detect the direction of the subluxation, just like in the preoperative condition. We performed an ultrasonographic examination from the posterior side; this clearly revealed the posterior subluxation mechanism as posterior slide of the humeral head and anterior shift of the glenoid. Based on these findings, we modified the rehabilitation and the subluxation resolved. This case suggests that ultrasound imaging can be an effective practical option for evaluating shoulder instability, especially in cases of slight posterior subluxation.

  10. HIGH-RESOLUTION GENOMIC ARRAYS FACILITATE DETECTION OF NOVEL CRYPTIC CHROMOSOMAL LESIONS IN MYELODYSPLASTIC SYNDROMES

    PubMed Central

    O’Keefe, Christine L.; Tiu, Ramon; Gondek, Lukasz P.; Powers, Jennifer; Theil, Karl S.; Kalaycio, Matt; Lichtin, Alan; Sekeres, Mikkael A.; Maciejewski, Jaroslaw P.

    2008-01-01

    Objective Unbalanced chromosomal aberrations are common in myelodysplastic syndromes, and have prognostic implications. An increased frequency of cytogenetic changes may reflect an inherent chromosomal instability due to failure of DNA repair. Therefore, it is likely that chromosomal defects in myelodysplastic syndromes may be more frequent than predicted by metaphase cytogenetics and new cryptic lesions may be revealed by precise analysis methods. Methods We used a novel high-resolution karyotyping technique, array-based comparative genomic hybridization, to investigate the frequency of cryptic chromosomal lesions in a cohort of 38 well-characterized myelodysplastic syndromes patients; results were confirmed by microsatellite quantitative PCR or single nucleotide polymorphism analysis. Results As compared to metaphase karyotyping, chromosomal abnormalities detected by array-based analysis were encountered more frequently and in a higher proportion of patients. For example, chromosomal defects were found in patients with a normal karyotype by traditional cytogenetics. In addition to verifying common abnormalities, previously cryptic defects were found in new regions of the genome. Cryptic changes often overlapped chromosomes and regions frequently identified as abnormal by metaphase cytogenetics. Conclusion The results underscore the instability of the myelodysplastic syndromes genome and highlight the utility of array-based karyotyping to study cryptic chromosomal changes which may provide new diagnostic information. PMID:17258073

  11. Sentinel node detection and radioguided occult lesion localization in breast cancer.

    PubMed

    Trifirò, Guiseppe; Lavinia Travaini, Laura; De Cicco, Concetta; Paganelli, Giovanni

    2006-01-01

    Sentinel lymph node biopsy might replace complete axillary dissection for staging of the axilla in clinically N0 breast cancer patients and represent a significant advantage as a minimally invasive procedure, considering that about 70% of patients are found to be free from metastatic disease, yet axillary node dissection can lead to significant morbidity. In our Institute, Radioguided Occult Lesion Localization is the standard method to locate non-palpable breast lesions and the gamma probes is very effective in assisting intra-operative localization and removal, as in sentinel node biopsy. The rapid spread of sentinel lymph node biopsy has led to its use in clinical settings previously considered contraindications to sentinel lymph node biopsy. In this contest, we evaluated in a large group of patients possible factors affecting sentinel node detection and the reliability of sentinel lymph node biopsy carried out after large excisional breast biopsy. Our data confirm that a previous breast surgery does not prohibit efficient sentinel lymph node localization and sentinel lymph node biopsy can correctly stage the axialla in these patients.

  12. The role of second-look ultrasound of BIRADS-3 mammary lesions detected by breast MR imaging.

    PubMed

    Fiaschetti, V; Salimbeni, C; Gaspari, E; Dembele, G Kabunda; Bolacchi, F; Cossu, E; Pistolese, C A; Perretta, T; Simonetti, G

    2012-11-01

    To asses the value of second-look ultrasound (US) for identifying BIRADS 3 (Breast Imaging Reporting Data System) mammary lesions detected by breast Magnetic Resonance imaging (MRI). From April 2008 to May 2009 330 breast MRI were performed of which 60 patients are classified as BIRADS 3. 84 lesions underwent second-look US and percutaneous vacuum biopsy Vacora system US-guided. lesions were stratified into two groups: visible on US (Group 1) and not visible on US (Group 2). The clinical impact of second-look US was studied in terms of negative predictive value (NPV). The positive predictive value (PPV) of category 3 BIRADS MRI was found to be 89%. Second look-US results detected lesions in 51% of the MRI enhancing lesions. The second look-US showed a NPV of 97%. The NPV of second look-US was significantly greater than the NPV of MRI BIRADS 3 (97% vs 89%, p<0.05). The logistic regression analysis showed a higher number of malignant lesions in group 1 than in group 2 (7vs 2, OR 3.7, p<0.05). The second-look US permitted the correct management of subcentimetric MRI BIRADS 3 lesions not visible with conventional imaging tecniques. Published by Elsevier Ireland Ltd.

  13. Effects of scalding and dehairing of pig carcasses at abattoirs on the visibility of welfare-related lesions.

    PubMed

    Carroll, G A; Boyle, L A; Teixeira, D L; van Staaveren, N; Hanlon, A; O'Connell, N E

    2016-03-01

    There is increasing interest in developing abattoir-based measures to assist in determining the welfare status of pigs. The primary aim of this study was to determine the most appropriate place on the slaughter line to conduct assessments of welfare-related lesions, namely apparent aggression-related skin lesions (hereafter referred to as 'skin lesions'), loin bruising and apparent tail biting damage. The study also lent itself to an assessment of the prevalence of these lesions, and the extent to which they were linked with production variables. Finishing pigs processed at two abattoirs on the Island of Ireland (n=1950 in abattoir A, and n=1939 in abattoir B) were used. Data were collected over 6 days in each abattoir in July 2014. Lesion scoring took place at two points on the slaughter line: (1) at exsanguination (slaughter stage 1 (SS1)), and (2) following scalding and dehairing of carcasses (slaughter stage 2 (SS2)). At both points, each carcass was assigned a skin and tail lesion score ranging from 0 (lesion absent) to 3 or 4 (severe lesions), respectively. Loin bruising was recorded as present or absent. Differences in the percentage of pigs with observable lesions of each type were compared between SS1 and SS2 using McNemar/McNemar-Bowker tests. The associations between each lesion type, and both cold carcass weight and condemnations, were examined at batch level using Pearson's correlations. Batch was defined as the group of animals with a particular farm identification code on a given day. The overall percentage of pigs with a visible skin lesion (i.e. score>0) decreased between SS1 and SS2 (P<0.001). However, the percentage of pigs with a severe skin lesion increased numerically from SS1 to SS2. The percentage of pigs with a visible tail lesion and with loin bruising also increased between SS1 and SS2 (P<0.001). There was a positive correlation between the percentage of carcasses that were partially condemned, and the percentage of pigs with skin lesions

  14. Technical Note: Development of a combined molecular breast imaging/ultrasound system for diagnostic evaluation of MBI-detected lesions.

    PubMed

    O'Connor, Michael K; Morrow, Melissa M; Tran, Thuy; Hruska, Carrie B; Conners, Amy L; Hunt, Katie N

    2017-02-01

    The purpose of this study was to perform a pilot evaluation of an integrated molecular breast imaging/ultrasound (MBI/US) system designed to enable, in real-time, the registration of US to MBI and diagnostic evaluation of breast lesions detected on MBI. The MBI/US system was constructed by modifying an existing dual-head cadmium zinc telluride (CZT)-based MBI gamma camera. The upper MBI detector head was replaced with a mesh panel, which allowed an ultrasound probe to access the breast. An optical tracking system was used to monitor the location of the ultrasound transducer, referenced to the MBI detector. The lesion depth at which ultrasound was targeted was estimated from analysis of previously acquired dual-head MBI datasets. A software tool was developed to project the US field of view onto the current MBI image. Correlation of lesion location between both modalities with real-time MBI/US scanning was confirmed in a breast phantom model and assessed in 12 patients with a breast lesion detected on MBI. Combined MBI/US scanning allowed for registration of lesions detected on US and MBI as validated in phantom experiments. In patient studies, successful registration was achieved in 8 of 12 (67%) patients, with complete registration achieved in seven and partial registration achieved in one patient. In 4 of 12 (37%) patients, lesion registration was not achieved, partially attributed to uncertainty in lesion depth estimates from MBI. The MBI/US system enabled successful registration of US to MBI in over half of patients studied in this pilot evaluation. Future studies are needed to determine if real-time, registered US imaging of MBI-detected lesions may obviate the need to proceed to more expensive procedures such as contrast-enhanced breast MRI for diagnostic workup or biopsy of MBI findings. © 2016 American Association of Physicists in Medicine.

  15. Detection and discrimination of carvone enantiomers in rats with olfactory bulb lesions.

    PubMed

    Slotnick, B; Bisulco, S

    2003-01-01

    Rats with lesions of dorsal and dorsolateral bulbar sites known to be differentially responsive to carvone enantiomers were tested for their ability to detect (+)-carvone, to discriminate between (+)-carvone from (-)-carvone, and to discriminate (+)-carvone from mixtures of both enantiomers after they had been pre-trained or not pre-trained on these tasks prior to surgery. In postoperative tests, rats pre-trained on the enantiomer discrimination problems made somewhat fewer errors than those not pre-trained, but experimental rats performed as well as controls (those that had one intact olfactory bulb) within both conditions and on each task. These results indicate that removal of most bulbar sites known to be differentially responsive to carvone enantiomers and the consequent disruption of normal patterns of bulbar input produced in response to carvones are largely without effect on the ability of rats to discriminate between these odors.

  16. Lesion area detection using source image correlation coefficient for CT perfusion imaging.

    PubMed

    Fan Zhu; Rodriguez Gonzalez, David; Carpenter, Trevor; Atkinson, Malcolm; Wardlaw, Joanna

    2013-09-01

    Computer tomography (CT) perfusion imaging is widely used to calculate brain hemodynamic quantities such as cerebral blood flow, cerebral blood volume, and mean transit time that aid the diagnosis of acute stroke. Since perfusion source images contain more information than hemodynamic maps, good utilization of the source images can lead to better understanding than the hemodynamic maps alone. Correlation-coefficient tests are used in our approach to measure the similarity between healthy tissue time-concentration curves and unknown curves. This information is then used to differentiate penumbra and dead tissues from healthy tissues. The goal of the segmentation is to fully utilize information in the perfusion source images. Our method directly identifies suspected abnormal areas from perfusion source images and then delivers a suggested segmentation of healthy, penumbra, and dead tissue. This approach is designed to handle CT perfusion images, but it can also be used to detect lesion areas in magnetic resonance perfusion images.

  17. Pathological features of betel quid-related oral epithelial lesions in taiwan with special emphasis on the tumor progression and human papillomavirus association.

    PubMed

    Chang, Kong-Chao; Su, Ih-Jen; Tsai, Sen-Tien; Shieh, Dar-Bin; Jin, Ying-Tai

    2002-01-01

    Betel quid (BQ) chewing has been a well-documented cause of oral epithelial lesions (OEL). Evolution from early hyperplastic lesions to the late or carcinomatous stage has been recognized. The pathobiological and molecular mechanism, however, remains to be elucidated. In this study, a total of 232 samples obtained from 153 cases of BQ-related OEL were retrospectively evaluated for the expression of p53 and bcl-2 in comparison with 26 cases of BQ-unrelated lesions (n = 29). The possible role of human papillomavirus (HPV) was also investigated. These BQ-related OELs included verrucous hyperplasia (VIH, n = 57, 24.6%), epithelial dysplasia (n = 23, 9.9%), verrucous carcinoma (VC, n = 5, 2.1%) and squamous cell carcinoma (SCC, n = 106, 45.7%). Fifty-four cases (35.3%) had multiple lesions. In comparison with the BQ-unrelated OELs, the characteristics of BQ-related OELs were a younger age, male predilection and multicentricity. In contrast to the tongue in BQ-unrelated OELs, the most common site for all types of BQ-related lesions was the buccal mucosa. Immunohistochemical studies of BQ-related lesions showed p53 staining in 30% of dysplasia and 38% of SCC, but a consistent absence in VH and VC. The cases with p53-positive SCC had a higher recurrence rate than p53-negative ones. Bcl-2 expression was negligible for all types of lesions. HPV-6/11 was detectable in 10% of dysplasia and 13% of SCC, but in neither VH nor VC. HPV-16/18, however, was consistently negative for all types of lesions. Our data suggest that p53, but not bcl-2, may play a role in tumor progression of BQ-related OELs, and that VH and VC are distinct and closely related histological lesions. The consistent absence of the malignant-type HPV in all BQ-related lesions suggests that HPV plays an insignificant role in the tumorigenesis of BQ-related oral cancers, although a cooperative role may exist between the benign-type HPV and BQ chewing. Copyright 2002 S. Karger AG, Basel

  18. Detection of small human cerebral cortical lesions with MRI under different levels of Gaussian smoothing: applications in epilepsy

    NASA Astrophysics Data System (ADS)

    Cantor-Rivera, Diego; Goubran, Maged; Kraguljac, Alan; Bartha, Robert; Peters, Terry

    2010-03-01

    The main objective of this study was to assess the effect of smoothing filter selection in Voxel-Based Morphometry studies on structural T1-weighted magnetic resonance images. Gaussian filters of 4 mm, 8 mm or 10 mm Full Width at High Maximum are commonly used, based on the assumption that the filter size should be at least twice the voxel size to obtain robust statistical results. The hypothesis of the presented work was that the selection of the smoothing filter influenced the detectability of small lesions in the brain. Mesial Temporal Sclerosis associated to Epilepsy was used as the case to demonstrate this effect. Twenty T1-weighted MRIs from the BrainWeb database were selected. A small phantom lesion was placed in the amygdala, hippocampus, or parahippocampal gyrus of ten of the images. Subsequently the images were registered to the ICBM/MNI space. After grey matter segmentation, a T-test was carried out to compare each image containing a phantom lesion with the rest of the images in the set. For each lesion the T-test was repeated with different Gaussian filter sizes. Voxel-Based Morphometry detected some of the phantom lesions. Of the three parameters considered: location,size, and intensity; it was shown that location is the dominant factor for the detection of the lesions.

  19. Close association between metal allergy and nail lichen planus: detection of causative metals in nail lesions.

    PubMed

    Nishizawa, A; Satoh, T; Yokozeki, H

    2013-02-01

    Lichen planus (LP) is a common skin disorder of unknown aetiology that affects the skin, mucous membranes and nails. Although metal allergies have been implicated in the development of oral LP (OLP), the contribution of these allergies to nail LP (NLP) has yet to be studied in detail. To elucidate the link between metal allergy and NLP. We retrospectively analysed 115 LP patients with respect to the contribution of metals to either NLP or OLP. We also attempted to detect the specific metals involved in these nail lesions. Of the 79 patients that received a metal patch test (PT), 24 (30%) were positive for at least one of the metal compounds tested. Notably, the prevalence of positive reactions to metals in the NLP patients was significantly higher as compared with the OLP patients (59% vs. 27%, P < 0.05). Among the 10 PT-positive patients with NLP, improvement of the skin lesions was seen in six of the patients after removal of dental materials containing causative metals or systemic disodium cromoglycate therapy. On the other hand, only 3 of 16 PT-positive patients with OLP exhibited improvement after the removal of dental materials. Causative metals in the dental fillings/braces were detected in the involved nail tissues. This study suggests that metal allergies are more closely associated with NLP vs. OLP, and that deposited metals in the nail apparatus contribute to the development of lichenoid tissue reactions in the nail bed and matrix. © 2012 The Authors. Journal of the European Academy of Dermatology and Venereology © 2012 European Academy of Dermatology and Venereology.

  20. Detection of glass particles on bone lesions using SEM-EDS.

    PubMed

    Montoriol, Romain; Guilbeau-Frugier, Céline; Chantalat, Elodie; Roumiguié, Mathieu; Delisle, Marie-Bernadette; Payré, Bruno; Telmon, Norbert; Savall, Frédéric

    2017-05-23

    The problem of identifying the wounding agent in forensic cases is recurrent. Moreover, when several tools are involved, distinguishing the origin of lesions can be difficult. Scanning electron microscopy (SEM)/energy dispersive X-ray analysis (EDS) equipment is increasingly available to the scientific and medical community, and some studies have reported its use in forensic anthropology. However, at our knowledge, no study has reported the use of SEM-EDS in forensic cases involving glass tools, whether in case reports or experiments. We performed an experimental study on human rib fragments, on which we manually created wounds using fragments of window and mirror glass. SEM-EDS was executed on samples without any further preparation on low vacuum mode, then on the same samples after defleshing them completely by boiling them. Window and mirror glass particles were detected on experimental wounds. Both had silica in their spectra, and the opaque side of the mirror contained titanium, allowing for their identification. Boiling and defleshing the bone samples involved a loss of information in terms of the number of wounds detected as positive for glass particles and in the number of glass particles detected, for both window and mirror glass. We suggest the analysis of wounds with suspected glass particles using low vacuum mode and with no defleshment by boiling.

  1. ROC curve analysis of lesion detectability on phantoms: comparison of digital spot mammography with conventional spot mammography.

    PubMed

    Yip, W M; Pang, S Y; Yim, W S; Kwok, C S

    2001-07-01

    Although conventional screen--film mammography has excellent spatial resolution and is commonly used as a screening tool, certain inherent limitations prevent its further improvement. New digital mammography techniques, despite lower spatial resolution than screen--film mammography, may overcome these limitations. This study compared lesion detectability between charge coupled device-based digital spot mammography and conventional spot mammography. A total of 100 sets of images of specially designed breast phantoms was acquired, with variable background achieved by overlapping several layers of grapefruit fibre on a 4 cm thick lucite slab, using both modalities. 75 sets were "normal" images and 25 sets were images with simulated lesions. Four radiologists assessed the images according to a five-point confidence scale. The results were used to construct receiver operating characteristic curves. No statistical difference was observed between the two sets of curves for individual radiologists as well as pooled data. The lower spatial resolution of digital mammography was compensated for by its higher contrast sensitivity relative to conventional spot mammography.

  2. CXCR-4 Targeted, Short Wave Infrared (SWIR) Emitting Nanoprobes for Enhanced Deep Tissue Imaging and Micrometastatic Lesion Detection

    PubMed Central

    Zevon, Margot; Ganapathy, Vidya; Kantamneni, Harini; Mingozzi, Marco; Kim, Paul; Adler, Derek; Sheng, Yang; Tan, Mei Chee; Pierce, Mark; Riman, Richard E.; Roth, Charles M.; Moghe, Prabhas V.

    2016-01-01

    Realizing the promise of precision medicine in cancer therapy depends on identifying and tracking of cancerous growths in order to maximize treatment options and improve patient outcomes. However, this goal of early detection remains unfulfilled by current clinical imaging techniques that fail to detect diseased lesions, due to their small size and sub-organ localization. With proper probes, optical imaging techniques can overcome this limitation by identifying the molecular phenotype of tumors at both macroscopic and microscopic scales. In this study, we propose the first use of nanophotonic short wave infrared technology to molecularly phenotype small sub-surface lesions for more sensitive detection and improved patient outcomes. To this end, we designed human serum albumin encapsulated rare-earth (RE) nanoparticles (ReANCs)[1, 2] with ligands for targeted lesion imaging. AMD3100, an antagonist to CXCR4 (a chemokine receptor involved in cell motility and a classic marker of cancer metastasis) was adsorbed onto ReANCs to form functionalized ReANCs (fReANCs). Functionalized nanoparticles were able to discriminate and preferentially accumulate in receptor positive lesions when injected intraperitoneally in a subcutaneous tumor model. Additionally, fReANCs, administered intravenously, were able to target sub-tissue tumor micro-lesions, at a maximum depth of 10.5 mm, in a lung metastatic model of breast cancer. Internal lesions identified with fReANCs were 2.25 times smaller than those detected with unfunctionalized ReANCs (p < .01) with the smallest tumor being 18.9 mm3. Thus, we present an integrated nanoprobe detection platform that allows target-specific identification of sub-tissue cancerous lesions. PMID:26514367

  3. Ulcerogenic risk assessment of diets for pigs in relation to gastric lesion prevalence

    PubMed Central

    2013-01-01

    Background Gastric ulcers in fattening pigs from intensive pork production can cause sudden deaths on farm and the grinding intensity of the diet appears to be among the risk factors. The objective of this work is to adopt the latest laboratory tests and thresholds for the ulcerogenic risk assessment of diets from experimental reports and verify the class of risk in relation to gastric lesion prevalence in reared finishers. Results Specificity and accuracy of feed safety tests based on the ulcerogenic risk of feed associated with the particle size distribution of diets were calculated on the occurrence of gastric lesions observed at a slaughterhouse: 41 lard-type hogs, fed with two diets [pelleted (n = 21 pigs) vs. mixed meal (n = 20 pigs)], analyzed at the laboratory of our Institute, were involved. Gross inspection at the abattoir allowed the identification of the development of macroscopic gastric lesions in the pigs (13/21) fed with a pelleted complete diet, ranked in Class 1 (high ulcerogenic risk) on laboratory assessment. Breakdown of gastric lesion severity: hyperkeratosis (13/13), mucosal erosions (11/13) and bleeding ulcers (2/13). This occurrence was compared to the morphology of stomach mucosa from 20 finishers fed with a mixed meal diet, ranked in Class 3 (low ulcerogenic risk), in which no gastric lesions were observed. Very fine particle (VFP) mass (<0.4 mm) according to cut off thresholds (>36%) for the safety ranking of diets, showed: 100% positive predictive value (PPV); 100% specificity; 88.1% accuracy; 72.2% sensitivity. Conclusions Three factors emerged: the elevated mass (42.6%) of <0.4 mm particles in the pelleted complete diet confirmed the associated risk rank in Class 1 assessed by laboratory procedures, as gastric lesions were selectively observed in 61.9% of finishers fed with the high risk diet; in these animals, macroscopic gastric lesions occurred within four weeks and showed a sub-clinical course, independently of severity

  4. Sound lateralisation in patients with left or right cerebral hemispheric lesions: relation with unilateral visuospatial neglect

    PubMed Central

    Tanaka, H.; Hachisuka, K.; Ogata, H.

