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Sample records for lesion detection rate

  1. PET-CT detection rate of primary breast cancer lesions. Correlation with the clinicopathological factors

    International Nuclear Information System (INIS)

    Ogawa, Tomoko; Tozaki, Mitsuhiro; Fukuma, Eisuke

    2008-01-01

    One hundred and forty lesions of primary breast cancer underwent positron emission tomography (PET)-CT between June 2006 and May 2007. The PET-CT detection rate of primary breast cancer lesions was 72.1%. The detection rate was 52.1% for invasive cancer ≤20 mm, 92.8% for invasive breast cancers >20 mm, and these results were significant. In the present study, no significant relationship was observed between tumor types, however, invasive lobular carcinoma showed a lower detection rate, 58.3%. The PET-CT results were not significantly affected by either estrogen and progesterone receptors or distant metastasis. A significant correlation regarding the detection rate of PET-CT was found with HER2 status, tumor grade, and axillary lymph node status. The detection rate was 100% for invasive cancer ≤20 mm when the interval between prior diagnostic Mammotome biopsies and PET-CT was less than 3 weeks, 18.8% for invasive cancer ≤20 mm when the interval was more than 3 weeks, and these results were significant. Mammotome biopsies may therefore affect the detection rate of PET-CT. Invasive cancers ≤20 mm showed a low detection rate, therefore, it is considered to be insufficient to use PET-CT for the detection of early breast cancer. (author)

  2. Can concurrent core biopsy and fine needle aspiration biopsy improve the false negative rate of sonographically detectable breast lesions?

    Directory of Open Access Journals (Sweden)

    Chang Tsai-Wang

    2010-07-01

    Full Text Available Abstract Background The aims of this study were to determine the accuracy of concurrent core needle biopsy (CNB and fine needle aspiration biopsy (FNAB for breast lesions and to estimate the false-negative rate using the two methods combined. Methods Over a seven-year period, 2053 patients with sonographically detectable breast lesions underwent concurrent ultrasound-guided CNB and FNAB. The sonographic and histopathological findings were classified into four categories: benign, indeterminate, suspicious, and malignant. The histopathological findings were compared with the definitive excision pathology results. Patients with benign core biopsies underwent a detailed review to determine the false-negative rate. The correlations between the ultrasonography, FNAB, and CNB were determined. Results Eight hundred eighty patients were diagnosed with malignant disease, and of these, 23 (2.5% diagnoses were found to be false-negative after core biopsy. After an intensive review of discordant FNAB results, the final false-negative rate was reduced to 1.1% (p-value = 0.025. The kappa coefficients for correlations between methods were 0.304 (p-value p-value p-value Conclusions Concurrent CNB and FNAB under ultrasound guidance can provide accurate preoperative diagnosis of breast lesions and provide important information for appropriate treatment. Identification of discordant results using careful radiological-histopathological correlation can reduce the false-negative rate.

  3. Detection of Fundus Lesions Using Classifier Selection

    Science.gov (United States)

    Nagayoshi, Hiroto; Hiramatsu, Yoshitaka; Sako, Hiroshi; Himaga, Mitsutoshi; Kato, Satoshi

    A system for detecting fundus lesions caused by diabetic retinopathy from fundus images is being developed. The system can screen the images in advance in order to reduce the inspection workload on doctors. One of the difficulties that must be addressed in completing this system is how to remove false positives (which tend to arise near blood vessels) without decreasing the detection rate of lesions in other areas. To overcome this difficulty, we developed classifier selection according to the position of a candidate lesion, and we introduced new features that can distinguish true lesions from false positives. A system incorporating classifier selection and these new features was tested in experiments using 55 fundus images with some lesions and 223 images without lesions. The results of the experiments confirm the effectiveness of the proposed system, namely, degrees of sensitivity and specificity of 98% and 81%, respectively.

  4. Imaging inflammatory acne: lesion detection and tracking

    Science.gov (United States)

    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.

  5. Optimization of PET system design for lesion detection

    International Nuclear Information System (INIS)

    Qi, Jinyi

    2000-01-01

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

  6. Optoacoustic detection of thermal lesions

    Science.gov (United States)

    Arsenault, Michel G.; Kolios, Michael C.; Whelan, William M.

    2009-02-01

    Minimally invasive thermal therapy is being investigated as an alternative cancer treatment. It involves heating tissues to greater than 55°C over a period of a few minutes, which results in tissue coagulation. Optoacoustic (OA) imaging is a new imaging technique that involves exposing tissues to pulsed light and detecting the acoustic waves that are generated. In this study, adult bovine liver tissue samples were heated using continuous wave laser energy for various times, then scanned using an optoacoustic imaging system. Large optoacoustic signal variability was observed in the native tissue prior to heating. OA signal amplitude increased with maximum tissue temperature achieved, characterized by a correlation coefficient of 0.63. In this study we show that there are detectable changes in optoacoustic signal strength that arise from tissue coagulation, which demonstrates the potential of optoacoustic technology for the monitoring of thermal therapy delivery.

  7. Automated detection of Lupus white matter lesions in MRI

    Directory of Open Access Journals (Sweden)

    Eloy Roura Perez

    2016-08-01

    Full Text Available 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.

  8. Skin Lesion Analysis towards Melanoma Detection Using Deep Learning Network

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    Yuexiang Li

    2018-02-01

    Full Text Available Skin lesions are a severe disease globally. Early detection of melanoma in dermoscopy images significantly increases the survival rate. However, the accurate recognition of melanoma is extremely challenging due to the following reasons: low contrast between lesions and skin, visual similarity between melanoma and non-melanoma lesions, etc. Hence, reliable automatic detection of skin tumors is very useful to increase the accuracy and efficiency of pathologists. In this paper, we proposed two deep learning methods to address three main tasks emerging in the area of skin lesion image processing, i.e., lesion segmentation (task 1, lesion dermoscopic feature extraction (task 2 and lesion classification (task 3. A deep learning framework consisting of two fully convolutional residual networks (FCRN is proposed to simultaneously produce the segmentation result and the coarse classification result. A lesion index calculation unit (LICU is developed to refine the coarse classification results by calculating the distance heat-map. A straight-forward CNN is proposed for the dermoscopic feature extraction task. The proposed deep learning frameworks were evaluated on the ISIC 2017 dataset. Experimental results show the promising accuracies of our frameworks, i.e., 0.753 for task 1, 0.848 for task 2 and 0.912 for task 3 were achieved.

  9. Skin Lesion Analysis towards Melanoma Detection Using Deep Learning Network.

    Science.gov (United States)

    Li, Yuexiang; Shen, Linlin

    2018-02-11

    Skin lesions are a severe disease globally. Early detection of melanoma in dermoscopy images significantly increases the survival rate. However, the accurate recognition of melanoma is extremely challenging due to the following reasons: low contrast between lesions and skin, visual similarity between melanoma and non-melanoma lesions, etc. Hence, reliable automatic detection of skin tumors is very useful to increase the accuracy and efficiency of pathologists. In this paper, we proposed two deep learning methods to address three main tasks emerging in the area of skin lesion image processing, i.e., lesion segmentation (task 1), lesion dermoscopic feature extraction (task 2) and lesion classification (task 3). A deep learning framework consisting of two fully convolutional residual networks (FCRN) is proposed to simultaneously produce the segmentation result and the coarse classification result. A lesion index calculation unit (LICU) is developed to refine the coarse classification results by calculating the distance heat-map. A straight-forward CNN is proposed for the dermoscopic feature extraction task. The proposed deep learning frameworks were evaluated on the ISIC 2017 dataset. Experimental results show the promising accuracies of our frameworks, i.e., 0.753 for task 1, 0.848 for task 2 and 0.912 for task 3 were achieved.

  10. Skin Lesion Analysis towards Melanoma Detection Using Deep Learning Network

    Science.gov (United States)

    2018-01-01

    Skin lesions are a severe disease globally. Early detection of melanoma in dermoscopy images significantly increases the survival rate. However, the accurate recognition of melanoma is extremely challenging due to the following reasons: low contrast between lesions and skin, visual similarity between melanoma and non-melanoma lesions, etc. Hence, reliable automatic detection of skin tumors is very useful to increase the accuracy and efficiency of pathologists. In this paper, we proposed two deep learning methods to address three main tasks emerging in the area of skin lesion image processing, i.e., lesion segmentation (task 1), lesion dermoscopic feature extraction (task 2) and lesion classification (task 3). A deep learning framework consisting of two fully convolutional residual networks (FCRN) is proposed to simultaneously produce the segmentation result and the coarse classification result. A lesion index calculation unit (LICU) is developed to refine the coarse classification results by calculating the distance heat-map. A straight-forward CNN is proposed for the dermoscopic feature extraction task. The proposed deep learning frameworks were evaluated on the ISIC 2017 dataset. Experimental results show the promising accuracies of our frameworks, i.e., 0.753 for task 1, 0.848 for task 2 and 0.912 for task 3 were achieved. PMID:29439500

  11. Generative adversarial networks for brain lesion detection

    Science.gov (United States)

    Alex, Varghese; Safwan, K. P. Mohammed; Chennamsetty, Sai Saketh; Krishnamurthi, Ganapathy

    2017-02-01

    Manual segmentation of brain lesions from Magnetic Resonance Images (MRI) is cumbersome and introduces errors due to inter-rater variability. This paper introduces a semi-supervised technique for detection of brain lesion from MRI using Generative Adversarial Networks (GANs). GANs comprises of a Generator network and a Discriminator network which are trained simultaneously with the objective of one bettering the other. The networks were trained using non lesion patches (n=13,000) from 4 different MR sequences. The network was trained on BraTS dataset and patches were extracted from regions excluding tumor region. The Generator network generates data by modeling the underlying probability distribution of the training data, (PData). The Discriminator learns the posterior probability P (Label Data) by classifying training data and generated data as "Real" or "Fake" respectively. The Generator upon learning the joint distribution, produces images/patches such that the performance of the Discriminator on them are random, i.e. P (Label Data = GeneratedData) = 0.5. During testing, the Discriminator assigns posterior probability values close to 0.5 for patches from non lesion regions, while patches centered on lesion arise from a different distribution (PLesion) and hence are assigned lower posterior probability value by the Discriminator. On the test set (n=14), the proposed technique achieves whole tumor dice score of 0.69, sensitivity of 91% and specificity of 59%. Additionally the generator network was capable of generating non lesion patches from various MR sequences.

  12. Detection of Helicobacter pylori in Oral Lesions

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    Soussan Irani

    2013-12-01

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

  13. Computerized detection of mass lesions in digital mammograms

    International Nuclear Information System (INIS)

    Yin, F.F.; Giger, M.L.; Doi, K.; Metz, C.E.; Vyborny, C.J.; Schmidt, R.A.

    1989-01-01

    Early detection of breast cancer from the periodic screening of asymptomatic women could reduce breast cancer mortality by at least 40%. The authors are developing a computerized scheme for the detection of mass lesions in digital mammograms as an aid to radiologists in such high volume screening programs. Based on left-right architectural symmetry and gray-level histogram analysis, bilateral subtraction of left and right breast images is performed. False-positive detections included in bilateral-difference images are reduced with various images feature-extraction techniques. The database involves clinical film mammograms digitized by a TV camera and analyzed on a Micro-VAX workstation. Among five different bilateral subtraction techniques investigated, a nonlinear approach provided superior lesion enhancement. Feature-extraction techniques reduced substantially the remaining false-positives. Preliminary results, for 32 pairs of clinical mammograms, yielded a true-positive rate of approximately 95% with a false-positive rate of about 2 per image

  14. Detecting circumscribed lesions with the Hough transform

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Neural network approach to radiologic lesion detection

    International Nuclear Information System (INIS)

    Newman, F.D.; Raff, U.; Stroud, D.

    1989-01-01

    An area of artificial intelligence that has gained recent attention is the neural network approach to pattern recognition. The authors explore the use of neural networks in radiologic lesion detection with what is known in the literature as the novelty filter. This filter uses a linear model; images of normal patterns become training vectors and are stored as columns of a matrix. An image of an abnormal pattern is introduced and the abnormality or novelty is extracted. A VAX 750 was used to encode the novelty filter, and two experiments have been examined

  16. Rate based failure detection

    Science.gov (United States)

    Johnson, Brett Emery Trabun; Gamage, Thoshitha Thanushka; Bakken, David Edward

    2018-01-02

    This disclosure describes, in part, a system management component and failure detection component for use in a power grid data network to identify anomalies within the network and systematically adjust the quality of service of data published by publishers and subscribed to by subscribers within the network. In one implementation, subscribers may identify a desired data rate, a minimum acceptable data rate, desired latency, minimum acceptable latency and a priority for each subscription. The failure detection component may identify an anomaly within the network and a source of the anomaly. Based on the identified anomaly, data rates and or data paths may be adjusted in real-time to ensure that the power grid data network does not become overloaded and/or fail.

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

    International Nuclear Information System (INIS)

    Nakano, Satoko; Ohtsuka, Masahiko; Mibu, Akemi; Karikomi, Masato; Sakata, Hitomi; Yamamoto, Masahiro

    2012-01-01

    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. 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. 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. 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

  18. Optimal reconstructed section thickness for the detection of liver lesions with multidetector CT

    International Nuclear Information System (INIS)

    Soo, G.; Lau, K.K.; Yik, T.; Kutschera, P.

    2010-01-01

    Aim: To evaluate the impact of different reconstructed section thicknesses on liver lesion detection using multidetector computed tomography (CT). Methods: Fifty-three patients were examined using a 16-section CT machine with axial reconstructions provided at 2.5, 5, 7.5, and 10 mm section thicknesses. Images of different reconstructed section thicknesses from different patients were presented in random order to three independent, blinded radiologists for review at multiple sessions. All images were then reviewed by three radiologists in a common session. Consensus was reached following review of the previous interpretation results and results of follow-up imaging regarding the number of true liver lesions (n = 101) for comparison. Results: Mean detection rates were as follows: 93/101 lesions detected with the 2.5 mm section thickness, 98/101 lesions detected at the 5 mm section thickness, 78/101 lesions detected at the 7.5 mm section thickness, and 54/101 lesions detected at the 10 mm section thickness. Lesions missed at the 2.5 mm section thickness were due to masking by image noise. There was particular difficulty detecting subcapsular lesions and lesions adjacent to fissures or the gall bladder at the 7.5 mm and 10 mm section thicknesses. Conclusion: The optimal reconstructed section thickness for lesion detection in the liver was 5 mm.

  19. Automated detection of multiple sclerosis lesions in serial brain MRI

    International Nuclear Information System (INIS)

    Llado, Xavier; Ganiler, Onur; Oliver, Arnau; Marti, Robert; Freixenet, Jordi; Valls, Laia; Vilanova, Joan C.; Ramio-Torrenta, Lluis; Rovira, Alex

    2012-01-01

    Multiple sclerosis (MS) is a serious disease typically occurring in the brain whose diagnosis and efficacy of treatment monitoring are vital. Magnetic resonance imaging (MRI) is frequently used in serial brain imaging due to the rich and detailed information provided. Time-series analysis of images is widely used for MS diagnosis and patient follow-up. However, conventional manual methods are time-consuming, subjective, and error-prone. Thus, the development of automated techniques for the detection and quantification of MS lesions is a major challenge. This paper presents an up-to-date review of the approaches which deal with the time-series analysis of brain MRI for detecting active MS lesions and quantifying lesion load change. We provide a comprehensive reference source for researchers in which several approaches to change detection and quantification of MS lesions are investigated and classified. We also analyze the results provided by the approaches, discuss open problems, and point out possible future trends. Lesion detection approaches are required for the detection of static lesions and for diagnostic purposes, while either quantification of detected lesions or change detection algorithms are needed to follow up MS patients. However, there is not yet a single approach that can emerge as a standard for the clinical practice, automatically providing an accurate MS lesion evolution quantification. Future trends will focus on combining the lesion detection in single studies with the analysis of the change detection in serial MRI. (orig.)

  20. Automated detection of multiple sclerosis lesions in serial brain MRI

    Energy Technology Data Exchange (ETDEWEB)

    Llado, Xavier; Ganiler, Onur; Oliver, Arnau; Marti, Robert; Freixenet, Jordi [University of Girona, Computer Vision and Robotics Group, Girona (Spain); Valls, Laia [Dr. Josep Trueta University Hospital, Department of Radiology, Girona (Spain); Vilanova, Joan C. [Girona Magnetic Resonance Center, Girona (Spain); Ramio-Torrenta, Lluis [Dr. Josep Trueta University Hospital, Institut d' Investigacio Biomedica de Girona, Multiple Sclerosis and Neuroimmunology Unit, Girona (Spain); Rovira, Alex [Vall d' Hebron University Hospital, Magnetic Resonance Unit, Department of Radiology, Barcelona (Spain)

    2012-08-15

    Multiple sclerosis (MS) is a serious disease typically occurring in the brain whose diagnosis and efficacy of treatment monitoring are vital. Magnetic resonance imaging (MRI) is frequently used in serial brain imaging due to the rich and detailed information provided. Time-series analysis of images is widely used for MS diagnosis and patient follow-up. However, conventional manual methods are time-consuming, subjective, and error-prone. Thus, the development of automated techniques for the detection and quantification of MS lesions is a major challenge. This paper presents an up-to-date review of the approaches which deal with the time-series analysis of brain MRI for detecting active MS lesions and quantifying lesion load change. We provide a comprehensive reference source for researchers in which several approaches to change detection and quantification of MS lesions are investigated and classified. We also analyze the results provided by the approaches, discuss open problems, and point out possible future trends. Lesion detection approaches are required for the detection of static lesions and for diagnostic purposes, while either quantification of detected lesions or change detection algorithms are needed to follow up MS patients. However, there is not yet a single approach that can emerge as a standard for the clinical practice, automatically providing an accurate MS lesion evolution quantification. Future trends will focus on combining the lesion detection in single studies with the analysis of the change detection in serial MRI. (orig.)

  1. Endoscopic detection rate of sessile serrated lesions in Lynch syndrome patients is comparable with an age- and gender-matched control population: case-control study with expert pathology review.

    Science.gov (United States)

    Vleugels, Jasper L A; Sahin, Husna; Hazewinkel, Yark; Koens, Lianne; van den Berg, Jose G; van Leerdam, Monique E; Dekker, Evelien

    2018-05-01

    Carcinogenesis in Lynch syndrome involves fast progression of adenomas to colorectal cancer (CRC) because of microsatellite instability. The role of sessile serrated lesions (SSLs) and the serrated neoplasia pathway in these patients is unknown. The aim of this matched case-control study was to compare endoscopic detection rates and distribution of SSLs in Lynch syndrome patients with a matched control population. We collected data of Lynch syndrome patients with a proven germline mutation who underwent colonoscopy between January 2011 and April 2016 in 2 tertiary referral hospitals. Control subjects undergoing elective colonoscopy from 2011 and onward for symptoms or surveillance were selected from a prospectively collected database. Patients were matched 1:1 for age, gender, and index versus surveillance colonoscopy. An expert pathology review of serrated polyps was performed. The primary outcomes included the detection rates and distribution of SSLs. We identified 321 patients with Lynch syndrome who underwent at least 1 colonoscopy. Of these, 223 Lynch syndrome patients (mean age, 49.3; 59% women; index colonoscopy, 56%) were matched to 223 control subjects. SSLs were detected in 7.6% (95% confidence interval, 4.8-11.9) of colonoscopies performed in Lynch syndrome patients and in 6.7% (95% confidence interval, 4.1-10.8) of control subjects (P = .86). None of the detected SSLs in Lynch syndrome patients contained dysplasia. The detection rate of SSLs in Lynch syndrome patients undergoing colonoscopy is comparable with a matched population. These findings suggest that the role of the serrated neoplasia pathway in CRC development in Lynch syndrome seems to be comparable with that in the general population. Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  2. Stereotaxic cytology of nonpalpable lesions detected at mammography

    International Nuclear Information System (INIS)

    Ciatto, S.; Rosselli del Turco, M.; Bravetti, P.; Catarzi, S.

    1991-01-01

    The authors report on 791 consecutive cases undergoing stereotaxic cytology for non palpable lesions detected at mammography. Histologic diagnosis (malignant = 179, benign = 107) or mammographic folow-up after at least one year (benign = 275) was available in 561 cases. The overall inadequacy rate of stereotaxic cytology was 0.21, and dependent on lesion type (benign = 0.25, malignant = 0.13 p<0.001) and on sampling operator experience (range 0.17-0.31, p<0.001). Sensitivity (dubious+positive, after exclusion of inadequates) was 0.83 and dependent on histologic type (infiltrating = 0.87, intraductal = 0.68). Specificity (negative/benign, after exclusion of inadequates) was 0.96. Stereotaxic cytology helped in reducing the number of unnecessary beningn biopsies and the biopsy ratio was 0.6 benign to 1 malignant biopsy. In cases with moderate suspicion at mammography the radiologist felt reassured by negative cytology and advised mammographic control rather than surgical biopsy. Cytology was determinant in advising surgical biopsy in 9 cancer cases whereas the absence of cytologic positivity contributed to diagnostic delay in 2 cancer cases. Overall, stereotaxic cytology allowed a relevant reduction of unnecessary benign biopsies and should be routinely employed in the diagnostic work-up of nonpalpable lesions detected at mammography

  3. Incidentally Detected Enhancing Breast Lesions on Chest Computed Tomography

    International Nuclear Information System (INIS)

    Lin, Wen Chiung; Hsu, Hsian He; Yu, Jyh Cherng; Hsu, Giu Cheng; Yu, Cheng Ping; Chang, Tsun Hou; Huang, Guo Shu; Li, Chao Shiang

    2011-01-01

    To evaluate the nature and imaging appearance of incidental enhancing breast lesions detected on a routine contrast-enhanced chest CT. Twenty-three patients with incidental enhancing breast lesions on contrast-enhanced chest CT were retrospectively reviewed. The breast lesions were reviewed by unenhanced and enhanced CT, and evaluated by observing the shapes, margins, enhancement patterns and backgrounds of breast lesions. A histopathologic diagnosis or long-term follow-up served as reference standard. Sixteen (70%) patients had malignant breast lesions and seven (30%) had benign lesions. In 10 patients, the breast lesions were exclusively detected on contrast-enhanced CT. Using unenhanced CT, breast lesions with fi broglandular backgrounds were prone to be obscured (p < 0.001). Incidental primary breast cancer showed an non-significant trend of a higher percentage irregular margin (p = 0.056). All of the four incidental breast lesions with non-mass-like enhancement were proven to be malignant. Routine contrast-enhanced chest CT can reveal sufficient details to allow for the detection of unsuspected breast lesions, in which some cases may be proven as malignant. An irregular margin of incidental enhancing breast lesion can be considered a suggestive sign of malignancy

  4. A soft kinetic data structure for lesion border detection.

    Science.gov (United States)

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

    2010-06-15

    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. 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.

  5. Detection activity assessment and diagnosis of dental caries lesions

    DEFF Research Database (Denmark)

    Braga, Mariana M; Mendes, Fausto M; Ekstrand, Kim R

    2010-01-01

    This article reviews the current methods for detection and assessment of caries lesions focusing on applicability for daily clinical practice. The end point is to arrive at a diagnosis for each caries lesion. Visual inspection aided by a ball-ended probe is essential for caries lesions assessment...... and the method must be used for all patients. Use of indices, for example, the International Caries Detection and Assessment System (ICDAS), can improve the performance of this method. Using visual inspection, the clinician must decide about the presence, severity and activity of lesions. After this process...

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  8. Multispectral detection of cutaneous lesions using spectroscopy and microscopy approaches

    Science.gov (United States)

    Borisova, E.; Genova-Hristova, Ts.; Troyanova, P.; Pavlova, E.; Terziev, I.; Semyachkina-Glushkovskaya, O.; Lomova, M.; Genina, E.; Stanciu, G.; Tranca, D.; Avramov, L.

    2018-02-01

    Autofluorescence, diffuse-reflectance and transmission spectral, and microscopic measurements were made on different cutaneous neoplastic lesions, namely basal cell carcinoma, squamous cell carcinoma, malignant melanoma, and dysplastic and benign lesions related. Spectroscopic measurements were made on ex vivo tissue samples, and confocal microscopy investigations were made on thin tissue slices. Fluorescence spectra obtained reveal statistically significant differences between the different benign, dysplastic and malignant lesions by the level of emission intensity, as well by spectral shape, which are fingerprints applicable for differentiation algorithms. In reflectance mode the most significant differences are related to the influence of skin pigments - melanin and hemoglobin. Transmission spectroscopy mode gave complementary optical properties information about the tissue samples investigated to that one of reflectance and absorption spectroscopy. Using autofluorescence detection of skin lesions we obtain very good diagnostic performance for distinguishing of nonmelanoma lesions. Using diffuse reflectance and transmission spectroscopy we obtain significant tool for pigmented pathologies differentiation, but it is a tool with moderate sensitivity for non-melanoma lesions detection. One could rapidly increase the diagnostic accuracy of the received combined "optical biopsy" method when several spectral detection techniques are applied in common algorithm for lesions' differentiation. Specific spectral features observed in each type of lesion investigated on micro and macro level would be presented and discussed. Correlation between the spectral data received and the microscopic features observed would be discussed in the report.

  9. Detection and monitoring of early caries lesions

    DEFF Research Database (Denmark)

    Pretty, I A; Ekstrand, K R

    2016-01-01

    and co-workers from 2013 and this still represents the current state of the science in relation to caries detection and monitoring. The review described among others, visible detection systems, image-based detection systems and point-measurement approaches. RESULTS: The current evidence base suggests...... that while there are numerous devices or technology-enabled detection systems, the use of a careful, methodical visual inspection of clean, dry teeth, supplemented where indicated by radiographic views, remains the standard of care in caries detection and diagnostics. Further, it is possible by means...... to the clinician and the patient for whom it may be a useful educational and motivational tool. CONCLUSIONS: Recommendations are presented that can be adopted and adapted to local circumstances and that are both substantiated by evidence and promote a clear, simple and consistent approach to caries detection...

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

    International Nuclear Information System (INIS)

    Shin, Jung Hee; Han, Boo Kyung; Choe, Yeon Hyeon; Ko, Kyung Ran; Choi, Nami

    2007-01-01

    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. 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. 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. 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

  11. Automated detection of fundus photographic red lesions in diabetic retinopathy.

    Science.gov (United States)

    Larsen, Michael; Godt, Jannik; Larsen, Nicolai; Lund-Andersen, Henrik; Sjølie, Anne Katrin; Agardh, Elisabet; Kalm, Helle; Grunkin, Michael; Owens, David R

    2003-02-01

    To compare a fundus image-analysis algorithm for automated detection of hemorrhages and microaneurysms with visual detection of retinopathy in patients with diabetes. Four hundred fundus photographs (35-mm color transparencies) were obtained in 200 eyes of 100 patients with diabetes who were randomly selected from the Welsh Community Diabetic Retinopathy Study. A gold standard reference was defined by classifying each patient as having or not having diabetic retinopathy based on overall visual grading of the digitized transparencies. A single-lesion visual grading was made independently, comprising meticulous outlining of all single lesions in all photographs and used to develop the automated red lesion detection system. A comparison of visual and automated single-lesion detection in replicating the overall visual grading was then performed. Automated red lesion detection demonstrated a specificity of 71.4% and a resulting sensitivity of 96.7% in detecting diabetic retinopathy when applied at a tentative threshold setting for use in diabetic retinopathy screening. The accuracy of 79% could be raised to 85% by adjustment of a single user-supplied parameter determining the balance between the screening priorities, for which a considerable range of options was demonstrated by the receiver-operating characteristic (area under the curve 90.3%). The agreement of automated lesion detection with overall visual grading (0.659) was comparable to the mean agreement of six ophthalmologists (0.648). Detection of diabetic retinopathy by automated detection of single fundus lesions can be achieved with a performance comparable to that of experienced ophthalmologists. The results warrant further investigation of automated fundus image analysis as a tool for diabetic retinopathy screening.

  12. Lesion detection and quantitation of positron emission mammography

    International Nuclear Information System (INIS)

    Qi, Jinyi; Huesman, Ronald H.

    2001-01-01

    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

  13. Detection of pathogens from periodontal lesions

    Directory of Open Access Journals (Sweden)

    Malheiros Veruska de João

    2004-01-01

    Full Text Available OBJECTIVE: To comparatively detect A. actinomycetemcomitans and F. nucleatum from periodontal and healthy sites. METHODS: Subgingival clinical samples from 50 periodontitis adult patients and 50 healthy subjects were analyzed. Both organisms were isolated using a trypticase soy agar-bacitracin-vancomycin (TSBV medium and detected by PCR. Conventional biochemical tests were used for bacteria identification. RESULTS: A. actinomycetemcomitans and F. nucleatum were isolated in 18% and 20% of the patients, respectively, and in 2% and 24% of healthy subjects. Among A. actinomycetemcomitans isolates, biotype II was the most prevalent. Primer pair AA was 100% sensitive in the detection of A. actinomycetemcomitans from both subject groups. Primers ASH and FU were also 100% sensitive to detect this organism in healthy subject samples. Primer pair FN5047 was more sensitive to detect F. nucleatum in patients or in healthy samples than primer 5059S. Primers ASH and 5059S were more specific in the detection of A. actinomycetemcomitans and F. nucleatum, respectively, in patients and in healthy subject samples. CONCLUSIONS: PCR is an effective tool for detecting periodontal pathogens in subgingival samples, providing a faster and safer diagnostic tool of periodontal diseases. The method's sensitivity and specificity is conditioned by the choice of the set of primers used.

  14. Detection of inflammatory lesions with radiolabelled immunoglobulins

    International Nuclear Information System (INIS)

    Blok, D.; Rijksuniversiteit Leiden; Ogtrop, M. van; Arndt, J.W.; Camps, J.A.J.; Feitsma, R.I.J.; Pauwels, E.K.J.

    1990-01-01

    Previous reports on the use of radiolabelled immunoglobulins led us to undertake a pilot experiment in an animal model to investigate the potentials sodium pertechnate Tc 99m-immunoglobulin scintigraphy in the detection of infectious foci. Mice infected in one leg with staphylococcus infection in were injected with sodium pertechnote Tc 99m-immunoglobulin, albumin aggregated technetium Tc 99m or gallium citrate Ga 67. The results obtained by scintigraphy suggested a specific accumulation of radiolabelled immunoglobulin at the site of infection. Visualization of the infection and the image quality, especially the 6- and 24-h images, were clearly enhanced after the use of immunoglobulin preparations as compared with those labelled with gallium. (orig.)

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

    Science.gov (United States)

    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.

  16. Automated Breast Ultrasound Lesions Detection using Convolutional Neural Networks.

    Science.gov (United States)

    Yap, Moi Hoon; Pons, Gerard; Marti, Joan; Ganau, Sergi; Sentis, Melcior; Zwiggelaar, Reyer; Davison, Adrian K; Marti, Robert

    2017-08-07

    Breast lesion detection using ultrasound imaging is considered an important step of Computer-Aided Diagnosis systems. Over the past decade, researchers have demonstrated the possibilities to automate the initial lesion detection. However, the lack of a common dataset impedes research when comparing the performance of such algorithms. This paper proposes the use of deep learning approaches for breast ultrasound lesion detection and investigates three different methods: a Patch-based LeNet, a U-Net, and a transfer learning approach with a pretrained FCN-AlexNet. Their performance is compared against four state-of-the-art lesion detection algorithms (i.e. Radial Gradient Index, Multifractal Filtering, Rule-based Region Ranking and Deformable Part Models). In addition, this paper compares and contrasts two conventional ultrasound image datasets acquired from two different ultrasound systems. Dataset A comprises 306 (60 malignant and 246 benign) images and Dataset B comprises 163 (53 malignant and 110 benign) images. To overcome the lack of public datasets in this domain, Dataset B will be made available for research purposes. The results demonstrate an overall improvement by the deep learning approaches when assessed on both datasets in terms of True Positive Fraction, False Positives per image, and F-measure.

  17. Medical Imaging Lesion Detection Based on Unified Gravitational Fuzzy Clustering

    Directory of Open Access Journals (Sweden)

    Jean Marie Vianney Kinani

    2017-01-01

    Full Text Available We develop a swift, robust, and practical tool for detecting brain lesions with minimal user intervention to assist clinicians and researchers in the diagnosis process, radiosurgery planning, and assessment of the patient’s response to the therapy. We propose a unified gravitational fuzzy clustering-based segmentation algorithm, which integrates the Newtonian concept of gravity into fuzzy clustering. We first perform fuzzy rule-based image enhancement on our database which is comprised of T1/T2 weighted magnetic resonance (MR and fluid-attenuated inversion recovery (FLAIR images to facilitate a smoother segmentation. The scalar output obtained is fed into a gravitational fuzzy clustering algorithm, which separates healthy structures from the unhealthy. Finally, the lesion contour is automatically outlined through the initialization-free level set evolution method. An advantage of this lesion detection algorithm is its precision and its simultaneous use of features computed from the intensity properties of the MR scan in a cascading pattern, which makes the computation fast, robust, and self-contained. Furthermore, we validate our algorithm with large-scale experiments using clinical and synthetic brain lesion datasets. As a result, an 84%–93% overlap performance is obtained, with an emphasis on robustness with respect to different and heterogeneous types of lesion and a swift computation time.

  18. Texture alteration detection in bitemporal images of lesions with psoriasis

    DEFF Research Database (Denmark)

    Maletti, Gabriela Mariel; Ersbøll, Bjarne Kjær

    2003-01-01

    The objective of this work is to explore the feasibility of quantifying textural change between pairs of segmented patterns without registering them. The Multi-variate Alteration Detection (M.A.D.) Transform is applied to a texture model constructed with the data of segmented psoriasis lesions im...... images. The texture model is Haralick's co-occurrence matrix, which is computed and normalized for each single band with the equalized data of a given lesion. The contribution of each single color band to the textural change is analyzed....

  19. Cylindrical SUV distribution model for detecting skin lesions in body trunk FDG-PET/CT images

    International Nuclear Information System (INIS)

    Nemoto, Mitsutaka; Nomura, Yukihiro; Masutani, Yoshitaka; Yoshikawa, Takeharu; Hayashi, Naoto; Yoshioka, Naoki; Ohtomo, Kuni; Hanaoka, Shouhei

    2010-01-01

    We have been developing a computerized detection method for skin lesions in body trunk fluorodeoxyglucose-positron emission tomography (FDG-PET)/CT images. Spots on the skin with a high standard uptake value (SUV) are due not only to glucose metabolism in skin lesions but also to the physiological metabolism of organs near the skin. The distribution pattern of regional SUV on the skin is important information for the differential diagnosis of such high-SUV spots. In this study, we have developed a new skin lesion detection method based on a cylindrical SUV distribution model of the skin. The shape of the SUV distribution model is an approximation of the body trunk, and the SUV distribution model includes standard values for regional skin SUV. Classifier ensembles based on CT image features, SUV features, and subtraction features between the SUVs in FDG-PET images and the values in the SUV distribution model are used to extract and classify candidate regions for skin lesions. In a study of skin lesion detection using FDG-PET/CT images in 36 clinical cases, the true-positive rate was 61.7%, with 11.7 false-positive regions per case. The training results of the classifier ensemble for extracting and classifying candidate regions showed the effective features for detecting skin lesions in the study. (author)

  20. Detection of white matter lesion regions in MRI using SLIC0 and convolutional neural network.

    Science.gov (United States)

    Diniz, Pedro Henrique Bandeira; Valente, Thales Levi Azevedo; Diniz, João Otávio Bandeira; Silva, Aristófanes Corrêa; Gattass, Marcelo; Ventura, Nina; Muniz, Bernardo Carvalho; Gasparetto, Emerson Leandro

    2018-04-19

    White matter lesions are non-static brain lesions that have a prevalence rate up to 98% in the elderly population. Because they may be associated with several brain diseases, it is important that they are detected as soon as possible. Magnetic Resonance Imaging (MRI) provides three-dimensional data with the possibility to detect and emphasize contrast differences in soft tissues, providing rich information about the human soft tissue anatomy. However, the amount of data provided for these images is far too much for manual analysis/interpretation, representing a difficult and time-consuming task for specialists. This work presents a computational methodology capable of detecting regions of white matter lesions of the brain in MRI of FLAIR modality. The techniques highlighted in this methodology are SLIC0 clustering for candidate segmentation and convolutional neural networks for candidate classification. The methodology proposed here consists of four steps: (1) images acquisition, (2) images preprocessing, (3) candidates segmentation and (4) candidates classification. The methodology was applied on 91 magnetic resonance images provided by DASA, and achieved an accuracy of 98.73%, specificity of 98.77% and sensitivity of 78.79% with 0.005 of false positives, without any false positives reduction technique, in detection of white matter lesion regions. It is demonstrated the feasibility of the analysis of brain MRI using SLIC0 and convolutional neural network techniques to achieve success in detection of white matter lesions regions. Copyright © 2018. Published by Elsevier B.V.

  1. IMAGE PROCESSING FOR DETECTION OF ORAL WHITE SPONGE NEVUS LESIONS

    Directory of Open Access Journals (Sweden)

    Rajdeep Mitra

    2016-12-01

    Full Text Available White Sponge Nevus is a rear hereditary disease in human causes incurable white lesions in oral mucosa. Appropriate history, clinical examination along with biopsy and cytological studies are helpful for diagnosis of this disorder. Identification can also be made in alternative way by applying image processing technique using Watershed segmentation with MATLAB software. The applied techniques are effective and reliable for early accurate detection of the disease as alternative of expertise clinical and time taking laboratory investigations.

  2. Visual Inspection Displays Good Accuracy for Detecting Caries Lesions

    DEFF Research Database (Denmark)

    Twetman, Svante

    2015-01-01

    /QUESTION: To evaluate the overall accuracy of visual methods for detecting caries lesions. SOURCE OF FUNDING: Brazilian government (Process 2012/17888-1). TYPE OF STUDY/DESIGN: Systematic review with meta-analysis of data LEVEL OF EVIDENCE: Level 1: Good-quality, patient-oriented evidence STRENGTH OF RECOMMENDATION......ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Visual inspection for caries detection: a systematic review and meta-analysis. Gimenez T, Piovesan C, Braga MM, Raggio DP, Deery C, Ricketts DN, Ekstrand DR, Mendes FM. J Dent Res 2015;94(7):895-904. REVIEWER: Svante Twetman, DDS, PhD, Odont Dr PURPOSE...

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

    International Nuclear Information System (INIS)

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

    2013-01-01

    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. 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. 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. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Hun; Kang, Bong Joo; Choi, Byung Gil; Choi, Jae Jung; Lee, Ji Hye [Department of Radiology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Song, Byung Joo; Choe, Byung Joo [Department of General Surgery, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Park, Sarah [Department of Internal Medicine, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Kim, Hyunbin [CMC Clinical Research Coordinating Center, College of Medicine, The Catholic University of Korea, Seoul 137-701 (Korea, Republic of)

    2013-07-01

    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. 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. 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. 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.

  5. Proliferative changes in nonpalpable breast lesions detected by mammography

    International Nuclear Information System (INIS)

    Vega, A.; Delgado, A.; Ortega, E.; Garijo, F.; Mosquera, J.; Sogo, C.; Alvarez, A.

    2000-01-01

    To analyze retrospectively the radiological findings in nonpalpable breast lesions detected by mammography that lead to the performance of surgical biopsy, resulting in a histological diagnosis of proliferative breast disease with and without atypia. From two Spanish hospitals, 421 women with 429 biopsies indicative of the presence of proliferative breast disease with and without atypia were selected out of a total of 1252 surgical biopsies in nonpalpable lesions that proved to be benign. Age, personal and familial history of breast cancer, reason for requesting the mammography and radiological findings that had indicated the need for surgical biopsy were recorded for each patient. The diagnosis was proliferative breast disease (epithelial hyperplasia) in 347 women with 354 biopsies and atypical hyperplasia in the remaining 74 women with 75 biopsies, representing 28% and 6%, respectively, of the 1252 biopsies of lesions found to be benign. In 221 of the 354 cases of epithelial hyperplasia (62%) and 45 of the 75 cases of atypical hyperplasia (60%), the presence of calcifications was the most common radiological findings leading to biopsy (p<0.05). Parenchymal distortion, with or without calcifications, was the second most common radiological sign. The histological study revealed a close relationship between these proliferative events and radial scars. Calcifications are the radiological finding that most frequently indicate the need for surgical biopsy in nonpalpable lesions that results in a diagnosis of proliferative breast disease with and without atypia. (Author) 12 refs

  6. Off-site evaluation of liver lesion detection by Gd-BOPTA-enhanced MR imaging

    International Nuclear Information System (INIS)

    Gehl, H.B.; Bourne, M.; Grazioli, L.; Moeller, A.; Lodemann, K.P.

    2001-01-01

    The aim of this study was to determine the efficacy of Gd-BOPTA-enhanced MRI in liver lesion detection in comparison with unenhanced MRI and dynamic CT. The image sets of 148 of 151 patients enrolled in a multicenter German phase-III trial were evaluated by two independent radiologists unaffiliated with the investigating centers. Patients underwent a routine MRI protocol comprising T2- and T1-weighted spin-echo and T1-weighted gradient-echo (GE) sequences pre and 1 h post 0.1 mmol/kg Gd-BOPTA (Bracco-Byk Gulden, Konstanz, Germany). Additionally, a serial T1-weighted GE scan was performed after administration of the first half of the dose. All patients underwent dynamic contrast-enhanced CT. The evaluation was performed with regard to the number and size of lesions detected per patient by each modality or sequence. Furthermore, all pre CM and pre + post CM image sets were analyzed for number of lesions per patient. Both readers detected significantly more lesions in the contrast-enhanced image set compared with the unenhanced image set (32 and 39 %, respectively; p < 0.0001). While contrast-enhanced CT detected a similar number of lesions to unenhanced MRI, it was clearly inferior to contrast-enhanced MRI (reader 1: p = 0.0117; reader 2: p = 0.0225). Of the T1-weighted scans performed, the dynamic and late T1-weighted GE exams contributed most to the increased lesion detection rate (reader 1: p = 0.0007; reader 2: p = 0.0037). The size of the smallest lesion detected by means of MRI was significantly larger in the pre-CM image sets than in the pre + post CM image sets (reader 1: p = 0.001; reader 2: p < 0.0001). Gd-BOPTA-enhanced MRI detected significantly smaller lesions than contrast-enhanced CT (reader 1: p = 0.0117; reader 2: p = 0.0925). Gd-BOPTA-enhanced MR imaging improves liver lesion detection significantly over unenhanced MRI and dynamic CT. (orig.)

  7. Off-site evaluation of liver lesion detection by Gd-BOPTA-enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gehl, H.B. [Inst. of Diagnostic Radiology, Medical Univ. of Luebeck (Germany); Bourne, M. [Dept. of Radiology, Univ. Hospital of Wales, Cardiff (United Kingdom); Grazioli, L. [Dept. of Radiology, Univ. of Brescia (Italy); Moeller, A. [MEDIDATA GmbH, Konstanz (Germany); Lodemann, K.P. [BRACCO-BYK GULDEN GmbH, Konstanz (Germany)

    2001-02-01

    The aim of this study was to determine the efficacy of Gd-BOPTA-enhanced MRI in liver lesion detection in comparison with unenhanced MRI and dynamic CT. The image sets of 148 of 151 patients enrolled in a multicenter German phase-III trial were evaluated by two independent radiologists unaffiliated with the investigating centers. Patients underwent a routine MRI protocol comprising T2- and T1-weighted spin-echo and T1-weighted gradient-echo (GE) sequences pre and 1 h post 0.1 mmol/kg Gd-BOPTA (Bracco-Byk Gulden, Konstanz, Germany). Additionally, a serial T1-weighted GE scan was performed after administration of the first half of the dose. All patients underwent dynamic contrast-enhanced CT. The evaluation was performed with regard to the number and size of lesions detected per patient by each modality or sequence. Furthermore, all pre CM and pre + post CM image sets were analyzed for number of lesions per patient. Both readers detected significantly more lesions in the contrast-enhanced image set compared with the unenhanced image set (32 and 39 %, respectively; p < 0.0001). While contrast-enhanced CT detected a similar number of lesions to unenhanced MRI, it was clearly inferior to contrast-enhanced MRI (reader 1: p = 0.0117; reader 2: p = 0.0225). Of the T1-weighted scans performed, the dynamic and late T1-weighted GE exams contributed most to the increased lesion detection rate (reader 1: p = 0.0007; reader 2: p = 0.0037). The size of the smallest lesion detected by means of MRI was significantly larger in the pre-CM image sets than in the pre + post CM image sets (reader 1: p = 0.001; reader 2: p < 0.0001). Gd-BOPTA-enhanced MRI detected significantly smaller lesions than contrast-enhanced CT (reader 1: p = 0.0117; reader 2: p = 0.0925). Gd-BOPTA-enhanced MR imaging improves liver lesion detection significantly over unenhanced MRI and dynamic CT. (orig.)

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

    Science.gov (United States)

    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.

  9. Detection of intaoral lesions using a fluorescence camera

    Science.gov (United States)

    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.

  10. Management of breast lesions detectable only on MRI

    International Nuclear Information System (INIS)

    Siegmann-Luz, K.C.; Bahrs, S.D.; Preibsch, H.; Hattermann, V.; Claussen, C.D.

    2014-01-01

    Breast MR imaging has become established as the most sensitive imaging method for diagnosing breast cancer. As a result of the increasing examination volume and improved image quality, the number of breast lesions detected only on MRI and requiring further clarification has risen in recent years. According to the S3-guideline 'Diagnosis, Therapy, and Follow-Up of Breast Cancer' as revised in July 2012, institutions performing breast MRI should provide the option of an MRI-guided intervention for clarification. This review describes the indications, methods and results of MRI-guided interventions for the clarification of breast lesions only visible on MRI. Recent guidelines and study results are also addressed and alternative methods and pitfalls are presented. (orig.)

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

    Science.gov (United States)

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

    2018-03-01

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

  12. Improved Detection of Microsatellite Instability in Early Colorectal Lesions.

    Directory of Open Access Journals (Sweden)

    Jeffery W Bacher

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

  13. A subtraction pipeline for automatic detection of new appearing multiple sclerosis lesions in longitudinal studies

    Energy Technology Data Exchange (ETDEWEB)

    Ganiler, Onur; Oliver, Arnau; Diez, Yago; Freixenet, Jordi; Llado, Xavier [University of Girona, VICOROB Computer Vision and Robotics Group, Girona (Spain); Vilanova, Joan C. [Girona Magnetic Resonance Center, Girona (Spain); Beltran, Brigitte [Dr. Josep Trueta University Hospital, Institut d' Investigacio Biomedica de Girona, Girona (Spain); Ramio-Torrenta, Lluis [Dr. Josep Trueta University Hospital, Institut d' Investigacio Biomedica de Girona, Multiple Sclerosis and Neuroimmunology Unit, Girona (Spain); Rovira, Alex [Vall d' Hebron University Hospital, Magnetic Resonance Unit, Department of Radiology, Barcelona (Spain)

    2014-05-15

    Time-series analysis of magnetic resonance images (MRI) is of great value for multiple sclerosis (MS) diagnosis and follow-up. In this paper, we present an unsupervised subtraction approach which incorporates multisequence information to deal with the detection of new MS lesions in longitudinal studies. The proposed pipeline for detecting new lesions consists of the following steps: skull stripping, bias field correction, histogram matching, registration, white matter masking, image subtraction, automated thresholding, and postprocessing. We also combine the results of PD-w and T2-w images to reduce false positive detections. Experimental tests are performed in 20 MS patients with two temporal studies separated 12 (12M) or 48 (48M) months in time. The pipeline achieves very good performance obtaining an overall sensitivity of 0.83 and 0.77 with a false discovery rate (FDR) of 0.14 and 0.18 for the 12M and 48M datasets, respectively. The most difficult situation for the pipeline is the detection of very small lesions where the obtained sensitivity is lower and the FDR higher. Our fully automated approach is robust and accurate, allowing detection of new appearing MS lesions. We believe that the pipeline can be applied to large collections of images and also be easily adapted to monitor other brain pathologies. (orig.)

  14. Automatic detection of breast lesions with MIBI-Tc99m scintimammography using a novelty filter

    International Nuclear Information System (INIS)

    Costa, M.; Moura, L.

    1996-01-01

    An automatic method for detecting breast lesion in scintimammography is described. It is reported that the proposed method not only detects lesions but also classifies them as benign or malignant. The detection method makes use of Kohonen's novelty filter and the classification method is obtained by the analysis of an identified lesion mean profile. The method was able to detect all lesions presented in the scintimammogram and to correctly classify 16 out of 17 malignant lesions and 15 out of 17 benign lesions. The sensitivity of the method was 94,12% and specificity was 88,24%

  15. Reporting and management of breast lesions detected using MRI

    International Nuclear Information System (INIS)

    Dall, B.J.G.; Vinnicombe, S.; Gilbert, F.J.

    2011-01-01

    Magnetic resonance imaging (MRI) is the most accurate technique for diagnosing and delineating the extent of both invasive and in-situ breast cancer and is increasingly being used as part of the preoperative work-up to assess the local extent of disease. It is proving invaluable in providing information that allows successful single-stage surgery. An inevitable consequence of the high sensitivity of MRI is that it will identify additional lesions that may or may not represent significant extra disease. This may complicate and delay the preoperative process. This paper outlines a strategy for managing MRI-detected lesions to optimize the benefits of breast MRI as a local staging tool while minimizing the false-positive diagnoses. It discusses the importance of good technique to reduce the number of indeterminate lesions. Methods to refine the patient pathway to minimize delays are discussed. The format of MRI reporting is discussed in detail as is the usefulness of discussion of cases at multidisciplinary meetings. Illustrative cases are used to clarify the points made.

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  17. High rate of benign histology in radiologically suspect renal lesions

    DEFF Research Database (Denmark)

    Lindkvist Pedersen, Christina; Winck-Flyvholm, Lili; Dahl, Claus

    2014-01-01

    INTRODUCTION: The objective of this study was to determine the incidence of benign renal lesions for clinically localised renal masses and the need for new diagnostic procedures to assess these lesions. MATERIAL AND METHODS: This retrospective study included patients who underwent partial or radi...

  18. Detection of oral early cancerous lesion by using polarization-sensitive optical coherence tomography: mice model

    Science.gov (United States)

    Lee, Hong-Yi; Chen, Ping-Hsien; Lee, Tzu-Han; Chang, Kuo-Wei; Kuo, Wen-Chuan

    2018-02-01

    Oral cancer is the 11th most common cancer worldwide, especially in a male adult. The median age of death in oral cancer was 55 years, 10-20 years earlier than other cancers. Presently, oral cancer is often found in late stage, because the lesion is often flat in early stage and is difficult to diagnose under traditional white light imaging. The only definitive method for determining cancer is an invasive biopsy and then using histology examination. How to detect precancerous lesions or early malignant lesions is an important issue for improving prognosis of oral cancer. Optical coherence tomography (OCT) is a new optical tool for diagnosing early malignant lesions in the skin or gastrointestinal tract recently. Here we report a new method for detecting precancerous or early malignant oral lesions by using swept source polarization-sensitive optical coherence tomography (PS-OCT) with center-wavelength 1310 nm, bandwidth 110 nm and 100 kHz swept rate. We used all single-mode fiber design to detect the change of birefringence information in the epithelium structure. This system has an advantage that enables measurement of backscattered intensity and birefringence simultaneously with only one A-scan per transverse location. In preliminary result, we computed the slope of the every A-scan signal in tissue part using a linear-curve fitting in backscattered intensity and birefringence on the enface. In this research, we used an oral cancer mice model for observing the change of structure and birefringence properties in different stages of oral cancer mice. We presented the parametric enface imaging that can detect the early oral malignant lesions.

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

    Science.gov (United States)

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

    2017-12-01

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

  20. Lesion detection performance: comparative analysis of low-dose CT data of the chest on two hybrid imaging systems.

    Science.gov (United States)

    Jessop, Maryam; Thompson, John D; Coward, Joanne; Sanderud, Audun; Jorge, José; de Groot, Martijn; Lança, Luís; Hogg, Peter

    2015-03-01

    Incidental findings on low-dose CT images obtained during hybrid imaging are an increasing phenomenon as CT technology advances. Understanding the diagnostic value of incidental findings along with the technical limitations is important when reporting image results and recommending follow-up, which may result in an additional radiation dose from further diagnostic imaging and an increase in patient anxiety. This study assessed lesions incidentally detected on CT images acquired for attenuation correction on two SPECT/CT systems. An anthropomorphic chest phantom containing simulated lesions of varying size and density was imaged on an Infinia Hawkeye 4 and a Symbia T6 using the low-dose CT settings applied for attenuation correction acquisitions in myocardial perfusion imaging. Twenty-two interpreters assessed 46 images from each SPECT/CT system (15 normal images and 31 abnormal images; 41 lesions). Data were evaluated using a jackknife alternative free-response receiver-operating-characteristic analysis (JAFROC). JAFROC analysis showed a significant difference (P detection, with the figures of merit being 0.599 (95% confidence interval, 0.568, 0.631) and 0.810 (95% confidence interval, 0.781, 0.839) for the Infinia Hawkeye 4 and Symbia T6, respectively. Lesion detection on the Infinia Hawkeye 4 was generally limited to larger, higher-density lesions. The Symbia T6 allowed improved detection rates for midsized lesions and some lower-density lesions. However, interpreters struggled to detect small (5 mm) lesions on both image sets, irrespective of density. Lesion detection is more reliable on low-dose CT images from the Symbia T6 than from the Infinia Hawkeye 4. This phantom-based study gives an indication of potential lesion detection in the clinical context as shown by two commonly used SPECT/CT systems, which may assist the clinician in determining whether further diagnostic imaging is justified. © 2015 by the Society of Nuclear Medicine and Molecular Imaging

  1. Management for BI-RADS category 3 lesions detected in preoperative breast MR imaging of breast cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Gweon, Hye Mi [Seoul National University College of Medicine, Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Gangnam Severance Hospital, Yonsei University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Cho, Nariya; Kim, Soo-Yeon [Seoul National University College of Medicine, Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Koo, Hye Ryoung [Hanyang University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seo, Mirinae [Kyung Hee University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Chu, Ajung [Seoul National University College of Medicine, Boramae Medical Center, Department of Radiology, Seoul (Korea, Republic of); Son, Eun Ju [Gangnam Severance Hospital, Yonsei University College of Medicine, Department of Radiology, Seoul (Korea, Republic of)

    2017-08-15

    To retrospectively evaluate characteristics of and determine appropriate follow-up recommendations for BI-RADS category 3 lesions detected in preoperative MRI of breast cancer patients. BI-RADS category 3 assessments were identified from the breast MRI database for 5,110 consecutive breast cancer patients who had undergone preoperative MRI and surgery. Patient and lesion characteristics, malignancy rate, and interval between lesion detection and cancer diagnosis were analysed. Histopathological results or imaging at or after 2-year follow-up were used as reference standards. Of the 626 lesions, morphological features included a single focus in 26.5% (n = 166), multiple foci in 47.1% (n = 295), mass in 21.7% (n = 136) and non-mass enhancement in 4.6% (n = 29). Cancer was found in 0.8% (5/626) at a median interval of 50 months (range, 29-66 months). Malignancy rate according to morphological feature was: 1.8% (3/166) in a single focus, 0.7% (1/136) in mass and 3.4% (1/29) in non-mass enhancement. All detected cancers were stage 0 or IA. Annual follow-up might be adequate for BI-RADS category 3 lesions detected at preoperative MRI because of the 0.8% (5/626) malignancy rate, long interval between lesion detection and cancer diagnosis, and early stage of diagnosed cancers. (orig.)

  2. Endoscopic detection rate of sessile serrated lesions in Lynch syndrome patients is comparable to an age- and gender-matched control population: case-control study with expert pathology review

    NARCIS (Netherlands)

    Vleugels, Jasper L. A.; Sahin, Husna; Hazewinkel, Yark; Koens, Lianne; van den Berg, Jose G.; van Leerdam, Monique E.; Dekker, Evelien

    2017-01-01

    Carcinogenesis in Lynch syndrome involves fast progression of adenomas to colorectal cancer (CRC) due to microsatellite instability. The role of sessile serrated lesions (SSLs) and the serrated neoplasia pathway in these patients is unknown. The aim of this matched case-control study was to compare

  3. Role of Visual Inspection of Cervix with Acetic Acid (VIA in Detecting Precancerous Lesions of Cervix

    Directory of Open Access Journals (Sweden)

    Kamrun Nessa

    2014-01-01

    Full Text Available Background: Carcinoma of cervix is the most common malignancy in female and a major public health problem worldwide. It is the leading cause of death from cancer among women in low resource settings. In Bangladesh, mortality rate is high as most of the cases with cervical cancer are diagnosed in advanced stage. World Health Organization considers cervical cancer as a preventable disease as it can be identified in preinvasive stage. Considerable efforts have been given in detection and treatment of the condition all over the world. A number of cervical cancer screening tests are available. Among them, visual inspection of cervix with acetic acid is rational and can be competently performed by physicians with proper training. Objective: To find out the feasibility of the visual inspection of cervix with acetic acid for the detection of the precancerous lesions of the cervix in our country. Materials and Methods: This cross sectional, analytical study was carried out among the patients attending the outpatient department of Bangabandhu Sheikh Mujib Medical University (BSMMU who were VIA positive and sent for colposcopy in the colposcopy clinic in the department of Obstetrics and Gynecology in BSMMU from June to December 2004. Two hundred samples were considered for this study. Results: Out of 200 cases, colposcopically 85% had CIN and invasive lesions, 4% had inflammatory lesions while 11% had normal findings. Colposcopy directed punch biopsy revealed positive lesions in 81%, 4% had inflammatory lesions while 15% had normal findings. Conclusion: The study concluded that VIA and colposcopy are the important methods in the evaluation of cervical premalignancy. VIA may be an important tool for screening of cervical cancer in low resource settings as it is simple, easy to perform and cost-effective. After screening, VIA positive cases must be referred for colposcopic evaluation. We can screen cervical cancer by VIA all over the country and thus reduce

  4. An Optimized Clustering Approach for Automated Detection of White Matter Lesions in MRI Brain Images

    Directory of Open Access Journals (Sweden)

    M. Anitha

    2012-04-01

    Full Text Available Settings White Matter lesions (WMLs are small areas of dead cells found in parts of the brain. In general, it is difficult for medical experts to accurately quantify the WMLs due to decreased contrast between White Matter (WM and Grey Matter (GM. The aim of this paper is to
    automatically detect the White Matter Lesions which is present in the brains of elderly people. WML detection process includes the following stages: 1. Image preprocessing, 2. Clustering (Fuzzy c-means clustering, Geostatistical Possibilistic clustering and Geostatistical Fuzzy clustering and 3.Optimization using Particle Swarm Optimization (PSO. The proposed system is tested on a database of 208 MRI images. GFCM yields high sensitivity of 89%, specificity of 94% and overall accuracy of 93% over FCM and GPC. The clustered brain images are then subjected to Particle Swarm Optimization (PSO. The optimized result obtained from GFCM-PSO provides sensitivity of 90%, specificity of 94% and accuracy of 95%. The detection results reveals that GFCM and GFCMPSO better localizes the large regions of lesions and gives less false positive rate when compared to GPC and GPC-PSO which captures the largest loads of WMLs only in the upper ventral horns of the brain.

  5. Brain lesions in congenital nystagmus as detected by computed tomography

    International Nuclear Information System (INIS)

    Lo, Chin-Ying

    1982-01-01

    Computed tomography (CT) was performed in a series of 60 cases with congenital nystagmus. The type of nystagmus was pendular in 20 and jerky in 40 cases. The age ranged from 3 months to 13 years. Abnormal CT findings of the central nervous system were detected in 31 cases (52%). There were 5 major CT findings: midline anomalies, cortical atrophy, ventricular dilatation, brain stem atrophy and low density area. The midline anomalies involved cavum septi pellucidi, cavum Vergae, cavum veli interpositi and partial agenesis of corpus callosum. The abnormal CT findings were more prominent in pendular type than in jerky type. The incidence of congenital nystagmus and positive CT findings were the same in the first and the second birth. There was a history of abnormalities during the prenatal or perinatal period in 28 out of the 60 cases (47%). This feature seemed to play a significant role in the occurrence of congenital nystagmus. The observed organic lesions in the central nervous system by CT would contribute to the elucidation of pathomechanism of congenital nystagmus. (author)

  6. Impact of variations in fatty liver on sonographic detection of focal hepatic lesions originally identified by CT

    International Nuclear Information System (INIS)

    Wu, Size; Tu, Rong; Nan, Ruixia; Liu, Guang Qing; Cui, Xiao Jing; Liang, Xian

    2016-01-01

    The aim of this study was to investigate the influence of variations in fatty liver on the ultrasonographic detection of focal liver lesions. A total of 229 patients with varying degrees of fatty liver and focal liver lesions and 200 patients with focal liver lesions but no fatty liver were randomly selected for inclusion in groups I and II, respectively. Findings of focal liver lesions identified on computed tomography were taken as the reference, and findings on ultrasonography were compared with them. The number of focal liver lesions in groups I and II were 501 and 413, respectively. The ultrasonographic detection rates of focal liver lesions in groups I and II were 86.8% (435/501) and 94.2% (389/413), respectively. Comparison of the detection of the focal lesions between patients with and without fatty liver or different grades of fatty liver were as follows: mild fatty liver (162/177) vs. liver without fat infiltration (389/413) (P=0.277); mild fatty liver (162/177) vs. moderate fatty liver (190/212) (P=0.604); mild fatty liver (162/177) vs. severe fatty liver (83/112) (P<0.001); moderate fatty liver (190/212) vs. liver without fat infiltration (389/413) (P=0.051); moderate fatty liver (190/212) vs. severe fatty liver (83/112) (P<0.001); severe fatty liver (83/112) vs. liver without fat infiltration (389/413) (P<0.001); and fatty liver (435/501) vs. liver without fat infiltration (389/413) (P<0.001). Mild and moderate fatty liver are not significantly associated with the visualization of the lesion, while severe fatty liver usually impairs the detection of focal lesions in the liver. If a patient with severe fatty liver is suspected to have a liver tumor, ultrasonography should only be chosen cautiously in case of a missed diagnosis

  7. Impact of variations in fatty liver on sonographic detection of focal hepatic lesions originally identified by CT

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Size; Tu, Rong; Nan, Ruixia; Liu, Guang Qing; Cui, Xiao Jing; Liang, Xian [Affiliated Hospital of Hainan Medical College, Haikou (China)

    2016-01-15

    The aim of this study was to investigate the influence of variations in fatty liver on the ultrasonographic detection of focal liver lesions. A total of 229 patients with varying degrees of fatty liver and focal liver lesions and 200 patients with focal liver lesions but no fatty liver were randomly selected for inclusion in groups I and II, respectively. Findings of focal liver lesions identified on computed tomography were taken as the reference, and findings on ultrasonography were compared with them. The number of focal liver lesions in groups I and II were 501 and 413, respectively. The ultrasonographic detection rates of focal liver lesions in groups I and II were 86.8% (435/501) and 94.2% (389/413), respectively. Comparison of the detection of the focal lesions between patients with and without fatty liver or different grades of fatty liver were as follows: mild fatty liver (162/177) vs. liver without fat infiltration (389/413) (P=0.277); mild fatty liver (162/177) vs. moderate fatty liver (190/212) (P=0.604); mild fatty liver (162/177) vs. severe fatty liver (83/112) (P<0.001); moderate fatty liver (190/212) vs. liver without fat infiltration (389/413) (P=0.051); moderate fatty liver (190/212) vs. severe fatty liver (83/112) (P<0.001); severe fatty liver (83/112) vs. liver without fat infiltration (389/413) (P<0.001); and fatty liver (435/501) vs. liver without fat infiltration (389/413) (P<0.001). Mild and moderate fatty liver are not significantly associated with the visualization of the lesion, while severe fatty liver usually impairs the detection of focal lesions in the liver. If a patient with severe fatty liver is suspected to have a liver tumor, ultrasonography should only be chosen cautiously in case of a missed diagnosis.

  8. Malignancy rate of biopsied suspicious bone lesions identified on FDG PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Hugo J.A.; Kwee, Thomas C. [University Medical Center Utrecht, Department of Radiology and Nuclear Medicine, Utrecht (Netherlands); Klerk, John M.H. de [Meander Medical Center, Department of Nuclear Medicine, Amersfoort (Netherlands); Heggelman, Ben G.F. [Meander Medical Center, Department of Radiology, Amersfoort (Netherlands); Dubois, Stefan V. [Meander Medical Center, Department of Pathology, Amersfoort (Netherlands)

    2016-07-15

    To determine the malignancy rate of bone lesions identified on FDG PET/CT in patients who have undergone CT-guided biopsy because of the suspicion of malignancy. This single-centre retrospective study spanned eight consecutive years and included all patients who underwent both FDG PET/CT and CT-guided bone biopsy because of the suspicion of malignancy. The positive predictive value (PPV) for malignancy was calculated, and different patient and imaging characteristics were compared between malignant and benign bone lesions. Of 102 included patients with bone lesions that all showed FDG uptake exceeding mediastinal uptake, bone biopsy showed a malignant lesion in 91 patients, yielding a PPV for malignancy of 89.2 % (95 % CI 81.7 - 93.9 %). In the 94 patients with bone lesions that showed FDG uptake exceeding liver uptake, bone biopsy showed a malignant lesion in 83 patients, yielding a PPV for malignancy of 88.3 % (95 % CI 80.1 - 93.5 %). Higher age, bone marrow replacement of the lesion seen on CT, expansion of the lesion seen on CT, and presence of multifocal lesions on FDG PET/CT were significantly more frequent in patients with malignant lesions than in those with benign bone lesions (P = 0.044, P = 0.009, P = 0.015, and P = 0.019, respectively). Furthermore, there was a trend towards a higher incidence of cortical destruction (P = 0.056) and surrounding soft tissue mass (P = 0.063) in patients with malignant bone lesions. The PPV for malignancy of suspicious bone lesions identified on FDG PET/CT is not sufficiently high to justify changes in patient management without histopathological confirmation. Nevertheless, ancillary patient and imaging characteristics may increase the likelihood of a malignant bone lesion. (orig.)

  9. Characteristics, Detection Methods and Treatment of Questionable Occlusal Carious Lesions

    DEFF Research Database (Denmark)

    Makhija, S.K.; Gilbert, G.H.; Funkhouser, E.

    2014-01-01

    . The objective of this report has been to quantify the characteristics of these common lesions, the diagnostic aids used and the treatment of QOC. A total of 82 dentist and hygienist practitioner-investigators from the USA and Denmark in the National Dental Practice-Based Research Network participated. When...... consenting patients presented with a QOC, information was recorded about the patient, tooth, lesion and treatments. A total of 2,603 QOC from 1,732 patients were analyzed. The lesions were usually associated with a fissure, on molars, and varied from yellow to black in color. Half presented with a chalky...... luster and had a rough surface when examined with an explorer. There was an association between color and luster: 10% were chalky-light, 47% were shiny-dark and 42% were mixtures. A higher proportion of chalky than of shiny lesions were light (22 vs. 9%; p color were less common...

