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Sample records for relative lesion detection

  1. Novel lesion detection aids.

    PubMed

    Neuhaus, K W; Longbottom, C; Ellwood, R; Lussi, A

    2009-01-01

    Several non-invasive and novel aids for the detection of (and in some cases monitoring of) caries lesions have been introduced in the field of 'caries diagnostics' over the last 15 years. This chapter focusses on those available to dentists at the time of writing; continuing research is bound to lead to further developments in the coming years. Laser fluorescence is based on measurements of back-scattered fluorescence of a 655-nm light source. It enhances occlusal and (potentially) approximal lesion detection and enables semi-quantitative caries monitoring. Systematic reviews have identified false-positive results as a limitation. Quantitative light-induced fluorescence is another sensitive method to quantitatively detect and measure mineral loss both in enamel and some dentine lesions; again, the trade-offs with lower specificity when compared with clinical visual detection must be considered. Subtraction radiography is based on the principle of digitally superimposing two radiographs with exactly the same projection geometry. This method is applicable for approximal surfaces and occlusal caries involving dentine but is not yet widely available. Electrical caries measurements gather either site-specific or surface-specific information of teeth and tooth structure. Fixed-frequency devices perform best for occlusal dentine caries but the method has also shown promise for lesions in enamel and other tooth surfaces with multi-frequency approaches. All methods require further research and further validation in well-designed clinical trials. In the future, they could have useful applications in clinical practice as part of a personalized, comprehensive caries management system. PMID:19494675

  2. Relative efficacy of radiographic and radionuclide bone surveys in the detection of the skeletal lesions of histiocytosis X

    SciTech Connect

    Parker, B.R.; Pinckney, L.; Etcubanas, E.

    1980-02-01

    Radionuclide studies have been considered a more sensitive indicator of the presence of the bony lesions of histiocytosis X in children that have radiographic bone surveys. Our results suggest that the opposite is true. Although positive correlation between bone scans and radiographs was found in eight of nine patients, only 35% of the individual lesions visible on radiographs were seen on radionuclide studies. Results of radionuclide studies did not correlate with age or sex of the patient, presence or duration of symptoms, radiographic appearance, or anatomic location of lesions. Our results suggest that the radiographic skeletal survey is more sensitive than radionuclide studies in detecting the skeletal lesions of histiocytosis X.

  3. 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.

  4. Vaginal micropapillary lesions are not related to human papillomavirus infection: in situ hybridization and polymerase chain reaction detection techniques.

    PubMed

    Garzetti, G G; Ciavattini, A; Goteri, G; Menzo, S; De Nictolis, M; Clementi, M; Brugia, M; Romanini, C

    1994-01-01

    The objective of this study was to assess the human papillomavirus DNA presence in vaginal papillary lesions, with particular regard to micropapillomatosis to better define their clinical significance. Prospective study: the study population was composed of 62 women who were recruited consecutively from the Colposcopy Centre of the Ancona University, Department of Obstetrics and Gynecology, on the grounds of vaginal papillomatosis or/and typical acuminata warts. Biopsies for routine histology, and for human papillomavirus (HPV) DNA detection by means of in situ hybridization and polymerase chain reaction (PCR) were taken from the papillary lesions and from 24 healthy women, who were selected as controls. Macroscopically, vaginal micropapillomatosis was ascertained in 51 cases (82.3%), while in 11 cases (17.7%) the colposcopic diagnosis was condyloma acuminatum. During in situ hybridization, HPV DNA positivity was observed in 8 (9.4%) out of 85 samples of squamous papillae and in 11 (64.7%) out of 17 samples of condylomata; in control specimens, HPV DNA was detected in 2 (8.3%) out of 24 bioptic samples. The correspondence between in situ hybridization and PCR was 96.1%, with 17.4% more diagnosis obtained by PCR. Vaginal micropapillomatosis may be regarded as a variation in the normal anatomy of the lower genital tract without any significant relationship with HPV infection, and as a lesion easily distinguishable from condylomata acuminata by clinical examination alone. PMID:7959342

  5. 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.

  6. 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

  7. Computerized lesion detection on breast ultrasound.

    PubMed

    Drukker, Karen; Giger, Maryellen L; Horsch, Karla; Kupinski, Matthew A; Vyborny, Carl J; Mendelson, Ellen B

    2002-07-01

    We investigated the use of a radial gradient index (RGI) filtering technique to automatically detect lesions on breast ultrasound. After initial RGI filtering, a sensitivity of 87% at 0.76 false-positive detections per image was obtained on a database of 400 patients (757 images). Next, lesion candidates were segmented from the background by maximizing an average radial gradient (ARD) index for regions grown from the detected points. At an overlap of 0.4 with a radiologist lesion outline, 75% of the lesions were correctly detected. Subsequently, round robin analysis was used to assess the quality of the classification of lesion candidates into actual lesions and false-positives by a Bayesian neural network. The round robin analysis yielded an Az value of 0.84, and an overall performance by case of 94% sensitivity at 0.48 false-positives per image. Use of computerized analysis of breast sonograms may ultimately facilitate the use of sonography in breast cancer screening programs. PMID:12148724

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Dental students' ability to detect and diagnose oral mucosal lesions.

    PubMed

    Ali, Mohammad A; Joseph, Bobby K; Sundaram, Devipriya B

    2015-02-01

    The aim of this study was to assess the ability of dental students in the screening clinic of the Kuwait University Dental Center to detect and diagnose oral mucosal lesions. Clinical examinations performed by dental students between January 2009 and February 2011 were included. All their findings regarding the oral mucosal lesions and dental carious lesions detected were recorded, after which the patients were re-examined by faculty examiners. The students rated their own ability to detect mucosal and carious lesions before each examination. Among the 341 patients screened, 375 oral mucosal lesions were found by the faculty examiners. Of those, the students detected 178 (47.5%). Out of the 375 lesions, including the ones they failed to detect, the students diagnosed 272 (72.5%) correctly. The students were more likely (p≤0.01) to correctly diagnose a mucosal lesion when they themselves had detected it (n=169/178) than when they failed to detect it and had it subsequently pointed out by the faculty examiners (n=103/197). The students were more competent in detecting carious lesions (p≤0.001) than in detecting mucosal lesions. A significantly higher proportion of students who felt confident in detecting mucosal lesions were actually more competent in detecting the lesions than those who were not confident (p≤0.001). Further educational strategies are needed to motivate Kuwait University dental students to develop the knowledge, skills, and judgment necessary to integrate a complete intraoral examination into their routine practice. PMID:25640618

  13. Detection of breast lesions by holographic interferometry

    NASA Astrophysics Data System (ADS)

    Hong, HyunDae; Sheffer, Daniel B.; Loughry, C. William

    1999-07-01

    The holographic interferometry (HI) technique commonly used for nondestructive testing of laminate materials was applied to create fringe contour distortion near the site of indwelling breast lesions. For this medical imaging application, the HI technique was successful in demonstrating abnormal mechanical properties of living tissue. Adequate density and contrast of fringes, crucial factors necessary for analysis of surface deformation of an object, can be made only with an appropriate stressing method. We have applied vibration and mild pressure to the surface of female breasts for the purpose of detecting localized densities and mass alterations of the tissue, which may be indicative of an abnormality of that tissue. Even though each stressing method had both positive and negative aspects, pneumatic pressure was adopted for the present study because it was more suitable for a noninvasive and noncontact breast examination. We also developed a computer based holographic imaging system to precisely control the stressing phase for the pressure and laser triggering so the resultant holograms had manageable fringe density and repeatability.

  14. 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.

  15. 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.

  16. Phantom experiments to improve parathyroid lesion detection

    SciTech Connect

    Nichols, Kenneth J.; Tronco, Gene G.; Tomas, Maria B.; Kunjummen, Biju D.; Siripun, Lisa; Rini, Josephine N.; Palestro, Christopher J.

    2007-12-15

    This investigation tested the hypothesis that visual analysis of iteratively reconstructed tomograms by ordered subset expectation maximization (OSEM) provides the highest accuracy for localizing parathyroid lesions using {sup 99m}Tc-sestamibi SPECT data. From an Institutional Review Board approved retrospective review of 531 patients evaluated for parathyroid localization, image characteristics were determined for 85 {sup 99m}Tc-sestamibi SPECT studies originally read as equivocal (EQ). Seventy-two plexiglas phantoms using cylindrical simulated lesions were acquired for a clinically realistic range of counts (mean simulated lesion counts of 75{+-}50 counts/pixel) and target-to-background (T:B) ratios (range=2.0 to 8.0) to determine an optimal filter for OSEM. Two experienced nuclear physicians graded simulated lesions, blinded to whether chambers contained radioactivity or plain water, and two observers used the same scale to read all phantom and clinical SPECT studies, blinded to pathology findings and clinical information. For phantom data and all clinical data, T:B analyses were not statistically different for OSEM versus FB, but visual readings were significantly more accurate than T:B (88{+-}6% versus 68{+-}6%, p=0.001) for OSEM processing, and OSEM was significantly more accurate than FB for visual readings (88{+-}6% versus 58{+-}6%, p<0.0001). These data suggest that visual analysis of iteratively reconstructed MIBI tomograms should be incorporated into imaging protocols performed to localize parathyroid lesions.

  17. Computerized analysis of sonograms for the detection of breast lesions

    NASA Astrophysics Data System (ADS)

    Drukker, Karen; Giger, Maryellen L.; Horsch, Karla; Vyborny, Carl J.

    2002-05-01

    With a renewed interest in using non-ionizing radiation for the screening of high risk women, there is a clear role for a computerized detection aid in ultrasound. Thus, we are developing a computerized detection method for the localization of lesions on breast ultrasound images. The computerized detection scheme utilizes two methods. Firstly, a radial gradient index analysis is used to distinguish potential lesions from normal parenchyma. Secondly, an image skewness analysis is performed to identify posterior acoustic shadowing. We analyzed 400 cases (757 images) consisting of complex cysts, solid benign lesions, and malignant lesions. The detection method yielded an overall sensitivity of 95% by image, and 99% by case at a false-positive rate of 0.94 per image. In 51% of all images, only the lesion itself was detected, while in 5% of the images only the shadowing was identified. For malignant lesions these numbers were 37% and 9%, respectively. In summary, we have developed a computer detection method for lesions on ultrasound images of the breast, which may ultimately aid in breast cancer screening.

  18. 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. PMID:27215953

  19. 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. PMID:15889546

  20. What affects detectability of lesion-deficit relationships in lesion studies?

    PubMed

    Inoue, Kayo; Madhyastha, Tara; Rudrauf, David; Mehta, Sonya; Grabowski, Thomas

    2014-01-01

    Elucidating the brain basis for psychological processes and behavior is a fundamental aim of cognitive neuroscience. The lesion method, using voxel-based statistical analysis, is an important approach to this goal, identifying neural structures that are necessary for the support of specific mental operations, and complementing the strengths of functional imaging techniques. Lesion coverage in a population is by nature spatially heterogeneous and biased, systematically affecting the ability of lesion-deficit correlation methods to detect and localize functional associations. We have developed a simulator that allows investigators to model parameters in a lesion-deficit study and characterize the statistical bias in lesion deficit detection coverage that will result from specific assumptions. We used the simulator to assess the signal detection properties and localization accuracy of standard lesion-deficit correlation methods, under a simple truth model - that a critical region of interest (CR), when damaged, gives rise to a deficit. We considered voxel-based lesion-symptom mapping (VLSM) and proportional MAP-3 (PM3). Using regression analysis, we examined if the pattern of outcome statistics can be explained by simulation parameters, factors that are inherent to anatomic parcels, and lesion coverage of the population, which consisted of a representative sample of 351 subjects drawn from the Iowa Patient Registry. We examined the effect of using nonparametric versus parametric statistics to obtain thresholded maps and the effect of correcting for multiple comparisons using false discovery rate or cluster-based correction. Our results, which are derived from samples of realistic lesions, indicate that even a simple truth model yields localization errors that are systematic and pervasive, averaging 2 cm in the standard anatomic space, and tending to be directed towards areas of greater anatomic coverage. This displacement positions the center of mass of the detected

  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. PMID:27250113

  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

    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. 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

  5. Classification of dependence-related skin lesions: a new proposal.

    PubMed

    García-Fernández, F P; Soldevilla Agreda, J Javier; Pancorbo-Hidalgo, P L; Verdu-Soriano, J; López Casanova, P; Rodríguez-Palma, M

    2016-01-01

    A new theoretical framework on the development of pressure ulcers and other dependence-related lesions requires continued in-depth analysis of their conceptual bases. This study reports the historical background, definitions, and production mechanisms of these lesions, describing the differential pathognomonic features of pressure and/or shear ulcers, moisture-associated skin damage, and lesions from rubbing or friction. It also discusses the combined/multifactorial lesions that can be found in the clinical setting. Finally, it presents the new classification of these lesions proposed by the Spanish Pressure Ulcers and Chronic Wounds Advisory Panel. PMID:26762495

  6. 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.

  7. Isolated, relative aproverbia without focal lesion.

    PubMed

    Brown, Cora; Smith-Benjamin, Sarah; Patira, Riddhi; Altschuler, Eric L

    2016-06-01

    We have seen a patient with a profound, isolated, and quite selective deficit in proverb interpretation-aproverbia. The patient presented to us after an anoxic brain injury with aproverbia. Interestingly, the aproverbia appeared to be premorbid to the presenting event. Furthermore, the patient had no brain lesion that has been associated or even proposed as a cause of deficit in proverb or metaphor interpretation. The patient did have acute bilateral hippocampi lesions and associated severe anterograde amnesia, but he retained good retrograde memory with which he is able to give good, logical but concrete explanations for proverbs. This case highlights the need, importance, and interest in further neuropsychologic, imaging and functional studies of proverb and interpretation in patients and normal subjects populations. PMID:26836570

  8. Management of breast magnetic resonance imaging-detected lesions.

    PubMed

    Seely, Jean M

    2012-08-01

    Breast magnetic resonance imaging (MRI) has become an essential component of breast imaging. Whether it is used as a problem-solving tool or a screening test or for staging patients with breast cancer, it detects many lesions in the breast. The challenge for the radiologist is to distinguish significant from insignificant lesions and to direct their management. A brief summary of the terminology according to the American College of Radiologists lexicon will be provided. This review article will cover the differential diagnosis of enhancing lesions, including masses and nonmass enhancement, from benign and malignant causes. Some of the specific morphologic and kinetic features that help to differentiate benign from malignant lesions will be illustrated, and positive predictive values of these features will be reviewed. The various methods of investigating enhancing lesions of the breast will be discussed, including second-look ultrasound, ultrasound-guided biopsy, stereotactic biopsy, and MRI-guided biopsy. A practical approach to the management of MRI-detected lesions will include timing of follow-up, when to biopsy and when to ignore enhancing lesions in the breast. PMID:21798693

  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. Red lesion detection using background estimation and lesions characteristics in diabetic retinal image

    NASA Astrophysics Data System (ADS)

    Zhang, Dongbo; Peng, Yinghui; Yi, Yao; Shang, Xingyu

    2013-10-01

    Detection of red lesions [hemorrhages (HRs) and microaneurysms (MAs)] is crucial for the diagnosis of early diabetic retinopathy. A method based on background estimation and adapted to specific characteristics of HRs and MAs is proposed. Candidate red lesions are located by background estimation and Mahalanobis distance measure and then some adaptive postprocessing techniques, which include vessel detection, nonvessel exclusion based on shape analysis, and noise points exclusion by double-ring filter (only used for MAs detection), are conducted to remove nonlesion pixels. The method is evaluated on our collected image dataset, and experimental results show that it is better than or approximate to other previous approaches. It is effective to reduce the false-positive and false-negative results that arise from incomplete and inaccurate vessel structure.

  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. Detection and quantification of MS lesions using fuzzy topological principles

    NASA Astrophysics Data System (ADS)

    Udupa, Jayaram K.; Wei, Luogang; Samarasekera, Supun; Miki, Yukio; van Buchem, M. A.; Grossman, Robert I.

    1996-04-01

    Quantification of the severity of the multiple sclerosis (MS) disease through estimation of lesion volume via MR imaging is vital for understanding and monitoring the disease and its treatment. This paper presents a novel methodology and a system that can be routinely used for segmenting and estimating the volume of MS lesions via dual-echo spin-echo MR imagery. An operator indicates a few points in the images by pointing to the white matter, the gray matter, and the CSF. Each of these objects is then detected as a fuzzy connected set. The holes in the union of these objects correspond to potential lesion sites which are utilized to detect each potential lesion as a fuzzy connected object. These 3D objects are presented to the operator who indicates acceptance/rejection through the click of a mouse button. The volume of accepted lesions is then computed and output. Based on several evaluation studies and over 300 3D data sets that were processed, we conclude that the methodology is highly reliable and consistent, with a coefficient of variation (due to subjective operator actions) of less than 1.0% for volume.

  13. Depression in secondary epilepsy: relation to lesion laterality.

    PubMed Central

    Mendez, M F; Taylor, J L; Doss, R C; Salguero, P

    1994-01-01

    Patients with epilepsy often have depressive disorders. This association may be particularly prominent in secondary epilepsy from a left hemisphere lesion. Among 1611 outpatients with epilepsy 272 patients were identified whose seizures originated from a structural brain lesion other than mesial temporal sclerosis. Sustained depressive disorders had occurred in 25 (9%) of these patients with secondary epilepsy. The depressed patients were compared with the remaining patients without depression with regard to location of lesion laterality and seizure variables. The only group difference was unilateral left hemisphere lesions in 58% of the patients with depression compared with only 21% of the non-depressed patients (chi 2 = 10.4, p = 0.006). This finding supports the idea of a relation of depression with epileptogenic lesions in the left hemisphere. PMID:8126515

  14. Multiparametric MRI for Localized Prostate Cancer: Lesion Detection and Staging

    PubMed Central

    Margolis, Daniel J. A.

    2014-01-01

    Multiparametric MRI of the prostate combines high-resolution anatomic imaging with functional imaging of alterations in normal tissue caused by neoplastic transformation for the identification and characterization of in situ prostate cancer. Lesion detection relies on a systematic approach to the analysis of both anatomic and functional imaging using established criteria for the delineation of suspicious areas. Staging includes visual and functional analysis of the prostate “capsule” to determine if in situ disease is, in fact, organ-confined, as well as the evaluation of pelvic structures including lymph nodes and bones for the detection of metastasis. Although intertwined, the protocol can be optimized depending on whether lesion detection or staging is of the highest priority. PMID:25525600

  15. 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

  16. Bit-related lesions in Icelandic competition horses

    PubMed Central

    2014-01-01

    Background Oral lesions related to the use of the bit and bridle are reported to be common findings in horses worldwide and represent an important animal welfare issue. In order to provide an overview of bit-related lesions in Icelandic competition horses, a field examination of the rostral part of the oral cavity was performed in 424 competition horses coming to the two major national horse events in Iceland in 2012. Records from repeated examination of 77 horses prior to the finals were used to assess potential risk factors. Results Mild lesions were recorded in 152 horses (36%) prior to the preliminary rounds. They were most often located in the commissures of the lips and the adjacent buccal mucosa (n = 111). Severe lesions were found in 32 (8%) horses. For 77 horses examined prior to the finals, the frequency of findings in the area of the mandibular interdental space (bars of the mandible) had increased from 8% to 31% (P < 0.0001). These findings were most often (16/24) regarded as severe. The presence of lesions on the bars was strongly associated to the use of curb bits with a port (OR = 75, P = 0.009). Conclusions Bit-related lesions were found to be a general problem in Icelandic competition horses. The type of bits used influenced both the location and the severity of the lesions. The use of curb bits with a port was found to be a decisive risk factor for lesions on the bars of the mandible, most of which were regarded as severe. The results also raised questions about the head and neck carriage demanded for the competition horses. PMID:25116656

  17. Optical Detection of Preneoplastic Lesions of the Central Airways

    PubMed Central

    van der Leest, C.; Amelink, A.; van Klaveren, R. J.; Hoogsteden, H. C.; Sterenborg, H. J. C. M.; Aerts, J. G. J. V.

    2012-01-01

    Current routine diagnosis of premalignant lesions of the central airways is hampered due to a limited sensitivity (white light bronchoscopy) and resolution (computer tomography (CT), positron emission tomography (PET)) of currently used techniques. To improve the detection of these subtle mucosal abnormalities, novel optical imaging bronchoscopic techniques have been developed over the past decade. In this review we highlight the technological developments in the field of endoscopic imaging, and describe their advantages and disadvantages in clinical use. PMID:22550600

  18. 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.

  19. Detection of Intraplaque Hemorrhage in Mouse Atherosclerotic Lesions.

    PubMed

    Sluimer, Judith C; Gijbels, Marion J; Heeneman, Sylvia

    2015-01-01

    Intraplaque hemorrhage is defined as the presence of fresh or lysed erythrocytes, iron deposits in macrophages, and/or a fibrin clot in an atherosclerotic plaque. These features can be detected by hematoxylin and eosin, Martius scarlet Blue, and Perl's iron histological stainings. It is noteworthy that intraplaque hemorrhage is only present in murine atherosclerotic plaques after additional interventions or additional genetic traits affecting matrix degradation or thrombosis. In this chapter, we describe methods to detect intraplaque hemorrhage in mouse atherosclerotic lesions. PMID:26445801

  20. Detecting uterine glandular lesions: Role of cervical cytology

    PubMed Central

    Bansal, Baneet; Gupta, Parikshaa; Gupta, Nalini; Rajwanshi, Arvind; Suri, Vanita

    2016-01-01

    Background: The sensitivity of cervical cytology for detection of glandular lesions is reported to be low. We conducted this study to assess the diagnostic accuracy of cervical Papanicolaou (Pap) smears for uterine glandular lesions and to compare the diagnostic utility of conventional and liquid-based cytology (LBC) smears for glandular lesions. Materials and Methods: Archived histopathology records of all cases reported as endocervical and endometrial adenocarcinoma in the study period were identified and the available corresponding Pap smears (in preceding 1 year) were retrieved. In addition, the Pap smears reported as glandular cell abnormalities (GCA) during the same study period were retrieved. The overall prevalence of GCA, sensitivity, and specificity of Pap smears for the detection of GCA was calculated. The diagnostic accuracy of conventional and LBC smears for the diagnosis of GCA was also compared. Results: The prevalence of GCA in our study was 0.32%. The overall specificity of Pap smears for the diagnosis of GCA was 60.8%, this was not significantly different between conventional and LBC smears (P = 0.4). The overall sensitivity of Pap smears for the detection of GCA was 41.8%; LBC smears had significantly better sensitivity as compared to conventional smears for the detection of endometrial as compared to endocervical adenocarcinoma (P < 0.05). Conclusions: The prevalence of GCA in Pap smears is low. The specificity of Pap smears, for diagnosis of GCA, was found to be moderate. However, the overall sensitivity of Pap smears for the detection of GCA was low, though better for LBC as compared to conventional smears. PMID:27014363

  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. A soft kinetic data structure for lesion border detection

    PubMed Central

    Kockara, Sinan; Mete, Mutlu; Yip, Vincent; Lee, Brendan; Aydin, Kemal

    2010-01-01

    Motivation: The medical imaging and image processing techniques, ranging from microscopic to macroscopic, has become one of the main components of diagnostic procedures to assist dermatologists in their medical decision-making processes. Computer-aided segmentation and border detection on dermoscopic images is one of the core components of diagnostic procedures and therapeutic interventions for skin cancer. Automated assessment tools for dermoscopic images have become an important research field mainly because of inter- and intra-observer variations in human interpretations. In this study, a novel approach—graph spanner—for automatic border detection in dermoscopic images is proposed. In this approach, a proximity graph representation of dermoscopic images in order to detect regions and borders in skin lesion is presented. Results: Graph spanner approach is examined on a set of 100 dermoscopic images whose manually drawn borders by a dermatologist are used as the ground truth. Error rates, false positives and false negatives along with true positives and true negatives are quantified by digitally comparing results with manually determined borders from a dermatologist. The results show that the highest precision and recall rates obtained to determine lesion boundaries are 100%. However, accuracy of assessment averages out at 97.72% and borders errors' mean is 2.28% for whole dataset. Contact: skockara@uca.edu PMID:20529909

  3. 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. PMID:27603778

  4. 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

  5. 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.