    1999-01-01

    OBJECTIVES—To localise the brain lesion that causes disturbances of sound lateralisation and to examine the correlation between such deficit and unilateral visuospatial neglect.
METHOD—There were 29 patients with right brain damage, 15 patients with left brain damage, and 22 healthy controls, who had normal auditory and binaural thresholds. A device was used that delivered sound to the left and right ears with an interaural time difference using headphones. The amplitude (an index of ability to detect sound image shifts from the centre) and midpoint (an index of deviation of the interaural time difference range perceived as the centre) parameters of interaural time difference were analysed in each subject using 10 consecutive stable saw toothed waves.
RESULTS—The amplitude of interaural time difference was significantly higher in patients with right brain damage than in controls. The midpoint of the interaural time difference was significantly more deviated in patients with right brain damage than in those with left brain damage and controls (p<0.05). Patients with right brain damage with lesions affecting both the parietal lobe and auditory pathway showed a significantly higher amplitude and deviated midpoint than the controls, whereas right brain damage with involvement of only the parietal lobe showed a midpoint significantly deviated from the controls (p<0.05). Abnormal sound lateralisation correlated with unilateral visuospatial neglect (p<0.05).
CONCLUSIONS—The right parietal lobe plays an important part in sound lateralisation. Sound lateralisation is also influenced by lesions of the right auditory pathway, although the effect of such lesions is less than that of the right parietal lobe. Disturbances of sound lateralisation correlate with unilateral visuospatial neglect.

 PMID:10486395

  5. Diagnostic sensitivity and interobserver agreement of radiography and ultrasonography for detecting trochlear ridge osteochondrosis lesions in the equine stifle.

    PubMed

    Beccati, Francesca; Chalmers, Heather J; Dante, Sara; Lotto, Eleonora; Pepe, Marco

    2013-01-01

    Osteochondrosis lesions commonly occur on the femoral trochlear ridges in horses and radiography and ultrasonography are routinely used to diagnose these lesions. However, poor correlation has been found between radiographic and arthroscopic findings of affected trochlear ridges. Interobserver agreement for ultrasonographic diagnoses and correlation between ultrasonographic and arthroscopic findings have not been previously described. Objectives of this study were to describe diagnostic sensitivity and interobserver agreement of radiography and ultrasonography for detecting and grading osteochondrosis lesions of the equine trochlear ridges, using arthroscopy as the reference standard. Twenty-two horses were sampled. Two observers independently recorded radiographic and ultrasonographic findings without knowledge of arthroscopic findings. Imaging findings were compared between observers and with arthroscopic findings. Agreement between observers was moderate to excellent (κ 0.48-0.86) for detecting lesions using radiography and good to excellent (κ 0.74-0.87) for grading lesions using radiography. Agreement between observers was good to excellent (κ 0.78-0.94) for detecting lesions using ultrasonography and very good to excellent (κ 0.86-0.93) for grading lesions using ultrasonography. Diagnostic sensitivity was 84-88% for radiography and 100% for ultrasonography. Diagnostic specificity was 89-100% for radiography and 60-82% for ultrasonography. Agreement between radiography and arthroscopy was good (κ 0.64-0.78). Agreement between ultrasonography and arthroscopy was very good to excellent (κ 0.81-0.87). Findings from this study support ultrasound as a preferred method for predicting presence and severity of osteochondrosis lesions involving the femoral trochlear ridges in horses. © 2012 Veterinary Radiology & Ultrasound.

  6. Detecting Intracranial Vessel Wall Lesions With 7T-Magnetic Resonance Imaging: Patients With Posterior Circulation Ischemia Versus Healthy Controls.

    PubMed

    Harteveld, Anita A; van der Kolk, Anja G; van der Worp, H Bart; Dieleman, Nikki; Zwanenburg, Jaco J M; Luijten, Peter R; Hendrikse, Jeroen

    2017-09-01

    Vessel wall magnetic resonance imaging sequences have been developed to directly visualize the intracranial vessel wall, enabling detection of vessel wall changes, including those that have not yet caused luminal narrowing. In this study, vessel wall lesion burden was assessed in patients with recent posterior circulation ischemia using 7T-magnetic resonance imaging and compared with matched healthy controls. Fifty subjects (25 patients and 25 matched healthy controls) underwent 7T-magnetic resonance imaging with an intracranial vessel wall sequence before and after contrast administration. Two raters scored the presence and contrast enhancement of arterial wall lesions in individual segments of the circle of Willis and its primary branches. Total burden and distribution of vessel wall lesions and lesion characteristics (configuration, thickening pattern, and contrast enhancement) were compared both between and within both groups. Overall, vessel wall lesion burden and distribution were comparable between patients and controls. Regarding individual arterial segments, only vessel wall lesions in the posterior cerebral artery were more frequently observed in patients (18.0%) than in controls (5.4%; P=0.003). Many of these lesions showed enhancement, both in patients (48.9%) and in controls (43.5%; P=0.41). In patients, the proportion of enhancing lesions was higher in the posterior circulation (53.3%) than in the anterior circulation (20.6%; P=0.008). Although overall intracranial vessel wall lesion burden and contrast enhancement were comparable between patients with recent posterior circulation ischemia and healthy controls, this study also revealed significant differences between the 2 groups, suggesting an association between posterior circulation lesion burden/enhancement and ischemic events. URL: http://www.trialregister.nl. Unique identifier: NTR5688. © 2017 American Heart Association, Inc.

  7. Narrow-band imaging versus white light for the detection of proximal colon serrated lesions: a randomized, controlled trial.

    PubMed

    Rex, Douglas K; Clodfelter, Ryan; Rahmani, Farrah; Fatima, Hala; James-Stevenson, Toyia N; Tang, John C; Kim, Hak Nam; McHenry, Lee; Kahi, Charles J; Rogers, Nicholas A; Helper, Debra J; Sagi, Sashidhar V; Kessler, William R; Wo, John M; Fischer, Monika; Kwo, Paul Y

    2016-01-01

    The value of narrow-band imaging (NBI) for detecting serrated lesions is unknown. To assess NBI for the detection of proximal colon serrated lesions. Randomized, controlled trial. Two academic hospital outpatient units. Eight hundred outpatients 50 years of age and older with intact colons undergoing routine screening, surveillance, or diagnostic examinations. Randomization to colon inspection in NBI versus white-light colonoscopy. The number of serrated lesions (sessile serrated polyps plus hyperplastic polyps) proximal to the sigmoid colon. The mean inspection times for the whole colon and proximal colon were the same for the NBI and white-light groups. There were 204 proximal colon lesions in the NBI group and 158 in the white light group (P = .085). Detection of conventional adenomas was comparable in the 2 groups. Lack of blinding, endoscopic estimation of polyp location. NBI may increase the detection of proximal colon serrated lesions, but the result in this trial did not reach significance. Additional study of this issue is warranted. ( NCT01572428.). Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  8. Advances in finite element simulations of elastosonography for breast lesion detection.

    PubMed

    Celi, Simona; Di Puccio, Francesca; Forte, Paola

    2011-08-01

    inclusion (loosely bonded) a strain gradient is observed independently from the elastic modulus contrast. The multivariate analyses reveal that the strain contrast depends linearly on the relative stiffness between the lesion and the healthy tissue and not linearly on the interface friction coefficient. The anthropomorphic model shows other interesting features, such as the layer or curvature effects, which introduce difficulties in selecting a reference region for strain assessment. The results show that a simple axisymmetric model with linear elastic material properties can be suitable to simulate the elastosonographic procedure although the breast curvature and layer distinction play a significant role in the strain assessment.

  9. Multiple preinvasive and invasive HPV-related lesions of the anogenital tract in a female patient with HIV infection

    PubMed Central

    Clemente, Nicolò; Alessandrini, Lara; Vaccher, Emanuela; De Paoli, Antonino; Buttignol, Monica; Canzonieri, Vincenzo; Sopracordevole, Francesco

    2017-01-01

    Abstract Rationale: Patients with human immunodeficiency virus (HIV) infection have been shown to be at increased risk for high-risk human papillomavirus (HR-HPV) infection of the anogenital tract. Furthermore, in the last decades, the introduction of highly active antiretroviral therapy (HAART) has increased the longevity of these patients who now live long enough to develop HPV-related cancers; hence, the impact of HPV infection on HIV-positive patients is of increasing concern. Patient concerns: We reported the case of an HIV-positive female patient on HAART with a good virological and immunological response and with a long history of HPV-related intraepithelial and invasive lesions of the anogenital tract. Diagnoses: From 1996 to 2016, this patient was diagnosed with a high grade cervical intraepithelial neoplasia; a HR-HPV positive inguinal lymph node metastasis from clinically undetectable primary squamous cell carcinoma; a HPV-related vulvar high-grade squamous intraepithelial lesion and an invasive squamous cell carcinoma of the anus. Interventions: All the intraepithelial and invasive lesions detected were properly treated, and subsequent follow up visits with gynecologic examination, anoscopy, pap smear and anal cytology were performed. Outcomes: After a recurrence of the anal cancer and a subsequent salvage surgery with abdominoperineal resection, at the last available follow up visit no sign of disease recurrence was found. Lessons: This case stresses the importance of an accurate multidisciplinary follow-up in HIV-positive patients, including not only the routine medical, immunological, and virological evaluation, but also a periodical complete examination of the anogenital tract with cervicovaginal and anal cytology, colposcopy, high resolution anoscopy, and vulvar examination. PMID:28121939

  10. Perspectives on signet ring stromal cell tumor and related signet ring cell lesions of the gonads.

    PubMed

    Roth, Lawrence M; Ramzy, Ibrahim

    2014-11-01

    In this article, we discuss advances in our knowledge of the pathology of signet ring stromal cell tumor and related signet ring cell lesions of the ovary and a single case of signet ring stromal cell tumor of the testis. We divide ovarian signet ring cell lesions into 3 categories that reflect differences in their pathogenesis and histologic appearance. With 1 exception, all authentic cases of signet ring stromal cell tumor have been unilateral. Cases of ovarian signet ring stromal cell tumor from the literature can arise in 2 ways. The majority of cases arise multifocally from fibroma, whereas the remainder likely arise directly from the ovarian stroma. In difficult cases, immunocytochemistry provides improved diagnostic accuracy in distinguishing signet ring stromal cell tumor and its mimics from Krukenberg tumor. The most useful antibodies in this regard are epithelial membrane antigen and vimentin.

  11. A Feed-forward Neural Network Algorithm to Detect Thermal Lesions Induced by High Intensity Focused Ultrasound in Tissue

    PubMed Central

    Rangraz, Parisa; Behnam, Hamid; Shakhssalim, Naser; Tavakkoli, Jahan

    2012-01-01

    Non-invasive ultrasound surgeries such as high intensity focused ultrasound have been developed to treat tumors or to stop bleeding. In this technique, incorporation of a suitable imaging modality to monitor and control the treatments is essential so several imaging methods such as X-ray, Magnetic resonance imaging and ultrasound imaging have been proposed to monitor the induced thermal lesions. Currently, the only ultrasound imaging technique that is clinically used for monitoring this treatment is standard pulse-echo B-mode ultrasound imaging. This paper describes a novel method for detecting high intensity focused ultrasound-induced thermal lesions using a feed forward neural-network. This study was carried on in vitro animal tissue samples. Backscattered radio frequency signals were acquired in real-time during treatment in order to detect induced thermal lesions. Changes in various tissue properties including tissue's attenuation coefficient, integrated backscatter, scaling parameter of Nakagami distribution, frequency dependent scatterer amplitudes and tissue vibration derived from the backscattered radio frequency data acquired 10 minutes after treatment regarding to before treatment were used in this study. These estimated parameters were used as features of the neural network. Estimated parameters of two sample tissues including two thermal lesions and their segmented B-mode images were used along with the pathological results as training data for the neural network. The results of the study shows that the trained feed forward neural network could effectively detect thermal lesions in vitro. Comparing the estimated size of the thermal lesion (9.6 mm × 8.5 mm) using neural network with the actual size of that from physical examination (10.1 mm × 9 mm) shows that we could detect high intensity focused ultrasound thermal lesions with the difference of 0.5 mm × 0.5 mm. PMID:23724369

  12. A Feed-forward Neural Network Algorithm to Detect Thermal Lesions Induced by High Intensity Focused Ultrasound in Tissue.

    PubMed

    Rangraz, Parisa; Behnam, Hamid; Shakhssalim, Naser; Tavakkoli, Jahan

    2012-10-01

    Non-invasive ultrasound surgeries such as high intensity focused ultrasound have been developed to treat tumors or to stop bleeding. In this technique, incorporation of a suitable imaging modality to monitor and control the treatments is essential so several imaging methods such as X-ray, Magnetic resonance imaging and ultrasound imaging have been proposed to monitor the induced thermal lesions. Currently, the only ultrasound imaging technique that is clinically used for monitoring this treatment is standard pulse-echo B-mode ultrasound imaging. This paper describes a novel method for detecting high intensity focused ultrasound-induced thermal lesions using a feed forward neural-network. This study was carried on in vitro animal tissue samples. Backscattered radio frequency signals were acquired in real-time during treatment in order to detect induced thermal lesions. Changes in various tissue properties including tissue's attenuation coefficient, integrated backscatter, scaling parameter of Nakagami distribution, frequency dependent scatterer amplitudes and tissue vibration derived from the backscattered radio frequency data acquired 10 minutes after treatment regarding to before treatment were used in this study. These estimated parameters were used as features of the neural network. Estimated parameters of two sample tissues including two thermal lesions and their segmented B-mode images were used along with the pathological results as training data for the neural network. The results of the study shows that the trained feed forward neural network could effectively detect thermal lesions in vitro. Comparing the estimated size of the thermal lesion (9.6 mm × 8.5 mm) using neural network with the actual size of that from physical examination (10.1 mm × 9 mm) shows that we could detect high intensity focused ultrasound thermal lesions with the difference of 0.5 mm × 0.5 mm.

  13. Blood Pressure Control in Aging Predicts Cerebral Atrophy Related to Small-Vessel White Matter Lesions.

    PubMed

    Kern, Kyle C; Wright, Clinton B; Bergfield, Kaitlin L; Fitzhugh, Megan C; Chen, Kewei; Moeller, James R; Nabizadeh, Nooshin; Elkind, Mitchell S V; Sacco, Ralph L; Stern, Yaakov; DeCarli, Charles S; Alexander, Gene E

    2017-01-01

    Cerebral small-vessel damage manifests as white matter hyperintensities and cerebral atrophy on brain MRI and is associated with aging, cognitive decline and dementia. We sought to examine the interrelationship of these imaging biomarkers and the influence of hypertension in older individuals. We used a multivariate spatial covariance neuroimaging technique to localize the effects of white matter lesion load on regional gray matter volume and assessed the role of blood pressure control, age and education on this relationship. Using a case-control design matching for age, gender, and educational attainment we selected 64 participants with normal blood pressure, controlled hypertension or uncontrolled hypertension from the Northern Manhattan Study cohort. We applied gray matter voxel-based morphometry with the scaled subprofile model to (1) identify regional covariance patterns of gray matter volume differences associated with white matter lesion load, (2) compare this relationship across blood pressure groups, and (3) relate it to cognitive performance. In this group of participants aged 60-86 years, we identified a pattern of reduced gray matter volume associated with white matter lesion load in bilateral temporal-parietal regions with relative preservation of volume in the basal forebrain, thalami and cingulate cortex. This pattern was expressed most in the uncontrolled hypertension group and least in the normotensives, but was also more evident in older and more educated individuals. Expression of this pattern was associated with worse performance in executive function and memory. In summary, white matter lesions from small-vessel disease are associated with a regional pattern of gray matter atrophy that is mitigated by blood pressure control, exacerbated by aging, and associated with cognitive performance.

  14. Methylene Blue as a Diagnostic Aid in the Early Detection of Potentially Malignant and Malignant Lesions of Oral Mucosa.

    PubMed

    Lejoy, Abraham; Arpita, Rai; Krishna, Burde; Venkatesh, Naikmasur

    2016-05-01

    In vivo stains are the prompt resources, which have emerged in recent years to aid as clinical diagnostic tools in detecting early potentially malignant and malignant lesions. Toluidine blue, by its property of retaining in the increased DNA and RNA cellular activity areas, aids in delineating the suspicious areas. However, it is hazardous if swallowed, and has been shown to have toxicity to fibroblasts. Methylene blue has a similar chemical structure and exhibits similar physicochemical properties as toluidine blue. It is less toxic to the human body and has recently been proposed for screening some gastrointestinal or prostate tumors. The application of this material in detecting oral lesions has so far not been addressed. The objective of this study was to evaluate the sensitivity and reliability of in vivo staining with methylene blue as a diagnostic adjunct in screening for oral malignant or potentially malignant lesions. The present study involved the examination of 75 patients suspected of having oral malignant or potentially malignant lesions by methylene blue staining. The results of methylene blue uptake were compared with a simultaneous biopsy of these lesions. The overall sensitivity was 95% (100% for malignancy and 92% for potentially malignant lesions) and specificity was 70%. The positive predictive value was 91% and negative predictive value of 80% was observed in the study. We consider that methylene blue staining is a useful diagnostic adjunct in a large, community-based oral cancer screening program for high-risk individuals.

  15. Imaging of oxidation-specific epitopes with targeted nanoparticles to detect high-risk atherosclerotic lesions: Progress and future directions

    PubMed Central

    Briley-Saebo, Karen; Yeang, Calvin; Witztum, Joseph L.; Tsimikas, Sotirios

    2014-01-01

    Oxidation-specific epitopes (OSE) within developing atherosclerotic lesions are key antigens that drive innate and adaptive immune responses in atherosclerosis, leading to chronic inflammation. Oxidized phospholipids and malondialdehyde-lysine epitopes are well-characterized OSE present in human atherosclerotic lesions, particularly in pathologically defined vulnerable plaques. Using murine and human OSE-specific antibodies as targeting agents, we have developed radionuclide and magnetic resonance based nanoparticles, containing gadolinium, manganese or lipid-coated ultrasmall superparamagnetic iron oxide, to noninvasively image OSE within experimental atherosclerotic lesions. These methods quantitate plaque burden, allow detection of lesion progression and regression, plaque stabilization, and accumulation of OSE within macrophage-rich areas of the artery wall, suggesting they detect the most active lesions. Future studies will focus on using “natural” antibodies, lipopeptides and mimotopes for imaging applications. These approaches should enhance the clinical translation of this technique to image, monitor, evaluate efficacy of novel therapeutic agents and guide optimal therapy of high-risk atherosclerotic lesions. PMID:25297940

  16. (68)Ga-PSMA-PET/CT Has a Role in Detecting Prostate Cancer Lesions in Patients with Recurrent Disease.