  10. Evaluation of the Significance of Incidental Breast Lesions Detected by Chest CT

    International Nuclear Information System (INIS)

    Kim, Jae Hyun; Chang, Yun Woo; Hwang, Jung Hwa; Kim, Hyung Hwan; Lee, Eun Hye; Yang, Seung Boo

    2013-01-01

    To evaluate the significance of incidentally detected breast lesions on a chest CT scan. Thirty-six incidental breast lesions in 26 patients were detected on a chest CT scan and were correlated with breast sonography, retrospectively. Among them, twenty-four breast lesions in 20 patients that were correlated with chest CT and sonography were available to pathology or follow up sonography. The CT findings were compared with sonographic findings according to the pathologic results. Incidentally detected breast lesions on a chest CT scan were correlated with sonography in 86% (31/36). Among 24 lesions that were available to pathology or follow up sonography, seven (29.2%) lesions were malignant and 17 (70.8%) lesions were benign. CT revealed a significant difference between benign and malignant lesions in terms of shape and margin (p = 0.007; p = 0.008, respectively). The CT findings were well correlated with sonographic findings in shape and margin (p = 0.001, respectively). Incidentally detected breast lesions on chest CT can be correlated with sonography. An irregular shape or a non-circumscribed margin of breast lesions on a CT scan can be considered as a suggestive sign of malignancy.

  11. Contralateral lesions detected by preoperative MRI in patients with recently diagnosed breast cancer: Application of MR CAD in differentiation of benign and malignant lesions

    International Nuclear Information System (INIS)

    Cho, Nariya; Kim, Sun Mi; Park, Jeong Seon; Jang, Mijung; Kim, Soo-Yeon; Chang, Jung Min; Moon, Woo Kyung

    2012-01-01

    Objectives: To retrospectively investigate the added value of kinetic features measured by computer-aided diagnosis (CAD) for differentiating benign and malignant contralateral breast lesions detected by preoperative MRI in breast cancer patients. Methods: This study was approved by our institutional review board, and the requirement for informed consent was waived. Fifty-two breast MR images and their CAD kinetic features were obtained for 52 consecutive breast cancer patients with contralateral breast lesions detected by preoperative MRI and confirmed by excision (23 cancers and 29 benign lesions). Three experienced radiologists independently reviewed the MR images without CAD information and assessed probabilities of malignancy. Four weeks later, these probabilities were reanalyzed using stored CAD data. Diagnostic performances and detection rates of delayed washout components were compared between interpretations without and with CAD for each reader. Results: Use of MR CAD increased detection of washout component by 2.4- to 3.7-fold than visual assessment for enhancing contralateral lesions, which increased sensitivity (91% vs. 87% in reader 1; 96% vs. 74% in reader 2; 91% vs. 70% in reader 3) and decreased specificity, but statistical significance was only found for decreased specificity in one reader (52% vs. 28%, P = 0.039), and overall performance (areas under ROC curves 0.672 vs. 0.616 in reader 1; 0.624 vs. 0.603 in reader 2; 0.706 vs. 0.590 in reader 3) remained unimproved. Conclusion: Addition of MR CAD increased sensitivity and decreased specificity than radiologist's assessment alone for differentiating benign and malignant contralateral lesions in breast cancer patients and overall performance remained unimproved.

  12. An ensemble deep learning based approach for red lesion detection in fundus images.

    Science.gov (United States)

    Orlando, José Ignacio; Prokofyeva, Elena; Del Fresno, Mariana; Blaschko, Matthew B

    2018-01-01

    Diabetic retinopathy (DR) is one of the leading causes of preventable blindness in the world. Its earliest sign are red lesions, a general term that groups both microaneurysms (MAs) and hemorrhages (HEs). In daily clinical practice, these lesions are manually detected by physicians using fundus photographs. However, this task is tedious and time consuming, and requires an intensive effort due to the small size of the lesions and their lack of contrast. Computer-assisted diagnosis of DR based on red lesion detection is being actively explored due to its improvement effects both in clinicians consistency and accuracy. Moreover, it provides comprehensive feedback that is easy to assess by the physicians. Several methods for detecting red lesions have been proposed in the literature, most of them based on characterizing lesion candidates using hand crafted features, and classifying them into true or false positive detections. Deep learning based approaches, by contrast, are scarce in this domain due to the high expense of annotating the lesions manually. In this paper we propose a novel method for red lesion detection based on combining both deep learned and domain knowledge. Features learned by a convolutional neural network (CNN) are augmented by incorporating hand crafted features. Such ensemble vector of descriptors is used afterwards to identify true lesion candidates using a Random Forest classifier. We empirically observed that combining both sources of information significantly improve results with respect to using each approach separately. Furthermore, our method reported the highest performance on a per-lesion basis on DIARETDB1 and e-ophtha, and for screening and need for referral on MESSIDOR compared to a second human expert. Results highlight the fact that integrating manually engineered approaches with deep learned features is relevant to improve results when the networks are trained from lesion-level annotated data. An open source implementation of our

  13. Effectiveness of core biopsy for screen-detected breast lesions under 10 mm: implications for surgical management.

    Science.gov (United States)

    Farshid, Gelareh; Downey, Peter; Pieterse, Steve; Gill, P Grantley

    2017-09-01

    Technical advances have improved the detection of small mammographic lesions. In the context of mammographic screening, accurate sampling of these lesions by percutaneous biopsy is crucial in limiting diagnostic surgical biopsies, many of which show benign results. Women undergoing core biopsy between January 1997 and December 2007 for core histology, 345 women (43.0%) were immediately cleared of malignancy and 300 (37.4%) were referred for definitive cancer treatment. A further 157 women (19.6%) required diagnostic surgical biopsy because of indefinite or inadequate core results or radiological-pathological discordance, and one woman (0.1%) needed further imaging in 12 months. The open biopsies were malignant in 46 (29.3%) cases. The positive predictive value of malignant core biopsy was 100%. The negative predictive value for benign core results was 97.7%, and the false-negative rate was 2.6%. The lesion could not be visualized after core biopsy in 5.1% of women and in 4.0% of women with malignant core biopsies excision specimens did not contain residual malignancy. Excessive delays in surgery because of complications of core biopsy were not reported. Even at this small size range, core biopsy evaluation of screen-detected breast lesions is highly effective and accurate. A lesion miss rate of 3.1% and under-representation of lesions on core samples highlight the continued need for multidisciplinary collaboration and selective use of diagnostic surgical biopsy. © 2015 Royal Australasian College of Surgeons.

  14. Comparison of AMI-25 enhanced MRI and helical dynamic CT in the detection of hepatic lesions

    International Nuclear Information System (INIS)

    Saitou, Kazuhiro; Matsuda, Hiromichi; Fukushima, Hiroaki; Kanzaki, Hiroshi; Hirose, Takashi; Karizaki, Dai; Abe, Kimihiko; Amino, Saburou

    1994-01-01

    We performed AMI-25 enhanced MRI and helical dynamic CT in 12 cases of hepatic lesions. Nine of these were hepatocellular carcinomas. Two cases were metastatic liver tumors (the primary lesion was gastric in one and the other was gallbladder cancer). One case was suspected to be adenomatous hyperplasia. Thirty-two lesions were detected in T2-weighted SE images before AMI-25 administration, while 46 lesions were detected in AMI-25 enhanced MRI images. In particular, AMI-25 enhanced MRI was superior to plain MRI in lesions less than 10 mm in size. A total of 48 lesions were detected in helical dynamic CT. Although AMI-25 enhanced MRI almost equaled helical dynamic CT in the detection of liver tumors, helical dynamic CT was slightly superior to AMI-25 enhanced MRI in the detection of subphrenic lesions. It was possible to know the hemodynamics in each hepatic lesion by helical dynamic CT. AMI-25 enhanced MRI was useful to know the inclusion of reticuloendothelial system, and that yielded different diagnoses in adenomatous hyperplasia and well differentiated hepatocellular carcinoma. Helical dynamic CT was useful for qualitative diagnosis. Both AMI-25 enhanced MRI and helical dynamic CT contributed to the detection of liver tumor and qualitative diagnosis. (author)

  15. Detection of flat colorectal polyps at screening CT colonography in comparison with conventional polypoid lesions

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Takashi; Urata, Joji [Diagnostic Imaging Center, Saiseikai Kumamoto Hospital, Kumamoto (Japan); Mitsuzaki, Katsuhiko; Matsuda, Katsuhiko; Kawakami, Megumi [Medical Examination Center, Saiseikai Kumamoto Hospital, Kumamoto (Japan); Utsunomiya, Daisuke; Yamamura, Sadahiro; Yamashita, Yasuyuki [Diagnostic Radiology, Faculty of Life Sciences, Kumamoto Univ., Kumamoto (Japan)], e-mail: utsunomi@kumamoto-u.ac.jp

    2012-09-15

    Background: Although the screening of small, flat polyps is clinically important, the role of CT colonography (CTC) screening in their detection has not been thoroughly investigated. Purpose: To evaluate the detection capability and usefulness of CTC in the screening of flat and polypoid lesions by comparing CTC with optic colonoscopy findings as the gold standard. Material and Methods: We evaluated the CTC detection capability for flat colorectal polyps with a flat surface and a height not exceeding 3 mm (n = 42) by comparing to conventional polypoid lesions (n = 418) according to the polyp diameter. Four types of reconstruction images including multiplanar reconstruction, volume rendering, virtual gross pathology, and virtual endoscopic images were used for visual analysis. We compared the abilities of the four reconstructions for polyp visualization. Results: Detection sensitivity for flat polyps was 31.3 %, 44.4 %, and 87.5 % for lesions measuring 2-3 mm, 4-5 mm, and {>=}6 mm, respectively; the corresponding sensitivity for polypoid lesions was 47.6 %, 79.0 %, and 91.7 %. The overall sensitivity for flat lesions (47.6%) was significantly lower than polypoid lesions (64.1%). Virtual endoscopic imaging showed best visualization among the four reconstructions. Colon cancers were detected in eight patients by optic colonoscopy, and CTC detected colon cancers in all eight patients. Conclusion: CTC using 64-row multidetector CT is useful for colon cancer screening to detect colorectal polyps while the detection of small, flat lesions is still challenging.

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

    Science.gov (United States)

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

    2017-05-01

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

  17. Improved assessment of multiple sclerosis lesion segmentation agreement via detection and outline error estimates

    Directory of Open Access Journals (Sweden)

    Wack David S

    2012-07-01

    Full Text Available Abstract Background Presented is the method “Detection and Outline Error Estimates” (DOEE for assessing rater agreement in the delineation of multiple sclerosis (MS lesions. The DOEE method divides operator or rater assessment into two parts: 1 Detection Error (DE -- rater agreement in detecting the same regions to mark, and 2 Outline Error (OE -- agreement of the raters in outlining of the same lesion. Methods DE, OE and Similarity Index (SI values were calculated for two raters tested on a set of 17 fluid-attenuated inversion-recovery (FLAIR images of patients with MS. DE, OE, and SI values were tested for dependence with mean total area (MTA of the raters' Region of Interests (ROIs. Results When correlated with MTA, neither DE (ρ = .056, p=.83 nor the ratio of OE to MTA (ρ = .23, p=.37, referred to as Outline Error Rate (OER, exhibited significant correlation. In contrast, SI is found to be strongly correlated with MTA (ρ = .75, p  Conclusions The DE and OER indices are proposed as a better method than SI for comparing rater agreement of ROIs, which also provide specific information for raters to improve their agreement.

  18. Experimental phantom lesion detectability study using a digital breast tomosynthesis prototype system

    International Nuclear Information System (INIS)

    Schulz-Wendtland, R.; Wenkel, E.; Lell, M.; Boehner, C.; Bautz, W.A.; Mertelmeier, T.

    2006-01-01

    Purpose: To compare the sensitivity of conventional two-dimensional (2D) projection imaging with tomosynthesis with respect to the detectability of mammographic phantom lesions. Materials and Methods: Using a breast tomosynthesis prototype based on a commercial FFDM system (Siemens MAMMOMAT Novation DR ), but modified for a wide angle tube motion and equipped with a fast read-out amorphous selenium detector, we acquired standard 2D images and tomosynthesis series of projection views. We used the Wisconsin mammographic random phantom, model RMI 152A. The anode filter combinations Mo/Mo and W/Rh at two different doses were used as typical radiographic techniques. Slice images through the phantom parallel to the detector were reconstructed with a distance of 1 mm employing a filtered back-projection algorithm. The image data sets were read by five radiologists and evaluated with respect to the detectability of the phantom details. Results: For all studied radiographic techniques, the detection rate in the tomosynthesis mode was 100%, i.e. 75 true positive findings out of 75 possible hits. In contrast, the conventional projection mode yielded a detection rate between 80 and 93% (corresponding to 60 and 70 detected details) depending on the dose and X-ray spectrum. Conclusion: Tomosynthesis has the potential to increase the sensitivity of digital mammography. Overlapping structures from out-of-plane tissue can be removed in the tomosynthesis reconstruction process, thereby enhancing the diagnostic accuracy. (orig.)

  19. A Robust and Fast System for CTC Computer-Aided Detection of Colorectal Lesions

    Directory of Open Access Journals (Sweden)

    Gareth Beddoe

    2010-01-01

    Full Text Available We present a complete, end-to-end computer-aided detection (CAD system for identifying lesions in the colon, imaged with computed tomography (CT. This system includes facilities for colon segmentation, candidate generation, feature analysis, and classification. The algorithms have been designed to offer robust performance to variation in image data and patient preparation. By utilizing efficient 2D and 3D processing, software optimizations, multi-threading, feature selection, and an optimized cascade classifier, the CAD system quickly determines a set of detection marks. The colon CAD system has been validated on the largest set of data to date, and demonstrates excellent performance, in terms of its high sensitivity, low false positive rate, and computational efficiency.

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

    Science.gov (United States)

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

    2018-03-01

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

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

    Science.gov (United States)

    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.

  2. Detection of rotator cuff lesions with indirect MR angiography

    International Nuclear Information System (INIS)

    Rudolph, J.; Lorenz, M.; Schroeder, R.; Felix, R.

    2000-01-01

    Purpose: To determine the value of indirect MR arthrography in lesions of the rotator cuff, prospectively versus arthroscopy. Methods: 63 patients with suspected shoulder pathology were examined: Oblique-coronary and axial T 1 w sequences, axial FLASH-2 D sequences, furthermore oblique-coronary T 2 - and PD-weighted sequences were taken. After intravenous administration of 0.1 mmol Gd-DTPA/kilogram body weight and active motion of the shoulder T 1 w sequences were repeated. Signal intensities (SI) inside the tendon were quantitatively measured by the ROI technique (region-of-interest) and the percentual contrast-enhancement CE was calculated. In 32 patients the results were confirmed by surgical follow-up. Results: The mean SI measured in the supraspinous tendon were higher in lesions (degeneration, impingement, partial and total rupture), before as well as after contrast medium, compared to intact findings (p [de

  3. Going With the Flow: An Aid in Detecting and Differentiating Bronchopulmonary Sequestrations and Hybrid Lesions.

    Science.gov (United States)

    Oliver, Edward R; DeBari, Suzanne E; Giannone, Mariann M; Pogoriler, Jennifer E; Johnson, Ann M; Horii, Steven C; Gebb, Juliana S; Howell, Lori J; Adzick, N Scott; Coleman, Beverly G

    2018-02-01

    68 of 73 hybrid lesions. Ultrasound is most accurate for systemic feeding artery detection in bronchopulmonary sequestrations and hybrid lesions and can also type the lesions as intralobar or extralobar when draining veins are evaluated. © 2017 by the American Institute of Ultrasound in Medicine.

  4. A Novel Fuzzy Topological Approach to the Detection of Mammographic Lesions and Quantification of Parenchymal Density

    National Research Council Canada - National Science Library

    Udupa, Jayaram

    2001-01-01

    .... During this project period, the following have been accomplished: The development and validation of a new method of lesion and density detection based on fuzzy connectedness that utilizes the relative strength of connectedness among objects...

  5. Automated multi-lesion detection for referable diabetic retinopathy in indigenous health care.

    Science.gov (United States)

    Pires, Ramon; Carvalho, Tiago; Spurling, Geoffrey; Goldenstein, Siome; Wainer, Jacques; Luckie, Alan; Jelinek, Herbert F; Rocha, Anderson

    2015-01-01

    Diabetic Retinopathy (DR) is a complication of diabetes mellitus that affects more than one-quarter of the population with diabetes, and can lead to blindness if not discovered in time. An automated screening enables the identification of patients who need further medical attention. This study aimed to classify retinal images of Aboriginal and Torres Strait Islander peoples utilizing an automated computer-based multi-lesion eye screening program for diabetic retinopathy. The multi-lesion classifier was trained on 1,014 images from the São Paulo Eye Hospital and tested on retinal images containing no DR-related lesion, single lesions, or multiple types of lesions from the Inala Aboriginal and Torres Strait Islander health care centre. The automated multi-lesion classifier has the potential to enhance the efficiency of clinical practice delivering diabetic retinopathy screening. Our program does not necessitate image samples for training from any specific ethnic group or population being assessed and is independent of image pre- or post-processing to identify retinal lesions. In this Aboriginal and Torres Strait Islander population, the program achieved 100% sensitivity and 88.9% specificity in identifying bright lesions, while detection of red lesions achieved a sensitivity of 67% and specificity of 95%. When both bright and red lesions were present, 100% sensitivity with 88.9% specificity was obtained. All results obtained with this automated screening program meet WHO standards for diabetic retinopathy screening.

  6. Automated multi-lesion detection for referable diabetic retinopathy in indigenous health care.

    Directory of Open Access Journals (Sweden)

    Ramon Pires

    Full Text Available Diabetic Retinopathy (DR is a complication of diabetes mellitus that affects more than one-quarter of the population with diabetes, and can lead to blindness if not discovered in time. An automated screening enables the identification of patients who need further medical attention. This study aimed to classify retinal images of Aboriginal and Torres Strait Islander peoples utilizing an automated computer-based multi-lesion eye screening program for diabetic retinopathy. The multi-lesion classifier was trained on 1,014 images from the São Paulo Eye Hospital and tested on retinal images containing no DR-related lesion, single lesions, or multiple types of lesions from the Inala Aboriginal and Torres Strait Islander health care centre. The automated multi-lesion classifier has the potential to enhance the efficiency of clinical practice delivering diabetic retinopathy screening. Our program does not necessitate image samples for training from any specific ethnic group or population being assessed and is independent of image pre- or post-processing to identify retinal lesions. In this Aboriginal and Torres Strait Islander population, the program achieved 100% sensitivity and 88.9% specificity in identifying bright lesions, while detection of red lesions achieved a sensitivity of 67% and specificity of 95%. When both bright and red lesions were present, 100% sensitivity with 88.9% specificity was obtained. All results obtained with this automated screening program meet WHO standards for diabetic retinopathy screening.

  7. Linked color imaging reduces the miss rate of neoplastic lesions in the right colon: a randomized tandem colonoscopy study.

    Science.gov (United States)

    Paggi, Silvia; Mogavero, Giuseppe; Amato, Arnaldo; Rondonotti, Emanuele; Andrealli, Alida; Imperiali, Gianni; Lenoci, Nicoletta; Mandelli, Giovanna; Terreni, Natalia; Conforti, Francesco Simone; Conte, Dario; Spinzi, Giancarlo; Radaelli, Franco

    2018-04-01

     Linked color imaging (LCI) is a newly developed image-enhancing endoscopy technology that provides bright endoscopic images and increases color contrast. We investigated whether LCI improves the detection of neoplastic lesions in the right colon when compared with high definition white-light imaging (WLI).  Consecutive patients undergoing colonoscopy were randomized (1:1) after cecal intubation into right colon inspection at first pass by LCI or by WLI. At the hepatic flexure, the scope was reintroduced to the cecum under LCI and a second right colon inspection was performed under WLI in previously LCI-scoped patients (LCI-WLI group) and vice versa (WLI-LCI group). Lesions detected on first- and second-pass examinations were used to calculate detection and miss rates, respectively. The primary outcome was the right colon adenoma miss rate.  Of the 600 patients enrolled, 142 had at least one adenoma in the right colon, with similar right colon adenoma detection rates (r-ADR) in the two groups (22.7 % in LCI-WLI and 24.7 % in WLI-LCI). At per-polyp analysis, double inspection of the right colon in the LCI-WLI and WLI-LCI groups resulted in an 11.8 % and 30.6 % adenoma miss rate, respectively ( P  one adenoma was identified in the second pass only (incremental ADR) in 2 of 300 patients (0.7 %) in the LCI - WLI group and in 13 of 300 patients (4.3 %) in the WLI - LCI group ( P  = 0.01).  LCI could reduce the miss rate of neoplastic lesions in the right colon. © Georg Thieme Verlag KG Stuttgart · New York.

  8. DETECTION OF CANCEROUS LESION BY UTERINE CERVIX IMAGE SEGMENTATION

    Directory of Open Access Journals (Sweden)

    P. Priya

    2014-02-01

    Full Text Available This paper works at segmentation of lesion observed in cervical cancer, which is the second most common cancer among women worldwide. The purpose of segmentation is to determine the location for a biopsy to be taken for diagnosis. Cervix cancer is a disease in which cancer cells are found in the tissues of the cervix. The acetowhite region is a major indicator of abnormality in the cervix image. This project addresses the problem of segmenting uterine cervix image into different regions. We analyze two algorithms namely Watershed, K-means clustering algorithm, Expectation Maximization (EM Image Segmentation algorithm. These segmentations methods are carried over for the colposcopic uterine cervix image.

  9. Comparisons of lesion detectability in ultrasound images acquired using time-shift compensation and spatial compounding.

    Science.gov (United States)

    Lacefield, James C; Pilkington, Wayne C; Waag, Robert C

    2004-12-01

    The effects of aberration, time-shift compensation, and spatial compounding on the discrimination of positive-contrast lesions in ultrasound b-scan images are investigated using a two-dimensional (2-D) array system and tissue-mimicking phantoms. Images were acquired within an 8.8 x 12-mm2 field of view centered on one of four statistically similar 4-mm diameter spherical lesions. Each lesion was imaged in four planes offset by successive 45 degree rotations about the central scan line. Images of the lesions were acquired using conventional geometric focusing through a water path, geometric focusing through a 35-mm thick distributed aberration phantom, and time-shift compensated transmit and receive focusing through the aberration phantom. The views of each lesion were averaged to form sets of water path, aberrated, and time-shift compensated 4:1 compound images and 16:1 compound images. The contrast ratio and detectability index of each image were computed to assess lesion differentiation. In the presence of aberration representative of breast or abdominal wall tissue, time-shift compensation provided statistically significant improvements of contrast ratio but did not consistently affect the detectability index, and spatial compounding significantly increased the detectability index but did not alter the contrast ratio. Time-shift compensation and spatial compounding thus provide complementary benefits to lesion detection.

  10. A comparison between fast and conventional spin-echo in the detection of multiple sclerosis lesions

    International Nuclear Information System (INIS)

    Thorpe, J.W.; Halpin, S.F.; MacManus, D.G.; Barker, G.J.; Kendall, B.E.; Miller, D.H.

    1994-01-01

    Long repetition time (TR) spin-echo (SE) with T 2 - or proton density weighting is the sequence of choice to detect the brain lesions of multiple sclerosis (MS). Fast spin-echo (FSE) permits the generation of T 2 -weighted images with similar contrast to SE but in a fraction of the time. We compared the sensitivity of FSE and SE in the detection of the brain lesions of MS. Six patients with clinically definite MS underwent brain imaging with both dual echo (long TR, long and short echo time (TE) SE and dual echo FSE. The SE and FSE images were first reviewed independently and then compared. A total of 404 lesions was detected on SE and 398 on FSE. Slightly more periventricular lesions were detected using SE than FSE (145 vs 127), whereas more posterior cranial fossa lesions were detected by FSE (77 vs 57). With both SE and FSE the short TE images revealed more lesions than the long echo. These results suggest that FSE could replace SE as the long TR sequence of choice in the investigation of MS. (orig.)

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

    Science.gov (United States)

    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.

  12. Differentiation of thyroid lesion detected by FDG PET/CT using SUV ratio

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bom Sahn; Kang, Won Jun; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    We investigated the usefulness of SUV ratio to discriminate focal thyroid lesion incidentally detected on 18F-FDG PET/CT (FDG PET) in patients with malignant disease. A total of 2167 subjects with malignant tumor underwent PET/CT for staging. Forty-five of 2167 subjects (2.1%) showed hypermetabolic thyroid lesions on FDG PET. Of 45, 21 lesions were confirmed by pathology (n = 16) or follow up exam (n=5). Seventeen patients had focal FDG uptakes, while 4 patients had diffuse thyroid uptakes. Standardized uptake value (SUV) was measured by drawing region of interest (ROI) on bilateral thyroid lobes and liver. From 21 patients, 12 thyroid lesions were confirmed as malignant lesions and 9 lesions as benign lesions. All of bilateral thyroid FDG uptakes were determined as benign disease such as thyroiditis. From seventeen focal thyroid incidentaloma, FDG PET had 100 % (12/12) of sensitivity and 60 % (3/5) of specificity, retrospectively. Malignant nodules had a significantly higher lesion to liver ratio than those of benign nodules (2.10.9 vs. 1.20.6, p=0.029). With ROC curve, the best cut-off value of lesion to liver was 1.0 with sensitivity of 100% and specificity of 60 % (area under the curve=0.783). The SUV ratio of lesion to contralateral lobe do not have statistical significance to determine malignancy (3.72.1 vs. 2.61.7, p=0.079). This study showed that focal thyroidal FDG uptake detected by FDG PET could be differentiated with best performance by SUV ratio of lesion to liver.

  13. Study of detection probability from lesion by scintiscanning

    International Nuclear Information System (INIS)

    Silva, D.C. da; Dias-Neto, A.L.

    1992-01-01

    The importance of work with the information density parameter in scintiscanning is described, fixing the minimum values of information density, above of which the existent injuries are not detected, allowing also the reproducibility of the examination. (C.G.C.)

  14. Impact of variations in fatty liver on sonographic detection of focal hepatic lesions originally identified by CT

    Directory of Open Access Journals (Sweden)

    Size Wu

    2016-01-01

    Full Text Available Purpose: The aim of this study was to investigate the influence of variations in fatty liver on the ultrasonographic detection of focal liver lesions. Methods: A total of 229 patients with varying degrees of fatty liver and focal liver lesions and 200 patients with focal liver lesions but no fatty liver were randomly selected for inclusion in groups I and II, respectively. Findings of focal liver lesions identified on computed tomography were taken as the reference, and findings on ultrasonography were compared with them. Results: The number of focal liver lesions in groups I and II were 501 and 413, respectively. The ultrasonographic detection rates of focal liver lesions in groups I and II were 86.8% (435/501 and 94.2% (389/413, respectively. Comparison of the detection of the focal lesions between patients with and without fatty liver or different grades of fatty liver were as follows: mild fatty liver (162/177 vs. liver without fat infiltration (389/413 (P=0.277; mild fatty liver (162/177 vs. moderate fatty liver (190/212 (P=0.604; mild fatty liver (162/177 vs. severe fatty liver (83/112 (P<0.001; moderate fatty liver (190/212 vs. liver without fat infiltration (389/413 (P=0.051; moderate fatty liver (190/212 vs. severe fatty liver (83/112 (P<0.001; severe fatty liver (83/112 vs. liver without fat infiltration (389/413 (P<0.001; and fatty liver (435/501 vs. liver without fat infiltration (389/413 (P<0.001. Conclusion: Mild and moderate fatty liver are not significantly associated with the visualization of the lesion, while severe fatty liver usually impairs the detection of focal lesions in the liver. If a patient with severe fatty liver is suspected to have a liver tumor, ultrasonography should only be chosen cautiously in case of a missed diagnosis.

  15. Automated lesion detection on MRI scans using combined unsupervised and supervised methods

    International Nuclear Information System (INIS)

    Guo, Dazhou; Fridriksson, Julius; Fillmore, Paul; Rorden, Christopher; Yu, Hongkai; Zheng, Kang; Wang, Song

    2015-01-01

    Accurate and precise detection of brain lesions on MR images (MRI) is paramount for accurately relating lesion location to impaired behavior. In this paper, we present a novel method to automatically detect brain lesions from a T1-weighted 3D MRI. The proposed method combines the advantages of both unsupervised and supervised methods. First, unsupervised methods perform a unified segmentation normalization to warp images from the native space into a standard space and to generate probability maps for different tissue types, e.g., gray matter, white matter and fluid. This allows us to construct an initial lesion probability map by comparing the normalized MRI to healthy control subjects. Then, we perform non-rigid and reversible atlas-based registration to refine the probability maps of gray matter, white matter, external CSF, ventricle, and lesions. These probability maps are combined with the normalized MRI to construct three types of features, with which we use supervised methods to train three support vector machine (SVM) classifiers for a combined classifier. Finally, the combined classifier is used to accomplish lesion detection. We tested this method using T1-weighted MRIs from 60 in-house stroke patients. Using leave-one-out cross validation, the proposed method can achieve an average Dice coefficient of 73.1 % when compared to lesion maps hand-delineated by trained neurologists. Furthermore, we tested the proposed method on the T1-weighted MRIs in the MICCAI BRATS 2012 dataset. The proposed method can achieve an average Dice coefficient of 66.5 % in comparison to the expert annotated tumor maps provided in MICCAI BRATS 2012 dataset. In addition, on these two test datasets, the proposed method shows competitive performance to three state-of-the-art methods, including Stamatakis et al., Seghier et al., and Sanjuan et al. In this paper, we introduced a novel automated procedure for lesion detection from T1-weighted MRIs by combining both an unsupervised and a

  16. An improved strategy for skin lesion detection and classification using uniform segmentation and feature selection based approach.

    Science.gov (United States)

    Nasir, Muhammad; Attique Khan, Muhammad; Sharif, Muhammad; Lali, Ikram Ullah; Saba, Tanzila; Iqbal, Tassawar

    2018-02-21

    Melanoma is the deadliest type of skin cancer with highest mortality rate. However, the annihilation in early stage implies a high survival rate therefore, it demands early diagnosis. The accustomed diagnosis methods are costly and cumbersome due to the involvement of experienced experts as well as the requirements for highly equipped environment. The recent advancements in computerized solutions for these diagnoses are highly promising with improved accuracy and efficiency. In this article, we proposed a method for the classification of melanoma and benign skin lesions. Our approach integrates preprocessing, lesion segmentation, features extraction, features selection, and classification. Preprocessing is executed in the context of hair removal by DullRazor, whereas lesion texture and color information are utilized to enhance the lesion contrast. In lesion segmentation, a hybrid technique has been implemented and results are fused using additive law of probability. Serial based method is applied subsequently that extracts and fuses the traits such as color, texture, and HOG (shape). The fused features are selected afterwards by implementing a novel Boltzman Entropy method. Finally, the selected features are classified by Support Vector Machine. The proposed method is evaluated on publically available data set PH2. Our approach has provided promising results of sensitivity 97.7%, specificity 96.7%, accuracy 97.5%, and F-score 97.5%, which are significantly better than the results of existing methods available on the same data set. The proposed method detects and classifies melanoma significantly good as compared to existing methods. © 2018 Wiley Periodicals, Inc.

  17. A comparative study of the detectability of TMJ radiographic techniques for artificial mandibular condylar lesions

    International Nuclear Information System (INIS)

    Jeong, Hee Jeong; Jung, Yeon Hwa; Cho, Bong Hae

    1997-01-01

    The purpose of this study was to evaluate the detectability of various radiographic techniques for mandibular condylar lesions. Erosive lesion, osteophyte and flattening were formed on the artificial mandibular condyle, and panoramic, transcranial, transorbital radiography, lateral and frontal tomography were taken. The results were as follows; 1. The detectability for erosive lesions was superior in the order of frontal tomography (96%), lateral tomography (78%), transorbital (59%), transcranial (56%) and panoramic (48%) radiography. 2. The location of erosive lesion that showed the highest detectability was the medial third in panoramic, the lateral third in transcranial, the central portion of anteroposterior direction in transorbital, the central portion of mediolateral direction and the posterior third in lateral tomography. Frontal tomography disclosed all erosive lesions except one anterolateral lesion. 3. The detectability of osteophyte was 100% in lateral tomography, 78% in transcranial and 56% in panoramic radiography. 4. For flattening, lateral tomography showed the flattened condyle, but both panoramic and transcranial views showed only decreased bone density without the change of condylar shape.

  18. Computed tomography-guided percutaneous biopsy of bone lesions: rate of diagnostic success and complications

    International Nuclear Information System (INIS)

    Maciel, Macello Jose Sampaio; Tyng, Chiang Jeng; Barbosa, Paula Nicole Vieira Pinto; Bitencourt, Almir Galvao Vieira; Matushita Junior, Joao Paulo Kawaoka; Zurstrassen, Charles Edouard; Chung, Wu Tu; Chojniak, Rubens

    2014-01-01

    Objective: To determine the rates of diagnostic success and complications of computed tomography (CT)-guided percutaneous biopsy of bone lesions suspected for malignancy. Materials and Methods: Retrospective study including 186 cases of CT-guided percutaneous biopsies of bone lesions in the period from January, 2010 to December, 2012. All the specimens were obtained with 8-10 gauge needles. The following data were collected: demographics, previous history of malignancy, data related to the lesion, to the procedure, and to histological results. Results: Most patients were women (57%), and the mean age was 53.0 ± 16.4 years. In 139 cases (74.6%), there was diagnostic suspicion of metastasis and the most common primary tumors were breast (32.1%) and prostate (11.8%). The bones most commonly involved were spine (36.0%), hip (32.8%) and long bones (18.3%). Complications occurred in only three cases (1.6%) including bone fracture, paraesthesia with functional impairment, and needle breakage requiring surgical removal. The specimens collected from 183 lesions (98.4%) were considered appropriate for diagnosis. Malignant results were more frequently found in patients who had a suspected secondary lesion and history of known malignancy (p < 0.001), and in patients who underwent PET/CT-guided procedures (p = 0.011). Conclusion: CT-guided percutaneous biopsy is a safe and effective procedure for the diagnosis of suspicious bone lesions. (author)

  19. Computed tomography-guided percutaneous biopsy of bone lesions: rate of diagnostic success and complications

    Energy Technology Data Exchange (ETDEWEB)

    Maciel, Macello Jose Sampaio; Tyng, Chiang Jeng; Barbosa, Paula Nicole Vieira Pinto; Bitencourt, Almir Galvao Vieira; Matushita Junior, Joao Paulo Kawaoka; Zurstrassen, Charles Edouard; Chung, Wu Tu; Chojniak, Rubens, E-mail: macellomaciel@me.com [A.C.Camargo Cancer Center, Sao Paulo, SP (Brazil)

    2014-09-15

    Objective: To determine the rates of diagnostic success and complications of computed tomography (CT)-guided percutaneous biopsy of bone lesions suspected for malignancy. Materials and Methods: Retrospective study including 186 cases of CT-guided percutaneous biopsies of bone lesions in the period from January, 2010 to December, 2012. All the specimens were obtained with 8-10 gauge needles. The following data were collected: demographics, previous history of malignancy, data related to the lesion, to the procedure, and to histological results. Results: Most patients were women (57%), and the mean age was 53.0 ± 16.4 years. In 139 cases (74.6%), there was diagnostic suspicion of metastasis and the most common primary tumors were breast (32.1%) and prostate (11.8%). The bones most commonly involved were spine (36.0%), hip (32.8%) and long bones (18.3%). Complications occurred in only three cases (1.6%) including bone fracture, paraesthesia with functional impairment, and needle breakage requiring surgical removal. The specimens collected from 183 lesions (98.4%) were considered appropriate for diagnosis. Malignant results were more frequently found in patients who had a suspected secondary lesion and history of known malignancy (p < 0.001), and in patients who underwent PET/CT-guided procedures (p = 0.011). Conclusion: CT-guided percutaneous biopsy is a safe and effective procedure for the diagnosis of suspicious bone lesions. (author)

  20. Leak rate models and leak detection

    International Nuclear Information System (INIS)

    1992-01-01

    Leak detection may be carried out by a number of detection systems, but selection of the systems must be carefully adapted to the fluid state and the location of the leak in the reactor coolant system. Computer programs for the calculation of leak rates contain different models to take into account the fluid state before its entrance into the crack, and they have to be verified by experiments; agreement between experiments and calculations is generally not satisfactory for very small leak rates resulting from narrow cracks or from a closing bending moment

  1. Ultrasound-guided wire localization of lesions detected on ...

    African Journals Online (AJOL)

    Background: Wire localization for planned surgical treatment in the management of breast cancer is underutilized in our environment. The objective of this study is to assess the role of ultrasound-guided wire localization of breast masses detected on screening mammography and its impact on biopsy and breast ...

  2. Accuracy of the detection of infratentorial stroke lesions using perfusion CT: an experimenter-blinded study

    International Nuclear Information System (INIS)

    Lee, In Hyouk; Kim, Myung Soon; Kim, Young Ju; Lee, Myeong Sub; You, Joshua H.; Lee, Ji Yong; Whang, Kum

    2010-01-01

    Although perfusion CT (PCT) for the detection of supratentorial stroke is well established, there is a dearth of evidence of its effectiveness in the detection of infratentorial stroke. Hence, this study compared sensitivity, specificity, and accuracy of PCT maps between infratentorial and supratentorial stroke lesions. One hundred patients with acute stroke who had successfully undergone near whole-brain PCT with the toggling table technique and follow-up MRI were included. Wilcoxon Mann-Whitney test was performed at P 0.01 in all PCT maps) between supratentorial and infratentorial stroke. Also, there was no remarkable difference in both sensitivity and specificity of PCT maps. This was the first study to investigate the accuracy of PCT with the toggling table technique in detection of infratentorial stroke lesions. Clinically, PCT is highly reliable and accurate in detecting infratentorial stroke lesions. (orig.)

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

    Science.gov (United States)

    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.

  4. Can breast MRI computer-aided detection (CAD) improve radiologist accuracy for lesions detected at MRI screening and recommended for biopsy in a high-risk population?

    International Nuclear Information System (INIS)

    Arazi-Kleinman, T.; Causer, P.A.; Jong, R.A.; Hill, K.; Warner, E.

    2009-01-01

    Aim: To evaluate the sensitivity and specificity of magnetic resonance imaging (MRI) computer-aided detection (CAD) for breast MRI screen-detected lesions recommended for biopsy in a high-risk population. Material and methods: Fifty-six consecutive Breast Imaging Reporting and Data System (BI-RADS) 3-5 lesions with histopathological correlation [nine invasive cancers, 13 ductal carcinoma in situ (DCIS) and 34 benign] were retrospectively evaluated using a breast MRI CAD prototype (CAD-Gaea). CAD evaluation was performed separately and in consensus by two radiologists specializing in breast imaging, blinded to the histopathology. Thresholds of 50, 80, and 100% and delayed enhancement were independently assessed with CAD. Lesions were rated as malignant or benign according to threshold and delayed enhancement only and in combination. Sensitivities, specificities, and negative predictive values (NPV) were determined for CAD assessments versus pathology. Initial MRI BI-RADS interpretation without CAD versus CAD assessments were compared using paired binary diagnostic tests. Results: Threshold levels for lesion enhancement were: 50% to include all malignant (and all benign) lesions; and 100% for all invasive cancer and high-grade DCIS. Combined use of threshold and enhancement patterns for CAD assessment was best (73% sensitivity, 56% specificity and 76% NPV for all cancer). Sensitivities and NPV were better for invasive cancer (100%/100%) than for all malignancies (54%/76%). Radiologists' MRI interpretation was more sensitive than CAD (p = 0.05), but less specific (p = 0.001) for cancer detection. Conclusion: The breast MRI CAD system used could not improve the radiologists' accuracy for distinguishing all malignant from benign lesions, due to the poor sensitivity for DCIS detection.

  5. Lesion dehydration rate changes with the surface layer thickness during enamel remineralization

    Science.gov (United States)

    Chang, Nai-Yuan N.; Jew, Jamison M.; Fried, Daniel

    2018-02-01

    A transparent highly mineralized outer surface zone is formed on caries lesions during remineralization that reduces the permeability to water and plaque generated acids. However, it has not been established how thick the surface zone should be to inhibit the penetration of these fluids. Near-IR (NIR) reflectance coupled with dehydration can be used to measure changes in the fluid permeability of lesions in enamel and dentin. Based on our previous studies, we postulate that there is a strong correlation between the surface layer thickness and the rate of dehydration. In this study, the rates of dehydration for simulated lesions in enamel with varying remineralization durations were measured. Reflectance imaging at NIR wavelengths from 1400-2300 nm, which coincides with higher water absorption and manifests the greatest sensitivity to contrast changes during dehydration measurements, was used to image simulated enamel lesions. The results suggest that the relationship between surface zone thickness and lesion permeability is highly non-linear, and that a small increase in the surface layer thickness may lead to a significant decrease in permeability.

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

    Science.gov (United States)

    Nie, Shufang; Zhang, Jia; Martinez-Zaguilan, Raul; Sennoune, Souad; Hossen, Md Nazir; Lichtenstein, Alice H; Cao, Jun; Meyerrose, Gary E; Paone, Ralph; Soontrapa, Suthipong; Fan, Zhaoyang; Wang, Shu

    2015-12-28

    Current approaches to the diagnosis and therapy of atherosclerosis cannot target 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 inflammatory responses. The presence of these cells is positively associated with lesion progression, severity and destabilization. Hence, they are an important diagnostic and therapeutic target. The objective of this study was to noninvasively assess the distribution and accumulation of intimal macrophages using CD36-targeted nanovesicles. Soy phosphatidylcholine was used to synthesize liposome-like nanovesicles. 1-(Palmitoyl)-2-(5-keto-6-octene-dioyl) phosphatidylcholine was incorporated on their surface to target the CD36 receptor. All in vitro data demonstrate that these targeted nanovesicles had a high binding affinity for the oxLDL binding site of the CD36 receptor and participated in CD36-mediated recognition and uptake of nanovesicles by macrophages. Intravenous administration into LDL receptor null mice of targeted compared to non-targeted nanovesicles resulted in higher uptake in aortic lesions. The nanovesicles co-localized with macrophages and their CD36 receptors in aortic lesions. This molecular target approach may facilitate the in vivo noninvasive imaging of atherosclerotic lesions in terms of intimal macrophage accumulation and distribution and disclose lesion features related to inflammation and possibly vulnerability thereby facilitate early lesion detection and targeted delivery of therapeutic compounds to intimal macrophages. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Giancardo, Luca [ORNL; Karnowski, Thomas Paul [ORNL; Chaum, Edward [ORNL; Meriaudeau, Fabrice [ORNL; Tobin Jr, Kenneth William [ORNL; Li, Yaquin [University of Tennessee, Knoxville (UTK)

    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.

  8. Temporal characteristics of radiologists’ and novices’ lesion detection in viewing medical images presented rapidly and sequentially

    Directory of Open Access Journals (Sweden)

    Ryoichi Nakashima

    2016-10-01

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

  9. Comparison of Digital Tomosynthesis and Chest Radiography for the Detection of Noncalcified Pulmonary and Hilar Lesions.

    Science.gov (United States)

    Galea, Angela; Adlan, Tarig; Gay, David; Roobottom, Carl; Dubbins, Paul; Riordan, Richard

    2015-09-01

    The aim of this study was to compare the sensitivity and specificity of chest digital tomosynthesis (DTS) with chest radiography (CXR) for the detection of noncalcified pulmonary nodules and hilar lesions using computed tomography (CT) as the reference standard. A total of 78 patients with suspected noncalcified pulmonary lesions on CXR were included in the study. Two radiologists, blinded to the history and CT, analyzed the CXR and the DTS images (separately), whereas a third radiologist analyzed the CXR and DTS images together. Noncalcified intrapulmonary nodules and hilar lesions were recorded for analysis. The interobserver agreement for CXR and DTS was assessed, and the time taken to report the images was recorded. A total of 202 lesions were recorded in 78 patients. There were 111 true lesions confirmed on CT in 53 patients; in 25 patients subsequent CT excluded a lesion. The overall sensitivity was 32% for CXR and 49% for DTS. This improved to 54% when the posteroanterior CXR and DTS were reviewed together (CXR-DTS). The overall specificities for CXR, DTS, and CXR-DTS were 49%, 96%, and 98%, respectively. There were 56 suspected hilar lesions with subgroup sensitivities of 76% for CXR, 65% for DTS, and 76% for CXR-DTS. The specificity for hilar lesions was 59%, 92%, and 97% for CXR, DTS, and CXR-DTS, respectively. DTS significantly improves the detectability of noncalcified nodules when compared with and when used in combination with CXR. The specificity and interobserver agreement of DTS in the diagnosis of suspected noncalcified pulmonary nodules and hilar lesions are significantly better than those of CXR and approaches those of CT.

  10. Revised PROPELLER for T2-weighted imaging of the prostate at 3 Tesla: impact on lesion detection and PI-RADS classification

    Energy Technology Data Exchange (ETDEWEB)

    Meier-Schroers, Michael; Marx, Christian; Schmeel, Frederic Carsten; Wolter, Karsten; Block, Wolfgang; Sprinkart, Alois Martin; Traeber, Frank; Schild, Hans Heinz; Kukuk, Guido Matthias [University Hospital Bonn, Department of Radiology, Bonn (Germany); Gieseke, Juergen [Philips Healthcare Germany, Hamburg (Germany); Willinek, Winfried [Hospital of Barmherzige Brueder, Department of Radiology, Neuroradiology, Sonography and Nuclear Medicine, Trier (Germany)

    2018-01-15

    To evaluate revised PROPELLER (RevPROP) for T2-weighted imaging (T2WI) of the prostate as a substitute for turbo spin echo (TSE). Three-Tesla MR images of 50 patients with 55 cancer-suspicious lesions were prospectively evaluated. Findings were correlated with histopathology after MRI-guided biopsy. T2 RevPROP, T2 TSE, diffusion-weighted imaging, dynamic contrast enhancement, and MR-spectroscopy were acquired. RevPROP was compared to TSE concerning PI-RADS scores, lesion size, lesion signal-intensity, lesion contrast, artefacts, and image quality. There were 41 carcinomas in 55 cancer-suspicious lesions. RevPROP detected 41 of 41 carcinomas (100%) and 54 of 55 lesions (98.2%). TSE detected 39 of 41 carcinomas (95.1%) and 51 of 55 lesions (92.7%). RevPROP showed fewer artefacts and higher image quality (each p < 0.001). No differences were observed between single and overall PI-RADS scores based on RevPROP or TSE (p = 0.106 and p = 0.107). Lesion size was not different (p = 0.105). T2-signal intensity of lesions was higher and T2-contrast of lesions was lower on RevPROP (each p < 0.001). For prostate cancer detection RevPROP is superior to TSE with respect to motion robustness, image quality and detection rates of lesions. Therefore, RevPROP might be used as a substitute for T2WI. (orig.)

  11. Revised PROPELLER for T2-weighted imaging of the prostate at 3 Tesla: impact on lesion detection and PI-RADS classification

    International Nuclear Information System (INIS)

    Meier-Schroers, Michael; Marx, Christian; Schmeel, Frederic Carsten; Wolter, Karsten; Block, Wolfgang; Sprinkart, Alois Martin; Traeber, Frank; Schild, Hans Heinz; Kukuk, Guido Matthias; Gieseke, Juergen; Willinek, Winfried

    2018-01-01

    To evaluate revised PROPELLER (RevPROP) for T2-weighted imaging (T2WI) of the prostate as a substitute for turbo spin echo (TSE). Three-Tesla MR images of 50 patients with 55 cancer-suspicious lesions were prospectively evaluated. Findings were correlated with histopathology after MRI-guided biopsy. T2 RevPROP, T2 TSE, diffusion-weighted imaging, dynamic contrast enhancement, and MR-spectroscopy were acquired. RevPROP was compared to TSE concerning PI-RADS scores, lesion size, lesion signal-intensity, lesion contrast, artefacts, and image quality. There were 41 carcinomas in 55 cancer-suspicious lesions. RevPROP detected 41 of 41 carcinomas (100%) and 54 of 55 lesions (98.2%). TSE detected 39 of 41 carcinomas (95.1%) and 51 of 55 lesions (92.7%). RevPROP showed fewer artefacts and higher image quality (each p < 0.001). No differences were observed between single and overall PI-RADS scores based on RevPROP or TSE (p = 0.106 and p = 0.107). Lesion size was not different (p = 0.105). T2-signal intensity of lesions was higher and T2-contrast of lesions was lower on RevPROP (each p < 0.001). For prostate cancer detection RevPROP is superior to TSE with respect to motion robustness, image quality and detection rates of lesions. Therefore, RevPROP might be used as a substitute for T2WI. (orig.)

  12. Application of a conversion factor to estimate the adenoma detection rate from the polyp detection rate.

    LENUS (Irish Health Repository)

    Francis, Dawn L

    2011-03-01

    The adenoma detection rate (ADR) is a quality benchmark for colonoscopy. Many practices find it difficult to determine the ADR because it requires a combination of endoscopic and histologic findings. It may be possible to apply a conversion factor to estimate the ADR from the polyp detection rate (PDR).

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

    Science.gov (United States)

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

    2009-02-01

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

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

    International Nuclear Information System (INIS)

    Qi, Jinyi

    2003-01-01

    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

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

    International Nuclear Information System (INIS)

    Holm, Jon; Loizou, Louiza; Albiin, Nils; Kartalis, Nikolaos; Leidner, Bertil; Sundin, Anders

    2012-01-01

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

  16. Diffusion-weighted imaging as part of hybrid PET/MRI protocols for whole-body cancer staging: Does it benefit lesion detection?

    Energy Technology Data Exchange (ETDEWEB)

    Buchbender, Christian, E-mail: christian.buchbender@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Hartung-Knemeyer, Verena, E-mail: verena.hartung@uk-essen.de [Univ Duisburg-Essen, Medical Faculty, Department of Nuclear Medicine, Hufelandstr. 55, D-45147 Essen (Germany); Beiderwellen, Karsten, E-mail: karsten.beiderwellen@uk-essen.de [Univ Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Hufelandstr. 55, D-45147 Essen (Germany); Heusch, Philipp, E-mail: philipp.heusch@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Kühl, Hilmar, E-mail: hilmar.kuehl@uni-due.de [Univ Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Hufelandstr. 55, D-45147 Essen (Germany); Lauenstein, Thomas C., E-mail: thomas.lauenstein@uk-essen.de [Univ Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Hufelandstr. 55, D-45147 Essen (Germany); Forsting, Michael, E-mail: michael.forsting@uk-essen.de [Univ Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Hufelandstr. 55, D-45147 Essen (Germany); Antoch, Gerald, E-mail: antoch@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Heusner, Till A., E-mail: heusner@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany)

    2013-05-15

    Purpose: Positron emission tomography/magnetic resonance imaging (PET/MRI) requires efficient scan protocols for whole-body cancer staging. The aim of this study was to evaluate if the application of diffusion-weighted MR imaging (DWI) results in a diagnostic benefit for lesion detection in oncologic patients if added to a whole-body [18F]-fluorodesoxyglucose ([18F]-FDG) PET/MRI protocol. Methods: 25 consecutive oncologic patients (16 men, 9 women; age 57 ± 12 years) prospectively underwent whole-body [18F]-FDG-PET/MRI including DWI on a hybrid PET/MRI scanner. A team of two readers assessed [18F]-FDG PET/MRI without DWI for primary tumors and metastases. In a second session, now considering DWI, readers reassessed [18F]-FDG PET/MRI accordingly. Additionally, the lesion-to-background contrast on [18F]-FDG PET and DWI was rated qualitatively (0, invisible; 1, low; 2, intermediate; 3, high). Wilcoxon's signed-rank test was performed to test for differences in the lesion-to-background contrast. Results: 49 lesions were detected in 16 patients (5 primaries, 44 metastases). All 49 lesions were concordantly detected by [18F]-FDG PET/MRI alone and [18F]-FDG PET/MRI with DWI. The lesion-to-background contrast on DWI compared to [18F]-FDG PET was rated lower in 22 (44.9%) of 49 detected lesions resulting in a significantly higher lesion-to-background contrast on [18F]-FDG PET compared to DWI (P = 0.001). Conclusions: DWI as part of whole-body [18F]-FDG PET/MRI does not benefit lesion detection. Given the necessity to optimize imaging protocols with regard to patient comfort and efficacy, DWI has to be questioned as a standard tool for whole-body staging in oncologic PET/MRI.

  17. Image covariance and lesion detectability in direct fan-beam x-ray computed tomography.

    Science.gov (United States)

    Wunderlich, Adam; Noo, Frédéric

    2008-05-21

    We consider noise in computed tomography images that are reconstructed using the classical direct fan-beam filtered backprojection algorithm, from both full- and short-scan data. A new, accurate method for computing image covariance is presented. The utility of the new covariance method is demonstrated by its application to the implementation of a channelized Hotelling observer for a lesion detection task. Results from the new covariance method and its application to the channelized Hotelling observer are compared with results from Monte Carlo simulations. In addition, the impact of a bowtie filter and x-ray tube current modulation on reconstruction noise and lesion detectability are explored for full-scan reconstruction.

  18. Image covariance and lesion detectability in direct fan-beam x-ray computed tomography

    International Nuclear Information System (INIS)

    Wunderlich, Adam; Noo, Frederic

    2008-01-01

    We consider noise in computed tomography images that are reconstructed using the classical direct fan-beam filtered backprojection algorithm, from both full- and short-scan data. A new, accurate method for computing image covariance is presented. The utility of the new covariance method is demonstrated by its application to the implementation of a channelized Hotelling observer for a lesion detection task. Results from the new covariance method and its application to the channelized Hotelling observer are compared with results from Monte Carlo simulations. In addition, the impact of a bowtie filter and x-ray tube current modulation on reconstruction noise and lesion detectability are explored for full-scan reconstruction

  19. Leak rate measurements and detection systems

    International Nuclear Information System (INIS)

    Kupperman, D.; Shack, W.J.; Claytor, T.

    1983-10-01

    A research program is under way to evaluate and develop improve leak detection systems. The primary focus of the work has been on acoustic emission detection of leaks. Leaks from artificial flaws, laboratory-generated IGSCCs and thermal fatigue cracks, and field-induced intergranular stress corrosion cracks (IGSCCs) from reactor piping have been examined. The effects of pressure, temperature, and leak rate and geometry on the acoustic signature are under study. The use of cross-correlation techniques for leak location and pattern recognition and autocorrelation for source discrimination is also being considered

  20. Evaluation of capsule endoscopy to detect mucosal lesions associated with gastrointestinal bleeding in dogs.

    Science.gov (United States)

    Davignon, D L; Lee, A C Y; Johnston, A N; Bowman, D D; Simpson, K W

    2016-03-01

    The objective of this study was to examine the utility of capsule endoscopy to detect mucosal abnormalities in dogs with gastrointestinal haemorrhage. Capsules were administered to 2 healthy controls and 8 patients with gastrointestinal haemorrhage. Images were evaluated for quality, gastric emptying time, small intestinal transit time and presence of lesions. There were no adverse effects of capsule endoscopy in dogs weighing from 7·7 to 58 kg. The capsule traversed the entire gastrointestinal tract in 5 of 8 patients, with high quality images obtained in the stomach and small intestine. Gastric emptying time and small intestinal transit time ranged from 1 to 270 and 15 to 180 minutes, respectively. In 3 of 8 patients, the capsule remained in the stomach despite pro-kinetics. Gastric lesions included mild haemorrhage and pinpoint erosion (4 of 8), a mass (1) and thickened bleeding pyloric mucosa (2). Two of 3 dogs with capsule retention had gastric lesions. Intestinal lesions included a healing duodenal ulcer, abnormal villi, ileal ulceration and colonic bleeding. Lesions identified by capsule endoscopy were considered a significant source of haemorrhage in 4 of 7 dogs with active bleeding. The relevance of pinpoint gastric mucosal erosions to blood loss is unclear. Capsule endoscopy can enable the non-invasive detection of gastric and small intestinal mucosal lesions in dogs presenting for evaluation of gastrointestinal bleeding. © 2016 British Small Animal Veterinary Association.

  1. Simultaneous Whole-Brain Segmentation and White Matter Lesion Detection Using Contrast-Adaptive Probabilistic Models

    DEFF Research Database (Denmark)

    Puonti, Oula; Van Leemput, Koen

    2016-01-01

    In this paper we propose a new generative model for simultaneous brain parcellation and white matter lesion segmentation from multi-contrast magnetic resonance images. The method combines an existing whole-brain segmentation technique with a novel spatial lesion model based on a convolutional...... restricted Boltzmann machine. Unlike current state-of-the-art lesion detection techniques based on discriminative modeling, the proposed method is not tuned to one specific scanner or imaging protocol, and simultaneously segments dozens of neuroanatomical structures. Experiments on a public benchmark dataset...... in multiple sclerosis indicate that the method’s lesion segmentation accuracy compares well to that of the current state-of-the-art in the field, while additionally providing robust whole-brain segmentations....

  2. Molecular detection of Leptospira spp. from canine kidney tissues and its association with renal lesions

    Directory of Open Access Journals (Sweden)

    Biswajit R. Dash

    2018-04-01

    Full Text Available Aim: The study aimed to detect the prevalence of Leptospira spp. in kidney tissues collected during necropsy and to establish its association with renal lesions in dogs of Mumbai region. Materials and Methods: Kidney tissues from 40 dogs were collected during necropsy after gross examination and then fixed in neutral buffered formalin and Bouin's fluid for histopathology and histochemistry, respectively. Kidney tissues were also collected for the detection of Leptospira spp. by polymerase chain reaction (PCR in a sterile container and stored at -80°C until further processing. Results: Of 40 cases studied, 13 (32.5% cases showed lesions of nephritis of varying histotype and severity. Glomerulonephritis was reported as the most common type of nephritis in 9 (69.23% cases, and interstitial nephritis was recorded in 4 (30.76% cases. Chronic and acute interstitial nephritis was observed in two cases each. Renal failure as a cause of death was found in 7 (17.5% dogs. Of a total of 40 cases, 9 were found positive for pathogenic Leptospira spp. genome by PCR. However, of nine PCR-positive cases, only four cases showed lesions in kidneys as glomerulonephritis and interstitial nephritis in two cases each. The rest five cases positive for Leptospira spp. by PCR did not show any appreciable lesions in the kidneys. Conclusion: Leptospiral DNA was detected in 9 (22.5% cases by PCR. Of these nine cases, only four cases showed renal lesions. Other five cases which were positive for Leptospira spp. by PCR did not show any appreciable gross and microscopic lesions in the kidneys which might be carriers for Leptospira spp. Considering variable reports on types of nephritis in Leptospira spp. infection and also the prevalence of non-pathogenic Leptospira spp., it is important to conduct an extensive study on the prevalence of Leptospira spp. and its association with renal lesions involving batteries of tests.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

    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. (paper)

  4. Evaluation of the application of chemical shift for the detection of lipid in brain lesion

    Energy Technology Data Exchange (ETDEWEB)

    Lim, C.J. [Department of Biomedical Imaging, Faculty of Medicine, University of Malaya Medical Centre, Kuala Lumpur (Malaysia); Ng, K.H., E-mail: ngkh@um.edu.m [Department of Biomedical Imaging, Faculty of Medicine, University of Malaya Medical Centre, Kuala Lumpur (Malaysia); Ramli, N.; Azman, R.R. [Department of Biomedical Imaging, Faculty of Medicine, University of Malaya Medical Centre, Kuala Lumpur (Malaysia)

    2011-02-15

    Non-invasive detection of the presence of lipids is particularly important in staging of intracranial tumours. Presence of lipid peak in aggressive intracranial tumours has been reported widely using MR spectroscopy. However this method has limitation due to long imaging time and artefacts formed by adjacent bones. Chemical shift MR imaging (with has shorter imaging time) is an alternative method that had been used to detect presence of lipid in vivo by means of signal intensity loss. The purpose of this study was to evaluate gradient echo in- and opposed-phase chemical shift pulse sequences for detection of lipid elements in brain lesion. Ten cylindered phantoms measuring 3 x 3 cm were filled with various mixtures of lipid and water: 0-90% lipid, in 10% step by weight. The gradient echo in- and opposed-phase chemical shift sequences were performed using a 1.5 T MRI (Magnetom Vision, Siemens) with a head coil. In addition, we performed MRI and chemical shift studies on 32 patients with brain lesion. We then analysed the association between out of phase intensity value and classification of the lesions. For phantom containing 50% lipid, maximum signal loss on opposed-phase images was observed. There were significant differences between in- and opposed-phase lipid-water phantom images (P = 0.0054). Most of the benign lesions fall into the positive out of phase intensity value, and malignant lesions fall into negative out of phase intensity value. We conclude that chemical shift artefact can be applied in detecting and characterising lipid elements in brain lesion.

  5. Ultrasonographic detection of focal liver lesions: increased sensitivity and specificity with microbubble contrast agents

    International Nuclear Information System (INIS)

    Hohmann, J.; Albrecht, T.; Hoffmann, C.W.; Wolf, K.-J.

    2003-01-01

    Ultrasonography (US) is the first choice for screening patients with suspected liver lesions. However, due to a lack of contrast agents, US used to be less sensitive and specific compared with computed tomography (CT) and magnet resonance imaging (MRI). The advent of microbubble contrast agents increased both sensitivity and specificity dramatically. Rapid developments of the contrast agents as well as of special imaging techniques were made in recent years. Today numerous different US imaging methods exist which based either on Doppler or on harmonic imaging. They are using the particular behaviour of microbubbles in a sound field which varies depending on the energy of insonation (low/high mechanical index, MI) as well as on the properties of the agent themselves. Apart from just blood pool enhancement some agents have a hepatosplenic specific late phase. US imaging during this late phase using relatively high MI in phase inversion mode (harmonic imaging) or stimulated acoustic emission (SAE; Doppler method) markedly improves the detection of focal liver lesions and is also very helpful for lesion characterisation. With regards to detection, contrast enhanced US performs similarly to CT as shown by recent studies. Early results of studies using low MI imaging and the newer perfluor agents are also showing promising results for lesion detection. Low MI imaging with these agents has the advantage of real time imaging and is particularly helpful for characterisation of focal lesions based on their dynamic contrast behaviour. Apart from the techniques which based on the morphology of liver lesions there were some attempts for the detection of occult metastases or micrometastases by means of liver blood flow changes. Also in this field the use of US contrast agents appears to have advantages over formerly used non contrast-enhanced methods although no conclusive results are available yet

  6. Evaluation of the application of chemical shift for the detection of lipid in brain lesion

    International Nuclear Information System (INIS)

    Lim, C.J.; Ng, K.H.; Ramli, N.; Azman, R.R.

    2011-01-01

    Non-invasive detection of the presence of lipids is particularly important in staging of intracranial tumours. Presence of lipid peak in aggressive intracranial tumours has been reported widely using MR spectroscopy. However this method has limitation due to long imaging time and artefacts formed by adjacent bones. Chemical shift MR imaging (with has shorter imaging time) is an alternative method that had been used to detect presence of lipid in vivo by means of signal intensity loss. The purpose of this study was to evaluate gradient echo in- and opposed-phase chemical shift pulse sequences for detection of lipid elements in brain lesion. Ten cylindered phantoms measuring 3 x 3 cm were filled with various mixtures of lipid and water: 0-90% lipid, in 10% step by weight. The gradient echo in- and opposed-phase chemical shift sequences were performed using a 1.5 T MRI (Magnetom Vision, Siemens) with a head coil. In addition, we performed MRI and chemical shift studies on 32 patients with brain lesion. We then analysed the association between out of phase intensity value and classification of the lesions. For phantom containing 50% lipid, maximum signal loss on opposed-phase images was observed. There were significant differences between in- and opposed-phase lipid-water phantom images (P = 0.0054). Most of the benign lesions fall into the positive out of phase intensity value, and malignant lesions fall into negative out of phase intensity value. We conclude that chemical shift artefact can be applied in detecting and characterising lipid elements in brain lesion.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    This study was designed to assess defect detectability in positron emission tomography (PET) imaging of abdominal lesions. 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). 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. 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

  8. The reliability of magnetic resonance imaging in traumatic brain injury lesion detection

    NARCIS (Netherlands)

    Geurts, B.H.J.; Andriessen, T.M.J.C.; Goraj, B.M.; Vos, P.E.

    2012-01-01

    Objective: This study compares inter-rater-reliability, lesion detection and clinical relevance of T2-weighted imaging (T2WI), Fluid Attenuated Inversion Recovery (FLAIR), T2*-gradient recalled echo (T2*-GRE) and Susceptibility Weighted Imaging (SWI) in Traumatic Brain Injury (TBI). Methods: Three

  9. Postmortem verification of MS cortical lesion detection with 3D DIR

    NARCIS (Netherlands)

    Seewann, A.M.; Kooi, E.J.; Roosendaal, S.D.; Pouwels, P.J.W.; Wattjes, M.P.; van der Valk, P.; Barkhof, F.; Polman, C.H.; Geurts, J.J.G.

    2012-01-01

    Objective: To assess the sensitivity and specificity of 3D double inversion recovery (DIR) MRI for detecting multiple sclerosis (MS) cortical lesions (CLs) using a direct postmortem MRI to histopathology comparison. Methods: Single-slab 3D DIR and 3D fluid-attenuated inversion recovery (FLAIR)

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

    Science.gov (United States)

    The Molecular and Cellular Characterization of Screen‐Detected Lesions ‐ Coordinating Center and Data Management Group will provide support for the participating studies responding to RFA CA14‐10. The coordinating center supports three main domains: network coordination, statistical support and computational analysis and protocol development and database support. Support for

  11. The spatial resolution of the porcine multifocal electroretinogram for detection of laser-induced retinal lesions

    DEFF Research Database (Denmark)

    Kyhn, Maria Voss; Kiilgaard, Jens Folke; Scherfig, Erik

    2008-01-01

    This study aimed to investigate the spatial resolution of a porcine multifocal electroretinogram (mfERG) protocol by testing its ability to detect laser-induced retinal lesions. Furthermore, we wanted to describe time-dependent changes in implicit time and amplitude of the different mfERG peaks...

  12. Rate of lens lesion development and the age of mice at time of irradiation

    International Nuclear Information System (INIS)

    Gajewski, A.K.; Majewska, K.; Slowikowska, M.G.

    1976-01-01

    The rate of lens lesion development has been studied in mice irradiated at different age ranging from one day up to one year old mice. The time needed for the first appearance of lens lesion was shortest in groups of mice irradiated at the age of one, two and three days of life, and longest in groups of mice irradiated at the age of 5 days, 1 week and 2 weeks of life. The time needed for the first appearance of lens lesion for mice irradiated between the third week and one year of life was constant. It was longer than for mice irradiated during the first three days of life and shorter than for mice irradiated at 5 up to 14 days of life. In all but one irradiated groups the age at which the first lens lesion occurred differed significantly from the age at which the first senile changes occurred in the lens of control mice. The one exception was the group of mice irradiated at the age of one year. (author)

  13. Role of multidetector computed tomography in evaluating incidentally detected breast lesions.

    Science.gov (United States)

    Moschetta, Marco; Scardapane, Arnaldo; Lorusso, Valentina; Rella, Leonarda; Telegrafo, Michele; Serio, Gabriella; Angelelli, Giuseppe; Ianora, Amato Antonio Stabile

    2015-01-01

    Computed tomography (CT) does not represent the primary method for the evaluation of breast lesions; however, it can detect breast abnormalities, even when performed for other reasons related to thoracic structures. The aim of this study is to evaluate the potential benefits of 320-row multidetector CT (MDCT) in evaluating and differentiating incidentally detected breast lesions by using vessel probe and 3D analysis software with net enhancement value. Sixty-two breast lesions in 46 patients who underwent 320-row chest CT examination were retrospectively evaluated. CT scans were assessed searching for the presence, location, number, morphological features, and density of breast nodules. Net enhancement was calculated by subtracting precontrast density from the density obtained by postcontrast values. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of CT were calculated for morphological features and net enhancement. Thirty of 62 lesions were found to be malignant at histological examination and 32 were found to be benign. When morphological features were considered, the sensitivity, specificity, accuracy, PPV, and NPV of CT were 87%, 100%, 88%, 100%, and 50%, respectively. Based on net enhancement, CT reached a sensitivity, specificity, accuracy, PPV, and NPV of 100%, 94%, 97%, 94%, and 100%, respectively. MDCT allows to recognize and characterize breast lesions based on morphological features. Net enhancement can be proposed as an additional accurate feature of CT.