  6. 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

  7. 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

  8. 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

  9. Diagnostic imaging strategy for MDCT- or MRI-detected breast lesions: use of targeted sonography

    PubMed Central

    2012-01-01

    Background Leading-edge technology such as magnetic resonance imaging (MRI) or computed tomography (CT) often reveals mammographically and ultrasonographically occult lesions. MRI is a well-documented, effective tool to evaluate these lesions; however, the detection rate of targeted sonography varies for MRI detected lesions, and its significance is not well established in diagnostic strategy of MRI detected lesions. We assessed the utility of targeted sonography for multidetector-row CT (MDCT)- or MRI-detected lesions in practice. Methods We retrospectively reviewed 695 patients with newly diagnosed breast cancer who were candidates for breast conserving surgery and underwent MDCT or MRI in our hospital between January 2004 and March 2011. Targeted sonography was performed in all MDCT- or MRI-detected lesions followed by imaging-guided biopsy. Patient background, histopathology features and the sizes of the lesions were compared among benign, malignant and follow-up groups. Results Of the 695 patients, 61 lesions in 56 patients were detected by MDCT or MRI. The MDCT- or MRI-detected lesions were identified by targeted sonography in 58 out of 61 lesions (95.1%). Patients with pathological diagnoses were significantly older and more likely to be postmenopausal than the follow-up patients. Pathological diagnosis proved to be benign in 20 cases and malignant in 25. The remaining 16 lesions have been followed up. Lesion size and shape were not significantly different among the benign, malignant and follow-up groups. Conclusions Approximately 95% of MDCT- or MRI-detected lesions were identified by targeted sonography, and nearly half of these lesions were pathologically proven malignancies in this study. Targeted sonography is a useful modality for MDCT- or MRI-detected breast lesions. PMID:22691539

  10. Multiscale AM-FM Methods for Diabetic Retinopathy Lesion Detection

    PubMed Central

    Murray, Victor; Barriga, Eduardo; Murillo, Sergio; Pattichis, Marios; Davis, Herbert; Russell, Stephen; Abràmoff, Michael; Soliz, Peter

    2010-01-01

    We propose the use of multiscale amplitude-modulation frequency-modulation (AM-FM) methods for discriminating between normal and pathological retinal images. The method presented in this paper is tested using standard images from the Early Treatment Diabetic Retinopathy Study (ETDRS). We use 120 regions of 40×40 pixels containing 4 types of lesions commonly associated with diabetic retinopathy (DR) and two types of normal retinal regions that were manually selected by a trained analyst. The region types included: microaneurysms, exudates, neovascularization on the retina, hemorrhages, normal retinal background, and normal vessels patterns. The cumulative distribution functions of the instantaneous amplitude, the instantaneous frequency magnitude, and the relative instantaneous frequency angle from multiple scales are used as texture features vectors. We use distance metrics between the extracted feature vectors to measure interstructure similarity. Our results demonstrate a statistical differentiation of normal retinal structures and pathological lesions based on AM-FM features. We further demonstrate our AM-FM methodology by applying it to classification of retinal images from the MESSIDOR database. Overall, the proposed methodology shows significant capability for use in automatic DR screening. PMID:20129850

  11. A new total body scanning system for automatic change detection in multiple pigmented skin lesions.

    PubMed

    Korotkov, Konstantin; Quintana, Josep; Puig, Susana; Malvehy, Josep; Garcia, Rafael

    2015-01-01

    The detection of newly appearing and changing pigmented skin lesions (PSLs) is essential for timely diagnosis of cutaneous melanoma. Total body skin examination (TBSE) procedures, currently practiced for this purpose, can be extremely time-consuming for patients with numerous lesions. In addition, these procedures are prone to subjectivity when selecting PSLs for baseline image comparison, increasing the risk of missing a developing cancer. To address this issue, we propose a new photogrammetry-based total body scanning system allowing for skin surface image acquisition using cross-polarized light. Equipped with 21 high-resolution cameras and a turntable, this scanner automatically acquires a set of overlapping images, covering 85%-90% of the patient's skin surface. These images are used for the automated mapping of PSLs and their change estimation between explorations. The maps produced relate images of individual lesions with their locations on the patient's body, solving the body-to-image and image-to-image correspondence problem in TBSEs. Currently, the scanner is limited to patients with sparse body hair and, for a complete skin examination, the scalp, palms, soles and inner arms should be photographed manually. The initial tests of the scanner showed that it can be successfully applied for automated mapping and temporal monitoring of multiple lesions: PSLs relevant for follow-up were repeatedly mapped in several explorations. Moreover, during the baseline image comparison, all lesions with artificially induced changes were correctly identified as "evolved." PMID:25222947

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

    PubMed

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

    2016-05-01

    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. PMID:27050294

  14. Detection and isolation of digital dermatitis treponemes from skin and tail lesions in pigs.

    PubMed

    Clegg, Simon R; Sullivan, Leigh E; Bell, Jennifer; Blowey, Roger W; Carter, Stuart D; Evans, Nicholas J

    2016-02-01

    Pig skin lesions are common significant welfare issues, and can cause large economic losses, due to culling of severely affected animals or carcass condemnation at slaughter. It was considered that the treponemal bacteria associated with digital dermatitis (DD) lesions in cattle, sheep and goats may have a role in these pig lesions. Specific diagnostic PCR assays for three cultivable DD Treponema phylogroups were used to survey relevant porcine lesion samples. Using these assays, DD treponemes were detected in 88% (22/25), 72% (8/11) and 82% (14/17) of tail, ear and flank lesions, respectively. Mouth swabs from animals kept in enclosures with high prevalence of skin lesions were positive for the DD treponemes, but not in enclosures with low lesion prevalence. Culture of treponemes from skin lesions resulted in pure isolates of all three DD-associated phylogroups. This study shows a strong association of DD treponemes with a range of pig skin lesions. PMID:26850539

  15. 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

  16. 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

  17. 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.

  18. 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

  19. Improved CSF classification and lesion detection in MR brain images with multiple sclerosis

    NASA Astrophysics Data System (ADS)

    Wolff, Yulian; Miron, Shmuel; Achiron, Anat; Greenspan, Hayit

    2007-03-01

    The study deals with the challenging task of automatic segmentation of MR brain images with multiple sclerosis lesions (MSL). Multi-Channel data is used, including "fast fluid attenuated inversion recovery" (fast FLAIR or FF), and statistical modeling tools are developed, in order to improve cerebrospinal fluid (CSF) classification and to detect MSL. Two new concepts are proposed for use within an EM framework. The first concept is the integration of prior knowledge as it relates to tissue behavior in different MRI modalities, with special attention given to the FF modality. The second concept deals with running the algorithm on a subset of the input that is most likely to be noise- and artifact-free data. This enables a more reliable learning of the Gaussian mixture model (GMM) parameters for brain tissue statistics. The proposed method focuses on the problematic CSF intensity distribution, which is a key to improved overall segmentation and lesion detection. A level-set based active contour stage is performed for lesion delineation, using gradient and shape properties combined with previously learned region intensity statistics. In the proposed scheme there is no need for preregistration of an atlas, a common characteristic in brain segmentation schemes. Experimental results on real data are presented.

  20. Targeted Ultrasound for MR-Detected Lesions in Breast Cancer Patients

    PubMed Central

    Shin, Jung Hee; Choe, Yeon Hyeon; Ko, Kyungran; Choi, Nami

    2007-01-01

    Objective To investigate the usefulness of targeted ultrasound (US) in the identification of additional suspicious lesions found by magnetic resonance (MR) imaging in breast cancer patients and the changes in treatment based on the identification of the lesions by the use of targeted US. Materials and Methods One-hundred forty nine patients who underwent breast MR imaging for a preoperative evaluation of breast cancer between January 2002 and July 2004 were included in the study. We searched all cases for any additional lesions that were found initially by MR imaging and investigated the performance of targeted US in identifying the lesions. We also investigated their pathological outcomes and changes in treatment as a result of lesion identification. Results Of the 149 patients with breast cancer, additional suspicious lesions were detected with MR imaging in 62 patients (42%). Of the 69 additional lesions found in those 62 patients, 26 (38%) were confirmed as cancers by histology. Thirty-eight lesions in 31 patients were examined with targeted US and were histologically revealed as cancers in 18 (47%), high risk lesions in two (5%), benign lesions in 15 (39%), and unidentified lesions in three (8%). The cancer rate was statistically higher in lesions with a US correlate than in lesions without a US correlate (p = 0.028). Of 31 patients, the surgical plan was altered in 27 (87%). The use of targeted US justified a change in treatment for 22 patients (81%) and misled five patients (19%) into having an unnecessary surgical excision. Conclusion Targeted US can play a useful role in the evaluation of additional suspicious lesions detected by MR imaging in breast cancer patients, but is limited in lesions without a US correlate. PMID:18071277

  1. Second-look ultrasonography for MRI-detected suspicious breast lesions in patients with breast cancer

    PubMed Central

    2015-01-01

    Purpose: The purpose of this study is to evaluate the use of second-look ultrasonography (US) for investigating additional suspicious lesions detected on preoperative staging magnetic resonance imaging (MRI) for breast cancer. Methods: Between September 2008 and August 2010, 1,970 breast MRIs were performed at our medical institution for the evaluation of breast cancer before surgery. Second-look US was recommended for 135 patients with 149 suspicious lesions, following the MRI interpretation, and 108 patients with 121 lesions were included in this study. The detection rate on second-look US, according to the lesion type, diameter, and histopathological outcome, was analyzed. Results: Of the 121 lesions considered in this study, 97 (80.2%) were diagnosed on MRI as masses and 24 (19.8%) as non-mass-like lesions; 105 lesions (86.8%) were correlated and 16 (13.2%) were not correlated with the findings of second-look US. Of the 105 correlated lesions, 29 (27.6%) were proven to be malignant and 76 (72.4%) were benign. Although a greater number of large malignant lesions were correlated on second-look US than small benign lesions, there was no statistically significant difference according to lesion diameter or type, as seen on MRI or pathology. Conclusion: We have concluded that second-look US is a useful diagnostic tool for lesions incidentally detected on breast MRI, as in this study, it could identify 86.8% of the MRI-detected breast lesions. PMID:25623054

  2. Computer aided root lesion detection using level set and complex wavelets

    NASA Astrophysics Data System (ADS)

    Li, Shuo; Fevens, Thomas; Krzyżak, Adam; Jin, Chao; Li, Song

    2007-03-01

    A computer aided root lesion detection method for digital dental X-rays is proposed using level set and complex wavelets. The detection method consists of two stages: preprocessing and root lesion detection. During preprocessing, a level set segmentation is applied to separate the teeth from the background. Tailored for the dental clinical environment, a segmentation clinical acceleration scheme is applied by using a support vector machine (SVM) classifier and individual principal component analysis (PCA) to provide an initial contour. Then, based on the segmentation result, root lesion detection is performed. Firstly, the teeth are isolated by the average intensity profile. Secondly, a center-line zero crossing based candidate generation is applied to generate the possible root lesion areas. Thirdly, the Dual-Tree Complex Wavelets Transform (DT-CWT) is used to further remove false positives. Lastly when the root lesion is detected, the area of root lesion is automatically marked with color indication representing different levels of seriousness. 150 real dental X-rays with various degrees of root lesions are used to test the proposed method. The results were validated by the dentist. Experimental results show that the proposed method is able to successfully detect the root lesion and provide visual assistance to the dentist.

  3. Capecitabine-related liver lesions: sinusoidal dilatation mimicking liver metastasis.

    PubMed

    Groom, Katherine; Penna, Marta; Arul, Dhili; Steward, Michael; Leonard, Pauline; Wilson, Jonathan

    2016-06-01

    A 30-year-old lady treated with capecitabine for primary colon adenocarcinoma developed liver lesions suspicious for metastasis. Liver biopsies showed sinusoidal dilatation thought to be secondary to capecitabine. This case highlights the importance of differentiating between benign and malignant liver lesions during cancer surveillance preventing unnecessary liver resections for benign disease. PMID:27398193

  4. Automatic Detection of Multiple Sclerosis Lesions in MR Brain Images

    PubMed Central

    Kapouleas, Ioannis

    1989-01-01

    This paper describes a system that locates lesions in Magnetic Resonance (MR) human brain images. The system uses new low level vision methods which successively identify the brain mass in the images, locate suspected lesions, sulci, and other normal structures. Other low level methods eliminate the majority of false positive lesions and locate certain landmarks such as the interhemispherical fissure. These methods take advantage of the special characteristics of MR images. A modeling method that employs b-spline surfaces has been developed to model the surfaces of the organs in a human brain in 3D. This method allows the model surfaces to be deformed in order to fit each individual patient's brain, and also allows the proportional deformation of the shapes of difficult-to-identify organs according to the deformation of easier-to-identify organs. The system calculates the appropriate position and orientation for the model by making use of landmarks within the patient's brain, and the moment of inertia method. The system uses both Proton Density and T2 sequences of images, in coronal and axial orientations. The various parts of the system have been tested extensively (on more than 1000 images from patients with Multiple Sclerosis lesions) with very good results. The methods developed here can also be used for other diagnostic tasks in radiology. ImagesFigures 1to7 10 11

  5. CANCER BIOMARKERS IN HUMAN ATHEROSCLEROTIC LESIONS: DETECTION OF DNA ADDUCTS

    EPA Science Inventory

    Since somatic mutations are suspected to contribute to the pathogenesis not only of cancer but also of atherosclerotic plaques, we measured DNA adducts in the smooth muscle layer of atherosclerotic lesions in abnormal aorta specimens taken at surgery from seven patients. NA adduc...

  6. The Diagnostic Value of Superb Microvascular Imaging (SMI) in Detecting Blood Flow Signals of Breast Lesions

    PubMed Central

    Ma, Yan; Li, Gang; Li, Jing; Ren, Wei-dong

    2015-01-01

    Abstract The correlation between color Doppler flow imaging (CDFI) and Superb Microvascular Imaging (SMI) for detecting blood flow in breast lesions was investigated, as was the diagnostic value of SMI in differentiating benign from malignant breast lesions. These lesions were evaluated using both CDFI and SMI according to Adler's method. Pathologic examination showed 57 malignant lesions and 66 benign lesions. The number of blood vessels in a single mass was detected by 2 techniques (SMI and CDFI), and the difference between the 2 values (SMI-CDFI) was calculated. The optimal threshold for the diagnosis of malignant neoplasms and the diagnostic performances of SMI, CDFI, and SMI-CDFI were calculated. For the total lesions and malignant lesions alone, the difference between SMI and CDFI for detecting blood flow was significant (P < 0.01), but the difference was not significant for benign lesions (P = 0.15). The area under the receiver operating characteristic curve was 0.73 (95% confidence interval [CI]: 0.64–0.82) for CDFI; 0.81 (95% CI: 0.74–0.89) for SMI; and 0.89 (95% CI: 0.82–0.95) for SMI-CDFI. Furthermore, the modality of “SMI-CDFI” showed the best diagnostic performance. SMI provides further microvessel information in breast lesions. The diagnostic modality of “SMI-CDFI” can improve the diagnostic performance of ultrasound in the differentiation between benign and malignant masses. PMID:26356718

  7. 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. PMID:27222730

  8. Clinical Impact of Ultrasound-Related Techniques on the Diagnosis of Focal Liver Lesions

    PubMed Central

    Salvatore, Veronica; Bolondi, Luigi

    2012-01-01

    Since its introduction in clinical practice, ultrasound technology has greatly impacted patient management, particularly in the case of liver diseases, where hepatologists usually perform ultrasound examinations. Clinicians are increasingly aware of the great potential of ultrasound waves and of the recent innovations that exploit the mechanical properties of ultrasound waves. Thus, at present, not only B-mode ultrasound but also contrast-enhanced ultrasound and, more recently, elastosonography are used worldwide in various settings. This review aims to describe why clinicians should be aware of ultrasound-based techniques, how they should use these techniques for assessing focal liver lesions, and how these techniques impact patient management. We will review the clinical potential of ultrasound-related techniques, starting from lesion detection, moving to characterization, and concluding with their utility in guiding treatments and analyzing their effects. PMID:24159588

  9. 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

  10. 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.

  11. 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

    2013-12-01

    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. PMID:24216694

  12. 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

  13. How do radiographic techniques affect mass lesion detection performance in digital mammography?

    NASA Astrophysics Data System (ADS)

    Huda, Walter; Ogden, Kent M.; Scalzetti, Ernest M.; Dudley, Eric F.; Dance, David R.

    2004-05-01

    We investigated how the x-ray tube kV and mAs affected the detection of simulated lesions with diameters between 0.24 and 12 mm. Digital mammograms were acquired with and without mass lesions, permitting a difference image to be generated corresponding to the lesion alone. Isolated digital lesions were added at a reduced intensity to non-lesion images, and used in Four-Alternate Forced Choice (4-AFC) experiments to determine the lesion intensity that corresponded to an accuracy of 92% (I92%). Values of I92% were determined at x-ray tube output values ranging from 40 to 120 mAs, and x-ray tube voltages ranging from 24 to 32 kV. For mass lesions larger than ~0.8 mm, there was no significant change in detection peformance with changing mAs. Doubling of the x-ray tube output from 60 to 120 mAs resulted in an average change in I92% of only +3.8%, whereas the Rose model of lesion detection predicts a reduction in the experimental value of I92% of -29%. For the 0.24 mm lesion, however, reducing the x-ray beam mAs from 100 to 40 mAs reduced the average detection performance by ~60%. Contrast-detail curves for lesions with diameter >= 0.8 mm had a slope of ~+0.23, whereas the Rose model predicts a slope of -0.5. For lesions smaller than ~0.8 mm, contrast-detail slopes were all negative with the average gradient increasing with decreasing mAs value. Increasing the x-ray tube voltage from 24 to 32 kV at a constant display contrast resulted in a modest improvement in low contrast lesion detection performance of ~10%. Increasing the display window width from 2000 to 2500 reduced the average observer performance by ~6%. Our principal finding is that radiographic technique factors have little effect on detection performance for lesions larger than ~0.8 mm, but that the visibility of smaller lesions is affected by quantum mottle in qualitative agreement with the predictions of the Rose model.

  14. Clinical Outcome of Magnetic Resonance Imaging-Detected Additional Lesions in Breast Cancer Patients

    PubMed Central

    Ha, Gi-Won; Yi, Mi Suk; Lee, Byoung Kil; Jung, Sung Hoo

    2011-01-01

    Purpose The aim of this study was to investigate the clinical outcome of additional breast lesions identified with breast magnetic resonance imaging (MRI) in breast cancer patients. Methods A total of 153 patients who underwent breast MRI between July 2006 and March 2008 were retrospectively reviewed. Thirty-three patients (21.6&) were recommended for second-look ultrasound (US) for further characterization of additional lesions detected on breast MRI and these patients constituted our study population. Results Assessment for lesions detected on breast MRI consisted of the following: 25 benign lesions (73.5&), two indeterminate (5.9%), and seven malignant (20.6%) in 33 patients. Second-look US identified 12 additional lesions in 34 lesions (35.3%) and these lesions were confirmed by histological examination. Of the 12 lesions found in the 11 patients, six (50.0%) including one contralateral breast cancer were malignant. The surgical plan was altered in 18.2% (six of 33) of the patients. The use of breast MRI justified a change in treatment for four patients (66.7%) and caused two patients (33.3&) to undergo unwarranted additional surgical procedures. Conclusion Breast MRI identified additional multifocal or contralateral cancer which was not detected initially on conventional imaging in breast cancer patients. Breast MRI has become an indispensable modality in conjunction with conventional modalities for preoperative evaluation of patients with operable breast cancer. PMID:22031803

  15. Automated lesion detection in dynamic contrast enhanced magnetic resonance imaging of breast

    NASA Astrophysics Data System (ADS)

    Liang, Xi; Kotagiri, Romamohanarao; Frazer, Helen; Yang, Qing

    2015-03-01

    We propose an automated method in detecting lesions to assist radiologists in interpreting dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) of breast. The aim is to highlight the suspicious regions of interest to reduce the searching time of the lesions and the possibility of radiologists overlooking small regions. In our method, we locate the suspicious regions by applying a threshold on essential features. The features are normalized to reduce the variation between patients. Support vector machine classifier is then applied to exclude normal tissues from these regions, using both kinetic and morphological features extracted in the lesions. In the evaluation of the system on 21 patients with 50 lesions, all lesions were successfully detected with 5.02 false positive regions per breast.

  16. Scintigraphic evaluation of hepatic mass lesions: emphasis on hemangioma detection.

    PubMed

    Middleton, M L

    1996-01-01

    Nuclear medicine imaging techniques continue to play a unique role in the evaluation of hepatic masses. Although many useful radiodiagnostic agents are available, the predominant nuclear medicine study used to evaluate hepatic masses in this decade is technetium-labeled red blood cell "blood-pool" scintigraphy. Hepatic blood-pool scintigraphy is extremely useful for the confirmation or exclusion of benign hepatic hemangiomas. This technique was first described in the 1970s and has vastly improved since that time. This improvement has been caused predominantly by advancements in instrumentation, especially the development of single photon emission computed tomography (SPECT) imaging. However, a perfusion/blood-pool mismatch remains unchanged as the hallmark finding for hepatic hemangiomas. The sensitivity and specificity of blood-pool scanning for the detection of hemangiomas has continued to increase over the years, and has not been equaled or surpassed by other radiographic modalities, with the possible exception of magnetic resonance imaging. Furthermore, blood-pool imaging is relatively inexpensive, simple to perform, and highly accurate. When a suspected hepatic hemangioma is confirmed by a positive radionuclide blood-pool study, the clinical evaluation of patients with hepatic masses can generally be terminated. PMID:8623050

  17. 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. PMID:25626557

  18. Ventromedial hypothalamic lesions change the expression of neuron-related genes and immune-related genes in rat liver.