    PubMed

    Fitzpatrick, Claire; Lynch, Olwyn; Marignol, Laure

    2017-06-01

    Early detection of recurrent πrostate cancer (PCa) lesions is paramount to allow patients to avail of localised salvage therapy options. The most significant reason for failure of salvage therapy is undetected metastatic disease. This demonstrates the need for a more accurate monitoring tool. The prostate-specific membrane antigen (PSMA) is increasingly investigated as a novel tracer for gallium 68 PET/CT to detect PCa lesions in patients with recurrent disease. The Embase, Pubmed and the Cochrane databases were searched to identify studies investigating the accuracy of (68)Ga-PSMA-PET/CT in detecting PCa lesions. Studies were analysed with regards to image analysis, sensitivity, specificity and detection rates; compared to conventional methods and with the effects of contributing characteristics. 24 studies were analysed. (68)Ga-PSMA-PET/CT was associated with sensitivity and specificity values of 33-93%, and >99% respectively. The tracer produced excellent contrast 1 h post injection. Probability of detection increases with increasing prostate-specific antigen (PSA), and at low PSA levels, is greater than that of current choline tracers. Early detection of lesions by the tracer allows alterations in follow up treatment. However, detectability may be affected by tracer trapping, androgen deprivation therapy and levels of PSMA expression. (68)Ga-PSMA PET/CT shows promise as a tool for the detection of PCa lesions in patients with suspected recurrence. However further studies with more reports on sensitivity and specificity with longer follow-up times are needed. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  17. Biomonitoring of primary aluminium industry workers: detection of micronuclei and repairable DNA lesions by alkaline SCGE.

    PubMed

    Crebelli, Riccardo; Carta, Plinio; Andreoli, Cristina; Aru, Gabriella; Dobrowolny, Gabriella; Rossi, Sabrina; Zijno, Andrea

    2002-04-26

    The genetic effects of occupational exposure to low polycyclic aromatic hydrocarbon (PAH) concentrations were investigated in primary aluminium industry workers. The study subjects were employed in a plant that uses pre-baked anode cells, and has relatively low PAH contamination. Forty-two male workers belonging to different job categories (anode fabrication, baking, rodding, electrolysis, maintenance), together with 16 male local residents with no occupational exposure to PAHs were selected for the analysis of micronuclei and DNA lesions in peripheral lymphocytes. The incidence of micronuclei determined in 1000 cytokinesis-blocked cells in each subject was not significantly different between workers and controls (8.5+/-5.4 per thousand versus 9.7+/-4.9 per thousand, respectively), nor between smokers and non-smokers (8.3+/-5.8 per thousand versus 9.2+/-5.1 per thousand), but was significantly (P<0.05) related to the subjects' age. Also the analysis of DNA damage in unstimulated and mitogen-stimulated lymphocytes by single cell gel electrophoresis (SCGE) did not show significant differences between the studied groups (average tail moment values were 0.53+/-0.53 and 0.49+/-0.45 microm in exposed subjects and controls, respectively). However, when lymphocytes were cultured in the presence of cytosine arabinoside (Ara-C, 1 microg/ml for 16h) the SCGE analysis revealed a significant (P=0.018) difference in tail moment values between aluminium workers and controls (1.73+/-1.05 microm versus 0.93+/-0.88 microm, respectively). This difference may highlight an excess of relatively stable DNA lesions, that do not affect strand integrity, and are expressed as intermediates of excision repair in stimulated cells, when gap refilling is inhibited by cytosine arabinoside (Ara-C).

  18. Prostate lesion detection and localization based on locality alignment discriminant analysis

    NASA Astrophysics Data System (ADS)

    Lin, Mingquan; Chen, Weifu; Zhao, Mingbo; Gibson, Eli; Bastian-Jordan, Matthew; Cool, Derek W.; Kassam, Zahra; Chow, Tommy W. S.; Ward, Aaron; Chiu, Bernard

    2017-03-01

    Prostatic adenocarcinoma is one of the most commonly occurring cancers among men in the world, and it also the most curable cancer when it is detected early. Multiparametric MRI (mpMRI) combines anatomic and functional prostate imaging techniques, which have been shown to produce high sensitivity and specificity in cancer localization, which is important in planning biopsies and focal therapies. However, in previous investigations, lesion localization was achieved mainly by manual segmentation, which is time-consuming and prone to observer variability. Here, we developed an algorithm based on locality alignment discriminant analysis (LADA) technique, which can be considered as a version of linear discriminant analysis (LDA) localized to patches in the feature space. Sensitivity, specificity and accuracy generated by the proposed algorithm in five prostates by LADA were 52.2%, 89.1% and 85.1% respectively, compared to 31.3%, 85.3% and 80.9% generated by LDA. The delineation accuracy attainable by this tool has a potential in increasing the cancer detection rate in biopsies and in minimizing collateral damage of surrounding tissues in focal therapies.

  19. Effects of visual fixation cues on the detectability of simulated breast lesions

    NASA Astrophysics Data System (ADS)

    Nafziger, John S.; Johnson, Jeffrey P.; Lubin, Jeffrey

    2005-04-01

    A discrepancy exists between two studies that investigated psychophysical detection of simulated lesions (e.g. gaussians or designer nodules) embedded in filtered noise images (Johnson et al, 2002; Burgess et al, 2003). Johnson et al, 2002 identified a significant difference in the slope of the contrast detail plots (CD plots) as the presentation methodology in a 2AFC task was changed from the unlike background (unpaired) to identical backgrounds (paired). In comparable experiments, Burgess et al, 2003 challenged the results by finding no difference between the slopes (both positive) of the CD plots when using paired backgrounds or unpaired backgrounds. We found that a significant difference between the two studies, namely the presence of a circular fixation cue was responsible for the discrepancy. The detection noise due to positional uncertainty was sufficient to reduce subject's threshold for small target diameters. This effect was amplified in the paired background, switching the CD plot from a negative slope (without fixation) to a positive slope (with fixation). The effect was less dramatic with the unpaired backgrounds, however intra-observer variability seemed to be reduced with fixation cues. These results significantly reduce the discrepancies in C-D characteristics between the two studies.

  20. Dye-enhanced laser fluorescence detection of caries lesions around brackets.

    PubMed

    Alencar, Cássio José Fornazari; Braga, Mariana Minatel; de Oliveira, Elisabeth; Nicolau, José; Mendes, Fausto Medeiros

    2009-11-01

    The aim was to evaluate the performance of DIAGNOdent [laser fluorescence(LF) and LFpen] devices enhanced by fluorescent dye in detecting mineral loss around brackets and comparing the inhibitory effect of bonding material on artificial demineralization, and to verify whether LF methods show the same trends of mineral loss. Brackets were bonded to premolar halves with Fuji Ortho LC, Transbond XT, and Ortho Glass LC cements (n = 15). The teeth were soaked in demineralizing solution (pH = 4.8) for 16 days. Mineral loss was calculated by atomic emission spectrometry, and lesions were measured with LF devices with dye [tetrakis N-methylpyridyl porphyrin (TMPyP)]. Groups were compared with regard to LF readings and mineral loss, and performance of caries detection was calculated. Higher mineral loss and LF-TMPyP values occurred in the resin group. LFpen-TMPyP readings were significantly higher in the demineralized groups. Correlation was observed between mineral loss and LF measurements. LF methods are capable of identifying lower demineralization around brackets bonded with resin-modified glass ionomer cements.

  1. Early detection of high-grade squamous intraepithelial lesions in the cervix with quantitative spectroscopic imaging

    PubMed Central

    Mirkovic, Jelena; Yu, Chung-Chieh; O’Donoghue, Geoff P.; Galindo, Luis; Dasari, Ramachandra; de las Morenas, Antonio; Feld, Michael; Stier, Elizabeth

    2013-01-01

    Abstract. Quantitative spectroscopy has recently been extended from a contact-probe to wide-area spectroscopic imaging to enable mapping of optical properties across a wide area of tissue. We train quantitative spectroscopic imaging (QSI) to identify cervical high-grade squamous intraepithelial lesions (HSILs) in 34 subjects undergoing the loop electrosurgical excision procedure (LEEP subjects). QSI’s performance is then prospectively evaluated on the clinically suspicious biopsy sites from 47 subjects undergoing colposcopic-directed biopsy. The results show the per-subject normalized reduced scattering coefficient at 700 nm (An) and the total hemoglobin concentration are significantly different (p<0.05) between HSIL and non-HSIL sites in LEEP subjects. An alone retrospectively distinguishes HSIL from non-HSIL with 89% sensitivity and 83% specificity. It alone applied prospectively on the biopsy sites distinguishes HSIL from non-HSIL with 81% sensitivity and 78% specificity. The findings of this study agree with those of an earlier contact-probe study, validating the robustness of QSI, and specifically An, for identifying HSIL. The performance of An suggests an easy to use and an inexpensive to manufacture monochromatic instrument is capable of early cervical cancer detection, which could be used as a screening and diagnostic tool for detecting cervical cancer in low resource countries. PMID:23843090

  2. Whole body MRI: Improved Lesion Detection and Characterization With Diffusion Weighted Techniques

    PubMed Central

    Attariwala, Rajpaul; Picker, Wayne

    2013-01-01

    Diffusion-weighted imaging (DWI) is an established functional imaging technique that interrogates the delicate balance of water movement at the cellular level. Technological advances enable this technique to be applied to whole-body MRI. Theory, b-value selection, common artifacts and target to background for optimized viewing will be reviewed for applications in the neck, chest, abdomen, and pelvis. Whole-body imaging with DWI allows novel applications of MRI to aid in evaluation of conditions such as multiple myeloma, lymphoma, and skeletal metastases, while the quantitative nature of this technique permits evaluation of response to therapy. Persisting signal at high b-values from restricted hypercellular tissue and viscous fluid also permits applications of DWI beyond oncologic imaging. DWI, when used in conjunction with routine imaging, can assist in detecting hemorrhagic degradation products, infection/abscess, and inflammation in colitis, while aiding with discrimination of free fluid and empyema, while limiting the need for intravenous contrast. DWI in conjunction with routine anatomic images provides a platform to improve lesion detection and characterization with findings rivaling other combined anatomic and functional imaging techniques, with the added benefit of no ionizing radiation. PMID:23960006

  3. Virtopsy -- noninvasive detection of occult bone lesions in postmortem MRI: additional information for traffic accident reconstruction.

    PubMed

    Buck, Ursula; Christe, Andreas; Naether, Silvio; Ross, Steffen; Thali, Michael J

    2009-05-01

    In traffic accidents with pedestrians, cyclists or motorcyclists, patterned impact injuries as well as marks on clothes can be matched to the injury-causing vehicle structure in order to reconstruct the accident and identify the vehicle which has hit the person. Therefore, the differentiation of the primary impact injuries from other injuries is of great importance. Impact injuries can be identified on the external injuries of the skin, the injured subcutaneous and fat tissue, as well as the fractured bones. Another sign of impact is a bone bruise. The bone bruise, or occult bone lesion, means a bleeding in the subcortical bone marrow, which is presumed to be the result of micro-fractures of the medullar trabeculae. The aim of this study was to prove that bleeding in the subcortical bone marrow of the deceased can be detected using the postmortem noninvasive magnetic resonance imaging. This is demonstrated in five accident cases, four involving pedestrians and one a cyclist, where bone bruises were detected in different bones as a sign of impact occurring in the same location as the external and soft tissue impact injuries.

  4. Increased detection of clue cells in smears from cervical intraepithelial lesions with reduced expression of COX-2.

    PubMed

    Figueiredo, Priscila Garcia; Sarian, Luis Otávio; Tambascia, Julia Kawamura; Simões, José Antônio; Rabelo-Santos, Silvia Helena; Discacciati, Michelle Garcia; Derchain, Sophie

    2008-10-01

    The relation between the detection of clue cells in cervical smears of women with CIN and the expression of COX-2 in these lesions were determined. Samples from 228 women, treated due to CIN and who underwent cervical conization, were obtained. Hybrid Capture II and Pap smear samples were collected immediately before performing conization. Pathological diagnoses were 11 (5%) normal cervix, 35 (15%) CIN1, 31 (14%) CIN2, and 151 (66%) CIN3. COX-2 immunoreactivity grading on the pathological specimens was based on the German ImmunoReactive score. In cervical smears, 20 fields (40x) were examined, each of them with a minimum count of 10 epithelial cells. When 20% or more of clue cells were detected the sample was considered positive for clue cells. The prevalence of clue cells was similar across histological strata (P = 0.42). Although the expression of COX-2 did not differ in lesions with varying severities (P = 0.24), there was a negative association between the expression of COX-2 and the presence of clue cells in Pap smear (OR = 0.4; 95% CI = 0.2-0.9): only 12% of women with moderate and strong expression of COX-2 had clue cells in their smears, contrasted to 22% of those with negative and weak expression of COX-2. HPV infection was associated in a borderline manner to the expression of COX-2 (P = 0.04; OR = 2.3 95% CI = 1.0-5.4). The reduced expression of COX-2 in CIN specimens may suggest that clue cells interfere with the inflammatory component of the carcinogenic process that lead to CIN.

  5. GFAP Out-Performs S100β in Detecting Traumatic Intracranial Lesions on Computed Tomography in Trauma Patients with Mild Traumatic Brain Injury and Those with Extracranial Lesions

    PubMed Central

    Silvestri, Salvatore; Brophy, Gretchen M.; Giordano, Philip; Falk, Jay L.; Braga, Carolina F.; Tan, Ciara N.; Ameli, Neema J.; Demery, Jason A.; Dixit, Neha K.; Mendes, Matthew E.; Hayes, Ronald L.; Wang, Kevin K. W.; Robertson, Claudia S.

    2014-01-01

    Abstract Both glial fibrillary acidic protein (GFAP) and S100β are found in glial cells and are released into serum following a traumatic brain injury (TBI), however, the clinical utility of S100β as a biomarker has been questioned because of its release from bone. This study examined the ability of GFAP and S100β to detect intracranial lesions on computed tomography (CT) in trauma patients and also assessed biomarker performance in patients with fractures and extracranial injuries on head CT. This prospective cohort study enrolled a convenience sample of adult trauma patients at a Level I trauma center with and without mild or moderate traumatic brain injury (MMTBI). Serum samples were obtained within 4 h of injury. The primary outcome was the presence of traumatic intracranial lesions on CT scan. There were 397 general trauma patients enrolled: 209 (53%) had a MMTBI and 188 (47%) had trauma without MMTBI. Of the 262 patients with a head CT, 20 (8%) had intracranial lesions. There were 137 (35%) trauma patients who sustained extracranial fractures below the head to the torso and extremities. Levels of S100β were significantly higher in patients with fractures, compared with those without fractures (p<0.001) whether MMTBI was present or not. However, GFAP levels were not significantly affected by the presence of fractures (p>0.05). The area under the receiver operating characteristics curve (AUC) for predicting intracranial lesions on CT for GFAP was 0.84 (0.73–0.95) and for S100β was 0.78 (0.67–0.89). However, in the presence of extracranial fractures, the AUC for GFAP increased to 0.93 (0.86–1.00) and for S100β decreased to 0.75 (0.61–0.88). In a general trauma population, GFAP out-performed S100β in detecting intracranial CT lesions, particularly in the setting of extracranial fractures. PMID:24903744

  6. Effectiveness of core biopsy for screen-detected breast lesions under 10 mm: implications for surgical management.

    PubMed

    Farshid, Gelareh; Downey, Peter; Pieterse, Steve; Gill, P Grantley

    2017-09-01

    Technical advances have improved the detection of small mammographic lesions. In the context of mammographic screening, accurate sampling of these lesions by percutaneous biopsy is crucial in limiting diagnostic surgical biopsies, many of which show benign results. Women undergoing core biopsy between January 1997 and December 2007 for <10-mm lesions are included. Patient demographics, imaging features and final histology were tabulated. Performance indices were evaluated. This audit includes 803 lesions <10 mm. Based on core histology, 345 women (43.0%) were immediately cleared of malignancy and 300 (37.4%) were referred for definitive cancer treatment. A further 157 women (19.6%) required diagnostic surgical biopsy because of indefinite or inadequate core results or radiological-pathological discordance, and one woman (0.1%) needed further imaging in 12 months. The open biopsies were malignant in 46 (29.3%) cases. The positive predictive value of malignant core biopsy was 100%. The negative predictive value for benign core results was 97.7%, and the false-negative rate was 2.6%. The lesion could not be visualized after core biopsy in 5.1% of women and in 4.0% of women with malignant core biopsies excision specimens did not contain residual malignancy. Excessive delays in surgery because of complications of core biopsy were not reported. Even at this small size range, core biopsy evaluation of screen-detected breast lesions is highly effective and accurate. A lesion miss rate of 3.1% and under-representation of lesions on core samples highlight the continued need for multidisciplinary collaboration and selective use of diagnostic surgical biopsy. © 2015 Royal Australasian College of Surgeons.

  7. Risk of arsenic-related skin lesions in Bangladeshi villages at relatively low exposure: a report from Gonoshasthaya Kendra.

    PubMed

    McDonald, Corbett; Hoque, Rezaul; Huda, Nazmul; Cherry, Nicola

    2007-09-01

    Arsenic concentrations in 25% of tube wells in Bangladesh exceed 50 microg/L, a level known to be hazardous. Levels in individual wells vary widely. We gathered data on arsenic exposure levels and skin lesion prevalence to address the lack of knowledge about risks where the average arsenic concentrations was lower. The nongovernmental organization Gonoshasthaya Kendra did three related studies of keratotic skin lesions since 2004: (1) an ecological prevalence survey among 13 705 women aged > 18 in a random sample of 53 villages; (2) a case-control study of 176 cases and age- and village-matched referents; and (3) a prevalence survey of the entire population of 11,670 in two additional villages. We calculated prevalence as a function of average arsenic concentrations as reported in the National Hydrochemical Survey, and measured arsenic concentrations in wells used by subjects in the case-control study. The prevalence of skin lesions was 0.37% in people exposed to arsenic concentrations below 5 microg/L, 0.63% at 6-50 microg/L, and 6.84% at 81 microg/L. In the case-control analysis, relative risk of skin lesions increased threefold at concentrations above 50 microg/L (P < 0.05). Little serious skin disease is likely to occur if the arsenic concentration in drinking water is kept below 50 microg/L, but ensuring this water quality will require systematic surveillance and reliable testing of all wells, which may be impractical. More research is needed on feasible prevention of toxic effects from arsenic exposure in Bangladesh.

  8. Automatic lesion boundary detection in dermoscopy images using gradient vector flow snakes

    PubMed Central

    Erkol, Bulent; Moss, Randy H.; Stanley, R. Joe; Stoecker, William V.; Hvatum, Erik

    2011-01-01

    Background Malignant melanoma has a good prognosis if treated early. Dermoscopy images of pigmented lesions are most commonly taken at × 10 magnification under lighting at a low angle of incidence while the skin is immersed in oil under a glass plate. Accurate skin lesion segmentation from the background skin is important because some of the features anticipated to be used for diagnosis deal with shape of the lesion and others deal with the color of the lesion compared with the color of the surrounding skin. Methods In this research, gradient vector flow (GVF) snakes are investigated to find the border of skin lesions in dermoscopy images. An automatic initialization method is introduced to make the skin lesion border determination process fully automated. Results Skin lesion segmentation results are presented for 70 benign and 30 melanoma skin lesion images for the GVF-based method and a color histogram analysis technique. The average errors obtained by the GVF-based method are lower for both the benign and melanoma image sets than for the color histogram analysis technique based on comparison with manually segmented lesions determined by a dermatologist. Conclusions The experimental results for the GVF-based method demonstrate promise as an automated technique for skin lesion segmentation in dermoscopy images. PMID:15691255

  9. Accuracy of magnetic resonance imaging, magnetic resonance arthrography and computed tomography for the detection of chondral lesions of the knee.