  14. Impact of variations in fatty liver on sonographic detection of focal hepatic lesions originally identified by CT

    OpenAIRE

    Wu, Size; Tu, Rong; Nan, Ruixia; Liu, Guangqing; Cui, Xiaojing; Liang, Xian

    2015-01-01

    Purpose: The aim of this study was to investigate the influence of variations in fatty liver on the ultrasonographic detection of focal liver lesions. Methods: A total of 229 patients with varying degrees of fatty liver and focal liver lesions and 200 patients with focal liver lesions but no fatty liver were randomly selected for inclusion in groups I and II, respectively. Findings of focal liver lesions identified on computed tomography were taken as the reference, and findings on ultrasonog...

  15. Self-organizing neural networks for automatic detection and classification of contrast-enhancing lesions in dynamic MR-mammography

    International Nuclear Information System (INIS)

    Vomweg, T.W.; Teifke, A.; Kauczor, H.U.; Achenbach, T.; Rieker, O.; Schreiber, W.G.; Heitmann, K.R.; Beier, T.; Thelen, M.

    2005-01-01

    Purpose: Investigation and statistical evaluation of 'Self-Organizing Maps', a special type of neural networks in the field of artificial intelligence, classifying contrast enhancing lesions in dynamic MR-mammography. Material and Methods: 176 investigations with proven histology after core biopsy or operation were randomly divided into two groups. Several Self-Organizing Maps were trained by investigations of the first group to detect and classify contrast enhancing lesions in dynamic MR-mammography. Each single pixel's signal/time curve of all patients within the second group was analyzed by the Self-Organizing Maps. The likelihood of malignancy was visualized by color overlays on the MR-images. At last assessment of contrast-enhancing lesions by each different network was rated visually and evaluated statistically. Results: A well balanced neural network achieved a sensitivity of 90.5% and a specificity of 72.2% in predicting malignancy of 88 enhancing lesions. Detailed analysis of false-positive results revealed that every second fibroadenoma showed a 'typical malignant' signal/time curve without any chance to differentiate between fibroadenomas and malignant tissue regarding contrast enhancement alone; but this special group of lesions was represented by a well-defined area of the Self-Organizing Map. Discussion: Self-Organizing Maps are capable of classifying a dynamic signal/time curve as 'typical benign' or 'typical malignant'. Therefore, they can be used as second opinion. In view of the now known localization of fibroadenomas enhancing like malignant tumors at the Self-Organizing Map, these lesions could be passed to further analysis by additional post-processing elements (e.g., based on T2-weighted series or morphology analysis) in the future. (orig.)

  16. Lesion detection in ultra-wide field retinal images for diabetic retinopathy diagnosis

    Science.gov (United States)

    Levenkova, Anastasia; Sowmya, Arcot; Kalloniatis, Michael; Ly, Angelica; Ho, Arthur

    2018-02-01

    Diabetic retinopathy (DR) leads to irreversible vision loss. Diagnosis and staging of DR is usually based on the presence, number, location and type of retinal lesions. Ultra-wide field (UWF) digital scanning laser technology provides an opportunity for computer-aided DR lesion detection. High-resolution UWF images (3078×2702 pixels) may allow detection of more clinically relevant retinopathy in comparison with conventional retinal images as UWF imaging covers a 200° retinal area, versus 45° by conventional cameras. Current approaches to DR diagnosis that analyze 7-field Early Treatment Diabetic Retinopathy Study (ETDRS) retinal images provide similar results to UWF imaging. However, in 40% of cases, more retinopathy was found outside the 7- field ETDRS fields by UWF and in 10% of cases, retinopathy was reclassified as more severe. The reason is that UWF images examine both the central retina and more peripheral regions. We propose an algorithm for automatic detection and classification of DR lesions such as cotton wool spots, exudates, microaneurysms and haemorrhages in UWF images. The algorithm uses convolutional neural network (CNN) as a feature extractor and classifies the feature vectors extracted from colour-composite UWF images using a support vector machine (SVM). The main contribution includes detection of four types of DR lesions in the peripheral retina for diagnostic purposes. The evaluation dataset contains 146 UWF images. The proposed method for detection of DR lesion subtypes in UWF images using two scenarios for transfer learning achieved AUC ≈ 80%. Data was split at the patient level to validate the proposed algorithm.

  17. Comparative analysis of MR sequences to detect structural brain lesions in tuberous sclerosis

    International Nuclear Information System (INIS)

    Pinto Gama, Hugo Pereira; Campos Meirelles, Rogerio Goncalves de; Mendonca do Rego, Jose Iram; Rocha, Antonio Jose da; Silva, Carlos Jorge da; Braga, Flavio Tulio; Martins Maia, Antonio Carlos; Lederman, Henrique Manoel

    2006-01-01

    Tuberous sclerosis (TS) is a neurocutaneous genetically inherited disease with variable penetrance characterized by dysplasias and hamartomas affecting multiple organs. MR is the imaging method of choice to demonstrate structural brain lesions in TS. To compare MR sequences and determine which is most useful for the demonstration of each type of brain lesion in TS patients. We reviewed MR scans of 18 TS patients for the presence of cortical tubers, white matter lesions (radial bands), subependymal nodules, and subependymal giant cell astrocytoma (SGCA) on the following sequences: (1) T1-weighted spin-echo (T1 SE) images before and after gadolinium (Gd) injection; (2) nonenhanced T1 SE sequence with an additional magnetization transfer contrast medium pulse on resonance (T1 SE/MTC); and (3) fluid-attenuated inversion recovery (FLAIR) sequence. Cortical tubers were found in significantly (P<0.05) larger numbers and more conspicuously in FLAIR and T1 SE/MTC sequences. The T1 SE/MTC sequence was far superior to other methods in detecting white matter lesions (P<0.01). There was no significant difference between the T1 SE/MTC and T1 SE (before and after Gd injection) sequences in the detection of subependymal nodules; FLAIR sequence showed less sensitivity than the others in identifying the nodules. T1 SE sequences after Gd injection demonstrated better the limits of the SGCA. We demonstrated the importance of appropriate MRI sequences for diagnosis of the most frequent brain lesions in TS. Our study reinforces the fact that each sequence has a particular application according to the type of TS lesion. Gd injection might be useful in detecting SGCA; however, the parameters of size and location are also important for a presumptive diagnosis of these tumors. (orig.)

  18. Early Detection of Bone Lesions by Photoscanning with Radioactive Strontium-87m

    Energy Technology Data Exchange (ETDEWEB)

    Kostamis, P.; Constantinides, C.; Papavasiliou, C.; Binopoulos, D.; Sfontouris, J.; Malamos, B. [University of Athens Medical School, ' Alexandra' Hospital, Athens (Greece)

    1969-05-15

    Patients with proven and suspected bone lesions were scanned from 30 min to 3 h after an intravenous injection of 400 {mu}Ci to 1 mCi of {sup 87m}Sr. Many different types of bone tumours were detected, such as osteogenic sarcoma and metastatic cancer of breast, thyroid, lung and other organs. {sup 87m}Sr photoscanning easily demonstrates obvious tumours of the bone which have been visualized on the roentgenogram, but the most important purpose of the present study is the visualization of lesions which were not demonstrated on the conventional roentgenogram. The analysis of the examined cases is discussed. (author)

  19. The evaluation of the effect of attenuation correction on lesion detectability in whole-body FDG-PET

    International Nuclear Information System (INIS)

    Tomemori, Takashi; Uno, Kimiichi; Oka, Takashi; Suzuki, Takayuki; Tomiyoshi, Katsumi; Jin Wu

    2004-01-01

    The aim of this study was to compare the attenuation corrected and non-corrected FDG-PET images in patients with malignant lesions and to evaluate the effect of attenuation correction on lesion detectability. A total of 71 persons with 112 malignant lesions was examined. All subjects fasted for at least 4 hours before PET study and whole-body PET imaging was performed 45 min after the intravenous administration of FDG (mean dose: 273.8 MBq). Emission scans of 6 min and post-injection transmission scans of 6 min per bed position were used. The intensity of lesion uptake in FDG-PET image was visually classified into 3 grades; grade 2=the lesion was clearly identified in the maximum intensity projection (MIP) image of FDG-PET, grade 1=the lesion was not identified in MIP image but it can be identified in coronal image, grade 0=there was no contrast between lesion and background in both MIP and coronal image. Ninety-eight lesions (87.5%) were classified into same grade in both attenuation corrected and non-corrected image, but in 11 lesions (9.8%) attenuation corrected image was better lesion visualization than non-corrected image. All lesions divided between the primary lesions and the metastatic lesions. In 50 primary lesions, 43 lesions were depicted in both attenuation corrected and non-corrected image and other 7 lesions were not in both image. In 62 metastatic lesions, 50 lesions (80.7%) were classified into same grade in both attenuation corrected and non-corrected image, but in 10 lesions (16.1%) attenuation corrected image were better lesion visualization than non-corrected image. In the most cases, the lesions were depicted in both attenuation corrected and non-corrected image. In the primary lesions, the lesion detectability between attenuation corrected and non-corrected image was similar. But in some cases with the metastatic lesions, attenuation corrected image were better lesion visualization than non-corrected image. For asymptomatic patients, non

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

    Science.gov (United States)

    Han, Guilai; Jiao, Yuan

    2016-10-01

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

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

    Science.gov (United States)

    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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Computerized detection method for asymptomatic white matter lesions in brain screening MR images using a clustering technique

    International Nuclear Information System (INIS)

    Kunieda, Takuya; Uchiyama, Yoshikazu; Hara, Takeshi

    2008-01-01

    Asymptomatic white matter lesions are frequently identified by the screening system known as Brain Dock, which is intended for the detection of asymptomatic brain diseases. The detection of asymptomatic white matter lesions is important because their presence is associated with an increased risk of stroke. Therefore, we have developed a computerized method for the detection of asymptomatic white matter lesions in order to assist radiologists in image interpretation as a ''second opinion''. Our database consisted of T 1 - and T 2 -weighted images obtained from 73 patients. The locations of the white matter lesions were determined by an experienced neuroradiologist. In order to restrict the area to be searched for white matter lesions, we first segmented the cerebral region in T 1 -weighted images by applying thresholding and region-growing techniques. To identify the initial candidate lesions, k-means clustering with pixel values in T 1 - and T 2 -weighted images was applied to the segmented cerebral region. To eliminate false positives (FPs), we determined the features, such as location, size, and circularity, of each of the initial candidate lesions. Finally, a rule-based scheme and a quadratic discriminant analysis with these features were employed to distinguish between white matter lesions and FPs. The results showed that the sensitivity for the detection of white matter lesions was 93.2%, with 4.3 FPs per image, suggesting that our computerized method may be useful for the detection of asymptomatic white matter lesions in T 1 - and T 2 -weighted images. (author)

  3. Early dynamic 18F-FDG PET to detect hyperperfusion in hepatocellular carcinoma liver lesions.

    Science.gov (United States)

    Schierz, Jan-Henning; Opfermann, Thomas; Steenbeck, Jörg; Lopatta, Eric; Settmacher, Utz; Stallmach, Andreas; Marlowe, Robert J; Freesmeyer, Martin

    2013-06-01

    In addition to angiographic data on vascularity and vascular access, demonstration of hepatocellular carcinoma (HCC) liver nodule hypervascularization is a prerequisite for certain intrahepatic antitumor therapies. Early dynamic (ED) (18)F-FDG PET/CT could serve this purpose when the current standard method, contrast-enhanced (CE) CT, or other CE morphologic imaging modalities are unsuitable. A recent study showed ED (18)F-FDG PET/CT efficacy in this setting but applied a larger-than-standard (18)F-FDG activity and an elaborate protocol likely to hinder routine use. We developed a simplified protocol using standard activities and easily generated visual and descriptive or quantitative endpoints. This pilot study assessed the ability of these endpoints to detect HCC hyperperfusion and, thereby, evaluated the suitability in of the protocol everyday practice. Twenty-seven patients with 34 HCCs (diameter ≥ 1.5 cm) with hypervascularization on 3-phase CE CT underwent liver ED (18)F-FDG PET for 240 s, starting with (18)F-FDG (250-MBq bolus injection). Four frames at 15-s intervals, followed by 3 frames at 60-s intervals were reconstructed. Endpoints included focal tracer accumulation in the first 4 frames (60 s), subsequent focal washout, and visual and quantitative differences between tumor and liver regions of interest in maximum and mean ED standardized uptake value (ED SUVmax and ED SUVmean, respectively) 240-s time-activity curves. All 34 lesions were identified by early focal (18)F-FDG accumulation and faster time-to-peak ED SUVmax or ED SUVmean than in nontumor tissue. Tumor peak ED SUVmax and ED SUVmean exceeded liver levels in 85% and 53%, respectively, of lesions. Nadir tumor signal showed no consistent pattern relative to nontumor signal. HCC had a significantly shorter time to peak and significantly faster rate to peak for both ED SUVmax and ED SUVmean curves and a significantly higher peak ED SUVmax but not peak ED SUVmean than the liver. This pilot study

  4. Computerized detection of breast lesions in multi-centre and multi-instrument DCE-MR data using 3D principal component maps and template matching

    Science.gov (United States)

    Ertas, Gokhan; Doran, Simon; Leach, Martin O.

    2011-12-01

    In this study, we introduce a novel, robust and accurate computerized algorithm based on volumetric principal component maps and template matching that facilitates lesion detection on dynamic contrast-enhanced MR. The study dataset comprises 24 204 contrast-enhanced breast MR images corresponding to 4034 axial slices from 47 women in the UK multi-centre study of MRI screening for breast cancer and categorized as high risk. The scans analysed here were performed on six different models of scanner from three commercial vendors, sited in 13 clinics around the UK. 1952 slices from this dataset, containing 15 benign and 13 malignant lesions, were used for training. The remaining 2082 slices, with 14 benign and 12 malignant lesions, were used for test purposes. To prevent false positives being detected from other tissues and regions of the body, breast volumes are segmented from pre-contrast images using a fast semi-automated algorithm. Principal component analysis is applied to the centred intensity vectors formed from the dynamic contrast-enhanced T1-weighted images of the segmented breasts, followed by automatic thresholding to eliminate fatty tissues and slowly enhancing normal parenchyma and a convolution and filtering process to minimize artefacts from moderately enhanced normal parenchyma and blood vessels. Finally, suspicious lesions are identified through a volumetric sixfold neighbourhood connectivity search and calculation of two morphological features: volume and volumetric eccentricity, to exclude highly enhanced blood vessels, nipples and normal parenchyma and to localize lesions. This provides satisfactory lesion localization. For a detection sensitivity of 100%, the overall false-positive detection rate of the system is 1.02/lesion, 1.17/case and 0.08/slice, comparing favourably with previous studies. This approach may facilitate detection of lesions in multi-centre and multi-instrument dynamic contrast-enhanced breast MR data.

  5. Long-Term Primary Patency Rate After Nitinol Self-Expandable Stents Implantation in Long, Totally Occluded Femoropopliteal (TASC II C & D) Lesions.

    Science.gov (United States)

    Elmahdy, Mahmoud Farouk; Buonamici, Piergiovanni; Trapani, Maurizio; Valenti, Renato; Migliorini, Angela; Parodi, Guido; Antoniucci, David

    2017-06-01

    Endovascular therapy for long femoropopliteal lesions using percutaneous transluminal balloon angioplasty or first-generation of peripheral stents has been associated with unacceptable one-year restenosis rates. However, with recent advances in equipment and techniques, a better primary patency rate is expected. This study was conducted to detect the long-term primary patency rate of nitinol self-expandable stents implanted in long, totally occluded femoropopliteal lesions TransAtlantic Inter-Society Census (TASC II type C & D), and determine the predictors of reocclusion or restenosis in the stented segments. The demographics, clinical, anatomical, and procedural data of 213 patients with 240 de novo totally occluded femoropopliteal (TASC II type C & D) lesions treated with nitinol self-expandable stents were retrospectively analysed. Of these limbs, 159 (66.2%) presented with intermittent claudication, while 81 (33.8%) presented with critical limb ischaemia. The mean-time of follow-up was 36±22.6 months, (range: 6.3-106.2 months). Outcomes evaluated were, primary patency rate and predictors of reocclusion or restenosis in the stented segments. The mean age of the patients was 70.9±9.3 years, with male gender 66.2%. Mean pre-procedural ABI was 0.45±0.53. One-hundred-and-seventy-five (73%) lesions were TASC II type C, while 65 (27%) were type D lesions. The mean length of the lesions was 17.9±11.3mm. Procedure related complications occurred in 10 (4.1%) limbs. There was no periprocedural mortality. Reocclusion and restenosis were detected during follow-up in 45 and 30 limbs respectively, and all were re-treated by endovascular approach. None of the patients required major amputation. Primary patency rates were 81.4±1.1%, 77.7±1.9% and 74.4±2.8% at 12, 24, and 36 months respectively. Male gender, severe calcification, and TASC II D lesion were independent predictors for reocclusion, while predictors of restenosis were DM, smoking and TASC II D lesions

  6. Accuracy of the double contrast technique in the detection of small lesions of the colon

    Energy Technology Data Exchange (ETDEWEB)

    Muzzio, P C; Pomerri, F; Feltrin, G P; Biondetti, P R; Di Maggio, C [Padua Univ. (Italy). Istituto di Radiologia e Fisioterapia

    1979-02-01

    Double contrast enema has become an indispensible aid in early lesions of the colon, in particular for small lesions. According to the authors' opinion, the method provides so much additional information that it ought to be applied at all rates in such cases. It is neither expensive nor time-consuming and can easily be carried out in any X-ray department, especially where a fibroscope is not available. The results are reliable if the technique is applied correctly, if the patient is well-prepared, and if the radiologist has enough technical and semiological experience.

  7. Accuracy of the detection of infratentorial stroke lesions using perfusion CT: an experimenter-blinded study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, In Hyouk; Kim, Myung Soon; Kim, Young Ju; Lee, Myeong Sub [Yonsei University, Department of Radiology, Wonju College of Medicine, Wonju (Korea, Republic of); You, Joshua H. [Center for Health, Wellness, Fitness, Prevention, and Healing Across the Life Span, Department of Physical Therapy, Graduate School of Rehabilitation Science, Yonsei University, Center for Movement Impairment Solutions, Wonju City (Korea, Republic of); Lee, Ji Yong [Yonsei University, Department of Neurology, Wonju College of Medicine, Wonju (Korea, Republic of); Whang, Kum [Yonsei University, Department of Neurosurgery, Wonju College of Medicine, Wonju (Korea, Republic of)

    2010-12-15

    Although perfusion CT (PCT) for the detection of supratentorial stroke is well established, there is a dearth of evidence of its effectiveness in the detection of infratentorial stroke. Hence, this study compared sensitivity, specificity, and accuracy of PCT maps between infratentorial and supratentorial stroke lesions. One hundred patients with acute stroke who had successfully undergone near whole-brain PCT with the toggling table technique and follow-up MRI were included. Wilcoxon Mann-Whitney test was performed at P < 0.01. There was no significant statistical difference in the accuracy (91.79% vs. 93.23% in regional cerebral blood volume; 92.26% vs. 95.31% in regional cerebral blood flow; 89.17% vs. 92.71% in mean transit time; 89.76% vs. 92.19% in time to peak; P > 0.01 in all PCT maps) between supratentorial and infratentorial stroke. Also, there was no remarkable difference in both sensitivity and specificity of PCT maps. This was the first study to investigate the accuracy of PCT with the toggling table technique in detection of infratentorial stroke lesions. Clinically, PCT is highly reliable and accurate in detecting infratentorial stroke lesions. (orig.)

  8. Early detection of breast cancer mass lesions by mammogram segmentation images based on texture features

    International Nuclear Information System (INIS)

    Mahmood, F.H.

    2012-01-01

    Mammography is at present one of the available method for early detection of masses or abnormalities which is related to breast cancer.The calcifications. The challenge lies in early and accurate detection to overcome the development of breast cancer that affects more and more women throughout the world. Breast cancer is diagnosed at advanced stages with the help of the digital mammogram images. Masses appear in a mammogram as fine, granular clusters, which are often difficult to identify in a raw mammogram. The incidence of breast cancer in women has increased significantly in recent years. This paper proposes a computer aided diagnostic system for the extraction of features like mass lesions in mammograms for early detection of breast cancer. The proposed technique is based on a four-step procedure: (a) the preprocessing of the image is done, (b) regions of interest (ROI) specification, (c) supervised segmentation method includes two to stages performed using the minimum distance (M D) criterion, and (d) feature extraction based on Gray level Co-occurrence matrices GLC M for the identification of mass lesions. The method suggested for the detection of mass lesions from mammogram image segmentation and analysis was tested over several images taken from A L-llwiya Hospital in Baghdad, Iraq.The proposed technique shows better results.

  9. Drowsiness detection using heart rate variability.

    Science.gov (United States)

    Vicente, José; Laguna, Pablo; Bartra, Ariadna; Bailón, Raquel

    2016-06-01

    It is estimated that 10-30 % of road fatalities are related to drowsy driving. Driver's drowsiness detection based on biological and vehicle signals is being studied in preventive car safety. Autonomous nervous system activity, which can be measured noninvasively from the heart rate variability (HRV) signal obtained from surface electrocardiogram, presents alterations during stress, extreme fatigue and drowsiness episodes. We hypothesized that these alterations manifest on HRV and thus could be used to detect driver's drowsiness. We analyzed three driving databases in which drivers presented different sleep-deprivation levels, and in which each driving minute was annotated as drowsy or awake. We developed two different drowsiness detectors based on HRV. While the drowsiness episodes detector assessed each minute of driving as "awake" or "drowsy" with seven HRV derived features (positive predictive value 0.96, sensitivity 0.59, specificity 0.98 on 3475 min of driving), the sleep-deprivation detector discerned if a driver was suitable for driving or not, at driving onset, as function of his sleep-deprivation state. Sleep-deprivation state was estimated from the first three minutes of driving using only one HRV feature (positive predictive value 0.80, sensitivity 0.62, specificity 0.88 on 30 drivers). Incorporating drowsiness assessment based on HRV signal may add significant improvements to existing car safety systems.

  10. Lesion detection and vascular assessment with modified CTAP and MR imaging of liver

    International Nuclear Information System (INIS)

    Thoeni, R.F.; Werthmuller, W.C.; Warren, R.S.; Mulvihill, S.J.

    1990-01-01

    This paper reports on a special CT arterial portography (CTAP) method with immediate and delayed scans compared to MR imaging of liver with fat-saturation images and angiographic portogram to determine whether CTAP and MR imaging could obviate the angiographic portogram and which imaging method best detects lesions. In 13 patients, CTAP was obtained on a FASTRAK CT scanner in an immediate and delayed dynamic mode with 0.4-sec sections. These CT results were compared to the angiographic portogram and MR results of T1-weighted SR (TR 300, TE 20, NEX 4) and T2-weighted SE (TR 2,000--2,500; TE 20/70; NEX 2) W=with and without fat saturation. CT/MR features analyzed included lesion detection, involvement of portal and hepatic veins, and adenopathy. Features were ranked from 0 = definitely normal to 4 = definitely abnormal

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

    Science.gov (United States)

    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.

  12. Fecal-tagging CT colonography with structure-analysis electronic cleansing for detection of colorectal flat lesions

    International Nuclear Information System (INIS)

    Xu, Yonghua; Cai, Wenli; Nappi, Janne; Yoshida, Hiro

    2012-01-01

    Purpose: To evaluate the feasibility and sensitivity of the 3D-reading of fecal-tagging CT colonography (CTC) with a novel structure-analysis electronic cleansing (SAEC) in detecting colorectal flat lesions in comparison with a cleansed 3D reading with Viatronix V3D Colon system (V3D) and primary uncleansed 2D reading (2D). Materials and methods: Forty CTC cases with flat lesions were retrospectively observed. The Subjects from a multicenter clinical trial underwent cathartic bowel preparation with orally administrated barium-based fecal-tagging. Sixty-nine flat lesions were confirmed using colonoscopy and histopathology as a reference standard. The results from SAEC reading were compared with those of prospective V3D and 2D readings. Results: Overall detection sensitivity with SAEC was 52% (36/69), which was statistically higher than that of 32% (22/69) and 29% (20/69) with V3D and 2D readings, respectively (p < 0.05). The sensitivities in detecting not-on-fold flat lesions were 63% (24/38), 45% (17/38), and 42% (16/38) with SAEC, V3D, and 2D readings, respectively; whereas those of on-fold flat lesions were 39% (12/31), 16% (5/31), and 13% (4/31), respectively. None of the eight flat lesions (2-9 mm) at cecum was detected by any of the three reading methods. Excluding the flat lesions at cecum, the sensitivity with SAEC for detecting flat lesion ≥4 mm increased to 84% (31/37). Conclusions: The fecal-tagging CTC with structure-analysis electronic cleansing could yield a high sensitivity for detecting flat lesions ≥4 mm. The not-on-fold flat lesions were detected with higher sensitivity than on-fold flat lesions.

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

    Science.gov (United States)

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

    2017-06-01

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

  14. Scintigraphic detection of peptic lesions with the method of radiolabelled sucralfate

    International Nuclear Information System (INIS)

    Naumovski, J.; Kovkarova, E.; Simova, N.; Janevik-Ivanovska, E.; Georgievska- Kuzmanovska, S.

    2003-01-01

    Background. Sucralfate is an antiulcer agent that after peroral application strongly adheres to mucosal defects and in that way provides a protective barrier to further damage from acid and pepsin. If radiolabelled with a gamma isotope, it could be detected under a gamma camera pointing lesions to which it adhered. With the aim to confirm a suitable noninvasive method for investigation of caustic lesions of the upper gastrointestinal tract we evaluated in a preliminary study the validity of the radiolabelled Sucralfate scintigraphy in detection of peptic disease. Patients and methods. With that purpose, 35 patients after an endoscopic examination underwent scintigraphy with Tc-99m-DTPA sucralfate. Patients were divided in two groups: a group of 20 patients with endoscopic confirmed peptic disease and a control group of 15 persons who had not any disease of the upper gastrointestinal tract. Results. Using the test for clinical evaluation of a new method, the scan showed sensitivity of 75 %, specificity of 100 % and accuracy of 85.7 %. Conclusions. Scintigraphy with Tc-99m-DTPA Sucralfate promoting it as an additional method, complementary to routine investigations in detecting mucosal lesions. (author)

  15. Improved focal liver lesion detection by increasing flip angle during gadoxetic acid-enhancement in MRI

    International Nuclear Information System (INIS)

    Lee, Se Jy; Kim, Young Keun

    2015-01-01

    To study the differences of focal liver lesion image detection at 3 minute, 10 minute and 15 minute time points on gadoxetic acid (GA)’s enhanced MR imaging with a flip angle (FA) of 30° compared with a 11°. The subjects were 69 patients evaluated with GA enhanced MR imaging with 3.0T MR scanner. The patients are total 35(23 men and 7 women at the mean age of 60.4 years), hepatocellular carcinoma(23) and metastsis(12) except for normal, cyst and hemangioma. After GA was injected, FA 11° and 30° images were obtained at 3 minute, 10 minute and 15 minute time points respectively. After quantitative and qualitative assessment of each image was done, statistical analysis was performed by using the independent sample T-test. From both quantitative and qualitative assessment of 3 minute and 10 minute MR images after the injection of GA, FA 30° images was found to be superior than FA 11°, but there were no statistical significance. However, at 15 minute time point, Statistically significant FA 30° image(p<0.05) was better than FA 11° therefore, the FA 30° improves the focal liver lesion detection. FA 30° of MR image can detect liver lesion more sensitively than the existing FA11° image after GA contrast enhancement at 15 minute time point

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Morais, A. P. [Biomedical Engineering Program, COPPE, Rio de Janeiro (Brazil); Salgado de Oliveira University, Marechal Deodoro Street, 217 – Centro, Niterói, Rio de Janeiro (Brazil); Pino, A. V. [Biomedical Engineering Program, COPPE, Rio de Janeiro (Brazil); Souza, M. N. [Biomedical Engineering Program, COPPE, Rio de Janeiro (Brazil); Electronics Department at Polytechnic School, Federal University of Rio de Janeiro, Centro de Tecnologia Bloco H sala 217, Ilha do Fundão, Rio de Janeiro (Brazil)

    2016-08-15

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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.

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

    Science.gov (United States)

    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.

  20. Assessment of the breath motion correction on the detectability of lesions in PET oncology

    International Nuclear Information System (INIS)

    Marache-Francisco, S.

    2012-02-01

    Positron emission tomography (PET) is a nuclear medicine imaging technique that produces a three-dimensional image of functional processes in the body. The system detects pairs of gamma rays emitted by a tracer, which is introduced into the body. Three-dimensional images of tracer concentration within the body are then constructed by computer analysis. Respiratory motion in emission tomography leads to image blurring especially in the lower thorax and the upper abdomen, influencing this way the quantitative accuracy of PET measurements as well as leading to a loss of sensitivity in lesion detection. Although PET exams are getting shorter thanks to the improvement of scanner sensitivity, the current 2-3 minutes acquisitions per bed position are not yet compatible with patient breath-holding. Performing accurate respiratory motion correction without impairing the standard clinical protocol, i.e. without increasing the acquisition time, thus remains challenging. Different types of respiratory motion correction approaches have been proposed, mostly based on the use of non-rigid deformation fields either applied to the gated PET images or integrated during an iterative reconstruction algorithm. Evaluation of theses methods has been mainly focusing on the quantification and localization accuracy of small lesions, but their impact on the clinician detection performance during the diagnostic task has not been fully investigated yet. The purpose of this study is to address this question based on a computer assisted detection study. We evaluate the influence of two motion correction methods on the detection of small lesions in human oncology FDG PET images. This study is based on a series of realistic simulated whole-body FDG images based on the XCAT model. Detection performance is evaluated with a computer-aided detection system that we are developing for whole-body PET/CT images. Detection performances achieved with these two correction methods are compared with those

  1. Autofluorescence of pigmented skin lesions using a pulsed UV laser with synchronized detection: clinical results

    DEFF Research Database (Denmark)

    Cheng, Haynes Pak Hay; Svenmarker, Pontus; Tidemand-Lichtenberg, Peter

    2010-01-01

    signal, which may in turn produce high contrast images that improve diagnosis, even in the presence of ambient room light. The synchronized set-up utilizes a compact, diode pumped, pulsed UV laser at 355 nm which is coupled to a CCD camera and a liquid crystal tunable filter. The excitation and image......We report preliminary clinical results of autofluorescence imaging of malignant and benign skin lesions, using pulsed 355 nm laser excitation with synchronized detection. The novel synchronized detection system allows high signal-to-noise ratio to be achieved in the resulting autofluorescence...

  2. Detection of early lung cancer lesions in surgical resections and in bronchial and transbronchial biopsies

    International Nuclear Information System (INIS)

    Rott, T.; Jerse, M.; Tercelj, M.; Erzen, J.

    2006-01-01

    Background. Overall bad prognosis of lung cancer is mostly due to too late detection of early lung cancer, which may be treated with good success. Therefore, different diagnostic methods are developing for more efficient detection of early lung cancer: besides modern radiological, bronchoscopic methods with additional fluorescence techniques, quantitative cytological investigations, also histological and molecular investigations are included. Histology may reveal early preinvasive lung cancer lesions, associated early during multistep lung carcinogenesis with molecular genetic changes. Patients and methods. Preinvasive epithelial lung cancer lesions we searched in two groups of patients. In the first group of 316 patients from the period March 2003 - August 2006, 498 bronchial and transbronchial biopsies were examined for squamous metaplasia and dysplasia, carcinoma in situ, and invasive tumours. In the second group of 238 patients from the period January 2004 - August 2006, resected primary lung tumours were analysed for preinvasive and invasive neuroendocrine tumours and atypical adenomatous hyperplasia. Results. The most frequent changes in bronchial and transbronchial biopsies were squamous metaplasia (46.5%), simple or goblet cell hyperplasia of the bronchial epithelium (44.3%), malignant tumours (20.66%) and squamous dysplasia (16.1%), but rare carcinoma in situ (0.63%). Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia was found in 15 (6.3%) cases in the vicinity of 238 resected lung cancer specimens, carcinoid in 12 patients (5%), and mostly combined large cell neuroendocrine cancer in 21 patients (8.8%). Atypical adenomatous hyperplasia was found in 2 patients. Conclusions. Classical histological analysis should be focused on detection of early preinvasive epithelial lung cancer lesions. Additional available molecular investigations may reveal gradual genetic changes characteristic for a series of the preinvasive epithelial histological changes

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

    Science.gov (United States)

    Hu, Ping; Yang, Tie-jun

    2016-10-01

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

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

    Science.gov (United States)

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

    2012-01-01

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

  6. Impact of real-time virtual sonography, a coordinated sonography and MRI system that uses an image fusion technique, on the sonographic evaluation of MRI-detected lesions of the breast in second-look sonography.

    Science.gov (United States)

    Nakano, Shogo; Kousaka, Junko; Fujii, Kimihito; Yorozuya, Kyoko; Yoshida, Miwa; Mouri, Yukako; Akizuki, Miwa; Tetsuka, Rie; Ando, Takahito; Fukutomi, Takashi; Oshima, Yukihiko; Kimura, Junko; Ishiguchi, Tsuneo; Arai, Osamu

    2012-08-01

    The aim of this study was to verify the utility of second-look sonography using real-time virtual sonography (RVS)-a coordinated sonography with an MRI system that uses an image fusion technique with magnetic navigation-on the sonographic evaluation of MRI-detected lesions of the breast. Of the 196 consecutive patients who were examined with breast MRI in our hospital from 2006 to 2009, those patients who underwent second-look sonography to identify MRI-detected lesions were enrolled in this study. MRI was performed using a 1.5-T imager with the patient in a supine position. To assess the efficacy benefits of RVS, the correlations between lesion detection rates, MRI features, distribution, and histopathological classification on second-look sonography using conventional B-mode or RVS were analyzed. Of the 196 patients, 55 (28 %) demonstrated 67 lesions initially detected by MRI, followed by second-look sonography. Of the 67 MRI-detected lesions, 18 (30 %) were identified with second-look sonography using conventional B-mode alone, whereas 60 (90 %) lesions were detected with second-look sonography using RVS (p use of RVS on second-look sonography significantly increases the sonographic detection rate of MRI-detected lesions without operator dependence.

  7. The role of positron emission tomography in the detection of incidental gastrointestinal tract lesions in patients examined for lung cancer

    International Nuclear Information System (INIS)

    Isobe, Kazutoshi; Hata, Yoshinobu; Sakaguchi, Shinji; Takai, Yujiro; Shibuya, Kazutoshi; Takagi, Keigo; Homma, Sakae

    2010-01-01

    The purpose of this study was to clarify the clinical characteristics of lung cancer patients with abnormal accumulation in the gastrointestinal tract by fluoro-2-deoxyglucose positron emission tomography (PET). Of the 968 consecutive patients with primary lung cancer who underwent PET from October 2005 through September 2009, 26 patients had local abnormal accumulation in the gastrointestinal tract. We retrospectively compared the localization of abnormal accumulation in the gastrointestinal tract, standardized uptake value (SUV)max (1 hour), and the final clinical diagnosis. The site of abnormal accumulation was the esophagus in 1 case, the stomach in 8 and the small intestine to large intestine in 17. In 15 out of 26 (57%) cases with true PET positive results, there was esophageal cancer in 1 case, gastric cancer in 2, gastrointestinal stromal tumor in 1, colon cancer in 8, and 1 each of metastasis to the stomach, small intestine and large intestine from lung cancer. In 11 cases with false PET-positive results, there was a stomach polyp in 1 case, gastritis in 3, colon polyp in 1, diverticulitis in 1 and normal physiologic accumulation in 5. There were no differences in mean SUVmax among malignant lesions, benign lesions, and normal physiologic accumulation. We should perform endoscopy of the digestive tract to detect malignant lesions with high incidence rates when PET shows localalized abnormal accumulation in the gastrointestinal, tract in patients with lung cancer. (author)

  8. Lesion detection and quantification performance of the Tachyon-I time-of-flight PET scanner: phantom and human studies

    Science.gov (United States)

    Zhang, Xuezhu; Peng, Qiyu; Zhou, Jian; Huber, Jennifer S.; Moses, William W.; Qi, Jinyi

    2018-03-01

    The first generation Tachyon PET (Tachyon-I) is a demonstration single-ring PET scanner that reaches a coincidence timing resolution of 314 ps using LSO scintillator crystals coupled to conventional photomultiplier tubes. The objective of this study was to quantify the improvement in both lesion detection and quantification performance resulting from the improved time-of-flight (TOF) capability of the Tachyon-I scanner. We developed a quantitative TOF image reconstruction method for the Tachyon-I and evaluated its TOF gain for lesion detection and quantification. Scans of either a standard NEMA torso phantom or healthy volunteers were used as the normal background data. Separately scanned point source and sphere data were superimposed onto the phantom or human data after accounting for the object attenuation. We used the bootstrap method to generate multiple independent noisy datasets with and without a lesion present. The signal-to-noise ratio (SNR) of a channelized hotelling observer (CHO) was calculated for each lesion size and location combination to evaluate the lesion detection performance. The bias versus standard deviation trade-off of each lesion uptake was also calculated to evaluate the quantification performance. The resulting CHO-SNR measurements showed improved performance in lesion detection with better timing resolution. The detection performance was also dependent on the lesion size and location, in addition to the background object size and shape. The results of bias versus noise trade-off showed that the noise (standard deviation) reduction ratio was about 1.1–1.3 over the TOF 500 ps and 1.5–1.9 over the non-TOF modes, similar to the SNR gains for lesion detection. In conclusion, this Tachyon-I PET study demonstrated the benefit of improved time-of-flight capability on lesion detection and ROI quantification for both phantom and human subjects.

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

    Science.gov (United States)

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

    2014-08-01

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

  10. Fast approach to evaluate MAP reconstruction for lesion detection and localization

    International Nuclear Information System (INIS)

    Qi, Jinyi; Huesman, Ronald H.

    2004-01-01

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

  11. Management of breast lesions detectable only on MRI; Abklaerung ausschliesslich MRT-detektierbarer Mammalaesionen

    Energy Technology Data Exchange (ETDEWEB)

    Siegmann-Luz, K.C.; Bahrs, S.D.; Preibsch, H.; Hattermann, V.; Claussen, C.D. [Universitaetsklinikum Tuebingen (Germany). Abt. Diagnostische und Interventionelle Radiologie

    2014-01-15

    Breast MR imaging has become established as the most sensitive imaging method for diagnosing breast cancer. As a result of the increasing examination volume and improved image quality, the number of breast lesions detected only on MRI and requiring further clarification has risen in recent years. According to the S3-guideline 'Diagnosis, Therapy, and Follow-Up of Breast Cancer' as revised in July 2012, institutions performing breast MRI should provide the option of an MRI-guided intervention for clarification. This review describes the indications, methods and results of MRI-guided interventions for the clarification of breast lesions only visible on MRI. Recent guidelines and study results are also addressed and alternative methods and pitfalls are presented. (orig.)

  12. Clinical relevance of studies on the accuracy of visual inspection for detecting caries lesions

    DEFF Research Database (Denmark)

    Gimenez, Thais; Piovesan, Chaiana; Braga, Mariana M

    2015-01-01

    Although visual inspection is the most commonly used method for caries detection, and consequently the most investigated, studies have not been concerned about the clinical relevance of this procedure. Therefore, we conducted a systematic review in order to perform a critical evaluation considering...... the clinical relevance and methodological quality of studies on the accuracy of visual inspection for assessing caries lesions. Two independent reviewers searched several databases through July 2013 to identify papers/articles published in English. Other sources were checked to identify unpublished literature...... to clinical relevance and the methodological quality of the studies were evaluated. 96 of the 5,578 articles initially identified met the inclusion criteria. In general, most studies failed in considering some clinically relevant aspects: only 1 included study validated activity status of lesions, no study...

  13. MRI screening-detected breast lesions in high-risk young women: the value of targeted second-look ultrasound and imaging-guided biopsy.

    Science.gov (United States)

    Peter, P; Dhillon, R; Bose, S; Bourke, A

    2016-10-01

    To analyse the value of targeted second-look ultrasound and imaging-guided biopsy in high-risk young women eligible for screening magnetic resonance imaging (MRI) in a tertiary referral centre in Perth, Western Australia. A retrospective analysis of eligible high-risk young women who underwent screening breast MRI and targeted second-look ultrasound between June 2012 and June 2014 was performed with review of data. Over a 2-year period, 139 women underwent high-risk screening MRI. Of these, 30 women (with a total of 45 lesions) were recalled for targeted second-look ultrasound. Thirty-four MRI-detected lesions were identified on targeted ultrasound with 19 of them proceeding to ultrasound-guided biopsy, while the remaining 15 lesions were considered benign on ultrasound, were not biopsied, and were stable on follow-up imaging 12 months later. One lesion proceeded to an MRI-guided biopsy to confirm a benign result. Of the 11 lesions not seen on ultrasound, nine underwent MRI biopsy, one proceeded directly to hook wire localisation and excision, and one did not return for biopsy and was lost to follow-up. The overall biopsy rate was 14.4%. The cancer detection rate was 1.4%. The results of this study indicate that targeted second-look ultrasound and ultrasound-guided biopsy is a cost-effective and time-efficient approach for MRI-detected lesions in young women at high risk of developing breast cancer. MRI-guided biopsy should be considered for ultrasonographically occult suspicious lesions as there is a low, but definite, risk of cancer. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  14. Detection and analysis of human papillomavirus 16 and 18 homologous DNA sequences in oral lesions.

    Science.gov (United States)

    Wen, S; Tsuji, T; Li, X; Mizugaki, Y; Hayatsu, Y; Shinozaki, F

    1997-01-01

    The prevalence of human papillomavirus (HPV) 16 and 18 was investigated in oral lesions of the population of northeast China including squamous cell carcinomas (SCCs), candida leukoplakias, lichen planuses and papillomas, by southern blot hybridization with polymerase chain reaction (PCR). Amplified HPV16 and 18 E6 DNA was analyzed by cycle sequence. HPV DNA was detected in 14 of 45 SCCs (31.1%). HPV18 E6 DNA and HPV16 E6. DNA were detected in 24.4% and 20.0% of SCCs. respectively. Dual infection of both HPV 16 and HPV 18 was detected in 6 of 45 SCCs (13.3%), but not in other oral lesions. HPV 18 E6 DNA was also detected in 2 of 3 oral candida leukoplakias, but in none of the 5 papillomas. Our study indicated that HPV 18 infection might be more frequent than HPV 16 infection in oral SCCs in northeast Chinese, dual infection of high risk HPV types was restricted in oral SCCs, and that HPV infection might be involved in the pathogenesis of oral candida leukoplakia.

  15. Nonhemorrhagic brain lesions detected by magnetic resonance imaging in closed head injured patients

    International Nuclear Information System (INIS)

    Kinoshita, Yoshihiro; Hiraide, Atsushi; Yoshioka, Toshiji; Sugimoto, Tadashi; Ichimura, Teruhisa; Saito, Akira; Ohno, Yoshioki.

    1990-01-01

    This study evaluated the diagnostic usefulness of magnetic resonance imaging (MRI) in 83 closed head injured patients in whom CT failed to detect focal intra or extraaxial hematoma and/or apparent brain contusion. The patients were divided into three groups on the basis of unconsciousness duration: Group 1 comprised 50 patients diagnosed as having classical cerebral concussion; group 2 comprised 19 patients who presented to the hospital with 6-hr unconsciousness and was recovered within a week; and group 3 comprised 14 patients whose unconsciousness persisted for a week or more. There was no CT evidence of abnormal findings for group 1; and intraventricular hemorrhage and subarachnoid hemorrhage were visualized on CT in 26% and 16%, respectively, for group 2 and 71% and 14% for group 3. Intraaxial nonhemorrhagic lesions were detected on T2-weighted MRI. According to high signal intensity, diffuse axonal injury and cortical contusion could be distinguished; i.e., in the former the corpus callosum, basal ganglia, or brain stem showed a high signal intensity, and in the latter the frontal, temporal, or parietal lobe adjacent to the skull showed a low signal intensity. T2-weighted MRI revealed cortical contusion in 6% for group 1, 37% for group 2, and 14% for group 3; and diffuse axonal injury in 42% for group 2 and 79% for group 3. For 62 patients with normal CT findings, diffuse axonal injury was detected in 88%. There was a good correlation between intraventricular hemorrhage on CT and diffuse axonal injury on MRI. In conclusion, T2-weighted MRI was significantly superior to CT in detecting nonhemorrhagic lesions, and it was of great help for predicting neurologic recovery in closed head injured patients without apparent focal lesions on CT. (N.K.)

  16. Harmonizing FDG PET quantification while maintaining optimal lesion detection: prospective multicentre validation in 517 oncology patients

    International Nuclear Information System (INIS)

    Quak, Elske; Le Roux, Pierre-Yves; Robin, Philippe; Bourhis, David; Salaun, Pierre-Yves; Hofman, Michael S.; Callahan, Jason; Binns, David; Hicks, Rodney J.; Desmonts, Cedric; Aide, Nicolas

    2015-01-01

    Point-spread function (PSF) or PSF + time-of-flight (TOF) reconstruction may improve lesion detection in oncologic PET, but can alter quantitation resulting in variable standardized uptake values (SUVs) between different PET systems. This study aims to validate a proprietary software tool (EQ.PET) to harmonize SUVs across different PET systems independent of the reconstruction algorithm used. NEMA NU2 phantom data were used to calculate the appropriate filter for each PSF or PSF+TOF reconstruction from three different PET systems, in order to obtain EANM compliant recovery coefficients. PET data from 517 oncology patients were reconstructed with a PSF or PSF+TOF reconstruction for optimal tumour detection and an ordered subset expectation maximization (OSEM3D) reconstruction known to fulfil EANM guidelines. Post-reconstruction, the proprietary filter was applied to the PSF or PSF+TOF data (PSF EQ or PSF+TOF EQ ). SUVs for PSF or PSF+TOF and PSF EQ or PSF+TOF EQ were compared to SUVs for the OSEM3D reconstruction. The impact of potential confounders on the EQ.PET methodology including lesion and patient characteristics was studied, as was the adherence to imaging guidelines. For the 1380 tumour lesions studied, Bland-Altman analysis showed a mean ratio between PSF or PSF+TOF and OSEM3D of 1.46 (95 %CI: 0.86-2.06) and 1.23 (95 %CI: 0.95-1.51) for SUV max and SUV peak , respectively. Application of the proprietary filter improved these ratios to 1.02 (95 %CI: 0.88-1.16) and 1.04 (95 %CI: 0.92-1.17) for SUV max and SUV peak , respectively. The influence of the different confounding factors studied (lesion size, location, radial offset and patient's BMI) was less than 5 %. Adherence to the European Association of Nuclear Medicine (EANM) guidelines for tumour imaging was good. These data indicate that it is not necessary to sacrifice the superior lesion detection and image quality achieved by newer reconstruction techniques in the quest for harmonizing quantitative

  17. Screen film vs full-field digital mammography: image quality, detectability and characterization of lesions

    International Nuclear Information System (INIS)

    Obenauer, S.; Luftner-Nagel, S.; Heyden, D. von; Baum, F.; Grabbe, E.; Munzel, U.

    2002-01-01

    The objective of this study was to compare screen-film mammography (SFM) to full-field digital mammography (FFDM) regarding image quality as well as detectability and characterization of lesions using equivalent images of the same patient acquired with both systems. Two mammography units were used, one with a screen-film system (Senographe DMR) and the other with a digital detector (Senographe 2000D, both GEMS). Screen-film and digital mammograms were performed on 55 patients with cytologically or histologically proven tumors on the same day. Together with these, 75 digital mammograms of patients without tumor and the corresponding previous screen-film mammograms not older than 1.5 years were reviewed by three observers in a random order. Contrast, exposure, and the presence of artifacts were evaluated. Different details, such as the skin, the retromamillary region, and the parenchymal structures, were judged according to a three-point ranking scale. Finally, the detectability of microcalcifications and lesions were compared and correlated to histology. Image contrast was judged to be good in 76%, satisfactory in 20%, and unsatisfactory in 4% of screen-film mammograms. Digital mammograms were judged to be good in 99% and unsatisfactory in 1% of cases. Improper exposure of screen-film system occurred in 18% (10% overexposed and 8% underexposed). Digital mammograms were improperly exposed in 4% of all cases but were of acceptable quality after post-processing. Artifacts, most of them of no significance, were found in 78% of screen-film and in none of the digital mammograms. Different anatomical regions, such as the skin, the retromamillary region, and dense parenchymal areas, were better visualized in digital than in screen-film mammography. All malignant tumors were seen by the three radiologists; however, digital mammograms allowed a better characterization of these lesions to the Breast Imaging Reporting and Data System (BI-RADSZZZ;) categories (FFDM better than

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

    Energy Technology Data Exchange (ETDEWEB)

    Salvagnini, Elena, E-mail: elena.salvagnini@gmail.com [Department of Imaging and Pathology, Radiology, KUL, Herestraat 49, Leuven B-3000 (Belgium); SCK-CEN, Boeretang 200, Mol 2400 (Belgium); Bosmans, Hilde; Marshall, Nicholas W. [Department of Imaging and Pathology, Radiology, KUL, Herestraat 49, Leuven B-3000 (Belgium); Department of Radiology, Radiology, UZ Gasthuisberg, Herestraat 49, Leuven B-3000 (Belgium); Van Ongeval, Chantal; Van Steen, Andreas; Cockmartin, Lesley [Department of Radiology, Radiology, UZ Gasthuisberg, Herestraat 49, Leuven B-3000 (Belgium); Michielsen, Koen [Department of Imaging and Pathology, Nuclear Medicine and Molecular Imaging, KUL, Herestraat 49, Leuven B-3000 (Belgium); Struelens, Lara [SCK-CEN, Boeretang 200, Mol 2400 (Belgium)

    2016-09-15

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

  19. Automatic Detection of Lung and Liver Lesions in 3-D Positron Emission Tomography Images: A Pilot Study

    Science.gov (United States)

    Lartizien, Carole; Marache-Francisco, Simon; Prost, Rémy

    2012-02-01

    Positron emission tomography (PET) using fluorine-18 deoxyglucose (18F-FDG) has become an increasingly recommended tool in clinical whole-body oncology imaging for the detection, diagnosis, and follow-up of many cancers. One way to improve the diagnostic utility of PET oncology imaging is to assist physicians facing difficult cases of residual or low-contrast lesions. This study aimed at evaluating different schemes of computer-aided detection (CADe) systems for the guided detection and localization of small and low-contrast lesions in PET. These systems are based on two supervised classifiers, linear discriminant analysis (LDA) and the nonlinear support vector machine (SVM). The image feature sets that serve as input data consisted of the coefficients of an undecimated wavelet transform. An optimization study was conducted to select the best combination of parameters for both the SVM and the LDA. Different false-positive reduction (FPR) methods were evaluated to reduce the number of false-positive detections per image (FPI). This includes the removal of small detected clusters and the combination of the LDA and SVM detection maps. The different CAD schemes were trained and evaluated based on a simulated whole-body PET image database containing 250 abnormal cases with 1230 lesions and 250 normal cases with no lesion. The detection performance was measured on a separate series of 25 testing images with 131 lesions. The combination of the LDA and SVM score maps was shown to produce very encouraging detection performance for both the lung lesions, with 91% sensitivity and 18 FPIs, and the liver lesions, with 94% sensitivity and 10 FPIs. Comparison with human performance indicated that the different CAD schemes significantly outperformed human detection sensitivities, especially regarding the low-contrast lesions.

  20. MRI detection of hypointense brain lesions in patients with multiple sclerosis: T1 spin-echo vs. gradient-echo

    Energy Technology Data Exchange (ETDEWEB)

    Dupuy, Sheena L.; Tauhid, Shahamat; Kim, Gloria; Chu, Renxin; Tummala, Subhash [Departments of Neurology, Brigham and Women' s Hospital, Laboratory for Neuroimaging Research, Partners MS Center, Harvard Medical School, Boston, MA (United States); Hurwitz, Shelley [Departments of Medicine, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States); Bakshi, Rohit, E-mail: rbakshi@bwh.harvard.edu [Departments of Neurology, Brigham and Women' s Hospital, Laboratory for Neuroimaging Research, Partners MS Center, Harvard Medical School, Boston, MA (United States); Departments of Radiology, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States)

    2015-08-15

    Highlights: • Compared T1SE and T1GE in detecting hypointense brain lesions in MS patients. • T1GE detected a higher cerebral lesion volume and number than T1SE. • T1SE correlated significantly with disability, while T1GE did not. • Hypointense lesions on T1SE and T1GE are not interchangeable in patients with MS. - Abstract: Objective: Compare T1 spin-echo (T1SE) and T1 gradient-echo (T1GE) sequences in detecting hypointense brain lesions in multiple sclerosis (MS). Background: Chronic hypointense lesions on T1SE MRI scans are a surrogate of severe demyelination and axonal loss in MS. The role of T1GE images in the detection of such lesions has not been clarified. Design/methods: In 45 patients with MS [Expanded Disability Status Scale (EDSS) score (mean ± SD) 3.5 ± 2.0; 37 relapsing-remitting (RR); 8 secondary progressive (SP)], cerebral T1SE, T1GE, and T2-weighted fluid-attenuated inversion-recovery (FLAIR) images were acquired on a 1.5 T MRI scanner. Images were re-sampled to axial 5 mm slices before directly comparing lesion detectability using Jim (v.7, Xinapse Systems). Statistical methods included Wilcoxon signed rank tests to compare sequences and Spearman correlations to test associations. Results: Considering the entire cohort, T1GE detected a higher lesion volume (5.90 ± 6.21 vs. 4.17 ± 4.84 ml, p < 0.0001) and higher lesion number (27.82 ± 20.66 vs. 25.20 ± 20.43, p < 0.05) than T1SE. Lesion volume differences persisted when considering RR and SP patients separately (both p < 0.01). A higher lesion number by T1GE was seen only in the RR group (p < 0.05). When comparing correlations between lesion volume and overall neurologic disability (EDSS score), T1SE correlated with EDSS (Spearman r = 0.29, p < 0.05) while T1GE (r = 0.23, p = 0.13) and FLAIR (r = 0.24, p = 0.12) did not. Conclusion: Our data suggest that hypointense lesions on T1SE and T1GE are not interchangeable in patients with MS. Based on these results, we hypothesize that T1GE

  1. MRI detection of hypointense brain lesions in patients with multiple sclerosis: T1 spin-echo vs. gradient-echo

    International Nuclear Information System (INIS)

    Dupuy, Sheena L.; Tauhid, Shahamat; Kim, Gloria; Chu, Renxin; Tummala, Subhash; Hurwitz, Shelley; Bakshi, Rohit

    2015-01-01

    Highlights: • Compared T1SE and T1GE in detecting hypointense brain lesions in MS patients. • T1GE detected a higher cerebral lesion volume and number than T1SE. • T1SE correlated significantly with disability, while T1GE did not. • Hypointense lesions on T1SE and T1GE are not interchangeable in patients with MS. - Abstract: Objective: Compare T1 spin-echo (T1SE) and T1 gradient-echo (T1GE) sequences in detecting hypointense brain lesions in multiple sclerosis (MS). Background: Chronic hypointense lesions on T1SE MRI scans are a surrogate of severe demyelination and axonal loss in MS. The role of T1GE images in the detection of such lesions has not been clarified. Design/methods: In 45 patients with MS [Expanded Disability Status Scale (EDSS) score (mean ± SD) 3.5 ± 2.0; 37 relapsing-remitting (RR); 8 secondary progressive (SP)], cerebral T1SE, T1GE, and T2-weighted fluid-attenuated inversion-recovery (FLAIR) images were acquired on a 1.5 T MRI scanner. Images were re-sampled to axial 5 mm slices before directly comparing lesion detectability using Jim (v.7, Xinapse Systems). Statistical methods included Wilcoxon signed rank tests to compare sequences and Spearman correlations to test associations. Results: Considering the entire cohort, T1GE detected a higher lesion volume (5.90 ± 6.21 vs. 4.17 ± 4.84 ml, p < 0.0001) and higher lesion number (27.82 ± 20.66 vs. 25.20 ± 20.43, p < 0.05) than T1SE. Lesion volume differences persisted when considering RR and SP patients separately (both p < 0.01). A higher lesion number by T1GE was seen only in the RR group (p < 0.05). When comparing correlations between lesion volume and overall neurologic disability (EDSS score), T1SE correlated with EDSS (Spearman r = 0.29, p < 0.05) while T1GE (r = 0.23, p = 0.13) and FLAIR (r = 0.24, p = 0.12) did not. Conclusion: Our data suggest that hypointense lesions on T1SE and T1GE are not interchangeable in patients with MS. Based on these results, we hypothesize that T1GE

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Schmaranzer, Florian; Klauser, Andrea; Henninger, Benjamin [Medical University Innsbruck, Department of Radiology, Innsbruck (Austria); Kogler, Michael; Schmaranzer, Ehrenfried [District Hospital St. Johann in Tyrol, Department of Radiology, St. Johann in Tyrol (Austria); Forstner, Thomas [Johannes Keppler University, Department for Applied Systems Research and Statistics, Linz (Austria); Reichkendler, Markus [District Hospital St. Johann in Tyrol, Department of Orthopedic Surgery, St. Johann in Tyrol (Austria)

    2015-06-01

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

  4. Real-time PCR detection of Brucella spp. DNA in lesions and viscera of bovine carcasses.

    Science.gov (United States)

    Sola, Marília Cristina; da Veiga Jardim, Eurione A G; de Freitas, Marcius Ribeiro; de Mesquita, Albenones José

    2014-09-01

    This study reports a real-time PCR assay for the detection of Brucella spp. associated with the FTA® Elute method in lesions observed during sanitary inspections in beef slaughter. Of the total 276 samples, 78 (28.3%) tested positive and 198 (71.7%) negative for Brucella spp. The real-time PCR technique associated with the FTA® Elute method proved to be an important tool for the diagnosis, judgment about and disposal of carcasses and viscera of slaughtered animals. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Claudin-4-targeted optical imaging detects pancreatic cancer and its precursor lesions.

    Science.gov (United States)

    Neesse, Albrecht; Hahnenkamp, Anke; Griesmann, Heidi; Buchholz, Malte; Hahn, Stefan A; Maghnouj, Abdelouahid; Fendrich, Volker; Ring, Janine; Sipos, Bence; Tuveson, David A; Bremer, Christoph; Gress, Thomas M; Michl, Patrick

    2013-07-01

    Novel imaging methods based on specific molecular targets to detect both established neoplasms and their precursor lesions are highly desirable in cancer medicine. Previously, we identified claudin-4, an integral constituent of tight junctions, as highly expressed in various gastrointestinal tumours including pancreatic cancer. Here, we investigate the potential of targeting claudin-4 with a naturally occurring ligand to visualise pancreatic cancer and its precursor lesions in vitro and in vivo by near-infrared imaging approaches. A non-toxic C-terminal fragment of the claudin-4 ligand Clostridium perfringens enterotoxin (C-CPE) was labelled with a cyanine dye (Cy5.5). Binding of the optical tracer was analysed on claudin-4 positive and negative cells in vitro, and tumour xenografts in vivo. In addition, two genetically engineered mouse models for pancreatic intraepithelial neoplasia (PanIN) and pancreatic cancer were used for in vivo validation. Optical imaging studies were conducted using 2D planar fluorescence reflectance imaging (FRI) technology and 3D fluorescence-mediated tomography (FMT). In vitro, the peptide-dye conjugate showed high binding affinity to claudin-4 positive CAPAN1 cells, while claudin-4 negative HT1080 cells revealed little or no fluorescence. In vivo, claudin-4 positive tumour xenografts, endogenous pancreatic tumours, hepatic metastases, as well as preinvasive PanIN lesions, were visualised by FRI and FMT up to 48 h after injection showing a significantly higher average of fluorochrome concentration as compared with claudin-4 negative xenografts and normal pancreatic tissue. C-CPE-Cy5.5 combined with novel optical imaging methods enables non-invasive visualisation of claudin-4 positive murine pancreatic tumours and their precursor lesions, representing a promising modality for early diagnostic imaging.

  6. Measuring telomere length for the early detection of precursor lesions of esophageal squamous cell carcinoma

    International Nuclear Information System (INIS)

    Lin, Shih-Wen; Wang, Guo-Qing; Wei, Wen-Qiang; Lu, Ning; Taylor, Philip R; Qiao, You-Lin; Dawsey, Sanford M; Abnet, Christian C; Freedman, Neal D; Murphy, Gwen; Risques, Rosana; Prunkard, Donna; Rabinovitch, Peter; Pan, Qin-Jing; Roth, Mark J

    2013-01-01

    Esophageal cancer is the sixth leading cause of cancer death worldwide; current early detection screening tests are inadequate. Esophageal balloon cytology successfully retrieves exfoliated and scraped superficial esophageal epithelial cells, but cytologic reading of these cells has poor sensitivity and specificity for detecting esophageal squamous dysplasia (ESD), the precursor lesion of esophageal squamous cell carcinoma (ESCC). Measuring telomere length, a marker for chromosomal instability, may improve the utility of balloon cytology for detecting ESD and early ESCC. We examined balloon cytology specimens from 89 asymptomatic cases of ESD (37 low-grade and 52 high-grade) and 92 age- and sex-matched normal controls from an esophageal cancer early detection screening study. All subjects also underwent endoscopy and biopsy, and ESD was diagnosed histopathologically. DNA was extracted from the balloon cytology cells, and telomere length was measured by quantitative PCR. A receiver operating characteristic (ROC) curve was plotted for telomere length as a diagnostic marker for high-grade dysplasia. Telomere lengths were comparable among the low- and high-grade dysplasia cases and controls, with means of 0.96, 0.96, and 0.92, respectively. The area under the ROC curve was 0.55 for telomere length as a diagnostic marker for high-grade dysplasia. Further adjustment for subject characteristics, including sex, age, smoking, drinking, hypertension, and body mass index did not improve the use of telomere length as a marker for ESD. Telomere length of esophageal balloon cytology cells was not associated with ESCC precursor lesions. Therefore, telomere length shows little promise as an early detection marker for ESCC in esophageal balloon samples

  7. Analysing the Progression Rates of Macular Lesions with Autofluorescence Imaging Modes in Dry Age-Related Macular Degeneration

    Directory of Open Access Journals (Sweden)

    Kenan Olcay

    2015-12-01

    Full Text Available Objectives: In this study we aimed to compare the sensitivity of blue-light fundus autofluorescence (FAF and near-infrared autofluorescence (NI-AF imaging for determining the progression rates of macular lesions in dry age-related macular degeneration (AMD. Materials and Methods: The study was designed retrospectively and included patients diagnosed with intermediate and advanced stage dry AMD. Best corrected visual acuities and FAF and NI-AF images were recorded in 46 eyes of 33 patients. Lesion borders were drawn manually on the images using Heidelberg Eye Explorer software and lesion areas were calculated by using Microsoft Excel software. BCVA and lesion areas were compared with each other. Results: Patients’ mean follow-up time was 30.98±13.30 months. The lesion area progression rates were 0.85±0.93 mm2/y in FAF and 0.93±1.01 mm2/y in NI-AF, showing statistically significant correlation with each other (r=0.883; p<0.01. Both imaging methods are moderately correlated with visual acuity impairment (r=0.362; p<0.05 and r=0.311; p<0.05, respectively. In addition, larger lesions showed higher progression rates than smaller ones in both imaging methods. Conclusion: NI-AF imaging is as important and effective as FAF imaging for follow-up of dry AMD patients.

  8. What affects detectability of lesion–deficit relationships in lesion studies?

    Directory of Open Access Journals (Sweden)

    Kayo Inoue

    2014-01-01

    Our simulations offer a quantitative basis for interpreting lesion studies in cognitive neuroscience. We suggest ways in which lesion simulation and analysis frameworks could be productively extended.

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

    International Nuclear Information System (INIS)

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

    2012-01-01

    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.

  10. An object-based approach for detecting small brain lesions: application to Virchow-Robin spaces.

    Science.gov (United States)

    Descombes, Xavier; Kruggel, Frithjof; Wollny, Gert; Gertz, Hermann Josef

    2004-02-01

    This paper is concerned with the detection of multiple small brain lesions from magnetic resonance imaging (MRI) data. A model based on the marked point process framework is designed to detect Virchow-Robin spaces (VRSs). These tubular shaped spaces are due to retraction of the brain parenchyma from its supplying arteries. VRS are described by simple geometrical objects that are introduced as small tubular structures. Their radiometric properties are embedded in a data term. A prior model includes interactions describing the clustering property of VRS. A Reversible Jump Markov Chain Monte Carlo algorithm (RJMCMC) optimizes the proposed model, obtained by multiplying the prior and the data model. Example results are shown on T1-weighted MRI datasets of elderly subjects.

  11. Autofluorescence of pigmented skin lesions using a pulsed UV laser with synchronized detection: clinical results

    Science.gov (United States)

    Cheng, Haynes P. H.; Svenmarker, Pontus; Xie, Haiyan; Tidemand-Lichtenberg, Peter; Jensen, Ole B.; Bendsoe, Niels; Svanberg, Katarina; Petersen, Paul Michael; Pedersen, Christian; Andersson-Engels, Stefan; Andersen, Peter E.

    2010-04-01

    We report preliminary clinical results of autofluorescence imaging of malignant and benign skin lesions, using pulsed 355 nm laser excitation with synchronized detection. The novel synchronized detection system allows high signal-tonoise ratio to be achieved in the resulting autofluorescence signal, which may in turn produce high contrast images that improve diagnosis, even in the presence of ambient room light. The synchronized set-up utilizes a compact, diode pumped, pulsed UV laser at 355 nm which is coupled to a CCD camera and a liquid crystal tunable filter. The excitation and image capture is sampled at 5 kHz and the resulting autofluorescence is captured with the liquid crystal filter cycling through seven wavelengths between 420 nm and 580 nm. The clinical study targets pigmented skin lesions and evaluates the prospects of using autofluorescence as a possible means in differentiating malignant and benign skin tumors. Up to now, sixteen patients have participated in the clinical study. The autofluorescence images, averaged over the exposure time of one second, will be presented along with histopathological results. Initial survey of the images show good contrast and diagnostic results show promising agreement based on the histopathological results.

  12. Detection of Carious Lesions and Restorations Using Particle Swarm Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Mohammad Naebi

    2016-01-01

    Full Text Available Background/Purpose. In terms of the detection of tooth diagnosis, no intelligent detection has been done up till now. Dentists just look at images and then they can detect the diagnosis position in tooth based on their experiences. Using new technologies, scientists will implement detection and repair of tooth diagnosis intelligently. In this paper, we have introduced one intelligent method for detection using particle swarm optimization (PSO and our mathematical formulation. This method was applied to 2D special images. Using developing of our method, we can detect tooth diagnosis for all of 2D and 3D images. Materials and Methods. In recent years, it is possible to implement intelligent processing of images by high efficiency optimization algorithms in many applications especially for detection of dental caries and restoration without human intervention. In the present work, we explain PSO algorithm with our detection formula for detection of dental caries and restoration. Also image processing helped us to implement our method. And to do so, pictures taken by digital radiography systems of tooth are used. Results and Conclusion. We implement some mathematics formula for fitness of PSO. Our results show that this method can detect dental caries and restoration in digital radiography pictures with the good convergence. In fact, the error rate of this method was 8%, so that it can be implemented for detection of dental caries and restoration. Using some parameters, it is possible that the error rate can be even reduced below 0.5%.