    PubMed

    Kiba, Takayoshi; Kintaka, Yuri; Suzuki, Yoko; Nakata, Eiko; Ishigaki, Yasuhito; Inoue, Shuji

    2009-05-01

    There are no reports that hypothalamus can directly affect the expression of neuron-related genes and immune-related genes in liver. We identified genes of which expression profiles showed significant modulation in rat liver after ventromedial hypothalamic (VMH) lesions. Total RNA was extracted, and differences in the gene expression profiles between rats at day 3 after VMH lesioning and sham-VMH lesioned rats were investigated using DNA microarray analysis. The result revealed that VMH lesions regulated the genes that were involved in functions related to neuronal development and immunofunction in the liver. Real-time PCR also confirmed that gene expression of SULT4A1 was upregulated, but expression of ACSL1 and CISH were downregulated at day 3 after VMH lesions. VMH lesions may change the expression of neuron-related genes and immune-related genes in rat liver. PMID:19429097

  19. Carpet Lesions Detected at CT Colonography: Clinical, Imaging, and Pathologic Features

    PubMed Central

    Lam, Vu P.; Weiss, Jennifer M.; Kennedy, Gregory D.; Kim, David H.

    2014-01-01

    Purpose To describe carpet lesions (laterally spreading tumors ≥ 3 cm) detected at computed tomographic (CT) colonography, including their clinical, imaging, and pathologic features. Materials and Methods The imaging reports for 9152 consecutive adults undergoing initial CT colonography at a tertiary center were reviewed in this HIPAA-compliant, institutional review board–approved retrospective study to identify all potential carpet lesions detected at CT colonography. Carpet lesions were defined as morphologically flat, laterally spreading tumors 3 cm or larger. For those patients with neoplastic carpet lesions, CT colonography studies were analyzed to determine maximal lesion width and height, oral contrast material coating, segmental location, and computer-aided detection (CAD) findings. Demographic data and details of clinical treatment in these patients were reviewed. Results Eighteen carpet lesions in 18 patients (0.2%; mean age, 67.1 years; eight men, 10 women) were identified and were subsequently confirmed at colonoscopy and pathologic examination among 20 potential flat masses (≥3 cm) prospectively identified at CT colonography (there were two nonneoplastic rectal false-positive findings). No additional neoplastic carpet lesions were found in the cohort undergoing colonoscopy after CT colonography and/or surgery (there were no false-negatives). Mean lesion width was 46.5 mm (range, 30–80 mm); mean lesion height was 7.9 mm (range, 4–14 mm). Surface retention of oral contrast material was noted in all 18 cases. All but two lesions were located in the distal rectosigmoid or proximal right colon. At CAD, 17 (94.4%) lesions were detected (mean, 6.2 CAD marks per lesion). Sixteen lesions (88.9%) demonstrated advanced histologic features, including a villous component (n = 11), high-grade dysplasia (n = 4), and invasive cancer (n = 5). Sixteen patients (88.9%) required surgical treatment for complete excision. Conclusion CT colonography can effectively

  20. 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

  1. 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.

  2. Multi-stage osteolytic spinal bone lesion detection from CT data with internal sensitivity control

    NASA Astrophysics Data System (ADS)

    Wels, M.; Kelm, B. M.; Tsymbal, A.; Hammon, M.; Soza, G.; Sühling, M.; Cavallaro, A.; Comaniciu, D.

    2012-03-01

    Spinal bone lesion detection is a challenging and important task in cancer diagnosis and treatment monitoring. In this paper we present a method for fully-automatic osteolytic spinal bone lesion detection from 3D CT data. It is a multi-stage approach subsequently applying multiple discriminative models, i.e., multiple random forests, for lesion candidate detection and rejection to an input volume. For each detection stage an internal control mechanism ensures maintaining sensitivity on unseen true positive lesion candidates during training. This way a pre-defined target sensitivity score of the overall system can be taken into account at the time of model generation. For a lesion not only the center is detected but also, during post-processing, its spatial extension along the three spatial axes defined by the surrounding vertebral body's local coordinate system. Our method achieves a cross-validated sensitivity score of 75% and a mean false positive rate of 3.0 per volume on a data collection consisting of 34 patients with 105 osteolytic spinal bone lesions. The median sensitivity score is 86% at 2.0 false positives per volume.

  3. 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.

  4. Culprit versus non-culprit lesion related adverse cardiac events in patients with obstructive sleep apnoea

    PubMed Central

    Li, Ruogu; Loh, Kelvin; Loo, Germaine; Tai, Bee-Choo; Lee, Chi-Hang

    2013-01-01

    Background In patients with obstructive sleep apnoea (OSA), the relative contribution of culprit versus non-culprit lesions to subsequent major adverse cardiac events (MACE) after acute myocardial infarction (AMI) remains unknown. Elucidating this relationship will shed light on the contributions of OSA to the advancement of coronary artery disease. Methods In a cohort of 105 patients who underwent an overnight sleep study after AMI, 98 were diagnosed with OSA (Apnoea–Hypopnoea Index (AHI) ≥5). The clinical outcomes at 5-year follow-up were determined. MACE was defined as a composite of cardiac death, reinfarction and repeat revascularisation. A culprit lesion was defined as the lesion involved in the initial AMI, and a non-culprit lesion as any lesion in the entire coronary tree outside the culprit lesion. Results Eighteen patients (median AHI: 28.1) developed MACE, of whom 12 presented with reinfarction and 6 with repeat revascularisation for stable angina. There was no cardiac death. Based on repeated coronary angiography, the MACE was related to the culprit lesion in 4 patients and the non-culprit lesion in 12 patients. The lesion responsible for the MACE was indeterminate in 2 patients, as coronary angiography was declined. The median duration from index AMI to culprit lesion-related and non-culprit lesion-related MACE were 10.5 and 20 months, respectively. Conclusions The incidence of MACE among patients with OSA and AMI was 18.4%, and most of the events were related to non-culprit lesions rather than the culprit lesion during the initial AMI.

  5. The relative effects of cavitation and nonlinear ultrasound propagation on HIFU lesion dynamics in a tissue phantom

    NASA Astrophysics Data System (ADS)

    Khokhlova, Vera A.; Bailey, Michael R.; Reed, Justin; Kaczkowski, Peter J.

    2001-05-01

    The relative importance of the effects of acoustic nonlinearity and cavitation in HIFU lesion production is studied experimentally and theoretically in a polyacrylamide gel. A 2-MHz transducer of 40-mm diameter and 45-mm focal length was operated at different regimes of power, and in cw or duty-cycle regimes with equal mean intensity. Elevated static pressure was applied to suppress bubbles, increase boiling temperature, and thus to isolate the effect of acoustic nonlinearity in the enhancement of lesion production. Experimental data were compared with the results of simulations performed using a KZK acoustic model combined with the bioheat equation and thermal dose formulation. Boiling and the typical tadpole-shaped lesion shifting towards the transducer were observed under standard atmospheric pressure. No boiling was detected and a symmetric thermal lesion formed in the case of overpressure. A delay in lesion inception time was registered with overpressure, which was hypothesized to be due to suppressed microbubble dynamics. The effect of acoustic nonlinearity was revealed as a substantial decrease in the lesion inception time and an increase in the lesion size for high-amplitude waves under both standard and overpressure conditions. [Work supported by ONRIFO, NASA/NSBRI, NIH Fogarty, and CRDF grants.

  6. Diagnostic Accuracy of Mucosal Biopsy versus Endoscopic Mucosal Resection in Barrett's Esophagus and Related Superficial Lesions.

    PubMed

    Elsadek, Hany M; Radwan, Mamdouh M

    2015-01-01

    Background. Endoscopic surveillance for early detection of dysplastic or neoplastic changes in patients with Barrett's esophagus (BE) depends usually on biopsy. The diagnostic and therapeutic role of endoscopic mucosal resection (EMR) in BE is rapidly growing. Objective. The aim of this study was to check the accuracy of biopsy for precise histopathologic diagnosis of dysplasia and neoplasia, compared to EMR in patients having BE and related superficial esophageal lesions. Methods. A total of 48 patients with previously diagnosed BE (36 men, 12 women, mean age 49.75 ± 13.3 years) underwent routine surveillance endoscopic examination. Biopsies were taken from superficial lesions, if present, and otherwise from BE segments. Then, EMR was performed within three weeks. Results. Biopsy based histopathologic diagnoses were nondysplastic BE (NDBE), 22 cases; low-grade dysplasia (LGD), 14 cases; high-grade dysplasia (HGD), 8 cases; intramucosal carcinoma (IMC), two cases; and invasive adenocarcinoma (IAC), two cases. EMR based diagnosis differed from biopsy based diagnosis (either upgrading or downgrading) in 20 cases (41.67%), (Kappa = 0.43, 95% CI: 0.170-0.69). Conclusions. Biopsy is not a satisfactory method for accurate diagnosis of dysplastic or neoplastic changes in BE patients with or without suspicious superficial lesions. EMR should therefore be the preferred diagnostic method in such patients. PMID:27347544

  7. Silent cerebral events/lesions related to atrial fibrillation ablation: a clinical review.

    PubMed

    Deneke, Thomas; Jais, Pierre; Scaglione, Marco; Schmitt, Rainer; DI Biase, Luigi; Christopoulos, Georgios; Schade, Anja; Mügge, Andreas; Bansmann, Martin; Nentwich, Karin; Müller, Patrick; Krug, Joachim; Roos, Markus; Halbfass, Phillip; Natale, Andrea; Gaita, Fiorenzo; Haines, David

    2015-04-01

    Brain magnetic resonance imaging (MRI) has identified a high incidence of cerebral ischemia in asymptomatic patients after atrial fibrillation (AF) ablation (silent). Detection of cerebral ischemic events on MRI is based on acute hyperintense lesions on diffusion-weighted imaging. In the literature, the incidence is related to specifications of MRI and depends on the definition applied. In comparative studies, silent cerebral events (SCE, diffusion-weighted MRI [DWI] positive only) appear to be approximately 3 times more common compared to using a definition of silent cerebral lesions (SCL; without fluid attenuated inverse recovery sequence [FLAIR] positivity). Whereas the FLAIR sequence may turn positive within days after the ischemic event, SCE definition is highly sensitive for early phases of ischemic brain damage. SCE/SCL appear to represent cerebral ischemic infarcts and determine the "embolic fingerprint" of a specific ablation technology and strategy used. The optimum time point for detecting SCE is early after AF ablation (24-72 hours), whereas detection of SCL can only be performed within the first 2-7 days (due to delay of FLAIR positivity). Different technology-, procedure-, and patient-related parameters have been identified to play a role in the multifactorial genesis of SCE/SCL. In recent years, evidence has been gathered that there may be differences of SCE/SCL rates depending upon the ablation technology used, but small patient numbers and a large number of potential confounders hamper all studies. As major findings of recent studies, mode of periprocedural and intraprocedural anticoagulation has been identified as a major predictor for incidences of SCE/SCL. Whereas procedural characteristics related to higher SCE/SCL-rates may be modified, unchangeable patient-related factors should be taken into account for future individualized risk assessment. Novel ablation devices introduced into the market should be tested for their potential embolic

  8. 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. PMID:21799393

  9. 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.

  10. 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. PMID

  11. 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

  12. 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.

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

    PubMed

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

    2015-07-21

    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. PMID:26134119

  14. 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.

  15. 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.

  16. 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

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

    PubMed

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

    2016-03-01

    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

  18. Combining CRF and multi-hypothesis detection for accurate lesion segmentation in breast sonograms.

    PubMed

    Hao, Zhihui; Wang, Qiang; Seong, Yeong Kyeong; Lee, Jong-Ha; Ren, Haibing; Kim, Ji-yeun

    2012-01-01

    The implementation of lesion segmentation for breast ultrasound image relies on several diagnostic rules on intensity, texture, etc. In this paper, we propose a novel algorithm to achieve a comprehensive decision upon these rules by incorporating image over-segmentation and lesion detection in a pairwise CRF model, rather than a term-by-term translation. Multiple detection hypotheses are used to propagate object-level cues to segments and a unified classifier is trained based on the concatenated features. The experimental results show that our algorithm can avoid the drawbacks of separate detection or bottom-up segmentation, and can deal with very complicated cases. PMID:23285589

  19. 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.

  20. Superficial esophageal lesions detected by endoscopic ultrasound enhanced with submucosal edema

    PubMed Central

    Li, Jian-Jun; He, Long-Jun; Shan, Hong-Bo; Wang, Thomas D; Xiong, Huan; Chen, Li-Ming; Xu, Guo-Liang; Li, Xiao-Hai; Huang, Xin-Xin; Luo, Guang-Yu; Li, Yin; Zhang, Rong

    2013-01-01

    AIM: To determine if there is consistency between endoscopic ultrasound (EUS) findings and pathological results for detecting lesions of different depth in the esophageal mucosa. METHODS: A canine (Beagle) model was established in which lesions of different depths were created in the esophageal mucosa by thermal burning. Seventy-two hours later, these lesions and adjacent tissue in the esophagus were examined by EUS. EUS findings including infiltrating depth, strength of echogenicity and homogeneity were recorded. Dogs were sacrificed and tissue specimens were obtained. We then compared the EUS findings with the pathology reports. RESULTS: Thermal burns created at different power settings caused lesions of different depth in the esophageal mucosa. When the echo strength was shifted from high, medium, to low echogenicity, an increase in the infiltrating depth of the lesion was noted, which coincided with results of the pathology examination. Obvious submucosal edema visualized by EUS was also detected by pathology. Furthermore, because of the enhancement caused by the submucosal edema, the lesions invading into the submucosa were easily visualized by EUS. CONCLUSION: There is consistency between EUS findings and pathological results of esophageal lesions with different depths. Submucosal edema can serve as an ultrasonic contrast agent. PMID:24379628

  1. 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

  2. Display conditions and lesion detectability: effect of background light

    NASA Astrophysics Data System (ADS)

    Razavi, Mahmood; Hall, Theodore R.; Aberle, Denise R.; Hayrapetian, Alek S.; Loloyan, Mansur; Eldredge, Sandra L.

    1990-08-01

    We assessed the effect of high background light on observer performance for the detection of a variety of chest radiographic abnormalities. Five observers reviewed 66 digital hard copy chest images formatted to 1 1 x 14 inch size under two display conditions: 1) on a specially prepared 1 1 x 14 inch illuminated panel with no peripheral light and 2) on a standard viewing panel designed for 14 x 17 inch radiographs. The images contained one - or more of the following conditions: pneumothorax, interstitial disease, nodules, alveolar process, or no abnormality. The results of receiver operator characteristic analysis show that extraneous light does reduce observer performance and the detectability of nodules, interstitial disease.

  3. Detection of Focal Cortical Dysplasia Lesions in MRI Using Textural Features

    NASA Astrophysics Data System (ADS)

    Loyek, Christian; Woermann, Friedrich G.; Nattkemper, Tim W.

    Focal cortical dysplasia (FCD) is a frequent cause of medically refractory partial epilepsy. The visual identification of FCD lesions on magnetic resonance images (MRI) is a challenging task in standard radiological analysis. Quantitative image analysis which tries to assist in the diagnosis of FCD lesions is an active field of research. In this work we investigate the potential of different texture features, in order to explore to what extent they are suitable for detecting lesional tissue. As a result we can show first promising results based on segmentation and texture classification.

  4. 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

  5. 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

  6. Impact of TOF PET on whole-body oncologic studies: a human observer lesion detection and localization study

    PubMed Central

    Surti, Suleman; Scheuermann, Joshua; Fakhri, Georges El; Daube-Witherspoon, Margaret E.; Lim, Ruth; Abi-Hatem, Nathalie; Moussallem, Elie; Benard, Francois; Mankoff, David; Karp, Joel S.

    2011-01-01

    lesion in small or large patients. This imaging protocol also provides similar performance over all patient sizes for lesions in the same organ type with similar relative uptake, indicating an ability to provide a uniform clinical diagnostic capability in most oncologic lesion detection tasks. PMID:21498523

  7. 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

  8. Improvement in Lesion Detection with Whole – Body Oncologic TOF - PET

    PubMed Central

    El Fakhri, Georges; Surti, Suleman; Trott, Cathryn M.; Scheuermann, Joshua; Karp, Joel S.

    2011-01-01

    Time of Flight (TOF) PET has great potential in whole-body oncological applications and recent work has demonstrated qualitatively in patient studies the improvement that can be achieved in lesion visibility. The aim of this work was to objectively quantify the improvement in lesion detectability that can be achieved in pulmonary and hepatic lesions with whole body FDG TOF-PET in a cohort of 100 patients as a function of patient body mass index (BMI), lesion location and contrast, and scanning time. Methods 100 patients with BMIs ranging from 16 to 45 were included in this study. Artificial 1-cm spherical lesions were imaged separately in air at variable locations of each patient’s lung and liver, appropriately attenuated and incorporated in the patient listmode data with four different lesion-to-background contrast ranges. The fused studies with artificial lesion present or absent were reconstructed using a listmode, un-relaxed OSEM with chronologically ordered subsets and a Gaussian TOF kernel for TOF reconstruction. Conditions were compared on the basis of performance of a 3-channel Hotelling observer (CHO-SNR) in detecting the presence of a sphere of unknown size on an anatomic background while modeling observer noise. Results TOF-PET yielded an improvement in lesion detection performance (ratio of CHO-SNR) over non-TOF PET of 8.3% in the liver and 15.1% in the lungs. The improvement in all lesions was 20.3, 12.0, 9.2 and 7.5% for mean contrast values of 2.0:1, 3.2:1, 4.4:1, and 5.7:1, respectively. Furthermore, this improvement was 9.8% in patients with BMI<30 and 11.1% in patients with BMI>30. Performance plateaued faster as a function of number of iterations with TOF than non-TOF. Conclusion TOF-PET yielded a significant improvement in lesion detection in oncologic studies over all contrasts and BMIs that was greater for lower lesion contrast. This improvement was achieved without compromising other aspects of PET imaging. PMID:21321265

  9. 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.

  10. 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.

  11. 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.

  12. 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…

  13. Prevalence of gastric precancerous lesions among chronic dyspeptic patients and related common risk factors.

    PubMed

    Ajdarkosh, Hossein; Sohrabi, Masoudreza; Moradniani, Mosayeb; Rakhshani, Naser; Sotodeh, Masoud; Hemmasi, Gholamreza; Khoonsari, Mahmood; Ameli, Mitra; Malekzadeh, Reza; Zamani, Farhad

    2015-09-01

    Gastric cancer is one of the leading causes of cancer-related deaths worldwide. Progression of gastric cancer follows several steps from gastritis to atrophy, intestinal metaplasia, dysplasia, and finally cancer. The aim of this study was to determine the prevalence of gastric precancerous lesions and related common risk factors in a group of chronic dyspeptic patients. A total of 688 chronic dyspeptic patients older than 40 years of age were consecutively enrolled. The exclusion criteria were pregnancy, and a history of gastric cancer and gastric surgery. A questionnaire including demographic and clinical data, smoking habits, alcohol use, NSAIDs, and regular aspirin use was completed for all patients. Upper endoscopy and gastric biopsy were performed for all of the participants according to the standard protocols. Upper endoscopy was performed for all of the participants and biopsies were taken according to the biopsy protocol. The specimens were examined in a blinded manner by two expert gastrointestinal pathologists. The mean age of the participants was 57.87±9.10 years; there were 361 (52.5%) women. The prevalence of intestinal metaplasia, gastric atrophy, dysplasia, and positive Helicobacter pylori infection was 19.8, 12.8, 3.2%, and 64.5%, respectively. Age and H. pylori infection showed a significant association with pathological findings (odds ratio=3.10, 95% confidence interval: 1.91-4.72 and odds ratio=3.56, 95% confidence interval: 2.30-5.53, respectively). According to the high prevalence of precancerous lesions in patients with chronic dyspepsia who were older than 40 years of age, upper endoscopy and gastric mapping sampling for the detection of these lesions is recommended in intermediate-risk to high-risk areas. PMID:25793916

  14. 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.

  15. 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.

  16. MR imaging section profile optimization: improved contrast and detection of lesions.

    PubMed

    Runge, V M; Wood, M L; Kaufman, D M; Silver, M S

    1988-06-01

    A computer-optimized radio-frequency (RF) pulse for sharper section definition was implemented for T2-weighted magnetic resonance (MR) imaging of the head. Twenty-four patients underwent MR imaging with this technique and also with a conventional spin-echo technique with a sinc pulse filtered with a Hamming window. The contrast between gray and white matter improved 20%-40%, depending on the echo time. In ten patients with multiple sclerosis, use of the computer-optimized RF pulse resulted in detection of 37% more lesions, and power deposition was reduced by 36%. The computer-optimized RF pulse improved image contrast and lesion detection. PMID:3363149

  17. The Relation between canine cognitive dysfunction and age-related brain lesions

    PubMed Central

    OZAWA, Makiko; CHAMBERS, James K.; UCHIDA, Kazuyuki; NAKAYAMA, Hiroyuki

    2016-01-01

    Canine cognitive dysfunction (CCD) is a syndrome that manifests itself in abnormal behaviors, such as disorientation and wandering. β-amyloid deposition in the brain, including the senile plaque (SP) and cerebral amyloid angiopathy (CAA), has been suggested as a major cause of the syndrome. However, the pathological significance of β-amyloid deposition in CCD dogs remains unclear. The present study was conducted using 16 dogs aged 10 years or older to clarify the relationship between the age-related histopathological lesions, such as β-amyloid deposition, in the brain and the clinical symptoms of CCD as evaluated in a questionnaire previously established in a large survey. In addition, age-related brain lesions were assessed in 37 dogs. The pathological lesions were evaluated by the severity of β-amyloid deposition (SP and CAA), the amount of ubiquitin-positive granules (UBQ), GFAP-positive astrocytes, Iba-1-positive microglia and Nissle stain-positive nerve cells. The results revealed that there was no significant correlation between the severities of canine SP and CCD. The SP increased until 14 years old, but decreased thereafter, although the incidence of CCD is high at these ages. The CAA consistently increased with age, but did not correlate greatly with the CCD score. In contrast, the increases of UBQ, astrocytes and microglia were significantly correlated with CCD. Thus, the impairment in the synapse and/or myelin suggested by increased UBQ and glial activation might be involved in CCD pathogenesis, but β-amyloid deposition, especially SP, is not a direct pathogenic factor of CCD. PMID:26922972

  18. Radiologists' Performance for Detecting Lesions and the Interobserver Variability of Automated Whole Breast Ultrasound

    PubMed Central

    Kim, Sung Hun; Choi, Byung Gil; Choi, Jae Jung; Lee, Ji Hye; Song, Byung Joo; Choe, Byung Joo; Park, Sarah; Kim, Hyunbin

    2013-01-01

    Objective To compare the detection performance of the automated whole breast ultrasound (AWUS) with that of the hand-held breast ultrasound (HHUS) and to evaluate the interobserver variability in the interpretation of the AWUS. Materials and Methods AWUS was performed in 38 breast cancer patients. A total of 66 lesions were included: 38 breast cancers, 12 additional malignancies and 16 benign lesions. Three breast radiologists independently reviewed the AWUS data and analyzed the breast lesions according to the BI-RADS classification. Results The detection rate of malignancies was 98.0% for HHUS and 90.0%, 88.0% and 96.0% for the three readers of the AWUS. The sensitivity and the specificity were 98.0% and 62.5% in HHUS, 90.0% and 87.5% for reader 1, 88.0% and 81.3% for reader 2, and 96.0% and 93.8% for reader 3, in AWUS. There was no significant difference in the radiologists' detection performance, sensitivity and specificity (p > 0.05) between the two modalities. The interobserver agreement was fair to good for the ultrasonographic features, categorization, size, and the location of breast masses. Conclusion AWUS is thought to be useful for detecting breast lesions. In comparison with HHUS, AWUS shows no significant difference in the detection rate, sensitivity and the specificity, with high degrees of interobserver agreement. PMID:23482698

  19. 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.