    PubMed

    Smith, Toby O; Drew, Benjamin T; Toms, Andoni P; Donell, Simon T; Hing, Caroline B

    2012-12-01

    To assess the diagnostic test accuracy of magnetic resonance imaging (MRI), magnetic resonance arthrography (MRA) and computed tomography arthrography (CTA) for the detection of chondral lesions of the patellofemoral and tibiofemoral joints. A review of published and unpublished literature sources was conducted on 22nd September 2011. All studies assessing the diagnostic test accuracy (sensitivity/specificity) of MRI or MRA or CTA for the assessment of adults with chondral (cartilage) lesions of the knee (tibiofemoral/patellofemoral joints) with surgical comparison (arthroscopic or open) as the reference test were included. Data were analysed through meta-analysis. Twenty-seven studies assessing 2,592 knees from 2,509 patients were included. The findings indicated that whilst presenting a high specificity (0.95-0.99), the sensitivity of MRA, MRI and CTA ranged from 0.70 to 0.80. MRA was superior to MRI and CTA for the detection of patellofemoral joint chondral lesions and that higher field-strength MRI scanner and grade four lesions were more accurately detected compared with lower field-strength and grade one lesions. There appeared no substantial difference in diagnostic accuracy between the interpretation from musculoskeletal and general radiologists when undertaking an MRI review of tibiofemoral and patellofemoral chondral lesions. Specialist radiological imaging is specific for cartilage disease in the knee but has poorer sensitivity to determine the therapeutic options in this population. Due to this limitation, there remains little indication to replace the 'gold-standard' arthroscopic investigation with MRI, MRA or CTA for the assessment of adults with chondral lesions of the knee. II.

  10. Ameloblastic fibroma and related lesions: a clinicopathologic study with reference to their nature and interrelationship.

    PubMed

    Chen, Yan; Li, Tie-Jun; Gao, Yan; Yu, Shi-Feng

    2005-11-01

    Ameloblastic fibroma (AF) and related lesions constitute a group of lesions, which range in biologic behavior from true neoplasms to hamartomas. The aim of this study was to elucidate the nature and interrelationship of this group of lesions. Clinical and pathological studies were undertaken retrospectively on 13 cases of AF and seven cases of ameloblastic fibro-odontoma (AFO). Thirty-three complex odontomas and 33 compound odontomas were also included for comparative purpose. Relevant follow-up data were recorded and the literature was reviewed. The majority of patients with AF (nine cases, 69.2%) were over the age of 22 years with frequent involvement (76.9%) of the posterior mandible. Tumors recurred in four of 11 patients with follow-up information and two recurrent tumors showed malignant transformation. There was no case in this series that could be designated as the so-called ameloblastic fibrodentinoma, apart from one recurrent AF in which further maturation to form only tubular dentin materials was identified. AFO tended to occur at a younger age group with an average of 9.6 years. Recurrence was noted in two of five patients with follow-up data and both recurrent lesions showed limited growth potential and further maturation into a complex odontoma. Significant differences were noted in the age and site distribution between the complex and the compound odontomas. Whilst the majority, if not all, of AFs are true neoplasms with a potential to recur and/or of malignant transformation, some, especially those occurred during childhood, could represent the primitive stage of a developing odontoma. Our data also suggests that some AFOs are hamartomatous in nature, representing a stage preceding the complex odontoma.

  11. Abnormal movement related potentials in patients with lesions of basal ganglia and anterior thalamus.

    PubMed Central

    Fève, A; Bathien, N; Rondot, P

    1994-01-01

    Movement-related cortical potentials (MRCPs) were recorded from scalp electrodes during wrist flexion in 15 dystonic patients with bilateral (nine) or unilateral (six) circumscribed lesions in the striatum (eight), pallidum (six), or anterior thalamus (one). The results were compared with those of 10 age-matched healthy volunteers. The early (BP) and late (NS') MRCP components were assessed in terms of their gradients and distribution on the scalp in Cz, C3', and C4'. The gradients of both BP and NS' components were significantly flatter in the patients with bilateral lesions than in the control subjects. Also, the BP gradient was maximum at Cz, and the NS' component was contralaterally predominant in the control subjects but not in the patients. In patients with unilateral lesions, the gradients were flatter (p < 0.05) during movement of the dystonic wrist than during movement of the normal wrist. This difference was significant for BP and NS', regardless of the location of the electrodes. Also, the normal topographic predominance of BP at Cz and of contralateral NS' disappeared. The BP and NS' components of the MRCPs are thought to reflect preparatory activity in the supplementary motor area and the primary motor cortex before movement. Reduced BP and NS' gradients in patients with both bilateral and unilateral lesions of the basal ganglia, which project towards the supplementary motor area, are consistent with this hypothesis. The bilateral nature of these reductions suggests that both the ipsilateral and the contralateral motor cortex are involved in the genesis of the MRCPs and that the dystonia in these patients is associated with impaired motor preparation. PMID:8301287

  12. Assessment of enamel-dentin caries lesions detection using bitewing PSP digital images

    PubMed Central

    TORRES, Marianna Guanaes Gomes; SANTOS, Aline da Silva; NEVES, Frederico Sampaio; ARRIAGA, Marcel Lautenschlager; CAMPOS, Paulo Sérgio Flores; CRUSOÉ-REBELLO, Iêda

    2011-01-01

    Objectives The aim of this study was to evaluate the detection of enamel-dentin occlusal caries using photostimulable phosphor plates. Material and Methods The ability to detect enamel-dentin occlusal caries in 607 premolars and molars from 47 patients between 10 and 18 years old, referred to the School of Dentistry of the Federal University of Bahia, Brazil, was evaluated based on clinical and radiographic examinations, using the criteria proposed in a previous study. A total of 156 bitewing digital images were obtained using Digora® (Soredex Medical Systems, Helsinki, Finland) phosphor plates. The plates were scanned and the images were captured and displayed on a computer screen. Image evaluation was done using Digora® for Windows 2.1 software, Soredex®. The radiologists were allowed to use enhancement tools to obtain better visibility during scoring of the teeth based on the radiographic criteria proposed in a previous study. Descriptive analysis and chi-squared proportion tests were done at 5% significance level. Results The results of clinical examination showed a higher prevalence of teeth with a straight dark line or demineralization of the occlusal fissure (score 1) and a lower prevalence of sealed teeth (score 5). In the bitewing digital images, 47 teeth presented visible radiolucency, circumscribed, in dentin under occlusal enamel (enamel-dentin caries lesions). Conclusions Correlating the clinical and radiographic findings, it was found that in the majority of teeth diagnosed by radiographic images as having enamel-dentin caries, no caries could be detected by clinical examination. PMID:21986650

  13. Cost of detecting malignant lesions by endoscopy in 2741 primary care dyspeptic patients without alarm symptoms.

    PubMed

    Vakil, Nimish; Talley, Nicholas; van Zanten, Sander Veldhuyzen; Flook, Nigel; Persson, Tore; Björck, Ewa; Lind, Tore; Bolling-Sternevald, Elisabeth

    2009-07-01

    Current guidelines recommend empirical, noninvasive approaches to manage dyspeptic patients without alarm symptoms, but concerns about missed lesions persist; the cost savings afforded by noninvasive approaches must be weighed against treatment delays. We investigated the prevalence of malignancies and other serious abnormalities in patients with dyspepsia and the cost of detecting these by endoscopy. We studied 2741 primary-care outpatients, 18-70 years in age, who met Rome II criteria for dyspepsia. Patients with alarm features (dysphagia, bleeding, weight loss, etc) were excluded. All patients underwent endoscopy. The cost and diagnostic yield of an early endoscopy strategy in all patients were compared with those of endoscopy limited to age-defined cohorts. Costs were calculated for a low, intermediate, and high cost environment. Endoscopies detected abnormalities in 635 patients (23%). The most common findings were reflux esophagitis with erosions (15%), gastric ulcers (2.7%), and duodenal ulcers (2.3%). The prevalence of upper gastrointestinal malignancy was 0.22%. If all dyspeptic patients 50 years or older underwent endoscopy, 1 esophageal cancer and no gastric cancers would have been missed. If the age threshold for endoscopy were set at 50 years, at a cost of $500/endoscopy, it would cost $82,900 (95% CI, $35,714-$250,000) to detect each case of cancer. Primary care dyspeptic patients without alarm symptoms rarely have serious underlying conditions at endoscopy. The costs associated with diagnosing an occult malignancy are large, but an age cut-off of 50 years for early endoscopy provides the best assurance that an occult malignancy will not be missed.

  14. Breath-hold [68Ga]DOTA-TOC PET/CT in neuroendocrine tumors: detection of additional lesions and effects on quantitative parameters.

    PubMed

    Zirnsak, Mariana; Bärwolf, Robert; Freesmeyer, Martin

    2016-11-08

    Respiratory motion during PET/CT acquisition generates artifacts in the form of breath-related blurring, which influences the lesion detectability and diagnostic accuracy. The goal of this study was to verify whether breath-hold [68Ga]DOTA-TOC PET/CT (bhPET) allows detection of additional foci compared to free-breathing PET/CT (fbPET), and to assess the impact of breath-holding on standard uptake values (SUV) and isocontoured volume (Vic40) in patients with neuroendocrine tumors (NET). Patients with NET (n=39) were included in this study. BhPET and fbPET characteristics of 96 lesions were compared, and correlated with standard contrast-enhanced (ce) CT and MRI for lesion verification. Quantitative parameters SUV (max and mean) and Vic40 were assessed for both methods and evaluated by linear regression and Spearman's correlation. The impact of lesion size, localization and time interval between investigations was also analyzed. bhPET identified one additional metastasis not seen at fbPET but visible at ceMRI. Another additional bhPET focus did not have a morphological correlate. At bhPET, the SUVmax and SUVmean proved significantly higher and the Vic40 significantly lower than at fbPET. Lesion size, localization and time intervals did not impact significantly on SUV or Vic40. Currently, routine use of breath-hold [68Ga]DOTA-TOC PET/CT cannot be recommended as only one additional lesion was identified. Therefore, bhPET has currently no indication in patients with NET. If technical improvements regarding PET/CT scanner sensitivity are available, bhPET should be reevaluated in the future.

  15. Contribution of Raman spectroscopy in nephrology: a candidate technique to detect hydroxyethyl starch of third generation in osmotic renal lesions.

    PubMed

    Vuiblet, V; Nguyen, T T; Wynckel, A; Fere, M; Van-Gulick, L; Untereiner, V; Birembaut, P; Rieu, P; Piot, O

    2015-11-07

    HydroxyEthyl Starch (HES) has been one of the most commonly used colloid volume expanders in intensive care units for over 50 years. The first and second generation HES, with a high molecular weight (≥200 kD) and a high degree of substitution (≥0.5), has been associated with both renal dysfunction and osmotic nephrosis-like lesions in histological studies. Recently, third generation HES (130 kD/<0.5) has also been shown to impair renal function in critically ill adult patients although tubular accumulation of HES has never been proven in the human kidney. Our objective was to demonstrate the potential of Raman micro-imaging to bring out the presence of third generation-HES in the kidney of patients having received the volume expander. Four biopsies presenting osmotic nephrosis-like lesions originated from HES-administrated patients with impaired renal function were compared with HES-negative biopsies (n = 10) by Raman microspectroscopy. The first step was dedicated to the identification of a specific vibration of HES permitting the detection of the cellular and tissue accumulation of the product. This specific vibration at 480 cm(-1) is assigned to a collective mode of the macromolecule; it is located in a spectral region with a limited contribution from biological materials. Based on this finding, HES distribution within tissue sections was investigated using Raman micro-imaging. Determination of HES positive pixels permitted us to clearly distinguish positive cases from HES-free biopsies (proportions of positive pixels from the total number of pixels: 23.48% ± 28 vs. 0.87% ± 1.2; p = 0.004). This study shows that Raman spectroscopy is a candidate technique to detect HES in kidney tissue samples currently manipulated in nephrology departments. In addition, on the clinical aspect, our approach suggests that renal impairment related to third generation HES administration is associated with osmotic nephrosis-like lesions and HES accumulation in the kidney.

  16. Accelerated detection of intracranial space-occupying lesions with CUDA based on statistical texture atlas in brain HRCT.

    PubMed

    Liu, Wei; Feng, Huanqing; Li, Chuanfu; Huang, Yufeng; Wu, Dehuang; Tong, Tong

    2009-01-01

    In this paper, we present a method that detects intracranial space-occupying lesions in two-dimensional (2D) brain high-resolution CT images. Use of statistical texture atlas technique localizes anatomy variation in the gray level distribution of brain images, and in turn, identifies the regions with lesions. The statistical texture atlas involves 147 HRCT slices of normal individuals and its construction is extremely time-consuming. To improve the performance of atlas construction, we have implemented the pixel-wise texture extraction procedure on Nvidia 8800GTX GPU with Compute Unified Device Architecture (CUDA) platform. Experimental results indicate that the extracted texture feature is distinctive and robust enough, and is suitable for detecting uniform and mixed density space-occupying lesions. In addition, a significant speedup against straight forward CPU version was achieved with CUDA.

  17. Detection of Loxosceles venom in lesional hair shafts and skin: application of a specific immunoassay to identify dermonecrotic arachnidism.

    PubMed

    Miller, M J; Gomez, H F; Snider, R J; Stephens, E L; Czop, R M; Warren, J S

    2000-09-01

    Loxosceles spiders, of which the brown recluse is the best known, are indigenous to southcentral and southwestern regions of the United States. Loxosceles spider envenomation frequently results in painful, centrally necrotic, erythematous skin lesions that evolve over 24 to 48 hours and may take several weeks to completely heal. The diagnosis of loxoscelism is typically is based on the presence of the characteristic dermal lesion, because no definitive clinical diagnostic assay exists, and the spider is generally not available for identification. We used a rapid Loxosceles-specific enzyme immunoassay to detect spider venom in a dermal biopsy and hairs plucked from a suspicious skin lesion on the lower extremity of a 52-year-old man. This report indicates that in using a novel Loxosceles-specific immunoassay, venom can be detected in dermonecrotic skin and hair specimens for up to 4 days after envenomation.

  18. Development and evaluation of an automatic acne lesion detection program using digital image processing.

    PubMed

    Min, Seonguk; Kong, Hyoun-joong; Yoon, Chiyul; Kim, Hee Chan; Suh, Dae Hun

    2013-02-01

    Existing acne grading methods, which depend on overall impression, require a long training period and there is a high degree of variability among raters, including trained dermatologists. The use of lesion count provides fair reproducibility but the method is time consuming. New technologies in photographic equipment and software allow solutions to the problem of acne evaluation. This study was conducted to develop the automatic acne lesion program and evaluation of its usefulness. We made the conditions to optimize characterization of acne lesions and developed the counting program. Twenty-five volunteers with acne lesions were enrolled. Automated lesion counting for five subtypes of acne (papule, nodule, pustule, whitehead comedone, and blackhead comedone) was performed with image processing. The usefulness of the automatic lesion count program was assessed by a comparison with manual counting performed by an expert dermatologist. In a comparison with manual counting performed by an expert dermatologist, the sensitivity and positive predictive value of the lesion-counting program was greater than 70% for papules, nodules, pustules, and whitehead comedo. In a comparison with manual counting, findings with the use of the lesion-counting program were well correlated for papules, nodules, pustules, and whitehead comedo (r > 0.9). Automatic lesion-counting program can be a useful tool for acne severity evaluation. © 2012 John Wiley & Sons A/S.

  19. The effect of expert knowledge on medical search: medical experts have specialized abilities for detecting serious lesions.

    PubMed

    Nakashima, Ryoichi; Watanabe, Chisaki; Maeda, Eriko; Yoshikawa, Takeharu; Matsuda, Izuru; Miki, Soichiro; Yokosawa, Kazuhiko

    2015-09-01

    How does domain-specific knowledge influence the experts' performance in their domain of expertise? Specifically, can visual search experts find, with uniform efficiency, any type of target in their domain of expertise? We examined whether acquired knowledge of target importance influences an expert's visual search performance. In some professional searches (e.g., medical screenings), certain targets are rare; one aim of this study was to examine the extent to which experts miss such targets in their searches. In one experiment, radiologists (medical experts) engaged in a medical lesion search task in which both the importance (i.e., seriousness/gravity) and the prevalence of targets varied. Results showed decreased target detection rates in the low prevalence conditions (i.e., the prevalence effect). Also, experts were better at detecting important (versus unimportant) lesions. Results of an experiment using novices ruled out the possibility that decreased performance with unimportant targets was due to low target noticeability/visibility. Overall, the findings suggest that radiologists do not have a generalized ability to detect any type of lesion; instead, they have acquired a specialized ability to detect only those important lesions relevant for effective medical practices.

  20. Detection of copy number variations in melanocytic lesions utilising array based comparative genomic hybridisation.

    PubMed

    Mesbah Ardakani, Nima; Thomas, Carla; Robinson, Cleo; Mina, Kym; Harvey, Nathan Tobias; Amanuel, Benhur; Wood, Benjamin Andrew

    2017-04-01

    Distinction between melanocytic naevi and melanoma occasionally poses a diagnostic challenge in ambiguous cases showing overlapping histological features. Melanomas are characterised by the presence of multiple genomic copy number variants (CNVs), while this is not a feature of naevi. We assessed the feasibility and utility of array-based comparative genomic hybridisation (aCGH) to assess CNVs in melanocytic lesions. DNA was extracted from formalin fixed, paraffin embedded (FFPE) sections of unambiguous naevi (n=19) and melanomas (n=19). The test DNA and gender mismatched human reference DNA were differentially labelled with fluorophores. Equal quantities of the two DNA samples were mixed and co-hybridised to a SurePrint G3 Human CGH 8x60K array, and digitally scanned to capture and quantify the relative fluorescence intensities. The ratio of the fluorescence intensities was analysed by Cytogenomics software (Agilent). Frequent large CNVs were identified in 94.7% of melanoma samples, including losses of 9p (73.6%), 9q (52.6%), 10q (36.8%), 11q (36.8%), 3p (21%), and 10p (21%), and gains of 6p (42.1%), 7p (42.1%), 1q (36.8%), 8q (31.5%) and 20q (21%). Only one naevus showed two large copy number changes. Overall aCGH showed a specificity and sensitivity of 94.7% in separating naevi from melanomas. Based on our results, aCGH can be successfully used to analyse CNVs of melanocytic lesions utilising FFPE derived biopsy samples, providing a potentially useful adjunctive test for the classification of diagnostically challenging melanocytic proliferations. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  1. FISH analysis of intrapulmonary malignant mesothelioma without a clinically detectable primary pleural lesion: an autopsy case.

    PubMed

    Hasegawa, Mizue; Sakai, Fumikazu; Sato, Akitoshi; Tsubomizu, Sayuri; Arimura, Ken; Katsura, Hideki; Koh, Eitetsu; Sekine, Yasuo; Wu, Di; Hiroshima, Kenzo

    2014-12-01

    Patients with malignant mesothelioma typically present with a pleural effusion or pleural thickening and masses. A rare autopsy case of mesothelioma presenting with multiple bilateral lung nodules without clinically detectable pleural lesions is presented. A definitive diagnosis of the video-assisted thoracic surgery specimen could not be made, though a pattern of fibrosis mimicking organizing pneumonia was identified. Despite corticosteroid therapy, follow-up chest computed tomography showed enlargement of multiple nodules accompanied by the appearance of pleural thickening and effusions. The patient died of respiratory failure 11 months after initial presentation. Autopsy and retrospective analysis of the video-assisted thoracic surgery specimen using a p16 fluorescence in situ hybridization assay showed p16 homozygous deletion. The final diagnosis was sarcomatoid mesothelioma, and the lung nodules were intrapulmonary metastases from a clinically undetectable pleural sarcomatoid mesothelioma. It is important both to consider the possibility of mesothelioma with unusual clinical, radiological and pathological presentations and to remember that p16 fluorescence in situ hybridization analysis can play an important role in the diagnosis of mesothelioma.

  2. The performance of multimodal hyperspectral spectroscopy in the detection of precancerous cervical lesions

    NASA Astrophysics Data System (ADS)

    Trahmono; Lusiana, N.; Indarti, J.

    2017-08-01

    The aim of this study was to compare the performance of multimodal hyperspectral spectroscopy (MHS), which combines fluorescence and reflectance spectroscopy, with that of conventional laboratory-based screening tests, such as the Papanicolaou (Pap) smear test and human papilloma virus (HPV) DNA test, for detecting precancerous lesions of the cervix. The study utilized a cross-sectional design, and the kappa test was used in the analytical assessment. MHS scans were obtained from a sample of 70 consecutive patients, followed by sample collection for Pap and HPV DNA analysis and colposcopy referral, if indicated. Of the 70 patients evaluated, the results of cervical spectroscopy were normal in 38 (54.3%) patients, and they were abnormal in 32 (45.7%) patients. Based on the cytology results, 45 (64.3%) samples were normal, and 25 (35.7%) samples were abnormal. According to the results of the HPV DNA test, 47 (67.14%) samples were normal, and 17 (24.28%) samples were abnormal. Based on the results of the kappa test, the agreement between MHS and cytology was 0.793 (p < 0.001). The agreement between MHS and the HPV DNA test was 0.195 (p = 0.086), and the agreement between MHS and colposcopy was 0.479 (p < 0.001).