  13. Dissociation of Detection and Discrimination of Pure Tones following Bilateral Lesions of Auditory Cortex

    Science.gov (United States)

    Dykstra, Andrew R.; Koh, Christine K.; Braida, Louis D.; Tramo, Mark Jude

    2012-01-01

    It is well known that damage to the peripheral auditory system causes deficits in tone detection as well as pitch and loudness perception across a wide range of frequencies. However, the extent to which to which the auditory cortex plays a critical role in these basic aspects of spectral processing, especially with regard to speech, music, and environmental sound perception, remains unclear. Recent experiments indicate that primary auditory cortex is necessary for the normally-high perceptual acuity exhibited by humans in pure-tone frequency discrimination. The present study assessed whether the auditory cortex plays a similar role in the intensity domain and contrasted its contribution to sensory versus discriminative aspects of intensity processing. We measured intensity thresholds for pure-tone detection and pure-tone loudness discrimination in a population of healthy adults and a middle-aged man with complete or near-complete lesions of the auditory cortex bilaterally. Detection thresholds in his left and right ears were 16 and 7 dB HL, respectively, within clinically-defined normal limits. In contrast, the intensity threshold for monaural loudness discrimination at 1 kHz was 6.5±2.1 dB in the left ear and 6.5±1.9 dB in the right ear at 40 dB sensation level, well above the means of the control population (left ear: 1.6±0.22 dB; right ear: 1.7±0.19 dB). The results indicate that auditory cortex lowers just-noticeable differences for loudness discrimination by approximately 5 dB but is not necessary for tone detection in quiet. Previous human and Old-world monkey experiments employing lesion-effect, neurophysiology, and neuroimaging methods to investigate the role of auditory cortex in intensity processing are reviewed. PMID:22957087

  14. Dissociation of detection and discrimination of pure tones following bilateral lesions of auditory cortex.

    Science.gov (United States)

    Dykstra, Andrew R; Koh, Christine K; Braida, Louis D; Tramo, Mark Jude

    2012-01-01

    It is well known that damage to the peripheral auditory system causes deficits in tone detection as well as pitch and loudness perception across a wide range of frequencies. However, the extent to which to which the auditory cortex plays a critical role in these basic aspects of spectral processing, especially with regard to speech, music, and environmental sound perception, remains unclear. Recent experiments indicate that primary auditory cortex is necessary for the normally-high perceptual acuity exhibited by humans in pure-tone frequency discrimination. The present study assessed whether the auditory cortex plays a similar role in the intensity domain and contrasted its contribution to sensory versus discriminative aspects of intensity processing. We measured intensity thresholds for pure-tone detection and pure-tone loudness discrimination in a population of healthy adults and a middle-aged man with complete or near-complete lesions of the auditory cortex bilaterally. Detection thresholds in his left and right ears were 16 and 7 dB HL, respectively, within clinically-defined normal limits. In contrast, the intensity threshold for monaural loudness discrimination at 1 kHz was 6.5 ± 2.1 dB in the left ear and 6.5 ± 1.9 dB in the right ear at 40 dB sensation level, well above the means of the control population (left ear: 1.6 ± 0.22 dB; right ear: 1.7 ± 0.19 dB). The results indicate that auditory cortex lowers just-noticeable differences for loudness discrimination by approximately 5 dB but is not necessary for tone detection in quiet. Previous human and Old-world monkey experiments employing lesion-effect, neurophysiology, and neuroimaging methods to investigate the role of auditory cortex in intensity processing are reviewed.

  15. Dissociation of detection and discrimination of pure tones following bilateral lesions of auditory cortex.

    Directory of Open Access Journals (Sweden)

    Andrew R Dykstra

    Full Text Available It is well known that damage to the peripheral auditory system causes deficits in tone detection as well as pitch and loudness perception across a wide range of frequencies. However, the extent to which to which the auditory cortex plays a critical role in these basic aspects of spectral processing, especially with regard to speech, music, and environmental sound perception, remains unclear. Recent experiments indicate that primary auditory cortex is necessary for the normally-high perceptual acuity exhibited by humans in pure-tone frequency discrimination. The present study assessed whether the auditory cortex plays a similar role in the intensity domain and contrasted its contribution to sensory versus discriminative aspects of intensity processing. We measured intensity thresholds for pure-tone detection and pure-tone loudness discrimination in a population of healthy adults and a middle-aged man with complete or near-complete lesions of the auditory cortex bilaterally. Detection thresholds in his left and right ears were 16 and 7 dB HL, respectively, within clinically-defined normal limits. In contrast, the intensity threshold for monaural loudness discrimination at 1 kHz was 6.5 ± 2.1 dB in the left ear and 6.5 ± 1.9 dB in the right ear at 40 dB sensation level, well above the means of the control population (left ear: 1.6 ± 0.22 dB; right ear: 1.7 ± 0.19 dB. The results indicate that auditory cortex lowers just-noticeable differences for loudness discrimination by approximately 5 dB but is not necessary for tone detection in quiet. Previous human and Old-world monkey experiments employing lesion-effect, neurophysiology, and neuroimaging methods to investigate the role of auditory cortex in intensity processing are reviewed.

  16. A new automated quantification algorithm for the detection and evaluation of focal liver lesions with contrast-enhanced ultrasound.

    Science.gov (United States)

    Gatos, Ilias; Tsantis, Stavros; Spiliopoulos, Stavros; Skouroliakou, Aikaterini; Theotokas, Ioannis; Zoumpoulis, Pavlos; Hazle, John D; Kagadis, George C

    2015-07-01

    Detect and classify focal liver lesions (FLLs) from contrast-enhanced ultrasound (CEUS) imaging by means of an automated quantification algorithm. The proposed algorithm employs a sophisticated segmentation method to detect and contour focal lesions from 52 CEUS video sequences (30 benign and 22 malignant). Lesion detection involves wavelet transform zero crossings utilization as an initialization step to the Markov random field model toward the lesion contour extraction. After FLL detection across frames, time intensity curve (TIC) is computed which provides the contrast agents' behavior at all vascular phases with respect to adjacent parenchyma for each patient. From each TIC, eight features were automatically calculated and employed into the support vector machines (SVMs) classification algorithm in the design of the image analysis model. With regard to FLLs detection accuracy, all lesions detected had an average overlap value of 0.89 ± 0.16 with manual segmentations for all CEUS frame-subsets included in the study. Highest classification accuracy from the SVM model was 90.3%, misdiagnosing three benign and two malignant FLLs with sensitivity and specificity values of 93.1% and 86.9%, respectively. The proposed quantification system that employs FLLs detection and classification algorithms may be of value to physicians as a second opinion tool for avoiding unnecessary invasive procedures.

  17. Real-time virtual sonography (RVS)-guided vacuum-assisted breast biopsy for lesions initially detected with breast MRI.

    Science.gov (United States)

    Uematsu, Takayoshi

    2013-12-01

    To report on our initial experiences with a new method of real-time virtual sonography (RVS)-guided 11-gauge vacuum-assisted breast biopsy for lesions that were initially detected with breast MRI. RVS-guided 11-gauge vacuum-assisted biopsy is performed when a lesion with suspicious characteristics is initially detected with breast MRI and is occult on mammography, sonography, and physical examination. Live sonographic images were co-registered to the previously loaded second-look spine contrast-enhanced breast MRI volume data to correlate the sonography and MR images. Six lesions were examined in six consecutive patients scheduled to undergo RVS-guided 11-gauge vacuum-assisted biopsy. One patient was removed from the study because of non-visualization of the lesion in the second-look spine contrast-enhanced breast MRI. Five patients with non-mass enhancement lesions were biopsied. The lesions ranged in size from 9 to 13 mm (mean 11 mm). The average procedural time, including the sonography and MR image co-registration time, was 25 min. All biopsies resulted in tissue retrieval. One was fibroadenomatous nodules, and those of four were fibrocystic changes. There were no complications during or after the procedures. RVS-guided 11-gauge vacuum-assisted breast biopsies provide a safe and effective method for the examination of suspicious lesions initially detected with MRI.

  18. Diagnostic Accuracy and Inter-Observer Agreement of Shoulder Magnetic Resonance Arthrography in the Detection of Labral Lesion and Assessment of Lesion Location

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ji Young; Song, Sook Yun; Choi, Jin Ha; Shin, Sang Jin [School of Medicine, Ewha Womans University, Mokdong Hospital, Seoul (Korea, Republic of)

    2012-11-15

    To evaluate the diagnostic accuracy and inter-observer agreement of magnetic resonance (MR) arthrography in the detection of labral lesions by location and to describe useful MR imaging findings of labral tears. Sixty-eight patients who underwent both pre-operative MR arthrography and arthroscopy were included. The location of the labrum was classified into anterior (2-6 o'clock), superior (12-2 o'clock), and posterior (6-12 o'clock). Sensitivity, specificity, accuracy, and inter-observer agreement of MR arthrography for the diagnosis of labral lesions by location were calculated. Frequency of MR imaging findings such as detachment, high signal intensity cleft, contour change, absence, and signal change of the labrum by location were analyzed. 35 anterior, 44 superior and 15 posterior labral lesions were detected by arthroscopy. The corresponding sensitivities were 91.4%, 79.5%, and 40.0%, specificities were 90.9%, 20.8%, and 86.8%, accuracies were 91.2%, 58.8%, and 76.5%, and kappa values were 0.823, 0.252, and 0.394, for anterior, superior, posterior lesions, respectively. The most common MR imaging findings were detachment in 60.0% of anterior labrums, high signal intensity cleft in 52.3% of superior labrums, and normal in 60.0% of posterior labrums. Diagnostic accuracy and inter-observer agreement of MR arthrography in the diagnosis of labral lesions are high in anterior labrums and low in superior or posterior labrums. The useful MR imaging findings of labral tears were different according to labral location.

  19. Theoretical Analysis of Penalized Maximum-Likelihood Patlak Parametric Image Reconstruction in Dynamic PET for Lesion Detection.

    Science.gov (United States)

    Yang, Li; Wang, Guobao; Qi, Jinyi

    2016-04-01

    Detecting cancerous lesions is a major clinical application of emission tomography. In a previous work, we studied penalized maximum-likelihood (PML) image reconstruction for lesion detection in static PET. Here we extend our theoretical analysis of static PET reconstruction to dynamic PET. We study both the conventional indirect reconstruction and direct reconstruction for Patlak parametric image estimation. In indirect reconstruction, Patlak parametric images are generated by first reconstructing a sequence of dynamic PET images, and then performing Patlak analysis on the time activity curves (TACs) pixel-by-pixel. In direct reconstruction, Patlak parametric images are estimated directly from raw sinogram data by incorporating the Patlak model into the image reconstruction procedure. PML reconstruction is used in both the indirect and direct reconstruction methods. We use a channelized Hotelling observer (CHO) to assess lesion detectability in Patlak parametric images. Simplified expressions for evaluating the lesion detectability have been derived and applied to the selection of the regularization parameter value to maximize detection performance. The proposed method is validated using computer-based Monte Carlo simulations. Good agreements between the theoretical predictions and the Monte Carlo results are observed. Both theoretical predictions and Monte Carlo simulation results show the benefit of the indirect and direct methods under optimized regularization parameters in dynamic PET reconstruction for lesion detection, when compared with the conventional static PET reconstruction.

  20. Comparing Melanoma Invasiveness in Dermatologist- versus Patient-Detected Lesions: A Retrospective Chart Review

    Directory of Open Access Journals (Sweden)

    Cindy L. Lamerson

    2012-01-01

    Full Text Available This study examined whether patient-identified melanomas were more advanced than dermatologist-identified tumors at routine clinic visits, and whether a personal or family history of skin cancer was associated with patterns of detection. A retrospective chart review was performed on melanoma patients (N=201 in a private dermatology clinic. Variables included age, gender, pattern of detection (i.e., patient or a board certified dermatologist, personal or family history of skin cancer, skin type, and previous sun exposure, as well as tumor location and severity. Dermatologist-diagnosed melanomas were less invasive (P<0.0005, and more likely present on the chest, back, and legs (P<0.01. Conversely, patient-identified lesions were more likely to occur on the face, neck and scalp, be associated with younger patients, and a family history of melanoma, but not other types of skin cancer (P<0.01. In a post-hoc analysis examining these factors as predictors of tumor invasiveness, only diagnostic source was significant. Specifically, dermatologist-identified tumors were significantly less invasive than patient-identified tumors. Although age, family history, and tumor location played roles in the early detection of melanomas, the most important factor was diagnostic source. Thus, board-certified dermatologists play a key role in the early detection of malignant melanoma.

  1. Proliferative changes in nonpalpable breast lesions detected by mammography; Alteraciones profiferativas de la mama en lesiones no palpables detectadas por mamografia

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    Vega, A.; Delgado, A.; Ortega, E.; Garijo, F. [Hospital Universitario Marques de Valdecilla. Santander (Spain); Mosquera, J.; Sogo, C.; Alvarez, A. [Complejo Hospitalario Juan Canalejo. La Coruna (Spain)

    2000-07-01

    To analyze retrospectively the radiological findings in nonpalpable breast lesions detected by mammography that lead to the performance of surgical biopsy, resulting in a histological diagnosis of proliferative breast disease with and without atypia. From two Spanish hospitals, 421 women with 429 biopsies indicative of the presence of proliferative breast disease with and without atypia were selected out of a total of 1252 surgical biopsies in nonpalpable lesions that proved to be benign. Age, personal and familial history of breast cancer, reason for requesting the mammography and radiological findings that had indicated the need for surgical biopsy were recorded for each patient. The diagnosis was proliferative breast disease (epithelial hyperplasia) in 347 women with 354 biopsies and atypical hyperplasia in the remaining 74 women with 75 biopsies, representing 28% and 6%, respectively, of the 1252 biopsies of lesions found to be benign. In 221 of the 354 cases of epithelial hyperplasia (62%) and 45 of the 75 cases of atypical hyperplasia (60%), the presence of calcifications was the most common radiological findings leading to biopsy (p<0.05). Parenchymal distortion, with or without calcifications, was the second most common radiological sign. The histological study revealed a close relationship between these proliferative events and radial scars. Calcifications are the radiological finding that most frequently indicate the need for surgical biopsy in nonpalpable lesions that results in a diagnosis of proliferative breast disease with and without atypia. (Author) 12 refs.

  2. Additional lesions detected in therapeutic scans with 177Lu-DOTATATE reflect higher affinity of 177Lu-DOTATATE for somatostatin receptors.

    Science.gov (United States)

    Mirzaei, Siroos; Bastati, Brigitte; Lipp, Rainer W; Knoll, Peter; Zojer, Niklas; Ludwig, Heinz

    2011-01-01

    Peptide receptor-targeted radionuclide therapy (PRRT) of somatostatin receptor (SR)-expressing neuroendocrine tumors (NETs) has become an established therapeutic option in patients with advanced NETs. The aim of this study was to compare the lesion detection rate of (99m)Tc-EDDA/HYNIC-TOC, a newly developed tracer for NET imaging, with (177)Lu-DOTATATE used for PRRT. 8 patients (4 women, 4 men, age range 46-76 years) with histologically proven NETs, who showed high SR loads by (99m)Tc-EDDA/HYNIC-TOC scintigraphy, were treated with (177)Lu-DOTATATE. After treatment, all patients were subjected to whole-body scintigraphy with additional low-dose single-photon emission computed tomography (SPECT-CT) of the chest and abdomen. All patients demonstrated (177)Lu-DOTATATE accumulation in all lesions previously detected by (99m)Tc- EDDA/HYNIC-TOC scintigraphy. Three patients showed additional lesions in the liver and lungs. SPECT-CT after (177)Lu-DOTATATE therapy may be helpful in detecting additional lesions not seen using (99m)Tc-EDDA/HYNIC-TOC. This could reflect the broader affinity of (177)Lu-DOTATATE for SRs compared with (99m)Tc-EDDA/HYNIC-TOC. Copyright © 2011 S. Karger AG, Basel.

  3. Evaluation of a radiographic method to detect tibial dyschondroplasia lesions in broilers

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    K Pelicia

    2012-06-01

    Full Text Available This study aimed at developing radiographic techniques for the early detection of dyschondroplastic lesions in the tibia of broilers. The experiment was carried out at the facilities of UNIFOR/MG and Formiga and UNIFENAS/ Alfenas with 420 one-day-old male Cobb broilers. At 20 days of age, all birds were radiographed and identified with an alpha-numeric metal ring in the right leg. At 40 days of age, 42 broilers previously selected as a function of bone mineral density and lesion thickness scores were again radiographed and scored, and then sacrificed. Their right tibia was removed for gross and histological examination of the growth plate. The results showed that radiographic techniques are correlated with gross and histological examination and that there was no significant differences among techniques (P>0.05. it was concluded that the use of radiographic examination to identify tibial dyschondroplasia in broilers precludes the use of bone mineral density to diagnose this condition. The non-parametric statistical Chi-square test at 5% significance level was used to analyze the results.

  4. The role of second-look ultrasound of BIRADS-3 mammary lesions detected by breast MR imaging

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    Fiaschetti, V., E-mail: fiaschettivaleria@tin.it [Department of Imaging Diagnostic, Molecular Imaging, Interventional Radiology and Radiation Therapy University Hospital ' Tor Vergata' , 81 Oxford street, 00133 Rome (Italy); Salimbeni, C.; Gaspari, E.; Dembele, G. Kabunda; Bolacchi, F.; Cossu, E.; Pistolese, C.A.; Perretta, T.; Simonetti, G. [Department of Imaging Diagnostic, Molecular Imaging, Interventional Radiology and Radiation Therapy University Hospital ' Tor Vergata' , 81 Oxford street, 00133 Rome (Italy)

    2012-11-15

    Objective: To asses the value of second-look ultrasound (US) for identifying BIRADS 3 (Breast Imaging Reporting Data System) mammary lesions detected by breast Magnetic Resonance imaging (MRI). Materials and methods: From April 2008 to May 2009 330 breast MRI were performed of which 60 patients are classified as BIRADS 3. 84 lesions underwent second-look US and percutaneous vacuum biopsy Vacora system US-guided. Statistical analysis: lesions were stratified into two groups: visible on US (Group 1) and not visible on US (Group 2). The clinical impact of second-look US was studied in terms of negative predictive value (NPV). Results: The positive predictive value (PPV) of category 3 BIRADS MRI was found to be 89%. Second look-US results detected lesions in 51% of the MRI enhancing lesions. The second look-US showed a NPV of 97%. The NPV of second look-US was significantly greater than the NPV of MRI BIRADS 3 (97% vs 89%, p < 0.05). The logistic regression analysis showed a higher number of malignant lesions in group 1 than in group 2 (7vs 2, OR 3.7, p < 0.05). Conclusions: The second-look US permitted the correct management of subcentimetric MRI BIRADS 3 lesions not visible with conventional imaging tecniques.

  5. The role of second-look ultrasound of BIRADS-3 mammary lesions detected by breast MR imaging

    International Nuclear Information System (INIS)

    Fiaschetti, V.; Salimbeni, C.; Gaspari, E.; Dembele, G. Kabunda; Bolacchi, F.; Cossu, E.; Pistolese, C.A.; Perretta, T.; Simonetti, G.

    2012-01-01

    Objective: To asses the value of second-look ultrasound (US) for identifying BIRADS 3 (Breast Imaging Reporting Data System) mammary lesions detected by breast Magnetic Resonance imaging (MRI). Materials and methods: From April 2008 to May 2009 330 breast MRI were performed of which 60 patients are classified as BIRADS 3. 84 lesions underwent second-look US and percutaneous vacuum biopsy Vacora system US-guided. Statistical analysis: lesions were stratified into two groups: visible on US (Group 1) and not visible on US (Group 2). The clinical impact of second-look US was studied in terms of negative predictive value (NPV). Results: The positive predictive value (PPV) of category 3 BIRADS MRI was found to be 89%. Second look-US results detected lesions in 51% of the MRI enhancing lesions. The second look-US showed a NPV of 97%. The NPV of second look-US was significantly greater than the NPV of MRI BIRADS 3 (97% vs 89%, p < 0.05). The logistic regression analysis showed a higher number of malignant lesions in group 1 than in group 2 (7vs 2, OR 3.7, p < 0.05). Conclusions: The second-look US permitted the correct management of subcentimetric MRI BIRADS 3 lesions not visible with conventional imaging tecniques.

  6. Comparison between immediate and delayed imaging after gadolinium chelate injection for detecting enhanced lesions in multiple sclerosis

    International Nuclear Information System (INIS)

    Alizadeh, A.; Roudbari, A.; Heidarzadeh, A.; Kouhsari, M.

    2010-01-01

    Magnetic resonance imaging is a noninvasive and valuable method in the diagnosis of Multiple Sclerosis. Compared with other modalities, the sensitivity of Magnetic resonance imaging for detection of the lesion increases using magnetization transfer and delayed imaging. Our aim was to compare the two methods in detecting Multiple Sclerosis lesions. Patients and Methods: In this double-blind clinical trial, twenty-one patients with the definite diagnosis of Multiple Sclerosis referred to Poursina Hospital, Rasht were included. Two radiologists evaluated all the images. First, images without contrast were conducted, then 0.1 mmol/kg contrast material (Dotarem, single dose) was injected and after 30 minutes, T1W and magnetization transfer images were obtained. Seventy-two hours later, T1W images were obtained immediately after injection of 0.2 mmol/kg contrast material (double dose). The data were analyzed using Fisher's and McNemar tests by SPSS for Windows. Results: Delayed magnetization transfer showed 44 enhanced lesions using magnetization transfer (69.84%) and 29 lesions using T1 (46.03%). In addition, the number of enhanced lesions in the delayed method were significantly more than those in the immediate method (p value=0.003). Conclusion: The use of single dose in combination with magnetization transfer and delayed images after 20-30 minutes enables us to detect more enhanced lesions.

  7. Detection of small human cerebral cortical lesions with MRI under different levels of Gaussian smoothing: applications in epilepsy

    Science.gov (United States)

    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.

  8. OCT4 and SOX2 are reliable markers in detecting stem cells in odontogenic lesions

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    Abhishek Banerjee

    2016-01-01

    Full Text Available Context (Background: Stem cells are a unique subpopulation of cells in the human body with a capacity to initiate differentiation into various cell lines. Tumor stem cells (TSCs are a unique subpopulation of cells that possess the ability to initiate a neoplasm and sustain self-renewal. Epithelial stem cell (ESC markers such as octamer-binding transcription factor 4 (OCT4 and sex-determining region Y (SRY-box 2 (SOX2 are capable of identifying these stem cells expressed during the early stages of tooth development. Aims: To detect the expression of the stem cell markers OCT4 and SOX2 in the normal odontogenic tissues and the odontogenic cysts and tumors. Materials and Methods: Paraffin sections of follicular tissue, radicular cyst, dentigerous cyst, odontogenic keratocyst, ameloblastoma, adenomatoid odontogenic tumor, and ameloblastic carcinoma were obtained from the archives. The sections were subjected to immunohistochemical assay by the use of mouse monoclonal antibodies to OCT4 and SOX2. Statistical Analysis: The results were evaluated by descriptive analysis. Results: The results show the presence of stem cells in the normal and lesional tissues with these stem cell identifying markers. SOX2 was found to be more consistent and reliable in the detection of stem cells. Conclusion: The stem cell expressions are maintained in the tumor transformation of tissue and probably suggest that there is no phenotypic change of stem cells in progression from normal embryonic state to its tumor component. The quantification and localization reveals interesting trends that indicate the probable role of the cells in the pathogenesis of the lesions.

  9. Detection and clonal analysis of anaerobic bacteria associated to endodontic-periodontal lesions.

    Science.gov (United States)

    Pereira, Cássio V; Stipp, Rafael N; Fonseca, Douglas C; Pereira, Luciano J; Höfling, José F

    2011-12-01

    Microbial agents in root canal systems can induce periodontal inflammation. The aims of this study are to detect anaerobic microorganisms in endodontic-periodontal lesions, determine the genetic diversity among them, and assess the simultaneous colonization of the pulp and periodontal microenvironments by a single clone. Twenty-seven teeth of patients with endodontic-periodontal lesions were selected. Samples were spread on an agar-blood medium, the detection of each species was performed using a polymerase chain reaction, and the determination of the simultaneous presence of the same species in the microenvironments by one or more clones was determined using arbitrarily primed PCR. Prevotella intermedia (Pi) was the most prevalent species of the colonies in periodontal pockets, whereas Porphyromonas gingivalis (Pg) and Pi were the more prevalent in root canals. Isolates of Pi and Pg were simultaneously identified in root canals and periodontal pockets. Eighteen percent of teeth exhibited the simultaneous colonization by Pg, Tannerella forsythia (previously T. forsythensis), and Porphyromonas endodontalis in the pulp and periodontal microenvironments. The presence of these species was noted even in niches from which no colonies were isolated. Seventeen different genotypes were found in periodontal and pulp sites, with the majority of sites colonized by one or two different genotypes. A high degree of genotype similarity was found for samples of Pg isolated from only one site as well as for those isolated from both microenvironments. Different clones of Pi and Pg with a high intraspecific genotype similarity were found to colonize the same anatomic sites in endodontic-periodontal infections.

  10. Characteristic detected on computed tomography angiography predict coronary artery plaque progression in non-culprit lesions

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    Tan, Ya Hang; Zhou, Jia Zhou; Zhou, Ying; Yang, Xiaobo; Yang, Jun Jie; Chen, Yun Dai [Dept. of Cardiology, Chinese PLA General Hospital, Beijing (China)

    2017-06-15

    This study sought to determine whether variables detected on coronary computed tomography angiography (CCTA) would predict plaque progression in non-culprit lesions (NCL). In this single-center trial, we analyzed 103 consecutive patients who were undergoing CCTA and percutaneous coronary intervention (PCI) for culprit lesions. Follow-up CCTA was scheduled 12 months after the PCI, and all patients were followed for 3 years after their second CCTA examination. High-risk plaque features and epicardial adipose tissue (EAT) volume were assessed by CCTA. Each NCL stenosis grade was compared visually between two CCTA scans to detect plaque progression, and patients were stratified into two groups based on this. Logistic regression analysis was used to evaluate the factors that were independently associated with plaque progression in NCLs. Time-to-event curves were compared using the log-rank statistic. Overall, 34 of 103 patients exhibited NCL plaque progression (33%). Logistic regression analyses showed that the NCL progression was associated with a history of ST-elevated myocardial infarction (odds ratio [OR] = 5.855, 95% confidence interval [CI] = 1.391–24.635, p = 0.016), follow-up low-density lipoprotein cholesterol level (OR = 6.832, 95% CI = 2.103–22.200, p = 0.001), baseline low-attenuation plaque (OR = 7.311, 95% CI = 1.242–43.028, p = 0.028) and EAT (OR = 1.015, 95% CI = 1.000–1.029, p = 0.044). Following the second CCTA examination, major adverse cardiac events (MACEs) were observed in 12 patients, and NCL plaque progression was significantly associated with future MACEs (log rank p = 0.006). Noninvasive assessment of NCLs by CCTA has potential prognostic value.

  11. Detection of glass particles on bone lesions using SEM-EDS.

    Science.gov (United States)

    Montoriol, Romain; Guilbeau-Frugier, Céline; Chantalat, Elodie; Roumiguié, Mathieu; Delisle, Marie-Bernadette; Payré, Bruno; Telmon, Norbert; Savall, Frédéric

    2017-09-01

    The problem of identifying the wounding agent in forensic cases is recurrent. Moreover, when several tools are involved, distinguishing the origin of lesions can be difficult. Scanning electron microscopy (SEM)/energy dispersive X-ray analysis (EDS) equipment is increasingly available to the scientific and medical community, and some studies have reported its use in forensic anthropology. However, at our knowledge, no study has reported the use of SEM-EDS in forensic cases involving glass tools, whether in case reports or experiments. We performed an experimental study on human rib fragments, on which we manually created wounds using fragments of window and mirror glass. SEM-EDS was executed on samples without any further preparation on low vacuum mode, then on the same samples after defleshing them completely by boiling them. Window and mirror glass particles were detected on experimental wounds. Both had silica in their spectra, and the opaque side of the mirror contained titanium, allowing for their identification. Boiling and defleshing the bone samples involved a loss of information in terms of the number of wounds detected as positive for glass particles and in the number of glass particles detected, for both window and mirror glass. We suggest the analysis of wounds with suspected glass particles using low vacuum mode and with no defleshment by boiling.

  12. The rate of 99m Tc-MDP uptake in metastatic bone lesions before and after 89m Sr therapy

    International Nuclear Information System (INIS)

    Souza, Joseane Fonseca; Braga, Francisco J.H.N.

    1996-01-01

    The rate of 99m Tc-MDP uptake is studied in metastatic bone lesions, before and after 89m Sr therapy. Eight hopeless patients (age between 56 and 74) presenting disseminated carcinoma of the prostate are evaluated. No hormonal therapy and a limited radiotherapy were considered. It is concluded that therapeutical doses of 89m Sr reduces MDP uptake

  13. Immunohistochemical detection of hTERT in urothelial lesions: a potential adjunct to urine cytology

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    Khalbuss Walid

    2006-08-01

    Full Text Available Abstract Background Urine cytology has a critical role in evaluation for bladder carcinoma. Due to the low sensitivity of this technique, ancillary modalities such as the detection of markers of malignancy by immunochemistry are desirable. Promising factors in this context are components of the human telomerase enzyme complex. Telomerase repairs and extend telomeres, which when eroded beyond a critical limit trigger a senescence checkpoint. Accordingly, while absent in normal somatic cells, telomerase activity has been detected in the great majority of malignant tumor specimens tested, and so has potential value for the recognition of malignant cells in clinical specimens. Methods In this study, we investigated whether the immunohistochemical detection of the catalytic subunit of telomerase (hTERT can aid cytology in the diagnosis of bladder lesions. Findings from the retrospective evaluation of over 100 cell blocks, including urine sediments from confirmed malignant and benign conditions, were compared with routine urine cytology data. Results The presence of hTERT protein was indicative of the transformation of urothelia to a malignant phenotype. Nucleolar hTERT was expressed in 27 (93% of 29 samples obtained from patients with confirmed primary bladder cancer. Conversely, hTERT was detectable in only 3 (0.8% of 39 samples from benign conditions. The hTERT assay showed higher diagnostic sensitivity (84.8% than published urine cytology data (~65% for confirmed bladder carcinoma, however, the hTERT assay was less specific than cytology (65.2% vs. ~95% respectively. Conclusion As a highly sensitive marker, immunohistochemical hTERT detection in urine sediments represents a reliable adjunct to cytology in the accurate diagnosis of urothelial neoplasms.

  14. Predictors of intramedullary lesion expansion rate on MR images of patients with subaxial spinal cord injury.

    Science.gov (United States)

    Le, Elizabeth; Aarabi, Bizhan; Hersh, David S; Shanmuganathan, Kathirkamanthan; Diaz, Cara; Massetti, Jennifer; Akhtar-Danesh, Noori

    2015-06-01

    OBJECT Studies of preclinical spinal cord injury (SCI) in rodents indicate that expansion of intramedullary lesions (IMLs) seen on MR images may be amenable to neuroprotection. In patients with subaxial SCI and motor-complete American Spinal Injury Association (ASIA) Impairment Scale (AIS) Grade A or B, IML expansion has been shown to be approximately 900 μm/hour. In this study, the authors investigated IML expansion in a cohort of patients with subaxial SCI and AIS Grade A, B, C, or D. METHODS Seventy-eight patients who had at least 2 MRI scans within 6 days of SCI were enrolled. Data were analyzed by regression analysis. RESULTS In this cohort, the mean age was 45.3 years (SD 18.3 years), 73 patients were injured in a motor vehicle crash, from a fall, or in sport activities, and 77% of them were men. The mean Injury Severity Score (ISS) was 26.7 (SD 16.7), and the AIS grade was A in 23 patients, B in 7, C in 7, and D in 41. The mechanism of injury was distraction in 26 patients, compression in 22, disc/osteophyte complex in 29, and Chance fracture in 1. The mean time between injury onset and the first MRI scan (Interval 1) was 10 hours (SD 8.7 hours), and the mean time to the second MRI scan (Interval 2) was 60 hours (SD 29.6 hours). The mean IML lengths of the first and second MR images were 38.8 mm (SD 20.4 mm) and 51 mm (SD 36.5 mm), respectively. The mean time from the first to the second MRI scan (Interval 3) was 49.9 hours (SD 28.4 hours), and the difference in IML lengths was 12.6 mm (SD 20.7 mm), reflecting an expansion rate of 366 μm/ hour (SD 710 μm/hour). IML expansion in patients with AIS Grades A and B was 918 μm/hour (SD 828 μm/hour), and for those with AIS Grades C and D, it was 21 μm/hour (SD 304 μm/hour). Univariate analysis indicated that AIS Grade A or B versus Grades C or D (p < 0.0001), traction (p= 0.0005), injury morphology (p < 0.005), the surgical approach (p= 0.009), vertebral artery injury (p= 0.02), age (p < 0.05), ISS (p < 0

  15. Diagnostic sensitivity and interobserver agreement of radiography and ultrasonography for detecting trochlear ridge osteochondrosis lesions in the equine stifle.

    Science.gov (United States)

    Beccati, Francesca; Chalmers, Heather J; Dante, Sara; Lotto, Eleonora; Pepe, Marco

    2013-01-01

    Osteochondrosis lesions commonly occur on the femoral trochlear ridges in horses and radiography and ultrasonography are routinely used to diagnose these lesions. However, poor correlation has been found between radiographic and arthroscopic findings of affected trochlear ridges. Interobserver agreement for ultrasonographic diagnoses and correlation between ultrasonographic and arthroscopic findings have not been previously described. Objectives of this study were to describe diagnostic sensitivity and interobserver agreement of radiography and ultrasonography for detecting and grading osteochondrosis lesions of the equine trochlear ridges, using arthroscopy as the reference standard. Twenty-two horses were sampled. Two observers independently recorded radiographic and ultrasonographic findings without knowledge of arthroscopic findings. Imaging findings were compared between observers and with arthroscopic findings. Agreement between observers was moderate to excellent (κ 0.48-0.86) for detecting lesions using radiography and good to excellent (κ 0.74-0.87) for grading lesions using radiography. Agreement between observers was good to excellent (κ 0.78-0.94) for detecting lesions using ultrasonography and very good to excellent (κ 0.86-0.93) for grading lesions using ultrasonography. Diagnostic sensitivity was 84-88% for radiography and 100% for ultrasonography. Diagnostic specificity was 89-100% for radiography and 60-82% for ultrasonography. Agreement between radiography and arthroscopy was good (κ 0.64-0.78). Agreement between ultrasonography and arthroscopy was very good to excellent (κ 0.81-0.87). Findings from this study support ultrasound as a preferred method for predicting presence and severity of osteochondrosis lesions involving the femoral trochlear ridges in horses. © 2012 Veterinary Radiology & Ultrasound.

  16. Magnetic resonance (MR) colonography in the detection of colorectal lesions: a systematic review of prospective studies

    International Nuclear Information System (INIS)

    Zijta, Frank M.; Bipat, Shandra; Stoker, Jaap

    2010-01-01

    To determine the diagnostic accuracy of MR-colonography for the detection of colorectal lesions. A comprehensive literature search was performed for comparative MR-colonography studies, published between May 1997 and February 2009, using the MEDLINE, EMBASE and Cochrane databases. We included studies if MR-colonography findings were prospectively compared with conventional colonoscopy in (a)symptomatic patients. Two reviewers independently extracted study design characteristics and data for summarising sensitivity and specificity. Heterogeneity in findings between studies was tested using I 2 test statistics. Sensitivity and specificity estimates with 95% confidence intervals (CI) were calculated on per patient basis and summary sensitivity on per polyp basis, using bivariate and univariate statistical models. Thirty-seven studies were found to be potentially relevant and 13 fulfilled the inclusion criteria. The study population comprised 1,285 patients with a mean disease prevalence of 44% (range 22-63%). Sensitivity for the detection of CRC was 100%. Significant heterogeneity was found for overall per patient sensitivity and specificity. For polyps with a size of 10 mm or larger, per patient sensitivity and specificity estimates were 88% (95% CI 63-97%; I 2 = 37%) and 99% (95% CI 95-100%; I 2 = 60%). On a per polyp basis, polyps of 10 mm or larger were detected with a sensitivity of 84% (95% CI 66-94%; I 2 = 51%). The data were too heterogeneous for polyps smaller than 6 mm and 6-9 mm. MR-colonography can accurately detect colorectal polyps more than 10 mm in size. (orig.)

  17. Noninvasive detection of macrophages in atherosclerotic lesions by computed tomography enhanced with PEGylated gold nanoparticles

    Directory of Open Access Journals (Sweden)

    Qin J

    2014-12-01

    Full Text Available Jinbao Qin,1,* Chen Peng,2,* Binghui Zhao,2,* Kaichuang Ye,1 Fukang Yuan,1 Zhiyou Peng,1 Xinrui Yang,1 Lijia Huang,1 Mier Jiang,1 Qinghua Zhao,3 Guangyu Tang,2 Xinwu Lu1,4 1Department of Vascular Surgery, Shanghai Ninth People’s Hospital Affiliated to Shanghai JiaoTong University, School of Medicine; 2Department of Radiology, Shanghai Tenth People’s Hospital Affiliated to Tongji University, School of Medicine; 3Department of Orthopaedics, Shanghai First People’s Hospital, School of Medicine, Shanghai Jiao Tong University; 4Vascular Center of Shanghai JiaoTong University, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: Macrophages are becoming increasingly significant in the progression of atherosclerosis (AS. Molecular imaging of macrophages may improve the detection and characterization of AS. In this study, dendrimer-entrapped gold nanoparticles (Au DENPs with polyethylene glycol (PEG and fluorescein isothiocyanate (FI coatings were designed, tested, and applied as contrast agents for the enhanced computed tomography (CT imaging of macrophages in atherosclerotic lesions. Cell counting kit-8 assay, fluorescence microscopy, silver staining, and transmission electron microscopy revealed that the FI-functionalized Au DENPs are noncytotoxic at high concentrations (3.0 µM and can be efficiently taken up by murine macrophages in vitro. These nanoparticles were administered to apolipoprotein E knockout mice as AS models, which demonstrated that the macrophage burden in atherosclerotic areas can be tracked noninvasively and dynamically three-dimensionally in live animals using micro-CT. Our findings suggest that the designed PEGylated gold nanoparticles are promising biocompatible nanoprobes for the CT imaging of macrophages in atherosclerotic lesions and will provide new insights into the pathophysiology of AS and other concerned inflammatory diseases. Keywords: atherosclerosis, CT, in vivo

  18. DETECTION OF OXIDATIVE STRESS, APOPTOSIS AND MOLECULAR LESIONS IN HUMAN OVARIAN CANCER CELLS

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    H. I. Falfushynska

    2016-05-01

    Full Text Available Background. Ovarian cancer has the highest mortality rate of gynaecological cancers. This is partly due to the lack of effective screening markers. Indices of oxidative stress are well-recognized prognostic criteria for tumorous transformation of tissue, but their value depends on the type of tumor and the stage of its development. Objective. The aim of this study is to clarify the relationship between antioxidant/pro-oxidant ratio and the signs of molecular lesions and apoptosis rate in blood of ovarian cancer patients and non-cancer ones. Results. The ovarian cancer group is marked by antioxidant/prooxidant balance shifting to oxidative damage in blood as the consequence of overexpression of oxyradicals (by 300%. Higher level of glutathione (by 366%, lower level of metallothioneins (by 65% as well as higher level of lipid peroxidation (by 174% and protein carbonyls (by 186% in blood of ovarian cancer patients compared to the normal ovarian group have been observed. The signs of cytotoxicity are determined in blood of ovarian cancer patients: an increased (compared to control level of DNA fragmentation (by 160%, choline esterase (up to twice, higher rate of both caspase dependent and caspase independent lysosomal mediated apoptosis. Conclusions. Cathepsin D activity both total and free, choline esterase activity, TBA-reactive substance and protein carbonyls level in blood could be used as the predictive markers of worse prognosis and the signs of human ovarian cancer.

  19. Comparison of conventional panoramic radiography and panoramic digital subtraction radiography in detection of simulated lesions of mandibular condyle

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    Panjnoush M.

    2008-12-01

    Full Text Available "n  "nBackground and Aim: Digital subtraction Radiography (DSR is a method of accurate assessing condylar head changes. several studies have been carried out in applying DSR in dentistry, however there is a few number of studies in efficacy of DSR method in assesment of condylar head changes, The aim of this study was to compare panoramic radiography and DSR detecting simulated lesions of the mandibular condyl. "nMaterials and Methods: this was a process reaserch study, in which two dry human skulls with no obvious temporomandibular joint pathology were used. Osteophytic lesions were simulated using three sizes of bone chips that were placed on the medial portion of anterior and superolateral aspects of the condyle. Osteolytic lesions were simulated making 1 and 2 mm holes using round burr in the central portion of anterior aspect and Lateral pole of the condyle. Panoramic radiographs were prepared with and without the lesions in place. These paired radiographs were digitized and digital- subtraction images of the original panoramic images were obtained. Eight observers evaluated 155 images of each modality for the presence or absence and the type of simulated lesions of the mandibular condyle. Sensitivity, specificity, reliability and measure of agreement were analyzed using kappa test and crossed tables and qualitative variables were assess by chi-square and fisher's Exact test. "nResults: Specificity of panoramic and DSR methods were 15.4% and 66.7% respectively. Sensitivity of panoramic and DSR methods were 61.1% and 80.6% for osteophytic lesions and 37.5% and 83.3% for Osteolytic lesions. The percentage of correct decisions made in DSR method was significantly more than conventional panoramic method (82.6% vs 41.9% (p<0.0001. "nConclusion: Based on the results of this study digital subtraction technique was significantly more accurate than the panoramic radiographs in detection of simulated lesions of the mandibular condyle.

  20. Detection and excision of non-palpable breast lesions by radio guided surgery and air injection for radiological control

    International Nuclear Information System (INIS)

    Machado, Rafael Henrique Szymanski; Gutfilen, Bianca; Fonseca, Lea Mirian Barbosa da

    2005-01-01

    Purpose: to asses the efficiency of the radioguided localization and removal of occult breast lesions using radiopharmaceuticals injected directly into the lesions or close to them with posterior air injection as a radiological control. Methods: twenty-nine consecutive patients with thirty-two occult breast lesions detected mammographically or by ultrasound, and categorized 3, 4 and 5 BI-RADS, were included in this observational study with results expressed in percentages. The radiopharmaceutical used was human serum albumin labeled with 99m Tc-HSA injected inside or close to the lesion using mammographic or ultrasonographic guidance. The injection of the radiopharmaceutical was followed immediately by air injection through the needle used for stereotaxis as a radiological control of the radiopharmaceutical placement. The excision biopsy was carried out with the aid of a hand-held gamma-detecting probe and the entire removal of the lesion was verified by X-ray of the surgical specimens or by intraoperative frozen section examination. Results: breast cancer was found in 10.0% (1/10) of the 3 BI-RADS lesions, in 31.5% (6/19) of the 4 BI-RADS and in 66.6% (2/3) of the 5 BI-RADS. The radiotracer was correctly positioned in 96.8% of the specimens (31/32) allowing the removal of also 96.8% of the studied non-palpable breast lesions. To show the entire removal, X-ray was used in 23 cases (71.8%), intraoperative frozen section study in 21.8% (7/32) and both methods in 6.2% (2/32). Conclusions: radioguided surgery showed to be an important tool in the removal of non-palpable breast lesions, as a simple, fast and feasible method that can be implemented in the clinical routine of these patients. (author)

  1. Detection of exudates in fundus imagery using a constant false-alarm rate (CFAR) detector

    Science.gov (United States)

    Khanna, Manish; Kapoor, Elina

    2014-05-01

    Diabetic retinopathy is the leading cause of blindness in adults in the United States. The presence of exudates in fundus imagery is the early sign of diabetic retinopathy so detection of these lesions is essential in preventing further ocular damage. In this paper we present a novel technique to automatically detect exudates in fundus imagery that is robust against spatial and temporal variations of background noise. The detection threshold is adjusted dynamically, based on the local noise statics around the pixel under test in order to maintain a pre-determined, constant false alarm rate (CFAR). The CFAR detector is often used to detect bright targets in radar imagery where the background clutter can vary considerably from scene to scene and with angle to the scene. Similarly, the CFAR detector addresses the challenge of detecting exudate lesions in RGB and multispectral fundus imagery where the background clutter often exhibits variations in brightness and texture. These variations present a challenge to common, global thresholding detection algorithms and other methods. Performance of the CFAR algorithm is tested against a publicly available, annotated, diabetic retinopathy database and preliminary testing suggests that performance of the CFAR detector proves to be superior to techniques such as Otsu thresholding.

  2. [Accuracy of computer aided measurement for detecting dental proximal caries lesions in images of cone-beam computed tomography].

    Science.gov (United States)

    Zhang, Z L; Li, J P; Li, G; Ma, X C

    2017-02-09

    Objective: To establish and validate a computer program used to aid the detection of dental proximal caries in the images cone beam computed tomography (CBCT) images. Methods: According to the characteristics of caries lesions in X-ray images, a computer aided detection program for proximal caries was established with Matlab and Visual C++. The whole process for caries lesion detection included image import and preprocessing, measuring average gray value of air area, choosing region of interest and calculating gray value, defining the caries areas. The program was used to examine 90 proximal surfaces from 45 extracted human teeth collected from Peking University School and Hospital of Stomatology. The teeth were then scanned with a CBCT scanner (Promax 3D). The proximal surfaces of the teeth were respectively detected by caries detection program and scored by human observer for the extent of lesions with 6-level-scale. With histologic examination serving as the reference standard, the caries detection program and the human observer performances were assessed with receiver operating characteristic (ROC) curves. Student t -test was used to analyze the areas under the ROC curves (AUC) for the differences between caries detection program and human observer. Spearman correlation coefficient was used to analyze the detection accuracy of caries depth. Results: For the diagnosis of proximal caries in CBCT images, the AUC values of human observers and caries detection program were 0.632 and 0.703, respectively. There was a statistically significant difference between the AUC values ( P= 0.023). The correlation between program performance and gold standard (correlation coefficient r (s)=0.525) was higher than that of observer performance and gold standard ( r (s)=0.457) and there was a statistically significant difference between the correlation coefficients ( P= 0.000). Conclusions: The program that automatically detects dental proximal caries lesions could improve the

  3. Assessment of enamel-dentin caries lesions detection using bitewing PSP digital images

    Directory of Open Access Journals (Sweden)

    Marianna Guanaes Gomes Torres

    2011-10-01

    Full Text Available 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.

  4. A COMPARATIVE ANALYSIS OF SINGLE AND COMBINATION FEATURE EXTRACTION TECHNIQUES FOR DETECTING CERVICAL CANCER LESIONS

    Directory of Open Access Journals (Sweden)

    S. Pradeep Kumar Kenny

    2016-02-01

    Full Text Available Cervical cancer is the third most common form of cancer affecting women especially in third world countries. The predominant reason for such alarming rate of death is primarily due to lack of awareness and proper health care. As they say, prevention is better than cure, a better strategy has to be put in place to screen a large number of women so that an early diagnosis can help in saving their lives. One such strategy is to implement an automated system. For an automated system to function properly a proper set of features have to be extracted so that the cancer cell can be detected efficiently. In this paper we compare the performances of detecting a cancer cell using a single feature versus a combination feature set technique to see which will suit the automated system in terms of higher detection rate. For this each cell is segmented using multiscale morphological watershed segmentation technique and a series of features are extracted. This process is performed on 967 images and the data extracted is subjected to data mining techniques to determine which feature is best for which stage of cancer. The results thus obtained clearly show a higher percentage of success for combination feature set with 100% accurate detection rate.

  5. Model observer for assessing digital breast tomosynthesis for multi-lesion detection in the presence of anatomical noise

    Science.gov (United States)

    Wen, Gezheng; Markey, Mia K.; Miner Haygood, Tamara; Park, Subok

    2018-02-01

    Model observers are widely used in task-based assessments of medical image quality. The presence of multiple abnormalities in a single set of images, such as in multifocal multicentric breast cancer (MFMC), has an immense clinical impact on treatment planning and survival outcomes. Detecting multiple breast tumors is challenging as MFMC is relatively uncommon, and human observers do not know the number or locations of tumors a priori. Digital breast tomosynthesis (DBT), in which an x-ray beam sweeps over a limited angular range across the breast, has the potential to improve the detection of multiple tumors. However, prior studies of DBT image quality all focus on unifocal breast cancers. In this study, we extended our 2D multi-lesion (ML) channelized Hotelling observer (CHO) into a 3D ML-CHO that detects multiple lesions from volumetric imaging data. Then we employed the 3D ML-CHO to identify optimal DBT acquisition geometries for detection of MFMC. Digital breast phantoms with multiple embedded synthetic lesions were scanned by simulated DBT scanners of different geometries (wide/narrow angular span, different number of projections per scan) to simulate MFMC cases. With new implementations of 3D partial least squares (PLS) and modified Laguerre-Gauss (LG) channels, the 3D ML-CHO made detection decisions based upon the overall information from individual DBT slices and their correlations. Our evaluation results show that: (1) the 3D ML-CHO could achieve good detection performance with a small number of channels, and 3D PLS channels on average outperform the counterpart LG channels; (2) incorporating locally varying anatomical backgrounds and their correlations as in the 3D ML-CHO is essential for multi-lesion detection; (3) the most effective DBT geometry for detection of MFMC may vary when the task of clinical interest changes, and a given DBT geometry may not yield images that are equally informative for detecting MF, MC, and unifocal cancers.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    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. (paper)

  7. Continuously moving table MRI with sliding multislice for rectal cancer staging: Image quality and lesion detection

    International Nuclear Information System (INIS)

    Baumann, Tobias; Ludwig, Ute; Pache, Gregor; Fautz, Hans-Peter; Kotter, Elmar; Langer, Mathias; Schaefer, Oliver

    2010-01-01

    Purpose: To determine image quality and lesion detection of sliding multislice (SMS), a recently developed moving table MRI technique, in patients with rectal cancer. Materials and methods: Twenty-seven paired SMS (Avanto, Siemens Medical Solutions) and MDCT (Sensation 64, Siemens Medical Solutions) examinations of abdomen and pelvis were performed in patients with rectal cancer and compared for detection of liver, lymph node and bone metastases by two independent observers. A contrast-enhanced, fat saturated 2D gradient echo sequence (TE, 2.0 ms; TR, 102 ms; slice, 5 mm) was acquired with SMS and a standard contrast-enhanced protocol (100 ml 2.5 ml/s; slice, 5 mm) was used for abdominal MDCT. Standard of reference consisted of a consensus evaluation of SMS, MDCT, and all available follow-up examinations after a period of 6 months. Artifact burden and image quality of SMS was assessed in comparison to stationary gradient echo sequences obtained in an age-matched group of 27 patients. Results: Whereas SMS achieved a mean quality score of 3.65 (scale, 0-4) for the liver, representing very good diagnostic properties, strong breathing artifacts in the intestinal region were observed in 19 cases by both observers. The retroperitoneum still achieved a mean quality score of 3.52, although breathing artifacts were noted in 12 and 15 cases (observers 1 and 2, respectively). The sensitivities of SMS to detect hepatic metastases were 91.2% and 94.1% for both observers, respectively, compared to 98.5%/98.5% for MDCT. The sensitivities for lymph node metastases were 87.5%/81.3% for SMS compared to 78.1%/81.3% for MDCT. The sensitivities for bone metastases were 91.7%/100% for SMS compared to 8.3%/16.7% for MDCT. Conclusion: With slightly reduced image quality in the intestinal region, SMS exhibits equal detection of lymph node and liver metastases compared to MDCT. SMS MRI proved to be superior to MDCT in detection of bone metastases.

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

    Science.gov (United States)

    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.

  9. Probability of detection of clinical seizures using heart rate changes.

    Science.gov (United States)

    Osorio, Ivan; Manly, B F J

    2015-08-01

    Heart rate-based seizure detection is a viable complement or alternative to ECoG/EEG. This study investigates the role of various biological factors on the probability of clinical seizure detection using heart rate. Regression models were applied to 266 clinical seizures recorded from 72 subjects to investigate if factors such as age, gender, years with epilepsy, etiology, seizure site origin, seizure class, and data collection centers, among others, shape the probability of EKG-based seizure detection. Clinical seizure detection probability based on heart rate changes, is significantly (pprobability of detecting clinical seizures (>0.8 in the majority of subjects) using heart rate is highest for complex partial seizures, increases with a patient's years with epilepsy, is lower for females than for males and is unrelated to the side of hemisphere origin. Clinical seizure detection probability using heart rate is multi-factorially dependent and sufficiently high (>0.8) in most cases to be clinically useful. Knowledge of the role that these factors play in shaping said probability will enhance its applicability and usefulness. Heart rate is a reliable and practical signal for extra-cerebral detection of clinical seizures originating from or spreading to central autonomic network structures. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  10. Extirpation of a cranial lesion radio guided by scintigraphy and intraoperative detection

    International Nuclear Information System (INIS)

    Concha Julio, Enrique; Basuri, Luciano; Otayza, Felipe; Neubauer, Sonia; Mena, Ismael; Arteaga, Maria Paz

    2005-01-01

    A skull lesion may be difficult to localize, specially a small one that is not evident on the external surface. In this paper, we describe the localization and extirpation aided by intraoperative radio guidance of a 2 cm lesion compromising the internal aspect of the posterior temporal bone. The radiological expression of this lesion was poor, both on the plain radiograph's and on the computed tomography, making the intraoperative radiology and the navigation aided by computed tomography useless. The lesion was extirpated in block and the skull repaired. The biopsy confirmed a Paget's disease. There were not surgical complications (au)

  11. Arduino-based noise robust online heart-rate detection.

    Science.gov (United States)

    Das, Sangita; Pal, Saurabh; Mitra, Madhuchhanda

    2017-04-01

    This paper introduces a noise robust real time heart rate detection system from electrocardiogram (ECG) data. An online data acquisition system is developed to collect ECG signals from human subjects. Heart rate is detected using window-based autocorrelation peak localisation technique. A low-cost Arduino UNO board is used to implement the complete automated process. The performance of the system is compared with PC-based heart rate detection technique. Accuracy of the system is validated through simulated noisy ECG data with various levels of signal to noise ratio (SNR). The mean percentage error of detected heart rate is found to be 0.72% for the noisy database with five different noise levels.

  12. The performance of multimodal hyperspectral spectroscopy in the detection of precancerous cervical lesions

    Science.gov (United States)

    Trahmono; Lusiana, N.; Indarti, J.

    2017-08-01

    The aim of this study was to compare the performance of multimodal hyperspectral spectroscopy (MHS), which combines fluorescence and reflectance spectroscopy, with that of conventional laboratory-based screening tests, such as the Papanicolaou (Pap) smear test and human papilloma virus (HPV) DNA test, for detecting precancerous lesions of the cervix. The study utilized a cross-sectional design, and the kappa test was used in the analytical assessment. MHS scans were obtained from a sample of 70 consecutive patients, followed by sample collection for Pap and HPV DNA analysis and colposcopy referral, if indicated. Of the 70 patients evaluated, the results of cervical spectroscopy were normal in 38 (54.3%) patients, and they were abnormal in 32 (45.7%) patients. Based on the cytology results, 45 (64.3%) samples were normal, and 25 (35.7%) samples were abnormal. According to the results of the HPV DNA test, 47 (67.14%) samples were normal, and 17 (24.28%) samples were abnormal. Based on the results of the kappa test, the agreement between MHS and cytology was 0.793 (p < 0.001). The agreement between MHS and the HPV DNA test was 0.195 (p = 0.086), and the agreement between MHS and colposcopy was 0.479 (p < 0.001).

  13. Quantification, improvement, and harmonization of small lesion detection with state-of-the-art PET

    Energy Technology Data Exchange (ETDEWEB)

    Vos, Charlotte S. van der [Radboud University Medical Centre, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); University of Twente, MIRA Institute for Biomedical Technology and Technical Medicine, Enschede (Netherlands); Koopman, Danielle [University of Twente, MIRA Institute for Biomedical Technology and Technical Medicine, Enschede (Netherlands); Isala Hospital, Department of Nuclear Medicine, Zwolle (Netherlands); Rijnsdorp, Sjoerd; Arends, Albert J. [Catharina Hospital, Department of Medical Physics, Eindhoven (Netherlands); Boellaard, Ronald [University of Groningen, University Medical Centre Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); VU University Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Dalen, Jorn A. van [Isala Hospital, Department of Nuclear Medicine, Zwolle (Netherlands); Isala, Department of Medical Physics, Zwolle (Netherlands); Lubberink, Mark [Uppsala University, Department of Surgical Sciences, Uppsala (Sweden); Uppsala University Hospital, Department of Medical Physics, Uppsala (Sweden); Willemsen, Antoon T.M. [University of Groningen, University Medical Centre Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); Visser, Eric P. [Radboud University Medical Centre, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands)

    2017-08-15

    In recent years, there have been multiple advances in positron emission tomography/computed tomography (PET/CT) that improve cancer imaging. The present generation of PET/CT scanners introduces new hardware, software, and acquisition methods. This review describes these new developments, which include time-of-flight (TOF), point-spread-function (PSF), maximum-a-posteriori (MAP) based reconstruction, smaller voxels, respiratory gating, metal artefact reduction, and administration of quadratic weight-dependent {sup 18}F-fluorodeoxyglucose (FDG) activity. Also, hardware developments such as continuous bed motion (CBM), (digital) solid-state photodetectors and combined PET and magnetic resonance (MR) systems are explained. These novel techniques have a significant impact on cancer imaging, as they result in better image quality, improved small lesion detectability, and more accurate quantification of radiopharmaceutical uptake. This influences cancer diagnosis and staging, as well as therapy response monitoring and radiotherapy planning. Finally, the possible impact of these developments on the European Association of Nuclear Medicine (EANM) guidelines and EANM Research Ltd. (EARL) accreditation for FDG-PET/CT tumor imaging is discussed. (orig.)

  14. Bond strength to dentin with artificial carious lesions: influence of caries detecting dye.

    Science.gov (United States)

    Palma, R G; Turbino, M L; Matson, E; Powers, J M

    1998-06-01

    To evaluate the influence of dyes for caries detection on tensile bond strength of adhesive materials to artificial carious dentin. Buccal and lingual enamel of human molars were removed leaving intact dentin surfaces. The entire surface of each specimen was covered with nail varnish, keeping a window area of 4 x 4 mm. Artificial carious lesions were induced with acidified gel. Three dyes (0.5% basic fuchsin; Caries Finder and Cari-D-Tect) were used according to manufacturers' recommendations. Specimens were etched with 35% phosphoric acid for 20 s, washed and dried, leaving a wet dentin surface. The adhesive system (Prime & Bond 2.0) was applied in two layers and light-cured. Restorative materials (TPH Spectrum, Dyract, Advance) were bonded using a 3-mm diameter inverted-cone mold. Control groups were made without dye. Eight samples were tested for each group. After 24 hrs of storage in distilled water, the samples were debonded using a testing machine at 0.5 mm/min crosshead speed. ANOVA and Tukey-Kramer test showed that TPH Spectrum (0.73 MPa) and Dyract (0.74 MPa) had similar bond strengths, and both were higher than Advance (0.0 MPa), which was statistically different (P strength for any tested materials.

  15. Quantification, improvement, and harmonization of small lesion detection with state-of-the-art PET

    International Nuclear Information System (INIS)

    Vos, Charlotte S. van der; Koopman, Danielle; Rijnsdorp, Sjoerd; Arends, Albert J.; Boellaard, Ronald; Dalen, Jorn A. van; Lubberink, Mark; Willemsen, Antoon T.M.; Visser, Eric P.

    2017-01-01

    In recent years, there have been multiple advances in positron emission tomography/computed tomography (PET/CT) that improve cancer imaging. The present generation of PET/CT scanners introduces new hardware, software, and acquisition methods. This review describes these new developments, which include time-of-flight (TOF), point-spread-function (PSF), maximum-a-posteriori (MAP) based reconstruction, smaller voxels, respiratory gating, metal artefact reduction, and administration of quadratic weight-dependent 18 F-fluorodeoxyglucose (FDG) activity. Also, hardware developments such as continuous bed motion (CBM), (digital) solid-state photodetectors and combined PET and magnetic resonance (MR) systems are explained. These novel techniques have a significant impact on cancer imaging, as they result in better image quality, improved small lesion detectability, and more accurate quantification of radiopharmaceutical uptake. This influences cancer diagnosis and staging, as well as therapy response monitoring and radiotherapy planning. Finally, the possible impact of these developments on the European Association of Nuclear Medicine (EANM) guidelines and EANM Research Ltd. (EARL) accreditation for FDG-PET/CT tumor imaging is discussed. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Asmitananda Thakur

    2012-01-01

    Full Text Available 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.

  17. Tissue resonance interaction accurately detects colon lesions: A double-blind pilot study.

    Science.gov (United States)

    Dore, Maria P; Tufano, Marcello O; Pes, Giovanni M; Cuccu, Marianna; Farina, Valentina; Manca, Alessandra; Graham, David Y

    2015-07-07

    To investigated the performance of the tissue resonance interaction method (TRIM) for the non-invasive detection of colon lesions. 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 χ(2) test. 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 negative predictive

  18. Inter- and intraobserver variability of MR arthrography in the detection and classification of superior labral anterior posterior (SLAP) lesions: evaluation in 78 cases with arthroscopic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Holzapfel, Konstantin; Waldt, Simone; Bruegel, Melanie; Rummeny, Ernst J.; Woertler, Klaus [Technische Universitaet Muenchen, Department of Radiology, Klinikum rechts der Isar, Munich (Germany); Paul, Jochen; Imhoff, Andreas B. [Technische Universitaet Muenchen, Department of Sports Orthopedics, Klinikum rechts der Isar, Munich (Germany); Heinrich, Petra [Technische Universitaet Muenchen, Institute of Medical Statistics and Epidemiology, Klinikum rechts der Isar, Munich (Germany)

    2010-03-15

    The purpose of this study was to determine inter- and intraobserver variability of MR arthrography of the shoulder in the detection and classification of superior labral anterior posterior (SLAP) lesions. MR arthrograms of 78 patients who underwent MR arthrography before arthroscopy were retrospectively analysed by three blinded readers for the presence and type of SLAP lesions. MR arthrograms were reviewed twice by each reader with a time interval of 4 months between the two readings. Inter- and intraobserver agreement for detection and classification of SLAP lesions were calculated using {kappa} coefficients. Arthroscopy confirmed 48 SLAP lesions: type I (n = 4), type II (n = 37), type III (n = 3), type IV (n = 4). Sensitivity and specificity for detecting SLAP lesions with MR arthrography for each reader were 88.6%/93.3%, 90.9%/80.0% and 86.4%/76.7%. MR arthrographic and arthroscopic grading were concurrent for 72.7%, 68.2% and 70.5% of SLAP lesions for readers 1-3, respectively. Interobserver agreement was excellent ({kappa} = 0.82) for detection and substantial ({kappa} = 0.63) for classification of SLAP lesions. For each reader intraobserver agreement was excellent for detection ({kappa} = 0.93, {kappa} = 0.97, {kappa} = 0.97) and classification ({kappa} = 0.94, {kappa} = 0.84, {kappa} = 0.93) of SLAP lesions. MR arthrography allows reliable and accurate detection of SLAP lesions. In addition, SLAP lesions can be diagnosed and classified with substantial to excellent inter- and intraobserver agreement. (orig.)

  19. Inter- and intraobserver variability of MR arthrography in the detection and classification of superior labral anterior posterior (SLAP) lesions: evaluation in 78 cases with arthroscopic correlation

    International Nuclear Information System (INIS)

    Holzapfel, Konstantin; Waldt, Simone; Bruegel, Melanie; Rummeny, Ernst J.; Woertler, Klaus; Paul, Jochen; Imhoff, Andreas B.; Heinrich, Petra

    2010-01-01

    The purpose of this study was to determine inter- and intraobserver variability of MR arthrography of the shoulder in the detection and classification of superior labral anterior posterior (SLAP) lesions. MR arthrograms of 78 patients who underwent MR arthrography before arthroscopy were retrospectively analysed by three blinded readers for the presence and type of SLAP lesions. MR arthrograms were reviewed twice by each reader with a time interval of 4 months between the two readings. Inter- and intraobserver agreement for detection and classification of SLAP lesions were calculated using κ coefficients. Arthroscopy confirmed 48 SLAP lesions: type I (n = 4), type II (n = 37), type III (n = 3), type IV (n = 4). Sensitivity and specificity for detecting SLAP lesions with MR arthrography for each reader were 88.6%/93.3%, 90.9%/80.0% and 86.4%/76.7%. MR arthrographic and arthroscopic grading were concurrent for 72.7%, 68.2% and 70.5% of SLAP lesions for readers 1-3, respectively. Interobserver agreement was excellent (κ = 0.82) for detection and substantial (κ = 0.63) for classification of SLAP lesions. For each reader intraobserver agreement was excellent for detection (κ = 0.93, κ = 0.97, κ = 0.97) and classification (κ = 0.94, κ = 0.84, κ = 0.93) of SLAP lesions. MR arthrography allows reliable and accurate detection of SLAP lesions. In addition, SLAP lesions can be diagnosed and classified with substantial to excellent inter- and intraobserver agreement. (orig.)

  20. Image-guided automated needle biopsy of 106 thoracic lesions: a retrospective review of diagnostic accuracy and complication rates

    International Nuclear Information System (INIS)

    Connor, S.; Dyer, J.; Guest, P.

    2000-01-01

    We reviewed the diagnostic accuracy and complication rates of transthoracic needle biopsy (TNB) with an automated 18-gauge core biopsy needle and gun, using either fluoroscopic or CT guidance. One hundred six lesions were biopsied in 103 patients between 1992 and 1998. Hard-copy images, imaging reports, pathology reports and clinical notes were reviewed. In 3 patients it was not possible to establish the lesion as either malignant or benign from the available follow-up, so these were removed from the analysis of diagnostic accuracy. Adequate samples for histological diagnosis were obtained in 104 of 106 (98 %) biopsies. There were 75 of 85 (88 %) true-positive core biopsies for malignant lesions and a specific cell type was identified in 70 of 85 (82 %) cases. A specific histological diagnosis was obtained in 12 of 18 (66 %) biopsies. There was a 19 % rate of pneumothorax with only 2.4 % requiring drainage. Minor haemoptysis occurred in 3.8 % of procedures. The TNB technique with an automated core biopsy needle provides a high level of diagnostic accuracy, effectively distinguishes cell type in malignancy and provides a definite diagnosis in benign disease more frequently than fine needle aspiration (FNA). There is no increased complication rate compared with FNA. (orig.)