  20. Usefulness of a fluorescence visualization system for the detection of oral precancerous and early cancerous lesions.

    PubMed

    Ohnishi, Yuichi; Fujii, Tomoko; Ugaki, Yoshihide; Yasui, Hiroki; Watanabe, Masahiro; Dateoka, Suguru; Kakudo, Kenji

    2016-07-01

    Early detection of precancerous and early cancerous lesions could greatly reduce both the mortality and morbidity of oral cancer. The objective of this study was to analyze a fluorescence visualization (FV) system for the detection of precancerous and early cancerous lesions in rat tongue carcinogenesis and human oral cancerous lesions using for the first time a 4NQO rat model and human tissue. Based on the results from the rat tongue carcinogenesis model, under direct FV, the normal oral mucosa emitted various shades of pale green autofluorescence. In the precancerous and early cancerous cases, the lesion appeared as an irregular dark area. Histological examination of the lesions showed that the VELscope system had a sensitivity of 95% and specificity of 100% in discriminating normal mucosa from dysplasia/carcinoma in situ (CIS) or invasive carcinoma. The proliferating cell nuclear antigen (PCNA) protein level was gradually increased with progression of carcinogenic transformation. Furthermore, the results of PCNA and FV loss (FVL) were correlated. Next, results from 17 patients were also presented. Histological examination of the lesions showed that the VELscope system had a sensitivity of 95% and specificity of 100% in discriminating normal mucosa from severe dysplasia/CIS or invasive carcinoma. There were no normal epithelium cells in any of the FVL regions. Furthermore, to clarify the usefulness of FV compared to vital staining with iodine, we investigated the surgical margins of early oral squamous cell carcinoma (OSCC) tissues and compared the FVL and iodine unstained area (IU). The percentage of various types of dysplasia were almost equal when comparing the FVL and IU. These results suggest that this direct FV device has the potential for simple, cost-effective screening, detection and margin determination of oral precancerous and early cancerous lesions. PMID:27121913

  1. 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.

  2. Detection and activity assessment of primary coronal caries lesions: a methodologic study.

    PubMed

    Ekstrand, Kim Rud; Martignon, Stefania; Ricketts, David James Nigel; Qvist, Vibeke

    2007-01-01

    This study has three main objectives: Study (1) test the reproducibility and accuracy of the ICDAS I and ICDAS II caries detection systems; Study (2) validate a new impression material (Clinpro, 3M ESPE), which is said to detect lactic acid in plaque fermenting sucrose; Study (3) devise and test a scoring system for the assessment of caries activity of coronal lesions. Study (1): 141 extracted teeth were examined by two examiners using the ICDAS I and ICDAS II caries detection systems and validated against a histological classification system. Study (2): The accuracy of the impression material in predicting plaque with pH lower/higher than 5.5 was determined in an in situ study of 45 root dentin specimens by comparing the color change in the impression with the actual pH of the plaque, determined with a pH meter. Study (3): A scoring system to assess lesion activity was devised based on the predictive power of the visual appearance of the lesion (ICDAS II system), location of the lesion in a plaque stagnation area and, finally, the tactile feeling, rough/soft or smooth/hard, when running a perio-probe over the lesion. The accuracy was tested in a clinical study of 35 children with 225 lesions/sound surfaces and was validated using the Clinpro impression material for construct validity. Study (1): Intra- and inter-examiner reproducibility was found to be excellent (Kappa-values > 0.82) and the associations strong (Spearmans correlation coefficients > 0.90). Study (2): The Clinpro impression material was found to be acceptable as compared to the results of a pH meter, the combined sensitivity and specificity was 1.63. Study (3): ROC analysis showed that the devised classification system for determining lesion activity had acceptable accuracy (area under curve = 0.84 and the highest combined sum of specificity and sensitivity was 1.67). Thus, it is possible to predict lesion depth and assess the activity of primary coronal caries lesions accurately by using the

  3. Importance of Defect Detectability in Positron Emission Tomography Imaging of Abdominal Lesions

    PubMed Central

    Yamashita, Shozo; Yokoyama, Kunihiko; Onoguchi, Masahisa; Yamamoto, Haruki; Nakaichi, Tetsu; Tsuji, Shiro; Nakajima, Kenichi

    2015-01-01

    Objective(s): This study was designed to assess defect detectability in positron emission tomography (PET) imaging of abdominal lesions. Methods: A National Electrical Manufactures Association International Electrotechnical Commission phantom was used. The simulated abdominal lesion was scanned for 10 min using dynamic list-mode acquisition method. Images, acquired with scan duration of 1-10 min, were reconstructed using VUE point HD and a 4.7 mm full-width at half-maximum (FWHM) Gaussian filter. Iteration-subset combinations of 2-16 and 2-32 were used. Visual and physical analyses were performed using the acquired images. To sequentially evaluate defect detectability in clinical settings, we examined two middle-aged male subjects. One had a liver cyst (approximately 10 mm in diameter) and the other suffered from pancreatic cancer with an inner defect region (approximately 9 mm in diameter). Results: In the phantom study, at least 6 and 3 min acquisition durations were required to visualize 10 and 13 mm defect spheres, respectively. On the other hand, spheres with diameters ≥17 mm could be detected even if the acquisition duration was only 1 min. The visual scores were significantly correlated with background (BG) variability. In clinical settings, the liver cyst could be slightly visualized with an acquisition duration of 6 min, although image quality was suboptimal. For pancreatic cancer, the acquisition duration of 3 min was insufficient to clearly describe the defect region. Conclusion: The improvement of BG variability is the most important factor for enhancing lesion detection. Our clinical scan duration (3 min/bed) may not be suitable for the detection of small lesions or accurate tumor delineation since an acquisition duration of at least 6 min is required to visualize 10 mm lesions, regardless of reconstruction parameters. Improvements in defect detectability are important for radiation treatment planning and accurate PET-based diagnosis. PMID:27408887

  4. [Outcome of "well-differentiated jargon" and related lesions].

    PubMed

    Nagai, Chiyoko; Takeda, Takahiro; Yoshizawa, Hiroshi; Iwata, Makoto

    2005-06-01

    We introduce "well-differentiated jargon" as a new type of jargon with two relevant cases. To give a simple and clear framework to a classification of jargon, we define three types of jargon as follows: Under the condition that utterance does not decrease remarkably, (1) If approximately 90% of whole utterance consists of real words and clear syntactic structure though incomprehensible, it is "well-differentiated jargon". (2) If approximately 90% of whole utterance consists of unclear phonemes or phonemes that are not able to divide into words, it is "undifferentiated jargon". (3) If in-comprehensible utterance does not belong to any type of jargon above, it is "moderately-differentiated jargon". In this line of definition, "well-differentiated jargon" is the most highly differentiated jargon. The following cases are the examples of "well-differentiated jargon": Case 1 was a 67-year-old woman with head injury of the left orbital cortex, prefrontal cortex, and temporal pole; Case 2 was a 64-year-old man with brain atrophy in bilateral frontal cortex and bilateral (right dominant) anteroinferior temporal cortex after meningoencephalitis. Within six months after onset, they showed characteristic verbal aspects as follows; transcortical sensory aphasia; utterance with a lot of perseverative error, irrelevant words, unnecessary qualifiers during the naming task; well-preserved syntactic structure in a sentence with a few neologism. One year after the first verbal assessment, the performance of Case 1 improved almost entirely, whereas characteristic utterance was still observed in Case 2. These results suggest that "well-differentiated jargon" can be caused by lesions in anteroinferior temporal cortex and prefrontal cortex with preserved language area, where involve more anterior region than that of classical jargon. These two cases cannot belong to any classical jargon, and then we insist the adoption of new type of jargon, "well-differentiated jargon". PMID:16026046

  5. 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.

  6. 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

  7. Rectovesical Fistula Related to Transurethral Resection of a Bladder Lesion

    PubMed Central

    Topaktaş, Ramazan; Tepeler, Abdulkadir; Kurt, Omer; Erdem, Mehmet Remzi; Armağan, Abdullah; Önol, Şinasi Yavuz

    2011-01-01

    A rectovesical fistula (RVF) is an uncommon complication of urooncologic surgery. Although several RVFs have been reported, our case is the first reported RVF in the literature that iatrogenically occurred after transurethral resection of the bladder. A single-stage primary repair with omental flap interposition without a colostomy was successfully performed because of the persistence of the fistula during followup. After 6 months of followup, no fistula or bladder mass was detected. PMID:21969833

  8. Detection and classification of retinal lesions for grading of diabetic retinopathy.

    PubMed

    Usman Akram, M; Khalid, Shehzad; Tariq, Anam; Khan, Shoab A; Azam, Farooque

    2014-02-01

    Diabetic Retinopathy (DR) is an eye abnormality in which the human retina is affected due to an increasing amount of insulin in blood. The early detection and diagnosis of DR is vital to save the vision of diabetes patients. The early signs of DR which appear on the surface of the retina are microaneurysms, haemorrhages, and exudates. In this paper, we propose a system consisting of a novel hybrid classifier for the detection of retinal lesions. The proposed system consists of preprocessing, extraction of candidate lesions, feature set formulation, and classification. In preprocessing, the system eliminates background pixels and extracts the blood vessels and optic disc from the digital retinal image. The candidate lesion detection phase extracts, using filter banks, all regions which may possibly have any type of lesion. A feature set based on different descriptors, such as shape, intensity, and statistics, is formulated for each possible candidate region: this further helps in classifying that region. This paper presents an extension of the m-Mediods based modeling approach, and combines it with a Gaussian Mixture Model in an ensemble to form a hybrid classifier to improve the accuracy of the classification. The proposed system is assessed using standard fundus image databases with the help of performance parameters, such as, sensitivity, specificity, accuracy, and the Receiver Operating Characteristics curves for statistical analysis. PMID:24480176

  9. Oral lesions, HIV phenotypes, and management of HIV-related disease: Workshop 4A.

    PubMed

    Patton, L L; Ranganathan, K; Naidoo, S; Bhayat, A; Balasundaram, S; Adeyemi, O; Taiwo, O; Speicher, D J; Chandra, L

    2011-04-01

    The workshop considered 5 questions related to oral lesions, HIV phenotypes, and the management of HIV-related disease, with a focus on evidence and challenges in resource-poor settings. First, are oral lesions unique with respect to geographic location or phenotype? Second, how useful would an oral lesion index be to predict HIV in resource-poor countries with no access to CD4 counts or viral load? Third, what are the latest methods and delivery modes for drugs used to treat oral lesions associated with HIV? Fourth, what is the role of the oral health care worker in rapid diagnostic testing for HIV? Fifth, what ethical and legal issues are to be considered when managing the HIV patient? The consensus of the workshop was the need for additional research in 4 key areas in developing countries: (1) additional investigation of comorbidities associated with HIV infection that may affect oral lesion presentation and distribution, especially in pediatric populations; (2) the development of region-specific algorithms involving HIV oral lesions, indicating cumulative risk of immune suppression and the presence of HIV disease; (3) well-designed clinical trials to test new therapies for oral lesions, new treatments for resistant oral fungal and viral diseases, effectiveness of therapies in children, and new drug delivery systems; and (4) the role of the oral health care worker in rapid diagnostic testing for HIV in various regions of the world. PMID:21441491

  10. 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

  11. [Detection of human papillomavirus (H.P.V.) DNA in genital lesions using molecular hybridization].

    PubMed

    Meguenni, S; el-Mehdaoui, S; Bandoui, D; Bouguermouh, A; Allouache, A; Bendib, A; Chouiter, A; Djenaoui, T; Lalliam, N; Bouhadef, A

    1992-01-01

    Detection of human papilloma virus in genitals lesions by molecular hybridization. Some H.P.V. types are sexually transmitted and infect genital organs. We have used molecular hybridization to examine the distribution of H.P.V. 6 or II and H.P.V. 16 in benign, premalignant and malignant genital lesions from 344 patients. The frequency of H.P.V. 16 positive cases increases as the cervical lesions progress to malignancy: 57/78 are positive (73%) in the carcinomas, 29/83 are positive (35%) in mild or moderate dysplasia. The majority of benign condylomata acuminata harbors DNA of other types, namely H.P.V. 6 and II. PMID:1339249

  12. Sun exposure related methylation in malignant and non-malignant skin lesions.

    PubMed

    Sathyanarayana, Ubaradka G; Moore, Angela Yen; Li, Lin; Padar, Asha; Majmudar, Kuntal; Stastny, Victor; Makarla, Prakash; Suzuki, Makoto; Minna, John D; Feng, Ziding; Gazdar, Adi F

    2007-01-01

    We investigated the aberrant promoter methylation status of 12 genes in skin lesions, both malignant (basal cell carcinomas (BCCs), n=68 and squamous cell carcinomas (SCCs), n=35) and non-malignant (tags, n=58) skin lesions and compared the results of lesions from sun exposed (SE) and sun protected (SP) regions. Methylation was studied using a methylation specific PCR (MSP) and methylation of CDH1 was also measured using a semi-quantitative fluorescence based real-time MSP method. The methylation index (MI) was calculated as the methylated fraction of the genes examined. In this report, we found high frequencies of methylation of several known or suspected tumor suppressor genes in tags and skin cancers. Among the 12 genes, for the cadherin genes CDH1 and CDH3 and for two of the laminin 5 encoding genes LAMA3 and LAMC2 methylation frequencies greater than 30% were noted in one or more specimen types. We investigated whether methylation was tumor related. Surprisingly, the differences in the methylation profile of genes among the three specimen types were modest, and the MI, indicators of overall methylation frequencies, was nearly identical. However, significant differences were noted in the frequencies of methylation among the three specimen types for the genes RASSF1A (P=0.002), CDH1 (P=0.007) and one or more of three CAD genes (P=0.02). Methylation was highly significantly related to sun exposure, and sun protected specimens had little or no methylation. As methylation of CDH1 was completely SE specific we analyzed all the skin samples using a semi-quantitative real-time PCR assay for the CDH1 gene. The concordance between standard MSP and real-time MSP for all the samples (n=161) was 75% (P<0.0001). While weak signals were detected in the SP samples by real time PCR, the differences between SE and SP specimens were 148 fold for tags and 390 fold for BCCs. These differences were highly significant (P<0.0001). These findings suggest that methylation commences in

  13. Image processing of head CT images using neuro best contrast (NBC) and lesion detection performance

    NASA Astrophysics Data System (ADS)

    Tipnis, Sameer; Vincent, Diana; Rumboldt, Zoran; Huda, Walter

    2011-03-01

    Purpose: The purpose of this study was to objectively compare lesion detection performance of head CT images reconstructed using filtered back projection (FBP) algorithms with those reconstructed using NBC. Method: The observer study was conducted using the 2-AFC methodology. An AFC experiment consists of 128 observer choices and permits the computation of the intensity needed to achieve 92% correct (I92%). High values of I92% corresponds to a poor level of detection performance, and vice versa. Head CT images were acquired at an x-ray tube voltage of 120 kVp with a CTDIvol value of 75 mGy in a helical scan. Nine randomly selected normal images from three patients and at three anatomical head locations were reconstructed using filtered back projection (FBP) and neuro-best-contrast (NBC) processing. Circular lesions were generated by projecting spheres onto the image plane, followed by blurring function, with lesion sizes of 2.8 mm, 6.5 mm and 9.8 mm used in these experiments. Four readers were used, with 18 experiments performed by each observer (2 processing techniques × 3 lesion sizes × 3 repeats). The experimental order of the 18 experiments was randomized to eliminate learning curve and/or observer fatigue. The ratio R of the I92% value for NBC to the corresponding I92% value for FBP was calculated for each observer and each lesion size. Values of R greater than unity indicate that NBC is inferior to FBP, and vice versa. Results: Analysis of data from each observer showed that a total of four data points had R less than unity, and eight data points were greater than unity. Eleven of the twelve individual observer R values with one standard deviation of unity. When data for the four observers were pooled, the resultant average R values were 0.98 +/- 0.38, 0.96 +/- 0.33 and 1.15 +/- 0.45, for the 2.8 mm, 6.5 mm and 9.8 mm lesions respectively. The overall average R for all three lesions sizes was 1.03 +/- 0.67. Conclusion: Our AFC investigation has shown no

  14. 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.

  15. 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.

  16. 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. PMID:24264647

  17. Fluorescence detection of tumors: studies on the early diagnosis of microscopic lesions in preclinical and clinical studies

    NASA Astrophysics Data System (ADS)

    Mang, Thomas S.; McGinnis, Carolyn; Crean, David H.; Khan, S.; Liebow, Charles

    1991-06-01

    The growth of microscopic tumor lesions at or beyond treatment field lesions poses major problems in the diagnosis and curative treatment of numerous cancers. Early detection techniques which clearly define the extent of condemned or field spread of disease may improve the primary treatment of the disease. In vivo fluorescence photometry is a non-imaging technique which digitally displays relative fluorescence values in volts. The sensitivity of the instrument has allowed the detection of micrometastases in both pre-clinical and clinical studies using drug doses that are 80-90 lower than those used therapeutically. This technique is now being applied in preliminary experiments to the hamster cheek pouch models to (1) discern varying grades of dysplasia; (2) levels of uptake of the drug in normal growing and quiescent tumors. Results will be shown in two models in which this technique has shown to be efficacious preclinically in the Pollard rat adenocarcinoma model in which micrometastases in the lymph node have been detected, and preliminary studies involving the hamster cheek pouch model in which the pouch is painted with 9, 10 dimethyl-1, 2-benzanthracene (DMBA) for initiation and promotion of tumors. Clinically results will be shown in which fluorescence detection, confirmed by biopsy and histopathological examination, was capable of detecting the existence of micrometastatic involvement of less than 100 cells.

  18. Three-dimensional tracking of lesion profile during laser surgery based on shock wave detection

    NASA Astrophysics Data System (ADS)

    Bay, Erwin; Dean Ben, Xosé Luis; Pang, Genny A.; Douplik, Alexandre; Razansky, Daniel

    2014-03-01

    Lack of sensory feedback during laser surgery prevents surgeons from keeping track of the exact lesion profile and cutting depth. As a result, duration and complexity of the treatments are significantly increased. In this study we propose a new method for enabling three-dimensional tracking of the exact lesion profile, based on detection of shock waves emanating from the ablated tissue and subsequent reconstruction of the incision location using time-of-flight data obtained from multiple acoustic detectors. Ablation was performed in fresh bovine tissue samples using a Q-switched Nd-YAG laser, delivering 8 ns duration 150mJ pulses at a wavelength of 1064nm and repetition rate of 5Hz. The beam was focused by a 50mm lens on the tissue surface, which resulted in a deep cut of up to 9mm depth. The generated shock waves were detected using a spherical matrix ultrasonic array. The exact cutting profile was subsequently rendered by reconstructing the origin of shockwaves detected during the entire procedure. Different combinations of the detector positions were considered with respect to the resulting reconstruction quality. It was observed that, by utilizing at least 12 detection elements, the lesion profile could be characterized with high accuracy in all three dimensions, which was confirmed by histological evaluations. The proposed method holds promise for delivering highly precise and accurate real-time feedback during laser surgeries.

  19. 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.

  20. 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

  1. IgG4-related Disease: A Mass Lesion in the Intrarenal Sinus near the Renal Pelvis.

    PubMed

    Inenaga, Jun-Ichi; Ueno, Toshiharu; Kawada, Masahiro; Imafuku, Aya; Mise, Koki; Sumida, Keiichi; Hiramatsu, Rikako; Hasegawa, Eiko; Hayami, Noriko; Suwabe, Tatsuya; Hoshino, Junichi; Sawa, Naoki; Takaichi, Kenmei; Fujii, Takeshi; Ohashi, Kenichi; Okaneya, Toshikazu; Ubara, Yoshifumi

    2015-01-01

    A 52-year-old Japanese woman was admitted to our hospital with the renal pelvic mass lesion detected on a health screening examination. The surgical specimen contained a mass exhibiting the histological features of immunoglobulin (Ig)G4-related disease, including lymphoplasmacytic infiltration and sclerosis with numerous IgG4-producing plasma cells. Postoperatively, an elevation of the serum IgG4 level was confirmed at 403 mg/dL; however, there was no evidence of tubulointerstitial nephritis or glomerulopathy, including membranous nephropathy, and the urothelium of the renal pelvis was intact without inflammation. We herein report this case in which IgG4-related disease of the renal pelvic region presented with a mass lesion in the intrarenal sinus near the renal pelvis, not 'pyelitis' (as described by Stone). PMID:26234232

  2. Detection of multiple sclerosis lesions in MRIs with an SVM classifier

    NASA Astrophysics Data System (ADS)

    D'Addabbo, Annarita; Ancona, Nicola; Blonda, Palma N.; De Blasi, Roberto A.

    2003-05-01

    The purpose of this paper is to test the effectiveness of a Support Vector Machine (SVM) classifier, with gaussian kernel function, in the automatic detection of small lesions from Magnetic Resonance Images (MRIs) of a patientt affected by multiple sclerosis. The data set consists of Proton Density, T2 (the spin-spin relaxation time) Spin-Echo images and a three-dimensional T1-weighted gradient echo sequence, called Magnetization-Prepared RApid Gradient Echo, that can be generated from contiguous and very thin sections, allowing detection of small lesions typically affected by partial volume effects and intersection gaps in T1 weighted Spin-Echol sequences. In this context of classification, SVM with Gaussian kernel function exhibited a good classification accuracy, higher than accuracies obtained, on the same data set, with a traditional RBF, confirming its high generalization capability and its effectiveness when applied to low-dimensional multi-spectral images.

  3. 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.

  4. 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

    2015-10-01

    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. PMID:26389637

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. The clinical characteristics and prognosis of lesions with in-stent eccentric tissue proliferation and strong signal attenuation detected by optical coherence tomography.