  3. Detection of benign proliferative lesions on vocal cords with voice handicap index.

    PubMed

    Huang, Xuekun; Zhang, Gehua; Liu, Xiujin; Wang, Tao; Zhu, Ling

    2012-10-01

    The aim of this study was to investigate the significance and practical applicability of the voice handicap index (VHI) in the diagnosis of benign proliferative lesions of the vocal cords (BLVCs). The detection of VHI included the calculation of functional (F), physical (P) and emotional (E) domains, and the score of each domain and total score (TVH). The VHI was scored in patients with BLVCs and healthy controls. Eighty-four patients with BLVCs and 27 healthy controls were enrolled in the present study. The F, P, E and TVH scores were 10.40±7.84, 19.88±8.81, 9.39±8.49 and 39.37±21.83, respectively, in the BLVC group and 0.78±0.97, 0.85±1.06, 0.26±0.72 and 1.89±2.31, respectively, in the control group. A significant difference was found between the two groups (P<0. 01). The daily duration of speech and course of BLVCs did not correlate with the VHI score in BLVC patients (P>0.05). There was no marked difference in the VHI score between voice-consuming and non-voice consuming occupations (P>0.05) or between males and females (P>0.05). In BLVC patients, VHI may subjectively express the voice handicap, while daily duration of speech, course of BLVC, occupation and gender have no impact on VHI.

  4. Consortium for Molecular Characterization of Screen-Detected Lesions Created: Eight Grants Awarded | Division of Cancer Prevention

    Cancer.gov

    The NCI has awarded eight grants to create the Consortium for Molecular Characterization of Screen-Detected Lesions. The consortium has seven molecular characterization laboratories (MCLs) and a coordinating center, and is supported by the Division of Cancer Prevention and the Division of Cancer Biology. | 7 laboratories and a coordinating center focused on identifying screening-detected pre-cancers and early cancers, including within the tumor microenvironment.

  5. Stretchable Electrochemical Impedance Sensors for Intravascular Detection of Lipid-Rich Lesions in New Zealand White Rabbits

    PubMed Central

    Cao, Hung; Yu, Fei; Zhao, Yu; Scianmarello, Nick; Lee, Juhyun; Dai, Wangde; Jen, Nelson; Beebe, Tyler; Li, Rongsong; Ebrahimi, Ramin; Chang, Donald S.; Mody, Freny V.; Pacella, John; Tai, Yu-Chong; Hsiai, Tzung

    2014-01-01

    Flexible electronics have enabled catheter-based intravascular sensing. However, real-time interrogation of unstable plaque remains an unmet clinical challenge. Here, we demonstrate the feasibility of stretchable electrochemical impedance spectroscopy (EIS) sensors for endoluminal investigations in New Zealand White (NZW) rabbits on diet-induced hyperlipidemia. A parylene C (PAC)-based EIS sensor mounted on the surface of an inflatable silicone balloon affixed to the tip of an interrogating catheter was deployed 1) on the explants of NZW rabbit aorta for detection of lipid-rich atherosclerotic lesions, and 2) on live animals for demonstration of balloon inflation and EIS measurements. An input peak-to-peak AC voltage of 10 mV and sweeping-frequency from 300 kHz to 100 Hz were delivered to the endoluminal sites. Balloon inflation allowed EIS sensors to be in contact with endoluminal surface. In the oxidized low-density-lipoprotein (oxLDL)-rich lesions from explants of fat-fed rabbits, impedance magnitude increased significantly by 1.5-fold across the entire frequency band, and phase shifted ~5 degrees at frequencies below 10 kHz. In the lesion-free sites of the normal diet-fed rabbits, impedance magnitude increased by 1.2-fold and phase shifted ~5 degrees at frequencies above 30 kHz. Thus, we demonstrate the feasibility of stretchable intravascular EIS sensors for identification of lipid rich lesions, with a translational implication for detecting unstable lesions. PMID:24333932

  6. Chromosomal lesions and uniparental disomy detected by SNP arrays in MDS, MDS/MPD, and MDS-derived AML

    PubMed Central

    Gondek, Lukasz P.; Tiu, Ramon; O'Keefe, Christine L.; Sekeres, Mikkael A.; Theil, Karl S.

    2008-01-01

    Using metaphase cytogenetics (MC), chromosomal abnormalities are found in only a proportion of patients with myelodysplastic syndrome (MDS). We hypothesized that with new precise methods more cryptic karyotypic lesions can be uncovered that may show important clinical implications. We have applied 250K single nucleotide polymorphisms (SNP) arrays (SNP-A) to study chromosomal lesions in samples from 174 patients (94 MDS, 33 secondary acute myeloid leukemia [sAML], and 47 myelodysplastic/myeloproliferative disease [MDS/MPD]) and 76 controls. Using SNP-A, aberrations were found in around three-fourths of MDS, MDS/MPD, and sAML (vs 59%, 37%, 53% by MC; in 8% of patients MC was unsuccessful). Previously unrecognized lesions were detected in patients with normal MC and in those with known lesions. Moreover, segmental uniparental disomy (UPD) was found in 20% of MDS, 23% of sAML, and 35% of MDS/MPD patients, a lesion resulting in copy-neutral loss of heterozygosity undetectable by MC. The potential clinical significance of abnormalities detected by SNP-A, but not seen on MC, was demonstrated by their impact on overall survival. UPD involving chromosomes frequently affected by deletions may have prognostic implications similar to the deletions visible by MC. SNP-A–based karyotyping shows superior resolution for chromosomal defects, including UPD. This technique further complements MC to improve clinical prognosis and targeted therapies. PMID:17954704

  7. Reliability of toluidine blue vital staining in detection of potentially malignant oral lesions--time to reconsider.

    PubMed

    Upadhyay, Juhi; Rao, Nirmala N; Upadhyay, Ram B; Agarwal, Pankaj

    2011-01-01

    Being simple and inexpensive toluidine blue has been in use for more than two decades for the detection of potentially malignant oral lesions (PMOL's) and malignant lesions. Although there has been concensus that staining often assists in the identification of these lesions, results have been diverse. In most studies false negative were not recorded as biopsies of lesions that did not retain toluidine blue were not performed. Thus the present study attempted to evaluate the efficacy of toluidine blue vital dye for detection of PMOL's. The study included 47 biopsies (TBP:35 and TBN:12), of which 23 cases were confirmed as dysplastic (TBP=17 and TBN=6), 7 as hyperkeratosis (TBP=4 and TBN=3), 8 as epithelial hyperplasia (TBP=6 and TBN=3) and 5 as other benign lesions (TBP=4 and TBN=1). The validity test revealed a senstivity of 73.9% and specificity of 30%. The positive predictive value was 54.8% and negative predictive value of 50%. The study intends to highlight the false negative result (26.1%) which was mainly attributed to mild dysplasia and the false positive (32.6%) which included hyperkeratosis, hyperplasia, lichen planus and traumatic ulcer. The study concludes that toluidine blue staining should not blindly direct the clinician's opinion, and strongly discourages the use of toludine blue as a screening test and the results should be interpreted with caution.

  8. Effects of striatal lesions on components of choice: Reward discrimination, preference, and relative valuation.

    PubMed

    Ricker, Joshua M; Kopchock, Richard J; Drown, Rachel M; Cromwell, Howard C

    2016-12-15

    The striatum is a key structure involved in reward processing and choice. Recently, we have developed a paradigm to explore how components of reward processing work together or independently during choice behavior. These components include reward discrimination, preference and relative valuation, and the goal of the present study was to determine how the striatum is involved in these dissociable components during this novel free choice paradigm. We tested choice utilizing two different outcome series with one being a more straightforward single-option discrimination anchored by a 0 reward outcome, and the other as a multi-option outcome discrimination of greater difficulty. We compared the free choice reward task to a sequential reward task and an extinction task. Striatal lesions impaired responding only in the free choice version with alterations in both appetitive and consummatory measures. Ventral striatal lesions had greater impact altering discrimination, preference and relative valuation in both the single and multi-option week studies. A major factor involved in these deficits was a significant aversion to the multi-option that contained a larger outcome option but with a longer delay to reward. Dorsal striatal lesions caused less impairment even leading to enhanced choice behavior compared to control animals during the more difficult multi-option free choice series. Overall, the results suggest that the context of action is crucial when linking striatal function to choice behavior and its diverse components. The implications include the idea that striatal involvement in decision-making is increased when responses are self-paced and diverse in a more naturalistic environment. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Dendritic cell subsets and immunological milieu in inflammatory human papilloma virus-related skin lesions.

    PubMed

    Nakayama, Yumi; Asagoe, Kenji; Yamauchi, Akiko; Yamamoto, Takenobu; Shirafuji, Yoshinori; Morizane, Shin; Nakanishi, Gen; Iwatsuki, Keiji

    2011-09-01

    Human papilloma virus (HPV)-related warts persist, evading host immune surveillance, but sometimes disappear with inflammation. To elucidate the immune evasion mechanisms of HPV, we have examined the density, dynamics, and subsets of dendritic cell (DC) types in non-inflammatory or inflammatory HPV-related skin lesions such as warts and Bowen's disease (HPV-Bowen), and compared the epidermal expression levels of macrophage inflammatory protein (MIP)-3α and E-cadherin. The expression of various DC markers, MIP-3α, and E-cadherin in the tissue samples obtained from patients with warts, HPV-Bowen and HPV-unrelated skin diseases was evaluated by immunohistochemistry. MIP-3α gene expression levels were examined in warts and HPV-Bowen by in situ hybridization (ISH) and real-time quantitative polymerase chain reaction (RT-qPCR). The numbers of Langerhans cells (LCs) and the expression levels of MIP-3α and E-cadherin were decreased in non-inflammatory warts and HPV-Bowen, as compared with normal skin. Both epidermal LCs and MIP-3α expression reappeared in inflammatory warts, associated with dermal infiltrates composed of many cytotoxic T cells and various subsets of DCs, while cellular infiltrates in HPV-Bowen contained many B cells and plasma cells with sparse infiltration of DCs. The upregulation of MIP-3α gene expression was confirmed in the inflammatory warts and HPV-Bowen by ISH and RT-qPCR. The depletion of LCs in the non-inflammatory warts and HPV-Bowen is associated with a down-regulation of expression levels of MIP-3α and E-cadherin in the lesional keratinocytes. MIP-3α expression is upregulated in lesional keratinocytes of inflammatory warts, with the subsequent recruitment of various DC subsets and cytotoxic T cells, whereas plasma cell-rich infiltration was induced in HPV-Bowen. Copyright © 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  10. Tissue resonance interaction accurately detects colon lesions: A double-blind pilot study

    PubMed Central

    Dore, Maria P; Tufano, Marcello O; Pes, Giovanni M; Cuccu, Marianna; Farina, Valentina; Manca, Alessandra; Graham, David Y

    2015-01-01

    AIM: To investigated the performance of the tissue resonance interaction method (TRIM) for the non-invasive detection of colon lesions. METHODS: We performed a prospective single-center blinded pilot study of consecutive adults undergoing colonoscopy at the University Hospital in Sassari, Italy. Before patients underwent colonoscopy, they were examined by the TRIMprobe which detects differences in electromagnetic properties between pathological and normal tissues. All patients had completed the polyethylene glycol-containing bowel prep for the colonoscopy procedure before being screened. During the procedure the subjects remained fully dressed. A hand-held probe was moved over the abdomen and variations in electromagnetic signals were recorded for 3 spectral lines (462-465 MHz, 930 MHz, and 1395 MHz). A single investigator, blind to any clinical information, performed the test using the TRIMprob system. Abnormal signals were identified and recorded as malignant or benign (adenoma or hyperplastic polyps). Findings were compared with those from colonoscopy with histologic confirmation. Statistical analysis was performed by χ2 test. RESULTS: A total of 305 consecutive patients fulfilling the inclusion criteria were enrolled over a period of 12 months. The most frequent indication for colonoscopy was abdominal pain (33%). The TRIMprob was well accepted by all patients; none spontaneously complained about the procedure, and no adverse effects were observed. TRIM proved inaccurate for polyp detection in patients with inflammatory bowel disease (IBD) and they were excluded leaving 281 subjects (mean age 59 ± 13 years; 107 males). The TRIM detected and accurately characterized all 12 adenocarcinomas and 135/137 polyps (98.5%) including 64 adenomatous (100%) found. The method identified cancers and polyps with 98.7% sensitivity, 96.2% specificity, and 97.5% diagnostic accuracy, compared to colonoscopy and histology analyses. The positive predictive value was 96.7% and the

  11. [Amyloid beta-related angiitis: brain lesions showing leptomeningeal gadolinium enhancement on MRI and characteristic surgical pathologic features].

    PubMed

    Koike, Yuka; Ouchi, Haruka; Sato, Tomoe; Shimbo, Junsuke; Sato, Aki; Sasaki, Osamu; Shibuya, Hiroyuki; Okamoto, Kouichirou; Kakita, Akiyoshi; Igarashi, Shuichi

    2013-06-01

    Amyloid-β-related angiitis (ABRA) of the CNS occurs in association with vasculitis of small-and medium-sized leptomeningeal arteries. Here, we describe the clinicopathological features of a 76-year-old man with ABRA. The patient suffered progressive truncal oscillation, aphasia, and recent memory disturbance with a subacute disease onset. His cerebrospinal fluid showed a mild increase in protein levels (101 mg/dL) and pleocytosis (8/mm(3)). High-intensity brain lesion were detected on T(2)-weighted and FLAIR MRI scans, and prominent spread of gadolinium enhancement spreading was observed through the sulci of the left occipital and temporal lobes and left cerebellar hemisphere. A biopsy of the left temporal lesion showed a granulomatous and angiodestructive inflammation with infiltration of many CD4(+) T-lymphocytes and multinucleated giant cells and with fibrinoid necrosis of the arterial walls in the subarachnoid space. Immunolabeling for Aβ(1-40) revealed the abundant deposition of this protein in the affected arteries. On the basic of the diagnosis of ABRA, immunosuppressive therapy was conducted, and it ameliorated the clinical course.

  12. Detection of atherosclerotic lesions and intimal macrophages using CD36-targeted nanovesicles

    USDA-ARS?s Scientific Manuscript database

    Current approaches to the diagnosis and therapy of atherosclerosis cannot target to lesion-determinant cells in the artery wall. Intimal macrophage infiltration promotes atherosclerotic lesion development by facilitating the accumulation of oxidized low-density lipoproteins (oxLDL) and increasing in...

  13. Optical Coherence Tomography Based Observation of Natural History of Drusenoid Lesion in Eyes with Dry Age-Related Macular Degeneration

    PubMed Central

    Ouyang, Yanling; Heussen, Florian M.; Hariri, Amirhossein; Keane, Pearse A.; Sadda, Srinivas R.

    2013-01-01

    Purpose To use spectral domain optical coherence tomography (SD-OCT) to investigate risk factors predictive for development of atrophy of drusenoid lesions (drusen and drusenoid pigment epithelium detachment) in eyes with non-neovascular age-related macular degeneration (NNVAMD). Design Cohort study. Participants Forty-one eyes from 29 patients with NNVAMD. Methods Patients with NNVAMD who underwent registered SD-OCT imaging over a minimum period of six months, were reviewed. Drusenoid lesions that accompanied by new atrophy onset at 6 month or last follow up were further analyzed. Detailed lesion change was described throughout the study period. Odds ratios (OR) and risk for new local atrophy onset were calculated. Main Outcomes Measures Drusenoid lesion features and longitudinal changes in features including maximum lesion height, lesion diameter, lesion internal reflectivity, presence and extent of overlying intraretinal hyperreflective features (HRF). Subfoveal choroidal thickness and choroidal thickness measured below each lesion. Results 543 individual drusenoid lesions were identified at baseline, while 28 lesions developed during follow-up. The mean follow-up time was 21.3 ± 8.6 (range, 6-44) months. 3.2% (18/571) of drusenoid lesions progressed to atrophy within 18.3±9.5 (range: 5-28) months of initial visit. Drusenoid lesions with heterogenous internal reflectivity were significantly associated with new atrophy onset at 6 month (OR=5.614, 95% confidence interval (CI) =1.277-24.673) and new atrophy onset at last follow up (OR=7.005, CI=2.300-21.337). Lesions with presence of HRF also were significant predictors for new atrophy onset at 6 month (OR=30.161, CI=4.766-190.860) and at last follow up (OR=11.211, CI=2.513-50.019). Lesions with a baseline maximum height over 80 microns or choroidal thickness less than 135 microns showed positive association with the new atrophy onset at last follow up (OR=7.886, CI=2.105-29.538 and OR=3.796, CI=1

  14. Surgery for Hemorrhagic Choroidal Neovascular Lesions of Age-Related Macular Degeneration: Quality-of-Life Findings

    PubMed Central

    2005-01-01

    Purpose To present and compare findings from health-related quality-of-life (HRQOL) interviews conducted with patients enrolled in the SST Group B Trial evaluating surgical removal of subfoveal choroidal neovascular lesions associated with age-related macular degeneration versus observation. Design Randomized clinical trial. Participants Eligible patients had predominantly hemorrhagic subfoveal choroidal neovascular lesions (total lesion size of >3.5 disc areas, area of blood at least 50% of the lesion area, and at least 75% of blood posterior to the equator) and best-corrected visual acuity (VA) of 20/100 to <20/1600 but at least light perception in the study eye. Three hundred thirty-six patients enrolled after baseline quality-of-life interviews, 168 assigned to each of surgery or observation. Methods Clinical and HRQOL data were collected before randomization and at 6, 12, 24, 36, and 48 months after enrollment. Baseline clinical evidence was used to stratify patients as having unilateral or bilateral neovascularization at the time of randomization. The HRQOL interviews included the National Eye Institute Visual Function Questionnaire (NEI-VFQ), the 36-item Short Form Health Survey, and the Hospital Anxiety and Depression Scale. Main Outcomes Measure Two-year change in NEI-VFQ. Results At 24 months after enrollment, overall NEI-VFQ scores had a median decrease of 1 point from baseline in the observation arm (95% confidence interval [CI]: −4 to 3 points) and no change in the surgery arm (95% CI: −3 to 3 points) (P = 0.70). Changes from baseline on NEI-VFQ subscales also were similar between treatment arms. Differences in scores by unilateral or bilateral involvement seen at baseline in each treatment arm persisted throughout follow-up for most outcomes. Planned analyses stratified by VA showed trends (P = 0.17) in favor of surgery at 24 months in the patients with baseline VA greater than 20/200 for the NEI-VFQ scale (3.5-point median increase from baseline

  15. A Novel Method Based on Learning Automata for Automatic Lesion Detection in Breast Magnetic Resonance Imaging

    PubMed Central

    Salehi, Leila; Azmi, Reza

    2014-01-01

    Breast cancer continues to be a significant public health problem in the world. Early detection is the key for improving breast cancer prognosis. In this way, magnetic resonance imaging (MRI) is emerging as a powerful tool for the detection of breast cancer. Breast MRI presently has two major challenges. First, its specificity is relatively poor, and it detects many false positives (FPs). Second, the method involves acquiring several high-resolution image volumes before, during, and after the injection of a contrast agent. The large volume of data makes the task of interpretation by the radiologist both complex and time-consuming. These challenges have led to the development of the computer-aided detection systems to improve the efficiency and accuracy of the interpretation process. Detection of suspicious regions of interests (ROIs) is a critical preprocessing step in dynamic contrast-enhanced (DCE)-MRI data evaluation. In this regard, this paper introduces a new automatic method to detect the suspicious ROIs for breast DCE-MRI based on region growing. The results indicate that the proposed method is thoroughly able to identify suspicious regions (accuracy of 75.39 ± 3.37 on PIDER breast MRI dataset). Furthermore, the FP per image in this method is averagely 7.92, which shows considerable improvement comparing to other methods like ROI hunter. PMID:25298929

  16. A novel method based on learning automata for automatic lesion detection in breast magnetic resonance imaging.

    PubMed

    Salehi, Leila; Azmi, Reza

    2014-07-01

    Breast cancer continues to be a significant public health problem in the world. Early detection is the key for improving breast cancer prognosis. In this way, magnetic resonance imaging (MRI) is emerging as a powerful tool for the detection of breast cancer. Breast MRI presently has two major challenges. First, its specificity is relatively poor, and it detects many false positives (FPs). Second, the method involves acquiring several high-resolution image volumes before, during, and after the injection of a contrast agent. The large volume of data makes the task of interpretation by the radiologist both complex and time-consuming. These challenges have led to the development of the computer-aided detection systems to improve the efficiency and accuracy of the interpretation process. Detection of suspicious regions of interests (ROIs) is a critical preprocessing step in dynamic contrast-enhanced (DCE)-MRI data evaluation. In this regard, this paper introduces a new automatic method to detect the suspicious ROIs for breast DCE-MRI based on region growing. The results indicate that the proposed method is thoroughly able to identify suspicious regions (accuracy of 75.39 ± 3.37 on PIDER breast MRI dataset). Furthermore, the FP per image in this method is averagely 7.92, which shows considerable improvement comparing to other methods like ROI hunter.