  1. Wallerian degeneration of the corticodescending tract in the cerebral peduncle following a supratentorial cerebrovascular lesion detected by MRI

    International Nuclear Information System (INIS)

    Waragai, Masaaki; Iwabuchi, Sadamu

    1993-01-01

    We studied Wallerian degeneration of the corticodescending tract in the cerebral peduncle following a supratentorial cerebrovascular lesion by MRI. A total of 57 patients with palsy following a supratenotorial cerebrovascular lesion were prospectively studied. Wallerian degeneration was detected as a high signal intensity (HSI) in 37 patients between 70 days and 100 days after the onset, but not detected in the remaining 27 patients. Patient with as HSI in all areas of the cerebral peduncle had a large lesion involving the hemisphere. Patient with an HSI at the center of the cerebral peduncle had a lesion confined to the paracentral gyrus, precentral gyrus, corona radiata or posterior limb of the internal capsule. Patient with an HSI at the lateral side of the cerebral peduncle had a lesion of parietal lobe or temporal lobe which spares the corticospinal tract originating from the paracentral gyrus, precentral gyrus, corona radiata or posterior limb of the internal capsule. These findings suggest that as HSI at the center of the cerebral peduncle may reveal Wallerian degeneration of the corticospinal tract, and an HSI at the lateral side of the cerebral peduncle may show Wallerian degeneration of the corticopontine tract. The functional recovery of paresis was poor in all patients with an HSI at the center of the cerebral peduncle, while it was good in all patients without an HSI in that region. Our data suggested that somatotopical localization of the corticodescending tract in the cerebral peduncle may be identified by detecting Wallerian degeneration following a supratentorial lesion, and the functional recovery of patients with paresis could be predicted according to presence or absence of Wallerian degeneration at the center of the cerebral peduncle. (author)

  2. Detection of infarct lesions from single MRI modality using inconsistency between voxel intensity and spatial location--a 3-D automatic approach.

    Science.gov (United States)

    Shen, Shan; Szameitat, André J; Sterr, Annette

    2008-07-01

    Detection of infarct lesions using traditional segmentation methods is always problematic due to intensity similarity between lesions and normal tissues, so that multispectral MRI modalities were often employed for this purpose. However, the high costs of MRI scan and the severity of patient conditions restrict the collection of multiple images. Therefore, in this paper, a new 3-D automatic lesion detection approach was proposed, which required only a single type of anatomical MRI scan. It was developed on a theory that, when lesions were present, the voxel-intensity-based segmentation and the spatial-location-based tissue distribution should be inconsistent in the regions of lesions. The degree of this inconsistency was calculated, which indicated the likelihood of tissue abnormality. Lesions were identified when the inconsistency exceeded a defined threshold. In this approach, the intensity-based segmentation was implemented by the conventional fuzzy c-mean (FCM) algorithm, while the spatial location of tissues was provided by prior tissue probability maps. The use of simulated MRI lesions allowed us to quantitatively evaluate the performance of the proposed method, as the size and location of lesions were prespecified. The results showed that our method effectively detected lesions with 40-80% signal reduction compared to normal tissues (similarity index > 0.7). The capability of the proposed method in practice was also demonstrated on real infarct lesions from 15 stroke patients, where the lesions detected were in broad agreement with true lesions. Furthermore, a comparison to a statistical segmentation approach presented in the literature suggested that our 3-D lesion detection approach was more reliable. Future work will focus on adapting the current method to multiple sclerosis lesion detection.

  3. Molecular detection of bacteria associated to caries activity in dentinal lesions.

    Science.gov (United States)

    Neves, Beatriz Gonçalves; Stipp, Rafael Nóbrega; da Silva Bezerra, Daniela; de Figueiredo Guedes, Sarah Florindo; Rodrigues, Lidiany Karla Azevedo

    2017-07-01

    This study aimed at identifying and quantifying Actinomyces naeslundii, Bifidobacterium spp., Streptococcus mitis group, Lactobacillus acidophilus, Lactobacillus casei group, Streptococcus gordonii, and Streptococcus mutans in active and inactive carious dentine lesions of children with early childhood caries by using quantitative polymerase chain reaction. Fifty-six dentin lesion samples, classified as active (n = 39) or inactive (n = 17), were collected from children aged from 2 to 5 years old. Dentinal-cavitated lesions were evaluated by Nyvad criteria for the assessment of caries lesion activity. Relative quantification revealed that Bifidobacterium spp. and the L. casei group were significantly more abundant in active dentin lesions (p oral microbiota related to dentin caries activity status is relevant, this study provides insights to better understand the differences in the microbiotas between active and arrested dentin cavities.

  4. Is 3D MPRAGE better than the combination DIR/PSIR for cortical lesion detection at 3T MRI?

    Science.gov (United States)

    Nelson, Flavia; Poonawalla, Aziz; Datta, Sushmita; Wolinsky, Jerry; Narayana, Ponnada

    2014-03-01

    Based on the application of newer magnetic resonance imaging (MRI) acquisition sequences, the detection of cortical lesions (CL) in multiple sclerosis (MS) has significantly improved. Double inversion recovery (DIR) at 3T has increased the detection sensitivity and classification specificity when combined with phase sensitive inversion recovery (PSIR). Previous findings with 3D magnetization prepared rapid acquisition with gradient echo (MPRAGE) sequences, showed improved classification specificity of purely intracortical (IC) and mixed (MX) lesions, compared to the classification based on DIR/PSIR. Direct comparison between the detection of CL by 3D MPRAGE and by DIR/PSIR at 3T has not been evaluated. Eleven subjects were imaged on a 3T magnet. DIR/PSIR and 3D MPRAGE images were reviewed independently. Each image set was reviewed twice; only lesions detected on both sessions were scored. Review time per scan was ~5min for DIR/PSIR and ~15min for 3D MPRAGE. We identified 141 CL (62 IC+79 MX) based on DIR/PSIR images vs. 93 (38 IC+55 MX) based on MPRAGE from all eleven patients. MPRAGE under-detected the number of CL in seven cases and over-detected the number of CL in three, only one case had the same number of CL on both sets of images. Combination DIR/PSIR at 3T is superior to 3D MPRAGE for detection of cortical gray matter lesions in MS. The contrast-to-noise ratio of CL appears to be inferior on the MPRAGE images relative to DIR/PSIR. © 2013 Published by Elsevier B.V.

  5. Metastatic Breast Lesion to the Falx Detected with PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Chester; Schuster, David M. [Emory Univ., Atlanta (United States)

    2012-06-15

    Intracranial dural metastasis is increasingly encountered in imaging. Autopsies conducted on patients with advanced metastatic disease demonstrate dural involvement in 9% of cases, with breast and prostate cancer the most common primaries. Awareness of this entity and imaging appearances is especially important in evaluating malignancies prone to dural metastasis. A 57-year-old woman with a strong family history of breast cancer initially presented after self-detection of a right breast lump. Subsequent mammogram and biopsies yielded a diagnosis of right infiltrating ductal carcinoma with a positive lymph node as well as left invasive lobular carcinoma. Initial staging PET-CT (not shown) at the time of diagnosis demonstrated no abnormal FDG uptake remote from the breast. Neoadjuvant chemotherapy was instituted, and a PET-CT was obtained to evaluate disease response, demonstrating an approximately 1.8 cm hypermetabolic intra-cranial mass, localized to the region of the anterior corpus callosum on axian PET (Fig. 1a), axial fused PET-CT (Fig. 1b), and sagittal fused PET-CT (Fig. 1c) with a maximum SUV of 15.9. There was associated bifrontal vasogenic edema (Fig. 1d) on the CT demonstrated on brain windows. Marked progression of disease was noted elsewhere, including hypermetabolic adenopathy and skeletal disease. A contrast-enhanced MRI of the brain was obtained demonstrating extensive T1 hypointensity, T2, and FLAIR (Fig. 2a) hyperintensity in the bilateral paramedian frontallobes representing vasogenic edema. Post-contrast imaging demonstrated three solidly enhancing masses in the areas of described vasogenic edema, one large extra-axial and two sub-centimeter parenchymal lesions. The large extra-axial and two sub-centimeter parenchymal lesions. The large extra-axial mass demonstrated homogeneous solid enhancement, in the midline anteriorly centered on the falx, just superior to the anterior corpus callosum. This measured 1.7cm transverse x 3.1cm AP x 2.4cm

  6. Detection limit for rate fluctuations in inhomogeneous Poisson processes

    Science.gov (United States)

    Shintani, Toshiaki; Shinomoto, Shigeru

    2012-04-01

    Estimations of an underlying rate from data points are inevitably disturbed by the irregular occurrence of events. Proper estimation methods are designed to avoid overfitting by discounting the irregular occurrence of data, and to determine a constant rate from irregular data derived from a constant probability distribution. However, it can occur that rapid or small fluctuations in the underlying density are undetectable when the data are sparse. For an estimation method, the maximum degree of undetectable rate fluctuations is uniquely determined as a phase transition, when considering an infinitely long series of events drawn from a fluctuating density. In this study, we analytically examine an optimized histogram and a Bayesian rate estimator with respect to their detectability of rate fluctuation, and determine whether their detectable-undetectable phase transition points are given by an identical formula defining a degree of fluctuation in an underlying rate. In addition, we numerically examine the variational Bayes hidden Markov model in its detectability of rate fluctuation, and determine whether the numerically obtained transition point is comparable to those of the other two methods. Such consistency among these three principled methods suggests the presence of a theoretical limit for detecting rate fluctuations.

  7. Detection limit for rate fluctuations in inhomogeneous Poisson processes.

    Science.gov (United States)

    Shintani, Toshiaki; Shinomoto, Shigeru

    2012-04-01

    Estimations of an underlying rate from data points are inevitably disturbed by the irregular occurrence of events. Proper estimation methods are designed to avoid overfitting by discounting the irregular occurrence of data, and to determine a constant rate from irregular data derived from a constant probability distribution. However, it can occur that rapid or small fluctuations in the underlying density are undetectable when the data are sparse. For an estimation method, the maximum degree of undetectable rate fluctuations is uniquely determined as a phase transition, when considering an infinitely long series of events drawn from a fluctuating density. In this study, we analytically examine an optimized histogram and a Bayesian rate estimator with respect to their detectability of rate fluctuation, and determine whether their detectable-undetectable phase transition points are given by an identical formula defining a degree of fluctuation in an underlying rate. In addition, we numerically examine the variational Bayes hidden Markov model in its detectability of rate fluctuation, and determine whether the numerically obtained transition point is comparable to those of the other two methods. Such consistency among these three principled methods suggests the presence of a theoretical limit for detecting rate fluctuations.

  8. Fault Detection Using the Zero Crossing Rate | Osuagwu | Nigerian ...

    African Journals Online (AJOL)

    A method of fault detection based on the zero crossing rate of the signal, Z1, and the zero crossing rate of the first order difference signal. Z2, is presented. It is shown that the parameter pair (Z1, Z2) possesses adequate discriminating potential to classify a signature as good or defective. The parameter pair also carries ...

  9. Rate modulation detection thresholds for cochlear implant users.

    Science.gov (United States)

    Brochier, Tim; McKay, Colette; McDermott, Hugh

    2018-02-01

    The perception of temporal amplitude modulations is critical for speech understanding by cochlear implant (CI) users. The present study compared the ability of CI users to detect sinusoidal modulations of the electrical stimulation rate and current level, at different presentation levels (80% and 40% of the dynamic range) and modulation frequencies (10 and 100 Hz). Rate modulation detection thresholds (RMDTs) and amplitude modulation detection thresholds (AMDTs) were measured and compared to assess whether there was a perceptual advantage to either modulation method. Both RMDTs and AMDTs improved with increasing presentation level and decreasing modulation frequency. RMDTs and AMDTs were correlated, indicating that a common processing mechanism may underlie the perception of rate modulation and amplitude modulation, or that some subject-dependent factors affect both types of modulation detection.

  10. Detection of lesions in multiple sclerosis by 2D FLAIR and single-slab 3D FLAIR sequences at 3.0 T: initial results

    International Nuclear Information System (INIS)

    Bink, Andrea; Gaa, Jochen; Lanfermann, Heinrich; Zanella, Friedhelm E.; Schmitt, Melanie; Mugler, John P.

    2006-01-01

    The aim of this study was to compare conventional 2D FLAIR and single-slab 3D FLAIR sequences in the detection of lesions in patients with multiple sclerosis. Eight patients with MS were examined at 3.0 T by using a 2D FLAIR sequence and a single-slab 3D FLAIR sequence. A comparison of lesion detectability was performed for the following regions: periventricular, nonperiventricular/juxtacortical and infratentorial. The contrast-to-noise ratios (CNRs) between lesions and brain tissue and CSF were calculated for each sequence. A total of 424 lesions were found using the 2D FLAIR sequence, while with the 3D FLAIR sequence 719 lesions were found. With the 2D FLAIR sequence, 41% fewer lesions were detected than with the 3D FLAIR sequence. Further, 40% fewer supratentorial and 62.5% fewer infratentorial lesions were found with the 2D FLAIR sequence. In images acquired with the 3D FLAIR sequence, the lesions had significantly higher CNRs than in images acquired with the 2D FLAIR sequence. These are the first results using a single-slab 3D FLAIR sequence at 3.0 T for detection of lesions in patients with MS. With the 3D FLAIR sequence significantly higher CNRs were achieved and significantly more lesions in patients with MS were detected. (orig.)

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

    International Nuclear Information System (INIS)

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

    2006-01-01

    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 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 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

  12. Rapid noninvasive detection of experimental atherosclerotic lesions with novel 99mTc-labeled diadenosine tetraphosphates

    Science.gov (United States)

    Elmaleh, David R.; Narula, Jagat; Babich, John W.; Petrov, Artiom; Fischman, Alan J.; Khaw, Ban-An; Rapaport, Eliezer; Zamecnik, Paul C.

    1998-01-01

    The development of a noninvasive imaging procedure for identifying atherosclerotic lesions is extremely important for the clinical management of patients with coronary artery and peripheral vascular disease. Although numerous radiopharmaceuticals have been proposed for this purpose, none has demonstrated the diagnostic accuracy required to replace invasive angiography. In this report, we used the radiolabeled purine analog, 99mTc diadenosine tetraphosphate (Ap4A; AppppA, P1,P4-di(adenosine-5′)-tetraphosphate) and its analogue 99mTc AppCHClppA for imaging experimental atherosclerotic lesions in New Zealand White rabbits. Serial gamma camera images were obtained after intravenous injection of the radiolabeled dinucleotides. After acquiring the final images, the animals were sacrificed, ex vivo images of the aortas were recorded, and biodistribution was measured. 99mTc-Ap4A and 99mTc AppCHClppA accumulated rapidly in atherosclerotic abdominal aorta, and lesions were clearly visible within 30 min after injection in all animals that were studied. Both radiopharmaceuticals were retained in the lesions for 3 hr, and the peak lesion to normal vessel ratio was 7.4 to 1. Neither of the purine analogs showed significant accumulation in the abdominal aorta of normal (control) rabbits. The excised aortas showed lesion patterns that were highly correlated with the in vivo and ex vivo imaging results. The present study demonstrates that purine receptors are up-regulated in experimental atherosclerotic lesions and 99mTc-labeled purine analogs have potential for rapid noninvasive detection of plaque formation. PMID:9435254

  13. Detection of cervical precancerous lesions with Aptima HPV assays using SurePath preservative fluid specimens

    Directory of Open Access Journals (Sweden)

    Max Chernesky

    2017-06-01

    Full Text Available SurePath specimens from women referred to colposcopy were treated with Aptima Transfer Solution (ATS before testing in Aptima HPV (AHPV and Aptima HPV 16, 18/45 (AHPV-GT assays. Untreated SurePath specimens were tested with the cobas HPV test. PreservCyt specimens were assessed for cytology and tested with AHPV. High-grade cervical intraepithelial neoplasia lesions served as the reference standard. Excellent agreement (95.5%; k=0.91 was observed for ATS-treated SurePath specimens between Tigris and Panther systems and between the PreservCyt and ATS-treated SurePath specimens (91.1%, k=0.81 with the AHPV assay on Tigris. Agreement between the AHPV and cobas assays with SurePath specimens was substantial (89.9%, k=0.80. AHPV sensitivity for CIN2+(n=147 was 91.2% for SurePath and PreservCyt. Cobas HPV sensitivity was 93.9% for SurePath specimens. AHPV testing of SurePath specimens was more specific (59.4% than cobas (54.7% (p<0.001. Detection and genotyping showed similar absolute and relative risks. ATS-treated SurePath specimens tested with AHPV and AHPV-GT assays showed similar performance with greater specificity than cobas HPV on SurePath specimens. Similar overall results were seen using a CIN3 disease endpoint. Keywords: Human papillomavirus, SurePath, PreservCyt, Cervical intraepithelial neoplasia, CIN2+, Aptima transfer solution (ATS

  14. Fusion of classifiers for REIS-based detection of suspicious breast lesions

    Science.gov (United States)

    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 (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.

  15. Recurrence rate and patient satisfaction of CO2 laser evaporation of lesions in patients with hidradenitis suppurativa

    DEFF Research Database (Denmark)

    Mikkelsen, Peter Riis; Dufour, Deirde Nathalie; Zarchi, Kian

    2015-01-01

    : To determine the recurrence rate, time to recurrence, and factors influencing disease recurrence in skin treated with CO2 laser evaporation, and healing by secondary intention; and patients' satisfaction with treatment. METHODS: Fifty-eight patients treated with CO2 laser evaporation were interviewed regarding...... recurrence and satisfaction after a mean of 25.7 months. RESULTS: Seventeen of 58 (29%) reported recurrence of HS lesions within the borders of the treated areas after a mean of 12.7 months. Obesity was a risk factor for recurrence with a hazard ratio of 4.53. Fifty-five patients (95%) reported some or great...... improvement, and 91% would recommend the CO2 laser surgery to other HS patients. CONCLUSION: This study supports the claim that CO2 laser treatment is an effective modality for recurrent HS lesions in a majority of patients. The authors identified obesity as a risk factor for recurrence. Self...

  16. Skin lesion-associated pathogens from Octopus vulgaris: first detection of Photobacterium swingsii, Lactococcus garvieae and betanodavirus.

    Science.gov (United States)

    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.

  17. DOUBLE COMPACT OBJECTS. III. GRAVITATIONAL-WAVE DETECTION RATES

    Energy Technology Data Exchange (ETDEWEB)

    Dominik, Michal; Belczynski, Krzysztof; Bulik, Tomasz [Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warsaw (Poland); Berti, Emanuele [Department of Physics and Astronomy, The University of Mississippi, University, MS 38677 (United States); O’Shaughnessy, Richard [Center for Gravitation, Cosmology, and Astrophysics, University of Wisconsin-Milwaukee, Milwaukee, WI (United States); Mandel, Ilya [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Fryer, Christopher [CCS-2, MSD409, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Holz, Daniel E. [Enrico Fermi Institute, Department of Physics, and Kavli Institute for Cosmological Physics University of Chicago, Chicago, IL 60637 (United States); Pannarale, Francesco [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA (United Kingdom)

    2015-06-20

    The unprecedented range of second-generation gravitational-wave (GW) observatories calls for refining the predictions of potential sources and detection rates. The coalescence of double compact objects (DCOs)—i.e., neutron star–neutron star (NS–NS), black hole–neutron star (BH–NS), and black hole–black hole (BH–BH) binary systems—is the most promising source of GWs for these detectors. We compute detection rates of coalescing DCOs in second-generation GW detectors using the latest models for their cosmological evolution, and implementing inspiral-merger-ringdown gravitational waveform models in our signal-to-noise ratio calculations. We find that (1) the inclusion of the merger/ringdown portion of the signal does not significantly affect rates for NS–NS and BH–NS systems, but it boosts rates by a factor of ∼1.5 for BH–BH systems; (2) in almost all of our models BH–BH systems yield by far the largest rates, followed by NS–NS and BH–NS systems, respectively; and (3) a majority of the detectable BH–BH systems were formed in the early universe in low-metallicity environments. We make predictions for the distributions of detected binaries and discuss what the first GW detections will teach us about the astrophysics underlying binary formation and evolution.

  18. CT-guided preoperative needle localization of MRI-detected breast lesions

    Energy Technology Data Exchange (ETDEWEB)

    Giagounidis, Elektra M. E-mail: giagounjdis@online.de; Markus, Ruwe; Josef, Luetzeler; Wemer, Audretsch; Mahdi, Rezai; Bernward, Kurtz

    2001-08-01

    To assess the value of accurate preoperative CT-guided needle localization of occult breast lesions, we reviewed a total of 39 needle-directed biopsies of breast tumors in 24 women. The average age was 52.9 years (range 31-67). All lesions were nonpalpable and mammographically, as well as sonographically occult. They were solely seen on MR-images. After demonstrating the suspicious region on CT scans, a hookwire was inserted. The correct position was confirmed by a control scan. The subsequent histopathological examination showed that 28 of the lesions (71.8%) were benign, among them mastopathy, fibrosis, fibroadenoma, papilloma, intramammary lymph node, liponecrosis and epitheliosis. Eleven lesions (28%) were malignant and showed either lobular, ductal or tubular cancer. Our results endorse that CT guided needle localization is a helpful method that allows a precise surgical excision of the suspect area with the removal of a minimal amount of breast tissue.

  19. Detection and repair of a UV-induced photosensitive lesion in the DNA of human cells

    International Nuclear Information System (INIS)

    Francis, A.A.; Regan, J.D.

    1986-01-01

    Irradiation with UV light results in damage to the DNA of human cells. The most numerous lesions are pyrimidine dimers; however, other lesions are known to occur and may contribute to the overall deleterious effect of UV irradiation. The authors have observed evidence of a UV-induced lesion other than pyrimidine dimers in the DNA of human cells by measuring DNA strand breaks induced by irradiating with 313-nm light following UV (254-nm) irradiation. The data suggest that, in normal cells, the lesion responsible for this effect is rapidly repaired or altered; whereas, in xeroderma pigmentosum variant cells it seems to remain unchanged. Some change apparently occurs in the DNA of xeroderma pigmentosum group A cells which results in an increase in photolability. These data indicate a deficiency in DNA repair of xeroderma pigmentosum variant cells as well as in xeroderma pigmentosum group A cells. (Auth.)

  20. Detection and Characterization of Focal Hepatic lesions using Magnetic resonance Imaging

    International Nuclear Information System (INIS)

    Pulgarin, Luis G; Delgado, Jorge Andres; Toro Nancy

    2008-01-01

    A retrospective one year study was performed from June 2006 to June 2007. A total of ten focal liver lesions in 60 patients were examined, describing their magnetic resonance (MR) characteristics, using T1, T2 and dynamic Gd-enhanced T1 weighted sequences with and without fat suppression. Lesions were classified into benign or malignant tumors and a diagnosis was proposed. Specific diagnoses such as simple cyst, abscess, hemangioma, focal nodular hyperplasia, hepatocellular carcinoma, and cholangiocarcinoma were reported.

  1. Probabilistic pipe fracture evaluations for leak-rate-detection applications

    International Nuclear Information System (INIS)

    Rahman, S.; Ghadiali, N.; Paul, D.; Wilkowski, G.

    1995-04-01

    Regulatory Guide 1.45, open-quotes Reactor Coolant Pressure Boundary Leakage Detection Systems,close quotes was published by the U.S. Nuclear Regulatory Commission (NRC) in May 1973, and provides guidance on leak detection methods and system requirements for Light Water Reactors. Additionally, leak detection limits are specified in plant Technical Specifications and are different for Boiling Water Reactors (BWRs) and Pressurized Water Reactors (PWRs). These leak detection limits are also used in leak-before-break evaluations performed in accordance with Draft Standard Review Plan, Section 3.6.3, open-quotes Leak Before Break Evaluation Proceduresclose quotes where a margin of 10 on the leak detection limit is used in determining the crack size considered in subsequent fracture analyses. This study was requested by the NRC to: (1) evaluate the conditional failure probability for BWR and PWR piping for pipes that were leaking at the allowable leak detection limit, and (2) evaluate the margin of 10 to determine if it was unnecessarily large. A probabilistic approach was undertaken to conduct fracture evaluations of circumferentially cracked pipes for leak-rate-detection applications. Sixteen nuclear piping systems in BWR and PWR plants were analyzed to evaluate conditional failure probability and effects of crack-morphology variability on the current margins used in leak rate detection for leak-before-break

  2. Postoperative quality of life outcome and employment in patients undergoing resection of epileptogenic lesions detected by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Moritake, Kouzo; Akiyama, Yasuhiko; Nagai, Hidemasa; Maruyama, Nobuyuki; Takada, Daikei; Daisu, Mitsuhiro; Nagasako, Noriko; Mikuni, Nobuhiro; Hashimoto, Nobuo

    2009-01-01

    The long-term postoperative improvement of quality of life (QOL) and employment were investigated in patients undergoing resection of epileptogenic lesions detected by magnetic resonance (MR) imaging to identify the associated preoperative factors. Thirty of 47 patients who underwent lesionectomy between 1987-2001 replied to questionnaires. Patients with extratemporal resection outnumbered those with temporal lobe resection. The mean follow-up period was 12.4±3.7 years. An arbitrary score for quantitatively assessing QOL was assigned. The mean increases in QOL score points were significantly higher in the late childhood onset group than those in the early childhood onset group, and were also significantly higher in the temporal resection group and extratemporal resection of non-dysplastic cortical pathology group than in the extratemporal resection of dysplastic cortical pathology group. Postoperative QOL improvement and occupational status of patients depended on the completeness of seizure control. Resection of lesions detected by MR imaging in patients with intractable epilepsy resulted in effective long-term QOL improvement and postoperative occupational status. Favorable outcome was related mainly to the pathology of the epileptogenic lesions, whether the lesion site was temporal or extratemporal, and the completeness of seizure control. (author)

  3. BIRDNEST: Bayesian Inference for Ratings-Fraud Detection

    OpenAIRE

    Hooi, Bryan; Shah, Neil; Beutel, Alex; Gunnemann, Stephan; Akoglu, Leman; Kumar, Mohit; Makhija, Disha; Faloutsos, Christos

    2015-01-01

    Review fraud is a pervasive problem in online commerce, in which fraudulent sellers write or purchase fake reviews to manipulate perception of their products and services. Fake reviews are often detected based on several signs, including 1) they occur in short bursts of time; 2) fraudulent user accounts have skewed rating distributions. However, these may both be true in any given dataset. Hence, in this paper, we propose an approach for detecting fraudulent reviews which combines these 2 app...

  4. Bayesian analysis of energy and count rate data for detection of low count rate radioactive sources.

    Science.gov (United States)

    Klumpp, John; Brandl, Alexander

    2015-03-01

    A particle counting and detection system is proposed that searches for elevated count rates in multiple energy regions simultaneously. The system analyzes time-interval data (e.g., time between counts), as this was shown to be a more sensitive technique for detecting low count rate sources compared to analyzing counts per unit interval (Luo et al. 2013). Two distinct versions of the detection system are developed. The first is intended for situations in which the sample is fixed and can be measured for an unlimited amount of time. The second version is intended to detect sources that are physically moving relative to the detector, such as a truck moving past a fixed roadside detector or a waste storage facility under an airplane. In both cases, the detection system is expected to be active indefinitely; i.e., it is an online detection system. Both versions of the multi-energy detection systems are compared to their respective gross count rate detection systems in terms of Type I and Type II error rates and sensitivity.

  5. Effect of Thin Prep® imaging system on laboratory rate and relative sensitivity of atypical squamous cells, high-grade squamous intraepithelial lesion not excluded and high-grade squamous intraepithelial lesion interpretations

    Directory of Open Access Journals (Sweden)

    Brooke R Koltz

    2013-01-01

    % of TIS cases and 69% manually screened cases showed CIN II/III on follow-up. TIS was 26% less sensitive relative to manual screening for ASC-H cases and 3% less sensitive for HGSIL. Conclusion: The similar rate of detection using TIS with an equal percentage of histologic correlation for ASC-H and HGSIL lesions on follow-up histology suggests patients screened by the TIS method are being sent for appropriate follow-up surveillance and treatment. A high-grade or possible high-grade lesion is as likely to be detected by TIS as by a manual screen. The similarities in relative sensitivity and specificity in a direct comparison between manual and TIS screening methodologies indicate that TIS compared to manual screening does not affect detection in patients with high-grade cervical lesions.

  6. "Blind spots" in forensic autopsy: improved detection of retrobulbar hemorrhage and orbital lesions by postmortem computed tomography (PMCT).

    Science.gov (United States)

    Flach, P M; Egli, T C; Bolliger, S A; Berger, N; Ampanozi, G; Thali, M J; Schweitzer, W

    2014-09-01

    The purpose of this study was to correlate the occurrence of retrobulbar hemorrhage (RBH) with mechanism of injury, external signs and autopsy findings to postmortem computed tomography (PMCT). Six-teen subjects presented with RBH and underwent PMCT, external inspection and conventional autopsy. External inspection was evaluated for findings of the bulbs, black eye, raccoon eyes and Battle's sign. Fractures of the viscerocranium, orbital lesions and RBH were evaluated by PMCT. Autopsy and PMCT was evaluated for orbital roof and basilar skull fracture. The leading manner of death was accident with central regulatory failure in cases of RBH (31.25%). Imaging showed a high sensitivity in detection of orbital roof and basilar skull fractures (100%), but was less specific compared to autopsy. Volume of RBH (0.1-2.4ml) correlated positively to the presence of Battle's sign (pautopsy. PMCT was superior in detecting osseous lesions, scrutinizing autopsy as the gold standard. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. Nested PCR Assay for Detection of Leishmania donovani in Slit Aspirates from Post-Kala-Azar Dermal Leishmaniasis Lesions

    Science.gov (United States)

    Sreenivas, Gannavaram; Ansari, N. A.; Kataria, Joginder; Salotra, Poonam

    2004-01-01

    A nested PCR assay to detect parasite DNA in slit aspirates from skin lesions of patients with post-kala-azar dermal lesihmaniasis (PKDL) is described. PCR results were positive in 27 of 29 (93%) samples by nested PCR assay, while only 20 of 29 (69%) were positive in a primary PCR assay. The nested PCR assay allowed reliable diagnosis of PKDL in a noninvasive manner. PMID:15071047

  8. Nested PCR Assay for Detection of Leishmania donovani in Slit Aspirates from Post-Kala-Azar Dermal Leishmaniasis Lesions

    OpenAIRE

    Sreenivas, Gannavaram; Ansari, N. A.; Kataria, Joginder; Salotra, Poonam

    2004-01-01

    A nested PCR assay to detect parasite DNA in slit aspirates from skin lesions of patients with post-kala-azar dermal lesihmaniasis (PKDL) is described. PCR results were positive in 27 of 29 (93%) samples by nested PCR assay, while only 20 of 29 (69%) were positive in a primary PCR assay. The nested PCR assay allowed reliable diagnosis of PKDL in a noninvasive manner.

  9. Evaluation of accuracy of intra operative imprint cytology for detection of breast lesions

    International Nuclear Information System (INIS)

    Mahmood, Z.; Shahbaz, A.; Qureshi, A.; Aziz, N.; Niazi, S.; Qureshi, S.; Bukhari, M.H.

    2010-01-01

    Objective: To determine the accuracy of imprint cytology as an intraoperative diagnostic procedure for breast lesions with histopathological correlation. Materials and Methods: This was a descriptive study on 40 cases of breast lesions comprising of inflammatory, benign and malignant lesions including their margins etc. It was conducted at King Edward Medical University, Lahore in collaboration with all Surgical Departments of Mayo Hospital. Relevant clinical data was recorded in a proforma. Both touch and scrape imprints were prepared from all the lesions and stained with May-Grunwaled Giemsa and Haematoxylin and Eosin stains. The imprints were subsequently compared with histopathology sections. Results: When we used atypical cases as negative both touch and scrape imprints gave sensitivity, specificity, positive predictive value, negative predictive value and accuracy at 100%. However when we used cases with atypia as positive, sensitivity and negative predictive value were 100% with both touch and scrape imprints. Specificity, positive predictive value and accuracy were 71%, 86%, 85.5% respectively with touch imprints and 78%, 89%, 89% respectively with scrape imprints. No diagnostic difference was noted between the results of both stains. All the imprints were well correlated with histopathological diagnosis. Conclusion: Imprint cytology is an accurate and simple intraoperative method for diagnosing breast lesions. It can provide the surgeons with information regarding immediate clinical and surgical interventions. (author)

  10. A comparison of lesion detection and conspicuity on T2-weighted images (T2 FFE), FLAIR and diffusion-weighted images in patients with traumatic brain injury

    International Nuclear Information System (INIS)

    Kwon, Eun Yong; Lee, Myeong sub; Kim, Myung Soon; Hong, In Soo; Kim, Young Ju; Whang, Gum

    2001-01-01

    To compare the lesion detectability and conspicuity in traumatic brain injury on T-2 FFE, FLAIR and diffusion weighted imaging (DWI) sequences. Thirty-three patients who underwent MR brain imaging after traumatic brain injury were reviewed. T-2 FFE, FLAIR and diffusion-weighted MR sequences were obtained and were compared in terms of the detectability and conspicuity of intra- and extra-axial lesions which showed abnormal signal intensities. Among 33 patients, a total of 108 lesions were found, T-2 FFE sequences detected 88(81%) of these, FLAIR sequences 91%(84%), and diffusion-weighted sequences 57(52%). In the case of petechial hemorrhagic lesions, 16 were detected by T-2 FFE imaging but only one by FLAIR and one by DWI. Sixteen extra-axial lesions (73%) were detected by T-2 FFE, 21 (95%) by FLAIR, and 11(50%) by DWI. Lesion conspicuity on FLAIR images was judged superior to that on T-2 FFE and diffusion-weighted images in 42 lesions (75%). Eleven extra-axial Lesions (92%) were more conspicuous on FLAIR than on T-2 FFE and DWI. For detecting traumatic brain lesions and determining their conspicuity, FLAIR imaging was more useful than T-2 FFE and diffusion weighting , while T-2 FFE imaging was more sensitive for the detecion of petechial hemorrhage. Although diffusion-weighted imaging was generally inferior to both FLAIR and T-2 FFE in terms of lesion detection and conspicuity, for some lesions it was superior. The results suggest that images obtained at each pulse sequence can be used as complementary imaging sequences, and that in traumatic brain injury, the acquisition of FLAIR, T-2 FFE and diffusion-weighted images is useful

  11. Automated Whole-Body Bone Lesion Detection for Multiple Myeloma on 68Ga-Pentixafor PET/CT Imaging Using Deep Learning Methods.

    Science.gov (United States)

    Xu, Lina; Tetteh, Giles; Lipkova, Jana; Zhao, Yu; Li, Hongwei; Christ, Patrick; Piraud, Marie; Buck, Andreas; Shi, Kuangyu; Menze, Bjoern H

    2018-01-01

    The identification of bone lesions is crucial in the diagnostic assessment of multiple myeloma (MM). 68 Ga-Pentixafor PET/CT can capture the abnormal molecular expression of CXCR-4 in addition to anatomical changes. However, whole-body detection of dozens of lesions on hybrid imaging is tedious and error prone. It is even more difficult to identify lesions with a large heterogeneity. This study employed deep learning methods to automatically combine characteristics of PET and CT for whole-body MM bone lesion detection in a 3D manner. Two convolutional neural networks (CNNs), V-Net and W-Net, were adopted to segment and detect the lesions. The feasibility of deep learning for lesion detection on 68 Ga-Pentixafor PET/CT was first verified on digital phantoms generated using realistic PET simulation methods. Then the proposed methods were evaluated on real 68 Ga-Pentixafor PET/CT scans of MM patients. The preliminary results showed that deep learning method can leverage multimodal information for spatial feature representation, and W-Net obtained the best result for segmentation and lesion detection. It also outperformed traditional machine learning methods such as random forest classifier (RF), k -Nearest Neighbors ( k -NN), and support vector machine (SVM). The proof-of-concept study encourages further development of deep learning approach for MM lesion detection in population study.

  12. Automated Whole-Body Bone Lesion Detection for Multiple Myeloma on 68Ga-Pentixafor PET/CT Imaging Using Deep Learning Methods

    Directory of Open Access Journals (Sweden)

    Lina Xu

    2018-01-01

    Full Text Available The identification of bone lesions is crucial in the diagnostic assessment of multiple myeloma (MM. 68Ga-Pentixafor PET/CT can capture the abnormal molecular expression of CXCR-4 in addition to anatomical changes. However, whole-body detection of dozens of lesions on hybrid imaging is tedious and error prone. It is even more difficult to identify lesions with a large heterogeneity. This study employed deep learning methods to automatically combine characteristics of PET and CT for whole-body MM bone lesion detection in a 3D manner. Two convolutional neural networks (CNNs, V-Net and W-Net, were adopted to segment and detect the lesions. The feasibility of deep learning for lesion detection on 68Ga-Pentixafor PET/CT was first verified on digital phantoms generated using realistic PET simulation methods. Then the proposed methods were evaluated on real 68Ga-Pentixafor PET/CT scans of MM patients. The preliminary results showed that deep learning method can leverage multimodal information for spatial feature representation, and W-Net obtained the best result for segmentation and lesion detection. It also outperformed traditional machine learning methods such as random forest classifier (RF, k-Nearest Neighbors (k-NN, and support vector machine (SVM. The proof-of-concept study encourages further development of deep learning approach for MM lesion detection in population study.

  13. Unenhanced breast MRI (STIR, T2-weighted TSE, DWIBS): An accurate and alternative strategy for detecting and differentiating breast lesions.

    Science.gov (United States)

    Telegrafo, Michele; Rella, Leonarda; Stabile Ianora, Amato Antonio; Angelelli, Giuseppe; Moschetta, Marco

    2015-10-01

    To assess the role of STIR, T2-weighted TSE and DWIBS sequences for detecting and characterizing breast lesions and to compare unenhanced (UE)-MRI results with contrast-enhanced (CE)-MRI and histological findings, having the latter as the reference standard. Two hundred eighty consecutive patients (age range, 27-73 years; mean age±standard deviation (SD), 48.8±9.8years) underwent MR examination with a diagnostic protocol including STIR, T2-weighted TSE, THRIVE and DWIBS sequences. Two radiologists blinded to both dynamic sequences and histological findings evaluated in consensus STIR, T2-weighted TSE and DWIBS sequences and after two weeks CE-MRI images searching for breast lesions. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy for UE-MRI and CE-MRI were calculated. UE-MRI results were also compared with CE- MRI. UE-MRI sequences obtained sensitivity, specificity, diagnostic accuracy, PPV and NPV values of 94%, 79%, 86%, 79% and 94%, respectively. CE-MRI sequences obtained sensitivity, specificity, diagnostic accuracy, PPV and NPV values of 98%, 83%, 90%, 84% and 98%, respectively. No statistically significant difference between UE-MRI and CE-MRI was found. Breast UE-MRI could represent an accurate diagnostic tool and a valid alternative to CE-MRI for evaluating breast lesions. STIR and DWIBS sequences allow to detect breast lesions while T2-weighted TSE sequences and ADC values could be useful for lesion characterization. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Heart rate detection from an electronic weighing scale

    International Nuclear Information System (INIS)

    González-Landaeta, R; Casas, O; Pallàs-Areny, R

    2008-01-01

    We propose a novel technique for beat-to-beat heart rate detection based on the ballistocardiographic (BCG) force signal from a subject standing on a common electronic weighing scale. The detection relies on sensing force variations related to the blood acceleration in the aorta, works even if wearing footwear and does not require any sensors attached to the body because it uses the load cells in the scale. We have devised an approach to estimate the sensitivity and frequency response of three commercial weighing scales to assess their capability to detect the BCG force signal. Static sensitivities ranged from 490 nV V −1 N −1 to 1670 nV V −1 N −1 . The frequency response depended on the subject's mass but it was broad enough for heart rate estimation. We have designed an electronic pulse detection system based on off-the-shelf integrated circuits to sense heart-beat-related force variations of about 0.24 N. The signal-to-noise ratio of the main peaks of the force signal detected was higher than 30 dB. A Bland–Altman plot was used to compare the RR time intervals estimated from the ECG and BCG force signals for 17 volunteers. The error was ±21 ms, which makes the proposed technique suitable for short-term monitoring of the heart rate

  15. Adenoma detection rate varies greatly during colonoscopy training

    NARCIS (Netherlands)

    van Doorn, Sascha C.; Klanderman, Robert B.; Hazewinkel, Yark; Fockens, Paul; Dekker, Evelien

    2015-01-01

    The adenoma detection rate (ADR) is considered the most important quality indicator for colonoscopy and varies widely among colonoscopists. It is unknown whether the ADR of gastroenterology consultants can already be predicted during their colonoscopy training. To evaluate the ADR of fellows in

  16. EUROCAT website data on prenatal detection rates of congenital anomalies

    NARCIS (Netherlands)

    Garne, Ester; Dolk, Helen; Loane, Maria; Boyd, Patricia A.

    2010-01-01

    The EUROCAT website www.eurocat-network.eu publishes prenatal detection rates for major congenital anomalies using data from European population-based congenital anomaly registers, covering 28% of the EU population as well as non-EU countries. Data are updated annually. This information can be

  17. Novel Method For Low-Rate Ddos Attack Detection

    Science.gov (United States)

    Chistokhodova, A. A.; Sidorov, I. D.

    2018-05-01

    The relevance of the work is associated with an increasing number of advanced types of DDoS attacks, in particular, low-rate HTTP-flood. Last year, the power and complexity of such attacks increased significantly. The article is devoted to the analysis of DDoS attacks detecting methods and their modifications with the purpose of increasing the accuracy of DDoS attack detection. The article details low-rate attacks features in comparison with conventional DDoS attacks. During the analysis, significant shortcomings of the available method for detecting low-rate DDoS attacks were found. Thus, the result of the study is an informal description of a new method for detecting low-rate denial-of-service attacks. The architecture of the stand for approbation of the method is developed. At the current stage of the study, it is possible to improve the efficiency of an already existing method by using a classifier with memory, as well as additional information.

  18. EUROCAT website data on prenatal detection rates of congenital anomalies

    DEFF Research Database (Denmark)

    Garne, Ester; Dolk, Helen; Loane, Maria

    2010-01-01

    The EUROCAT website www.eurocat-network.eu publishes prenatal detection rates for major congenital anomalies using data from European population-based congenital anomaly registers, covering 28% of the EU population as well as non-EU countries. Data are updated annually. This information can be us...

  19. Detection of retinal lesions in diabetic retinopathy: comparative evaluation of 7-field digital color photography versus red-free photography.

    Science.gov (United States)

    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

  20. Comparison of triple dose versus standard dose gadolinium-DTPA for detection of MRI enhancing lesions in patients with primary progressive multiple sclerosis.

    Science.gov (United States)

    Filippi, M; Campi, A; Martinelli, V; Colombo, B; Yousry, T; Canal, N; Scotti, G; Comi, G

    1995-01-01

    This study was performed to evaluate whether a triple dose of gadolinium-DTPA (Gd-DTPA) increases the sensitivity of brain MRI for detecting enhancing lesions in patients with primary progressive multiple sclerosis (PPMS). T1 weighted brain MRI was obtained for 10 patients with PPMS in two sessions. In the first session, one scan was obtained five to seven minutes after the injection of 0.1 mmol/kg Gd-DTPA (standard dose). In the second session, six to 24 hours later, one scan before and two scans five to seven minutes and one hour after the injection of 0.3 mmol/kg Gd-DTPA (triple dose) were obtained. Four enhancing lesions were detected in two patients when the standard dose of Gd-DTPA was used. The numbers of enhancing lesions increased to 13 and the numbers of patients with such lesions to five when the triple dose of Gd-DTPA was used and to 14 and six in the one hour delayed scans. The mean contrast ratio for enhancing lesions detected with the triple dose of Gd-DTPA was higher than those for lesions present in both the standard dose (P DTPA many more enhancing lesions can be detected in patients with PPMS. This is important both for planning clinical trials and for detecting the presence of inflammation in vivo in the lesions of such patients. Images PMID:8530944

  1. Impact of model-based iterative reconstruction on low-contrast lesion detection and image quality in abdominal CT: a 12-reader-based comparative phantom study with filtered back projection at different tube voltages

    Energy Technology Data Exchange (ETDEWEB)

    Euler, Andre; Stieltjes, Bram; Eichenberger, Reto; Reisinger, Clemens; Hirschmann, Anna; Zaehringer, Caroline; Kircher, Achim; Streif, Matthias; Bucher, Sabine; Buergler, David; D' Errico, Luigia; Kopp, Sebastien; Wilhelm, Markus [University Hospital Basel, Clinic of Radiology and Nuclear Medicine, Basel (Switzerland); Szucs-Farkas, Zsolt [Hospital Centre of Biel, Institute of Radiology, Biel (Switzerland); Schindera, Sebastian T. [University Hospital Basel, Clinic of Radiology and Nuclear Medicine, Basel (Switzerland); Cantonal Hospital Aarau, Institute of Radiology, Aarau (Switzerland)

    2017-12-15

    To evaluate the impact of model-based iterative reconstruction (MBIR) on image quality and low-contrast lesion detection compared with filtered back projection (FBP) in abdominal computed tomography (CT) of simulated medium and large patients at different tube voltages. A phantom with 45 hypoattenuating lesions was placed in two water containers and scanned at 70, 80, 100, and 120 kVp. The 120-kVp protocol served as reference, and the volume CT dose index (CTDI{sub vol}) was kept constant for all protocols. The datasets were reconstructed with MBIR and FBP. Image noise and contrast-to-noise-ratio (CNR) were assessed. Low-contrast lesion detectability was evaluated by 12 radiologists. MBIR decreased the image noise by 24% and 27%, and increased the CNR by 30% and 29% for the medium and large phantoms, respectively. Lower tube voltages increased the CNR by 58%, 46%, and 16% at 70, 80, and 100 kVp, respectively, compared with 120 kVp in the medium phantom and by 9%, 18% and 12% in the large phantom. No significant difference in lesion detection rate was observed (medium: 79-82%; large: 57-65%; P > 0.37). Although MBIR improved quantitative image quality compared with FBP, it did not result in increased low-contrast lesion detection in abdominal CT at different tube voltages in simulated medium and large patients. (orig.)

  2. Detection of white spot lesions by segmenting laser speckle images using computer vision methods.

    Science.gov (United States)

    Gavinho, Luciano G; Araujo, Sidnei A; Bussadori, Sandra K; Silva, João V P; Deana, Alessandro M

    2018-05-05

    This paper aims to develop a method for laser speckle image segmentation of tooth surfaces for diagnosis of early stages caries. The method, applied directly to a raw image obtained by digital photography, is based on the difference between the speckle pattern of a carious lesion tooth surface area and that of a sound area. Each image is divided into blocks which are identified in a working matrix by their χ 2 distance between block histograms of the analyzed image and the reference histograms previously obtained by K-means from healthy (h_Sound) and lesioned (h_Decay) areas, separately. If the χ 2 distance between a block histogram and h_Sound is greater than the distance to h_Decay, this block is marked as decayed. The experiments showed that the method can provide effective segmentation for initial lesions. We used 64 images to test the algorithm and we achieved 100% accuracy in segmentation. Differences between the speckle pattern of a sound tooth surface region and a carious region, even in the early stage, can be evidenced by the χ 2 distance between histograms. This method proves to be more effective for segmenting the laser speckle image, which enhances the contrast between sound and lesioned tissues. The results were obtained with low computational cost. The method has the potential for early diagnosis in a clinical environment, through the development of low-cost portable equipment.

  3. Detection of optic nerve lesions in optic neuritis using frequency-selective fat-saturation sequences

    International Nuclear Information System (INIS)

    Miller, D.H.; MacManus, D.G.; Bartlett, P.A.; Kapoor, R.; Morrissey, S.P.; Moseley, I.F.

    1993-01-01

    MRI was performed on seven patients with acute optic neuritis, using two sequences which suppress the signal from orbital fat: frequency-selective fat-saturation and inversion recovery with a short inversion time. Lesions were seen on both sequences in all the symptomatic optic nerves studied. (orig.)

  4. Three dimensional quantitative coronary angiography can detect reliably ischemic coronary lesions based on fractional flow reserve.

    Science.gov (United States)

    Chung, Woo-Young; Choi, Byoung-Joo; Lim, Seong-Hoon; Matsuo, Yoshiki; Lennon, Ryan J; Gulati, Rajiv; Sandhu, Gurpreet S; Holmes, David R; Rihal, Charanjit S; Lerman, Amir

    2015-06-01

    Conventional coronary angiography (CAG) has limitations in evaluating lesions producing ischemia. Three dimensional quantitative coronary angiography (3D-QCA) shows reconstructed images of CAG using computer based algorithm, the Cardio-op B system (Paieon Medical, Rosh Ha'ayin, Israel). The aim of this study was to evaluate whether 3D-QCA can reliably predict ischemia assessed by myocardial fractional flow reserve (FFR) < 0.80. 3D-QCA images were reconstructed from CAG which also were evaluated with FFR to assess ischemia. Minimal luminal diameter (MLD), percent diameter stenosis (%DS), minimal luminal area (MLA), and percent area stenosis (%AS) were obtained. The results of 3D-QCA and FFR were compared. A total of 266 patients was enrolled for the present study. FFR for all lesions ranged from 0.57 to 1.00 (0.85 ± 0.09). Measurement of MLD, %DS, MLA, and %AS all were significantly correlated with FFR (r = 0.569, 0609, 0.569, 0.670, respectively, all P < 0.001). In lesions with MLA < 4.0 mm(2), %AS of more than 65.5% had a 80% sensitivity and a 83% specificity to predict FFR < 0.80 (area under curve, AUC was 0.878). 3D-QCA can reliably predict coronary lesions producing ischemia and may be used to guide therapeutic approach for coronary artery disease.

  5. Contrast enhanced digital mammography: Is it useful in detecting lesions in edematous breast?

    Directory of Open Access Journals (Sweden)

    Noha Abd ElShafy ElSaid

    2015-09-01

    Conclusion: Dual-energy contrast-enhanced digital mammography is a useful technique in identification of lesions in mammographically dense edematous breasts and proved to be a useful tool in the follow-up of cases presenting by edema after conservative breast surgery and chemotherapy.

  6. Detecting ICRS grade 1 cartilage lesions in anterior cruciate ligament injury using T1ρ and T2 mapping

    Energy Technology Data Exchange (ETDEWEB)

    Nishioka, Hiroaki, E-mail: kinuhnishiok@fc.kuh.kumamoto-u.ac.jp [Department of Orthopaedic Surgery, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556 (Japan); Hirose, Jun, E-mail: hirojun-mk@umin.ac.jp [Department of Orthopaedic Surgery, Kumamoto University Hospital, 1-1-1 Honjo, Kumamoto 860-8556 (Japan); Nakamura, Eiichi, E-mail: h@kumamoto-u.ac.jp [Department of Orthopaedic Surgery, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556 (Japan); Okamoto, Nobukazu, E-mail: nobuoka9999@fc.kuh.kumamoto-u.ac.jp [Department of Orthopaedic Surgery, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556 (Japan); Karasugi, Tatsuki, E-mail: tatsukik@fc.kuh.kumamoto-u.ac.jp [Department of Orthopaedic Surgery, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556 (Japan); Taniwaki, Takuya, E-mail: takuyataniwaki@fc.kuh.kumamoto-u.ac.jp [Department of Orthopaedic Surgery, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556 (Japan); Okada, Tatsuya, E-mail: tatsuya-okada@fc.kuh.kumamoto-u.ac.jp [Department of Orthopaedic Surgery, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556 (Japan); Yamashita, Yasuyuki, E-mail: yama@kumamoto-u.ac.jp [Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556 (Japan); Mizuta, Hiroshi, E-mail: mizuta@kumamoto-u.ac.jp [Department of Orthopaedic Surgery, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556 (Japan)

    2013-09-15

    Objective: The purpose of this study was to clarify the detectability of the International Cartilage Repair Society (ICRS) grade 1 cartilage lesions in anterior cruciate ligament (ACL)–injured knees using T1ρ and T2 mapping. Materials and Methods: We performed preoperative T1ρ and T2 mapping and 3D gradient–echo with water–selective excitation (WATS) sequences on 37 subjects with ACL injuries. We determined the detectability on 3D WATS based on arthroscopic findings. The T1ρ and T2 values (ms) were measured in the regions of interest that were placed on the weight–bearing cartilage of the femoral condyle. The receiver operating characteristic (ROC) curve based on these values was constructed using the arthroscopic findings as a reference standard. The evaluation of cartilage was carried out only in the weight–bearing cartilage. The cut–off values for determining the presence of a cartilage injury were determined using each ROC curve, and the detectability was calculated for the T1ρ and T2 mapping. Results: The cut–off values for the T1ρ and T2 were 41.6 and 41.2, respectively. The sensitivity and specificity of T1ρ were 91.2% and 89.5%, respectively, while those of T2 were 76.5% and 81.6%, respectively. For the 3D WATS images, the same values were 58.8% and 78.9%, respectively. Conclusions: Our study demonstrated that the T1ρ and T2 values were significantly higher for ICRS grade 1 cartilage lesions than for normal cartilage and that the two mappings were able to non–invasively detect ICRS grade 1 cartilage lesions in the ACL–injured knee with a higher detectability than were 3D WATS images.

  7. PET/CT detectability and classification of simulated pulmonary lesions using an SUV correction scheme

    Science.gov (United States)

    Morrow, Andrew N.; Matthews, Kenneth L., II; Bujenovic, Steven

    2008-03-01

    Positron emission tomography (PET) and computed tomography (CT) together are a powerful diagnostic tool, but imperfect image quality allows false positive and false negative diagnoses to be made by any observer despite experience and training. This work investigates PET acquisition mode, reconstruction method and a standard uptake value (SUV) correction scheme on the classification of lesions as benign or malignant in PET/CT images, in an anthropomorphic phantom. The scheme accounts for partial volume effect (PVE) and PET resolution. The observer draws a region of interest (ROI) around the lesion using the CT dataset. A simulated homogenous PET lesion of the same shape as the drawn ROI is blurred with the point spread function (PSF) of the PET scanner to estimate the PVE, providing a scaling factor to produce a corrected SUV. Computer simulations showed that the accuracy of the corrected PET values depends on variations in the CT-drawn boundary and the position of the lesion with respect to the PET image matrix, especially for smaller lesions. Correction accuracy was affected slightly by mismatch of the simulation PSF and the actual scanner PSF. The receiver operating characteristic (ROC) study resulted in several observations. Using observer drawn ROIs, scaled tumor-background ratios (TBRs) more accurately represented actual TBRs than unscaled TBRs. For the PET images, 3D OSEM outperformed 2D OSEM, 3D OSEM outperformed 3D FBP, and 2D OSEM outperformed 2D FBP. The correction scheme significantly increased sensitivity and slightly increased accuracy for all acquisition and reconstruction modes at the cost of a small decrease in specificity.

  8. Reliability of cortical lesion detection on double inversion recovery MRI applying the MAGNIMS-Criteria in multiple sclerosis patients within a 16-months period.

    Directory of Open Access Journals (Sweden)

    Tobias Djamsched Faizy

    Full Text Available In patients with multiple sclerosis (MS, Double Inversion Recovery (DIR magnetic resonance imaging (MRI can be used to identify cortical lesions (CL. We sought to evaluate the reliability of CL detection on DIR longitudinally at multiple subsequent time-points applying the MAGNIMs scoring criteria for CLs.26 MS patients received a 3T-MRI (Siemens, Skyra with DIR at 12 time-points (TP within a 16 months period. Scans were assessed in random order by two different raters. Both raters separately marked all CLs on each scan and total lesion numbers were obtained for each scan-TP and patient. After a retrospective re-evaluation, the number of consensus CLs (conL was defined as the total number of CLs, which both raters finally agreed on. CLs volumes, relative signal intensities and CLs localizations were determined. Both ratings (conL vs. non-consensus scoring were compared for further analysis.A total number of n = 334 CLs were identified by both raters in 26 MS patients with a first agreement of both raters on 160 out of 334 of the CLs found (κ = 0.48. After the retrospective re-evaluation, consensus agreement increased to 233 out of 334 CL (κ = 0.69. 93.8% of conL were visible in at least 2 consecutive TP. 74.7% of the conL were visible in all 12 consecutive TP. ConL had greater mean lesion volumes and higher mean signal intensities compared to lesions that were only detected by one of the raters (p<0.05. A higher number of CLs in the frontal, parietal, temporal and occipital lobe were identified by both raters than the number of those only identified by one of the raters (p<0.05.After a first assessment, slightly less than a half of the CL were considered as reliably detectable on longitudinal DIR images. A retrospective re-evaluation notably increased the consensus agreement. However, this finding is narrowed, considering the fact that retrospective evaluation steps might not be practicable in clinical routine. Lesions that were not reliably

  9. QRS peak detection for heart rate monitoring on Android smartphone

    Science.gov (United States)

    Pambudi Utomo, Trio; Nuryani, Nuryani; Darmanto

    2017-11-01

    In this study, Android smartphone is used for heart rate monitoring and displaying electrocardiogram (ECG) graph. Heart rate determination is based on QRS peak detection. Two methods are studied to detect the QRS complex peak; they are Peak Threshold and Peak Filter. The acquisition of ECG data is utilized by AD8232 module from Analog Devices, three electrodes, and Microcontroller Arduino UNO R3. To record the ECG data from a patient, three electrodes are attached to particular body’s surface of a patient. Patient’s heart activity which is recorded by AD8232 module is decoded by Arduino UNO R3 into analog data. Then, the analog data is converted into a voltage value (mV) and is processed to get the QRS complex peak. Heart rate value is calculated by Microcontroller Arduino UNO R3 uses the QRS complex peak. Voltage, heart rate, and the QRS complex peak are sent to Android smartphone by Bluetooth HC-05. ECG data is displayed as the graph by Android smartphone. To evaluate the performance of QRS complex peak detection method, three parameters are used; they are positive predictive, accuracy and sensitivity. Positive predictive, accuracy, and sensitivity of Peak Threshold method is 92.39%, 70.30%, 74.62% and for Peak Filter method are 98.38%, 82.47%, 83.61%, respectively.

  10. CT-guided biopsy of pulmonary lesions : a comparison of diagnostic accuracy and complication rate between automated gun biopsy and fine needle aspiration biopsy

    International Nuclear Information System (INIS)

    Kim, Keon Woo; Kang, Duk Sik

    1998-01-01

    The purpose of this study is to compare the efficacy and safety of CT-guided automated gun biopsy with those of fine needle aspiration biopsy of pulmonary lesions. Under CT guidance, we performed automated gu biopsies in 115 cases of 109 patients and fine needle aspiration biopsies in 119 cases of 108 patients with pulmonary lesions. Between the two methods, we compared the diagnostic rate, diagnostic accuracy and frequency of compilations according to the depth and diameter of pulmonary lesions. The overall diagnostic rates of automated gun biopsy and fine needle aspiration biopsy were 76.5 % (88/115) and 64.7 % (77/119) respectively. There was a significant statistical difference (p=0.048), especially in the case of malignant lesions less than 3 cm (p=0.027) and more than 6 cm in maximal diameter (p=0.008), and in the lesions located from 1 cm to less than 3 cm from the pleural (p=0.030), as seen on CT. There was no significant statistical difference in the frequency of complications. Automated gun biopsy of pulmonary lesions under CT guidance is safe, with complications rate comparable to those of fine needle aspiration biopsy. A higher overall diagnostic rate can be achieved by automated gun biopsy than by fine needle aspiration biopsy. For the diagnosis of pulmonary lesions under CT guidance, automated gun biopsy is therefore a more useful procedure than fine needle aspiration biopsy. (author). 24 refs., 3 tabs

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

    Science.gov (United States)

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

    2013-03-01

    Previous research has demonstrated that a parameter extracted from a power function fit to the anatomical noise power spectrum, β, may be predictive of breast mass lesion detectability in x-ray based medical images of the breast. In this investigation, the value of β was compared with a number of other more widely used parameters, in order to determine the relationship between β and these other parameters. This study made use of breast CT data sets, acquired on two breast CT systems developed in our laboratory. A total of 185 breast data sets in 183 women were used, and only the unaffected breast was used (where no lesion was suspected). The anatomical noise power spectrum computed from two-dimensional region of interests (ROIs), was fit to a power function (NPS(f) = α f-β), and the exponent parameter (β) was determined using log/log linear regression. Breast density for each of the volume data sets was characterized in previous work. The breast CT data sets analyzed in this study were part of a previous study which evaluated the receiver operating characteristic (ROC) curve performance using simulated spherical lesions and a pre-whitened matched filter computer observer. This ROC information was used to compute the detectability index as well as the sensitivity at 95% specificity. The fractal dimension was computed from the same ROIs which were used for the assessment of β. The value of β was compared to breast density, detectability index, sensitivity, and fractal dimension, and the slope of these relationships was investigated to assess statistical significance from zero slope. A statistically significant non-zero slope was considered to be a positive association in this investigation. All comparisons between β and breast density, detectability index, sensitivity at 95% specificity, and fractal dimension demonstrated statistically significant association with p performance. Specifically, lower values of β were associated with lower breast density

  12. Detection of occlusal caries lesions using fluorescence: correlation between histology and obtained results for Diagnodent and spectroscopy

    International Nuclear Information System (INIS)

    Rocha-Cabral, Renata Maciel

    2006-01-01

    The aims of this study were to develop and test a method to detect caries lesions in vivo and in vitro, using a portable spectrometer (PS); to analyze the performance of PS as well as the commercial device Diagnodent (Dd); correlate them with the gold standard, their transversal section areas and lesions depth and between themselves. 66 occlusal pre-molars sites were examined in vivo with Dd. Sequentially, fluorescence (λexc ∼ 657 nm) was collected by an optical fiber, conducted to PS and then analyzed as spectra, which were normalized and had calculated the Ratios of their Areas Under the Curves (RAUC) of carious and sound tissues. Experiments were conducted in vitro in the same sites. Gold Standard was obtained by polarized light microscopy. Pearson correlation was used to compare the devices with transversal section area, lesions depth and between themselves. The area under ROC curve, sensitivity, specificity as well as accuracy were calculated and verified with McNemar test. Dd and RAUC showed statistically significant correlation with gold standard (p < 0.01 for Dd and p < 0.05 for RAUC) and between themselves (r = 0,83 in vivo and r = 0,87 in vitro). Although it was significant, the devices showed low correlation with depth of lesions in vivo and in vitro (r = ∼ 0.43). The transversal section area of the lesion had no influence on readings in both devices. Dd showed higher sensitivity (0.76) than PS (0.60) in vivo (p < 0.05), though this fact was not able to improve its performance. In turn, PS showed higher sensitivity (0.88) than Dd (0.79) in vitro, but this difference was not significantly. The other parameters did not show statistically significant differences (p < 0.05) between methods. PS showed positive correlation with Dd, equal correlation with lesions depth and higher ability of detecting the disease in vitro, what suggests that if accompanied with a conic and an angulated probe and a dedicated software, the PS method could be useful in clinics

  13. Globular domain of adiponectin: promising target molecule for detection of atherosclerotic lesions

    Science.gov (United States)

    Almer, Gunter; Saba-Lepek, Matthias; Haj-Yahya, Samih; Rohde, Eva; Strunk, Dirk; Fröhlich, Eleonore; Prassl, Ruth; Mangge, Harald

    2011-01-01

    Background: Adiponectin, an adipocyte-specific plasma protein, has been shown to accumulate in injured endothelial cells during development of atherosclerotic lesions. In this study, we investigated the potential of different adiponectin subfractions with special emphasis on globular adiponectin (gAd) to recognize and visualize atherosclerotic lesions. Methods: Recombinant mouse gAd and subfractions of full-length adiponectin (ie, trimeric, hexameric, and oligomeric forms) were fluorescence-labeled. Aortas of wild-type and apoprotein E-deficient mice fed a high cholesterol diet were dissected and incubated with the labeled biomarkers. Imaging was performed using confocal laser scanning microscopy. Results: Confocal laser scanning microscopic images showed that gAd binds more strongly to atherosclerotic plaques than full-length adiponectin subfractions. Further, we showed that gAd accumulates preferentially in endothelial cells and the fibrous cap area of plaques. Here we demonstrate for the first time that gAd recognizes atherosclerotic plaques on aortic sections of apoprotein E-deficient mice. Conclusion: These results suggest that gAd, in addition to its physiological properties, is also suitable as a target molecule for prospective diagnostic strategies in imaging atherosclerotic lesions. PMID:22022204

  14. Computer-aided detection (CAD) and assessment of malignant lesions in the liver and lung using a novel PET/CT software tool. Initial results

    International Nuclear Information System (INIS)

    Hahn, Steffen; Heusner, T.; Forsting, M.; Antoch, G.; Zhou, X.; Zhan, Y.; Peng, Z.; Hamami, M.; Bockisch, A.

    2010-01-01

    Purpose: To determine the feasibility of a PET/CT software tool (PET computer-aided detection: PET-CAD) for automated detection and assessment of pulmonary and hepatic lesions. Materials and Methods: 20 consecutive patients with colorectal liver metastases and 20 consecutive patients suffering from non-small cell lung cancer (NSCLC) were examined with FDG-PET/CT. In a first step the maximum standardized uptake values (SUV max ) of non-tumorous liver and lung tissues were determined manually. This value was used as a threshold value for software-based lesion detection. The number of lesions detected, their SUV max , and their sizes in the x, y, and z-planes, as automatically provided by PET-CAD, were compared to visual lesion detection and manual measurements on CT. Results: The sensitivity for automated detection was 96% (86-99%) for colorectal liver metastases and 90% (70-99%) for lung lesions. The positive predictive value was 80% for liver and 68% for lung lesions. The mean SUV max of all lung lesions was 9.3 and 8.8 for the liver lesions. When assessed by PET-CAD, the mean lesion sizes for liver lesions in the x, y, and z-planes were 4.3 cm, 4.6 cm, and 4.2 cm compared to 3.5 cm, 3.8 cm, and 3.6 cm for manual measurements. The mean lesion sizes of lung lesions were 7.4 cm, 7.7 cm, and 8.4 cm in the x, y, and z-planes when assessed by PET-CAD compared to 5.8 cm, 6.1 cm, and 7.1 cm when measured manually. Using manual assessment, the lesion sizes were significantly smaller in all planes (p < 0.005). Conclusion: Software tools for automated lesion detection and assessment are expected to improve the clinical PET/CT workflow. Before implementation in the clinical routine, further improvements to the measurement accuracy are required. (orig.)

  15. Influence of attenuation correction and reconstruction techniques on the detection of hypoperfused lesions in brain SPECT studies

    International Nuclear Information System (INIS)

    Ghoorun, S.; Groenewald, W.A.; Baete, K.; Nuyts, J.; Dupont, P.

    2004-01-01

    Full text: Aim: To study the influence of attenuation correction and the reconstruction technique on the detection of hypoperfused lesions in brain SPECT imaging, Material and Methods: A simulation experiment was used in which the effects of attenuation and reconstruction were decoupled, A high resolution SPECT phantom was constructed using the BrainWeb database, In this phantom, activity values were assigned to grey and white matter (ratio 4:1) and scaled to obtain counts of the same magnitude as in clinical practice, The true attenuation map was generated by assigning attenuation coefficients to each tissue class (grey and white matter, cerebral spinal fluid, skull, soft and fatty tissue and air) to create a non-uniform attenuation map, The uniform attenuation map was calculated using an attenuation coefficient of 0.15 cm-1, Hypoperfused lesions of varying intensities and sizes were added. The phantom was then projected as typical SPECT projection data, taking into account attenuation and collimator blurring with the addition of Poisson noise, The projection data was reconstructed using four different methods of reconstruction: (1) filtered backprojection (FBP) with the uniform attenuation map; (2) FBP using the true attenuation map; (3) ordered subset expectation maximization (OSEM) (equivalent to 423 iterations) with a uniform attenuation map; and (4) OSEM with a true attenuation map. Different Gaussian postsmooth kernels were applied to the reconstructed images. Results: The analysis of the reconstructed data was performed using figures of merit such as signal to noise ratio (SNR), bias and variance. The results illustrated that uniform attenuation correction offered slight deterioration (less than 2%) with regard to SNR when compared to the ideal attenuation map. which in reality is not known. The iterative techniques produced superior signal to noise ratios (increase of 5 - 20 % depending on the lesion and the postsmooth) in comparison to the FBP methods

  16. Pipe fracture evaluations for leak-rate detection: Probabilistic models

    International Nuclear Information System (INIS)

    Rahman, S.; Wilkowski, G.; Ghadiali, N.