    PubMed

    Suzuki, Nobuaki; Kozuma, Ken; Kyono, Hiroyuki; Nakaya, Hiroaki; Nishide, Seiji; Mitsui, Miho; Nara, Yugo; Kawashima, Hideyuki; Nomura, Takahiro; Yamamoto, Hirosada; Sasajima, Yuko; Kondo, Fukuo; Isshiki, Takaaki

    2016-07-01

    There are still some patients who require repeat revascularization despite of drug-eluting stent (DES) implantation. The present study aimed to investigate the relationship between optical coherence tomography (OCT) findings and recurring target lesion revascularization (TLR) after percutaneous coronary intervention (PCI) for in-stent restenosis (ISR). We reviewed 50 patients (54 coronary lesions) who underwent PCI for ISR, which included 25 DES-ISR lesions. The PCI strategy depended on the interventionalist's discretion, and DES implantation was performed for 38 (70 %) lesions. Tissue characteristics were assessed qualitatively and quantitatively using the frame showing maximal lumen narrowing (minimal lumen area). In qualitative analysis, OCT detected coexistence of eccentric tissue proliferation and strong signal attenuation (ESA). ESA was observed in six lesions (11 %) in five patients (10 %). Hemodialysis (80 vs. 20 %, p = 0.013) and DES-ISR (100 vs. 40 %, p = 0.0069) were significantly more frequent in ESA patients/lesions than in others. One-year follow-up revealed that re-TLR was more frequently performed for ESA lesions (83 vs. 8 %, p = 0.0002). The findings reveal that ESA detected in OCT images of ISR is related to TLR after PCI for DES-ISR especially in patients undergoing maintenance hemodialysis. PMID:26608163

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

    PubMed

    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. PMID:27587136

  11. Red Lesion Detection Using Dynamic Shape Features for Diabetic Retinopathy Screening.

    PubMed

    Seoud, Lama; Hurtut, Thomas; Chelbi, Jihed; Cheriet, Farida; Langlois, J M Pierre

    2016-04-01

    The development of an automatic telemedicine system for computer-aided screening and grading of diabetic retinopathy depends on reliable detection of retinal lesions in fundus images. In this paper, a novel method for automatic detection of both microaneurysms and hemorrhages in color fundus images is described and validated. The main contribution is a new set of shape features, called Dynamic Shape Features, that do not require precise segmentation of the regions to be classified. These features represent the evolution of the shape during image flooding and allow to discriminate between lesions and vessel segments. The method is validated per-lesion and per-image using six databases, four of which are publicly available. It proves to be robust with respect to variability in image resolution, quality and acquisition system. On the Retinopathy Online Challenge's database, the method achieves a FROC score of 0.420 which ranks it fourth. On the Messidor database, when detecting images with diabetic retinopathy, the proposed method achieves an area under the ROC curve of 0.899, comparable to the score of human experts, and it outperforms state-of-the-art approaches. PMID:26701180

  12. 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.

  13. Bone scintigraphy and the added value of SPECT (single photon emission tomography) in detecting skeletal lesions.

    PubMed

    Savelli, G; Maffioli, L; Maccauro, M; De Deckere, E; Bombardieri, E

    2001-03-01

    Skeletal metastases are one of the major clinical problems for the oncologist. Over the last several decades bone scintigraphy has been used extensively in detecting bone involvement since it can provide information about disease location, prognosis and the effectiveness of treatment. Bone scan offers the advantage of total body examination, and images bone lesions earlier than other techniques. In this paper the main clinical problems related to the most common applications of bone scan in breast, prostate, lung cancer and other tumours are discussed. The experience carried out at the National Cancer Institute of Milan by using bone SPECT to detect single bone metastases is reported. One hundred and eighteen patients with bone metastases (from different tumour types: breast, lung, prostate, lymphomas, etc.) were studied by planar scintigraphy, SPECT and other radiological modalities (CT, MRI or X-rays). The overall performances of bone SPECT were sensitivity: 90.5% (19/21), specificity 92.8% (90/97), positive predictive value 73% (19/26), negative predictive value 97.8% (90/92), accuracy 92.4% (109/118). Considering breast cancer, the most frequent pathology in our series, and the lumbar spinal tract, the most common skeletal segment involved, the figures of merit of SPECT were: sensitivity 100% (4/4), specificity 95.3% (41/43), positive predictive value 66.7% (4/6), negative predictive value 100% (41/41), accuracy 95.7% (45/47). In conclusion bone SPECT showed very good performances, in particular improving the predictive value of planar scan in the diagnosis of vertebral metastases. PMID:11456373

  14. 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.

  15. Analysis of geometrical relations between multiple sclerosis lesions and brain vasculature

    NASA Astrophysics Data System (ADS)

    Kozinska, Dorota E.; Holland, Christopher; Krissian, Karl; Westin, Carl-Fredrik; Guttmann, Charles R. G.

    2004-04-01

    Due to histological evidence of the fundamental role of the cerebral vessels in white matter abnormalities, recently there has been an increased interest in analyzing the relationship between brain white matter lesions in multiple sclerosis (MS) and brain vasculature. We developed a method for visualization and measurement of geometrical relationships between MS lesions and the brain vessels imaged with magnetic resonance (MR) imaging techniques. Using MR images we create surface models of lesions and vessels that constitute a base for quantitative analysis. In this work we analyze correlation between basic lesion geometrical characteristics and two features: 1) distances to vessels, and 2) vessel caliber. For the former, we compute a distance map from the vessel structure, such that each voxel stores its distance vector to the closest vessel. This allows the measurements of Euclidean distances to the closest vessels. For the latter, we compute a radius map in which each voxel stores the radius of its closest vessel. It is used to measure distribution of lesions with respect to the vessel caliber. We compute and analyze relations between the basic geometrical characteristics of lesions and the closest vessels locations and calibers. To demonstrate the feasibility of the developed technique we present results from the study of 3 MS cases.

  16. 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.

  17. 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

  18. Role of Breast Ultrasound for the Detection and Differentiation of Breast Lesions

    PubMed Central

    Madjar, Helmut

    2010-01-01

    Summary Diagnosis of breast cancer has been widely improved since the development of high-resolution ultrasound equipment. In the past, ultrasound was only considered useful for the diagnosis of cysts. Meanwhile, it improves the differential diagnosis of benign and malignant lesions, local preoperative staging and guided interventional diagnosis. In dense breasts, mammography has limited sensitivity. Furthermore, women with dense parenchyma have a highly increased risk of breast cancer development. Ultrasound is useful to examine dense breast tissue. Recent studies have shown that the detection of small cancers with high-resolution ultrasound is increased by 3–4 cancers per 1,000 women without clinical or mammographic abnormalities. Furthermore, stage distribution is similar between mammographically and sonographically detected carcinomas. Ultrasound is routinely used for curative diagnosis, to overcome the limitations of mammography. However, within the mammographic screening in Germany, breast density is not considered as important. Ultrasound is only used if a suspicious lesion is detected by mammography. Interestingly, 2 years ago, a screening project started in Austria in which ultrasound is always added in cases of dense breasts. Preliminary data show that the detection of additional carcinomas is increased in the same order as shown in previous studies. Therefore, an improved cancer detection and differentiation can be expected with high-resolution ultrasound. PMID:20847824

  19. 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

  20. 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

  1. 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

  2. Multiple sclerosis lesion quantification in MR images by using vectorial scale-based relative fuzzy connectedness

    NASA Astrophysics Data System (ADS)

    Zhuge, Ying; Udupa, Jayaram K.; Nyul, Laszlo G.

    2004-05-01

    This paper presents a methodology for segmenting PD- and T2-weighted brain magnetic resonance (MR) images of multiple sclerosis (MS) patients into white matter (WM), gray matter (GM), cerebrospinal fluid (CSF), and MS lesions. For a given vectorial image (with PD- and T2-weighted components) to be segmented, we perform first intensity inhomogeneity correction and standardization prior to segmentation. Absolute fuzzy connectedness and certain morphological operations are utilized to generate the brain intracranial mask. The optimum thresholding method is applied to the product image (the image in which voxel values represent T2 value x PD value) to automatically recognize potential MS lesion sites. Then, the recently developed technique -- vectorial scale-based relative fuzzy connectedness -- is utilized to segment all voxels within the brain intracranial mask into WM, GM, CSF, and MS lesion regions. The number of segmented lesions and the volume of each lesion are finally output as well as the volume of other tissue regions. The method has been tested on 10 clinical brain MRI data sets of MS patients. An accuracy of better than 96% has been achieved. The preliminary results indicate that its performance is better than that of the k-nearest neighbors (kNN) method.

  3. 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. PMID:24333829

  4. Phase-Sensitive Inversion-Recovery MRI Improves Longitudinal Cortical Lesion Detection in Progressive MS

    PubMed Central

    Farrell, Colleen; Fabian, Michelle; Howard, Jonathan; Riley, Claire; Miller, Aaron; Lublin, Fred; Inglese, Matilde

    2016-01-01

    Previous studies comparing phase sensitive inversion recovery (PSIR) to double inversion recovery (DIR) have demonstrated that use of PSIR improves cross-sectional in vivo detection of cortical lesions (CL) in multiple sclerosis. We studied the utility of PSIR in detection/characterization of accrual of CL over time in a 1-year longitudinal study in primary progressive multiple sclerosis (PPMS) compared to DIR. PSIR and DIR images were acquired with 3T magnetic resonance imaging (MRI) in 25 patients with PPMS and 19 healthy controls at baseline, and after 1 year in 20 patients with PPMS. CL were classified as intracortical, leucocortical or juxtacortical. Lesion counts and volumes were calculated for both time points from both sequences and compared. Correlations with measures of physical and cognitive disability were determined as well as new CL counts and volumes. Compared to DIR, PSIR led to detection of a higher number of CL involving a larger proportion of patients with PPMS both cross-sectionally (p = 0.006, 88%) and longitudinally (p = 0.007, 95%), and led to the reclassification of a third of CL seen on DIR at each time point. Interestingly, PSIR was more sensitive to new CL accumulation over time compared to DIR. PSIR is a promising technique to monitor cortical damage and disease progression in patients with PPMS over a short-term follow-up. PMID:27002529

  5. 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

  6. 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.

  7. 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.

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

    DOEpatents

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

    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.

  9. 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.

  10. Chapter 17. Aortic, coronary, and myocardial lesions in relation to various factors

    PubMed Central

    Kagan, A. R.

    1976-01-01

    The relative extent of raised and calcified coronary aortic lesions, prevalence of coronary stenosis and of fresh and old myocardial infarction, and mean heart weight were expressed on a continuous scale for 4 disease groups (coronary heart disease, cerebral infarction/haemorrhage, hypertension/diabetes, cancer). Within these groups the relative position for each of the lesions was calculated by subgroups of disease in order to show the elevating or depressing effect of hypertension, diabetes, obesity, and combinations of disease. The strength of association between 33 factors (town 5, disease 24, obesity, heart weight, age, and sex) and the lesions was calculated. An analysis of variance was carried out and the proportion of the variance of the different lesions accounted for by town, disease, etc., is shown. The extent of raised aortic lesions is strongly associated with age and hypertension. It is positively associated with coronary heart disease and inversely associated with cancer. Town factors have a small positive association which is larger than that due to obesity. 33 factors taken together account for 50% of the variance. Age alone accounts for 37% and sex for only 0.3%. The extent of calcified aortic lesion is strongly associated with age, town, hypertension, coronary heart disease and diabetes mellitus. It is inversely associated with cancer, more strongly in cancer of the bronchus and the liver than in other cancers. It is inversely associated with obesity. 33 factors together account for 30% of the variance and age alone accounts for about 13%. The extent of raised coronary lesions is strongly associated with age, coronary heart disease, sex, diabetes mellitus, hypertension and obesity. It is inversely associated with cancer, more strongly in cancer of the prostate and the liver than in other cancers. Town factors have a small association. 33 factors taken together account for about 43% of the variance. Age alone accounts for 25%. The extent of

  11. Focal Cortical Lesion Detection in Multiple Sclerosis: 3T DIR versus 7T FLASH-T2*

    PubMed Central

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

    2014-01-01

    Purpose To evaluate the inter-rater agreement of cortical lesion detection using 7T FLASH-T2* and 3T DIR sequences. Materials and Methods Twenty-six patients with multiple sclerosis were scanned on a human 7T (Sidemen’s) and 3T MRI (TIM Trio, Sidemen’s) to acquire 3T DIR/MEMPR and 7T FLASH-T2* sequences. Four independent reviewers scored and categorized cortical lesions in the bilateral pre-central 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. Results Inter-rater agreement at 7T was excellent compared to 3T (k=0.97 vs. 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%). Conclusion 7T FLASH-T2* detects more cortical—particularly subpial—lesions compared to 3T DIR. In the absence of DIR/post-mortem data, 7T FLASH-T2* is a suitable gold-standard instrument and should be incorporated into future consensus guidelines. PMID:22045554

  12. High reproducibility of histological diagnosis of human papillomavirus-related intraepithelial lesions of the anal canal.

    PubMed

    Roberts, Jennifer M; Jin, Fengyi; Thurloe, Julia K; Biro, Clare; Poynten, Isobel M; Tabrizi, Sepehr N; Fairley, Christopher K; Templeton, David J; Carr, Andrew D; Garland, Suzanne M; Hillman, Richard J; Cornall, Alyssa M; Grulich, Andrew E; Farnsworth, Annabelle

    2015-06-01

    In a natural history study of anal human papillomavirus (HPV) infection and HPV-related lesions, we examined the reproducibility of histological high-grade squamous intraepithelial lesion (HSIL). Three expert anogenital pathologists share the reporting of histological specimens from the Study of the Prevention of Anal Cancer (SPANC), utilising Lower Anogenital Squamous Terminology (LAST) criteria. In total, 194 previously reported biopsies were randomly chosen within diagnostic strata [50 HSIL-anal intraepithelial neoplasia (AIN) 3; 45 HSIL-AIN 2; 49 'flat' low-grade squamous intraepithelial lesion (LSIL); 50 'exophytic' LSIL; and 50 negative for squamous intraepithelial lesion] and reviewed by each of these three pathologists. Consensus was defined as agreement between at least two review diagnoses, using a binary classification of HSIL and non-HSIL, or if consensus was not obtained in this way, it was achieved through a multiheader microscope session by the three pathologists. We found very high agreement between original and consensus diagnoses (Kappa = 0.886) and between each pathologist's review and consensus (Kappas = 0.926, 0.917 and 0.905). Intra-observer agreement for the three pathologists was 0.705, 1.000 and 0.854. This high level of diagnostic reproducibility indicates that the findings of SPANC should be robust and provide reliable information about HPV-related anal canal disease. PMID:25938361

  13. 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.

  14. Hybrid capture II, a new sensitive test for human papillomavirus detection. Comparison with hybrid capture I and PCR results in cervical lesions.

    PubMed Central

    Clavel, C; Masure, M; Putaud, I; Thomas, K; Bory, J P; Gabriel, R; Quereux, C; Birembaut, P

    1998-01-01

    AIM: To test a new assay for the detection of human papillomavirus (HPV) DNA, hybrid capture II (HC II), compared with the previous commercialized hybrid capture I (HC I) and polymerase chain reaction (PCR) results on cervical scrapes from fresh cone excision biopsy samples. METHODS: The three methods were used on cervical scrapes from 42 fresh cone excision biopsy samples. There were nine metaplastic and inflammatory lesions, five low grade lesions, and 28 high grade lesions. PCR was performed using the general primers GP5+/GP6+. The viral load of high risk HPV DNA was estimated by the ratio of relative light units to positive control values in the samples. RESULTS: The sensitivity of HC I for the detection of high grade lesions was 71.4%, while it was 92.8% for HC II and 96.4% for the PCR. Considering only the absence of detectable cervical in situ neoplasia, the specificity was 88.9% for HC I, 66.7% for HC II, and 66.7% for PCR. With HC II, for a ratio of cervical sample to normal control of > 200, the sensitivity for the detection of high grade lesion was only 34.6% with a specificity of 66.7%. CONCLUSIONS: HPV detection with the HC II assay is more sensitive than the previous HC I and represents a more convenient and easier test than PCR for routine use. Nevertheless the viral load estimated with this test cannot be a reliable predictive indicator of high grade lesions. PMID:10023335

  15. Detection of interproximal demineralized lesions on human teeth in vitro using frequency-domain infrared photothermal radiometry and modulated luminescence.

    PubMed

    Jeon, Raymond J; Matvienko, Anna; Mandelis, Andreas; Abrams, Stephen H; Amaechi, Bennett T; Kulkarni, Gajanan

    2007-01-01

    Frequency-domain photothermal radiometry (FD-PTR or PTR) is used to detect mechanical holes and demineralized enamel in the interproximal contact area of extracted human teeth. Thirty-four teeth are used in a series of experiments. Preliminary tests to detect mechanical holes created by dental burs and 37% phosphoric acid etching for 20 s on the interproximal contact points show distinct differences in the signal. Interproximal contact areas are demineralized by using a partially saturated acidic buffer system. Each sample pair is examined with PTR before and after micromachining or treating at sequential treatment periods spanning 6 h to 30 days. Dental bitewing radiographs showed no sign of demineralized lesion even for samples treated for 30 days. Microcomputer tomography (micro-CT), transverse microradiography (TMR), and scanning electron microscopy (SEM) analyses are performed. Although micro-CT and TMR measured mineral losses and lesion depths, only SEM surface images showed visible signs of treatment because of the minimal extent of the demineralization. However, the PTR amplitude increased by more than 300% after 80 h of treatment. Therefore, PTR is shown to have sufficient contrast for the detection of very early interproximal demineralized lesions. The technique further exhibits excellent signal reproducibility and consistent signal changes in the presence of interproximal demineralized lesions, attributes that could lead to PTR as a reliable probe to detect early interproximal demineralization lesions. Modulated luminescence is also measured simultaneously, but it shows a lower ability than PTR to detect these interproximal demineralized lesions. PMID:17614736

  16. Detection of Circulating Pancreas Epithelial Cells in Patients with Pancreatic Cystic Lesions

    PubMed Central

    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.

    2014-01-01

    Hematogenous dissemination is thought to be a late event in cancer progression. We showed recently that pancreas cells can be detected in the bloodstream before tumor formation, in a genetic model of pancreatic ductal adenocarcinoma (PDAC). To confirm these findings in humans, we used microfluidic geometrically enhanced immunocapture to detect circulating pancreas epithelial cells (CECs) in patient blood samples. We captured >3 CECs/ml in 7 of 21 (33%) of patients with cystic lesions and no clinical diagnosis of cancer (Sendai criteria negative), 8 of 11 (73%) with PDAC, 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 develop, which might be used in risk assessment. PMID:24333829

  17. N-NITROSODIETHYLAMINE-INDUCED HEPATOCARCINOGENESIS IN ESTUARINE SHEEPSHEAD MINNOW ('CYPRINODON VARIEGATUS'): NEOPLASMS AND RELATED LESIONS COMPARED WITH MAMMALIAN LESIONS

    EPA Science Inventory

    Groups of estuarine sheepshead minnows (Cyprinodon variegatus) were exposed to 50-60 mg/l N-nitrosodiethylamine (DENA) for five to six weeks. Exposure was stopped and the fish were then transferred to clean, flowing seawater. Induced liver lesions were studied in periodic samples...

  18. 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

  19. Environmental factors in Helicobacter pylori-related gastric precancerous lesions in Venezuela.

    PubMed

    Kato, Ikuko; Vivas, Jorge; Plummer, Martyn; Lopez, Gladys; Peraza, Simon; Castro, Dennis; Sanchez, Victor; Cano, Elsa; Andrade, Olga; Garcia, Rita; Franceschi, Silvia; Oliver, Walter; Muñoz, Nubia

    2004-03-01

    Although Helicobacter pylori (HP) infection has been acknowledged to play an etiological role in gastric carcinogenesis, its relatively weak association particularly in developing countries suggests critical roles of cofactors. Among a population with an extremely high prevalence of HP infection ( approximately 95%) in Venezuela, we examined the relationship of household characteristics, smoking, alcohol drinking, dietary consumption, and plasma nutrient levels with the prevalence of three different stages of gastric precancerous lesions, chronic atrophic gastritis (AG; n = 337), intestinal metaplasia (IM; n = 551), and dysplasia (n = 157), in comparison with those without any of these lesions (n = 1154). Length of refrigerator use was marginally inversely associated with the prevalence of the precursor lesions studied. The association was most pronounced for AG followed by dysplasia. On the other hand, smoking status was a significant predictor for IM and dysplasia. Those smoking >/=>10 cigarettes/day had 1.8-fold risk of IM and 3.6-fold risk of dysplasia compared with never smokers. There were no associations with alcohol consumption. When six food groups known to be associated with stomach cancer risk in Venezuela were tested, the prevalence of these lesions progressively increased with increasing starchy vegetable consumption and decreasing fresh fruit/fruit juice consumption. The association with fruits was more evident for dysplasia and AG and that with starchy vegetables for IM and AG. However, there were no inverse associations with plasma antioxidant vitamins. These findings offer important public health implications in preventing progression of HP-associated gastric precancerous lesions in high-risk populations. PMID:15006925

  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. High-frequency mode conversion technique for stiff lesion detection with magnetic resonance elastography (MRE).

    PubMed

    Mariappan, Yogesh K; Glaser, Kevin J; Manduca, Armando; Romano, Anthony J; Venkatesh, Sudhakar K; Yin, Meng; Ehman, Richard L

    2009-12-01

    A novel imaging technique is described in which the mode conversion of longitudinal waves is used for the qualitative detection of stiff lesions within soft tissue using magnetic resonance elastography (MRE) methods. Due to the viscoelastic nature of tissue, high-frequency shear waves attenuate rapidly in soft tissues but much less in stiff tissues. By introducing minimally-attenuating longitudinal waves at a significantly high frequency into tissue, shear waves produced at interfaces by mode conversion will be detectable in stiff regions, but will be significantly attenuated and thus not detectable in the surrounding soft tissue. This contrast can be used to detect the presence of stiff tissue. The proposed technique is shown to readily depict hard regions (mimicking tumors) present in tissue-simulating phantoms and ex vivo breast tissue. In vivo feasibility is demonstrated on a patient with liver metastases in whom the tumors are readily distinguished. Preliminary evidence also suggests that quantitative stiffness measurements of stiff regions obtained with this technique are more accurate than those from conventional MRE because of the short shear wavelengths. This rapid, qualitative technique may lend itself to applications in which the localization of stiff, suspicious neoplasms is coupled with more sensitive techniques for thorough characterization. PMID:19859936

  2. Diffusion-Weighted Imaging with Two Different b-Values in Detection of Solid Focal Liver Lesions

    PubMed Central

    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. PMID:27019851

  3. Comparison of 64-Detector CT Colonography and Conventional Colonoscopy in the Detection of Colorectal Lesions

    PubMed Central

    Devir, Cigdem; Kebapci, Mahmut; Temel, Tuncer; Ozakyol, Aysegul

    2016-01-01

    Background: Colon cancer is a leading cause of morbidity and mortality in developed countries. The early detection of colorectal cancer using screening programs is important for managing early-stage colorectal cancers and polyps. Modalities that allow examination of the entire colon are conventional colonoscopy, double contrast barium enema examination and multi-detector computed tomography (MDCT) colonography. Objectives: To compare CT colonography and conventional colonoscopy results and to evaluate the accuracy of CT colonography for detecting colorectal lesions. Patients and Methods: In a prospective study performed at Gastroenterology and Radiology Departments of Medical Faculty of Eskisehir Osmangazi University, CT colonography and colonoscopy results of 31 patients with family history of colorectal carcinoma, personal or family history of colorectal polyps, lower gastrointestinal tract bleeding, change in bowel habits, iron deficiency anemia and abdominal pain were compared. Regardless of the size, CT colonography and conventional colonoscopy findings for all the lesions were cross - tabulated and the sensitivity, specificity, and positive and negative predictive values were calculated. To assess the agreement between CT colonography and conventional colonoscopy examinations, the Kappa coefficient of agreementt was used. Statistical analysis was performed by SPSS ver 15.0. Results: Regardless of the size, MDCT colonography showed 83% sensitivity and 95% specificity, with a positive predictive value of 95% and a negative predictive value of 83% for the detection of colorectal polyps and masses. MDCT colonography displayed 92% sensitivity and 95% specificity, with a positive predictive value of 92% and a negative predictive value of 95% for polyps ≥ 10 mm. For polyps between 6mm and 9 mm, MDCT colonography displayed 75% sensitivity and 100% specificity, with a positive predictive value of 100% and a negative predictive value of 90%. For polyps ≤ 5 mm MDCT

  4. 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.