  17. Detection of infarct lesions from single MRI modality using inconsistency between voxel intensity and spatial location--a 3-D automatic approach.

    PubMed

    Shen, Shan; Szameitat, André J; Sterr, Annette

    2008-07-01

    Detection of infarct lesions using traditional segmentation methods is always problematic due to intensity similarity between lesions and normal tissues, so that multispectral MRI modalities were often employed for this purpose. However, the high costs of MRI scan and the severity of patient conditions restrict the collection of multiple images. Therefore, in this paper, a new 3-D automatic lesion detection approach was proposed, which required only a single type of anatomical MRI scan. It was developed on a theory that, when lesions were present, the voxel-intensity-based segmentation and the spatial-location-based tissue distribution should be inconsistent in the regions of lesions. The degree of this inconsistency was calculated, which indicated the likelihood of tissue abnormality. Lesions were identified when the inconsistency exceeded a defined threshold. In this approach, the intensity-based segmentation was implemented by the conventional fuzzy c-mean (FCM) algorithm, while the spatial location of tissues was provided by prior tissue probability maps. The use of simulated MRI lesions allowed us to quantitatively evaluate the performance of the proposed method, as the size and location of lesions were prespecified. The results showed that our method effectively detected lesions with 40-80% signal reduction compared to normal tissues (similarity index > 0.7). The capability of the proposed method in practice was also demonstrated on real infarct lesions from 15 stroke patients, where the lesions detected were in broad agreement with true lesions. Furthermore, a comparison to a statistical segmentation approach presented in the literature suggested that our 3-D lesion detection approach was more reliable. Future work will focus on adapting the current method to multiple sclerosis lesion detection.

  18. Diagnostic performance of automated breast ultrasound as a replacement for a hand-held second-look ultrasound for breast lesions detected initially on magnetic resonance imaging.

    PubMed

    Chae, Eun Young; Shin, Hee Jung; Kim, Hyun Ji; Yoo, Hyunkyung; Baek, Seunghee; Cha, Joo Hee; Kim, Hak Hee

    2013-12-01

    To evaluate the diagnostic performance of automated breast ultrasound (ABUS) after breast magnetic resonance imaging (MRI) as a replacement for hand-held second-look ultrasound (HH-SLUS), we evaluated 58 consecutive patients with breast cancer who had additional suspicious lesions on breast MRI. All patients underwent HH-SLUS and ABUS. Three breast radiologists evaluated the detectability, location, characteristics and conspicuity of lesions on ABUS. We also evaluated inter-observer variability and compared the results with HH-SLUS results. Eighty additional suspicious lesions were identified on breast MRI. Fifteen of the 80 lesions (19%) were not detected on HH-SLUS. Eight of the 15 lesions (53%) were detected on ABUS, whereas the remaining 7 were not detected on ABUS. Among the 65 lesions detected on HH-SLUS, only 3 lesions were not detected on ABUS. The intra-class correlation coefficients for lesion location and size all exceeded 0.70, indicating high reliability. Moderate to fair agreement was found for mass shape, orientation, margin and Breast Imaging Reporting and Data System (BI-RADS) final assessment. Therefore, ABUS can reliably detect additional suspicious lesions identified on breast MRI and may help in the decision on biopsy guidance method (US vs. MRI) as a replacement tool for HH-SLUS. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  19. The Association of Lesion Location and Sleep Related Breathing Disorder in Patients with Acute Ischemic Stroke

    PubMed Central

    Teuber, Anja; Wersching, Heike; Young, Peter; Dittrich, Ralf; Ritter, Martin; Dziewas, Rainer; Minnerup, Jens

    2017-01-01

    Background and aims Sleep related breathing disorders (SRBD) are common in patients with ischemic stroke and are associated with poor outcome. SRBD after stroke were assumed to be a direct consequence of injury of specific central nervous system structures. However, whether specific locations of ischemic infarcts cause SRBD is yet unknown. We therefore investigated the association of ischemic lesion location with SRBD. Methods Patients with acute ischemic stroke treated on our stroke unit were included in a prospective observational study. All patients underwent magnetic resonance imaging (MRI) and polygraphy in the acute phase after stroke. SRBD was defined by an apnea—hypopnea index (AHI) ≥10. MRI were evaluated using standardized maps to depict voxel-wise probability distribution of infarction for patients with and without SRBD. Groups were compared using logistic regression analysis. Results Of 142 patients included, 86 (59%) had a SRBD. Age, body mass index and prevalence of arterial hypertension were significantly higher in patients with SRBD. There was no statistically significant association between any lesion location and SRBD. Conclusion We found no association of lesion location and SRBD in stroke patients, whereas established risk factors for SRBD, known from general population, were significantly associated with SRBD. Given the high prevalence of SRBD in stroke patients, these findings suggest that cerebral ischemia facilitates the occurrence of SRBD in patients with pre-existing risk factors rather than causing it by damaging specific central nervous system structures. Our findings can be used to identify stroke patients who might benefit from polygraphy screening. PMID:28135315

  20. Automatic segmentation of white matter lesions on magnetic resonance images of the brain by using an outlier detection strategy.

    PubMed

    Wang, Rui; Li, Chao; Wang, Jie; Wei, Xiaoer; Li, Yuehua; Hui, Chun; Zhu, Yuemin; Zhang, Su

    2014-12-01

    White matter lesions (WMLs) are commonly observed on the magnetic resonance (MR) images of normal elderly in association with vascular risk factors, such as hypertension or stroke. An accurate WML detection provides significant information for disease tracking, therapy evaluation, and normal aging research. In this article, we present an unsupervised WML segmentation method that uses Gaussian mixture model to describe the intensity distribution of the normal brain tissues and detects the WMLs as outliers to the normal brain tissue model based on extreme value theory. The detection of WMLs is performed by comparing the probability distribution function of a one-sided normal distribution and a Gumbel distribution, which is a specific extreme value distribution. The performance of the automatic segmentation is validated on synthetic and clinical MR images with regard to different imaging sequences and lesion loads. Results indicate that the segmentation method has a favorable accuracy competitive with other state-of-the-art WML segmentation methods.

  1. Perirhinal Cortex Lesions in Rats: Novelty Detection and Sensitivity to Interference

    PubMed Central

    2015-01-01

    Rats with perirhinal cortex lesions received multiple object recognition trials within a continuous session to examine whether they show false memories. Experiment 1 focused on exploration patterns during the first object recognition test postsurgery, in which each trial contained 1 novel and 1 familiar object. The perirhinal cortex lesions reduced time spent exploring novel objects, but did not affect overall time spent exploring the test objects (novel plus familiar). Replications with subsequent cohorts of rats (Experiments 2, 3, 4.1) repeated this pattern of results. When all recognition memory data were combined (Experiments 1–4), giving totals of 44 perirhinal lesion rats and 40 surgical sham controls, the perirhinal cortex lesions caused a marginal reduction in total exploration time. That decrease in time with novel objects was often compensated by increased exploration of familiar objects. Experiment 4 also assessed the impact of proactive interference on recognition memory. Evidence emerged that prior object experience could additionally impair recognition performance in rats with perirhinal cortex lesions. Experiment 5 examined exploration levels when rats were just given pairs of novel objects to explore. Despite their perirhinal cortex lesions, exploration levels were comparable with those of control rats. While the results of Experiment 4 support the notion that perirhinal lesions can increase sensitivity to proactive interference, the overall findings question whether rats lacking a perirhinal cortex typically behave as if novel objects are familiar, that is, show false recognition. Rather, the rats retain a signal of novelty but struggle to discriminate the identity of that signal. PMID:26030425

  2. Functional activation independently contributes to naming ability and relates to lesion site in post-stroke aphasia.

    PubMed

    Skipper-Kallal, Laura M; Lacey, Elizabeth H; Xing, Shihui; Turkeltaub, Peter E

    2017-04-01

    Language network reorganization in aphasia may depend on the degree of damage in critical language areas, making it difficult to determine how reorganization impacts performance. Prior studies on remapping of function in aphasia have not accounted for the location of the lesion relative to critical language areas. They rectified this problem by using a multimodal approach, combining multivariate lesion-symptom mapping and fMRI in chronic aphasia to understand the independent contributions to naming performance of the lesion and the activity in both hemispheres. Activity was examined during two stages of naming: covert retrieval, and overt articulation. Regions of interest were drawn based on over- and under-activation, and in areas where activity had a bivariate relationship with naming. Regressions then tested whether activation of these regions predicted naming ability, while controlling for lesion size and damage in critical left hemisphere naming areas, as determined by lesion-symptom mapping. Engagement of the right superior temporal sulcus (STS) and disengagement of the left dorsal pars opercularis (dPOp) during overt naming was associated with better than predicted naming performance. Lesions in the left STS prevented right STS engagement and resulted in persistent left dPOp activation. In summary, changes in activity during overt articulation independently relate to naming outcomes, controlling for stroke severity. Successful remapping relates to network disruptions that depend on the location of the lesion in the left hemisphere. Hum Brain Mapp 38:2051-2066, 2017. © 2017 Wiley Periodicals, Inc.

  3. A simulator for evaluating methods for the detection of lesion-deficit associations

    NASA Technical Reports Server (NTRS)

    Megalooikonomou, V.; Davatzikos, C.; Herskovits, E. H.

    2000-01-01

    Although much has been learned about the functional organization of the human brain through lesion-deficit analysis, the variety of statistical and image-processing methods developed for this purpose precludes a closed-form analysis of the statistical power of these systems. Therefore, we developed a lesion-deficit simulator (LDS), which generates artificial subjects, each of which consists of a set of functional deficits, and a brain image with lesions; the deficits and lesions conform to predefined distributions. We used probability distributions to model the number, sizes, and spatial distribution of lesions, to model the structure-function associations, and to model registration error. We used the LDS to evaluate, as examples, the effects of the complexities and strengths of lesion-deficit associations, and of registration error, on the power of lesion-deficit analysis. We measured the numbers of recovered associations from these simulated data, as a function of the number of subjects analyzed, the strengths and number of associations in the statistical model, the number of structures associated with a particular function, and the prior probabilities of structures being abnormal. The number of subjects required to recover the simulated lesion-deficit associations was found to have an inverse relationship to the strength of associations, and to the smallest probability in the structure-function model. The number of structures associated with a particular function (i.e., the complexity of associations) had a much greater effect on the performance of the analysis method than did the total number of associations. We also found that registration error of 5 mm or less reduces the number of associations discovered by approximately 13% compared to perfect registration. The LDS provides a flexible framework for evaluating many aspects of lesion-deficit analysis.

  4. A simulator for evaluating methods for the detection of lesion-deficit associations

    NASA Technical Reports Server (NTRS)

    Megalooikonomou, V.; Davatzikos, C.; Herskovits, E. H.

    2000-01-01

    Although much has been learned about the functional organization of the human brain through lesion-deficit analysis, the variety of statistical and image-processing methods developed for this purpose precludes a closed-form analysis of the statistical power of these systems. Therefore, we developed a lesion-deficit simulator (LDS), which generates artificial subjects, each of which consists of a set of functional deficits, and a brain image with lesions; the deficits and lesions conform to predefined distributions. We used probability distributions to model the number, sizes, and spatial distribution of lesions, to model the structure-function associations, and to model registration error. We used the LDS to evaluate, as examples, the effects of the complexities and strengths of lesion-deficit associations, and of registration error, on the power of lesion-deficit analysis. We measured the numbers of recovered associations from these simulated data, as a function of the number of subjects analyzed, the strengths and number of associations in the statistical model, the number of structures associated with a particular function, and the prior probabilities of structures being abnormal. The number of subjects required to recover the simulated lesion-deficit associations was found to have an inverse relationship to the strength of associations, and to the smallest probability in the structure-function model. The number of structures associated with a particular function (i.e., the complexity of associations) had a much greater effect on the performance of the analysis method than did the total number of associations. We also found that registration error of 5 mm or less reduces the number of associations discovered by approximately 13% compared to perfect registration. The LDS provides a flexible framework for evaluating many aspects of lesion-deficit analysis.

  5. Channeling Nanoparticles for Detection and Targeted Treatment of Breast Cancerous Lesions

    DTIC Science & Technology

    2011-10-01

    have also confirmed that non-neoplastic breast epithelial MCF10A cells display basal polarity on filters. This represents a simplified system to study ...is to provide a model to study the use of fluorescent magnetic nano or submicron particles for future detection and treatment applications. In the...PEGylation was successful as indicated by an observed size increase for the PEGylated SMPs relative to the size of the stock SMPs. Zeta potential

  6. Novel method for the detection of necrotic lesions in human cancers

    SciTech Connect

    Epstein, A.L.; Chen, F.M.; Taylor, C.R.

    1988-10-15

    Data are presented in support of the hypothesis that malignant tumors, containing abnormally permeable, degenerating cells, can be selectively detected using monoclonal antibodies to intracellular antigens. Biodistribution, imaging, and autoradiographic studies were performed in nude mice transplanted with four different human tumor cell lines to demonstrate the binding of radiolabeled antinuclear monoclonal antibodies within bulky tumors containing necrotic lesions. For these studies, two monoclonal antibodies, designated TNT-1 (IgG2a) and TNT-2 (IgM) were chosen since they were found to bind to abundant nuclear antigens which are retained in permeable, dying cells. F(ab')2 fragments prepared by pepsin digestion were radiolabeled with iodine-125 or iodine-131 by the iodogen method for i.v. administration. Biodistribution studies in nontumor-bearing BALB/c mice at various time intervals revealed normal patterns of antibody excretion with no accumulation of antibody in healthy organs. In contrast, biodistribution studies performed on Day 3 in tumor-bearing nude mice showed high tumor to organ ratios in those animals bearing necrotic tumors. Necrotic regions dissected at necropsy gave tumor to blood ratios as high as 131:1. Transplants having little demonstrable necrosis were found to have low tumor to blood ratios (0.4:1). Sequential imaging studies confirmed the high tumor-to-organ ratios and showed positive tumor imaging as early as 4 h. Autoradiographic studies of excised tumors showed the presence of label selectively in necrotic areas with preferential labeling over the nuclei of degenerating cells. Because of the universal presence of these nuclear antigens and the known prevalence of necrosis in tumors, this approach may be of value for the imaging and treatment of a wide variety of cancers in humans.

  7. Fusion of classifiers for REIS-based detection of suspicious breast lesions

    NASA Astrophysics Data System (ADS)

    Lederman, Dror; Wang, Xingwei; Zheng, Bin; Sumkin, Jules H.; Tublin, Mitchell; Gur, David

    2011-03-01

    After developing a multi-probe resonance-frequency electrical impedance spectroscopy (REIS) system aimed at detecting women with breast abnormalities that may indicate a developing breast cancer, we have been conducting a prospective clinical study to explore the feasibility of applying this REIS system to classify younger women (< 50 years old) into two groups of "higher-than-average risk" and "average risk" of having or developing breast cancer. The system comprises one central probe placed in contact with the nipple, and six additional probes uniformly distributed along an outside circle to be placed in contact with six points on the outer breast skin surface. In this preliminary study, we selected an initial set of 174 examinations on participants that have completed REIS examinations and have clinical status verification. Among these, 66 examinations were recommended for biopsy due to findings of a highly suspicious breast lesion ("positives"), and 108 were determined as negative during imaging based procedures ("negatives"). A set of REIS-based features, extracted using a mirror-matched approach, was computed and fed into five machine learning classifiers. A genetic algorithm was used to select an optimal subset of features for each of the five classifiers. Three fusion rules, namely sum rule, weighted sum rule and weighted median rule, were used to combine the results of the classifiers. Performance evaluation was performed using a leave-one-case-out cross-validation method. The results indicated that REIS may provide a new technology to identify younger women with higher than average risk of having or developing breast cancer. Furthermore, it was shown that fusion rule, such as a weighted median fusion rule and a weighted sum fusion rule may improve performance as compared with the highest performing single classifier.

  8. Lesion complexity drives age related cancer susceptibility in human mammary epithelial cells

    PubMed Central

    Sridharan, Deepa M.; Enerio, Shiena; LaBarge, Mark A.; Stampfer, Martha M.; Pluth, Janice M.

    2017-01-01

    Exposures to various DNA damaging agents can deregulate a wide array of critical mechanisms that maintain genome integrity. It is unclear how these processes are impacted by one's age at the time of exposure and the complexity of the DNA lesion. To clarify this, we employed radiation as a tool to generate simple and complex lesions in normal primary human mammary epithelial cells derived from women of various ages. We hypothesized that genomic instability in the progeny of older cells exposed to complex damages will be exacerbated by age-associated deterioration in function and accentuate age-related cancer predisposition. Centrosome aberrations and changes in stem cell numbers were examined to assess cancer susceptibility. Our data show that the frequency of centrosome aberrations proportionately increases with age following complex damage causing exposures. However, a dose-dependent increase in stem cell numbers was independent of both age and the nature of the insult. Phospho-protein signatures provide mechanistic clues to signaling networks implicated in these effects. Together these studies suggest that complex damage can threaten the genome stability of the stem cell population in older people. Propagation of this instability is subject to influence by the microenvironment and will ultimately define cancer risk in the older population. PMID:28245431

  9. A grasp-related deficit in tactile discrimination following dorsal column lesion in the rat.

    PubMed

    Ballermann, M; McKenna, J; Whishaw, I Q

    2001-01-15

    The dorsal columns of the spinal cord are a major source of haptic (sense of active touch) and proprioceptive input to the brainstem and sensory-motor cortex. Following injury in primates, there are impairments in two-point discrimination, direction of movement across the skin, and frequency of vibration, and qualitative control of the digits, but simple spatial discriminations recover. In the rat there are qualitative deficits in paw control in skilled reaching, but no sensory deficits have been reported. Because recent investigations of sensory control suggest that sensory functions may be related to specific actions, the present study investigated whether the dorsal columns contribute to hapsis during food grasping in the rat. Adult female Long-Evans rats were trained to reach with a single forepaw for a piece of uncooked pasta or for equivalent sized but tactually different nonfood items. One group was given lesions of the dorsal column ipsilateral to their preferred paw, while the second group served as a control. Postlesion, both groups were tested for skilled reaching success and force application as well as adhesive dot removal and forepaw placing. Performance levels on these tests were normal. Nevertheless, the rats with dorsal column lesions were unable to discriminate a food item from a tactually distinctive nonfood item as part of the reaching act, suggesting that the dorsal columns are important for on-line tactile discriminations, or "haptic actions," which contribute to the normal performance of grasping actions.

  10. [Digestive tract hemorrhages of cirrhotic patients. Relation between hepatic insufficiency and the hemorrhagic lesion].

    PubMed

    Franco, D; Deporte, A; Darragon, T; Bismuth, H

    1975-12-06

    The cause of upper gastrointestinal bleeding was studied in 85 cirrhotic patients by emergency endoscopy. In every patient, one or several lesions were observed and the site of bleeding was ascertained in 59. The two main causes were oesophago-gastric varices (46 p.cent) and acute mucosal lesions(42 p.cent). The source of bleeding appeared to be related to the degree of liver function impairment. In patients with no or moderate liver function impariment, bleeding usually originated from varices or from drug-associated mucosal erosions. Patients with severe impairment of liver function most often bled from spontaneous acute oeso-gastro-duodenal ulcerations. These ulcerations resembled what has been described in "stress" hemorrhage. Because of the relationship between liver function and the cause of hemorrhage, mortality was lower in variceal bleeders (29 p.cent) than in patients with spontaneous ulcerations (83 p.cent). In patients with severely impaired liver function, portacaval shunt was rarely indicated since hemorrhage was generally due to acute mucosal ulcerations.