    1993-01-01

    This is the second in series of three papers generated from studies on nuclear pipe fracture evaluations for leak-rate detection. This paper focuses on the development of novel probabilistic models for stochastic performance evaluation of degraded nuclear piping systems. It was accomplished here in three distinct stages. First, a statistical analysis was conducted to characterize various input variables for thermo-hydraulic analysis and elastic-plastic fracture mechanics, such as material properties of pipe, crack morphology variables, and location of cracks found in nuclear piping. Second, a new stochastic model was developed to evaluate performance of degraded piping systems. It is based on accurate deterministic models for thermo-hydraulic and fracture mechanics analyses described in the first paper, statistical characterization of various input variables, and state-of-the-art methods of modem structural reliability theory. From this model. the conditional probability of failure as a function of leak-rate detection capability of the piping systems can be predicted. Third, a numerical example was presented to illustrate the proposed model for piping reliability analyses. Results clearly showed that the model provides satisfactory estimates of conditional failure probability with much less computational effort when compared with those obtained from Monte Carlo simulation. The probabilistic model developed in this paper will be applied to various piping in boiling water reactor and pressurized water reactor plants for leak-rate detection applications

  17. Recurrence rate and patient satisfaction of CO2 laser evaporation of lesions in patients with hidradenitis suppurativa: a retrospective study.

    Science.gov (United States)

    Mikkelsen, Peter Riis; Dufour, Deirde Nathalie; Zarchi, Kian; Jemec, Gregor B E

    2015-02-01

    Hidradenitis suppurativa (HS) is a debilitating disease and is difficult to treat. Validation of surgical techniques is therefore of great importance in the management of HS. Carbon dioxide (CO2) laser evaporation has been shown effective, but larger-scale studies are scarce. To determine the recurrence rate, time to recurrence, and factors influencing disease recurrence in skin treated with CO2 laser evaporation, and healing by secondary intention; and patients' satisfaction with treatment. Fifty-eight patients treated with CO2 laser evaporation were interviewed regarding recurrence and satisfaction after a mean of 25.7 months. Seventeen of 58 (29%) reported recurrence of HS lesions within the borders of the treated areas after a mean of 12.7 months. Obesity was a risk factor for recurrence with a hazard ratio of 4.53. Fifty-five patients (95%) reported some or great improvement, and 91% would recommend the CO2 laser surgery to other HS patients. This study supports the claim that CO2 laser treatment is an effective modality for recurrent HS lesions in a majority of patients. The authors identified obesity as a risk factor for recurrence. Self-reported satisfaction is high, and only 3 of 58 report no change in the condition. None reported a worsening.

  18. The Problems with the Kappa Statistic as a Metric of Interobserver Agreement on Lesion Detection Using a Third-reader Approach When Locations Are Not Prespecified.

    Science.gov (United States)

    Shih, Joanna H; Greer, Matthew D; Turkbey, Baris

    2018-03-16

    To point out the problems with Cohen kappa statistic and to explore alternative metrics to determine interobserver agreement on lesion detection when locations are not prespecified. Use of kappa and two alternative methods, namely index of specific agreement (ISA) and modified kappa, for measuring interobserver agreement on the location of detected lesions are presented. These indices of agreement are illustrated by application to a retrospective multireader study in which nine readers detected and scored prostate cancer lesions in 163 consecutive patients (n = 110 cases, n = 53 controls) using the guideline of Prostate Imaging Reporting and Data System version 2 on multiparametric magnetic resonance imaging. The proposed modified kappa, which properly corrects for the amount of agreement by chance, is shown to be approximately equivalent to the ISA. In the prostate cancer data, average kappa, modified kappa, and ISA equaled 30%, 55%, and 57%, respectively, for all lesions and 20%, 87%, and 87%, respectively, for index lesions. The application of kappa could result in a substantial downward bias in reader agreement on lesion detection when locations are not prespecified. ISA is recommended for assessment of reader agreement on lesion detection. Published by Elsevier Inc.

  19. Rate of detection of advanced neoplasms in proximal colon by simulated sigmoidoscopy vs fecal immunochemical tests.

    Science.gov (United States)

    Castells, Antoni; Quintero, Enrique; Álvarez, Cristina; Bujanda, Luis; Cubiella, Joaquín; Salas, Dolores; Lanas, Angel; Carballo, Fernando; Morillas, Juan Diego; Hernández, Cristina; Jover, Rodrigo; Hijona, Elizabeth; Portillo, Isabel; Enríquez-Navascués, José M; Hernández, Vicent; Martínez-Turnes, Alfonso; Menéndez-Villalva, Carlos; González-Mao, Carmen; Sala, Teresa; Ponce, Marta; Andrés, Mercedes; Teruel, Gloria; Peris, Antonio; Sopeña, Federico; González-Rubio, Francisca; Seoane-Urgorri, Agustín; Grau, Jaume; Serradesanferm, Anna; Pozo, Àngels; Pellisé, Maria; Balaguer, Francesc; Ono, Akiko; Cruzado, José; Pérez-Riquelme, Francisco; Alonso-Abreu, Inmaculada; Carrillo-Palau, Marta; de la Vega-Prieto, Mariola; Iglesias, Rosario; Amador, Javier; Blanco, José Manuel; Sastre, Rocio; Ferrándiz, Juan; González-Hernández, Ma José; Andreu, Montserrat; Bessa, Xavier

    2014-10-01

    We compared the ability of biennial fecal immunochemical testing (FIT) and one-time sigmoidoscopy to detect colon side-specific advanced neoplasms in a population-based, multicenter, nationwide, randomized controlled trial. We identified asymptomatic men and women, 50-69 years old, through community health registries and randomly assigned them to groups that received a single colonoscopy examination or biennial FIT. Sigmoidoscopy yield was simulated from results obtained from the colonoscopy group, according to the criteria proposed in the UK Flexible Sigmoidoscopy Trial for colonoscopy referral. Patients who underwent FIT and were found to have ≥75 ng hemoglobin/mL were referred for colonoscopy. Data were analyzed from 5059 subjects in the colonoscopy group and 10,507 in the FIT group. The main outcome was rate of detection of any advanced neoplasm proximal to the splenic flexure. Advanced neoplasms were detected in 317 subjects (6.3%) in the sigmoidoscopy simulation group compared with 288 (2.7%) in the FIT group (odds ratio for sigmoidoscopy, 2.29; 95% confidence interval, 1.93-2.70; P = .0001). Sigmoidoscopy also detected advanced distal neoplasia in a higher percentage of patients than FIT (odds ratio, 2.61; 95% confidence interval, 2.20-3.10; P = .0001). The methods did not differ significantly in identifying patients with advanced proximal neoplasms (odds ratio, 1.17; 95% confidence interval, 0.78-1.76; P = .44). This was probably due to the lower performance of both strategies in detecting patients with proximal lesions (sigmoidoscopy detected these in 19.1% of patients and FIT in 14.9% of patients) vs distal ones (sigmoidoscopy detected these in 86.8% of patients and FIT in 33.5% of patients). Sigmoidoscopy, but not FIT, detected proximal lesions in lower percentages of women (especially those 50-59 years old) than men. Sigmoidoscopy and FIT have similar limitations in detecting advanced proximal neoplasms, which depend on patients' characteristics

  20. The impact of noisy and misaligned attenuation maps on human-observer performance at lesion detection in SPECT

    Science.gov (United States)

    Wells, R. G.; Gifford, H. C.; Pretorius, P. H.; Famcombe, T. H.; Narayanan, M. V.; King, M. A.

    2002-06-01

    We have demonstrated an improvement due to attenuation correction (AC) at the task of lesion detection in thoracic SPECT images. However, increased noise in the transmission data due to aging sources or very large patients, and misregistration of the emission and transmission maps, can reduce the accuracy of the AC and may result in a loss of lesion detectability. We investigated the impact of noise in and misregistration of transmission data, on the detection of simulated Ga-67 thoracic lesions. Human-observer localization-receiver-operating-characteristic (LROC) methodology was used to assess performance. Both emission and transmission data were simulated using the MCAT computer phantom. Emission data were reconstructed using OSEM incorporating AC and detector resolution compensation. Clinical noise levels were used in the emission data. The transmission-data noise levels ranged from zero (noise-free) to 32 times the measured clinical levels. Transaxial misregistrations of 0.32, 0.63, and 1.27 cm between emission and transmission data were also examined. Three different algorithms were considered for creating the attenuation maps: filtered backprojection (FBP), unbounded maximum-likelihood (ML), and block-iterative transmission AB (BITAB). Results indicate that a 16-fold increase in the noise was required to eliminate the benefit afforded by AC, when using FBP or ML to reconstruct the attenuation maps. When using BITAB, no significant loss in performance was observed for a 32-fold increase in noise. Misregistration errors are also a concern as even small errors here reduce the performance gains of AC.

  1. Development and psychometric testing of the 'Motivation and Self-Efficacy in Early Detection of Skin Lesions' index.

    Science.gov (United States)

    Dyson, Judith; Cowdell, Fiona

    2014-12-01

    To develop and psychometrically test the Motivation and Self-Efficacy in Early Detection of Skin Lesions Index. Skin cancer is the most frequently diagnosed cancer worldwide. The primary strategy used to prevent skin cancer is promotion of sun avoidance and the use of sun protection. However, despite costly and extensive campaigns, cases of skin cancer continue to increase. If found and treated early, skin cancer is curable. Early detection is, therefore, very important. The study was conducted in 2013. Instrument Development. A literature review and a survey identified barriers (factors that hinder) and levers (factors that help) to skin self-examination. These were categorized according to a the Theoretical Domains Framework and this formed the basis of an instrument, which was tested for validity and reliability using confirmatory factor analysis and Cronbach's alpha respectively. A five-factor 20-item instrument was used that tested well for reliability and construct validity. Test-retest reliability was good for all items and domains. The five factors were: (i) Outcome expectancies; (ii) Intention; (iii) Self-efficacy; (iv) Social influences; (v) Memory. The Motivation and Self-Efficacy in Early Detection of Skin Lesions Index provides a reliable and valid method of assessing barriers and levers to skin self-examination. The next step is to design a theory-based intervention that can be tailored according to individual determinants to behaviour change identified by this instrument. © 2014 John Wiley & Sons Ltd.

  2. The association of colonoscopy quality indicators with the detection of screen-relevant lesions, adverse events, and postcolonoscopy cancers in an asymptomatic Canadian colorectal cancer screening population.

    Science.gov (United States)

    Hilsden, Robert J; Dube, Catherine; Heitman, Steven J; Bridges, Ronald; McGregor, S Elizabeth; Rostom, Alaa

    2015-11-01

    Although several quality indicators of colonoscopy have been defined, quality assurance activities should be directed at the measurement of quality indicators that are predictive of key screening colonoscopy outcomes. The goal of this study was to examine the association among established quality indicators and the detection of screen-relevant lesions (SRLs), adverse events, and postcolonoscopy cancers. Historical cohort study. Canadian colorectal cancer screening center. A total of 18,456 asymptomatic men and women ages 40 to 74, at either average risk or increased risk for colorectal cancer because of a family history, who underwent a screening colonoscopy from 2008 to 2010. Using univariate and multivariate analyses, we explored the association among procedural quality indicators and 3 colonoscopy outcomes: detection of SRLs, adverse events, and postcolonoscopy cancers. The crude rates of SRLs, adverse events, and postcolonoscopy cancers were 240, 6.44, and .54 per 1000 colonoscopies, respectively. Several indicators, including endoscopist withdrawal time (OR, 1.3; 95% CI, 1.2-1.4) and cecal intubation rate (OR, 13.9; 95% CI, 1.9-96.9), were associated with the detection of SRLs. No quality indicator was associated with the risk of adverse events. Endoscopist average withdrawal time over 6 minutes (OR, .12; 95% CI, .002-.85) and SRL detection rate over 20% (OR, .17; 95% CI, .03-.74) were associated with a reduced risk of postcolonoscopy cancers. Single-center study. Quality assurance programs should prioritize the measurement of endoscopist average withdrawal time and adenoma (SRL) detection rate. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  3. Comparision between biphasic helical CT and dynamic gadolinium-enhanced MR in the detection and characterization of focal hepatic lesions in cirrhotic patients

    International Nuclear Information System (INIS)

    Puig, J.; Martin, J.; Donoso, L.; Falco, J.; Rue, M.

    1997-01-01

    To assess the agreement between biphasic helical computerized tomography (BHCT) and dynamic gadolinium-enhanced magnetic resonance (MR) in the detection and characterization of focal hepatic lesions in a group of cirrhotic patients. A prospective study was done in 50 cirrhotic patients suspected of having hepatocarcinoma (HC) on the basis of ultrasonographic images evaluated by means of BHCT and dynamic gadolinium-enhanced MR using fast low-angle shot (FLASH) sequences (110-135/4/90 degree centigree). The images were assessed jointly by four radiologists. Between the two techniques, a total of 83 lesions were detected. MR disclosed more lesions (n=79) than BHCT (n=67) (p<0.005). Moreover, 25 of the lesions that were visible by both techniques were more clearly evident in MR images (p<0.01). MR correctly classified 6 of 7 benign lesions (85%) and 49 of 66 malignant ones (74%). BHCT correctly classifed 2 of 7 benign lesions (28%) and 32 of 66 malignant ones (48%). The sensitivities of MR and BHCT for the characterization of these lesions were 74% and 48%, respectively (p=0.0009), while the respective specificities were 86% and 29% (P<0.001). Dynamic gadolinium-enhanced MR with FLASH sequences is more efficient than BHCT in the detection and characterization of focal lesions in cirrhotic patients. (Author) 37 refs

  4. Utility of fractional anisotropy imaging analyzed by statistical parametric mapping for detecting minute brain lesions in chronic-stage patients who had mild or moderate traumatic brain injury

    International Nuclear Information System (INIS)

    Asano, Yoshitaka; Shinoda, Jun; Okumura, Ayumi; Aki, Tatsuki; Takenaka, Shunsuke; Miwa, Kazuhiro; Yamada, Mikito; Ito, Takeshi; Yokohama, Kazutoshi

    2012-01-01

    Diffusion tensor imaging (DTI) has recently evolved as valuable technique to investigate diffuse axonal injury (DAI). This study examined whether fractional anisotropy (FA) images analyzed by statistical parametric mapping (FA-SPM images) are superior to T 2 *-weighted gradient recalled echo (T2*GRE) images or fluid-attenuated inversion recovery (FLAIR) images for detecting minute lesions in traumatic brain injury (TBI) patients. DTI was performed in 25 patients with cognitive impairments in the chronic stage after mild or moderate TBI. The FA maps obtained from the DTI were individually compared with those from age-matched healthy control subjects using voxel-based analysis and FA-SPM images (p<0.001). Abnormal low-intensity areas on T2*GRE images (T2* lesions) were found in 10 patients (40.0%), abnormal high-intensity areas on FLAIR images in 4 patients (16.0%), and areas with significantly decreased FA on FA-SPM image in 16 patients (64.0%). Nine of 10 patients with T2* lesions had FA-SPM lesions. FA-SPM lesions topographically included most T2* lesions in the white matter and the deep brain structures, but did not include T2* lesions in the cortex/near-cortex or lesions containing substantial hemosiderin regardless of location. All 4 patients with abnormal areas on FLAIR images had FA-SPM lesions. FA-SPM imaging is useful for detecting minute lesions because of DAI in the white matter and the deep brain structures, which may not be visualized on T2*GRE or FLAIR images, and may allow the detection of minute brain lesions in patients with post-traumatic cognitive impairment. (author)

  5. Lesion size detection in geographic atrophy by polarization-sensitive optical coherence tomography and correlation to conventional imaging techniques.

    Science.gov (United States)

    Schütze, Christopher; Bolz, Matthias; Sayegh, Ramzi; Baumann, Bernhard; Pircher, Michael; Götzinger, Erich; Hitzenberger, Christoph K; Schmidt-Erfurth, Ursula

    2013-01-28

    To investigate the reproducibility of automated lesion size detection in patients with geographic atrophy (GA) using polarization-sensitive spectral-domain optical coherence tomography (PS-OCT) and to compare findings with scanning laser ophthalmoscopy (SLO), fundus autofluorescence (FAF), and intensity-based spectral-domain OCT (SD-OCT). Twenty-nine eyes of 22 patients with GA were examined by PS-OCT, selectively identifying the retinal pigment epithelium (RPE). A novel segmentation algorithm was applied, automatically detecting and quantifying areas of RPE atrophy. The reproducibility of the algorithm was assessed, and lesion sizes were correlated with manually delineated SLO, FAF, and intensity-based SD-OCT images to validate the clinical applicability of PS-OCT in GA evaluation. Mean GA lesion size of all patients was 5.28 mm(2) (SD: 4.92) in PS-OCT. Mean variability of individual repeatability measurements was 0.83 mm(2) (minimum: 0.05; maximum: 3.65). Mean coefficient of variation was 0.07 (min: 0.01; max: 0.19). Mean GA area in SLO (Spectralis OCT) was 5.15 mm(2) (SD: 4.72) and 2.5% smaller than in PS-OCT (P = 0.9, Pearson correlation coefficient = 0.98, P < 0.01). Mean GA area in intensity-based SD-OCT pseudo-SLO images (Cirrus OCT) was 5.14 mm(2) (SD: 4.67) and 2.7% smaller than in PS-OCT (P = 0.9, Pearson correlation coefficient = 0.98, P < 0.01). Mean GA area of all eyes measured 5.41 mm(2) (SD: 4.75) in FAF, deviating by 2.4% from PS-OCT results (P = 0.89, Pearson correlation coefficient = 0.99, P < 0.01). PS-OCT demonstrated high reproducibility of GA lesion size determination. Results correlated well with SLO, FAF, and intensity-based SD-OCT fundus imaging. PS-OCT may therefore be a valuable and specific imaging modality for automated GA lesion size determination in scientific studies and clinical practice.

  6. Role of digital tomosynthesis and dual energy subtraction digital radiography in detection of parenchymal lesions in active pulmonary tuberculosis

    International Nuclear Information System (INIS)

    Sharma, Madhurima; Sandhu, Manavjit Singh; Gorsi, Ujjwal; Gupta, Dheeraj; Khandelwal, Niranjan

    2015-01-01

    Highlights: • Digital tomosynthesis and dual energy subtraction digital radiography are modifications of digital radiography. • These modalities perform better than digital radiography in detection of parenchymal lesions in active pulmonary tuberculosis. • Digital tomosynthesis has a sensitivity of 100% in detection of cavities. • Centrilobular nodules seen on CT in active pulmonary tuberculosis, were also demonstrated on digital tomosynthesis in our study. • Digital tomosynthesis can be used for diagnosis and follow up of patients in pulmonary tuberculosis, thereby reducing the number of CT examinations. - Abstract: Objective: To assess the role of digital tomosynthesis (DTS) and dual energy subtraction digital radiography (DES-DR) in detection of parenchymal lesions in active pulmonary tuberculosis (TB) and to compare them with digital radiography (DR). Materials and methods: This prospective study was approved by our institutional review committee. DTS and DES-DR were performed in 62 patients with active pulmonary TB within one week of multidetector computed tomography (MDCT) study. Findings of active pulmonary TB, that is consolidation, cavitation and nodules were noted on digital radiography (DR), DTS and DES-DR in all patients. Sensitivity, specificity, positive and negative predictive values of all 3 modalities was calculated with MDCT as reference standard. In addition presence of centrilobular nodules was also noted on DTS. Results: Our study comprised of 62 patients (33 males, 29 females with age range 18–82 years). Sensitivity and specificity of DTS for detection of nodules and cavitation was better than DR and DES-DR. Sensitivity and specificity of DTS for detection of consolidation was comparable to DR and DES-DR. DES-DR performed better than DR in detection of nodules and cavitation. DTS was also able to detect centrilobular nodules with sensitivity and specificity of 57.4% and 86.5% respectively. Conclusion: DTS and DES-DR perform better

  7. Role of digital tomosynthesis and dual energy subtraction digital radiography in detection of parenchymal lesions in active pulmonary tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Madhurima, E-mail: madhurimashrm88@gmail.com [Department of Radiodiagnosis and Imaging, PGIMER, Chandigarh 160012 (India); Sandhu, Manavjit Singh, E-mail: manavjitsandhu@yahoo.com [Department of Radiodiagnosis and Imaging, PGIMER, Chandigarh 160012 (India); Gorsi, Ujjwal, E-mail: ujjwalgorsi@gmail.com [Department of Radiodiagnosis and Imaging, PGIMER, Chandigarh 160012 (India); Gupta, Dheeraj, E-mail: dheeraj1910@gmail.com [Department of Pulmonary Medicine, PGIMER, Chandigarh 160012 (India); Khandelwal, Niranjan, E-mail: khandelwaln@hotmail.com [Department of Radiodiagnosis and Imaging, PGIMER, Chandigarh 160012 (India)

    2015-09-15

    Highlights: • Digital tomosynthesis and dual energy subtraction digital radiography are modifications of digital radiography. • These modalities perform better than digital radiography in detection of parenchymal lesions in active pulmonary tuberculosis. • Digital tomosynthesis has a sensitivity of 100% in detection of cavities. • Centrilobular nodules seen on CT in active pulmonary tuberculosis, were also demonstrated on digital tomosynthesis in our study. • Digital tomosynthesis can be used for diagnosis and follow up of patients in pulmonary tuberculosis, thereby reducing the number of CT examinations. - Abstract: Objective: To assess the role of digital tomosynthesis (DTS) and dual energy subtraction digital radiography (DES-DR) in detection of parenchymal lesions in active pulmonary tuberculosis (TB) and to compare them with digital radiography (DR). Materials and methods: This prospective study was approved by our institutional review committee. DTS and DES-DR were performed in 62 patients with active pulmonary TB within one week of multidetector computed tomography (MDCT) study. Findings of active pulmonary TB, that is consolidation, cavitation and nodules were noted on digital radiography (DR), DTS and DES-DR in all patients. Sensitivity, specificity, positive and negative predictive values of all 3 modalities was calculated with MDCT as reference standard. In addition presence of centrilobular nodules was also noted on DTS. Results: Our study comprised of 62 patients (33 males, 29 females with age range 18–82 years). Sensitivity and specificity of DTS for detection of nodules and cavitation was better than DR and DES-DR. Sensitivity and specificity of DTS for detection of consolidation was comparable to DR and DES-DR. DES-DR performed better than DR in detection of nodules and cavitation. DTS was also able to detect centrilobular nodules with sensitivity and specificity of 57.4% and 86.5% respectively. Conclusion: DTS and DES-DR perform better

  8. Joint line tenderness and McMurray tests for the detection of meniscal lesions: what is their real diagnostic value?

    Science.gov (United States)

    Galli, Marco; Ciriello, Vincenzo; Menghi, Amerigo; Aulisa, Angelo G; Rabini, Alessia; Marzetti, Emanuele

    2013-06-01

    To assess the interobserver concordance of the joint line tenderness (JLT) and McMurray tests, and to determine their diagnostic efficiency for the detection of meniscal lesions. Prospective observational study. Orthopedics outpatient clinic, university hospital. Patients (N=60) with suspected nonacute meniscal lesions who underwent knee arthroscopy. Not applicable. Patients were examined by 3 independent observers with graded levels of experience (>10y, 3y, and 4mo of practice). The interobserver concordance was assessed by Cohen-Fleiss κ statistics. Accuracy, negative and positive predictive values for prevalence 10% to 90%, positive (LR+) and negative (LR-) likelihood ratios, and the Bayesian posttest probability with a positive or negative result were also determined. The diagnostic value of the 2 tests combined was assessed by logistic regression. Arthroscopy was used as the reference test. No interobserver concordance was determined for the JLT. The McMurray test showed higher interobserver concordance, which improved when judgments by the less experienced examiner were discarded. The whole series studied by the "best" examiner (experienced orthopedist) provided the following values: (1) JLT: sensitivity, 62.9%; specificity, 50%; LR+, 1.26; LR-, .74; (2) McMurray: sensitivity, 34.3%; specificity, 86.4%; LR+, 2.52; LR-, .76. The combination of the 2 tests did not offer advantages over the McMurray alone. The JLT alone is of little clinical usefulness. A negative McMurray test does not modify the pretest probability of a meniscal lesion, while a positive result has a fair predictive value. Hence, in a patient with a suspected meniscal lesion, a positive McMurray test indicates that arthroscopy should be performed. In case of a negative result, further examinations, including imaging, are needed. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  9. The value of digital tomosynthesis of the chest as a problem-solving tool for suspected pulmonary nodules and hilar lesions detected on chest radiography.

    Science.gov (United States)

    Galea, Angela; Dubbins, Paul; Riordan, Richard; Adlan, Tarig; Roobottom, Carl; Gay, David

    2015-05-01

    To assess the capability of digital tomosynthesis (DTS) of the chest compared to a postero-anterior (PA) and lateral chest radiograph (CXR) in the diagnosis of suspected but unconfirmed pulmonary nodules and hilar lesions detected on a CXR. Computed tomography (CT) was used as the reference standard. 78 patients with suspected non-calcified pulmonary nodules or hilar lesions on their CXR were included in the study. Two radiologists, blinded to the history and CT, prospectively analysed the CXR (PA and lateral) and the DTS images using a picture archiving and communication workstation and were asked to designate one of two outcomes: true intrapulmonary lesion or false intrapulmonary lesion. A CT of the chest performed within 4 weeks of the CXR was used as the reference standard. Inter-observer agreement and time to report the modalities were calculated for CXR and DTS. There were 34 true lesions confirmed on CT, 12 were hilar lesions and 22 were peripheral nodules. Of the 44 false lesions, 37 lesions were artefactual or due to composite shadow and 7 lesions were real but extrapulmonary simulating non-calcified intrapulmonary lesions. The PA and lateral CXR correctly classified 39/78 (50%) of the lesions, this improved to 75/78 (96%) with DTS. The sensitivity and specificity was 0.65 and 0.39 for CXR and 0.91 and 1 for DTS. Based on the DTS images, readers correctly classified all the false lesions but missed 3/34 true lesions. Two of the missed lesions were hilar in location and one was a peripheral nodule. All three missed lesions were incorrectly classified on DTS as composite shadow. DTS improves diagnostic confidence when compared to a repeat PA and lateral CXR in the diagnosis of both suspected hilar lesions and pulmonary nodules detected on CXR. DTS is able to exclude most peripheral pulmonary nodules but caution and further studies are needed to assess its ability to exclude hilar lesions. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Cone-beam computed tomography versus digital periapical radiography in the detection of artificially created periapical lesions: A pilot study of the diagnostic accuracy of endodontists using both techniques

    Energy Technology Data Exchange (ETDEWEB)

    Campello, Abdrea Fagundes; Goncalves, Lucio Souza; Marques, Fabio vidal [Faculty of Dentistry, Estacio de Sa University, Rio de Janeiro (Brazil); Guedes, Fabio Ribeiro [Faculty of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil)

    2017-03-15

    The aim of this study was to compare the diagnostic accuracy of previously trained endodontists in the detection of artificially created periapical lesions using cone-beam computed tomography (CBCT) and digital periapical radiography (DPR). An ex vivo model using dry skulls was used, in which simulated apical lesions were created and then progressively enlarged using no.1/2, no.2, no.4, and no.6 round burs. A total of 11 teeth were included in the study, and 110 images were obtained with CBCT and with an intraoral digital periapical radiographic sensor (Instrumentarium dental, Tuusula, Finland) initially and after each bur was used. Specificity and sensitivity were calculated. All images were evaluated by 10 previously trained, certified endodontists. Agreement was calculated using the kappa coefficient. The accuracy of each method in detecting apical lesions was calculated using the chi-square test. The kappa coefficient between examiners showed low agreement (range, 0.17-0.64). No statistical difference was found between CBCT and DPR in teeth without apical lesions (P=.15). The accuracy for CBCT was significantly higher than for DPR in all corresponding simulated lesions (P<.001). The correct diagnostic rate for CBCT ranged between 56.9% and 73.6%. The greatest difference between CBCT and DPR was seen in the maxillary teeth (CBCT, 71.4%; DPR, 28.6%; P<.01) and multi-rooted teeth (CBCT, 83.3%; DPR, 33.3%; P<.01). CBCT allowed higher accuracy than DPR in detecting simulated lesions for all simulated lesions tested. Endodontists need to be properly trained in interpreting CBCT scans to achieve higher diagnostic accuracy.

  11. Detection of mouse endogenous type B astrocytes migrating towards brain lesions

    Directory of Open Access Journals (Sweden)

    Gema Elvira

    2015-01-01

    Full Text Available Neuroblasts represent the predominant migrating cell type in the adult mouse brain. There are, however, increasing evidences of migration of other neural precursors. This work aims at identifying in vivo endogenous early neural precursors, different from neuroblasts, able to migrate in response to brain injuries. The monoclonal antibody Nilo1, which unequivocally identifies type B astrocytes and embryonic radial glia, was coupled to magnetic glyconanoparticles (mGNPs. Here we show that Nilo1–mGNPs in combination with magnetic resonance imaging in living mice allowed the in vivo identification of endogenous type B astrocytes at their niche, as well as their migration to the lesion site in response to glioblastoma, demyelination, cryolesion or mechanical injuries. In addition, Nilo1+ adult radial glia-like structures were identified at the lesion site a few hours after damage. For all damage models used, type B astrocyte migration was fast and orderly. Identification of Nilo1+ cells surrounding an induced glioblastoma was also possible after intraperitoneal injection of the antibody. This opens up the possibility of an early identification of the initial damage site(s after brain insults, by the migration of type B astrocytes.

  12. High mid-term revision rate after treatment of large, full-thickness cartilage lesions and OA in the patellofemoral joint using a large inlay resurfacing prosthesis

    DEFF Research Database (Denmark)

    Laursen, Jens Ole

    2017-01-01

    PURPOSE: The HemiCAP-Wave® implant for the patellofemoral resurfacing treatment of large cartilage lesions and osteoarthritis (OA) was introduced in 2009. The outcome of a prospective cohort study of 18 patients with large trochlea lesions or isolated OA treated with the HemiCAP-Wave® implant...... pain but high mid-term revision rate after patellofemoral inlay resurfacing using the HemiCAP-Wave® implant. Patellofemoral resurfacing implantation treatment with a large inlay prosthesis can offer temporary treatment for large isolated patellofemoral cartilage lesions or OA in younger patients...

  13. 99m Tc-MIP-1404-SPECT/CT for the detection of PSMA-positive lesions in 225 patients with biochemical recurrence of prostate cancer.

    Science.gov (United States)

    Schmidkonz, Christian; Hollweg, Claudia; Beck, Michael; Reinfelder, Julia; Goetz, Theresa I; Sanders, James C; Schmidt, Daniela; Prante, Olaf; Bäuerle, Tobias; Cavallaro, Alexander; Uder, Michael; Wullich, Bernd; Goebell, Peter; Kuwert, Torsten; Ritt, Philipp

    2018-01-01

    99m Tc-MIP-1404 (Progenics Pharmaceuticals, Inc., New York, NY) is a novel, SPECT-compatible 99m Tc-labeled PSMA inhibitor for the detection of prostate cancer. We present results of its clinical use in a cohort of 225 men with histologically confirmed prostate cancer referred for workup of biochemical relapse. From April 2013 to April 2017, 99m Tc-MIP1404-scintigraphy was performed in 225 patients for workup of PSA biochemical relapse of prostate cancer. Whole-body planar and SPECT/CT images of the lower abdomen and thorax were obtained 3-4 h p.i. of 710 ± 64 MBq 99m Tc-MIP-1404. Images were visually analyzed for presence and location of abnormal uptake. In addition, quantitative analysis of the SPECT/CT data was carried out on a subset of 125 patients. Follow-up reports of subsequent therapeutic interventions were available for 59% (139) of all patients. Tracer-positive lesions were detected in 77% (174/225) of all patients. Detections occurred at the area of local recurrence in the prostate in 25% of patients (or a total of 56), with metastases in lymph nodes in 47% (105), bone in 27% (60), lung in 5% (12), and other locations in 2% (4) of patients. Detection rates were 90% at PSA levels ≥2 ng/mL and 54% below that threshold. Lesional SUVmax values were, on average, 32.2 ± 29.6 (0.8-142.2), and tumor-to-normal ratios 146.6 ± 160.5 (1.9-1482.4). The PSA level correlated significantly with total uptake of MIP-1404 in tumors (P Tc-MIP-1404-imaging and other information, an interdisciplinary tumor board review recommended changes to treatment plans in 74% (104/139) of those patients for whom the necessary documentation was available. SPECT/CT with 99m Tc-labeled MIP-1404 has a high probability in detecting PSMA-positive lesions in patients with elevated PSA. Statistical analysis disclosed significant relationship between quantitative 99m Tc-MIP-1404 uptake, PSA level, and Gleason score. © 2017 Wiley Periodicals, Inc.

  14. Improved detection and biopsy of solid liver lesions using pulse-inversion ultrasound scanning and contrast agent infusion

    DEFF Research Database (Denmark)

    Skjoldbye, B.; Pedersen, Morten Høgholm; Struckmann, J.

    2002-01-01

    The purpose of this study was to assess the ability of pulse-inversion ultrasound (US) scanning (PIUS), combined with an IV contrast agent, to detect malignant liver lesions and its impact on patient management (resectability). Additionally, to determine the feasibility of US-guided biopsy of new...... PIUS-findings at the same session. A total of 30 patients with known or clinically suspected cancer underwent conventional B-mode scanning and PIUS with IV-administered contrast agent. The number of liver metastases in the right and the left liver lobe, respectively, was recorded. All patients...... findings were performed in 17 of 18 patients. All biopsies of additional findings confirmed malignancy. PIUS with an IV contrast agent increased the ability to detect liver metastases compared to conventional US scanning. The technique had a high impact on patient management. The results showed that PIUS...

  15. Differences in the location and activity of intestinal Crohn's disease lesions between adult and paediatric patients detected with MRI

    International Nuclear Information System (INIS)

    Maccioni, Francesca; Carrozzo, Federica; Pino, Anna Rosaria; Staltari, Ilaria; Ansari, Najwa Al; Marini, Mario; Viola, Franca; Di Nardo, Giovanni; Cucchiara, Salvatore; Vestri, Annarita; Signore, Alberto

    2012-01-01

    To prospectively compare paediatric patients (PP) and adult patients (AP) affected by Crohn's disease (CD) in terms of the location and activity of intestinal lesions. Forty-three children (mean age 15 years) and 43 adults (mean age 48 years) with proven CD underwent magnetic resonance enterography (MRE) to localise lesions and detect their activity in 9 segments of the small and large bowel. The results were analysed on a per patient and per segment basis. Ileo-colonoscopy was performed in all patients. P values less than 0.05 were considered statistically significant. Involvement of terminal ileum was significantly different in the two groups: observed in 100 % of AP (43/43) versus 58 % (23/43) of PP (P < 0.0001). Conversely, the colon was diseased in 84 % of PP versus 64 % of AP. In particular, left colonic segments were significantly more involved in PP (descending colon 53 % versus 21 %, P < 0.01; rectum 67 % versus 23 %, P < 0.0001; sigmoid colon 56 % versus 37 %, not significant), whereas caecal involvement was equal in both groups. In children the maximal disease activity was found in left colonic segments, whereas in adults it was in the terminal ileum. MRE detected significant differences between the two populations, showing a more extensive and severe involvement of the left colon in children but the distal ileum in adults. (orig.)

  16. Detection of human papillomavirus in nonmelanoma skin cancer lesions and healthy perilesional skin in kidney transplant recipients and immunocompetent patients.

    Science.gov (United States)

    Bernat-García, J; Morales Suárez-Varela, M; Vilata-Corell, J J; Marquina-Vila, A

    2014-04-01

    The influence of human papillomavirus (HPV) on the development of nonmelanoma skin cancer (NMSC) is a topic of debate. HPV types from the beta genus (HPV-β) have been most frequently associated with the development of skin cancer. To analyze the prevalence and range of HPV types in NMSC lesions and healthy perilesional skin in immunodepressed and immunocompetent patients and to evaluate the influence of various clinical factors on the prevalence of HPV in skin cancer. Nested polymerase chain reaction and sequencing were used to detect HPV in 120 NMSC samples obtained by biopsy from 30 kidney transplant recipients and 30 immunocompetent patients. In all cases, a sample was taken from the tumor site and the surrounding healthy skin. Potential confounders were assessed and the data analyzed by multivariate logistic regression. HPV DNA was detected in 44 (73.3%) of the 60 samples from immunodepressed patients and in 32 (53.3%) of the 60 samples from immunocompetent patients (adjusted odds ratio, 3.4; 95% CI, 1.2-9.6). In both groups of patients, HPV was more common in healthy perilesional skin than in lesional skin. HPV-β was the most common type isolated. We found a wide range of HPV types (mostly HPV-β) in the skin of kidney transplant recipients and immunocompetent patients with skin cancer. Copyright © 2013 Elsevier España, S.L. and AEDV. All rights reserved.

  17. Screening colonoscopy for the detection of neoplastic lesions in asymptomatic HIV-infected subjects.

    Science.gov (United States)

    Bini, E J; Green, B; Poles, M A

    2009-08-01

    Although non-AIDS defining malignancies are rapidly increasing as HIV-infected subjects live longer, little is know about the results of screening for colonic neoplasms (adenomatous polyps and adenocarcinomas) in this population. We conducted a screening colonoscopy study to determine the prevalence of colonic neoplasms in 136 asymptomatic HIV-infected subjects >or=50 years of age and 272 asymptomatic uninfected control subjects matched for age, sex, and family history of colorectal cancer. Advanced neoplasms were defined as adenomas >or=10 mm or any adenoma, regardless of size, with villous histology, high-grade dysplasia, or adenocarcinoma. The prevalence of neoplastic lesions was significantly higher in HIV-infected subjects than in control subjects (62.5% vs 41.2%, pscreening colonoscopy should be offered to HIV-infected subjects, but the age of initiation and the optimal frequency of screening require further study.

  18. Use of 99mTc mercaptoacetyltriglycine (MAG3) for detection of renal lesions after ESWL

    International Nuclear Information System (INIS)

    Schaub, T.; Witsch, U.; El-Damanhoury, H.; Naegele-Woehrle, B.; Hahn, K.

    1992-01-01

    Extracorporeal shock wave lithotripsy (ESWL) has become the treatment of choice for urinary calculi. 117 patients were studied prospectively with 99m Tc Mercaptoacetyltriglycine (MAG3) before and after ESWL. 79 (66%) of the 119 kidneys treated had abnormal findings. Of these 63/119 (53%) had abnormal scans. 41 (65%) had focal lesions with a delayed intrarenal transport. The remaining 22 had a diffuse delay of intrarenal transport. A loss of relative renal function of 3% and more compared to the pretreatment values was observed in 50/119 (42%) patients. 99m Tc MAG3 should be done routinely together with radiologic tests (CT or MRI) before and after ESWL to select the patients at risk for post ESWL hypertension. (orig.) [de

  19. mHealth App for Risk Assessment of Pigmented and Nonpigmented Skin Lesions-A Study on Sensitivity and Specificity in Detecting Malignancy.

    Science.gov (United States)

    Thissen, Monique; Udrea, Andreea; Hacking, Michelle; von Braunmuehl, Tanja; Ruzicka, Thomas

    2017-12-01

    With the advent of smartphone devices, an increasing number of mHealth applications that target melanoma identification have been developed, but none addresses the general context of melanoma and nonmelanoma skin cancer identification. In this study a smartphone application using fractal and classical image analysis for the risk assessment of skin lesions is systematically evaluated to determine its sensitivity and specificity in the diagnosis of melanoma and nonmelanoma skin cancer along with actinic keratosis and Bowen's disease. In the Department of Dermatology, Catharina Hospital Eindhoven, The Netherlands, 341 melanocytic and nonmelanocytic lesions were imaged using SkinVision app; 239 underwent histopathological examination, while the rest of 102 lesions were clinically diagnosed as clearly benign and not removed. The algorithm has been calibrated using the images of the first 233 lesions. The calibrated version of the algorithm was used in a subset of 108 lesions, and the obtained results were compared with the medical findings. On the 108 cases used for evaluation the algorithm scored 80% sensitivity and 78% specificity in detecting (pre)malignant conditions. Although less accurate than the dermatologist's clinical eye, the app may offer support to other professionals who are less familiar with differentiating between benign and malignant lesions. An mHealth application for the risk assessment of skin lesions was evaluated. It adds value to diagnosis tools of its type by taking into consideration pigmented and nonpigmented lesions all together and detecting signs of malignancy with high sensitivity.

  20. A novel method based on learning automata for automatic lesion detection in breast magnetic resonance imaging.

    Science.gov (United States)

    Salehi, Leila; Azmi, Reza

    2014-07-01

    Breast cancer continues to be a significant public health problem in the world. Early detection is the key for improving breast cancer prognosis. In this way, magnetic resonance imaging (MRI) is emerging as a powerful tool for the detection of breast cancer. Breast MRI presently has two major challenges. First, its specificity is relatively poor, and it detects many false positives (FPs). Second, the method involves acquiring several high-resolution image volumes before, during, and after the injection of a contrast agent. The large volume of data makes the task of interpretation by the radiologist both complex and time-consuming. These challenges have led to the development of the computer-aided detection systems to improve the efficiency and accuracy of the interpretation process. Detection of suspicious regions of interests (ROIs) is a critical preprocessing step in dynamic contrast-enhanced (DCE)-MRI data evaluation. In this regard, this paper introduces a new automatic method to detect the suspicious ROIs for breast DCE-MRI based on region growing. The results indicate that the proposed method is thoroughly able to identify suspicious regions (accuracy of 75.39 ± 3.37 on PIDER breast MRI dataset). Furthermore, the FP per image in this method is averagely 7.92, which shows considerable improvement comparing to other methods like ROI hunter.

  1. Exposure (mAs) optimisation of a multi-detector CT protocol for hepatic lesion detection: are thinner slices better?

    International Nuclear Information System (INIS)

    Dobeli, Karen L.; Lewis, Sarah J.; Meikle, Steven R.; Brennan, Patrick C.; Thiele, David L.

    2014-01-01

    The purpose of this work was to determine the exposure-optimised slice thickness for hepatic lesion detection with CT. A phantom containing spheres (diameter 9.5, 4.8 and 2.4mm) with CT density 10 HU below the background (50 HU) was scanned at 125, 100, 75 and 50 mAs. Data were reconstructed at 5-, 3- and 1-mm slice thicknesses. Noise, contrast-to-noise ratio (CNR), area under the curve (AUC) as calculated using receiver operating characteristic analysis and sensitivity representing lesion detection were calculated and compared. Compared with the 125 mAs/5mm slice thickness setting, significant reductions in AUC were found for 75 mAs (P<0.01) and 50 mAs (P<0.05) at 1- and 3-mm thicknesses, respectively; sensitivity for the 9.5-mm sphere was significantly reduced for 75 (P<0.05) and 50 mAs (P<0.01) at 1-mm thickness; sensitivity for the 4.8-mm sphere was significantly lower for 100, 75 and 50 mAs at all three slice thicknesses (P<0.05). The 2.4-mm sphere was rarely detected. At each slice thickness, noise at 100, 75 and 50 mAs exposures was approximately 10, 30 and 50% higher, respectively, than that at 125 mAs exposure. CNRs decreased in an irregular manner with reductions in exposure and slice thickness. This study demonstrated no advantage to using slices below 5mm thickness, and consequently thinner slices are not necessarily better.

  2. Computer aided detection in prostate cancer diagnostics: A promising alternative to biopsy? A retrospective study from 104 lesions with histological ground truth.

    Directory of Open Access Journals (Sweden)

    Anika Thon

    Full Text Available Prostate cancer (PCa diagnosis by means of multiparametric magnetic resonance imaging (mpMRI is a current challenge for the development of computer-aided detection (CAD tools. An innovative CAD-software (Watson Elementary™ was proposed to achieve high sensitivity and specificity, as well as to allege a correlate to Gleason grade.To assess the performance of Watson Elementary™ in automated PCa diagnosis in our hospital´s database of MRI-guided prostate biopsies.The evaluation was retrospective for 104 lesions (47 PCa, 57 benign from 79, 64.61±6.64 year old patients using 3T T2-weighted imaging, Apparent Diffusion Coefficient (ADC maps and dynamic contrast enhancement series. Watson Elementary™ utilizes signal intensity, diffusion properties and kinetic profile to compute a proportional Gleason grade predictor, termed Malignancy Attention Index (MAI. The analysis focused on (i the CAD sensitivity and specificity to classify suspect lesions and (ii the MAI correlation with the histopathological ground truth.The software revealed a sensitivity of 46.80% for PCa classification. The specificity for PCa was found to be 75.43% with a positive predictive value of 61.11%, a negative predictive value of 63.23% and a false discovery rate of 38.89%. CAD classified PCa and benign lesions with equal probability (P 0.06, χ2 test. Accordingly, receiver operating characteristic analysis suggests a poor predictive value for MAI with an area under curve of 0.65 (P 0.02, which is not superior to the performance of board certified observers. Moreover, MAI revealed no significant correlation with Gleason grade (P 0.60, Pearson´s correlation.The tested CAD software for mpMRI analysis was a weak PCa biomarker in this dataset. Targeted prostate biopsy and histology remains the gold standard for prostate cancer diagnosis.

  3. Molecular detection of Chlamydia Trachomatis and Mycoplasma Hominis in endometriosis lesions

    Directory of Open Access Journals (Sweden)

    F. Azizvakili

    2016-12-01

    Full Text Available Background: Retrograde of menstrual blood into the peritoneal cavity is one of the accepted theories for initiation of endometriosis although indicated that other factors are involved in pathogenesis. Investigation of infectious agents is important in this regard. Objective: To investigate the presence of bacterial infections; Chlamydia trachomatis and Mycoplasma Hominis as risk factors in endometriosis lesions. Methods: This case-control study was conducted in Sarem Hospital in 2014. DNA was extracted from 90 paraffin-embedded blocks included 40 endometriosis tissue samples, 23 samples of endometrial tissue from the same patients and 27 samples of endometrial tissue of the patients without endometriosis, and molecular analysis were performed using polymerase chain reaction. Results were analyzed by Fisher Exact Test and McNemar Test. Findings: Chlamydia trachomatis infection was seen in 11 (27.5% endometriosis tissue, 3 (13% normal tissue from patients and 10 (37% in patient without endometriosis. Mycoplasma hominis was diagnosed in 11 (27.5% endometriosis tissue, 7 (30.4% of normal tissue from patients and one patient without endometriosis (3.7%. These differences show significant relations between infection with Mycoplasma hominis and endometriosis. Conclusion: The findings of this study did not show significant association between Chlamydia trachomatis infections and endometriosis. However; it seems Mycoplasma hominis infection can increase the risk of endometriosis incidence.

  4. FDG-PET/CT detection of very early breast cancer in women with breast microcalcification lesions found in mammography screening

    International Nuclear Information System (INIS)

    Peng, Nang-Jing; Chou, Chen-Pin; Pan, Huay-Ben; Chang, Tsung-Hsien; Hu, Chin; Chiu, Yu-Li; Fu, Ting-Ying; Chang, Hong-Tai

    2015-01-01

    To assess the efficacy of positron emission tomography/computed tomography with the glucose analogue 2-[ 18 F]fluoro-2-deoxy-D-glucose (FDG-PET/CT) in Taiwanese women with early breast cancer detected by mammography screening. Dual-time-point imaging of whole-body supine and breast prone scans using FDG-PET/CT were performed sequentially in the pre-operative stage. A total of 11,849 patients underwent screening mammography, of whom 1,209 (10.2%) displayed positive results. After further investigation, 54 patients underwent FDG-PET/CT. Post-operative pathology examinations revealed malignancies in 26 lesions, including invasive breast cancer in 11 cases and non-invasive breast cancer in 15 cases, as well as benign disease in 30 lesions. The FDG-PET/CT findings from the whole-body scans were positive for 9 of 11 invasive breast cancers (81.8%) and 3 of 15 non-invasive cancers (20%), and they were negative for all benign lesions. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of FDG-PET/CT with whole-body supine imaging were 46.2%, 100%, 100% and 68.2%, respectively. Breast prone imaging revealed another patient with ductal carcinoma in situ, increasing the sensitivity to 50%. Importantly, positive PET findings were significantly correlated with tumour histology (P = 0.006), tumour size (P = 0.039) and Ki-67 expression (P = 0.011). FDG-PET/CT with whole-body scanning demonstrated high sensitivity to invasive breast cancer, limited sensitivity to non-invasive breast cancer, and high specificity for breast cancer. FDG-PET/CT might be useful for differentiating tumour invasiveness. However, the good PPV but poor NPV do not allow the physician to discard the biopsy.

  5. Comparison of carbon dioxide and argon euthanasia: effects on behavior, heart rate, and respiratory lesions in rats.

    Science.gov (United States)

    Burkholder, Tanya H; Niel, Lee; Weed, James L; Brinster, Lauren R; Bacher, John D; Foltz, Charmaine J

    2010-07-01

    In this study we compared rat (n = 16) responses to euthanasia with either gradual-fill CO(2) or rapid induction argon gas by evaluating the animals' heart rate via radiotelemetry, behavior, and vocalizations. We also evaluated the histologic effects of the gases. Rats were placed in an open test chamber 24 h before the start of the experiment. During baseline tests, rats were exposed to oxygen to evaluate the effects of the noise and movement of gas entering the chamber; 1 wk later, rats were euthanized by gas displacement with either 10%/min CO(2) or 50%/min argon gas. Rats tended to have higher heart rats and were more active during the baseline test, but these parameters were normal before the euthanasia experiment, suggesting that the rats had acclimated to the equipment. Heart rate, behavior, and ultrasonic vocalizations were recorded for 2 min after gas introduction in both groups. All rats appeared conscious throughout the test interval. The heart rates of rats exposed to argon did not change, whereas those of rats exposed to CO(2) declined significantly. Unlike those exposed to CO(2), rats euthanized with argon gas gasped and demonstrated seizure-like activity. There were no differences in the pulmonary lesions resulting from death by either gas. Our results suggest that argon as a sole euthanasia agent is aversive to rats. CO(2) using a 10%/min displacement may be less aversive than more rapid displacements. Future research investigating methods of euthanasia should allow sufficient time for the rats to acclimate to the test apparatus.

  6. A qualitative study examining the experience of primary care dentists in the detection and management of potentially malignant lesions. 1. Factors influencing detection and the decision to refer.

    Science.gov (United States)

    Brocklehurst, P R; Baker, S R; Speight, P M

    2010-01-23

    Many oral squamous cell carcinomas present as late stage disease and so the detection of early and pre-malignancy is considered to be of paramount importance. The majority of research examining primary care dentists' experience of the detection and management of early disease has been undertaken using questionnaires, with the inherent bias this introduces. The aim of this study was to use qualitative methods to develop a richer account of practitioners' views about screening and what factors influence the decision to refer a patient. Semi-structured interviews were undertaken with eighteen dentists in Sheffield, transcribed and analysed using thematic analysis. Ten codes were identified according to the aims of the study and organized into four overarching themes. Although many dentists were screening regularly, some did not appear to be adopting a rigorous and systematic approach. A number of participants also placed more reliance on 'classical' presentations rather than the more varied presentation of potentially malignant lesions and were more influenced by the clinical history of the lesion rather than risk factors. Overall, the present research suggests that for some dentists, more rigour is required when examining for early disease.

  7. Detection of fat in focal liver lesions using chemical-shift MR imaging: its significance in patients with and without hepatic cirrhosis

    International Nuclear Information System (INIS)

    Martin, J.

    1999-01-01

    To determine the utility of the chemical shift technique in MRI for the detection of fact in focal hepatic lesions and to see its significance in patients with and without hepatic cirrhosis. 159 patients with 207 hepatic lesions were studied using MRI (IT). Two groups were established: a) patients with hepatic cirrhosis (n=63 with 69 lesions) and b) patients without cirrhosis (n=96 with 138 lesions). Images were obtained in phase (P) and in opposite phase (OP) with gradient echo sequences (RG). The parameter used to differentiate the lesions with fat from those without fat was the variation percentage of the intensity of the signal (VIS) between the images in P and in OP. The statistical valuation was carried out using Student's t tests and the area under the ROC curve. The chemical shift technique detected fat in 25 lesions (12%), 10 hepatocarcinomas in the patients with cirrhosis and two angiomyolipomas and 13 nodular fat infiltrations in the patients who did not have cirrhosis. The average VIS percentage in the 10 hepatocarcinomas was 174.77% (ranging from 88.64% to 369.33%) while in the remaining 59 hepatocarcinomas it was -4.03% (ranging from 12.79% to -19.10%) (p=0.003). In the patients who did not have cirrhosis the average VIS percentage of the lesions with fat was 161.23 (ranging from 19.82 to 605.78) while in the lesions without fat it was -0.41 (ranging from -18.96 to 19.52) (p=0.003). The area under the ROC curve was 1 for the VIS parameter. The chemical shift technique allowed for fat to be detected within hepatic lesions. Based on our study, a nodule with fat in a patient with hepatic cirrhosis is suspected to have hepatocarcinomas while in patients who do not suffer from cirrhosis the existence of fat in a nodule favours its bening nature. (Author) 39 refs

  8. Detectability and detection rate of acute cerebral hemisphere infarcts on CT and diffusion-weighted MRI

    International Nuclear Information System (INIS)

    Urbach, H.; Flacke, S.; Keller, E.; Textor, J.; Berlis, A.; Reul, J.; Schild, H.H.; Hartmann, A.; Solymosi, L.

    2000-01-01

    Our purpose was to compare the detectability and detection rate of acute ischaemic cerebral hemisphere infarcts on CT and diffusion-weighted MRI (DWI). We investigated 32 consecutive patients with acute hemisphere stroke with unenhanced CT and DWI within 6 h of stroke onset. The interval between CT and DWI ranged from 15 to 180 min (mean 60 min). Infarct detectability on CT and DWI was determined by comparing the initial CT, DWI and later reference images in a consensus reading of five independent examiners. The ''true'' detection rate was assessed by analysing all single readings. Two patients had intracerebral haematomas on DWI and CT and were excluded. There were 27 patients with ischaemic infarcts; all were visible on DWI and proven by follow-up. DWI was negative in three patients without a final diagnosis of infarct (100 % sensitivity, 100 % specificity, χ 2 = 30, P 2 = 1.48, P = 0.224). With regard to the single readings (30 examinations x 5 examiners = 150 readings), 63 CT readings were true positive and 72 false negative (sensitivity 47 %, specificity 86 %, χ 2 = 2.88, P = 0.089). Of the DWI readings 128 were true positive and 7 false negative (sensitivity 95 %, specificity 87 %, χ 2 = 70.67, P < 0.0001). Interobserver agreement was substantial for CT (χ= 0.72, 95 % confidence interval, 0.6-0.84) and DWI (χ= 0.82, 95 % confidence interval, 0.46-1). Taken together, detectability and detection rate of acute (< 6 h) hemisphere infarcts are significantly higher with DWI than with CT. (orig.)

  9. Liver metastases: Sulphur hexafluoride-enhanced ultrasonography for lesion detection: a systematic review

    NARCIS (Netherlands)

    Cabassa, Paolo; Bipat, Shandra; Longaretti, Laura; Morone, Mario; Maroldi, Roberto

    2010-01-01

    This is a systematic review to evaluate the accuracy of contrast-enhanced ultrasonography (CEUS) performed with "SonoVue" (sulphur hexafluoride) in the detection of hepatic metastases. The MEDLINE, EMBASE and COCHRANE Databases were searched, regardless of language, for relevant articles published

  10. HPV detection rate in saliva may depend on the immune system efficiency.

    Science.gov (United States)

    Adamopoulou, Maria; Vairaktaris, Eleftherios; Panis, Vassilis; Nkenke, Emeka; Neukam, Friedreich W; Yapijakis, Christos

    2008-01-01

    Human papilloma virus (HPV) has been established as a major etiological factor of anogenital cancer. In addition, HPV has also been implicated in oral carcinogenesis but its detection rates appear to be highly variable, depending on the patient population tested, the molecular methodology used, as well as the type of oral specimen investigated. For example, saliva is an oral fluid that may play a role in HPV transmission, although the detection rates of the virus are lower than tissue. Recent evidence has indicated that HPV-related pathology is increased in the oral cavity of human immunodeficiency virus (HIV)-positive individuals. In order to investigate whether the presence of different HPV types in saliva depends on immune system efficiency, oral fluid samples of patients with oral cancer and without any known immune deficiency were compared with those of HIV-positive individuals. Saliva samples were collected from 68 patients with oral squamous cell carcinoma and 34 HIV seropositive individuals. HPV DNA sequences were detected by L1 concensus polymerase chain reaction (PCR), followed by restriction fragment length polymorphism (RFLP) analysis and DNA sequencing for HPV typing. HPV DNA was detected in 7/68 (10.3%) of the oral cancer patients and in 12/34 (35.3%) of the HIV-positive individuals, a highly significant difference (p = 0.006; odds ratio 4.753; 95% confidence interval 1.698-13.271). Among HPV-positive samples, the prevalence of HPV types associated with high oncogenic risk was similar in oral cancer and HIV-positive cases (71.4% and 66.7%, respectively). In both groups, the most common HPV type was high-risk 16 (50% and 42.8%, respectively). Although a similar pattern of HPV high-risk types was detected in oral cancer and HIV-positive cases, the quantitative detection of HPV in saliva significantly depended on immune system efficiency. Furthermore, the significantly increased detection rates of HPV in saliva of HIV-positive individuals may be

  11. Detection of Treponema pallidum subsp. pallidum from Skin Lesions, Serum, and Cerebrospinal Fluid in an Infant with Congenital Syphilis after Clindamycin Treatment of the Mother during Pregnancy▿

    Science.gov (United States)

    Woznicová, Vladana; Šmajs, David; Wechsler, Dan; Matějková, Petra; Flasarová, Magdalena

    2007-01-01

    We report here a case of congenital syphilis in a newborn after clindamycin treatment in pregnancy. Using PCR detection of tmpC (TP0319) and DNA sequencing of the genes TP0136 and TP0548, DNA sequences identical to Treponema pallidum subsp. pallidum strain SS14 were detected in the infant's skin lesions, serum, and cerebrospinal fluid. PMID:17151205

  12. A Comparative Study of Data Mining Algorithms for High Detection Rate in Intrusion Detection System

    Directory of Open Access Journals (Sweden)

    Nabeela Ashraf

    2018-01-01

    Full Text Available Due to the fast growth and tradition of the internet over the last decades, the network security problems are increasing vigorously. Humans can not handle the speed of processes and the huge amount of data required to handle network anomalies. Therefore, it needs substantial automation in both speed and accuracy. Intrusion Detection System is one of the approaches to recognize illegal access and rare attacks to secure networks. In this proposed paper, Naive Bayes, J48 and Random Forest classifiers are compared to compute the detection rate and accuracy of IDS. For experiments, the KDD_NSL dataset is used.

  13. Retrospective analysis of technical success rate and procedure-related complications of 867 percutaneous CT-guided needle biopsies of lung lesions.

    Science.gov (United States)

    Mills, M; Choi, J; El-Haddad, G; Sweeney, J; Biebel, B; Robinson, L; Antonia, S; Kumar, A; Kis, B

    2017-12-01

    To investigate the technical success rate and procedure-related complications of computed tomography (CT)-guided needle biopsy of lung lesions and to identify the factors that are correlated with the occurrence of procedure-related complications. This was a single- institution retrospective study of 867 consecutive CT-guided needle biopsies of lung lesions performed on 772 patients in a tertiary cancer centre. The technical success rate and complications were correlated with patient, lung lesion, and procedure-related variables. The technical success rate was 87.2% and the mortality rate was 0.12%. Of the 867 total biopsies 25.7% were associated with pneumothorax, and 6.5% required chest tube drainage. The haemothorax rate was 1.8%. There was positive correlation between the development of pneumothorax and smaller lesion diameter (ptechnical success and a low rate of major complications. The present study has revealed several variables that can be used to identify high-risk procedures. A post-procedural chest X-ray within hours after the procedure is highly recommended to identify high-risk patients who require chest tube placement. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  14. Detection of pathogenic bacteria in skin lesions of patients with chiclero's ulcer: reluctant response to antimonial treatment

    Directory of Open Access Journals (Sweden)

    Isaac-Márquez Angélica Patricia

    2003-01-01

    Full Text Available We investigated the bacterial flora present in skin lesions of patients with chiclero's ulcer from the Yucatan peninsula of Mexico using conventional culture methods (11 patients, and an immunocolorimetric detection of pathogenic Streptococcus pyogenes (15 patients. Prevalence of bacteria isolated by culture methods was 90.9% (10/11. We cultured, from chiclero's ulcers (60%, pathogenic bacterial such as Staphylococcus aureus (20%, S. pyogenes (1.6%, Pseudomonas aeruginosa (1.6%, Morganella morganii (1.6%, and opportunist pathogenic bacteria such as Klebsiella spp. (20.0%, Enterobacter spp. (20%, and Enterococcus spp. (20%. We also cultured coagulase-negative staphylococci in 40% (4/10 of the remaining patients. Micrococcus spp. and coagulase-negative staphylococci constituted the bacterial genuses more frequently isolated in the normal skin of patients with chiclero's ulcer and healthy individuals used as controls. We also undertook another study to find out the presence of S. pyogenes by an immunocolorimetric assay. This study indicated that 60% (9/15 of the ulcerated lesions, but not normal controls, were contaminated with S. pyogenes. Importantly, individuals with purulent secretion and holding concomitant infections with S. pyogenes, S. aureus, P. aeruginosa, M. morganii, and E. durans took longer to heal Leishmania (L. mexicana infections treated with antimonial drugs. Our results suggest the need to eliminate bacterial purulent infections, by antibiotic treatment, before starting antimonial administration to patients with chiclero's ulcer.

  15. Functional MR imaging of the Eustachian tube in patients with clinically proven dysfunction: correlation with lesions detected on MR images

    Energy Technology Data Exchange (ETDEWEB)

    Luekens, Anna; Guenther, Rolf W. [University Hospital, University of Technology (RWTH) Aachen, Department of Diagnostic Radiology, Aachen (Germany); DiMartino, Ercole [Ev. Diakonie-Krankenhaus, Department of Otolaryngology and Head- and Neck-Surgery, Bremen (Germany); Krombach, Gabriele A. [University Hospital, University of Technology (RWTH) Aachen, Department of Diagnostic Radiology, Aachen (Germany); University Hospital Giessen, University Giessen, Department of Diagnostic and Interventional Radiology, Giessen (Germany)

    2012-03-15

    To visualise the function of the Eustachian tube by MRI and assess the effect of surrounding lesions. Using 1.5 T MRI, 32 Eustachian tubes of 16 patients with clinically proven dysfunction (clinical symptoms, such as autophonia and fullness and non-opening at tympanometry) were investigated. For depiction of the anatomy and associated abnormalities, coronal and axial T2-weighted turbo spin echo sequences and a T1-weighted-2D-gradient echo sequences were acquired. Eustachian tube opening was analysed with real time turbo-gradient echo sequences during a Valsalva manoeuvre. Dysfunction, that is, failure of opening of the Eustachian tube as shown by MRI, correlated in all patients with tympanometry. Lesions detected included nasopharyngeal carcinoma in 4 patients. Mucosal swelling in the paranasal sinus was present in 9 patients. One patient had postoperative defects. In two patients both pharyngotympanic tubes did not open although no structural abnormalities could be depicted. The opening of the Eustachian tubes during the Valsalva manoeuvre is assessable on MRI. Failure of opening may be due to swelling of the mucosa and may be also associated with tumours. MRI assessment may be helpful in patients with chronic otitis media, where the information about tubal function is important in preoperative planning. (orig.)

  16. Human papilloma virus 18 detection in oral squamous cell carcinoma and potentially malignant lesions using saliva samples.

    Science.gov (United States)

    Goot-Heah, Khor; Kwai-Lin, Thong; Froemming, Gabriele Ruth Anisah; Abraham, Mannil Thomas; Nik Mohd Rosdy, Nik Mohd Mazuan; Zain, Rosnah Binti

    2012-01-01

    Oral cancer has become one of the most prevalent cancers worldwide and human Papillomavirus is one of the risk factors for developing oral cancer. For this study HPV18 was chosen as it is one of the high risk HPV types and may lead to carcinogenesis. However, prevalence of HPV18 infection in Oral Squamous Cell Carcinoma in Malaysia remains unclear. This study aimed to investigate the viral load of HPV18 DNA in OSCC and potentially malignant lesions using saliva samples. Genomic DNAs of thirty saliva samples of normal subjects and thirty saliva samples compromised of 16 samples from potentially malignant lesions and 14 of OSCC patients were amplified for HPV18 DNA using a nested polymerase chain reaction analysis. All PCR products were then analyzed using the Bioanalyzer to confirm presence of HPV18 DNA. From thirty patients examined, only one of 30 (3.3%) cases was found to be positive for HPV18 in this study. The finding of this study revealed that there is a low viral detection of HPV18 in Malaysian OSCC by using saliva samples, suggesting that prevalence of HPV18 may not be important in this group of Malaysian OSCC.

  17. Correlation of needle core biopsy with excision histology in screen-detected B3 lesions: the Merrion Breast Screening Unit experience.

    LENUS (Irish Health Repository)

    Hayes, B D

    2012-02-01

    AIMS: Needle core biopsy (NCB) is a widely-used technique for non-operative evaluation of screen-detected breast lesions. Although most NCBs are B2 (benign) or B5 (malignant), some fall into the B3 category of "uncertain malignant potential". This study aims to categorise the lesions prompting a B3 NCB in the Merrion Breast Screening Unit, and establish the incidence of malignancy on subsequent excision biopsy. METHODS: Patients attending the Merrion Breast Screening Unit in Dublin between 2000 and 2008 who had a B3 NCB were identified. The NCB pathology reports were reviewed and the diagnosis correlated with excision histology; the latter was classified as benign, atypical or malignant. Lesion-specific positive predictive values (PPVs) for malignancy were derived. RESULTS: 141 patients with a B3 NCB were identified. The most frequent lesions on NCB were radial scar (RS; n = 57), atypical intraductal epithelial proliferation (AIDEP; n = 25) and papillary lesion (n = 24). The final diagnosis was malignant in 22 patients (16%), atypical in 40 (28%) and benign in 79 (56%). Two of the patients with a malignant diagnosis had invasive carcinoma. The lesion-specific PPVs were: lobular neoplasia 50%, AIDEP 32%, columnar cell lesion with atypia 12.5%, RS 12.3%, papillary lesion 8.3%, suspected phyllodes tumour 7.7%, and spindle cell lesion 0%. Atypia on RS NCB predicted an atypical or malignant excision diagnosis, but atypia on papillary lesion NCB did not. CONCLUSIONS: One-sixth of B3 NCBs in this series proved to be malignant on excision. The PPV for malignancy varied according to lesion type.