  5. Quantitative evaluation of automatic methods for lesions detection in breast ultrasound images

    NASA Astrophysics Data System (ADS)

    Marcomini, Karem D.; Schiabel, Homero; Carneiro, Antonio Adilton O.

    2013-02-01

    Ultrasound (US) is a useful diagnostic tool to distinguish benign from malignant breast masses, providing more detailed evaluation in dense breasts. Due to the subjectivity in the images interpretation, computer-aid diagnosis (CAD) schemes have been developed, increasing the mammography analysis process to include ultrasound images as complementary exams. As one of most important task in the evaluation of this kind of images is the mass detection and its contours interpretation, automated segmentation techniques have been investigated in order to determine a quite suitable procedure to perform such an analysis. Thus, the main goal in this work is investigating the effect of some processing techniques used to provide information on the determination of suspicious breast lesions as well as their accurate boundaries in ultrasound images. In tests, 80 phantom and 50 clinical ultrasound images were preprocessed, and 5 segmentation techniques were tested. By using quantitative evaluation metrics the results were compared to a reference image delineated by an experienced radiologist. A self-organizing map artificial neural network has provided the most relevant results, demonstrating high accuracy and low error rate in the lesions representation, corresponding hence to the segmentation process for US images in our CAD scheme under tests.

  6. 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.

  7. Detection of Helicobacter pylori in various oral lesions by nested polymerase chain reaction (PCR).

    PubMed

    Mravak-Stipetić, M; Gall-Troselj, K; Lukac, J; Kusić, Z; Pavelić, K; Pavelić, J

    1998-01-01

    Nested PCR was used for the detection of Helicobacter pylori DNA in specimens collected from seven different topographic sites in the oral cavity. Out of 161 patients, only 21 (13.04%) were positive. There was no correlation between H. pylori status and patient diagnosis and age. No preferential site for bacterial colonization was found in the oral cavity, nor was an association established between a bacterial presence and ulcerated versus non-ulcerated lesions. The results indicate that the oral mucosa does not appear to represent a preferred site of colonization for H. pylori. Furthermore, the evidence presented in this paper suggests that H. pylori is not pathogenic in the oral cavity, nor is it associated with common oral pathologic processes. PMID:9466726

  8. Investigation of a light imaging system to detect small lesions in thick tissues

    NASA Astrophysics Data System (ADS)

    Wist, Abund O.; Moon, Peter; Herr, Steven L.; Fatouros, Panos P.

    1995-02-01

    A light imaging system is being developed which can at this time detect and characterize small lesions on the surface and deep inside a tooth or tissue. It depends on the existence of light photons which can fully traverse a tooth in a straight path and therefore can make -- similar to x rays -- a clear shadow of a pathology on the receiver. To observe the very weak, transmitted, unscattered light rays a special patented system has been developed using collimated, narrow light beams and a highly sensitive, post collimated receiver which are rasterscanned over the entire sample. The image can be transferred in analog form to a film or observed after digitization on a 256 grayshade monitor. The light image can be observed in a regular or slower high sensitivity mode.

  9. Detection of colonic malignant lesions by digital imaging of UV laser-induced autofluorescence.

    PubMed

    Chwirot, B W; Michniewicz, Z; Kowalska, M; Nussbeutel, J

    1999-03-01

    The objective of our study was to investigate whether digital imaging of autofluorescence could be applied in the detection of colonic malignancies. Autofluorescence was excited with a 325 nm line from a He-Cd laser. Images were recorded in vitro in six spectral bands. The material for study was 50 resected specimens for which images of 64 areas were recorded. The main result is the observation that for a majority of malignant and premalignant lesions the intensity of autofluorescence was lower than for the corresponding normal mucosa in all of the spectral bands selected for imaging. The spectral bands centered around 440 nm and 475 nm seem to be most promising in terms of possible future clinical applications. PMID:10089825

  10. 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

  11. 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. PMID:23278908

  12. Blue Mode Imaging may Improve the Detection and Visualization of Small-Bowel Lesions: A Capsule Endoscopy Study

    PubMed Central

    Abdelaal, Usama M.; Morita, Eijiro; Nouda, Sadaharu; Kuramoto, Takanori; Miyaji, Katsuhiko; Fukui, Hideo; Tsuda, Yasuhiro; Fukuda, Akira; Murano, Mitsuyuki; Tokioka, Satoshi; Umegaki, Eiji; Arfa, Usama A.; Higuchi, Kazuhide

    2015-01-01

    Background/Aims: Diagnostic miss rate and time consumption are the two challenging limitations of small-bowel capsule endoscopy (SBCE). In this study, we aimed to know whether using of the blue mode (BM) combined with QuickView (QV) at a high reviewing speed could influence SBCE interpretation and accuracy. Materials and Methods: Seventy CE procedures were totally reviewed in four different ways; (1) using the conventional white light, (2) using the BM, [on a viewing speed at 10 frames per second (fps)], (3) using white light, and (4) using the BM (on a viewing speed at 20 fps). In study A, the results of (1) were compared with those of (2), and in study B, the results of (3) and (4) were separately compared with those of (1). Results: In study A, the total number of the vascular (P < 0.001) and the inflammatory lesions (P = 0.005) detected by BM was significantly higher than that detected by the white light. No lesion was found using the white light that was not detected by the BM. Moreover, the BM highly improved the image quality of all the vascular lesions and the erythematous ones from the nonvascular lesions. In study B, the total number of only the vascular lesions, detected by the BM on a rapid speed of viewing at 20 fps was significantly higher than that detected by the white light (P = 0.035). However, the true miss rate for the BM was 4%. Conclusion: BM imaging is a new method that improved the detection and visualization of the vascular and erythematous nonvascular lesions of SB as compared with the conventional white light imaging. Using of the BM at a slow viewing speed, markedly reduced the diagnostic miss rate of CE. PMID:26655139

  13. 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

  14. Relating multi-sequence longitudinal intensity profiles and clinical covariates in incident multiple sclerosis lesions

    PubMed Central

    Sweeney, Elizabeth M.; Shinohara, Russell T.; Dewey, Blake E.; Schindler, Matthew K.; Muschelli, John; Reich, Daniel S.; Crainiceanu, Ciprian M.; Eloyan, Ani

    2015-01-01

    The formation of multiple sclerosis (MS) lesions is a complex process involving inflammation, tissue damage, and tissue repair — all of which are visible on structural magnetic resonance imaging (MRI) and potentially modifiable by pharmacological therapy. In this paper, we introduce two statistical models for relating voxel-level, longitudinal, multi-sequence structural MRI intensities within MS lesions to clinical information and therapeutic interventions: (1) a principal component analysis (PCA) and regression model and (2) function-on-scalar regression models. To do so, we first characterize the post-lesion incidence repair process on longitudinal, multi-sequence structural MRI from 34 MS patients as voxel-level intensity profiles. For the PCA regression model, we perform PCA on the intensity profiles to develop a voxel-level biomarker for identifying slow and persistent, long-term intensity changes within lesion tissue voxels. The proposed biomarker's ability to identify such effects is validated by two experienced clinicians (a neuroradiologist and a neurologist). On a scale of 1 to 4, with 4 being the highest quality, the neuroradiologist gave the score on the first PC a median quality rating of 4 (95% CI: [4,4]), and the neurologist gave the score a median rating of 3 (95% CI: [3,3]). We then relate the biomarker to the clinical information in a mixed model framework. Treatment with disease-modifying therapies (p < 0.01), steroids (p < 0.01), and being closer to the boundary of abnormal signal intensity (p < 0.01) are all associated with return of a voxel to an intensity value closer to that of normal-appearing tissue. The function-on-scalar regression model allows for assessment of the post-incidence time points at which the covariates are associated with the profiles. In the function-on-scalar regression, both age and distance to the boundary were found to have a statistically significant association with the lesion intensities at some time point

  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. Imaging of oxidation-specific epitopes with targeted nanoparticles to detect high-risk atherosclerotic lesions: progress and future directions.

    PubMed

    Briley-Saebo, Karen; Yeang, Calvin; Witztum, Joseph L; Tsimikas, Sotirios

    2014-11-01

    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 non-invasively 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

  17. Cardiac motion compensation and resolution modeling in simultaneous PET-MR: a cardiac lesion detection study

    PubMed Central

    Petibon, Y; Ouyang, J; Zhu, X; Huang, C; Reese, T G; Chun, S Y; Li, Q; El Fakhri, G

    2013-01-01

    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 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 detectability

  18. 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

  19. 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. PMID:19034476

  20. Diagnostic accuracy of cone beam computed tomography compared with intraoral radiography for the detection of noncavitated occlusal carious lesions.

    PubMed

    Krzyżostaniak, Joanna; Surdacka, Anna; Kulczyk, Tomasz; Dyszkiewicz-Konwińska, Marta; Owecka, Magdalena

    2014-01-01

    The aim of this study was to evaluate the accuracy of cone beam computed tomography (CBCT) in the detection of noncavitated occlusal caries lesions and to compare this accuracy with that observed with conventional radiographs. 135 human teeth, 67 premolars and 68 molars with macroscopically intact occlusal surfaces, were examined by two independent observers using the CBCT system: NewTom 3G (Quantitative Radiology) and intraoral conventional film (Kodak Insight). The true lesion diagnosis was established by histological examination. The detection methods were compared by means of sensitivity, specificity, predictive values and accuracy. To assess intra- and interobserver agreement, weighted kappa coefficients were computed. Analyses were performed separately for caries reaching into dentin and for all noncavitated lesions. For the detection of occlusal lesions extending into dentin, sensitivity values were lower for film (0.45) when compared with CBCT (0.51), but the differences were not statistically significant (p > 0.19). For all occlusal lesions sensitivity values were 0.32 and 0.22, respectively, for CBCT and film. The specificity scores were high for both modalities. Interobserver agreement amounted to 0.93 for the CBCT system and to 0.87 for film. It was concluded that the use of the 9-inch field of view NewTom CBCT unit for the diagnosis of noncavitated occlusal caries cannot be recommended. PMID:24852420

  1. Inflammatory myofibroblastic tumor, inflammatory fibrosarcoma, and related lesions: an historical review with differential diagnostic considerations.

    PubMed

    Coffin, C M; Dehner, L P; Meis-Kindblom, J M

    1998-05-01

    The concept of the inflammatory myofibroblastic tumor (IMT) has evolved from an already perplexing pathological process, the inflammatory pseudotumor, which was initially recognized in the lung and regarded as a pseudoneoplasm, although its histological features resembled a spindle cell sarcoma. Despite the pathological findings and their apparent prognostic implications, most affected individuals regardless of the primary site have had favorable clinical outcomes. The designation of inflammatory pseudotumor came to be widely accepted, although these lesions were clearly tumors or masses that may or may not have been pseudoneoplasms. An aberrant or exaggerated response to tissue injury without an established cause has generally been favored as the pathogenesis of the inflammatory pseudotumor or IMT. Once the myofibroblast was identified and its function in tissue repair was established, this cell type was found in a variety of soft tissue lesions from nodular fasciitis to malignant fibrous histiocytoma. The myofibroblast was eventually recognized as the principal cell type in the inflammatory pseudotumor, which provided the opportunity to redesignate this tumor as IMT. Some of the clinical and pathological aspects of the IMT began to suggest the possibility that these lesions are more similar to neoplasms than a postinflammatory process. Another step in the evolution of the inflammatory pseudotumor and IMT occurred with the report of a mesenteric or retroperitoneal tumor with similar pathological features to the latter tumors but with more aggressive behavior to warrant an interpretation of malignancy as an inflammatory fibrosarcoma. The IMT and inflammatory fibrosarcoma appear to have many overlapping clinical and pathological features. These tumors are histogenetically related, and if they are separate entities, they are differentiated more by degrees than absolutes. The therapeutic approach to these tumors should relay primarily on surgical resection. Studies in

  2. 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. PMID:19963990

  3. 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

  4. Increased cortical grey matter lesion detection in multiple sclerosis with 7 T MRI: a post-mortem verification study.

    PubMed

    Kilsdonk, Iris D; Jonkman, Laura E; Klaver, Roel; van Veluw, Susanne J; Zwanenburg, Jaco J M; Kuijer, Joost P A; Pouwels, Petra J W; Twisk, Jos W R; Wattjes, Mike P; Luijten, Peter R; Barkhof, Frederik; Geurts, Jeroen J G

    2016-05-01

    The relevance of cortical grey matter pathology in multiple sclerosis has become increasingly recognized over the past decade. Unfortunately, a large part of cortical lesions remain undetected on magnetic resonance imaging using standard field strength. In vivo studies have shown improved detection by using higher magnetic field strengths up to 7 T. So far, a systematic histopathological verification of ultra-high field magnetic resonance imaging pulse sequences has been lacking. The aim of this study was to determine the sensitivity of 7 T versus 3 T magnetic resonance imaging pulse sequences for the detection of cortical multiple sclerosis lesions by directly comparing them to histopathology. We obtained hemispheric coronally cut brain sections of 19 patients with multiple sclerosis and four control subjects after rapid autopsy and formalin fixation, and scanned them using 3 T and 7 T magnetic resonance imaging systems. Pulse sequences included T1-weighted, T2-weighted, fluid attenuated inversion recovery, double inversion recovery and T2*. Cortical lesions (type I-IV) were scored on all sequences by an experienced rater blinded to histopathology and clinical data. Staining was performed with antibodies against proteolipid protein and scored by a second reader blinded to magnetic resonance imaging and clinical data. Subsequently, magnetic resonance imaging images were matched to histopathology and sensitivity of pulse sequences was calculated. Additionally, a second unblinded (retrospective) scoring of magnetic resonance images was performed. Regardless of pulse sequence, 7 T magnetic resonance imaging detected more cortical lesions than 3 T. Fluid attenuated inversion recovery (7 T) detected 225% more cortical lesions than 3 T fluid attenuated inversion recovery (Z = 2.22, P < 0.05) and 7 T T2* detected 200% more cortical lesions than 3 T T2* (Z = 2.05, P < 0.05). Sensitivity of 7 T magnetic resonance imaging was influenced by cortical lesion type: 100% for type

  5. Detection of a metastatic lesion and tiny yolk sac tumors in two teenage patients by FDG-PET: report of two cases.

    PubMed

    Takahashi, Masataka; Kanamori, Yutaka; Takahashi, Miwako; Momose, Toshimitsu; Iwanaka, Tadashi

    2014-10-01

    We herein report the efficacy of FDG-PET for detecting yolk sac tumors in two teenage patients. One patient had a rare bone metastasis and the other had tiny recurrent lesions at the mediastinum. Both lesions were difficult to detect by conventional diagnostic modalities. In contrast, FDG-PET was very effective for detecting these lesions. Furthermore, the SUVmax of the lesion reflected the tumor activity, which was also suggested by the fluctuating values of serum alpha-fetoprotein (AFP), an established marker of yolk sac tumors. FDG-PET may be a useful procedure to detect tiny and metastatic, pediatric yolk sac tumors. PMID:23801057

  6. Evaluation of orofacial lesions relating child abuse, Esfahan, Iran: A quantitative approach

    PubMed Central

    Nilchian, Firoozeh; Sadri, Leyli; Jabbarifar, Seyed Ebrahim; Saeidi, Alireza; Arbab, Leila

    2012-01-01

    Background: Family violence, including child abuse, neglect, and domestic violence, is a public health problem. The aim of this study was to provide data on prevalence and factors of Orofacial lesions relating child abuse in Iran to lend evidence to support preventing child abuse. Materials and Methods: The overall approach was a case-note review of children having child abuse note, recording by personnel of social services. Research ethical approval was sought from the Central social service organization. This study was conducted in Isfahan, Iran (2011). Result: The mean age of children, when abuse had been occurred was 8 years (SD = 1.68), and there were approximately an equal number of boys and girls. Children had a high physical experience (66.1%).Of these children, at least 60% sustained trauma to the face and mouth. Emotional abuse was 77.1%, neglect was 64.1%, and lower experience of sexual abuse which was 4.1%. There was a strong relationship between gender and abuser which shows girls have been affected by stepfathers (P = 0.001). Conclusion: Preliminary data suggest that there are strong evidence regarding the incidence of child abuse relating orofacial lesions which dentists should be aware of them. Future trials may draw on these useful baseline data to help their study design. PMID:23559953

  7. Descriptive data on cancerous lung lesions detected by auto-fluorescence bronchoscope: A five-year study

    PubMed Central

    Thakur, Asmitananda; Gao, Lin; Ren, Hui; Yang, Tian; Chen, Tianjun; Chen, Mingwei

    2012-01-01

    BACKGROUND: Auto-fluorescence bronchoscopy (AFB) has been used for the identification and localization of intra-epithelial pre-neoplastic and neoplastic lesions within the bronchus. OBJECTIVES: To determine the applicability of AFB for the detection and localization of precancerous and cancerous lesions, in addition to analyzing the morphologic presentation, their association to histological type and the variation between genders. METHODS: A five-year study involving 4983 patients, who underwent routine bronchoscopy [B] examination in a local tertiary teaching hospital, was done. The B examination was performed under intratracheal lidocaine, and samples were obtained using suitable approach. One thousand four hundred and eighty-five pathologically confirmed lung cancer patients were included in the study. The following parameters were studied: Morphological presentation, biopsy sites, histology. Differences between the groups were analyzed using Chi square test. RESULT: One thousand four hundred and eighty-five patients who had hyperplasia or neoplastic lesions were further confirmed as lung cancer pathologically. Lung cancer was more commonly found in the right lung (51.58% vs. 42.82%). The lesion occurred more frequently in the upper lobe than the lower lobe (44.17% vs. 22.42%). Male patients with squamous cell carcinoma showed upper lobe involvement more commonly, while the left main bronchus was more commonly involved in female patients. Adenocarcinoma mostly involved lesion of the upper lobe. Squamous cell carcinoma and small cell carcinoma were the major proliferative types (80.15% and 76.16% respectively). CONCLUSION: AFB is efficient in the detection of pre-invasive and invasive lung lesions. The morphological presentation is associated to the histological type. There is variation in the presentation and histology of cancerous lung lesions between genders. PMID:22347346

  8. IMaGe: Iterative Multilevel Probabilistic Graphical Model for Detection and Segmentation of Multiple Sclerosis Lesions in Brain MRI.

    PubMed

    Subbanna, Nagesh; Precup, Doina; Arnold, Douglas; Arbel, Tal

    2015-01-01

    In this paper, we present IMaGe, a new, iterative two-stage probabilistic graphical model for detection and segmentation of Multiple Sclerosis (MS) lesions. Our model includes two levels of Markov Random Fields (MRFs). At the bottom level, a regular grid voxel-based MRF identifies potential lesion voxels, as well as other tissue classes, using local and neighbourhood intensities and class priors. Contiguous voxels of a particular tissue type are grouped into regions. A higher, non-lattice MRF is then constructed, in which each node corresponds to a region, and edges are defined based on neighbourhood relationships between regions. The goal of this MRF is to evaluate the probability of candidate lesions, based on group intensity, texture and neighbouring regions. The inferred information is then propagated to the voxel-level MRF. This process of iterative inference between the two levels repeats as long as desired. The iterations suppress false positives and refine lesion boundaries. The framework is trained on 660 MRI volumes of MS patients enrolled in clinical trials from 174 different centres, and tested on a separate multi-centre clinical trial data set with 535 MRI volumes. All data consists of T1, T2, PD and FLAIR contrasts. In comparison to other MRF methods, such as, and a traditional MRF, IMaGe is much more sensitive (with slightly better PPV). It outperforms its nearest competitor by around 20% when detecting very small lesions (3-10 voxels). This is a significant result, as such lesions constitute around 40% of the total number of lesions. PMID:26221699

  9. 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.

  10. Focal liver lesions detection and characterization: The advantages of gadoxetic acid-enhanced liver MRI

    PubMed Central

    Palmucci, Stefano

    2014-01-01

    Since its clinical introduction, several studies in literature have investigated gadolinium ethoxybenzhyl diethylenetriaminepentaacetic acid or gadoxetic acid (Gd-EOB-DTPA) properties. Following contrast injection, it provides dynamic vascular phases (arterial, portal and equilibrium phases) and hepatobiliary phase, the latter due to its uptake by functional hepatocytes. The main advantages of Gd-EOB-DTPA of focal liver lesion detection and characterization are discussed in this paper. Namely, we focus on the possibility of distinguishing focal nodular hyperplasia (FNH) from hepatic adenoma (HA), the identification of early hepatocellular carcinoma (HCC) and the pre-operative assessment of metastasis in liver parenchyma. Regarding the differentiation between FNH and HA, adenoma typically appears hypointense in hepatobiliary phase, whereas FNH is isointense or hyperintense to the surrounding hepatic parenchyma. As for the identification of early HCCs, many papers recently published in literature have emphasized the contribution of hepatobiliary phase in the characterization of nodules without a typical hallmark of HCC. Atypical nodules (no hypervascularizaton observed on arterial phase and/or no hypovascular appearance on portal phase) with low signal intensity in the hepatobiliary phase, have a high probability of malignancy. Finally, regarding the evaluation of focal hepatic metastases, magnetic resonance pre-operative assessment using gadoxetic acid allows for more accurate diagnosis. PMID:25067999

  11. 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

  12. Reduced choice-related activity and correlated noise accompany perceptual deficits following unilateral vestibular lesion

    PubMed Central

    Liu, Sheng; Dickman, J. David; Newlands, Shawn D.; DeAngelis, Gregory C.; Angelaki, Dora E.