  11. Skin lesion-associated pathogens from Octopus vulgaris: first detection of Photobacterium swingsii, Lactococcus garvieae and betanodavirus.

    PubMed

    Fichi, G; Cardeti, G; Perrucci, S; Vanni, A; Cersini, A; Lenzi, C; De Wolf, T; Fronte, B; Guarducci, M; Susini, F

    2015-07-23

    The common octopus Octopus vulgaris Cuvier, 1798 is extremely important in fisheries and is a useful protein source in most Mediterranean countries. Here we investigated pathogens associated with skin lesions in 9 naturally deceased specimens that included both cultured and wild common octopus. Within 30 min after death, each octopus was stored at 4°C and microbiologically examined within 24 h. Bacterial colonies, cultured from swabs taken from the lesions, were examined using taxonomical and biochemical analyses. Vibrio alginolyticus and V. parahaemolyticus were only isolated from cultured animals. A conventional PCR targeting the 16S ribosomal RNA (rRNA) gene and sequencing were performed on 2 bacterial isolates that remained unidentified after taxonomical and biochemical analysis. The sequence results indicated that the bacteria had a 99% identity with Lactococcus garvieae and Photobacterium swingsii. L. garvieae was confirmed using a specific PCR based on the 16S-23S rRNA internal transcribed spacer region, while P. swingsii was confirmed by phylogenetic analyses. Although all animals examined were found to be infected by the protozoan species Aggregata octopiana localised in the intestines, it was also present in skin lesions of 2 of the animals. Betanodavirus was detected in both cultured and wild individuals by cell culture, PCR and electron microscopy. These findings are the first report of L. garvieae and betanodavirus from skin lesions of common octopus and the first identification of P. swingsii both in octopus skin lesions and in marine invertebrates in Italy.

  12. Detection of human papillomavirus in intraepithelial lesions and carcinoma of the cervix uteri in southern Thai women.

    PubMed

    Tungsinmunkong, Kobkul; Suwiwat, Supaporn; Sriplung, Hutcha

    2006-01-01

    To evaluate the prevalence of high-risk type human papillomavirus (HR-HPV) in preneoplastic lesions and invasive squamous cell carcinoma (SCC) of the cervix uteri in southern Thai women. A total of 148 formalin-fixed, paraffin-embedded blocks of cervix tissue were retrieved from the files of the Department of Pathology, Prince of Songkla University Hospital. They were classified as negative for intraepithelial lesion (NIL) in 37 cases, low grade lesion (LGL) in 58 cases, high grade lesion (HGL) in 39 cases and SCC in 14 cases. HR-HPV DNA was tested with an Amplicor HPV (Roche Diagnostics) detection kit. Of the 111 cases, 42 of 58 LGLs (72.4%), 34 of 39 HGLs (87.2%) and 13 of 14 SCCs (92.9%) were positive for HR-HPV DNA. In 37 cases of histologically normal cervix, there were 15 cases that showed the presence of HR-HPV DNA. Applying the HR-HPV results for NILs to the general population, the age standardized incidence rate of HR-HPV infection in the normal Thai population was 12.8%. HR-HPV DNA can be found in all grades of intraepithelial lesions and carcinoma of the cervix uteri, even in the histologically "normal" looking cervix. These results provide strong evidence for a role in carcinogenesis of the cervix uteri and the existence of a non-productive or latent period of HPV infection.

  13. Automated Estimation Of Lesion Size

    NASA Astrophysics Data System (ADS)

    Ruttimann, Urs E.; Webber, Richard L.; Groenhuis, Roelf A. J.; Troullos, Emanuel; Rethman, Michael T.

    1985-06-01

    Two methods were studied of estimating automatically the relative volume of local lesions in digital subtractions radiographs. The first method approximates the projected, lesion area by an equivalent circular area, and the second by an equivalent polygonal area. Lesion volume is estimated in both methods as equivalent area times the average gray-level difference between the detected area and the surrounding background. Regression results of the estimated relative volume versus the calibrated size of lesions induced in dry human mandibles showed the polygonal approximation to be superior. This method also permitted successful monitoring of bone remodelling during the healing process of surgically induced lesions in dogs. The quantitative results, as well as the examples from in vivo lesions demonstrate feasibility and clinically relavance of the methodology.

  14. In vitro evaluation of the efficacy of laser fluorescence (DIAGNOdent) to detect demineralization and remineralization of smooth enamel lesions

    PubMed Central

    Bahrololoomi, Zahra; Musavi, Seyed Ahmad; Kabudan, Mona

    2013-01-01

    Objective: Early detection of smooth surface lesions is important for appropriate management and monitoring of dental caries. The purpose of this in vitro study was to evaluate the efficacy of laser fluorescence to detect demineralization and remineralization of smooth enamel surfaces. Materials and Methods: In this in vitro study, 132 enamel blocks of semi-impacted human third molars were obtained; artificial caries lesions were induced and they were submitted to the pH-cycling process to create remineralization. Superficial microhardness (SMH) and laser fluorescence (LF) analysis were performed at baseline, after demineralization, and remineralization processes. The data were analyzed by Statistical Package for Social Sciences (SPSS)-16 using analysis of variance (ANOVA), Paired samples t-test, and Pearson's correlation test. Results: There was a significant difference between SMH values at baseline, after demineralization and after remineralization. Also, a statistically significant difference was observed between LF values in these three stages. The LF values increased after demineralization and then decreased after remineralization, and the SMH values decreased after demineralization and increased after remineralization. There was an inverse relationship between SMH and LF only at baseline and after demineralization, but not after remineralization. Conclusion: The results showed that LF is an appropriate method for detection of demineralization in an in vitro condition in smooth enamel lesions, but it was not so efficient in the detection of remineralization. PMID:23956542

  15. 3-D Electrochemical Impedance Spectroscopy Mapping of Arteries to Detect Metabolically Active but Angiographically Invisible Atherosclerotic Lesions

    PubMed Central

    Packard, René R. Sevag; Luo, Yuan; Abiri, Parinaz; Jen, Nelson; Aksoy, Olcay; Suh, William M.; Tai, Yu-Chong; Hsiai, Tzung K.

    2017-01-01

    We designed a novel 6-point electrochemical impedance spectroscopy (EIS) sensor with 15 combinations of permutations for the 3-D mapping and detection of metabolically active atherosclerotic lesions. Two rows of 3 stretchable electrodes circumferentially separated by 120° were mounted on an inflatable balloon for intravascular deployment and endoluminal interrogation. The configuration and 15 permutations of 2-point EIS electrodes allowed for deep arterial penetration via alternating current (AC) to detect varying degrees of lipid burden with distinct impedance profiles (Ω). By virtue of the distinctive impedimetric signature of metabolically active atherosclerotic lesions, a detailed impedance map was acquired, with the 15 EIS permutations uncovering early stages of disease characterized by fatty streak lipid accumulation in the New Zealand White rabbit model of atherosclerosis. Both the equivalent circuit and statistical analyses corroborated the 3-D EIS permutations to detect small, angiographically invisible, lipid-rich lesions, with translational implications for early atherosclerotic disease detection and prevention of acute coronary syndromes or strokes. PMID:28744325

  16. Effect of slice thickness on detectability in breast CT using a prewhitened matched filter and simulated mass lesions

    PubMed Central

    Packard, Nathan J.; Abbey, Craig K.; Yang, Kai; Boone, John M.

    2012-01-01

    Purpose: Dedicated breast CT (bCT) is an emerging technology with the potential to improve the detection of breast cancer in screening and diagnostic capacities. Typically, the 3D volume reconstructed from the scanner is displayed as sectional images. The purpose of this study was to evaluate the effect of section thickness on the detectability of simulated masses using a prewhitened matched filter (PWMF) as a model observer. Methods: A breast CT scanner has been designed and fabricated in the authors’ laboratory with more than 200 women imaged in IRB-approved phase I and phase II trials to date. Of these, 151 bilateral data sets were selected on the basis of low artifact content, sufficient breast coverage, and excluding cases with breast implants. BIRADS breast density ratings were available for 144 of these patients. Spherical mass lesions of diameter 1, 2, 3, 5, 11, and 15 mm were mathematically generated and embedded at random locations within the parenchymal region of each bCT volume. Microcalcifications were not simulated in this study. For each viewing plane (sagittal, axial, and coronal) and section thickness (ranging from 0.3 to 44 mm), section images of the breast parenchyma containing the lesion were generated from the reconstructed bCT data sets by averaging voxels over the length of the section. Using signal known exactly (SKE) model observer methodology, receiver operating characteristic (ROC) curve analysis was performed on each generated projected image using a PWMF based model observer. ROC curves were generated for each breast data set, and the area under the ROC curve (AUC) was evaluated as well as the sensitivity at 95% specificity. Results: For all lesion sizes, performance rises modestly to a peak before falling off substantially as section thickness increases over the range of the study. We find that the optimal section thickness tracks the size of the lesion to be detected linearly with a small positive offset and slopes ranging from 0

  17. [Incidence of dependence-related lesions in a population of critical patients].

    PubMed

    Roca-Biosca, Alba; Rubio-Rico, Lourdes; de Molina-Fernández, María Inmaculada; Tuset-Garijo, Gemma; Colodrero-Díaz, Encarnación; García-Fernández, Francisco Pedro

    2016-01-01

    To determine the incidence of various types of dependence-related lesions (DRL) on a population of critically ill patients. Descriptive, longitudinal and prospective study in an Intensive Care Unit from January 2014 to January 2015. Adult patients who did not present DRL at the moment of admission were included. Those with brain death and/or stay at the unit for more than two days were excluded. Patients were studied till they developed DRL, were exitus, discharged or stayed for more than 14 days. Each patient was evaluated daily till DRL did develop or was excluded from the study. If DRL did develop it was photographed and related data were recorded. The comparison between quantitative variables of normal distribution was done with the t de Student. The Mann-Whitney U was used to compare the other variables. Qualitative variables were compared through Pearson's chi square. In both cases p≤.05 was considered significant. 295 patients were included, 27.45% of them developed DRL. The density of incidence was 41 DRL/1,000 days at risk. 50.62% of DRL were categorized as PU. 17.28% were moisture injuries, 13.58% were due to friction and the rest were combined injuries. The risk according to EMINA and Braden scale was significantly different in the group of patients with lesions compared to the group without them. Not all injuries were caused by pressure. Specific prevention strategies based on different causal mechanisms are required. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  18. Comparison of the accuracy of radiography and ultrasonography for detection of articular lesions in horses.

    PubMed

    Hinz, Antje; Fischer, Andrew T

    2011-10-01

    To compare the accuracy of ultrasonographic and radiographic examination for evaluation of articular lesions in horses. Cross-sectional study. Horses (n = 137) with articular lesions. Radiographic and ultrasonographic examinations of the affected joint(s) were performed before diagnostic or therapeutic arthroscopic surgery. Findings were recorded and compared to lesions identified during arthroscopy. In 254 joints, 432 lesions were identified by arthroscopy. The overall accuracy was 82.9% for ultrasonography and 62.2% for radiography (P < .0001) with a sensitivity of 91.4% for ultrasonography and 66.7% for radiography (P < .0001). The difference in specificity was not statistically significant (P = .2628). The negative predictive value for ultrasonography was 31.5% and 13.2% for radiography (P = .0022), the difference for the positive predictive value was not statistically significant (P = .3898). The accuracy for ultrasonography and radiography for left versus right joints was equal and corresponded with the overall results. Ultrasonographic evaluation of articular lesions was more accurate than radiographic evaluation. © Copyright 2011 by The American College of Veterinary Surgeons.

  19. Perirhinal cortex lesions impair tests of object recognition memory but spare novelty detection.

    PubMed

    Olarte-Sánchez, Cristian M; Amin, Eman; Warburton, E Clea; Aggleton, John P

    2015-12-01

    The present study examined why perirhinal cortex lesions in rats impair the spontaneous ability to select novel objects in preference to familiar objects, when both classes of object are presented simultaneously. The study began by repeating this standard finding, using a test of delayed object recognition memory. As expected, the perirhinal cortex lesions reduced the difference in exploration times for novel vs. familiar stimuli. In contrast, the same rats with perirhinal cortex lesions appeared to perform normally when the preferential exploration of novel vs. familiar objects was tested sequentially, i.e. when each trial consisted of only novel or only familiar objects. In addition, there was no indication that the perirhinal cortex lesions reduced total levels of object exploration for novel objects, as would be predicted if the lesions caused novel stimuli to appear familiar. Together, the results show that, in the absence of perirhinal cortex tissue, rats still receive signals of object novelty, although they may fail to link that information to the appropriate object. Consequently, these rats are impaired in discriminating the source of object novelty signals, leading to deficits on simultaneous choice tests of recognition.

  20. Photodynamic detection in visualisation of cutaneous and oral mucosa premalignant and malignant lesions: two clinical cases

    NASA Astrophysics Data System (ADS)

    Jurczyszyn, Kamil; Ziólkowski, Piotr; Osiecka, Beata; Gerber, Hanna; Dziedzic, Magdalena

    2008-11-01

    Photodynamic diagnosis (PDD) is promising method of visualisation of premalignant and malignant lesions. PDD is consisted of two main agents: special chemical compound which is called photosensitizer and light. Photosensitizer has affinity to fast proliferating cells such as pre- or malignant. During light irradiation (with proper wavelength - corresponding to absorption peak of photosensitizer) photosensitizer gains energy and passes into excited singlet state S1. Returning to basic singlet state Sn, leads to fluorescence. Due to difference between concentration of photosensitizer in lesion and normal tissue it is possible to obtain high contrast image of lesion. Case #1: 53 years old woman with basal cell carcinoma (BCC) in nasal region; 20% delta-aminolevulinic acid as a precursor of photosensitizer on eucerin base was used. Case #2: 57 years old woman with multifocal oral leukoplakia on cheek mucosa and tongue; 2% chlorophyll gel as photosesitizer was used. All photographs were taken in white light without any filter and in blue and UV light with orange filter: in both cases the total area of the lesions appeared to be larger than it has been clinically observed. Thus, the PDD might be helpful in evaluation of margins of surgical excision of such lesions.

  1. "Blind spots" in forensic autopsy: improved detection of retrobulbar hemorrhage and orbital lesions by postmortem computed tomography (PMCT).

    PubMed

    Flach, P M; Egli, T C; Bolliger, S A; Berger, N; Ampanozi, G; Thali, M J; Schweitzer, W

    2014-09-01

    The purpose of this study was to correlate the occurrence of retrobulbar hemorrhage (RBH) with mechanism of injury, external signs and autopsy findings to postmortem computed tomography (PMCT). Six-teen subjects presented with RBH and underwent PMCT, external inspection and conventional autopsy. External inspection was evaluated for findings of the bulbs, black eye, raccoon eyes and Battle's sign. Fractures of the viscerocranium, orbital lesions and RBH were evaluated by PMCT. Autopsy and PMCT was evaluated for orbital roof and basilar skull fracture. The leading manner of death was accident with central regulatory failure in cases of RBH (31.25%). Imaging showed a high sensitivity in detection of orbital roof and basilar skull fractures (100%), but was less specific compared to autopsy. Volume of RBH (0.1-2.4ml) correlated positively to the presence of Battle's sign (p<0.06) and the postmortem interval. Ecchymosis on external inspection correlated with RBH. There was a statistical significant correlation between bulbar lesion and RBH. Orbital roof fracture count weakly correlated with the total PMCT derived RBH volume. Maxillary hemosinus correlated to maxillary fractures, but not to RBH. RBH are a specific finding in forensically relevant head trauma. PMCT is an excellent tool in detecting and quantifying morphological trauma findings particularly in the viscerocranium, one of the most relevant "blind spots" of classic autopsy. PMCT was superior in detecting osseous lesions, scrutinizing autopsy as the gold standard. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. Stretchable electrochemical impedance sensors for intravascular detection of lipid-rich lesions in New Zealand White rabbits.

    PubMed

    Cao, Hung; Yu, Fei; Zhao, Yu; Scianmarello, Nick; Lee, Juhyun; Dai, Wangde; Jen, Nelson; Beebe, Tyler; Li, Rongsong; Ebrahimi, Ramin; Chang, Donald S; Mody, Freny V; Pacella, John; Tai, Yu-Chong; Hsiai, Tzung

    2014-04-15

    Flexible electronics have enabled catheter-based intravascular sensing. However, real-time interrogation of unstable plaque remains an unmet clinical challenge. Here, we demonstrate the feasibility of stretchable electrochemical impedance spectroscopy (EIS) sensors for endoluminal investigations in New Zealand White (NZW) rabbits on diet-induced hyperlipidemia. A parylene C (PAC)-based EIS sensor mounted on the surface of an inflatable silicone balloon affixed to the tip of an interrogating catheter was deployed (1) on the explants of NZW rabbit aorta for detection of lipid-rich atherosclerotic lesions, and (2) on live animals for demonstration of balloon inflation and EIS measurements. An input peak-to-peak AC voltage of 10 mV and sweeping-frequency from 300 kHz to 100 Hz were delivered to the endoluminal sites. Balloon inflation allowed EIS sensors to be in contact with endoluminal surface. In the oxidized low-density-lipoprotein (oxLDL)-rich lesions from explants of fat-fed rabbits, impedance magnitude increased significantly by 1.5-fold across the entire frequency band, and phase shifted ~5° at frequencies below 10 kHz. In the lesion-free sites of the normal diet-fed rabbits, impedance magnitude increased by 1.2-fold and phase shifted ~5° at frequencies above 30 kHz. Thus, we demonstrate the feasibility of stretchable intravascular EIS sensors for identification of lipid rich lesions, with a translational implication for detecting unstable lesions. © 2013 Published by Elsevier B.V.

  3. Correlation of radiographic measurements of structures of the equine foot with lesions detected on magnetic resonance imaging.

    PubMed

    de Zani, D; Polidori, C; di Giancamillo, M; Zani, D D

    2016-03-01

    There are few studies on the correlations between radiographic measurements of the foot and abnormalities of specific structures found with magnetic resonance imaging (MRI). To document the relationship between radiographic measurements of the equine foot and the presence of lesions in the foot on MRI. We hypothesised that different radiographic measurements would be associated with specific lesions detected by MRI. Retrospective analysis of radiographs and MRI studies. Seventy-four feet from 52 lame horses were included. Twenty parameters were measured on radiographs, whereas the signal intensity, homogeneity and size of each structure in the foot were evaluated on magnetic resonance images. The data were analysed using simple linear correlation analysis and classification and regression trees (CARTs). Linear correlations were found between the navicular bone compacta thickness and injuries of the deep digital flexor tendon, collateral sesamoidean ligament, navicular spongiosa and navicular bone proximal border. Long-toed horses had a high incidence of lesions involving the spongiosa and proximal border of the navicular bone. Elongation of the navicular bone was associated with proximal and distal border injuries. A reduced palmar angle and increased angle between the middle and distal phalanx were observed in horses with alterations of collateral ligaments of the distal interphalangeal joint and navicular bone spongiosa, respectively. For each structure under investigation, CARTs predicting the presence of MRI pathology based on radiographic measurements had excellent performance, with >80% correct classification of cases, when using one of 3 data sources. This study demonstrated a relationship between radiographic measurements of the foot and the presence of lesions detected on MRI, while CARTs illustrated that different radiographic measurements were associated with different MRI lesions. © 2015 EVJ Ltd.

  4. Lesser-known myelin-related disorders: focal tumour-like demyelinating lesions.

    PubMed

    Jiménez Arango, J A; Uribe Uribe, C S; Toro González, G

    2015-03-01

    Focal tumour-like demyelinating lesions are defined as solitary demyelinating lesions with a diameter greater than 2 cm. In imaging studies, these lesions may mimic a neoplasm or brain abscess; as a result, invasive diagnostic and therapeutic measures may be performed that will in some cases increase morbidity. Our aim was to analyse and characterise these lesions according to their clinical, radiological, and pathological characteristics, and this data in addition to our literature review will contribute to a better understanding of these lesions. This descriptive study includes 5 cases with pathological diagnoses. We provide subject characteristics gathered through reviewing their clinical, radiology, and pathology reports. Patients' ages ranged from 12 to 60 years; 3 patients were female. The time delay between symptom onset and hospital admission was 3 to 120 days. Clinical manifestations were diverse and dependent on the location of the lesion, pyramidal signs were found in 80% of patients, there were no clinical or radiological signs of spinal cord involvement, and follow-up times ranged from 1 to 15 years. Brain biopsy is the gold standard for the diagnosis of demyelinating tumour-like lesions; however, their clinical features, along with several magnetic resonance imaging features such as open ring enhancement, venular enhancement, the presence of glutamate in spectroscopy, and others, may be sufficient to differentiate neoplastic lesions from focal tumour-like demyelinating lesions. Copyright © 2012 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

  5. [P16(INK4alpha)/Ki-67 immunocytochemical dual staining for detection of cervical lesions associated to papillomavirus infection].