  18. Respiratory gated PET/CT in a European multicentre retrospective study: added diagnostic value in detection and characterization of lung lesions

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, Luca; Elisei, Federica [San Gerardo Hospital, Nuclear Medicine, Monza (Italy); De Ponti, Elena [San Gerardo Hospital, Medical Physics, Monza (Italy); Bettinardi, Valentino; Picchio, Maria [San Raffaele Scientific Institute, Nuclear Medicine, Milan (Italy); National Research Council, Institute for Bioimaging and Molecular Physiology, Milan (Italy); Landoni, Claudio [San Raffaele Scientific Institute, Nuclear Medicine, Milan (Italy); University of Milano-Bicocca, Milan (Italy); Gilardi, Maria Carla [San Raffaele Scientific Institute, Nuclear Medicine, Milan (Italy); National Research Council, Institute for Bioimaging and Molecular Physiology, Milan (Italy); University of Milano-Bicocca, Tecnomed Foundation, Milan (Italy); Versari, Annibale [Scientific Institute Santa Maria Nuova Hospital, Nuclear Medicine, Reggio Emilia (Italy); Fioroni, Federica [Scientific Institute Santa Maria Nuova Hospital, Medical Physics, Reggio Emilia (Italy); Dziuk, Miroslaw [Masovian PET-CT Centre, Department of Nuclear Medicine, Military Institute of Medicine, Warsaw (Poland); Koza, Magdalena [Masovian PET-CT Centre, Euromedic Diagnostic, Warsaw (Poland); Ahond-Vionnet, Renee; Collin, Bertrand [Hopital Pierre Beregovoy, Service de Medecine Nucleaire, Nevers (France); Messa, Cristina [San Gerardo Hospital, Nuclear Medicine, Monza (Italy); National Research Council, Institute for Bioimaging and Molecular Physiology, Milan (Italy); University of Milano-Bicocca, Tecnomed Foundation, Milan (Italy)

    2012-09-15

    The aim of our work is to evaluate the added diagnostic value of respiratory gated (4-D) positron emission tomography/computed tomography (PET/CT) in lung lesion detection/characterization in a large patient population of a multicentre retrospective study. The data of 155 patients (89 men, 66 women, mean age 63.9 {+-} 11.1 years) from 5 European centres and submitted to standard (3-D) and 4-D PET/CT were retrospectively analysed. Overall, 206 lung lesions were considered for the analysis (mean {+-} SD lesions dimension 14.7 {+-} 11.8 mm). Maximum standardized uptake values (SUV{sub max}) and lesion detectability were assessed for both 3-D and 4-D PET/CT studies; 3-D and 4-D PET/CT findings were compared to clinical follow-up as standard reference. Mean {+-} SD 3-D and 4-D SUV{sub max} values were 5.2 {+-} 5.1 and 6.8 {+-} 6.1 (p < 0.0001), respectively, with an average percentage increase of 30.8 %. In 3-D PET/CT, 86 of 206 (41.7 %) lesions were considered positive, 70 of 206 (34 %) negative and 50 of 206 (24.3 %) equivocal, while in 4-D PET/CT 117 of 206 (56.8 %) lesions were defined as positive, 80 of 206 (38.8 %) negative and 9 of 206 (4.4 %) equivocal. In 34 of 50 (68 %) 3-D equivocal lesions follow-up data were available and the presence of malignancy was confirmed in 21 of 34 (61.8 %) lesions, while in 13 of 34 (38.2 %) was excluded. In 31 of these 34 controlled lesions, 20 of 34 (58.8 %) and 11 of 34 (32.4 %) were correctly classified by 4-D PET/CT as positive and negative, respectively; 3 of 34 (8.8 %) remained equivocal. With equivocal lesions classified as positive, the overall accuracy of 3-D and 4-D was 85.7 and 92.8 %, respectively, while the same figures were 80.5 and 94.2 % when equivocal lesions were classified as negative. The respiratory gated PET/CT technique is a valuable clinical tool in diagnosing lung lesions, improving quantification and confidence in reporting, reducing 3-D undetermined findings and increasing the overall accuracy in lung

  19. Added diagnostic value of respiratory-gated 4D 18F-FDG PET/CT in the detection of liver lesions. A multicenter study

    Energy Technology Data Exchange (ETDEWEB)

    Crivellaro, Cinzia; Landoni, Claudio; Guerra, Luca [San Gerardo Hospital, Nuclear Medicine, Monza (Italy); University of Milan-Bicocca, Milan (Italy); De Ponti, Elena; Morzenti, Sabrina [San Gerardo Hospital, Medical Physics, Monza (Italy); Elisei, Federica [San Gerardo Hospital, Nuclear Medicine, Monza (Italy); Picchio, Maria; Bettinardi, Valentino [IRCCS San Raffaele Scientific Institute, Nuclear Medicine, Milan (Italy); Versari, Annibale [Santa Maria Nuova Hospital IRCCS, Nuclear Medicine, Reggio Emilia (Italy); Fioroni, Federica [Santa Maria Nuova Hospital IRCCS, Medical Physics, Reggio Emilia (Italy); Dziuk, Miroslaw; Tkaczewski, Konrad [Military Institute of Medicine, Warsaw (Poland); Ahond-Vionnet, Renee; Nodari, Guillaume [Hopital Pierre Beregovoy, Service de Medecine Nucleaire, Nevers (France); Todde, Sergio [University of Milan-Bicocca, Tecnomed Foundation, Monza (Italy)

    2018-01-15

    The aim of the present study was to evaluate the added diagnostic value of respiratory-gated 4D18F-FDG PET/CT in liver lesion detection and characterization in a European multicenter retrospective study. Fifty-six oncological patients (29 males and 27 females, mean age, 61.2 ± 11.2 years) from five European centers, submitted to standard 3D-PET/CT and liver 4D-PET/CT were retrospectively evaluated. Based on visual analysis, liver PET/CT findings were scored as positive, negative, or equivocal both in 3D and 4D PET/CT. The impact of 4D-PET/CT on the confidence in classifying liver lesions was assessed. PET/CT findings were compared to histology and clinical follow-up as standard reference and diagnostic accuracy was calculated for both techniques. At semi-quantitative analysis, SUVmax was calculated for each detected lesion in 3D and 4D-PET/CT. Overall, 72 liver lesions were considered for the analysis. Based on visual analysis in 3D-PET/CT, 32/72 (44.4%) lesions were considered positive, 21/72 (29.2%) negative, and 19/72 (26.4%) equivocal, while in 4D-PET/CT 48/72 (66.7%) lesions were defined positive, 23/72 (31.9%) negative, and 1/72 (1.4%) equivocal. 4D-PET/CT findings increased the confidence in lesion definition in 37/72 lesions (51.4%). Considering 3D equivocal lesions as positive, sensitivity, specificity, and accuracy were 88.9, 70.0, and 83.1%, respectively, while the same figures were 67.7, 90.0, and 73.8% if 3D equivocal findings were included as negative. 4D-PET/CT sensitivity, specificity, and accuracy were 97.8, 90.0, and 95.4%, respectively, considering equivocal lesions as positive and 95.6, 90.0, and 93.8% considering equivocal lesions as negative. The SUVmax of the liver lesions in 4D-PET (mean ± SD, 6.9 ± 3.2) was significantly higher (p < 0.001) than SUVmax in 3D-PET (mean ± SD, 5.2 ± 2.3). Respiratory-gated PET/CT technique is a valuable clinical tool in diagnosing liver lesions, reducing 3D undetermined findings, improving diagnostic

  20. The value of digital tomosynthesis of the chest as a problem-solving tool for suspected pulmonary nodules and hilar lesions detected on chest radiography

    Energy Technology Data Exchange (ETDEWEB)

    Galea, Angela, E-mail: galeaangie@gmail.com [Peninsula Radiology Academy, William Prance Road, Plymouth PL65WR (United Kingdom); Dubbins, Paul, E-mail: Paul.dubbins@nhs.net [Plymouth Hospital NHS Trust, Plymouth PL68DH (United Kingdom); Riordan, Richard, E-mail: richardriordan@nhs.net [Plymouth Hospital NHS Trust, Plymouth PL68DH (United Kingdom); Adlan, Tarig, E-mail: tarig.adlan@nhs.net [Plymouth Hospital NHS Trust, Plymouth PL68DH (United Kingdom); Roobottom, Carl, E-mail: carl.roobotoom@nhs.net [Plymouth Hospital NHS Trust, Plymouth PL68DH (United Kingdom); Gay, David, E-mail: davegay@nhs.net [Plymouth Hospital NHS Trust, Plymouth PL68DH (United Kingdom)

    2015-05-15

    Graphical abstract: When compared to CXR, DTS has: • Superior resolution • Better assessment of location in the AP dimension (better at locating a pleural or intrapulmonary lesion) • Better characterisation (better at distinguishing between calcified plaque and soft tissue) • Removes composite artefact caused by overlying anatomical structures (such as the ribs or pulmonary vessels) DTS has improved sensitivity, specificity and accuracy when compared to CXR. - Highlights: • DTS is a type of limited angle tomography. Sixty coronal reconstructed images of the chest are produced that combine the superior resolution of radiography with the tomographic benefits of computed tomography. • The sensitivity for detecting a suspected lung lesions is 0.65 with CXR and 0.91 for DTS. • The high specificity of DTS (1) and the high negative predictive value (0.94) are similar to CT and suggest that if the DTS is normal patients do not need further assessment with CT with significant potential dose savings. • 50% of suspected lesions were resolved with CXR, this improved to 96% with DTS. - Abstract: Objectives: To assess the capability of digital tomosynthesis (DTS) of the chest compared to a postero-anterior (PA) and lateral chest radiograph (CXR) in the diagnosis of suspected but unconfirmed pulmonary nodules and hilar lesions detected on a CXR. Computed tomography (CT) was used as the reference standard. Materials and method: 78 patients with suspected non-calcified pulmonary nodules or hilar lesions on their CXR were included in the study. Two radiologists, blinded to the history and CT, prospectively analysed the CXR (PA and lateral) and the DTS images using a picture archiving and communication workstation and were asked to designate one of two outcomes: true intrapulmonary lesion or false intrapulmonary lesion. A CT of the chest performed within 4 weeks of the CXR was used as the reference standard. Inter-observer agreement and time to report the modalities

  1. The value of digital tomosynthesis of the chest as a problem-solving tool for suspected pulmonary nodules and hilar lesions detected on chest radiography

    International Nuclear Information System (INIS)

    Galea, Angela; Dubbins, Paul; Riordan, Richard; Adlan, Tarig; Roobottom, Carl; Gay, David

    2015-01-01

    Graphical abstract: When compared to CXR, DTS has: • Superior resolution • Better assessment of location in the AP dimension (better at locating a pleural or intrapulmonary lesion) • Better characterisation (better at distinguishing between calcified plaque and soft tissue) • Removes composite artefact caused by overlying anatomical structures (such as the ribs or pulmonary vessels) DTS has improved sensitivity, specificity and accuracy when compared to CXR. - Highlights: • DTS is a type of limited angle tomography. Sixty coronal reconstructed images of the chest are produced that combine the superior resolution of radiography with the tomographic benefits of computed tomography. • The sensitivity for detecting a suspected lung lesions is 0.65 with CXR and 0.91 for DTS. • The high specificity of DTS (1) and the high negative predictive value (0.94) are similar to CT and suggest that if the DTS is normal patients do not need further assessment with CT with significant potential dose savings. • 50% of suspected lesions were resolved with CXR, this improved to 96% with DTS. - Abstract: Objectives: To assess the capability of digital tomosynthesis (DTS) of the chest compared to a postero-anterior (PA) and lateral chest radiograph (CXR) in the diagnosis of suspected but unconfirmed pulmonary nodules and hilar lesions detected on a CXR. Computed tomography (CT) was used as the reference standard. Materials and method: 78 patients with suspected non-calcified pulmonary nodules or hilar lesions on their CXR were included in the study. Two radiologists, blinded to the history and CT, prospectively analysed the CXR (PA and lateral) and the DTS images using a picture archiving and communication workstation and were asked to designate one of two outcomes: true intrapulmonary lesion or false intrapulmonary lesion. A CT of the chest performed within 4 weeks of the CXR was used as the reference standard. Inter-observer agreement and time to report the modalities

  2. High detection rate of dog circovirus in diarrheal dogs.

    Science.gov (United States)

    Hsu, Han-Siang; Lin, Ting-Han; Wu, Hung-Yi; Lin, Lee-Shuan; Chung, Cheng-Shu; Chiou, Ming-Tang; Lin, Chao-Nan

    2016-06-17

    Diarrhea is one of the most common clinical symptoms reported in companion animal clinics. Dog circovirus (DogCV) is a new mammalian circovirus that is considered to be a cause of alimentary syndromes such as diarrhea, vomiting and hemorrhagic enteritis. DogCV has previously only been identified in the United States, Italy, Germany (GeneBank accession number: KF887949) and China (GeneBank accession number: KT946839). Therefore, the aims of this study were to determine the prevalence of DogCV in Taiwan and to explore the correlation between diarrhea and DogCV infection. Clinical specimens were collected between 2012 and 2014 from 207 dogs suffering from diarrhea and 160 healthy dogs. In this study, we developed a sensitive and specific SYBR Green-based real-time PCR assays to detected DogCV in naturally infected animals. Of the analyzed fecal samples from diarrheal dogs and health dogs, 58 (28.0 %) and 19 (11.9 %), respectively, were DogCV positive. The difference in DogCV prevalence was highly significant (P = 0.0002755) in diarrheal dogs. This is the first study to reveal that DogCV is currently circulating in domestic dogs in Taiwan and to demonstrate its high detection rate in dogs with diarrhea.

  3. The role of MSCT angiography in early detection of lower limb arterial lesions in patients with antiphospholipid syndrome.

    Science.gov (United States)

    Saponjski, Jovica; Stojanovich, Ljudmila; Petrovic, Jelena; Saponjski, Dusan

    2017-04-01

    Antiphospholipid syndrome (APS) is an autoimmune disease which is characterized by arterial and venous thromboses, fetal loss, and the presence of antiphospholipid antibodies in the serum. It is characterized by accelerated atherosclerosis. Increased tendency towards thrombosis leads to the occurrence of various vascular events. The objective of our study was to determine if there are subclinical changes on lower limb arteries in APS patients and what the best diagnostic choice for their establishment is. In this study, we analyzed 50 patients with primary antiphospholipid syndrome (PAPS) and 50 patients, who have secondary antiphospholipid syndrome (SAPS). The results were compared to 50 controls. The groups were comparable with respect to age, gender, and traditional risk factors except for the lipid status, since controls had significantly higher levels of cholesterol and triglycerides. Study was conducted on 64-multi-slice computed tomography (64-MSCT), where we analyzed quantitative and morphological characteristics of blood vessel-detected lesions. Patients from the control group had statistically very significant elevated cholesterol and triglyceride levels in regard to the patients with SAPS and PAPS (p < 0.001 and p < 0.05). Analyzing percentage of diameter stenosis, we have established that lesions from group with 0-30% diameter stenosis (DS) in patients with PAPS (n = 47) and SAPS (n = 39) are more common than that in control group (n = 3, p < 0.001). The incidence of lesions higher than 70% DS in control group (n = 74) was statistically significant than that in patients with SAPS (n = 74, p < 0.05), while very statistically significant than that in patients with PAPS (n = 48, p < 0.001). Analyzing the qualitative characteristics of plaques, we have established significant higher frequency of soft tissue (n = 32) and mixed lesions (n = 36) in patients with PAPS than the calcified one (n = 7, p < 0.001). Our study showed that

  4. Scintigraphic detection of ischemic and other myocardial lesions using 201Tl

    International Nuclear Information System (INIS)

    Duska, F.; Novak, J.; Vizda, J.; Kubicek, J.; Kafka, P.

    1981-01-01

    Current knowledge of the myocardium scintiscanning using 201 Tl is briefly outlined. The principle is shown of 201 Tl cumulation in a healthy myocardium and the use of the radionuclide is justified. Heart scintiscanning after exercise or after administration of drugs increasing the blood flow through the coronaries allows detecting latent ischaemic heart disease. 201 Tl scintigraphy can also be used for diagnosing the myocardial infarction, angina pectoris and other heart diseases. (J.P.)

  5. An oxygen dependent X-ray lesion in Escherichia coli strain B/r detected by penicillin

    International Nuclear Information System (INIS)

    Gillies, N.E.; Obioha, F.I.; Ratnajothi, N.H.

    1979-01-01

    Enhancement of lethal damage to E. coli B/r by penicillin was observed after X-irradiation under aerobic conditions, but not after exposure to X-rays under anoxia or after U.V. (260 nm) irradiation. No enhancement of damage occurred when incubation with penicillin was delayed for 2 hours after aerobic X-irradiation. This enhancing effect was only detected in this strain and not in the filamentous strain E. coli B. It was concluded that an X-ray induced lesion, sensitive to the presence of oxygen at the time of irradiation and probably located in the cell envelope, initiates filamentation in E. coli B/r, which results in lethal damage in this strain. (author)

  6. Detection of precancerous lesions in the oral cavity using oblique polarized reflectance spectroscopy: a clinical feasibility study

    Science.gov (United States)

    Bailey, Maria J.; Verma, Nishant; Fradkin, Leonid; Lam, Sylvia; MacAulay, Calum; Poh, Catherine; Markey, Mia K.; Sokolov, Konstantin

    2017-06-01

    We developed a multifiber optical probe for oblique polarized reflectance spectroscopy (OPRS) in vivo and evaluated its performance in detection of dysplasia in the oral cavity. The probe design allows the implementation of a number of methods to enable depth resolved spectroscopic measurements including polarization gating, source-detector separation, and differential spectroscopy; this combination was evaluated in carrying out binary classification tasks between four major diagnostic categories: normal, benign, mild dysplasia (MD), and severe dysplasia (SD). Multifiber OPRS showed excellent performance in the discrimination of normal from benign, MD, SD, and MD plus SD yielding sensitivity/specificity values of 100%/93%, 96%/95%, 100%/98%, and 100%/100%, respectively. The classification of benign versus dysplastic lesions was more challenging with sensitivity and specificity values of 80%/93%, 71%/93%, and 74%/80% in discriminating benign from SD, MD, and SD plus MD categories, respectively; this challenge is most likely associated with a strong and highly variable scattering from a keratin layer that was found in these sites. Classification based on multiple fibers was significantly better than that based on any single detection pair for tasks dealing with benign versus dysplastic sites. This result indicates that the multifiber probe can perform better in the detection of dysplasia in keratinized tissues.

  7. Lesion-based detection of early chemosensitivity using serial static FDG PET/CT in metastatic colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Buvat, Irene; Necib, Hatem [IMNC UMR 8165 CNRS - Paris 7 and Paris 11 Universities, Orsay cedex (France); Garcia, Camilo; Wagner, Antoine; Vanderlinden, Bruno; Flamen, Patrick [Universite Libre de Bruxelles, Nuclear Medicine Department, Institut Jules Bordet, Brussels (Belgium); Emonts, Patrick [Universite Libre de Bruxelles, Radiology Department, Institut Jules Bordet, Brussels (Belgium); Hendlisz, Alain [Universite Libre de Bruxelles, Digestive Oncology, Institut Jules Bordet, Brussels (Belgium)

    2012-10-15

    Medical oncology needs early identification of patients that are not responding to systemic therapy. {sup 18}F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) performed before and early during treatment has been proposed for this purpose. However, the best way to assess the change in FDG uptake between two scans has not been identified. We studied cutoff thresholds to identify responding tumours as a function of the method used to measure tumour uptake. The study included 28 metastatic colorectal cancer (mCRC) patients who underwent 2 FDG PET/CT scans (baseline and at day 14 of the first course of polychemotherapy). For 78 tumour lesions, 4 standardized uptake value (SUV) indices were measured: maximum SUV (SUV{sub max}) and mean SUV in a region obtained using an isocontour (SUV{sub 40} {sub %}), with each of these SUV normalized either by the patient body weight (BW) or body surface area (BSA). The per cent change and absolute change in tumour uptake between the baseline and the early PET scans were measured based on these four indices. These changes were correlated to the RECIST 1.0-based response using contrast-enhanced CT at baseline and at 6-8 weeks on treatment. The 78 tumours were classified as non-responding (NRL, n = 58) and responding lesions (RL, n = 20). Receiver-operating characteristic (ROC) curves characterizing the performance in NRL/RL classification using early FDG PET uptake had areas under the curve between 0.75 and 0.84, without significant difference between the indices. The cutoff threshold in FDG uptake per cent change to get a 95 % sensitivity of RL detection depended on the way uptake was measured: -14 % (specificity of 53 %) and -22 % (specificity of 64 %) for SUV{sub max} and SUV{sub 40} {sub %}, respectively. Thresholds expressed as absolute SUV decrease instead of per cent change were less sensitive to the SUV definition: an SUV decline by 1.2 yielded a sensitivity of RL detection of 95 % for SUV{sub max} and SUV{sub 40

  8. The Use of Fluorescence Technology versus Visual and Tactile Examination in the Detection of Oral Lesions: A Pilot Study.

    Science.gov (United States)

    Ayoub, Hadeel M; Newcomb, Tara L; McCombs, Gayle B; Bonnie, Marshall

    2015-02-01

    This study compared the effectiveness of the VELscope® Vx versus visual and tactile intraoral examination in detecting oral lesions in an adult, high risk population. The pilot study compared the intra oral findings between 2 examination types. The sample was comprised of 30 participants who were addicted to either cigarettes or a dual addiction (cigarettes plus hookah). High risk population was defined as males who were current cigarette smokers or had a dual addiction. Two trained and experienced licensed dental hygienists conducted all examinations. Throughout the study, all visual and tactile intraoral examinations were conducted first by one dental hygienist first, followed by the VELscope® Vx fluorescence examinations by the second dental hygienist. All subjects received an inspection of the lips, labial and buccal mucosa, floor of the mouth, dorsal, ventral and lateral sides of the tongue, hard and soft palate, and visual inspection of the oropharynx and uvula. Both evaluations took place in 1 visit in the Dental Hygiene Research Center at Old Dominion University and external sites. All participants received oral cancer screening information, recommendations, referrals for tobacco cessation programs and brochures on the 2 types of examinations conducted. Participants were considered high risk based on demographics (current smokers and mostly males). Neither visual and tactile intraoral examination nor the VELscope® Vx examination showed positive lesions. No lesions were detected; therefore, no referrals were made. Data indicated the duration of tobacco use was significantly higher in cigarette smokers (14.1 years) than dual addiction smokers (5 years) (p>0.005). The average numbers of cigarettes smoked per day were 13.5 compared to 14.2 cigarettes for dual addiction smokers. Results from this study suggest the visual and tactile intraoral examination produced comparative results to the VELscope® Vx examination. Findings from this study support that the

  9. 111In-Octreotide and 99mTc-MDP scintigraphy in the detection of bone lesions in Langerhans cell histiocytosis

    International Nuclear Information System (INIS)

    Hervas, I.; Bello, P.; Gonzalez-Cabezas, P.; Flores, D.; Perez-Velasco, R.; Torres, I.; Castel, V.; Mateo, A.; Canete, A.

    2002-01-01

    Aim: Langerhans cell histiocytosis (LCH) is a granulomatous disease which can involve multiples sites of the body. Diagnostic imaging is of utmost importance in the management of these patients. Since now radiographic skeletal survey and bone scintigraphy (BS) have been used to assess bone involvement (both with low specificity). Magnetic resonance and CT have been used to assess visceral involvement but with the limitation that can not give information about the functional status. Recently two groups of investigators (Lastoria et al. and Calming et al.) have proposed somatostatin receptor scintigraphy (SSRS) to detect active lesions and for monitoring the response to treatment, due to the somatostatin analogue octreotide binds to the cell membrane of activated lymphocytes expressing somatostatine receptors. The aim of this study is to assess bone and somatostatine receptor scintigraphy in the detection of bone involvement in LCH in children. Visceral involvement has not been assessed due to none of the patients presented it at the moment of the SRS. Methods: 17 scintigraphies (11 SSRS and 6 BS) were performed in seven patients (3 girls and 4 boys) aged at diagnosis: 18 month- 12 years (mean age 6,2 years). The findings obtained in the scintigraphies were compared with clinical evolution and other imaging techniques. Results: All the BS detected the diagnosed lesions, that decreased the uptake after the treatment. In three cases BS detected one unknown bone lesion. Two SSRS could not detect a lesion on right rib in two patients, both at the moment of diagnosis. SSRS was true negative in one patient (clinical and other imaging remission) and true positive in the other four cases. SSRS detected three new unknown bone lesions. SRSS showed decreased uptake after treatment and increased uptake in the relapses. Conclusions: Somatostatin receptor and Bone scintigraphy can be used to detect active LCH bone lesions in children and can help in monitoring the response to

  10. Impact of the use of an endorectal coil for 3 T prostate MRI on image quality and cancer detection rate.

    Science.gov (United States)

    Gawlitza, Josephin; Reiss-Zimmermann, Martin; Thörmer, Gregor; Schaudinn, Alexander; Linder, Nicolas; Garnov, Nikita; Horn, Lars-Christian; Minh, Do Hoang; Ganzer, Roman; Stolzenburg, Jens-Uwe; Kahn, Thomas; Moche, Michael; Busse, Harald

    2017-02-01

    This work aims to assess the impact of an additional endorectal coil on image quality and cancer detection rate within the same patients. At a single academic medical center, this transversal study included 41 men who underwent T2- and diffusion-weighted imaging at 3 T using surface coils only or in combination with an endorectal coil in the same session. Two blinded readers (A and B) randomly evaluated all image data in separate sessions. Image quality with respect to localization and staging was rated on a five-point scale. Lesions were classified according to their prostate imaging reporting and data system (PIRADS) score version 1. Standard of reference was provided by whole-mount step-section analysis. Mean image quality scores averaged over all localization-related items were significantly higher with additional endorectal coil for both readers (p < 0.001), corresponding staging-related items were only higher for reader B (p < 0.001). With an endorectal coil, the rate of correctly detecting cancer per patient was significantly higher for reader B (p < 0.001) but not for reader A (p = 0.219). The numbers of histologically confirmed tumor lesions were rather similar for both settings. The subjectively rated 3-T image quality was improved with an endorectal coil. In terms of diagnostic performance, the use of an additional endorectal coil was not superior.

  11. Performance evaluation of the Aptima HSV-1 and 2 assay for the detection of HSV in cutaneous and mucocutaneous lesion specimens.

    Science.gov (United States)

    Sam, Soya S; Caliendo, Angela M; Ingersoll, Jessica; Abdul-Ali, Deborah; Kraft, Colleen S

    Timely and precise laboratory diagnosis of Herpes simplex viruses (HSV) is required to guide clinical management. The study evaluated limit of detection (LOD) and performance characteristics of the Aptima HSV 1 & 2 assay in comparison to four assays. The multi-center study compared qualitative detection of HSV-1 and 2 by the Aptima HSV-1 and 2 assay (Hologic) to ELVIS culture, Lyra Direct (Quidel), AmpliVue (Quidel) and a laboratory developed test (LDT). LOD was performed using VTM and STM diluted viral concentrations and clinical performance was evaluated using 505 swab specimens. The Aptima LOD studies performed showed a lower detection limit for STM specimens as 1450 copies/mL and 430 copies/mL for HSV1 and HSV-2 respectively; the LOD for VTM specimens was 9370 copies/mL and 8045 copies/mL for HSV-1 and HSV-2 respectively. When the assays were analyzed based on the positive consensus result established the Aptima had 95% of percent positive agreement (PPA) and 100% negative percent agreement (NPA) for the HSV-1. For the HSV-2, the PPA and NPA for Aptima were 96% and 100% respectively. AmpliVue had 1.8% invalid rate, while Lyra had no invalid results but an inhibition rate of 0.8%. Aptima and LDT did not have any invalid or inhibited results. The results indicate that the Aptima HSV-1 & 2 assay is sensitive and the performance characteristics of the Aptima assay is comparable to the assays analyzed for the detection and differentiation of HSV-1 and 2 from cutaneous and mucocutaneous lesions. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Incremento de la detección de lesiones cervicales mediante inspección visual. Puerto Esperanza. 2008 Detection Increase of cervix lesions by means of visual examination in Puerto Esperanza, 2008

    Directory of Open Access Journals (Sweden)

    José G Sanabria Negrín

    2011-09-01

    Full Text Available Las pruebas visuales del cuello uterino mediante ácido acético al 4-5 % (IVA y Lugol (IVSL contribuyen a detectar lesiones. Este constituye el primer reporte de su uso en Cuba. Objetivo: demostrar el incremento de la detección de lesiones cervicales premalignas y malignas mediante el uso de pruebas visuales en la APS. Método: estudio de casos-controles en Puerto Esperanza, Viñales, 2008. Universo: Mujeres de 15-64 años con relaciones sexuales penetrantes. Muestra: Mujeres con pruebas visuales y citología alterada (n1= 18 casos o no (n2= 178 controles. En Patología de Cuello se les practicó colposcopia y biopsia dirigida o por conización con asa diatérmica. Se calcularon frecuencias absolutas y relativas porcentuales y la probabilidad de detectar lesiones por las pruebas aisladas o en conjunto, además de las pruebas de rendimiento diagnóstico. Resultados: IVA e IVSL resultaron positivas en 92.9% y 79.6%, respectivamente. La probabilidad conjunta de tener lesiones fue 0.7395. Con citología alterada el 88.9 % tenía IVA+ y 77,9 % tuvo IVSL+. La colposcopia resultó positiva en el 70.9 % y la probabilidad de tener una lesión mediante pruebas visuales y la colposcopia fue 0.516. De las 136 mujeres biopsiadas resultaron útiles el 99.3%, de las cuales casi el 50 % tuvo lesiones premalignas/malignas. Las pruebas de rendimiento fueron superiores para la IVA y la IVSL que para la citología. No se detectó cáncer invasor, pero sí carcinomas in situ. Conclusión: las pruebas visuales aumentaron la cantidad de diagnósticos en 4 veces y debe generalizarse su uso.Visual examination of cervix using acetic acid up to 4-5% (VIA and Lugol's solution (VILI contribute to detect lesions. This constitutes the first report of their use in Cuba. Objective: to demonstrate the detection increase of pre-malignant and malignant cervical lesions by means of visual examination in Primary Health Care. Method: control-case studies in Puerto Esperanza, Vi

  13. Are oblique views necessary for detecting space occupying lesions in liver scintigraphy

    International Nuclear Information System (INIS)

    Koizumi, Kiyoshi; Seki, Hiroyasu; Taki, Junichi; Yokoyama, Kunihiko; Tada, Akira

    1983-01-01

    In colloid scanning of the liver to determine the presence or absence of SOL(s), it has been suggested that oblique views are desirable. However, it is not popular in Japan to obtain oblique views in routine liver imgaing. The present study was conducted to determine whether such additional views are necessary or not. Liver images of 20 patients with SOL(s) and 84 patients without SOL, all of which were confirmed by ultrasonography, transmission computed tomography and/or clinical course, were evaluated initially using 4 standard views and then adding oblique views by 6 physicians (3 experts and 3 freshmen in nuclear medicine). The numbers of cases showing different interpretation between 4 views and 6 views were 15, 10 and 13 each when interpreted by 3 experts. However, those were 21, 33 and 18 each when interpreted by 3 freshmen. Sensitivity for detecting SOL was improved in 3 physicians by adding oblique views, but was the same in other 3. Specificity was improved in only one physicinan. Overall accuracy was consequently improved in 4 physicians and was deteriorated in 2 physicians. ROC analysis revealed that in the freshman group more accurate interpretation was attained by using 6 views, but in the expert group false-positive cases were increased by using 6 views. Some cases showing usefulness for detecting SOL were presented. In conclusion, oblique views gave more accurate interpretation in inexpertienced observers, and useful information in some cases. (author)

  14. Reduction in training time of a deep learning model in detection of lesions in CT

    Science.gov (United States)

    Makkinejad, Nazanin; Tajbakhsh, Nima; Zarshenas, Amin; Khokhar, Ashfaq; Suzuki, Kenji

    2018-02-01

    Deep learning (DL) emerged as a powerful tool for object detection and classification in medical images. Building a well-performing DL model, however, requires a huge number of images for training, and it takes days to train a DL model even on a cutting edge high-performance computing platform. This study is aimed at developing a method for selecting a "small" number of representative samples from a large collection of training samples to train a DL model for the could be used to detect polyps in CT colonography (CTC), without compromising the classification performance. Our proposed method for representative sample selection (RSS) consists of a K-means clustering algorithm. For the performance evaluation, we applied the proposed method to select samples for the training of a massive training artificial neural network based DL model, to be used for the classification of polyps and non-polyps in CTC. Our results show that the proposed method reduce the training time by a factor of 15, while maintaining the classification performance equivalent to the model trained using the full training set. We compare the performance using area under the receiveroperating- characteristic curve (AUC).

  15. [Low rate of oropharyngeal human papillomavirus infection among women with cervical lesion. Preliminary results from the South-Eastern Hungarian population].

    Science.gov (United States)

    Vanya, Melinda; Jakó, Mária; Terhes, Gabriella; Szakács, László; Kaiser, László; Deák, Judit; Bártfai, György

    2016-01-10

    Although the natural history of cervical and oral human papillomavirus infection has been intensively investigated in the past years, the ability of this virus to infect oral and genital mucosae in the same individual and its potential to co-infect both cervical and oral mucosa are still unclear. The aim of the authors was to assess the presence of oropharyngeal human papillomavirus infection in women with cervical lesions in the South-Eastern Hungarian population. The total of 103 women have been included in the study between March 1, 2013 and January 1, 2015. Brushing was used to collect cells from the oropharyngeal mucosa. Human papillomavirus DNA was detected using polymerase chain reaction, and Amplicor line blot test was used for genotyping. Oropharyngeal human papillomavirus infection was detected in 2 cases (3%). The detected genotypes were 31, 40/61 and 73 in the oropharyngeal region. The results indicate that in women with cervical lesions oropharyngeal human papillomavirus infection rarely occurs.

  16. Real-time MRI navigated US: Role in diagnosis and guided biopsy of incidental breast lesions and axillary lymph nodes detected on breast MRI but not on second look US

    Energy Technology Data Exchange (ETDEWEB)

    Pons, Elena Pastor, E-mail: elenapastorpons@gmail.com; Azcón, Francisco Miras, E-mail: frmiaz00@gmail.com; Casas, María Culiañez, E-mail: mariacc1980@gmail.com; Meca, Salvador Martínez, E-mail: isalvaa@hotmail.com; Espona, José Luis García, E-mail: gespona@hotmail.com

    2014-06-15

    Objectives: To prospectively evaluate the accuracy of real-time ultrasound combined with supine-MRI using volume navigation technique (RtMR-US) in diagnosis and biopsy of incidental breast lesions (ILSM) and axillary lymph nodes (LNSM) suspicious of malignancy on contrast enhanced magnetic resonance imaging (CE-MRI). Materials and methods: Five hundred and seventy-seven women were examined using breast CE-MRI. Those with incidental breast lesions not identified after second-look ultrasound (US) were recruited for RtMR-US. Biopsy was performed in ILSM. Breast lesions were categorized with BI-RADS system and Fisher’ exact test. Axillary lymph nodes morphology was described. To assess efficacy of RtMR-US, diagnostic accuracy, sensitivity, specificity, detection rate and Kappa index of conventional-US and RtMR-US were calculated. Results: Forty-three lesions were detected on CE-MRI before navigation. Eighteen were carcinomas and 25 ILSM. Of these, 21 underwent a RtMR-US. Detection rate on RtMR-US (90.7%) was higher than on conventional-US (43%) (p < 0.001). Agreement between both techniques was low (k = 0.138). Twenty ILSM and 2 LNSM were biopsied. Sixty-five percent were benign (100% of BI-RADS3 and 56% of BI-RADS4-5). Diagnostic performance of RtMR-US identifying malignant nodules for overall lesions and for the subgroup of ILSM was respectively: sensitivity 96.3% and 100%, specificity 18.8% and 30.7%, positive predictive value 66.7% and 43.7%, negative predictive value 75% and 100%. In addition RtMR-US enabled biopsy of 2 metastatic lymph nodes. Conclusions: Real time-US with supine-MRI using a volume navigation technique increases the detection of ILSM. RtMR-US may be used to detect occult breast carcinomas and to assess cancer extension, preventing unnecessary MRI-guided biopsies and sentinel lymph node biopsies. Incidental lesions BI-RADS 3 non-detected on conventional-US are probably benign.

  17. Bayesian analysis of energy and count rate data for detection of low count rate radioactive sources

    Energy Technology Data Exchange (ETDEWEB)

    Klumpp, John [Colorado State University, Department of Environmental and Radiological Health Sciences, Molecular and Radiological Biosciences Building, Colorado State University, Fort Collins, Colorado, 80523 (United States)

    2013-07-01

    We propose a radiation detection system which generates its own discrete sampling distribution based on past measurements of background. The advantage to this approach is that it can take into account variations in background with respect to time, location, energy spectra, detector-specific characteristics (i.e. different efficiencies at different count rates and energies), etc. This would therefore be a 'machine learning' approach, in which the algorithm updates and improves its characterization of background over time. The system would have a 'learning mode,' in which it measures and analyzes background count rates, and a 'detection mode,' in which it compares measurements from an unknown source against its unique background distribution. By characterizing and accounting for variations in the background, general purpose radiation detectors can be improved with little or no increase in cost. The statistical and computational techniques to perform this kind of analysis have already been developed. The necessary signal analysis can be accomplished using existing Bayesian algorithms which account for multiple channels, multiple detectors, and multiple time intervals. Furthermore, Bayesian machine-learning techniques have already been developed which, with trivial modifications, can generate appropriate decision thresholds based on the comparison of new measurements against a nonparametric sampling distribution. (authors)

  18. Detection of up to 65% of Precancerous Lesions of the Human Colon and Rectum by Mutation Analysis of APC, K-Ras, B-Raf and CTNNB1

    International Nuclear Information System (INIS)

    Schneider, Mandy; Scholtka, Bettina; Gottschalk, Uwe; Faiss, Siegbert; Schatz, Daniela; Berghof-Jäger, Kornelia; Steinberg, Pablo

    2010-01-01

    In the present study a recently conceived 4-gene marker panel covering the Wnt and Ras-Raf-MEK-MAPK signaling pathways was used to analyze 20 colorectal serrated lesions and 41 colorectal adenoma samples and to determine the percentage of each of the above-mentioned potentially precancerous lesions carrying at least one of the four above-mentioned genes in a mutated form. CTNNB1 and B-Raf were screened by PCR-single-strand conformation polymorphism analysis, K-Ras by restriction fragment length polymorphism analysis and the APC gene mutation cluster region (codons 1243–1567) by direct DNA sequencing. APC mutations were only detected in 10% of the serrated lesions but in 34% of the adenomas. Twenty percent of the serrated lesions and 14% of the adenomas carried a mutated K-Ras. B-Raf was found to be mutated in 50% of the serrated lesions and in 22% of the adenomas. CTNNB1 was altered in 12% of the adenomas, but not in serrated lesions. By using the above gene marker panel it could be shown that 65% of the serrated lesions and 61% of the adenomas carried at least one of the four genes in a mutated form. Based on its excellent performance in detecting mutations in sporadic preneoplastic (in this study) and neoplastic lesions (in a previous study) of the human colon and rectum, this primer combination might also be suited to efficiently and non-invasively detect genetic alterations in stool DNA of patients with early colorectal cancer

  19. Detection of up to 65% of Precancerous Lesions of the Human Colon and Rectum by Mutation Analysis of APC, K-Ras, B-Raf and CTNNB1

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Mandy; Scholtka, Bettina, E-mail: scholtka@uni-potsdam.de [Chair of Nutritional Toxicology, Institute of Nutritional Science, University of Potsdam, Arthur- Scheunert-Allee 114-116, 14558 Nuthetal (Germany); Gottschalk, Uwe [Maria Heimsuchung Caritas-Klinik Pankow, Breite Straße 46/47, 13187 Berlin (Germany); Faiss, Siegbert [III. Medizinische Abteilung - Gastroenterologie und Hepatologie, Asklepios Klinik Barmbek, Rubenkamp 220, 22291 Hamburg (Germany); Schatz, Daniela; Berghof-Jäger, Kornelia [BIOTECON Diagnostics GmbH, Hermannswerder Haus 17, 14473 Potsdam (Germany); Steinberg, Pablo, E-mail: scholtka@uni-potsdam.de [Chair of Nutritional Toxicology, Institute of Nutritional Science, University of Potsdam, Arthur- Scheunert-Allee 114-116, 14558 Nuthetal (Germany); Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, 30173 Hannover (Germany)

    2010-12-29

    In the present study a recently conceived 4-gene marker panel covering the Wnt and Ras-Raf-MEK-MAPK signaling pathways was used to analyze 20 colorectal serrated lesions and 41 colorectal adenoma samples and to determine the percentage of each of the above-mentioned potentially precancerous lesions carrying at least one of the four above-mentioned genes in a mutated form. CTNNB1 and B-Raf were screened by PCR-single-strand conformation polymorphism analysis, K-Ras by restriction fragment length polymorphism analysis and the APC gene mutation cluster region (codons 1243–1567) by direct DNA sequencing. APC mutations were only detected in 10% of the serrated lesions but in 34% of the adenomas. Twenty percent of the serrated lesions and 14% of the adenomas carried a mutated K-Ras. B-Raf was found to be mutated in 50% of the serrated lesions and in 22% of the adenomas. CTNNB1 was altered in 12% of the adenomas, but not in serrated lesions. By using the above gene marker panel it could be shown that 65% of the serrated lesions and 61% of the adenomas carried at least one of the four genes in a mutated form. Based on its excellent performance in detecting mutations in sporadic preneoplastic (in this study) and neoplastic lesions (in a previous study) of the human colon and rectum, this primer combination might also be suited to efficiently and non-invasively detect genetic alterations in stool DNA of patients with early colorectal cancer.

  20. Cerebral ischemic lesions detected with diffusion-weighted magnetic resonance imaging after carotid artery stenting. Comparison of several anti-embolic protection devices

    International Nuclear Information System (INIS)

    Taha, M.M.; Maeda, Masayuki; Sakaida, Hiroshi

    2009-01-01

    Distal embolism is an important periprocedural technical complication with carotid angioplasty and carotid artery stenting (CAS). We evaluated the safety and efficacy of protection devices used during CAS by detecting new cerebral ischemic lesions using diffusion-weighted magnetic resonance imaging in 95 patients who underwent 98 CAS procedures: 34 using single PercuSurge GuardWire, 31 using double balloon protection, 15 using proximal flow reverse protection devices, 14 using Naviballoon, and 4 using filter anti-embolic devices. Diffusion-weighted imaging was performed preoperatively and postoperatively to evaluate the presence of any new embolic cerebral lesions. Postoperative diffusion-weighted imaging revealed 117 new ischemic lesions. Three patients had new ischemic stroke, two minor and one major, all ipsilateral to the treated carotid artery. The remaining patients had clinically silent ischemia. The incidence of new embolic lesions was lower using the proximal flow reverse protection device than with the double balloon protection (33% vs. 48.4%), but the volume of ipsilateral new ischemic lesions per patient was 136.6 mm 3 vs. 86.9 mm 3 , respectively. Neuroprotection with Naviballoon yielded ipsilateral lesions of large volume (86.6 mm 3 ) and higher number (5.7 lesions per patient) than using the filter anti-embolic device (34.8 mm 3 and 1 lesion per patient). New cerebral ischemic lesions after neuroprotected CAS are usually silent. The lower incidence of distal ischemia using proximal flow reverse and double balloon protection devices is limited by the larger volume and higher number of ischemic lesions. (author)

  1. Cerebral ischemic lesions detected with diffusion-weighted magnetic resonance imaging after carotid artery stenting: Comparison of several anti-embolic protection devices.

    Science.gov (United States)

    Taha, Mahmoud M; Maeda, Masayuki; Sakaida, Hiroshi; Kawaguchi, Kenji; Toma, Naoki; Yamamoto, Akitaka; Hirose, Tomofumi; Miura, Youichi; Fujimoto, Masashi; Matsushima, Satoshi; Taki, Waro

    2009-09-01

    Distal embolism is an important periprocedural technical complication with carotid angioplasty and carotid artery stenting (CAS). We evaluated the safety and efficacy of protection devices used during CAS by detecting new cerebral ischemic lesions using diffusion-weighted magnetic resonance imaging in 95 patients who underwent 98 CAS procedures: 34 using single PercuSurge GuardWire, 31 using double balloon protection, 15 using proximal flow reverse protection devices, 14 using Naviballoon, and 4 using filter anti-embolic devices. Diffusion-weighted imaging was performed preoperatively and postoperatively to evaluate the presence of any new embolic cerebral lesions. Postoperative diffusion-weighted imaging revealed 117 new ischemic lesions. Three patients had new ischemic stroke, two minor and one major, all ipsilateral to the treated carotid artery. The remaining patients had clinically silent ischemia. The incidence of new embolic lesions was lower using the proximal flow reverse protection device than with the double balloon protection (33% vs. 48.4%), but the volume of ipsilateral new ischemic lesions per patient was 136.6 mm(3) vs. 86.9 mm(3), respectively. Neuroprotection with Naviballoon yielded ipsilateral lesions of large volume (86.6 mm(3)) and higher number (5.7 lesions per patient) than using the filter anti-embolic device (34.8 mm(3) and 1 lesion per patient). New cerebral ischemic lesions after neuroprotected CAS are usually silent. The lower incidence of distal ischemia using proximal flow reverse and double balloon protection devices is limited by the larger volume and higher number of ischemic lesions.

  2. Detection of Bacteria by Fluorescence in Situ Hybridization in Culture-Negative Soft Tissue Filler Lesions

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2009-01-01

    BACKGROUND Adverse reactions to polyacrylamide gel occur as swellings or nodules, and controversy exists whether these are due to bacterial infection or an autoimmune reaction to the filler. OBJECTIVES Biopsies from culture-negative long-lasting nodules after injection with different types...... of polyacrylamide gel were examined with a combination of Gram stain and fluorescence in situ hybridization. RESULTS Bacteria were detected in biopsies from seven of eight patients. They inhabited gel and intervening tissue and tended to lie in aggregates. CONCLUSION This study supports the assumption...... that infection with bacteria in aggregates causes culture-negative late adverse reactions to polyacrylamide gel, suggesting a biofilm environment. The authors have indicated no significant interest with commercial supporters....

  3. Dedicated Barrett's surveillance sessions managed by trained endoscopists improve dysplasia detection rate.

    Science.gov (United States)

    Ooi, Joanne; Wilson, Patrick; Walker, Giles; Blaker, Paul; DeMartino, Sabina; O'Donohue, John; Reffitt, David; Lanaspre, Effie; Chang, Fuju; Meenan, John; Dunn, Jason M

    2017-06-01

    Background and study aim  Barrett's esophagus (BE)-associated dysplasia is an important marker for risk of progression to esophageal adenocarcinoma (EAC) and an indication for endoscopic therapy. However, BE surveillance technique is variable. The aim of this study was to assess the effect of dedicated BE surveillance lists on dysplasia detection rate (DDR). Patients and methods  This was a prospective study of patients undergoing BE surveillance at two hospitals - community (UHL) and upper gastrointestinal center (GSTT). Four endoscopists (Group A) were trained in Prague classification, Seattle protocol biopsy technique, and lesion detection prior to performing BE surveillance endoscopies at both sites, with dedicated time slots or lists. The DDR was then compared with historical data from 47 different endoscopists at GSTT and 24 at UHL (Group B) who had undertaken Barrett's surveillance over the preceding 5-year period. Results  A total of 729 patients with BE underwent surveillance endoscopy between 2007 and 2012. There was no significant difference in patient age, sex, or length of BE between the two groups. There was a significant difference in detection rate of confirmed indefinite or low grade dysplasia and high grade dysplasia (HGD)/EAC between the two groups: 18 % (26 /142) Group A vs. 8 % (45/587) in Group B ( P  < 0.001). Documentation of Prague criteria and adherence to the Seattle protocol was significantly higher in Group A. Conclusion  This study demonstrated that a group of trained endoscopists undertaking Barrett's surveillance on dedicated lists had significantly higher DDR than a nonspecialist cohort. These findings support the introduction of dedicated Barrett's surveillance lists. © Georg Thieme Verlag KG Stuttgart · New York.

  4. Case detection rates of impetigo by gender and age.

    Science.gov (United States)

    Kiriakis, Kyriakos P; Tadros, Aline; Dimou, Anastasia; Karamanou, Marianna; Banaka, Fotini; Alexoudi, Iliana

    2012-06-01

    A cross sectional study was carried out (impetigo cases n=265, relative prevalence 5.3%, among 50,237 outpatients). Males predominated in childhood, adulthood and overall (OR 2.0) and exhibited a more protracted susceptibility. Impetigo was more prevalent in summer months. Lesions were located on the head and neck (65.4%), followed by 19.6% on an upper extremity and by 7.5% each on the trunk and a lower extremity.

  5. Tumorsize dependent detection rate of endorectal MRI of prostate cancer-A histopathologic correlation with whole-mount sections in 70 patients with prostate cancer

    International Nuclear Information System (INIS)

    Roethke, Matthias C.; Lichy, Matthias P.; Jurgschat, Leo; Hennenlotter, Joerg; Vogel, Ulrich; Schilling, David; Stenzl, Arnulf; Claussen, Claus D.; Schlemmer, Heinz-Peter

    2011-01-01

    Purpose: To evaluate the value of T2w endorectal MRI (eMRI) for correct detection of tumor foci within the prostate regarding tumor size. Materials and Methods: 70 patients with histologically proven prostate cancer were examined with T2w eMRI before radical prostatectomy at a 1.5 T scanner. For evaluation of eMRI, two radiologists evaluated each tumor focus within the gland. After radical prostatectomy, the prostates were prepared as whole-mount sections, according to transversal T2w eMRI. For each slice, tumor surroundings were marked and compared with eMRI. Based on whole-mount section, 315 slices were evaluated and 533 tumor lesions were documented. Results: Based on the T2w eMRI, 213 tumor lesions were described. In 137/213, histology could prove these lesions. EMRI was able to visualize 0/56 lesions with a maximum size of 2 cm 50/56 (89%). False positive eMRI findings were: 2 cm n = 2. Conclusion: T2w eMRI cannot exclude prostate cancer with lesions smaller 10 mm and 0.4 cm 3 respectively. The detection rate for lesions more than 20 mm (1.6 cm 3 ) is to be considered as high.

  6. Impact of respiratory motion correction and spatial resolution on lesion detection in PET: a simulation study based on real MR dynamic data

    Science.gov (United States)

    Polycarpou, Irene; Tsoumpas, Charalampos; King, Andrew P.; Marsden, Paul K.

    2014-02-01

    The aim of this study is to investigate the impact of respiratory motion correction and spatial resolution on lesion detectability in PET as a function of lesion size and tracer uptake. Real respiratory signals describing different breathing types are combined with a motion model formed from real dynamic MR data to simulate multiple dynamic PET datasets acquired from a continuously moving subject. Lung and liver lesions were simulated with diameters ranging from 6 to 12 mm and lesion to background ratio ranging from 3:1 to 6:1. Projection data for 6 and 3 mm PET scanner resolution were generated using analytic simulations and reconstructed without and with motion correction. Motion correction was achieved using motion compensated image reconstruction. The detectability performance was quantified by a receiver operating characteristic (ROC) analysis obtained using a channelized Hotelling observer and the area under the ROC curve (AUC) was calculated as the figure of merit. The results indicate that respiratory motion limits the detectability of lung and liver lesions, depending on the variation of the breathing cycle length and amplitude. Patients with large quiescent periods had a greater AUC than patients with regular breathing cycles and patients with long-term variability in respiratory cycle or higher motion amplitude. In addition, small (less than 10 mm diameter) or low contrast (3:1) lesions showed the greatest improvement in AUC as a result of applying motion correction. In particular, after applying motion correction the AUC is improved by up to 42% with current PET resolution (i.e. 6 mm) and up to 51% for higher PET resolution (i.e. 3 mm). Finally, the benefit of increasing the scanner resolution is small unless motion correction is applied. This investigation indicates high impact of respiratory motion correction on lesion detectability in PET and highlights the importance of motion correction in order to benefit from the increased resolution of future

  7. Impact of respiratory motion correction and spatial resolution on lesion detection in PET: a simulation study based on real MR dynamic data

    International Nuclear Information System (INIS)

    Polycarpou, Irene; Tsoumpas, Charalampos; King, Andrew P; Marsden, Paul K

    2014-01-01

    The aim of this study is to investigate the impact of respiratory motion correction and spatial resolution on lesion detectability in PET as a function of lesion size and tracer uptake. Real respiratory signals describing different breathing types are combined with a motion model formed from real dynamic MR data to simulate multiple dynamic PET datasets acquired from a continuously moving subject. Lung and liver lesions were simulated with diameters ranging from 6 to 12 mm and lesion to background ratio ranging from 3:1 to 6:1. Projection data for 6 and 3 mm PET scanner resolution were generated using analytic simulations and reconstructed without and with motion correction. Motion correction was achieved using motion compensated image reconstruction. The detectability performance was quantified by a receiver operating characteristic (ROC) analysis obtained using a channelized Hotelling observer and the area under the ROC curve (AUC) was calculated as the figure of merit. The results indicate that respiratory motion limits the detectability of lung and liver lesions, depending on the variation of the breathing cycle length and amplitude. Patients with large quiescent periods had a greater AUC than patients with regular breathing cycles and patients with long-term variability in respiratory cycle or higher motion amplitude. In addition, small (less than 10 mm diameter) or low contrast (3:1) lesions showed the greatest improvement in AUC as a result of applying motion correction. In particular, after applying motion correction the AUC is improved by up to 42% with current PET resolution (i.e. 6 mm) and up to 51% for higher PET resolution (i.e. 3 mm). Finally, the benefit of increasing the scanner resolution is small unless motion correction is applied. This investigation indicates high impact of respiratory motion correction on lesion detectability in PET and highlights the importance of motion correction in order to benefit from the increased resolution of future

  8. Large scale deep learning for computer aided detection of mammographic lesions.

    Science.gov (United States)

    Kooi, Thijs; Litjens, Geert; van Ginneken, Bram; Gubern-Mérida, Albert; Sánchez, Clara I; Mann, Ritse; den Heeten, Ard; Karssemeijer, Nico

    2017-01-01

    Recent advances in machine learning yielded new techniques to train deep neural networks, which resulted in highly successful applications in many pattern recognition tasks such as object detection and speech recognition. In this paper we provide a head-to-head comparison between a state-of-the art in mammography CAD system, relying on a manually designed feature set and a Convolutional Neural Network (CNN), aiming for a system that can ultimately read mammograms independently. Both systems are trained on a large data set of around 45,000 images and results show the CNN outperforms the traditional CAD system at low sensitivity and performs comparable at high sensitivity. We subsequently investigate to what extent features such as location and patient information and commonly used manual features can still complement the network and see improvements at high specificity over the CNN especially with location and context features, which contain information not available to the CNN. Additionally, a reader study was performed, where the network was compared to certified screening radiologists on a patch level and we found no significant difference between the network and the readers. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Photoacoustic detection and optical spectroscopy of high-intensity focused ultrasound-induced thermal lesions in biologic tissue

    Energy Technology Data Exchange (ETDEWEB)

    Alhamami, Mosa; Kolios, Michael C.; Tavakkoli, Jahan, E-mail: jtavakkoli@ryerson.ca [Department of Physics, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3 (Canada)

    2014-05-15

    Purpose: The aims of this study are: (a) to investigate the capability of photoacoustic (PA) method in detecting high-intensity focused ultrasound (HIFU) treatments in muscle tissuesin vitro; and (b) to determine the optical properties of HIFU-treated and native tissues in order to assist in the interpretation of the observed contrast in PA detection of HIFU treatments. Methods: A single-element, spherically concaved HIFU transducer with a centre frequency of 1 MHz was utilized to create thermal lesions in chicken breast tissuesin vitro. To investigate the detectability of HIFU treatments photoacoustically, PA detection was performed at 720 and 845 nm on seven HIFU-treated tissue samples. Within each tissue sample, PA signals were acquired from 22 locations equally divided between two regions of interest within two volumes in tissue – a HIFU-treated volume and an untreated volume. Optical spectroscopy was then carried out on 10 HIFU-treated chicken breast specimens in the wavelength range of 500–900 nm, in 1-nm increments, using a spectrophotometer with an integrating sphere attachment. The authors’ optical spectroscopy raw data (total transmittance and diffuse reflectance) were used to obtain the optical absorption and reduced scattering coefficients of HIFU-induced thermal lesions and native tissues by employing the inverse adding-doubling method. The aforementioned interaction coefficients were subsequently used to calculate the effective attenuation coefficient and light penetration depth of HIFU-treated and native tissues in the wavelength range of 500–900 nm. Results: HIFU-treated tissues produced greater PA signals than native tissues at 720 and 845 nm. At 720 nm, the averaged ratio of the peak-to-peak PA signal amplitude of HIFU-treated tissue to that of native tissue was 3.68 ± 0.25 (mean ± standard error of the mean). At 845 nm, the averaged ratio of the peak-to-peak PA signal amplitude of HIFU-treated tissue to that of native tissue was 3.75

  10. Biometric Quantization through Detection Rate Optimized Bit Allocation

    Directory of Open Access Journals (Sweden)

    C. Chen

    2009-01-01

    Full Text Available Extracting binary strings from real-valued biometric templates is a fundamental step in many biometric template protection systems, such as fuzzy commitment, fuzzy extractor, secure sketch, and helper data systems. Previous work has been focusing on the design of optimal quantization and coding for each single feature component, yet the binary string—concatenation of all coded feature components—is not optimal. In this paper, we present a detection rate optimized bit allocation (DROBA principle, which assigns more bits to discriminative features and fewer bits to nondiscriminative features. We further propose a dynamic programming (DP approach and a greedy search (GS approach to achieve DROBA. Experiments of DROBA on the FVC2000 fingerprint database and the FRGC face database show good performances. As a universal method, DROBA is applicable to arbitrary biometric modalities, such as fingerprint texture, iris, signature, and face. DROBA will bring significant benefits not only to the template protection systems but also to the systems with fast matching requirements or constrained storage capability.

  11. Diagnostic imaging costs before and after digital tomosynthesis implementation in patient management after detection of suspected thoracic lesions on chest radiography.

    Science.gov (United States)

    Quaia, Emilio; Grisi, Guido; Baratella, Elisa; Cuttin, Roberto; Poillucci, Gabriele; Kus, Sara; Cova, Maria Assunta

    2014-02-01

    To evaluate diagnostic imaging costs before and after DTS implementation in patients with suspected thoracic lesions on CXR. Four hundred sixty-five patients (263 male, 202 female; age, 72.47 ± 11.33 years) with suspected thoracic lesion(s) after CXR underwent DTS. Each patient underwent CT when a pulmonary non-calcified lesion was identified by DTS while CT was not performed when a benign pulmonary or extrapulmonary lesion or pseudolesion was identified. The average per-patient imaging cost was calculated by normalising the costs before and after DTS implementation. In 229/465 patients who underwent DTS after suspicious CXR, DTS showed 193 pulmonary lesions and 36 pleural lesions, while in the remaining 236/465 patients, lesions were ruled out as pseudolesions of CXR. Chest CT examination was performed in 127/465 (27 %) patients while in the remaining 338/465 patients (73 %) CXR doubtful findings were resolved by DTS. The average per-patient costs of CXR, DTS and CT were 15.15, 41.55 and 113.66. DTS allowed an annual cost saving of 8,090.2 considering unenhanced CT and 19,298.12 considering contrast-enhanced CT. Considering a DTS reimbursement rate of 62.7 the break even point corresponds to 479 DTS examinations. Per-patient diagnostic imaging costs decreased after DTS implementation in patients with suspected thoracic lesions. • Digital tomosynthesis improves the diagnostic accuracy and confidence in chest radiography • Digital tomosynthesis reduces the need for CT for a suspected pulmonary lesion • Digital tomosynthesis requires a dose level equivalent to that of around two chest radiographies • Digital tomosynthesis produces a significant per-patient saving in diagnostic imaging costs.

  12. ROC evaluation of SPECT myocardial lesion detectability with and without single iteration non-uniform Chang attenuation compensation using an anthropomorphic female phantom

    International Nuclear Information System (INIS)

    Jang, S.; Jaszczak, R.J.; Duke Univ. Medical Center, Durham, NC; Gilland, D.R.; Turkington, T.G.; Coleman, R.E.; Tsui, B.M.W.; Metz, C.E.

    1998-01-01

    The purpose of this work was to evaluate lesion detectability with and without nonuniform attenuation compensation (AC) in myocardial perfusion SPECT imaging in women using an anthropomorphic phantom and receiver operating characteristics (ROC) methodology. Breast attenuation causes artifacts in reconstructed images and may increase the difficulty of diagnosis of myocardial perfusion imaging in women. The null hypothesis tested using the ROC study was that nonuniform AC does not change the lesion detectability in myocardial perfusion SPECT imaging in women. The authors used a filtered backprojection (FBP) reconstruction algorithm and Chang's single iteration method for AC. In conclusion, with the proposed myocardial defect model nuclear medicine physicians demonstrated no significant difference for the detection of the anterior wall defect; however, a greater accuracy for the detection of the inferior wall defect was observed without nonuniform AC than with it. Medical physicists did not demonstrate any statistically significant difference in defect detection accuracy with or without nonuniform AC in the female phantom

  13. Digital breast tomosynthesis (DBT) to characterize MRI-detected additional lesions unidentified at targeted ultrasound in newly diagnosed breast cancer patients

    International Nuclear Information System (INIS)

    Mariscotti, Giovanna; Durando, Manuela; Regini, Elisa; Fornari, Alberto; Fonio, Paolo; Gandini, Giovanni; Houssami, Nehmat; Campanino, Pier Paolo; Bussone, Riccardo; Castellano, Isabella; Sapino, Anna

    2015-01-01

    Preoperative breast magnetic resonance (MR) often generates additional suspicious findings needing further investigations. Targeted breast ultrasound (US) is the standard tool to characterize MR additional lesions. The purpose of this study is to evaluate the potential role of digital breast tomosynthesis (DBT) to characterize MR detected additional findings, unidentified at targeted breast US. This prospective study included women who a) had biopsy-proven, newly diagnosed breast cancers detected at conventional 2D mammography and/or US, referred to breast MR for tumour staging; and b) had DBT if additional MR findings were not detected at targeted ('second look') US. In 520 patients, MR identified 164 (in 114 women, 22 %) additional enhancing lesions. Targeted US identified 114/164 (69.5 %) of these, whereas 50/164 (30.5 %) remained unidentified. DBT identified 32/50 of these cases, increasing the overall characterization of MR detected additional findings to 89.0 % (146/164). Using DBT the identified lesions were significantly more likely to be malignant than benign MR-detected additional lesions (p = 0.04). DBT improves the characterization of additional MR findings not identified at targeted breast US in preoperative breast cancer staging. (orig.)

  14. Digital breast tomosynthesis (DBT) to characterize MRI-detected additional lesions unidentified at targeted ultrasound in newly diagnosed breast cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Mariscotti, Giovanna; Durando, Manuela; Regini, Elisa; Fornari, Alberto; Fonio, Paolo; Gandini, Giovanni [Breast Imaging Service, Radiology - University of Turin, Department of Diagnostic Imaging and Radiotherapy, A.O.U. Citta della Salute e della Scienza, Torino (Italy); Houssami, Nehmat [University of Sydney, Screening and Test Evaluation Program, School of Public Health, Sydney Medical School, Sydney, NSW (Australia); Campanino, Pier Paolo [Ospedale Koelliker, Breast Imaging Service, Torino (Italy); Bussone, Riccardo [A.O.U. Citta della Salute e della Scienza of Turin, SSCVD Breast Surgery. Department of Surgery, Torino (Italy); Castellano, Isabella; Sapino, Anna [University of Turin, Department of Biomedical Sciences and Human Oncology, A.O.U. Citta della Salute e della Scienza, Torino (Italy)

    2015-09-15

    Preoperative breast magnetic resonance (MR) often generates additional suspicious findings needing further investigations. Targeted breast ultrasound (US) is the standard tool to characterize MR additional lesions. The purpose of this study is to evaluate the potential role of digital breast tomosynthesis (DBT) to characterize MR detected additional findings, unidentified at targeted breast US. This prospective study included women who a) had biopsy-proven, newly diagnosed breast cancers detected at conventional 2D mammography and/or US, referred to breast MR for tumour staging; and b) had DBT if additional MR findings were not detected at targeted ('second look') US. In 520 patients, MR identified 164 (in 114 women, 22 %) additional enhancing lesions. Targeted US identified 114/164 (69.5 %) of these, whereas 50/164 (30.5 %) remained unidentified. DBT identified 32/50 of these cases, increasing the overall characterization of MR detected additional findings to 89.0 % (146/164). Using DBT the identified lesions were significantly more likely to be malignant than benign MR-detected additional lesions (p = 0.04). DBT improves the characterization of additional MR findings not identified at targeted breast US in preoperative breast cancer staging. (orig.)

  15. Detection of human cytomegalovirus and Epstein-Barr Virus in symptomatic and asymptomatic apical periodontitis lesions by real-time PCR.

    Science.gov (United States)

    Ozbek, Selcuk-M; Ozbek, Ahmet; Yavuz, Muhammed-Selim

    2013-09-01

    Recent studies have investigated the occurrence of human cytomegalovirus and Epstein-Barr Virus in samples from apical periodontitis lesions and a role in the pathogenesis of this disease has been suggested. Because genotype distribution and seroprevalence of EBV and HCMV differ among populations, it is important to determine the presence of these viruses in endodontic periapical lesions of different populations. The aims of this study were to determine the presence of HCMV and EBV DNAs in samples from Turkish patients with symptomatic and asymptomatic apical periodontitis lesions using real-time polymerase chain reaction method and to evaluate their presence in both symptomatic and asymptomatic apical periodontitis lesions. Periapical samples were collected from 12 asymptomatic and 16 symptomatic periapical lesions in conjunction with apicectomy. HCMV and EBV DNAs were identified in the samples by real-time PCR. The chi-squared test with Yates's correction or the Fisher's exact test was used to analyse the significance of differences. HCMV DNA was detected in 10 of the 16 (62.5%) symptomatic and in five of the 12 (41.7 %) asymptomatic periapical study lesions. The EBV DNA was identified in seven of the 16 (43.7 %) symptomatic and three of the 12 (25 %) asymptomatic periapical lesions. The difference in occurrence of HCMV and EBV DNA between symptomatic and asymptomatic periapical lesions was not statistically significant. (All comparisons have p > 0.05). Our findings suggest that HCMV and EBV is a frequent inhabitant of both symptomatic and asymptomatic apical periodontitis lesions of endodontic origin in Turkish population.