    2013-01-01

    Signals from the bilateral vestibular labyrinths work in tandem to generate robust estimates of our motion and orientation in the world. The relative contributions of each labyrinth to behavior, as well as how the brain recovers after unilateral peripheral damage, have been characterized for motor reflexes, but never for perceptual functions. Here we measure perceptual deficits in a heading discrimination task following surgical ablation of the neurosensory epithelium in one labyrinth. We found large increases in heading discrimination thresholds and large perceptual biases at 1 wk postlesion. Repeated testing thereafter improved heading perception, but vestibular discrimination thresholds remained elevated 3 mo postlesion. Electrophysiological recordings from the contralateral vestibular and cerebellar nuclei revealed elevated neuronal discrimination thresholds, elevated neurometric-to-psychometric threshold ratios, and reduced trial-by-trial correlations with perceptual decisions [“choice probabilities” (CPs)]. The relationship between CP and neuronal threshold was shallower, but not significantly altered, suggesting that smaller CPs in lesioned animals could be largely attributable to greater neuronal thresholds. Simultaneous recordings from pairs of neurons revealed that correlated noise among neurons was also reduced following the lesion. Simulations of a simple pooling model, which takes into account the observed changes in tuning slope and correlated noise, qualitatively accounts for the elevated psychophysical thresholds and neurometric-to-psychometric ratios, as well as the decreased CPs. Thus, cross-labyrinthine interactions appear to play important roles in enhancing neuronal and perceptual sensitivity, strengthening interneuronal correlations, and facilitating correlations between neural activity and perceptual decisions. PMID:24127575

  13. Detection of atherosclerotic lesions and intimal macrophages using CD36-targeted nanovesicles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. Characteristics of the Small Bowel Lesions Detected by Capsule Endoscopy in Patients with Chronic Kidney Disease

    PubMed Central

    Kawamura, Harunobu; Sakai, Eiji; Endo, Hiroki; Taniguchi, Leo; Hata, Yasuo; Ezuka, Akiko; Nagase, Hajime; Kessoku, Takaomi; Yamada, Eiji; Ohkubo, Hidenori; Higrashi, Takuma; Sekino, Yusuke; Koide, Tomoko; Iida, Hiroshi; Nonaka, Takashi; Takahashi, Hirokazu; Inamori, Masahiko; Maeda, Shin; Nakajima, Atsushi

    2013-01-01

    Obscure gastrointestinal bleeding (OGIB) is one of the common complications in patients with chronic kidney disease (CKD), especially those who are on maintenance hemodialysis (HD). However, little is known about the characteristics of the small-bowel lesions in these patients, or of the factors that could predict the presence of such lesions. Therefore we enrolled a total of 42 CKD patients (including 19 HD patients and 23 non-HD patients), and compared the incidence of the small-bowel lesions among two groups. Furthermore, to identify predictive factors for the presence of small-bowel lesions, we performed multivariate logistic-regression-analyses. The incidence of small-bowel vascular lesions was significantly higher in CKD patients than in age-and-sex matched non-CKD patients (P < 0.001). On the other hand, there was any significant difference of the incidence of small-bowel lesions between HD and non-HD patients. In CKD patients, past history of blood transfusion (OR 5.66; 95% CI 1.10–29.1, P = 0.04) was identified as an independent predictor of the presence of vascular lesions, and history of low-dose aspirin use (OR 6.00; 95% CI 1.13–31.9, P = 0.04) was identified as that of erosive/ulcerated lesions. This indicated that proactive CE examination would be clinically meaningful for these patients. PMID:24065987

  15. Ventromedial hypothalamic lesions change the expression of cell proliferation-related genes and morphology-related genes in rat pancreatic islets

    PubMed Central

    Kiba, Takayoshi; Ishigaki, Yasuhito

    2014-01-01

    Studies in normal rats and ob/ob mice indicated that islet neogenesis does not occur in the intact rodent pancreas. We previously reported that ventromedial hypothalamic (VMH) lesions stimulated cell proliferation of rat pancreatic islet B and acinar cells primarily through a cholinergic receptor mechanism and examined how gene families involved in cell proliferation in total pancreatic tissue are regulated after VMH lesions formation. This study examined how gene families involved in cell proliferation in pancreatic islets alone are regulated after VMH lesions formation. Pancreatic islet RNA was extracted, and differences in gene expression profiles between rats at day 3 after VMH lesioning and sham-VMH-lesioned rats were investigated using DNA microarray and real-time polymerase chain reaction. VMH lesions regulated genes that were involved in functions related to cell cycle and differentiation, growth, binding, apoptosis and morphology in pancreas islets. Real-time polymerase chain reaction also confirmed that gene expression of polo-like kinase 1 (Plk1) and topoisomerase (DNA) II α 170 kDa (Top2a), and stanniocalcin 1 (Stc1) were upregulated at day 3 after the VMH lesions. Ventromedial hypothalamic lesions may change the expression of cell proliferation-related genes and morphology-related genes in rat pancreatic islets. PMID:25658146

  16. Accuracy of faecal occult blood test and Helicobacter pylori stool antigen test for detection of upper gastrointestinal lesions

    PubMed Central

    Lee, Yi-Chia; Chiu, Han-Mo; Chiang, Tsung-Hsien; Yen, Amy Ming-Fang; Chiu, Sherry Yueh-Hsia; Chen, Sam Li-Sheng; Fann, Jean Ching-Yuan; Yeh, Yen-Po; Liao, Chao-Sheng; Hu, Tsung-Hui; Tu, Chia-Hung; Tseng, Ping-Huei; Chen, Chien-Chuan; Chen, Mei-Jyh; Liou, Jyh-Ming; Liao, Wei-Chih; Lai, Yo-Ping; Wang, Chen-Ping; Ko, Jenq-Yuh; Wang, Hsiu-Po; Chiang, Hung; Lin, Jaw-Town; Chen, Hsiu-Hsi; Wu, Ming-Shiang

    2013-01-01

    Objective Highly sensitive guaiac-based faecal occult blood (Hemoccult SENSA) and Helicobacter pylori stool antigen testing might help detect upper gastrointestinal lesions when appended to a colorectal cancer screening programme with faecal immunochemical testing. We evaluated the diagnostic accuracies of two stool tests in detecting upper gastrointestinal lesions. Design Cross-sectional design. Setting Hospital-based and community-based screening settings. Participants A hospital-based deviation cohort of 3172 participants to evaluate test performance and a community-based validation cohort of 3621 to verify the findings. Interventions Three types of stool tests with bidirectional endoscopy as the reference standard. Outcomes Sensitivity, specificity and positive and negative likelihood ratios. Results For detecting upper gastrointestinal lesions in cases with negative immunochemical tests, the sensitivity, specificity, and positive and negative likelihood ratios of the guaiac-based and H pylori antigen tests were 16.3% (95% CI 13.3% to 19.8%), 90.1% (88.9% to 91.2%), 1.64 (1.31 to 2.07), and 0.93 (0.89 to 0.97), respectively, and 52.5% (48.1% to 56.9%), 80.6% (79.0% to 82.1%), 2.71 (2.41 to 3.04) and 0.59 (0.54 to 0.65), respectively. For detecting upper gastrointestinal lesions in cases with normal colonoscopy, the results of the guaiac-based and H pylori antigen tests were 17.9% (14.8% to 21.5%), 90.1% (88.9% to 91.2%), 1.81 (1.45 to 2.26) and 0.91 (0.87 to 0.95), respectively, and 53.1% (48.6% to 57.4%), 80.7% (79.1% to 82.2%), 2.75 (2.45 to 3.08) and 0.58 (0.53 to 0.64), respectively. Within the community, positive predictive values of the immunochemical and H pylori antigen tests were 36.0% (26.0% to 46.0%) and 31.9% (28.3% to 35.5%), respectively, for detecting lower and upper gastrointestinal lesions, which were similar to expected values. Conclusions The H pylori stool antigen test is more accurate than the guaiac-based test in the screening of upper

  17. The impact of basal ganglia lesions on sensorimotor synchronization, spontaneous motor tempo, and the detection of tempo changes.

    PubMed

    Schwartze, Michael; Keller, Peter E; Patel, Aniruddh D; Kotz, Sonja A

    2011-01-20

    The basal ganglia (BG) are part of extensive subcortico-cortical circuits that are involved in a variety of motor and non-motor cognitive functions. Accumulating evidence suggests that one specific function that engages the BG and associated cortico-striato-thalamo-cortical circuitry is temporal processing, i.e., the mechanisms that underlie the encoding, decoding and evaluation of temporal relations or temporal structure. In the current study we investigated the interplay of two processes that require precise representations of temporal structure, namely the perception of an auditory pacing signal and manual motor production by means of finger tapping in a sensorimotor synchronization task. Patients with focal lesions of the BG and healthy control participants were asked to align finger taps to tone sequences that either did or did not contain a tempo acceleration or tempo deceleration at a predefined position, and to continue tapping at the final tempo after the pacing sequence had ceased. Performance in this adaptive synchronization-continuation paradigm differed between the two groups. Selective damage to the BG affected the abilities to detect tempo changes and to perform attention-dependent error correction, particularly in response to tempo decelerations. An additional assessment of preferred spontaneous, i.e., unpaced but regular, production rates yielded more heterogeneous results in the patient group. Together these findings provide evidence for less efficient processing in the perception and the production of temporal structure in patients with focal BG lesions. The results also support the functional role of the BG system in attention-dependent temporal processing. PMID:20883725

  18. A computer simulation study comparing lesion detection accuracy with digital mammography, breast tomosynthesis, and cone-beam CT breast imaging

    SciTech Connect

    Gong Xing; Glick, Stephen J.; Liu, Bob; Vedula, Aruna A.; Thacker, Samta

    2006-04-15

    Although conventional mammography is currently the best modality to detect early breast cancer, it is limited in that the recorded image represents the superposition of a three-dimensional (3D) object onto a 2D plane. Recently, two promising approaches for 3D volumetric breast imaging have been proposed, breast tomosynthesis (BT) and CT breast imaging (CTBI). To investigate possible improvements in lesion detection accuracy with either breast tomosynthesis or CT breast imaging as compared to digital mammography (DM), a computer simulation study was conducted using simulated lesions embedded into a structured 3D breast model. The computer simulation realistically modeled x-ray transport through a breast model, as well as the signal and noise propagation through a CsI based flat-panel imager. Polyenergetic x-ray spectra of Mo/Mo 28 kVp for digital mammography, Mo/Rh 28 kVp for BT, and W/Ce 50 kVp for CTBI were modeled. For the CTBI simulation, the intensity of the x-ray spectra for each projection view was determined so as to provide a total average glandular dose of 4 mGy, which is approximately equivalent to that given in conventional two-view screening mammography. The same total dose was modeled for both the DM and BT simulations. Irregular lesions were simulated by using a stochastic growth algorithm providing lesions with an effective diameter of 5 mm. Breast tissue was simulated by generating an ensemble of backgrounds with a power law spectrum, with the composition of 50% fibroglandular and 50% adipose tissue. To evaluate lesion detection accuracy, a receiver operating characteristic (ROC) study was performed with five observers reading an ensemble of images for each case. The average area under the ROC curves (A{sub z}) was 0.76 for DM, 0.93 for BT, and 0.94 for CTBI. Results indicated that for the same dose, a 5 mm lesion embedded in a structured breast phantom was detected by the two volumetric breast imaging systems, BT and CTBI, with statistically

  19. Perirhinal cortex lesions in rats: Novelty detection and sensitivity to interference.

    PubMed

    Albasser, Mathieu M; Olarte-Sánchez, Cristian M; Amin, Eman; Brown, Malcolm W; Kinnavane, Lisa; Aggleton, John P

    2015-06-01

    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

  20. 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.

  1. Improved detectability of small-bowel lesions via capsule endoscopy with computed virtual chromoendoscopy: A pilot study

    PubMed Central

    Imagawa, Hiroki; Oka, Shiro; Tanaka, Shinji; Noda, Ikue; Higashiyama, Makoto; Sanomura, Youji; Shishido, Takayoshi; Yoshida, Shigeto; Chayama, Kazuaki

    2011-01-01

    Objective. Real-time video capsule endoscopy (CE) with flexible spectral imaging color enhancement (FICE) improves visibility of small-bowel lesions. This article aims to clarify whether CE-FICE also improves detectability of small-bowel lesions. Patients and methods. A total of 55 patients who underwent CE at Hiroshima University Hospital during the period November 2009 through March 2010 were enrolled in the study. Five patients were excluded from the study because residues and transit delays prevented sufficient evaluation. Thus, 50 patients participated. Two experienced endoscopists (each having interpreted more than 50 capsule videos) analyzed the images. One interpreted conventional capsule videos; the other, blinded to interpretation of the conventional images, interpreted CE-FICE images obtained at settings 1-3 (setting 1: red 595 nm, green 540 nm, blue 535 nm; setting 2: red 420 nm, green 520 nm, blue 530 nm; setting 3: red 595 nm, green 570 nm, blue 415 nm). Lesions were classified as angioectasia, erosion, ulceration, or tumor. Detectability was compared between the two modalities. Time taken to interpret the capsule videos was also determined. Results. Seventeen angioectasias were identified by conventional CE; 48 were detected by CE-FICE at setting 1, 45 at setting 2, and 24 at setting 3, with significant differences at settings 1 and 2 (p = 0.0003, p < 0.0001, respectively). Detection of erosion, ulceration, and tumor did not differ statistically between conventional CE and CE-FICE, nor did interpretation time (conventional CE 36 ± 6.9 min; CE-FICE setting 1, 36 ± 6.4 min; setting 2, 38 ± 5.8 min; setting 3, 35 ± 6.7 min). Conclusions. CE-FICE is superior in the lesion detection in comparison with conventional CE and improves detection of angioectasia. PMID:21619482

  2. Immunoglobulin G4-related multiple cardiovascular lesions successfully treated with a combination of open surgery and corticosteroid therapy.

    PubMed

    Kan-o, Meikun; Kado, Yuichiro; Sadanaga, Atsushi; Tamiya, Sadafumi; Toyoshima, Satoshi; Sakamoto, Masato

    2015-06-01

    Immunoglobulin G4-related disease, a newly emerging systemic autoimmune disorder, can potentially involve the cardiovascular system. The standard treatment for immunoglobulin G4-related cardiovascular disease has not been established. We encountered a very rare case of an immunoglobulin G4-related inflammatory abdominal aortic aneurysm coexisting with a coronary artery aneurysm and periarteritis. The patient underwent surgical resection for the abdominal aortic aneurysm, followed by successful corticosteroid therapy for the coronary artery lesions. This is the first report of steroid-sensitive immunoglobulin G4-related coronary artery disease. A carefully planned treatment strategy for the multiple cardiovascular lesions was invaluable in the present case. PMID:24360234

  3. 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. PMID:26203886

  4. 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.

  5. 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.

  6. Frontotemporal lobar degeneration FTLD-tau: preclinical lesions, vascular, and Alzheimer-related co-pathologies.

    PubMed

    Thal, Dietmar Rudolf; von Arnim, Christine A F; Griffin, W Sue T; Mrak, Robert E; Walker, Lauren; Attems, Johannes; Arzberger, Thomas

    2015-07-01

    Frontotemporal lobar degeneration with τ pathology (FTLD-tau) is one of a group of neurodegenerative diseases that manifests with cognitive decline. Alzheimer (AD) and cerebrovascular lesions are commonly noted in the brains of most elderly individuals, begging the question as to whether (a) coexisting AD and vascular pathology or age contribute to the development of FTLD-tau disorders and vice versa and (b) FTLD-tau-like pathology can be found in non-diseased individuals. We studied brains of FTLD-tau cases exhibiting (a) argyrophilc grain disease (AGD), (b) progressive supranuclear palsy (PSP), (c) corticobasal degeneration (CBD), or (d) Pick's disease (PiD) for coexisting AD and vascular pathology for comparison with that of non-diseased individuals and AD patients. We confirmed that AGD lowered the threshold for AD pathology to cause dementia. Such an effect was not seen in PSP, CBD, or PiD. In PiD, white matter degeneration and demyelination was observed in the frontal and temporal lobes in association with small vessel disease (SVD)-related changes in white matter arteries. Age at death varied among the four types of FTLD-tau. PiD cases were youngest at death followed by CBD, PSP, and finally AGD. In 9.8% of non-diseased controls, we found grains, coiled bodies, and/or τ-positive astrocytes mimicking an AGD-like pattern. Moreover, the prevalence of FTLD-tau pathology in non-diseased individuals increased with age. In summary, this study demonstrates that age impacts of the diversity of neuropathological changes in FTLD-tau. The age-related coexistence of AD-related pathology is, thereby, associated with AGD but not with PSP, CBD, and PiD. Moreover, severe SVD and white matter demyelination is associated with PiD indicating a role of vascular copathology in this type of FTLD-tau. Finally, our finding that FTLD-tau-related pathological lesions occur in non-diseased individuals suggests that preclinical stages of FTLD-tau exist. As such, our results indicate

  7. 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. PMID:24836644

  8. Thresholding lesion overlap difference maps: application to category-related naming and recognition deficits.

    PubMed

    Rudrauf, David; Mehta, Sonya; Bruss, Joel; Tranel, Daniel; Damasio, Hanna; Grabowski, Thomas J

    2008-07-01

    Lesion overlap difference maps have been used in studies designed to test anatomical hypotheses regarding brain systems critical for various cognitive and behavioral tasks, including naming and recognition of concrete entities [Damasio, H., Tranel, D., Grabowski, T., Adolphs, R., Damasio, A., 2004. Neural systems behind word and concept retrieval. Cognition 92, 179-229]. To date, the interpretation of these results has focused on areas of maximum lesion overlap differences. Here we explore formal methods for statistical thresholding and power analysis. We derive exact voxel-wise statistics describing the behavior of lesion overlap difference maps and lesion proportion difference maps under the null hypothesis of no association between lesion and deficit, and we apply the statistics to a large subset of the subjects previously reported in [Damasio, H., Tranel, D., Grabowski, T., Adolphs, R., Damasio, A., 2004. Neural systems behind word and concept retrieval. Cognition 92, 179-229], in order to reassess the lesion correlates of deficits in naming and recognition for five categories of concrete entities. The thresholded maps confirmed many of the results reported previously, but also revealed some differences. Differences in spatial distribution of the lesion correlates of impaired naming of unique versus nonunique entities were confirmed in the inferotemporal region (IT), although overlapping components across categories became apparent in left IT. Additionally, the left inferior frontal gyrus (IFG) was implicated in naming both categories of nonunique natural entities (animals and fruits/vegetables). In corresponding power analyses, we estimated where significant effects could be found under an assumption of maximal effect size given the observed spatial distribution of lesions. Such "effective coverage maps" are valuable for the interpretation of the results, notably because of heterogeneity in lesion coverage encountered in lesion studies. We strongly suggest

  9. Cognitive impairment in paediatric multiple sclerosis patients is not related to cortical lesions.

    PubMed

    Rocca, Maria A; De Meo, Ermelinda; Amato, Maria P; Copetti, Massimiliano; Moiola, Lucia; Ghezzi, Angelo; Veggiotti, Pierangelo; Capra, Ruggero; Fiorino, Agnese; Pippolo, Lorena; Pera, Maria C; Falini, Andrea; Comi, Giancarlo; Filippi, Massimo

    2015-06-01

    We investigated the contribution of cortical lesions to cognitive impairment in 41 paediatric MS patients. Thirteen (32%) paediatric MS patients were considered as cognitively impaired. T2-hyperintense and T1-hypointense white matter lesion volumes did not differ between cognitively impaired and cognitively preserved MS patients. Cortical lesions number, cortical lesions volume and grey matter volume did not differ between cognitively impaired and cognitively preserved patients, whereas white matter volume was significantly lower in cognitively impaired versus cognitively preserved MS patients (p=0.01). Contrary to adult MS, cortical lesions do not seem to contribute to cognitive impairment in paediatric MS patients, which is likely driven by white matter damage. PMID:25392332

  10. Proximal caries lesion detection in primary teeth: does this justify the association of diagnostic methods?

    PubMed

    Bussaneli, D G; Restrepo, M; Boldieri, T; Albertoni, T H; Santos-Pinto, L; Cordeiro, R C L

    2015-12-01

    The aim of this clinical study was to evaluate and compare the performance of visual exam with use of the Nyvad criteria (visual examination - (VE)), interproximal radiography (BW), laser fluorescence device (DIAGNOdent Pen-DDPen), and their association in the diagnosis of proximal lesions in primary teeth. For this purpose, 45 children (n = 59 surfaces) of both sexes, aged between 5 and 9 years were selected, who presented healthy primary molars or primary molars with signs suggestive of the presence of caries lesions. The surfaces were clinically evaluated and coded according to the Nyvad criteria and immediately afterwards with the DDPen. Radiographic exam was performed only on the surfaces coded with Nyvad scores 2, 3, 5, or 6. Active caries lesions and/or those with discontinuous surfaces were restored, considering the depth of lesion as reference standard. Sensitivity, specificity, accuracy, and area under ROC curve were calculated for each technique and its associations. Visual exam with Nyvad criteria presented the highest specificity, accuracy, and area under ROC curve values. The DDPen presented the highest sensitivity values. Association with one or more methods resulted in an increase in specificity. The performance of visual, radiographic, and DDpen exams and their associations were good; however, the clinical examination with the Nyvad criteria was sufficient for the diagnosis of interproximal lesions in primary teeth. PMID:26286856

  11. 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.

  12. Alterations of muscarinic receptor subtypes in pathways relating to memory: Effects of lesions and transplants

    SciTech Connect

    Dawson, V.L.

    1989-01-01

    Muscarinic cholinergic receptors have been classified pharmacologically into two distinct populations designated muscarinic type-one (M-1) and mscarinic type-two (M-2). The semiquantitative technique of receptor autoradiography was used to examine the anatomical and cellular distribution, and densities of M-1 and M-2 receptors in the rate brain. Muscarinic receptors were labeled with the classical antagonist ({sup 3}H)quinuclidinyl benzilate (QNB). Differentiation of the muscarinic subtypes was accomplished by competition studies of ({sup 3}H)QNB against the relatively selective M-1 antagonist pirenzepine (PZ), and the relatively selective M-2 antagonist, AFDX-116. In addition, M-1 and M-2 receptors were directly labeled with ({sup 3}H)PZ and ({sup 3}H)AFDX-116, respectively. Cholinergic pathways from the large cholinergic neurons in the nucleus basalis magnocellularis (NBM) to the cortex and from the medial septum (MS) to the hippocampus were examined by lesioning with the selective cholinergic neurotoxin, AF64A. Bilateral cerebral cortical infarction was performed in order to analyze potential changes in muscarinic receptor populations in subcortical structures that are sensitive to cortical infarction. Finally, the response of muscarinic receptors to fetal septodiagonal band transplants in the deafferentated hippocampus was examined.

  13. A comparison of lesion detection accuracy using digital mammography and flat-panel CT breast imaging (Honorable Mention Poster Award)

    NASA Astrophysics Data System (ADS)

    Gong, Xing; Vedula, Aruna A.; Thacker, Samta; Glick, Stephen J.

    2005-04-01

    Although conventional mammography is currently the best modality to detect early breast cancer, it is limited in that the recorded image represents the superposition of a 3D object onto a 2D plane. As an alternative, cone-beam CT breast imaging with a CsI based flat-panel imager (CTBI) has been proposed with the ability to provide 3D visualization of breast tissue. To investigate possible improvements in lesion detection accuracy using CTBI over digital mammography (DM), a computer simulation study was conducted using simulated lesions embedded into a structured 3D breast model. The computer simulation realistically modeled x-ray transport through a breast model, as well as the signal and noise propagation through the flat-panel imager. Polyenergetic x-ray spectra of W/Al 50 kVp for CTBI and Mo/Mo 28 kVp for DM were modeled. For the CTBI simulation, the intensity of the x-ray spectra for each projection view was determined so as to provide a total mean glandular dose (MGD) of 4 mGy, which is approximately equivalent to that given in a conventional two-view screening mammography study. Since only one DM view was investigated here, the intensity of the DM x-ray spectra was defined to give 2 mGy MGD. Irregular lesions were simulated by using a stochastic growth algorithm providing lesions with an effective diameter of 5 mm. Breast tissue was simulated by generating an ensemble of backgrounds with a power law spectrum. To evaluate lesion detection accuracy, a receiver operating characteristic (ROC) study was performed with 4 observers reading an ensemble of images for each case. The average area under the ROC curves (Az) was 0.94 for CTBI, and 0.81 for DM. Results indicate that a 5 mm lesion embedded in a structured breast phantom can be detected by CT breast imaging with statistically significant higher confidence than with digital mammography.