    PubMed

    Toro de Méndez, Morelva; Ferrández Izquierdo, Antonio; Llombart-Bosch, Antonio

    2014-09-01

    We aimed to explore the expression pattern of p16(INK4alpha)/Ki-67 immunocytochemical dual-staining and to establish the potential clinical utility for early detection of cervical lesions. Liquid-based cytologies of cervical specimens of cervical cancer screening were processed for p16(INK4alpha)/Ki-67 immunocytochemical dual-staining using the CINtec Plus Kit. HPV testing was performed with the INNO-LiPA HPV genotyping Extra Reverse Hybridization Line Probe Assay kit. One hundred and fifteen cervical cytologies were analyzed with the following results: 11(9.6%) were negative for intraepithelial lesions or malignancy (NILM); 32 (27.8%) presented atypical squamous cells of undetermined significance (ASC-US); 62 (53.9%) exhibited low grade squamous intraepithelial lesions (LSIL) and 10 (8.7%) showed high grade squamous intraepithelial lesions (HSIL). No cases of cervical cancer were detected. The overall prevalence of DNA HPV detection was 81.7% (94/115). The following specific HPV genotypes were identified in 42 (45.0%) cases: HPV16 (26.2%), HPV51 (21.4%), HPV52 (14.3%) and HPV66 (7.1%). Viral sequences of an unknown single HPV were detected in 23.8% of the cases. A total of 42/115 (36.5%) were p16(IVK4alpha)/Ki-67 dual-staining-positive, being more frequent in HSIL (70.0%), decreasing in LSIL (44.0%), detected in a minority of ASC-US (25.0%) and negative in NILM cases (p < 0.001). 40/115 cases (34.8%) were positive for both oncogenic HPV and p16(INK4alpha)/Ki-67 dual-staining, including 6/32 (18.8%) ASC-US, 26/62 (42.0%) LSIL and 8/10 (80.0%) HSIL, which represent a strong association between positivity for HPV, p16(INK4alpha)/Ki-67 staining and severe cytological abnormalities (p < 0.001). This methodology could be used to detect unnoticed cervical lesions.

  6. Relationships between hepatic neoplasms and related lesions and exposure to toxic chemicals in marine fish from the US West Coast

    SciTech Connect

    Myers, M.S.; Landahl, J.T.; Krahn, M.M.; McCain, B.B. )

    1991-01-01

    English sole (Parophrys vetulus) inhabiting polluted waterways and embayments of Puget Sound, Washington, are affected with a variety of multiple, co-occurring idiopathic hepatic lesions, including unique degenerative conditions, putatively preneoplastic foci of cellular alteration, and neoplasms. Results of a statistical analysis of the patterns of co-occurrence of these lesions in wild English sole are consistent with the concept that these lesions represent morphologically identifiable steps forming a sequence of progression ultimately leading to the development of hepatic neoplasms. The rationale for the hypothesis that these lesions in wild English sole can be caused by exposure to certain hepatoxic and hepatocarcinogenic xenobiotic compounds in the marine environment is based on the demonstration of significant and consistent statistical associations between levels of aromatic hydrocarbons (AHs) in sediment and prevalences of these idiopathic liver lesions; a significant contribution by sediment AHs to the variability in hepatic neoplasm prevalence in a logistic regression model; significantly increased probabilities for several idiopathic lesions in sole from chemically contaminated site in Puget Sound; significant correlations between uptake of polycyclic aromatic hydrocarbons and prevalences of several hepatic lesion types; and experimental induction of unique degenerative, proliferative, and putatively preneoplastic focal lesions in English sole injected with either benzo(a)pyrene or a polycyclic aromatic hydrocarbons (PAH) enriched fraction of an extract from a contaminated urban sediment from Puget Sound. Because PAHs are extensively metabolized in the liver of fish, sensitive and reliable methods for detection of PAH metabolites in fish tissues need to be developed before credible assessments of human health risk due to consumption of PAH-contaminated fish muscle can be conducted.

  7. HIV-related oral lesions, demographic factors, clinical staging and anti-retroviral use.

    PubMed

    Ramírez-Amador, Velia; Anaya-Saavedra, Gabriela; Calva, Juan J; Clemades-Pérez-de-Corcho, Tirso; López-Martínez, Carlos; González-Ramírez, Imelda; Sierra-Madero, Juan

    2006-07-01

    The aim of the present study was to compare the prevalence of HIV-related oral lesions (HIV-OL) between two health centers for HIV in Mexico City and to analyze the factors that, in addition to combined antiretroviral therapy (CART) and low CD4(+), may be associated with possible differences in prevalence. A cross-sectional observational study was performed between January 2000 and February 2003 at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INCMNSZ), a specialized referral center for HIV/AIDS patients and the Clínica Especializada Condesa (CEC), a primary care center for HIV-infected individuals without social security insurance. A consecutive sample of HIV-infected individuals had an oral examination based on established clinical criteria. Demographic, clinical and laboratory data were obtained. Independent association of each factor with specific HIV-OL was assessed by logistic regression modeling. Eight hundred fifty individuals were examined (INCMNSZ: 479; CEC: 371). Hairy leukoplakia (HL), periodontal disease (PD) and Kaposi's sarcoma (KS) were independently associated with the study site [odds ratio (OR) = 1.7 (95% confidence interval (CI): 1.1-2.4), OR = 4.2 (95% CI: 1.3-13), OR = 10.1 (95% CI: 2.7-38.2), respectively], being more frequent in CEC patients. HL was independently associated with men having sex with men OR = 1.7 (95% CI: 1.1-2.8). All HIV-OL were independently associated with CD4(+) counts and, with the exception of PD and KS, with time under CART. The present comparative study showed that several factors were associated with a difference in prevalence of oral lesions found in two AIDS clinics located in Mexico City. Severe immune suppression, CART duration and the study site were associated with HIV-OL. Further investigation into factors such as socioeconomic determinants associated with HIV-OL is warranted.

  8. Detection of prostate cancer index lesions with multiparametric magnetic resonance imaging (mp-MRI) using whole-mount histological sections as the reference standard.

    PubMed

    Russo, Filippo; Regge, Daniele; Armando, Enrico; Giannini, Valentina; Vignati, Anna; Mazzetti, Simone; Manfredi, Matteo; Bollito, Enrico; Correale, Loredana; Porpiglia, Francesco

    2016-07-01

    To evaluate the sensitivity of multiparametric magnetic resonance imaging (mp-MRI) for detecting prostate cancer foci, including the largest (index) lesions. In all, 115 patients with biopsy confirmed prostate cancer underwent mp-MRI before radical prostatectomy. A single expert radiologist recorded all prostate cancer foci including the index lesion 'blinded' to the pathologist's biopsy report. Stained whole-mount histological sections were used as the reference standard. All lesions were contoured by an experienced uropathologist who assessed their volume and pathological Gleason score. All lesions with a volume of >0.5 mL and/or pathological Gleason score of >6 were defined as clinically significant prostate cancer. Multivariate analysis was used to ascertain the characteristics of lesions identified by MRI. In all, 104 of 115 index lesions were correctly diagnosed by mp-MRI (sensitivity 90.4%; 95% confidence interval [CI] 83.5-95.1%), including 98/105 clinically significant index lesions (93.3%; 95% CI 86.8-97.3%), among which three of three lesions had a volume of <0.5 mL and Gleason score of >6. Overall, mp-MRI detected 131/206 lesions including 13 of 68 'insignificant' prostate cancers. The multivariate logistic regression modelling showed that pathological Gleason score (odds ratio [OR] 11.7, 95% CI 2.3-59.8; P = 0.003) and lesion volume (OR 4.24, 95% CI 1.3-14.7; P = 0.022) were independently associated with the detection of index lesions at MRI. This study shows that mp-MRI has a high sensitivity for detecting clinically significant prostate cancer index lesions, while having disappointing results for the detection of small-volume, low Gleason score prostate cancer foci. Thus, mp-MRI could be used to stratify patients according to risk, allowing better treatment selection. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.

  9. Multifocal hepatocellular carcinoma and precancerous lesions in a patient with autoimmune hepatitis-related cirrhosis.

    PubMed

    Ward, Stephen C; Deniz, Kemal; Roayaie, Sasan; Qin, Lihui

    2008-02-01

    A 44-year-old woman with a 29-year history of autoimmune hepatitis (AIH) received a living donor liver transplant for multifocal hepatocellular carcinoma (HCC) and cirrhosis in 2007. Her initial laboratory workup at our institution in 1996 revealed a positive antismooth muscle antibody with a titer of 1:640. Serum electrophoresis showed a monoclonal gamma globulin spike with elevated IgG, IgA, and IgM. The patient was negative for hepatitis B and hepatitis C (HCV) by serology and serum polymerase chain reaction. She was treated with corticosteroids and azathioprine, but her disease progressed. In 1997, a liver needle biopsy revealed cirrhosis and a focus of small cell change. In 2004, a 2-cm exophytic mass was detected on magnetic resonance imaging. Follow-up imaging in 2005 and 2006 showed growth of the exophytic mass and development of new tumors. The exophytic mass was treated with ethanol ablation and she received a transplant. Examination of the explant revealed multiple high-grade dysplastic nodules and four moderately differentiated HCCs, one of which is arising in a high-grade dysplastic nodule. We believe this to be the first case in the English literature documenting the presence of preneoplastic lesions in an HCV-negative patient with AIH who developed HCC.

  10. Incidence of lesions on Fungiidae corals in the eastern Red Sea is related to water temperature and coastal pollution.

    PubMed

    Furby, K A; Apprill, A; Cervino, J M; Ossolinski, J E; Hughen, K A

    2014-07-01

    As sea surface temperatures rise and the global human population increases, large-scale field observations of marine organism health and water quality are increasingly necessary. We investigated the health of corals from the family Fungiidae using visual observations in relation to water quality and microbial biogeochemistry parameters along 1300 km of the Red Sea coast of Saudi Arabia. At large scales, incidence of lesions caused by unidentified etiology showed consistent signs, increasing significantly from the northern to southern coast and positively correlated to annual mean seawater temperatures. Lesion abundance also increased to a maximum of 96% near the populous city of Jeddah. The presence of lesioned corals in the region surrounding Jeddah was strongly correlated with elevated concentrations of ammonium and changes in microbial communities that are linked to decreased water quality. This study suggests that both high seawater temperatures and nutrient pollution may play an indirect role in the formation of lesions on corals.

  11. [Diagnostic value of quantitative pharmacokinetic parameters and relative quantitative pharmacokinetic parameters in breast lesions with dynamic contrast-enhanced MRI].

    PubMed

    Sun, T T; Liu, W H; Zhang, Y Q; Li, L H; Wang, R; Ye, Y Y

    2017-08-01

    Objective: To explore the differential between the value of dynamic contrast-enhanced MRI quantitative pharmacokinetic parameters and relative pharmacokinetic quantitative parameters in breast lesions. Methods: Retrospective analysis of 255 patients(262 breast lesions) who was obtained by clinical palpation , ultrasound or full-field digital mammography , and then all lessions were pathologically confirmed in Zhongda Hospital, Southeast University from May 2012 to May 2016. A 3.0 T MRI scanner was used to obtain the quantitative MR pharmacokinetic parameters: volume transfer constant (K(trans)), exchange rate constant (k(ep))and extravascular extracellular volume fraction (V(e)). And measured the quantitative pharmacokinetic parameters of normal glands tissues which on the same side of the same level of the lesions; and then calculated the value of relative pharmacokinetic parameters: rK(rans)、rk(ep) and rV(e).To explore the diagnostic value of two pharmacokinetic parameters in differential diagnosis of benign and malignant breast lesions using receiver operating curves and model of logistic regression. Results: (1)There were significant differences between benign lesions and malignant lesions in K(trans) and k(ep) (t=15.489, 15.022, respectively, P<0.05), there were no significant differences between benign lesions and malignant lesions in V(e)(t=-2.346, P>0.05). The areas under the ROC curve(AUC)of K(trans), k(ep) and V(e) between malignant and benign lesions were 0.933, 0.948 and 0.387, the sensitivity of K(trans), k(ep) and V(e) were 77.1%, 85.0%, 51.0% , and the specificity of K(trans), k(ep) and V(e) were 96.3%, 93.6%, 60.8% for the differential diagnosis of breast lesions if taken the maximum Youden's index as cut-off. (2)There were significant differences between benign lesions and malignant lesions in rK(trans), rk(ep) and rV(e) (t=14.177, 11.726, 2.477, respectively, P<0.05). The AUC of rK(trans), rk(ep) and rV(e) between malignant and benign lesions

  12. Degree of Contracture Related to Residual Muscle Shoulder Strength in Children with Obstetric Brachial Plexus Lesions

    PubMed Central

    van Gelein Vitringa, Valerie M.; van Noort, Arthur; Ritt, Marco J. P. F.; van Royen, Barend J.; van der Sluijs, Johannes A.

    2015-01-01

    Background and Objectives  Little is known about the relation between residual muscle strength and joint contracture formation in neuromuscular disorders. This study aimed to investigate the relation between residual muscle strength and shoulder joint contractures in children with sequelae of obstetric brachial plexus lesion (OBPL). In OBPL a shoulder joint contracture is a frequent finding. We hypothesize that residual internal and external rotator strength and their balance are related to the extent of shoulder joint contracture. Methods  Clinical assessment was performed in 34 children (mean 10.0 years) with unilateral OBPL and Narakas classes I–III. External and internal rotation strengths were measured with the shoulder in neutral position using a handheld dynamometer. Strength on the affected side was given as percentage of the normal side. Contracture was assessed by passive internal and external rotations in degrees (in 0° abduction). Mallet classification was used for active shoulder function. Results  External and internal rotation strengths on the affected side were approximately 50% of the normal side and on average both equally affected: 56% (SD 18%) respectively 51% (SD 27%); r = 0.600, p = 0.000. Residual strengths were not related to passive internal or external rotation (p > 0.200). Internal rotation strength (r =  − 0.425, p <0.05) was related to Narakas class. Mallet score was related to external and internal rotation strengths (r = 0.451 and r = 0.515, respectively; p < 0.01). Conclusion  The intuitive notion that imbalances in residual muscle strength influence contracture formation cannot be confirmed in this study. Our results are of interest for the understanding of contracture formation in OBPL. PMID:27917235

  13. Degree of Contracture Related to Residual Muscle Shoulder Strength in Children with Obstetric Brachial Plexus Lesions.

    PubMed

    van Gelein Vitringa, Valerie M; van Noort, Arthur; Ritt, Marco J P F; van Royen, Barend J; van der Sluijs, Johannes A

    2015-12-01

     Little is known about the relation between residual muscle strength and joint contracture formation in neuromuscular disorders. This study aimed to investigate the relation between residual muscle strength and shoulder joint contractures in children with sequelae of obstetric brachial plexus lesion (OBPL). In OBPL a shoulder joint contracture is a frequent finding. We hypothesize that residual internal and external rotator strength and their balance are related to the extent of shoulder joint contracture.  Clinical assessment was performed in 34 children (mean 10.0 years) with unilateral OBPL and Narakas classes I-III. External and internal rotation strengths were measured with the shoulder in neutral position using a handheld dynamometer. Strength on the affected side was given as percentage of the normal side. Contracture was assessed by passive internal and external rotations in degrees (in 0° abduction). Mallet classification was used for active shoulder function.  External and internal rotation strengths on the affected side were approximately 50% of the normal side and on average both equally affected: 56% (SD 18%) respectively 51% (SD 27%); r = 0.600, p = 0.000. Residual strengths were not related to passive internal or external rotation (p > 0.200). Internal rotation strength (r =  - 0.425, p <0.05) was related to Narakas class. Mallet score was related to external and internal rotation strengths (r = 0.451 and r = 0.515, respectively; p < 0.01).  The intuitive notion that imbalances in residual muscle strength influence contracture formation cannot be confirmed in this study. Our results are of interest for the understanding of contracture formation in OBPL.

  14. Do mirror movements relate to hand function and timing of the brain lesion in children with unilateral cerebral palsy?

    PubMed

    Klingels, Katrijn; Jaspers, Ellen; Staudt, Martin; Guzzetta, Andrea; Mailleux, Lisa; Ortibus, Els; Feys, Hilde

    2016-07-01

    This study aimed to systematically map the severity of mirror movements in both hands in a prospective cohort of children with unilateral cerebral palsy, and to explore the relationship with hand function and brain lesion type. Seventy-eight children were included (41 males, 37 females; age 9y 4mo, SD 3y 1mo, range 5-15y). Mirror movements were scored during three repetitive tasks following Woods and Teuber criteria. Strength, tone, Melbourne Assessment, Jebsen-Taylor test, and Assisting Hand Assessment were evaluated. Lesions were classified into malformations (n=5), periventricular (n=43), cortico-subcortical (n=22), and postnatally acquired lesions (n=8). Significantly more mirror movements were observed in the non-paretic versus the paretic hand (p≤0.003). Higher mirror movement scores in the non-paretic hand significantly correlated with lower distal strength and lower scores on unimanual and bimanual assessments (r=0.29-0.41). In the paretic hand, significant differences were found between lesion types (p=0.03). The occurrence of mirror movements in the non-paretic hand seems related to hand function while mirror movements in the paretic hand seem more related to the lesion timing, whereby children with earlier lesions present with more mirror movements. © 2015 Mac Keith Press.

  15. Detection of retinal lesions in diabetic retinopathy: comparative evaluation of 7-field digital color photography versus red-free photography.

    PubMed

    Venkatesh, Pradeep; Sharma, Reetika; Vashist, Nagender; Vohra, Rajpal; Garg, Satpal

    2015-10-01

    Red-free light allows better detection of vascular lesions as this wavelength is absorbed by hemoglobin; however, the current gold standard for the detection and grading of diabetic retinopathy remains 7-field color fundus photography. The goal of this study was to compare the ability of 7-field fundus photography using red-free light to detect retinopathy lesions with corresponding images captured using standard 7-field color photography. Non-stereoscopic standard 7-field 30° digital color fundus photography and 7-field 30° digital red-free fundus photography were performed in 200 eyes of 103 patients with various grades of diabetic retinopathy ranging from mild to moderate non-proliferative diabetic retinopathy to proliferative diabetic retinopathy. The color images (n = 1,400) were studied with corresponding red-free images (n = 1,400) by one retina consultant (PV) and two senior residents training in retina. The various retinal lesions [microaneurysms, hemorrhages, hard exudates, soft exudates, intra-retinal microvascular anomalies (IRMA), neovascularization of the retina elsewhere (NVE), and neovascularization of the disc (NVD)] detected by all three observers in each of the photographs were noted followed by determination of agreement scores using κ values (range 0-1). Kappa coefficient was categorized as poor (≤0), slight (0.01-0.20), fair (0.2 -0.40), moderate (0.41-0.60), substantial (0.61-0.80), and almost perfect (0.81-1). The number of lesions detected by red-free images alone was higher for all observers and all abnormalities except hard exudates. Detection of IRMA was especially higher for all observers with red-free images. Between image pairs, there was substantial agreement for detection of hard exudates (average κ = 0.62, range 0.60-0.65) and moderate agreement for detection of hemorrhages (average κ = 0.52, range 0.45-0.58), soft exudates (average κ = 0.51, range 0.42-0.61), NVE (average κ = 0.47, range 0.39-0.53), and NVD

  16. Risk factors for saddle-related skin lesions on elephants used in the tourism industry in Thailand.

    PubMed

    Magda, Scarlett; Spohn, Olivia; Angkawanish, Taweepoke; Smith, Dale A; Pearl, David L

    2015-05-19

    Lesions related to working conditions and improper saddle design are a concern for a variety of working animals including elephants. The objectives of the present study were to determine the prevalence of cutaneous lesions in anatomic regions (i.e., neck, girth, back, tail) in contact with saddle-related equipment among elephants in Thailand working in the tourism industry, and to identify potential risk factors associated with these lesions. Data for this cross-sectional study were collected between May 2007 and July 2