  14. Frequency and nature of spontaneous age-related eye lesions observed in a 2-year inhalation toxicity study in rats.

    PubMed

    Wegener, A; Kaegler, M; Stinn, W

    2002-01-01

    A group of 160 Wistar rats (both sexes) from a larger chronic inhalation toxicity study was monitored at baseline and after 1 and 2 years with a photo-slitlamp microscope and a direct ophthalmoscope to record spontaneous age-related eye lesions and treatment-related eye lesions over a period of 24 months. A second group from the same study was monitored at the start and after 5 months of a 6-month posttreatment period immediately following the inhalation period. Rats were nose-only exposed for 6 h/day, 7 days/week, for 2 years to low (3 microg/l) or high (10 microg/l) total particulate matter concentrations of room-aged cigarette sidestream smoke (RASS) or diesel engine exhaust (DEE). Control animals were exposed to filtered fresh air. All ophthalmological examinations were performed in mydriasis, and relevant observations were documented on color slide film. At baseline, all animals with eye lesions were excluded from the study. After 1 year, only minor lesions were found: retrolental opacities (14%) and a few cases of corneal dryness with reddish lid margins. After 2 years, 23% of the animals had unilateral or bilateral retrolental opacities, but the most frequent eye lesions were posterior subcapsular cataracts (PSC, 32%). Water clefts and spokes were found in 11% of the lenses and mature cataracts in 6%. All other eye lesions observed were much less frequent. There were a few cases of glaucoma, corneal dryness and stromal neovascularization. The frequency and type of lesion in animals monitored from the start of the posttreatment period was comparable to what was seen after 2 years. Toward the end of this period the frequency of mature cataracts went up to 9% and that of (secondary) glaucomas to 5%. None of the eye lesions observed showed any association in frequency or severity of expression to the treatment, either RASS or DEE, or to the sex of the animals. In comparison to the (limited) literature data available, far fewer corneal lesions were found in this

  15. Comparison of two fat-suppressed magnetic resonance imaging pulse sequences to standard t2-weighted images for brain parenchymal contrast and lesion detection in dogs with inflammatory intracranial disease.

    PubMed

    Young, Benjamin D; Mankin, Joseph M; Griffin, John F; Fosgate, Geoffrey T; Fowler, Jennifer L; Levine, Jonathan M

    2015-01-01

    T2-weighted (T2w) sequences are commonly relied upon in magnetic resonance imaging protocols for the detection of brain lesions in dogs. Previously, the effect of fluid suppression via fluid-attenuated inversion recovery (FLAIR) has been compared to T2-weighting with mixed results. Short tau inversion recovery (STIR) has been reported to increase the detection of some CNS lesions in people. The purpose of the current study was to evaluate the effect of fat suppression on brain parenchymal contrast resolution and lesion detection in dogs. We compared three sequences: T2w images, STIR, and T2w FLAIR with chemical fat suppression (T2-FLAIR-FS) in dogs with meningoencephalitis. Dogs with meningoencephalitis and dogs with idiopathic epilepsy were retrospectively identified and anonymized. Evaluators recorded the presence or absence of lesions within 12 predetermined brain regions on randomized sequences, viewing and scoring each sequence individually. Additionally, signal-to-noise ratios, contrast-to-noise ratios, and relative contrast (RC) were measured in a reference population. Short tau inversion recovery sequences had the highest RC between gray and white matter. While descriptively more lesions were identified by evaluators on T2-FLAIR-FS images, there was no statistical difference in the relative sensitivity of lesion detection between the sequences. Nor was there a statistical difference in false lesion detection within our reference population. Short tau inversion recovery may be favored for enhanced anatomic contrast depiction in brain imaging. No benefit of the inclusion of a fat-suppressed T2-FLAIR sequence was found. PMID:25395066

  16. Phase-based metamorphosis of diffusion lesion in relation to perfusion values in acute ischemic stroke.

    PubMed

    Rekik, Islem; Allassonnière, Stéphanie; Luby, Marie; Carpenter, Trevor K; Wardlaw, Joanna M

    2015-01-01

    Examining the dynamics of stroke ischemia is limited by the standard use of 2D-volume or voxel-based analysis techniques. Recently developed spatiotemporal models such as the 4D metamorphosis model showed promise for capturing ischemia dynamics. We used a 4D metamorphosis model to evaluate acute ischemic stroke lesion morphology from the acute diffusion-weighted imaging (DWI) to final T2-weighted imaging (T2-w). In 20 representative patients, we metamorphosed the acute lesion to subacute lesion to final infarct. From the DWI lesion deformation maps we identified dynamic lesion areas and examined their association with perfusion values inside and around the lesion edges, blinded to reperfusion status. We then tested the model in ten independent patients from the STroke Imaging Repository (STIR). Perfusion values varied widely between and within patients, and were similar in contracting and expanding DWI areas in many patients in both datasets. In 25% of patients, the perfusion values were higher in DWI-contracting than DWI-expanding areas. A similar wide range of perfusion values and ongoing expansion and contraction of the DWI lesion were seen subacutely. There was more DWI contraction and less expansion in patients who received thrombolysis, although with widely ranging perfusion values that did not differ. 4D metamorphosis modeling shows promise as a method to improve use of multimodal imaging to understand the evolution of acute ischemic tissue towards its fate. PMID:26288755

  17. 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

  18. Effect of 18F-FDG uptake time on lesion detectability in PET imaging of early stage breast cancer

    PubMed Central

    Wangerin, Kristen A.; Muzi, Mark; Peterson, Lanell M.; Linden, Hannah M.; Novakova, Alena; O'Sullivan, Finbarr; Kurland, Brenda F.; Mankoff, David A.; Kinahan, Paul E.

    2016-01-01

    Prior reports have suggested that delayed FDG-PET oncology imaging can improve the contrast-to-noise ratio (CNR) for known lesions. Our goal was to estimate realistic bounds for lesion detectability for static measurements with one to four hours between FDG injection and image acquisition. Tumor and normal tissue kinetic model parameters were estimated from dynamic PET studies of patients with early stage breast cancer. These were used to generate time-activity curves (TACs) out to four hours, for which we assumed both nonreversible and reversible models with different rates of FDG dephosphorylation (k4). For each pair of tumor and normal tissue TACs, 600 PET sinogram realizations were generated, and images were reconstructed using OSEM. Test statistics for each tumor and normal tissue region of interest were output from the computer model observers and evaluated using an ROC analysis with the calculated AUC providing a measure of lesion detectability. For the nonreversible model (k4 = 0), the AUC increased in 11/23 (48%) of patients for one to two hours after the current standard post-radiotracer injection imaging window of one hour. This improvement was driven by increased tumor/normal tissue contrast before the impact of increased noise due to radiotracer decay began to dominate the imaging signal. As k4 was increased from 0 to 0.01 min−1, the time of maximum detectability shifted earlier, as the decreasing FDG concentration in the tumor lowered the CNR. These results imply that delayed PET imaging may reveal low-conspicuity lesions that would have otherwise gone undetected. PMID:26807443

  19. Treponemes Detected in Digital Dermatitis Lesions in Brazilian Dairy Cattle and Possible Host Reservoirs of Infection

    PubMed Central

    Nascimento, Ligia Valéria; Mauerwerk, Marlise Teresinha; dos Santos, Cibelli Lopes; de Barros Filho, Ivan Roque; Birgel Júnior, Eduardo Harry; Madeira, Humberto Maciel França

    2015-01-01

    The main pathogenic treponemes causing bovine digital dermatitis were identified from 17 infected herds in southern Brazil for the first time in this study using PCR. We did not find a relationship between treponeme phylogroup composition and clinical classification. Treponema phagedenis was present in all lesions. Rumen fluid was implicated as a reservoir location for these pathogens. PMID:25788552

  20. Use of electrical impedance spectroscopy to detect malignant and potentially malignant oral lesions

    PubMed Central

    Murdoch, Craig; Brown, Brian H; Hearnden, Vanessa; Speight, Paul M; D’Apice, Katy; Hegarty, Anne M; Tidy, John A; Healey, T Jamie; Highfield, Peter E; Thornhill, Martin H

    2014-01-01

    The electrical properties of tissues depend on their architecture and cellular composition. We have previously shown that changes in electrical impedance can be used to differentiate between different degrees of cervical dysplasia and cancer of the cervix. In this proof-of-concept study, we aimed to determine whether electrical impedance spectroscopy (EIS) could distinguish between normal oral mucosa; benign, potentially malignant lesions (PML); and oral cancer. EIS data were collected from oral cancer (n=10), PML (n=27), and benign (n=10) lesions. EIS from lesions was compared with the EIS reading from the normal mucosa on the contralateral side of the mouth or with reference spectra from mucosal sites of control subjects (n=51). Healthy controls displayed significant differences in the EIS obtained from different oral sites. In addition, there were significant differences in the EIS of cancer and high-risk PML versus low-risk PML and controls. There was no significant difference between benign lesions and normal controls. Study subjects also deemed the EIS procedure considerably less painful and more convenient than the scalpel biopsy procedure. EIS shows promise at distinguishing among malignant, PML, and normal oral mucosa and has the potential to be developed into a clinical diagnostic tool. PMID:25285005

  1. Impact of lesion segmentation metrics on computer-aided diagnosis/detection in breast computed tomography

    PubMed Central

    Kuo, Hsien-Chi; Giger, Maryellen L.; Reiser, Ingrid; Drukker, Karen; Boone, John M.; Lindfors, Karen K.; Yang, Kai; Edwards, Alexandra

    2014-01-01

    Abstract. Evaluation of segmentation algorithms usually involves comparisons of segmentations to gold-standard delineations without regard to the ultimate medical decision-making task. We compare two segmentation evaluations methods—a Dice similarity coefficient (DSC) evaluation and a diagnostic classification task–based evaluation method using lesions from breast computed tomography. In our investigation, we use results from two previously developed lesion-segmentation algorithms [a global active contour model (GAC) and a global with local aspects active contour model]. Although similar DSC values were obtained (0.80 versus 0.77), we show that the global + local active contour (GLAC) model, as compared with the GAC model, is able to yield significantly improved classification performance in terms of area under the receivers operating characteristic (ROC) curve in the task of distinguishing malignant from benign lesions. [Area under the ROC curve (AUC)=0.78 compared to 0.63, p≪0.001]. This is mainly because the GLAC model yields better detailed information required in the calculation of morphological features. Based on our findings, we conclude that the DSC metric alone is not sufficient for evaluating segmentation lesions in computer-aided diagnosis tasks. PMID:26158052

  2. Psychosis-related matricide associated with a lesion of the ventromedial prefrontal cortex.

    PubMed

    Orellana, Gricel; Alvarado, Luis; Muñoz-Neira, Carlos; Ávila, Rodrigo; Méndez, Mario F; Slachevsky, Andrea

    2013-01-01

    Matricide, the killing of a mother by her biological child, is a rare event. We report a case of matricide associated with a woman who sustained a right ventromedial prefrontal lesion during surgery for nasal polyposis that was performed when she was 40 years old. After her surgery, she developed psychotic symptoms associated with the emergence of antisocial behavior. She committed matricide 22 years later. Neuropsychological evaluation showed decreased frontal-executive deficits, and magnetic resonance imaging revealed a lesion in the right gyrus rectus area of the ventromedial prefrontal region. This case suggests that a secondary psychotic syndrome associated with a lesion in the frontal neural network, which is disturbed in psychopathy, could facilitate homicidal behavior. Furthermore, this case has legal implications for the prosecution of murder associated with a brain lesion. PMID:24051593

  3. Genetics of age-related white matter lesions from linkage to genome wide association studies

    PubMed Central

    Freudenberger, Paul; Schmidt, Reinhold; Schmidt, Helena

    2012-01-01

    White matter lesions are a frequent phenomenon in the elderly and contribute to the development of disability. The mechanisms underlying these brain lesions are still not fully understood with age and hypertension being the most well established risk factors. The heritability of white matter lesions is consistently high in different populations. Candidate gene studies strongly support the role of genes involved in the renin–angiotensin system, as well as Notch3 signaling. The recent genome wide association study by the CHARGE consortium identified a novel locus on chromosome 17q25 harboring several genes such as TRIM65 and TRIM47 which pinpoint to possible novel mechanisms leading to white matter lesions. PMID:22795385

  4. Label-free surface-enhanced Raman spectroscopy for detection of colorectal cancer and precursor lesions using blood plasma

    PubMed Central

    Feng, Shangyuan; Wang, Wenbo; Tai, Isabella T.; Chen, Guannan; Chen, Rong; Zeng, Haishan

    2015-01-01

    Fecal based tests have limited diagnostic values in detecting adenomatous polyps, the precursor lesions to colorectal cancer (CRC). Surface enhanced Raman spectroscopy (SERS) using silver nanoparticles as substrate is a multiplexed analytical technique capable of detecting biomolecules with high sensitivity. This study utilizes SERS to analyze blood plasma for detecting both CRC and adenomatous polyps for the first time. Blood plasma samples are collected from healthy control subjects and patients diagnosed with adenomas and CRC. Using a real-time Raman system, SERS spectra for blood plasma samples are measured in 1 s. The collected SERS spectra are analyzed with partial least squares-discriminant analysis. Classification of normal versus CRC plus adenomatous polyps achieved diagnostic sensitivity of 86.4% and specificity of 80%. The results suggest that blood plasma SERS analysis could be a potential screening test to detect both CRC and adenomas. PMID:26417518

  5. Ability of laser fluorescence device associated with fluorescent dyes in detecting and quantifying early smooth surface caries lesions.

    PubMed

    Mendes, Fausto Medeiros; de Oliveira, Elisabeth; de Faria, Dalva Lúcia Araújo; Nicolau, José

    2006-01-01

    A laser fluorescence (LF) device is a portable tool, but it does not measure minor mineral changes. Our in vitro study aim is to propose the association of an LF with two fluorescent dyes and to evaluate the performance in detecting and quantifying early demineralization. Artificial caries lesions are created in 40 primary canine teeth using a demineralizing solution (pH=4.8) for 12, 24, 48, and 96 h. LF measurements are performed with DIAGNOdent after demineralization in these samples and in 20 sound primary teeth. Measurements with LF with 0.2-mM tetrakis(N-methylpyridyl)porphyrin (LF TMPyP) and with 4-mM protoporphyrin IX (LF PPIX) are made. The amount of calcium loss is determined by atomic emission spectrometry. A correlation between LF and LF with dyes and mineral loss and receiver operating characteristics analysis are performed, as well as comparisons of sensitivity, specificity, and accuracy values. Significant correlation is obtained with LF TMPyP and mineral loss of lesions demineralized for 24, 48, and 96 h. Better performance is achieved with LF TMPyP for all parameters than with LF alone. LF PPIX does not present good results. In conclusion, LF TMPyP provides good performance in detecting and quantifying very early enamel caries lesions. PMID:16674197

  6. In vivo detection and replication studies of α-anomeric lesions of 2'-deoxyribonucleosides.

    PubMed

    Amato, Nicholas J; Zhai, Qianqian; Navarro, Diana C; Niedernhofer, Laura J; Wang, Yinsheng

    2015-09-30

    DNA damage, arising from endogenous metabolism or exposure to environmental agents, may perturb the transmission of genetic information by blocking DNA replication and/or inducing mutations, which contribute to the development of cancer and likely other human diseases. Hydroxyl radical attack on the C1', C3' and C4' of 2-deoxyribose can give rise to epimeric 2-deoxyribose lesions, for which the in vivo occurrence and biological consequences remain largely unexplored. Through independent chemical syntheses of all three epimeric lesions of 2'-deoxyguanosine (dG) and liquid chromatography-tandem mass spectrometry analysis, we demonstrated unambiguously the presence of substantial levels of the α-anomer of dG (α-dG) in calf thymus DNA and in DNA isolated from mouse pancreatic tissues. We further assessed quantitatively the impact of all four α-dN lesions on DNA replication in Escherichia coli by employing a shuttle-vector method. We found that, without SOS induction, all α-dN lesions except α-dA strongly blocked DNA replication and, while replication across α-dA was error-free, replicative bypass of α-dC and α-dG yielded mainly C→A and G→A mutations. In addition, SOS induction could lead to markedly elevated bypass efficiencies for the four α-dN lesions, abolished the G→A mutation for α-dG, pronouncedly reduced the C→A mutation for α-dC and triggered T→A mutation for α-dT. The preferential misincorporation of dTMP opposite the α-dNs could be attributed to the unique base-pairing properties of the nucleobases elicited by the inversion of the configuration of the N-glycosidic linkage. Our results also revealed that Pol V played a major role in bypassing α-dC, α-dG and α-dT in vivo. The abundance of α-dG in mammalian tissue and the impact of the α-dNs on DNA replication demonstrate for the first time the biological significance of this family of DNA lesions. PMID:26202973

  7. In vivo detection and replication studies of α-anomeric lesions of 2′-deoxyribonucleosides

    PubMed Central

    Amato, Nicholas J.; Zhai, Qianqian; Navarro, Diana C.; Niedernhofer, Laura J.; Wang, Yinsheng

    2015-01-01

    DNA damage, arising from endogenous metabolism or exposure to environmental agents, may perturb the transmission of genetic information by blocking DNA replication and/or inducing mutations, which contribute to the development of cancer and likely other human diseases. Hydroxyl radical attack on the C1′, C3′ and C4′ of 2-deoxyribose can give rise to epimeric 2-deoxyribose lesions, for which the in vivo occurrence and biological consequences remain largely unexplored. Through independent chemical syntheses of all three epimeric lesions of 2′-deoxyguanosine (dG) and liquid chromatography-tandem mass spectrometry analysis, we demonstrated unambiguously the presence of substantial levels of the α-anomer of dG (α-dG) in calf thymus DNA and in DNA isolated from mouse pancreatic tissues. We further assessed quantitatively the impact of all four α-dN lesions on DNA replication in Escherichia coli by employing a shuttle-vector method. We found that, without SOS induction, all α-dN lesions except α-dA strongly blocked DNA replication and, while replication across α-dA was error-free, replicative bypass of α-dC and α-dG yielded mainly C→A and G→A mutations. In addition, SOS induction could lead to markedly elevated bypass efficiencies for the four α-dN lesions, abolished the G→A mutation for α-dG, pronouncedly reduced the C→A mutation for α-dC and triggered T→A mutation for α-dT. The preferential misincorporation of dTMP opposite the α-dNs could be attributed to the unique base-pairing properties of the nucleobases elicited by the inversion of the configuration of the N-glycosidic linkage. Our results also revealed that Pol V played a major role in bypassing α-dC, α-dG and α-dT in vivo. The abundance of α-dG in mammalian tissue and the impact of the α-dNs on DNA replication demonstrate for the first time the biological significance of this family of DNA lesions. PMID:26202973

  8. EFFICACY OF THE ENNEKING STAGING SYSTEM IN RELATION TO TREATING BENIGN BONE TUMORS AND TUMOR-LIKE BONE LESIONS

    PubMed Central

    Nogueira Drumond, José Marcos

    2015-01-01

    Objective: To evaluate the efficacy of the Enneking staging system for determining the prognosis, planning surgical treatment and indicating adjuvant therapy for benign bone tumors (BBT) and tumor-like bone lesions (TBL). Methods: A retrospective multicenter, descriptive, nonrandomized study was carried out on a representative sample comprising a large series of 165 patients with a total of 168 benign bone tumors and tumor-like bone lesions. The patient sample was typical, and matched the literature in all respects. All the patients were classified according to the Enneking staging system, and the initial staging of each lesion was correlated with its behavior after either conservative or surgical treatment, in order to determine the efficacy of the system. The treatment options and complications were described and analyzed. Results: The results from the treatment provided 95.2% agreement with the Enneking staging system, with a 95% confidence interval of between 90.8 and 97.9%. Of the 168 tumors treated, only eight (4.8%) could not be controlled in relation to the initial treatment indicated by the Enneking staging system. Tumors classified as active were the most prevalent, comprising 73.2% of the lesions. Tumor recurrence was significantly more frequent (p < 0.001) in the aggressive stage. All the patients staged as latent evolved to cure. The study suggested that surgery with wide margins, for aggressive lesions, could provide better lesion control, with a lower recurrence rate (p > 0.001). For latent and active lesions, the study demonstrated the efficacy of both expectant treatment and excision, with or without autogenous bone graft. Conclusion: The results confirm that the Enneking staging system was very efficient in determining the prognosis, enabling surgical planning and indicating adjuvant therapy for treatment of BBT and TBL. PMID:27019838

  9. Effect of smoking on attack rates of pulmonary and pleural lesions related to exposure to asbestos dust.

    PubMed Central

    McMillan, G H; Pethybridge, R J; Sheers, G

    1980-01-01

    In follow-up studies of samples of employees at two of Her Majesty's Dockyards the prevalence of asbestos-related lesions in smokers and ex-smokers was statistically significantly higher than in non-smokers even when differences in age and exposure risk were considered. PMID:7426478

  10. GPCALMA: implementation in Italian hospitals of a computer aided detection system for breast lesions by mammography examination.

    PubMed

    Lauria, Adele

    2009-06-01

    We describe the implementation in several Italian hospitals of a computer aided detection (CAD) system, named GPCALMA (grid platform for a computer aided library in mammography), for the automatic search of lesions in X-ray mammographies. GPCALMA has been under development since 1999 by a community of physicists of the Italian National Institute for Nuclear Physics (INFN) in collaboration with radiologists. This CAD system was tested as a support to radiologists in reading mammographies. The main system components are: (i) the algorithms implemented for the analysis of digitized mammograms to recognize suspicious lesions, (ii) the database of digitized mammographic images, and (iii) the PC-based digitization and analysis workstation and its user interface. The distributed nature of data and resources and the prevalence of geographically remote users suggested the development of the system as a grid application: the design of this networked version is also reported. The paper describes the system architecture, the database of digitized mammographies, the clinical workstation and the medical applications carried out to characterize the system. A commercial CAD was evaluated in a comparison with GPCALMA by analysing the medical reports obtained with and without the two different CADs on the same dataset of images: with both CAD a statistically significant increase in sensitivity was obtained. The sensitivity in the detection of lesions obtained for microcalcification and masses was 96% and 80%, respectively. An analysis in terms of receiver operating characteristic (ROC) curve was performed for massive lesion searches, achieving an area under the ROC curve of A(z)=0.783+/-0.008. Results show that the GPCALMA CAD is ready to be used in the radiological practice, both for screening mammography and clinical studies. GPCALMA is a starting point for the development of other medical imaging applications such as the CAD for the search of pulmonary nodules, currently under