  16. Pursuing shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) for concomitant detection of breast lesions and microcalcifications

    Science.gov (United States)

    Zheng, Chao; Shao, Wanting; Paidi, Santosh Kumar; Han, Bing; Fu, Tong; Wu, Di; Bi, Lirong; Xu, Weiqing; Fan, Zhimin; Barman, Ishan

    2015-10-01

    Although tissue staining followed by morphologic identification remains the gold standard for diagnosis of most cancers, such determinations relying solely on morphology are often hampered by inter- and intra-observer variability. Vibrational spectroscopic techniques, in contrast, offer objective markers for diagnoses and can afford disease detection prior to alterations in cellular and extracellular architecture by furnishing a rapid ``omics''-like view of the biochemical status of the probed specimen. Here, we report a classification approach to concomitantly detect microcalcification status and local pathological state in breast tissue, featuring a combination of vibrational spectroscopy that focuses on the tumor and its microenvironment, and multivariate data analysis of spectral markers reflecting molecular expression. We employ the unprecedented sensitivity and exquisite molecular specificity offered by Au@SiO2 shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) to probe the presence of calcified deposits and distinguish between normal breast tissues, fibroadenoma, atypical ductal hyperplasia, ductal carcinoma in situ (DCIS), and invasive ductal carcinoma (IDC). By correlating the spectra with the corresponding histologic assessment, we developed partial least squares-discriminant analysis derived decision algorithm that provides excellent diagnostic power in the fresh frozen sections (overall accuracy of 99.4% and 93.6% using SHINs for breast lesions with and without microcalcifications, respectively). The performance of this decision algorithm is competitive with or supersedes that of analogous algorithms employing spontaneous Raman spectroscopy while enabling facile detection due to the considerably higher intensity of SHINERS. Our results pave the way for rapid tissue spectral pathology measurements using SHINERS that can offer a novel stain-free route to accurate and economical diagnoses without human interpretation.Although tissue staining

  17. Colposcopic triage methods for detecting cervical intraepithelial neoplasia grade 3 after cytopathological diagnosis of low-grade squamous intraepithelial lesion: a systematic review on diagnostic tests

    Directory of Open Access Journals (Sweden)

    Flávia de Miranda Corrêa

    Full Text Available CONTEXT AND OBJECTIVE: The age-stratified performance of the oncogenic HPV-DNA (human papillomavirus deoxyribonucleic acid test for triage of low-grade squamous intraepithelial lesions (LSIL requires investigation. The objective of this study was to evaluate and compare the age-stratified performance (cutoff point: 35 years of oncogenic HPV-DNA testing and repeated cytological tests, for detecting cervical intraepithelial neoplasia grade 3 (CIN3, in order to triage for LSIL. DESIGN AND SETTING: Systematic review. Studies were identified in nine electronic databases and in the reference lists of the articles retrieved. METHODS: The eligibility criteria consisted of initial cytological findings of LSIL; subsequent oncogenic HPV-DNA testing and repeated cytological tests; and CIN3 detection. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS guidelines were used for quality assessment. Qualitative information synthesis was performed. RESULTS: Out of 7,776 studies, 284 were identified as pertinent and three fulfilled the eligibility criteria. The CIN3 prevalence ranged from 6% to 12%. The HPV-DNA positivity rate ranged from 64% to 83%; sensitivity for CIN3 detection ranged from 95.2% to 100%; and specificity was available in two studies (27% and 52%. The sensitivity of repeated cytological tests, in relation to the threshold for atypical squamous cells of undetermined significance (ASCUS, was available in two studies (33% and 90.8%; and specificity was available in one study (53%. CONCLUSIONS: Currently, there is no scientific evidence available that would prove that colposcopic triage using oncogenic HPV-DNA testing to detect CIN3 performs better than repeated cytological tests, among women with LSIL aged 35 years and over.

  18. Image-processing techniques used in the computer-aided detection of radiographic lesions in anatomic background

    International Nuclear Information System (INIS)

    Giger, M.L.; Doi, K.; MacMahon, H.; Yin, F.F.

    1988-01-01

    The authors developed feature-extraction techniques for use in the computer-aided detection of pulmonary nodules in digital chest images. Use of such a computer-aided detection scheme, which would alert radiologists to the locations of suspected lung nodules, is expected to reduce the number of false-negative diagnoses. False-negative diagnoses (i.e., misses) are a current problem in chest radiology with ''miss-rates'' as high as 30%. This may be due to the camouflaging effect of surrounding anatomic background on the nodule, or to the subjective and varying decision criteria used by radiologists

  19. Differential diagnosis of MRI detected intra cranial space occupying lesions (ICSOLS)-role of 99MTC tetrofosmin cerebral spect

    International Nuclear Information System (INIS)

    Padmal, S.; Sundaram, P.S.; Kumar, S.

    2004-01-01

    Discriminating the correct etiology of Intra Cranial Space Occupying Lesions (ICSOLs) detected by MRI is of paramount importance in deciding the right therapeutic approach. Functional imaging like 99m Tc Tetrofosmin cerebral SPECT (C SPECT) can be used to differentiate malignant from other benign cerebral pathologies. Objective: Our aim was to assess the efficacy of C SPECT in differentiating various etiologies (i.e. Infective / Inflammatory, Neoplastic and Post Radiotherapy changes) of MRI detected ICSOLs. We also aimed to assess the incremental value of quantitative uptake ratios in identifying the exact nature of ICSOLs. Method: 26 Patients (M:F=20:6), age range 28-76 yrs, mean 42±7 yrs were evaluated by 99mTc Tetrofosmin cerebral SPECT. 14/26 patients were HIV positive cases while remaining 12 were treated patients of intracerebral malignancies. All these patients had one or more discrete MRI detected ICSOLs. 6/4 patients with HIV and 4/12 patients in the non HIV group showed more than 1 discrete ICSOLs. 20 mci of 99mTc Tetrofosmin was injected IV .15 min (early) and 2 hrs (delayed) post injection C SPECT images were acquired on a dual head variable angle Gamma camera. After reconstruction, transverse, coronal and sagittal images were co- registered with DICOM online available MRI images using aco- registration software. Focal Tetrofosmin uptake in MRI detected ICSOL was interpreted as abnormal. Tetrofosmin uptake index (Ix) was calculated in early and delayed images as ratio of counts in lesion to that of contra lateral region. A value of more than 1.3 was considered to be abnormal. Persistent Ix of more than 1.3 in initial and delayed images were considered to be malignant while Ix of more or less than 1.3 in initial but less than 1.3 in delayed images was considered to be benign in both groups. Results: In HIV group (14 pts), 4 patients showed an Ix of less than 1.3 in both early and delayed images and 7 patients showed an Ix of more than 1.3 in early but

  20. Brain MR post-gadolinium contrast in multiple sclerosis: the role of magnetization transfer and image subtraction in detecting more enhancing lesions

    Energy Technology Data Exchange (ETDEWEB)

    Gavra, M.M.; Gouliamos, A.D.; Vlahos, L.J. [Department of Radiology, ' ' Aretaieion' ' Hospital,University of Athens Medical School, Athens (Greece); Voumvourakis, C.; Sfagos, C. [Department of Neurology, ' ' Eginiteion' ' Hospital, University of Athens Medical School, Athens (Greece)

    2004-03-01

    Our purpose was to evaluate the role of magnetization transfer and image subtraction in detecting more enhancing lesions in brain MR imaging of patients with multiple sclerosis (MS). Thirty-one MS patients underwent MR imaging of the brain with T1-weighted spin echo sequences without and with magnetization transfer (MT) using a 1.5 T imager. Both sequences were acquired before and after intravenous injection of a paramagnetic contrast agent. Subtraction images in T1-weighted sequences were obtained by subtracting the pre-contrast images from the post-contrast ones. A significant difference was found between the numbers of enhanced areas in post-gadolinium T1-weighted images without and with MT (p=0.020). The post-gadolinium T1-weighted images with MT allowed the detection of an increased (13) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. A significant difference was also found between the numbers of enhanced areas in post-gadolinium T1-weighted images without MT and subtraction images without MT (p=0.020). The subtraction images without MT allowed the detection of an increased (10) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. Magnetization transfer contrast and subtraction techniques appear to be the simplest and least time-consuming applications to improve the conspicuity and detection of contrast-enhancing lesions in patients with MS. (orig.)

  1. Brain MR post-gadolinium contrast in multiple sclerosis: the role of magnetization transfer and image subtraction in detecting more enhancing lesions

    International Nuclear Information System (INIS)

    Gavra, M.M.; Gouliamos, A.D.; Vlahos, L.J.; Voumvourakis, C.; Sfagos, C.

    2004-01-01

    Our purpose was to evaluate the role of magnetization transfer and image subtraction in detecting more enhancing lesions in brain MR imaging of patients with multiple sclerosis (MS). Thirty-one MS patients underwent MR imaging of the brain with T1-weighted spin echo sequences without and with magnetization transfer (MT) using a 1.5 T imager. Both sequences were acquired before and after intravenous injection of a paramagnetic contrast agent. Subtraction images in T1-weighted sequences were obtained by subtracting the pre-contrast images from the post-contrast ones. A significant difference was found between the numbers of enhanced areas in post-gadolinium T1-weighted images without and with MT (p=0.020). The post-gadolinium T1-weighted images with MT allowed the detection of an increased (13) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. A significant difference was also found between the numbers of enhanced areas in post-gadolinium T1-weighted images without MT and subtraction images without MT (p=0.020). The subtraction images without MT allowed the detection of an increased (10) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. Magnetization transfer contrast and subtraction techniques appear to be the simplest and least time-consuming applications to improve the conspicuity and detection of contrast-enhancing lesions in patients with MS. (orig.)

  2. Performance of human observers and an automatic 3-dimensional computer-vision-based locomotion scoring method to detect lameness and hoof lesions in dairy cows

    NARCIS (Netherlands)

    Schlageter-Tello, Andrés; Hertem, Van Tom; Bokkers, Eddie A.M.; Viazzi, Stefano; Bahr, Claudia; Lokhorst, Kees

    2018-01-01

    The objective of this study was to determine if a 3-dimensional computer vision automatic locomotion scoring (3D-ALS) method was able to outperform human observers for classifying cows as lame or nonlame and for detecting cows affected and nonaffected by specific type(s) of hoof lesion. Data

  3. Magnetic resonance imaging at 3.0 tesla detects more lesions in acute optic neuritis than at 1.5 tesla

    DEFF Research Database (Denmark)

    Nielsen, Kirsten; Rostrup, Egill; Frederiksen, Jette L

    2006-01-01

    OBJECTIVE:: We sought to assess whether magnetic resonance imaging (MRI) at 3.0 T detects more brain lesions in acute optic neuritis (ON) than MRI at 1.5 T. MATERIALS AND METHODS:: Twenty-eight patients with acute ON were scanned at both field-strengths using fast-fluid-attenuated inversion recov...

  4. Comparison of the prevalence of human papilloma virus infection in histopathologically confirmed premalignant oral lesions and healthy oral mucosa by brush smear detection.

    Science.gov (United States)

    Dalla Torre, Daniel; Burtscher, Doris; Edlinger, Michael; Sölder, Elisabeth; Widschwendter, Andreas; Rasse, Michael; Puelacher, Wolfgang

    2015-03-01

    The role of human papilloma virus (HPV) infections in oral carcinogenesis is an important topic of research in maxillofacial oncology. Nevertheless, the association between such infections in the oral cavity and the development of oral precancerous lesions remains unclear. The aim of this study was to evaluate the association between oral HPV infections and oral leukoplakia or erythroplakia. The case control study included 118 patients with manifest oral leukoplakia or erythroplakia, who underwent surgical biopsy, including a histopathologic grading of the lesion, and 100 control patients without any oral lesions. HPV detection was achieved with a noninvasive brush smear method (Digene Cervical Sampler, Hybrid Capture II-Test). Logistic regression analysis was performed to assess the associations. A significant association was found between high-risk oral HPV infection and the presence of oral premalignant lesions (P = .001). Among all other evaluated parameters, only smoking showed a significant association with the presence of oral lesions. Oral HPV infections may play a role in the pathogenesis of premalignant oral lesions. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Detection and classification of focal liver lesions in patients with colorectal cancer: Retrospective comparison of diffusion-weighted MR imaging and multi-slice CT

    International Nuclear Information System (INIS)

    Eiber, Matthias; Fingerle, Alexander A.; Brügel, Melanie; Gaa, Jochen; Rummeny, Ernst J.; Holzapfel, Konstantin

    2012-01-01

    Objectives: To compare the diagnostic performance of diffusion-weighted MR imaging (DWI) with multi-slice CT (MS-CT) in the detection and classification of focal liver lesions in patients with colorectal cancer. Methods: In a retrospective study 68 patients who underwent DWI at 1.5 T (b-values of 50, 300 and 600 s/mm 2 ) and contrast-enhanced MS-CT were analysed by two radiologists blinded to the clinical results. Imaging results were correlated with intraoperative surgical and ultrasound findings (n = 24), imaging follow-up or PET (n = 44). Sensitivity of DWI and MS-CT in detection of focal liver lesions was compared on a per-lesion and a per-segment basis. Receiver operator-characteristic (ROC) curves to determine the diagnostic performance and the sensitivities of correctly identifying liver metastases on a segmental base were calculated. Results: For lesion detection, DWI was significantly superior to MS-CT both on a per-lesion (difference in sensitivities for reader 1 and 2 22.65% and 19.06%, p < 0.0001) and a per-segment basis (16.86% and 11.76%, p < 0.0001). Especially lesions smaller than 10 mm were better detected with DWI compared to MS-CT (difference 41.10% and 29.45%, p < 0.0001). ROC-analysis showed superiority for lesions classification (p < 0.0001) of DWI (AUC: 0.949 and 0.951) as compared to MS-CT (AUC: 0.879 and 0.892, p < 0.0001 and p = 0.005). DWI was able to filter out metastatic segments with a higher sensitivity (88.2 and 86.5%) compared to MS-CT (68.0 and 67.4%, p < 0.0001 and p = 0.005, respectively). Conclusion: Compared to MS-CT DWI is both more sensitive in the detection of liver lesions and more accurate in determining the extent of metastatic disease in patients with colorectal cancer and therefore might help to optimize therapeutic management in those patients.

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

    Science.gov (United States)

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

    2011-05-01

    Phantom studies have shown improved lesion detection performance with time-of-flight (TOF) PET. In this study, we evaluate the benefit of fully 3-dimensional, TOF PET in clinical whole-body oncology using human observers to localize and detect lesions in realistic patient anatomic backgrounds. Our hypothesis is that with TOF imaging we achieve improved lesion detection and localization for clinically challenging tasks, with a bigger impact in large patients. One hundred patient studies with normal (18)F-FDG uptake were chosen. Spheres (diameter, 10 mm) were imaged in air at variable locations in the scanner field of view corresponding to lung and liver locations within each patient. Sphere data were corrected for attenuation and merged with patient data to produce fused list-mode data files with lesions added to normal-uptake scans. All list files were reconstructed with full corrections and with or without the TOF kernel using a list-mode iterative algorithm. The images were presented to readers to localize and report the presence or absence of a lesion and their confidence level. The interpretation results were then analyzed to calculate the probability of correct localization and detection, and the area under the localized receiver operating characteristic (LROC) curve. The results were analyzed as a function of scan time per bed position, patient body mass index (BMI patient sizes. With TOF imaging, there was a bigger increase in the area under the LROC curve for larger patients (BMI ≥ 26). Finally, we saw smaller differences in the area under the LROC curve for large and small patients when longer scan times were combined with TOF imaging. A combination of longer scan time (3 min in this study) and TOF imaging provides the best performance for imaging large patients or a low-uptake lesion in small or large patients. This imaging protocol also provides similar performance for all patient sizes for lesions in the same organ type with similar relative uptake

  7. Breast cancer detection rates using four different types of mammography detectors

    Energy Technology Data Exchange (ETDEWEB)

    Mackenzie, Alistair; Warren, Lucy M.; Dance, David R.; Young, Kenneth C. [Royal Surrey County Hospital, National Coordinating Centre for the Physics in Mammography (NCCPM), Guildford (United Kingdom); University of Surrey, Department of Physics, Guildford (United Kingdom); Wallis, Matthew G. [Cambridge University Hospitals NHS Foundation Trust, Cambridge (United Kingdom); NIHR Cambridge Biomedical Research Centre, Cambridge Breast Unit, Cambridge (United Kingdom); Cooke, Julie [Jarvis Breast Screening and Diagnostic Centre, Guildford (United Kingdom); Given-Wilson, Rosalind M. [St George' s Healthcare NHS Trust, Department of Radiology, London (United Kingdom); Chakraborty, Dev P. [University of Pittsburgh, Department of Radiology, Pittsburgh, PA (United States); Halling-Brown, Mark D. [Royal Surrey County Hospital, Scientific Computing, Department of Medical Physics, Guildford (United Kingdom); Looney, Padraig T. [Royal Surrey County Hospital, National Coordinating Centre for the Physics in Mammography (NCCPM), Guildford (United Kingdom)

    2016-03-15

    To compare the performance of different types of detectors in breast cancer detection. A mammography image set containing subtle malignant non-calcification lesions, biopsy-proven benign lesions, simulated malignant calcification clusters and normals was acquired using amorphous-selenium (a-Se) detectors. The images were adapted to simulate four types of detectors at the same radiation dose: digital radiography (DR) detectors with a-Se and caesium iodide (CsI) convertors, and computed radiography (CR) detectors with a powder phosphor (PIP) and a needle phosphor (NIP). Seven observers marked suspicious and benign lesions. Analysis was undertaken using jackknife alternative free-response receiver operating characteristics weighted figure of merit (FoM). The cancer detection fraction (CDF) was estimated for a representative image set from screening. No significant differences in the FoMs between the DR detectors were measured. For calcification clusters and non-calcification lesions, both CR detectors' FoMs were significantly lower than for DR detectors. The calcification cluster's FoM for CR NIP was significantly better than for CR PIP. The estimated CDFs with CR PIP and CR NIP detectors were up to 15 % and 22 % lower, respectively, than for DR detectors. Cancer detection is affected by detector type, and the use of CR in mammography should be reconsidered. (orig.)

  8. Is a single direct MR arthrography series in ABER position as accurate in detecting anteroinferior labroligamentous lesions as conventional MR arthography?

    Energy Technology Data Exchange (ETDEWEB)

    Schreinemachers, Saskia A.; Hulst, Victor P.M. van der; Woude, Henk-Jan van der [Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Jaap Willems, W. [Onze Lieve Vrouwe Gasthuis, Orthopaedic Surgery, Amsterdam (Netherlands); Bipat, Shandra [University of Amsterdam, Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands)

    2009-07-15

    The purpose of this study is to retrospectively compare accuracy of single magnetic resonance (MR) arthrography series in Abduction External Rotation (ABER) with conventional MR arthrography for detection and characterisation of anteroinferior labroligamentous lesions, with arthroscopy as reference standard. Inter-observer variability of both protocols was determined. Institutional review board approval was obtained; informed consent was waived. MR arthrograms, including oblique axial fat suppressed T1-weighted images in ABER position and conventional imaging directions of 250 patients (170 men, 80 women; mean age, 36 years), were retrospectively and independently evaluated by three reviewers. Reviewers were blinded to clinical information and arthroscopic results. Labroligamentous lesions were registered in both ABER and MRa. The lesions were sub-classified (Bankart, Perthes, anterior labrum periosteal sleeve avulsion (ALPSA) or lesions not otherwise specified). Inter-observer agreement was assessed by Kappa statistics for all 250 patients. Ninety-two of 250 patients underwent arthroscopy. Sensitivity, specificity and accuracy of ABER versus conventional MR arthrography were calculated and compared using paired McNemar test. Kappa values of the ABER and conventional MR arthrography ranged from 0.44 to 0.56 and 0.44 to 0.62, respectively. According to arthroscopy, 45 of 92 patients had an intact anteroinferior labrum, and in 44 patients, a labroligamentous lesion (eight Bankart, seven Perthes, 29 ALPSA and three lesions not otherwise specified) was diagnosed. There were no statistically significant differences between ABER and conventional MR arthrography regarding sensitivity (85-89%, 89-96%), specificity (82-91%, 84-89%) and overall accuracy (50-62%, 53-63%). The results of a single MR arthrography series in ABER position are comparable with those of conventional MR arthrography for detecting anteroinferior labroligamentous lesions. (orig.)

  9. Dual contrast enhanced magnetic resonance imaging of the liver with superparamagnetic iron oxide followed by gadolinium for lesion detection and characterization

    International Nuclear Information System (INIS)

    Kubaska, Samantha; Sahani, Dushyant V.; Saini, Sanjay; Hahn, Peter F.; Halpern, Elkan

    2001-01-01

    AIM: Iron oxide contrast agents are useful for lesion detection, and extracellular gadolinium chelates are advocated for lesion characterization. We undertook a study to determine if dual contrast enhanced liver imaging with sequential use of ferumoxides particles and gadolinium (Gd)-DTPA can be performed in the same imaging protocol. MATERIALS AND METHODS: Sixteen patients underwent dual contrast magnetic resonance imaging (MRI) of the liver for evaluation of known/suspected focal lesions which included, metastases (n = 5), hepatocellular carcinoma (HCC;n = 3), cholangiocharcinoma(n = 1) and focal nodular hyperplasia (FNH;n = 3). Pre- and post-iron oxide T1-weighted gradient recalled echo (GRE) and T2-weighted fast spin echo (FSE) sequences were obtained, followed by post-Gd-DTPA (0.1 mmol/kg) multi-phase dynamic T1-weighted out-of-phase GRE imaging. Images were analysed in a blinded fashion by three experts using a three-point scoring system for lesion conspicuity on pre- and post-iron oxide T1 images as well as for reader's confidence in characterizing liver lesions on post Gd-DTPA T1 images. RESULTS: No statistically significant difference in lesion conspicuity was observed on pre- and post-iron oxide T1-GRE images in this small study cohort. The presence of iron oxide did not appreciably diminish image quality of post-gadolinium sequences and did not prevent characterization of liver lesions. CONCLUSION: Our results suggest that characterization of focal liver lesion with Gd-enhanced liver MRI is still possible following iron oxide enhanced imaging. Kubaska, S. et al. (2001)

  10. Accuracy of CT enterography and magnetic resonance enterography imaging to detect lesions preoperatively in patients undergoing surgery for Crohn's disease.

    Science.gov (United States)

    Seastedt, Kenneth P; Trencheva, Koiana; Michelassi, Fabrizio; Alsaleh, Doaa; Milsom, Jeffrey W; Sonoda, Toyooki; Lee, Sang W; Nandakumar, Govind

    2014-12-01

    CT enterography and magnetic resonance enterography have emerged as first-line imaging technologies for the evaluation of the gastrointestinal tract in Crohn's disease. The purpose of this work was to evaluate the accuracy of these imaging modalities to identify Crohn's disease lesions preoperatively. This was a retrospective chart review. The study was conducted at a single institution. Seventy-six patients with Crohn's disease with preoperative CT enterography and/or magnetic resonance enterography were included in the study. The number of stenoses, fistulas, and abscesses on CT enterography and/or magnetic resonance enterography before surgery were compared with operative findings. Forty patients (53%) were women, 46 (60%) underwent surgery for recurrent Crohn's disease, and 46 (57%) had previous abdominal surgery. Thirty-six (47%) had a preoperative CT enterography and 43 (57%) had a preoperative magnetic resonance enterography. CT enterography sensitivity was 75% for stenosis and 50% for fistula. MRE sensitivity was 68% for stenosis and 60% for fistula. The negative predictive values of CT enterography and magnetic resonance enterography for stenosis were very low (54% and 65%) and were 85% and 81% for fistula. CT enterography had 76% accuracy for stenosis and 79% for fistula; magnetic resonance enterography had 78% accuracy for stenosis and 85% for fistula. Both were accurate for abscess. False-negative rates for CT enterography were 50% for fistula and 25% for stenosis. False-negative rates for magnetic resonance enterography were 40% for fistula and 32% for stenosis. Unexpected intraoperative findings led to modification of the planned surgical procedure in 20 patients (26%). This study was limited by its small sample size, its retrospective nature, and that some studies were performed at outside institutions. CT enterography and magnetic resonance enterography in patients with Crohn's disease were accurate for the identification of abscesses but not for

  11. Self-organizing neural networks for automatic detection and classification of contrast-enhancing lesions in dynamic MR-mammography; Selbstorganisierende neuronale Netze zur automatischen Detektion und Klassifikation von Kontrast(mittel)-verstaerkten Laesionen in der dynamischen MR-Mammographie

    Energy Technology Data Exchange (ETDEWEB)

    Vomweg, T.W.; Teifke, A.; Kauczor, H.U.; Achenbach, T.; Rieker, O.; Schreiber, W.G.; Heitmann, K.R.; Beier, T.; Thelen, M. [Klinik und Poliklinik fuer Radiologie, Klinikum der Univ. Mainz (Germany)

    2005-05-01

    Purpose: Investigation and statistical evaluation of 'Self-Organizing Maps', a special type of neural networks in the field of artificial intelligence, classifying contrast enhancing lesions in dynamic MR-mammography. Material and Methods: 176 investigations with proven histology after core biopsy or operation were randomly divided into two groups. Several Self-Organizing Maps were trained by investigations of the first group to detect and classify contrast enhancing lesions in dynamic MR-mammography. Each single pixel's signal/time curve of all patients within the second group was analyzed by the Self-Organizing Maps. The likelihood of malignancy was visualized by color overlays on the MR-images. At last assessment of contrast-enhancing lesions by each different network was rated visually and evaluated statistically. Results: A well balanced neural network achieved a sensitivity of 90.5% and a specificity of 72.2% in predicting malignancy of 88 enhancing lesions. Detailed analysis of false-positive results revealed that every second fibroadenoma showed a 'typical malignant' signal/time curve without any chance to differentiate between fibroadenomas and malignant tissue regarding contrast enhancement alone; but this special group of lesions was represented by a well-defined area of the Self-Organizing Map. Discussion: Self-Organizing Maps are capable of classifying a dynamic signal/time curve as 'typical benign' or 'typical malignant'. Therefore, they can be used as second opinion. In view of the now known localization of fibroadenomas enhancing like malignant tumors at the Self-Organizing Map, these lesions could be passed to further analysis by additional post-processing elements (e.g., based on T2-weighted series or morphology analysis) in the future. (orig.)

  12. The diagnostic value of magnetic resonance arthrography of the shoulder in detection and grading of SLAP lesions: Comparison with arthroscopic findings

    International Nuclear Information System (INIS)

    Amin, Mohammed Farghally; Youssef, Ahmed Omar

    2012-01-01

    Purpose: The purpose of the study is to determine the usefulness of magnetic resonance arthrography (MRA) in diagnosis and grading of superior labrum anterior to posterior (SLAP) lesions of the Glenoid Labrum Compared with surgery Material and methods: This was a prospective study including fifty nine clinically diagnosed SLAP patients. The study was done during the period from January 2008 to June 2010. All patients were submitted to history taking, clinical examination and conventional MRI examination of the shoulder, MRA was done in patients with negative conventional MRI, all of these patients underwent arthroscopy for diagnosis wither open or arthroscopy for diagnosis and treatment and results were compared with MRA findings. Main outcome measures: Sensitivity, specificity, positive and negative predictive values, and overall accuracy of MR arthrography in detection and grading of SLAP lesions of the gelnoid labrum. Results: Out of fifty nine patients, 25 patients had positive MR findings in conventional MRI, and 34 patients had negative MR findings, who underwent MR arthrography; 10 out of them had normal arthrogram (only 6 of them underwent arthroscopy), 22 had SLAP (superior labrum anterior to posterior) lesions, one had Bankart's lesion and one had internal impingement syndrome. These results were compared with arthroscopy results. The overall sensitivity of MRA in detection of SLAP lesions was 90% while the specificity was 50%, negative predictive value (NPV) was 66.6% and positive predicative value (PPV) was 81.8%. MRA and arthroscopy results were concurrent in 79.3% patients. Conclusion: MR arthrography is a sensitive minimally invasive technique for detection and grading of SLAP lesions, it can help in avoiding patients unnecessary diagnostic arthroscopy

  13. The diagnostic value of magnetic resonance arthrography of the shoulder in detection and grading of SLAP lesions: Comparison with arthroscopic findings

    Energy Technology Data Exchange (ETDEWEB)

    Amin, Mohammed Farghally, E-mail: Mohammed_amin37@yahoo.com [Department of Radiodiagnosis ElMinya University, ElMinya High Road, ElMinya (Egypt); Youssef, Ahmed Omar [Department of Orthropedic Surgery El Minya University, ElMinya (Egypt)

    2012-09-15

    Purpose: The purpose of the study is to determine the usefulness of magnetic resonance arthrography (MRA) in diagnosis and grading of superior labrum anterior to posterior (SLAP) lesions of the Glenoid Labrum Compared with surgery Material and methods: This was a prospective study including fifty nine clinically diagnosed SLAP patients. The study was done during the period from January 2008 to June 2010. All patients were submitted to history taking, clinical examination and conventional MRI examination of the shoulder, MRA was done in patients with negative conventional MRI, all of these patients underwent arthroscopy for diagnosis wither open or arthroscopy for diagnosis and treatment and results were compared with MRA findings. Main outcome measures: Sensitivity, specificity, positive and negative predictive values, and overall accuracy of MR arthrography in detection and grading of SLAP lesions of the gelnoid labrum. Results: Out of fifty nine patients, 25 patients had positive MR findings in conventional MRI, and 34 patients had negative MR findings, who underwent MR arthrography; 10 out of them had normal arthrogram (only 6 of them underwent arthroscopy), 22 had SLAP (superior labrum anterior to posterior) lesions, one had Bankart's lesion and one had internal impingement syndrome. These results were compared with arthroscopy results. The overall sensitivity of MRA in detection of SLAP lesions was 90% while the specificity was 50%, negative predictive value (NPV) was 66.6% and positive predicative value (PPV) was 81.8%. MRA and arthroscopy results were concurrent in 79.3% patients. Conclusion: MR arthrography is a sensitive minimally invasive technique for detection and grading of SLAP lesions, it can help in avoiding patients unnecessary diagnostic arthroscopy.

  14. Incidentally detected enhancing lesions found in breast MRI: analysis of apparent diffusion coefficient and T2 signal intensity significantly improves specificity

    Energy Technology Data Exchange (ETDEWEB)

    Arponen, Otso; Masarwah, Amro; Taina, Mikko [Kuopio University Hospital, Kuopio University Hospital, Diagnostic Imaging Centre, Department of Clinical Radiology, PO Box 1777, Kuopio (Finland); Kuopio University Hospital, University of Eastern Finland, Institute of Clinical Medicine, School of Medicine, Department of Clinical Radiology, PO Box 1777, Kuopio (Finland); Sutela, Anna; Koenoenen, Mervi; Hakumaeki, Juhana; Sudah, Mazen [Kuopio University Hospital, Kuopio University Hospital, Diagnostic Imaging Centre, Department of Clinical Radiology, PO Box 1777, Kuopio (Finland); Sironen, Reijo [Kuopio University Hospital, Kuopio University Hospital, Department of Pathology, PO Box 1777, Kuopio (Finland); Kuopio University Hospital, University of Eastern Finland, Institute of Clinical Medicine, School of Medicine, Clinical Pathology and Forensic Medicine, PO Box 1777, Kuopio (Finland); University of Eastern Finland, Cancer Center of Eastern Finland, Kuopio (Finland); Vanninen, Ritva [Kuopio University Hospital, Kuopio University Hospital, Diagnostic Imaging Centre, Department of Clinical Radiology, PO Box 1777, Kuopio (Finland); Kuopio University Hospital, University of Eastern Finland, Institute of Clinical Medicine, School of Medicine, Department of Clinical Radiology, PO Box 1777, Kuopio (Finland); University of Eastern Finland, Cancer Center of Eastern Finland, Kuopio (Finland)

    2016-12-15

    To evaluate the value of adding T2- and diffusion-weighted imaging (DWI) to the BI-RADS registered classification in MRI-detected lesions. This retrospective study included 112 consecutive patients who underwent 3.0T structural breast MRI with T2- and DWI on the basis of EUSOMA recommendations. Morphological and kinetic features, T2 signal intensity (T2 SI) and apparent diffusion coefficient (ADC) findings were assessed. Thirty-three (29.5 %) patients (mean age 57.0 ± 12.7 years) had 36 primarily MRI-detected incidental lesions of which 16 (44.4 %) proved to be malignant. No single morphological or kinetic feature was associated with malignancy. Both low T2 SI (P = 0.009) and low ADC values (≤0.87 x 10{sup -3} mm{sup 2}s{sup -1}, P < 0.001) yielded high specificity (80.0 %/80.0 %). The BI-RADS classification supplemented with information from DWI and T2-WI improved the diagnostic performance of the BI-RADS classification as sensitivity remained 100 % and specificity improved from 30 % to 65.0 %. The numbers of false positive lesions declined from 39 % (N = 14) to 19 % (N = 7). MRI-detected incidental lesions may be challenging to characterize as they have few specific malignancy indicating features. The specificity of MRI can be improved by incorporating T2 SI and ADC values into the BI-RADS assessment. (orig.)

  15. Prevalence of renal lesions in slaughtered cattle in Shiraz, Iran, and detection of Leptospira in them by nested PCR-RFLP.

    Science.gov (United States)

    Taghadosi, Vahideh; Hosseinzadeh, Saeid; Shekarforoush, Seyed Shahram; Samiei, Azadeh

    2016-12-01

    Renal diseases in cattle are frequently not recognized due to the subclinical conditions. Some species of Leptospira are the main cause of infectious agents that damage the kidneys and lead to abortion and economic losses in cattle and are also of major concern in the public health. This study was aimed to assess the prevalence of renal lesions of slaughtered cattle in the Shiraz abattoir and to determine the correlation between rejected kidneys and infection with Leptospira using nested PCR-restriction fragment length polymorphism (RFLP) techniques. Out of 1000 inspected animals, 205 (20.5 %) revealed the renal lesions. Chronic nephritis (7.5 %), white-spotted kidney (7.3 %), and petechial hemorrhage (3.5 %) were the most prevalent forms of the lesions. A direct correlation between increasing the age and significant increase in the rate of lesions was also observed (P = 0.03). Using nested PCR-RFLP assay, 40.8 % of the tested kidneys were turned to be infected to the pathogenic species of Leptospira. The risk of infection of the kidneys with white spot to pathogenic species of Leptospira (53.8 %) was more than that of the kidneys with other lesions (25.0 %) (P = 0.014). The odd ratio indicates that the kidneys with white spot lesions are likely to be infected with pathogenic species of Leptospira, five times greater than other lesions. This study showed that renal lesions especially white-spotted kidney, which were considerably associated with Leptospira in slaughtered cattle in Shiraz, were very high. This is important in terms of public health and in particular, increases the risk of transmission of disease to human specially in the high-risk careers including farmers, veterinarians, and abattoir workers.

  16. Malignancy rates and diagnostic performance of the Bosniak classification for the diagnosis of cystic renal lesions in computed tomography - a systematic review and meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sevcenco, Sabina; Shariat, Shahrokh F. [Medical University of Vienna, Department of Urology, Vienna (Austria); Spick, Claudio; Helbich, Thomas H.; Baltzer, Pascal A. [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, General Hospital Vienna, Vienna (Austria); Heinz, Gertraud [University Hospital of Sankt-Poelten, Department of Radiology, Poelten (Austria); Klingler, Hans C. [Wilhelminenspital, Department of Urology, Vienna (Austria); Rauchenwald, Michael [Donauspital, Department of Urology, Vienna (Austria)

    2017-06-15

    To systematically review the literature on the Bosniak classification system in CT to determine its diagnostic performance to diagnose malignant cystic lesions and the prevalence of malignancy in Bosniak categories. A predefined database search was performed from 1 January 1986 to 18 January 2016. Two independent reviewers extracted data on malignancy rates in Bosniak categories and several covariates using predefined criteria. Study quality was assessed using QUADAS-2. Meta-analysis included data pooling, subgroup analyses, meta-regression and investigation of publication bias. A total of 35 studies, which included 2,578 lesions, were investigated. Data on observer experience, inter-observer variation and technical CT standards were insufficiently reported. The pooled rate of malignancy increased from Bosniak I (3.2 %, 95 % CI 0-6.8, I{sup 2} = 5 %) to Bosniak II (6 %, 95 % CI 2.7-9.3, I{sup 2} = 32 %), IIF (6.7 %, 95 % CI 5-8.4, I{sup 2} = 0 %), III (55.1 %, 95 % CI 45.7-64.5, I{sup 2} = 89 %) and IV (91 %, 95 % CI 87.7-94.2, I{sup 2} = 36). Several study design-related influences on malignancy rates and subsequent diagnostic performance indices were identified. The Bosniak classification is an accurate tool with which to stratify the risk of malignancy in renal cystic lesions. (orig.)

  17. Comparison of 3- and 20-Gradient Direction Diffusion-Weighted Imaging in a Clinical Subacute Cohort of Patients with Transient Ischemic Attack: Application of Standard Vendor Protocols for Lesion Detection and Final Infarct Size Projection

    Directory of Open Access Journals (Sweden)

    Inger Havsteen

    2017-12-01

    Full Text Available ObjectiveDiffusion tensor imaging may aid brain ischemia assessment but is more time consuming than conventional diffusion-weighted imaging (DWI. We compared 3-gradient direction DWI (3DWI and 20-gradient direction DWI (20DWI standard vendor protocols in a hospital-based prospective cohort of patients with transient ischemic attack (TIA for lesion detection, lesion brightness, predictability of persisting infarction, and final infarct size.MethodsWe performed 3T-magnetic resonance imaging including diffusion and T2-fluid attenuated inversion recovery (FLAIR within 72 h and 8 weeks after ictus. Qualitative lesion brightness was assessed by visual inspection. We measured lesion area and brightness with manual regions of interest and compared with homologous normal tissue.Results117 patients with clinical TIA showed 78 DWI lesions. 2 lesions showed only on 3DWI. No lesions were uniquely 20DWI positive. 3DWI was visually brightest for 34 lesions. 12 lesions were brightest on 20DWI. The median 3DWI lesion area was larger for lesions equally bright, or brightest on 20DWI [median (IQR 39 (18–95 versus 18 (10–34 mm2, P = 0.007]. 3DWI showed highest measured relative lesion signal intensity [median (IQR 0.77 (0.48–1.17 versus 0.58 (0.34–0.81, P = 0.0006]. 3DWI relative lesion signal intensity was not correlated to absolute signal intensity, but 20DWI performed less well for low-contrast lesions. 3DWI lesion size was an independent predictor of persistent infarction. 3-gradient direction apparent diffusion coefficient areas were closest to 8-week FLAIR infarct size.Conclusion3DWI detected more lesions and had higher relative lesion SI than 20DWI. 20DWI appeared blurred and did not add information.Clinical Trial Registrationhttp://www.clinicaltrials.gov. Unique Identifier NCT01531946.

  18. Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia and Prevotella nigrescens in endodontic lesions detected by culture and by PCR.

    Science.gov (United States)

    Gomes, B P F A; Jacinto, R C; Pinheiro, E T; Sousa, E L R; Zaia, A A; Ferraz, C C R; Souza-Filho, F J

    2005-08-01

    he aim of this study was to investigate the presence of four black-pigmented bacteria, Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia and Prevotella nigrescens, in endodontic infections by culture and polymerase chain reaction (PCR) analyses. Microbial samples were obtained from 50 teeth with untreated necrotic pulps (primary infection) and from 50 teeth with failing endodontic treatment (secondary infection). Microbiological strict anaerobic techniques were used for serial dilution, plating, incubation, and identification. For PCR detection, the samples were analyzed using species-specific primers of 16S rDNA and the downstream intergenic spacer region. Culture and PCR detected the test species in 13/100 and 50/100 of the study teeth, respectively. The organisms were cultured from 11/50 (22%) of primarily infected root canal samples and from 2/50 (4%) of secondary root canal samples. PCR detection identified the target species in 32/50 (64%) and 18/50 (36%) of primary and secondary infections, respectively. P. gingivalis was rarely isolated by culture methods (1%), but was the most frequently identified test species by PCR (38%). Similarly, P. endodontalis was not recovered by culture from any tooth studied, but was detected by PCR in 25% of the sampled teeth. PCR-based identification also showed higher detection rates of P. intermedia (33%) and P. nigrescens (22%) than culture (13%). In conclusion, P. gingivalis, P. endodontalis, P. intermedia, and P. nigrescens were identified more frequently in teeth with necrotic pulp than in teeth with failing endodontic treatment. Also, a higher frequency of black-pigmented species was detected by PCR than by culture.

  19. Effect of adding screening ultrasonography to screening mammography on patient recall and cancer detection rates: A retrospective study in Japan

    International Nuclear Information System (INIS)

    Tohno, Eriko; Umemoto, Takeshi; Sasaki, Kyoko; Morishima, Isamu; Ueno, Ei

    2013-01-01

    Purpose: To determine whether adding screening ultrasonography to screening mammography can reduce patient recall rates and increase cancer detection rates. Materials and methods: We analyzed the results of mammography and ultrasonography breast screenings performed at the Total Health Evaluation Center Tsukuba, Japan, between April 2011 and March 2012. We also reviewed the modalities and results of diagnostic examinations from women with mammographic abnormalities who visited the Tsukuba Medical Center Hospital for further testing. Results: Of 11,753 women screened, cancer was diagnosed in 10 (0.22%) of the 4529 participants who underwent mammography alone, 23 (0.37%) of the 6250 participants who underwent ultrasonography alone, and 5 (0.51%) of the 974 participants who underwent mammography and ultrasonography. The recall rate due to mammographic abnormalities was 4.9% for women screened only with mammography and 2.6% for those screened with both modalities. The cancer detection rate was 0.22% for women screened only with mammography (positive predictive value, 4.5%) and 0.31% for those screened with both modalities (positive predictive value, 12.0%). Of the 211 lesions presenting as mammographic abnormalities investigated further, diagnostic ultrasonography found no abnormalities in 63 (29.9%) and benign findings in 69 (33.7%). The rest 36.4% needed mammography, cytological or histological examinations or follow-up in addition to diagnostic ultrasonography. Conclusions: It is possible to reduce the recall rate in screening mammography by combining mammography and ultrasonography for breast screening

  20. Breath-hold [68Ga]DOTA-TOC PET/CT in neuroendocrine tumors: detection of additional lesions and effects on quantitative parameters.

    Science.gov (United States)

    Zirnsak, Mariana; Bärwolf, Robert; Freesmeyer, Martin

    2016-11-08

    Respiratory motion during PET/CT acquisition generates artifacts in the form of breath-related blurring, which influences the lesion detectability and diagnostic accuracy. The goal of this study was to verify whether breath-hold [68Ga]DOTA-TOC PET/CT (bhPET) allows detection of additional foci compared to free-breathing PET/CT (fbPET), and to assess the impact of breath-holding on standard uptake values (SUV) and isocontoured volume (Vic40) in patients with neuroendocrine tumors (NET). Patients with NET (n=39) were included in this study. BhPET and fbPET characteristics of 96 lesions were compared, and correlated with standard contrast-enhanced (ce) CT and MRI for lesion verification. Quantitative parameters SUV (max and mean) and Vic40 were assessed for both methods and evaluated by linear regression and Spearman's correlation. The impact of lesion size, localization and time interval between investigations was also analyzed. bhPET identified one additional metastasis not seen at fbPET but visible at ceMRI. Another additional bhPET focus did not have a morphological correlate. At bhPET, the SUVmax and SUVmean proved significantly higher and the Vic40 significantly lower than at fbPET. Lesion size, localization and time intervals did not impact significantly on SUV or Vic40. Currently, routine use of breath-hold [68Ga]DOTA-TOC PET/CT cannot be recommended as only one additional lesion was identified. Therefore, bhPET has currently no indication in patients with NET. If technical improvements regarding PET/CT scanner sensitivity are available, bhPET should be reevaluated in the future.

  1. Gd-EOB-DTPA-enhanced 3.0-Tesla MRI findings for the preoperative detection of focal liver lesions: Comparison with iodine-enhanced multi-detector computed tomography

    Science.gov (United States)

    Park, Hyong-Hu; Goo, Eun-Hoe; Im, In-Chul; Lee, Jae-Seung; Kim, Moon-Jib; Kwak, Byung-Joon; Chung, Woon-Kwan; Dong, Kyung-Rae

    2012-12-01

    The safety of gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic-acid (Gd-EOB-DTPA) has been confirmed, but more study is needed to assess the diagnostic accuracy of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) in patients with a hepatocellular carcinoma (HCC) for whom surgical treatment is considered or with a metastatic hepatoma. Research is also needed to examine the rate of detection of hepatic lesions compared to multi-detector computed tomography (MDCT), which is used most frequently to localize and characterize a HCC. Gd-EOB-DTPA-enhanced MRI and iodine-enhanced MDCT imaging were compared for the preoperative detection of focal liver lesions. The clinical usefulness of each method was examined. The current study enrolled 79 patients with focal liver lesions who preoperatively underwent MRI and MDCT. In these patients, there was less than one month between the two diagnostic modalities. Imaging data were taken before and after contrast enhancement in both methods. To evaluate the images, we analyzed the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) in the lesions and the liver parenchyma. To compare the sensitivity of the two methods, we performed a quantitative analysis of the percentage signal intensity of the liver (PSIL) on a high resolution picture archiving and communication system (PACS) monitor (paired-samples t-test, p DTPA-enhanced MRI findings and the iodine-enhanced MDCT by using an adjusted x2 test. The SNRs, CNRs, and PSIL all had a greater detection rate in Gd-EOB-DTPA enhanced MRI than in iodine-enhanced MDCT. Hepatocyte-selective uptake was observed 20 minutes after the injection in the focal nodular hyperplasia (FNH, 9/9), adenoma (9/10), and highly-differentiated HCC (grade G1, 27/30). Rim enhancement was detected in all metastases (30/30). During the arterial and the delayed phases, good overall agreement between the gadoxetic-acid-enhanced MR and CT was observed (x2 test, p DTPA-enhanced MRI had a higher

  2. Clinical significance of atypical squamous cells of undetermined significance in detecting preinvasive cervical lesions in post- menopausal Turkish women.

    Science.gov (United States)

    Tokmak, Aytekin; Guzel, Ali Irfan; Ozgu, Emre; Oz, Murat; Akbay, Serap; Erkaya, Salim; Gungor, Tayfun

    2014-01-01

    To evaluate the clinical significance of atypical squamous cells of undetermined significance (ASCUS) in PAP test in post-menopausal women and compare with reproductive age women. A total of 367 patients who referred to our gynecologic oncology clinic were included to the study between September 2012 and August 2013. Data for 164 post-menopausal (group 1) and 203 pre-menopausal (group 2) women with ASCUS cytology were evaluated retrospectively. Immediate colposcopy and endocervical curettage was performed for both groups and conization for all women with a result suggestive of CIN2-3. Histopathological results and demographic features of patients were compared between the two groups. Mean age of the patients was 54.6±6.5 years in group 1 and 38±6.6 years in group 2. Some 14 (8.5%) of post- menopausal women and 36 (17.7%) of pre-menopausal women were current smokers (p=011). Totals of 38 (23.2%) post-menopausal and 64 (31.5%) pre-menopausal women were assessed for HPV-DNA. High risk HPV was detected in 7 (4.3%) and 21 (10.3%), respectively (p=0.029). Final histopathological results recorded were normal cervix, low grade cervical intra-epithelial neoplasia (CIN 1), and high grade cervical intra-epithelial neoplasia (CIN2-3). In group 1 results were 84.8%, 12.2% and 1.8%, respectively, and in group 2 were 71.9%, 23.2% and 4.9%. There were no cases of micro invasive or invasive cervical carcinoma in either group. Two cases were detected as endometrial carcinoma in the menopausal group (1.2%). In current study we found that preinvasive lesions were statistically significantly higher in pre-menopausal women than post- menopausal women with ASCUS. Cervicitis was more common in menopausal women. Therefore, we think that in case of ASCUS in a post-menopausal woman there is no need for radical management.

  3. A novel hardware implementation for detecting respiration rate using photoplethysmography.

    Science.gov (United States)

    Prinable, Joseph; Jones, Peter; Thamrin, Cindy; McEwan, Alistair

    2017-07-01

    Asthma is a serious public health problem. Continuous monitoring of breathing may offer an alternative way to assess disease status. In this paper we present a novel hardware implementation for the capture and storage of a photoplethysmography (PPG) signal. The LED duty cycle was altered to determine the effect on respiratory rate accuracy. The oximeter was mounted to the left index finger of ten healthy volunteers. The breathing rate derived from the oximeter was validated against a nasal airflow sensor. The duty cycle of a pulse oximeter was changed between 5%, 10% and 25% at a sample rate of 500 Hz. A PPG signal and reference signal was captured for each duty cycle. The PPG signals were post processed in Matlab to derive a respiration rate using an existing Matlab toolbox. At a 25% duty cycle the RMSE was <;2 breaths per minute for the top performing algorithm. The RMSE increased to over 5 breaths per minute when the duty cycle was reduced to 5%. The power consumed by the hardware for a 5%, 10% and 25% duty cycle was 5.4 mW, 7.8 mW, and 15 mW respectively. For clinical assessment of respiratory rate, a RSME of <;2 breaths per minute is recommended. Further work is required to determine utility in asthma management. However for non-clinical applications such as fitness tracking, lower accuracy may be sufficient to allow a reduced duty cycle setting.

  4. A Third-Generation Adaptive Statistical Iterative Reconstruction Technique: Phantom Study of Image Noise, Spatial Resolution, Lesion Detectability, and Dose Reduction Potential.

    Science.gov (United States)

    Euler, André; Solomon, Justin; Marin, Daniele; Nelson, Rendon C; Samei, Ehsan

    2018-06-01

    The purpose of this study was to assess image noise, spatial resolution, lesion detectability, and the dose reduction potential of a proprietary third-generation adaptive statistical iterative reconstruction (ASIR-V) technique. A phantom representing five different body sizes (12-37 cm) and a contrast-detail phantom containing lesions of five low-contrast levels (5-20 HU) and three sizes (2-6 mm) were deployed. Both phantoms were scanned on a 256-MDCT scanner at six different radiation doses (1.25-10 mGy). Images were reconstructed with filtered back projection (FBP), ASIR-V with 50% blending with FBP (ASIR-V 50%), and ASIR-V without blending (ASIR-V 100%). In the first phantom, noise properties were assessed by noise power spectrum analysis. Spatial resolution properties were measured by use of task transfer functions for objects of different contrasts. Noise magnitude, noise texture, and resolution were compared between the three groups. In the second phantom, low-contrast detectability was assessed by nine human readers independently for each condition. The dose reduction potential of ASIR-V was estimated on the basis of a generalized linear statistical regression model. On average, image noise was reduced 37.3% with ASIR-V 50% and 71.5% with ASIR-V 100% compared with FBP. ASIR-V shifted the noise power spectrum toward lower frequencies compared with FBP. The spatial resolution of ASIR-V was equivalent or slightly superior to that of FBP, except for the low-contrast object, which had lower resolution. Lesion detection significantly increased with both ASIR-V levels (p = 0.001), with an estimated radiation dose reduction potential of 15% ± 5% (SD) for ASIR-V 50% and 31% ± 9% for ASIR-V 100%. ASIR-V reduced image noise and improved lesion detection compared with FBP and had potential for radiation dose reduction while preserving low-contrast detectability.

  5. Diagnostic performance of reduced-dose CT with a hybrid iterative reconstruction algorithm for the detection of hypervascular liver lesions: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Nakamoto, Atsushi; Tanaka, Yoshikazu; Juri, Hiroshi; Nakai, Go; Narumi, Yoshifumi [Osaka Medical College, Department of Radiology, Takatsuki, Osaka (Japan); Yoshikawa, Shushi [Osaka Medical College Hospital, Central Radiology Department, Takatsuki, Osaka (Japan)

    2017-07-15

    To investigate the diagnostic performance of reduced-dose CT with a hybrid iterative reconstruction (IR) algorithm for the detection of hypervascular liver lesions. Thirty liver phantoms with or without simulated hypervascular lesions were scanned with a 320-slice CT scanner with control-dose (40 mAs) and reduced-dose (30 and 20 mAs) settings. Control-dose images were reconstructed with filtered back projection (FBP), and reduced-dose images were reconstructed with FBP and a hybrid IR algorithm. Objective image noise and the lesion to liver contrast-to-noise ratio (CNR) were evaluated quantitatively. Images were interpreted independently by 2 blinded radiologists, and jackknife alternative free-response receiver-operating characteristic (JAFROC) analysis was performed. Hybrid IR images with reduced-dose settings (both 30 and 20 mAs) yielded significantly lower objective image noise and higher CNR than control-dose FBP images (P <.05). However, hybrid IR images with reduced-dose settings had lower JAFROC1 figure of merit than control-dose FBP images, although only the difference between 20 mAs images and control-dose FBP images was significant for both readers (P <.01). An aggressive reduction of the radiation dose would impair the detectability of hypervascular liver lesions, although objective image noise and CNR would be preserved by a hybrid IR algorithm. (orig.)

  6. Relationship between PSA kinetics and [{sup 18}F]fluorocholine PET/CT detection rates of recurrence in patients with prostate cancer after total prostatectomy

    Energy Technology Data Exchange (ETDEWEB)

    Graute, Vera; Jansen, Nathalie; Uebleis, Christopher; Cumming, Paul; Klanke, Katharina; Tiling, Reinhold; Bartenstein, Peter; Hacker, Marcus [University of Munich, Department of Nuclear Medicine, Munich (Germany); Seitz, Michael [University of Munich, Department of Urology, Munich (Germany); Hartenbach, Markus [Bundeswehrkrankenhaus Ulm, Department of Nuclear Medicine, Ulm (Germany); Scherr, Michael Karl; Thieme, Sven [University of Munich, Institute of Clinical Radiology, Munich (Germany)

    2012-02-15

    The aim of the present study was to identify prostate-specific antigen (PSA) threshold levels, as well as PSA velocity, progression rate and doubling time in relation to the detectability and localization of recurrent lesions with [{sup 18}F]fluorocholine (FC) PET/CT in patients after radical prostatectomy. The study group comprised 82 consecutive patients with biochemical relapse after radical prostatectomy. PSA levels measured at the time of imaging were correlated with the FC PET/CT detection rates in the entire group with PSA velocity (in 48 patients), with PSA doubling time (in 47 patients) and with PSA progression (in 29 patients). FC PET/CT detected recurrent lesions in 51 of the 82 patients (62%). The median PSA value was significantly higher in PET-positive than in PET-negative patients (4.3 ng/ml vs. 1.0 ng/ml; p < 0.01). The optimal PSA threshold from ROC analysis for the detection of recurrent prostate cancer lesions was 1.74 ng/ml (AUC 0.818, 82% sensitivity, 74% specificity). Significant differences between PET-positive and PET-negative patients were found for median PSA velocity (6.4 vs. 1.1 ng/ml per year; p < 0.01) and PSA progression (5.0 vs. 0.3 ng/ml per year, p < 0.01) with corresponding optimal thresholds of 1.27 ng/ml per year and 1.28 ng/ml per year, respectively. The PSA doubling time suggested a threshold of 3.2 months, but this just failed to reach statistical significance (p = 0.071). In a study cohort of patients with biochemical recurrence of prostate cancer after radical prostatectomy there emerged clear PSA thresholds for the presence of FC PET/CT-detectable lesions. (orig.)

  7. Detection of intrathoracic infectious lesions using {sup 111}In-diethylenetriamine pentaacetic bicyclic anhydride-IgG ({sup 111}In-DTPA-IgG) scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Ota, Tomohiro; Goto, Hajime; Wada, Hiroo; Yuasa, Kazumi; Iguchi, Mari; Okamura, Tatsuru; Ieki, Ryuji; Suzuki, Kenzo [Tokyo Metropolitan Komagome General Hospital (Japan)

    1998-02-01

    The utility of {sup 111}In-DTPA-IgG imaging for the detection of intrathoracic lesions was evaluated in 10 patients with the suspicion of inflammatory or infectious diseases. They were intravenously administered 40 or 80 MBq of {sup 111}In-DTPA-IgG, and scanned after 24 or 48 hours. Of these, 8 cases, consisted of 4 cases with pneumonia and 2 cases with lung abscess and one case of pulmonary tuberculosis and one of a tuberculous pleuritis, showed true positive results. Others were one false negative case of pneumonia and one true negative case of lung cancer. Overall sensitivity and specificity were 88.9% and 100%, respectively. There were no cases which showed side effects or abnormal laboratory findings caused by the radiopharmaceuticals administered. Thus, {sup 111}In-DTPA-IgG imaging is a useful tool for the detection of intrathoracic infectious lesions. (author)

  8. Detection of intrathoracic infectious lesions using 111In-diethylenetriamine pentaacetic bicyclic anhydride-IgG (111In-DTPA-IgG) scintigraphy

    International Nuclear Information System (INIS)

    Ota, Tomohiro; Goto, Hajime; Wada, Hiroo; Yuasa, Kazumi; Iguchi, Mari; Okamura, Tatsuru; Ieki, Ryuji; Suzuki, Kenzo

    1998-01-01

    The utility of 111 In-DTPA-IgG imaging for the detection of intrathoracic lesions was evaluated in 10 patients with the suspicion of inflammatory or infectious diseases. They were intravenously administered 40 or 80 MBq of 111 In-DTPA-IgG, and scanned after 24 or 48 hours. Of these, 8 cases, consisted of 4 cases with pneumonia and 2 cases with lung abscess and one case of pulmonary tuberculosis and one of a tuberculous pleuritis, showed true positive results. Others were one false negative case of pneumonia and one true negative case of lung cancer. Overall sensitivity and specificity were 88.9% and 100%, respectively. There were no cases which showed side effects or abnormal laboratory findings caused by the radiopharmaceuticals administered. Thus, 111 In-DTPA-IgG imaging is a useful tool for the detection of intrathoracic infectious lesions. (author)

  9. Local Control Rates of Metastatic Renal Cell Carcinoma (RCC) to Thoracic, Abdominal, and Soft Tissue Lesions Using Stereotactic Body Radiotherapy (SBRT)

    International Nuclear Information System (INIS)

    Altoos, Basel; Amini, Arya; Yacoub, Muthanna; Bourlon, Maria T.; Kessler, Elizabeth E.; Flaig, Thomas W.; Fisher, Christine M.; Kavanagh, Brian D.; Lam, Elaine T.; Karam, Sana D.

    2015-01-01

    We report the radiographic response rate of SBRT compared to conventional fractionated radiotherapy (CF-EBRT) for thoracic, abdominal, skin and soft tissue RCC lesions treated at our institution. Fifty three lesions where included in the study (36 SBRT, 17 CF-EBRT), treated from 2004 to 2014 at our institution. We included patients that had thoracic, skin & soft tissue (SST), and abdominal metastases of histologically confirmed RCC. The most common SBRT fractionation was 50 Gy in 5 fractions. The median time of follow-up was 16 months (range 3–97 months). Median BED was 216.67 (range 66.67–460.0) for SBRT, and 60 (range 46.67–100.83) for CF-EBRT. Median radiographic local control rates at 12, 24, and 36 months were 100, 93.41, and 93.41 % for lesions treated with SBRT versus 62.02, 35.27 and 35.27 % for those treated with CF-EBRT (p < 0.001). Predictive factors for radiographic local control under univariate analysis included BED ≥ 100 Gy (HR, 0.048; 95 % CI, 0.006–0.382; p = 0.005), dose per fraction ≥ 9 Gy (HR, 0.631; 95 % CI, 0.429–0.931; p = 0.021), and gender (HR, 0.254; 95 % CI, 0.066–0.978; p = 0.048). Under multivariate analysis, there were no significant predictors for local control. Toxicity rates were low and equivalent in both groups, with no grade 4 or 5 side effects reported. SBRT is safe and effective for the treatment of RCC metastases to thoracic, abdominal and integumentary soft tissues. Radiographic response rates were greater and more durable using SBRT compared to CF-EBRT. Further prospective trials are needed to evaluate efficacy and safety of SBRT for RCC metastases

  10. Lesion activity assessment

    DEFF Research Database (Denmark)

    Ekstrand, K R; Zero, D T; Martignon, S

    2009-01-01

    in response to cariogenic plaque as well as lesion arrest. Based on this understanding, different clinical scoring systems have been developed to assess the severity/depth and activity of lesions. A recent system has been devised by the International Caries Detection and Assessment System Committee...

  11. Effects of automatic tube potential selection on radiation dose index, image quality, and lesion detectability in pediatric abdominopelvic CT and CTA: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Brinkley, Michael F.; Choudhury, Kingshuk Roy; Frush, Donald P. [Duke University School of Medicine, Department of Radiology, DUMC Box 3808, Durham, NC (United States); Ramirez-Giraldo, Juan C. [Siemens Healthcare, Malvern (United States); Samei, Ehsan; Wilson, Joshua M.; Christianson, Olav I. [Duke University School of Medicine, Clinical Imaging Physics Group, Department of Radiology, Durham, NC (United States); Frush, Daniel J. [Duke University School of Medicine, Medical Physics, Durham, NC (United States)

    2016-01-15

    To assess the effect of automatic tube potential selection (ATPS) on radiation dose, image quality, and lesion detectability in paediatric abdominopelvic CT and CT angiography (CTA). A paediatric modular phantom with contrast inserts was examined with routine pitch (1.4) and high pitch (3.0) using a standard abdominopelvic protocol with fixed 120 kVp, and ATPS with variable kVp in non-contrast, contrast-enhanced, and CTA mode. The volume CT dose index (CTDI{sub vol}), contrast-to-noise ratio (CNR) and lesion detectability index (d') were compared between the standard protocol and ATPS examinations. CTDI{sub vol} was reduced in all routine pitch ATPS examinations, with dose reductions of 27-52 % in CTA mode (P < 0.0001), 15-33 % in contrast-enhanced mode (P = 0.0003) and 8-14 % in non-contrast mode (P = 0.03). Iodine and soft tissue insert CNR and d' were improved or maintained in all ATPS examinations. kVp and dose were reduced in 25 % of high pitch ATPS examinations and in none of the full phantom examinations obtained after a single full phantom localizer. ATPS reduces radiation dose while maintaining image quality and lesion detectability in routine pitch paediatric abdominopelvic CT and CTA, but technical factors such as pitch and imaging range must be considered to optimize ATPS benefits. (orig.)

  12. How often do surgeons intervene on shoulder labral lesions detected at MR examination? A retrospective review of MR examinations correlated with arthroscopy

    Science.gov (United States)

    2014-01-01

    Objective: We report the prevalence of surgical intervention on shoulder labral lesions detected at MR examinations and how surgeons describe labral tears seen at MR examinations in their arthroscopy reports. Methods: A retrospective review of 100 consecutive patients aged 50 years or younger who had shoulder labral tears on MR and went on to have surgery performed. It was determined whether surgical intervention was performed on the MR lesions. Results: Of these 100 patients, 72 had superior labral anterior to posterior (SLAP) tears, 38 had posterior labral tears and 28 had anterior labral tears on MR examination. All 100 patients went on to arthroscopy. All lesions described on MRI were described on arthroscopy. Of the 72 SLAP tears, 64 were described as fraying on arthroscopy with 51 debrided. The remaining eight SLAP tears were tacked surgically. Of the 38 posterior labral tears, 36 were described as fraying on arthroscopy with 29 debrided and 2 had surgical tacking performed. Of the 28 anterior labral tears described on MR examination, 26 had surgical tacking performed and 2 were debrided. There were four SLAP tears, two anterior labral tears and three posterior labral tears seen on arthroscopy but not seen on MR examination. Conclusion: In this series, a high percentage of SLAP tears and posterior labral tears described on MR examination did not have surgical tacking. Most anterior labral tears had surgical tacking. Based on the above, our surgeons request we describe superior and posterior labral lesions as fraying and/or tearing, unless we can see a displaced tear. Most anterior labral lesions are treated with surgical tacking. Advances in knowledge: MRI allows for sensitive detection of labral tears. The tears often are not clinically significant. PMID:24712320

  13. Development of standardized image interpretation for 68Ga-PSMA PET/CT to detect prostate cancer recurrent lesions

    Energy Technology Data Exchange (ETDEWEB)

    Fanti, Stefano; Ceci, Francesco; Castellucci, Paolo [University of Bologna, S. Orsola Hospital Bologna, Nuclear Medicine Unit, Bologna (Italy); Minozzi, Silvia [Lazio Regional Health Service, Department of Epidemiology, Rome (Italy); Morigi, Joshua James; Emmett, Louise [St. Vincent' s Public Hospital, Department of Diagnostic Imaging, Sydney (Australia); Giesel, Frederik; Haberkorn, Uwe [University Hospital Heidelberg, Department of Nuclear Medicine, Heidelberg (Germany); Uprimny, Christian; Virgolini, Irene [Medical University Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Hofman, Michael S.; Hicks, Rodney J. [Peter MacCallum Cancer Centre, Centre for Molecular Imaging, Department of Cancer Imaging, Melbourne (Australia); Eiber, Matthias; Schwaiger, Markus [Technical University Munich, Department of Nuclear Medicine, Munich (Germany); Schwarzenbock, Sarah; Krause, Bernd J. [University Medical Centre, Department of Nuclear Medicine, Rostock (Germany); Bellisario, Cristina [University Hospital ' ' Citta della Salute e della Scienza di Torino' ' , Department of Cancer Screening, Centre for Epidemiology and Prevention in Oncology (CPO), Turin (Italy); Chauvie, Stephane; Bergesio, Fabrizio [Santa Croce e Carle Hospital, Medical Physics Division, Cuneo (Italy); Chiti, Arturo [Humanitas Clinical and Research Hospital, Nuclear Medicine, Humanitas Cancer Center, Rozzano, MI (Italy)

    2017-09-15

    After primary treatment, biochemical relapse (BCR) occurs in a substantial number of patients with prostate cancer (PCa). PET/CT imaging with prostate-specific membrane antigen based tracers (68Ga-PSMA) has shown promising results for BCR patients. However, a standardized image interpretation methodology has yet to be properly agreed. The aim of this study, which was promoted and funded by European Association of Nuclear Medicine (EANM), is to define standardized image interpretation criteria for 68Ga-PSMA PET/CT to detect recurrent PCa lesions in patients treated with primary curative intent therapy (radical prostatectomy or radiotherapy) who presented a biochemical recurrence. In the first phase inter-rater agreement between seven readers from seven international centers was calculated on the reading of 68Ga-PSMA PET/CT images of 49 patients with BCR. Each reader evaluated findings in five different sites of recurrence (local, loco-regional lymph nodes, distant lymph nodes, bone, and other). In the second phase the re-analysis was limited to cases with poor, slight, fair, or moderate agreement [Krippendorff's (K) alpha<0.61]. Finally, on the basis of the consensus readings, we sought to define a list of revised consensus criteria for 68Ga-PSMA PET/CT interpretation. Between-reader agreement for the presence of anomalous findings in any of the five sites was only moderate (K's alpha: 0.47). The agreement improved and became substantial when readers had to judge whether the anomalous findings were suggestive for a pathologic, uncertain, or non-pathologic image (K's alpha: 0.64). K's alpha calculations for each of the five sites of recurrence were also performed and evaluated. First Delphi round was thus conducted. A more detailed definition of the criteria was proposed by the project coordinator, which was then discussed and finally agreed by the seven readers. After the second Delphi round only four cases of disagreement still remained. These

  14. Silent hepatic lesions detected with computed tomography in aplastic anemia patients administered androgens for a long period

    International Nuclear Information System (INIS)

    Yamagishi, Morihisa; Hiraoka, Atsunobu; Uchino, Haruto.

    1982-01-01

    Macroscopic liver lesions were investigated with the use of computed tomography (CT) and radionuclide imaging (RN) in 15 aplastic anemia patients who were administered anabolic steroids for over one year and who showed no apparent physical and biochemical sign of liver tumor. In 3 patients, CT scans showed radiolucent areas in the liver. Contrast enhancements revealed these lesions to be well vascularized, suggesting they were not cysts but probably tumors. RN imaging could not demonstrate any definite space occupying lesions. Total dose of AS administered to each of the three patients exceeded 30,000 mg. It was felt that attention should be paid to the possible development of hepatic tumor when the dose of AS administered exceeds 30,000 mg. (author)

  15. Silent hepatic lesions detected with computed tomography in aplastic anemia patients administered androgens for a long period

    Energy Technology Data Exchange (ETDEWEB)

    Yamagishi, Morihisa (Shiga Univ., Otsu (Japan)); Hiraoka, Atsumobu; Uchino, Haruto

    1982-07-01

    Macroscopic liver lesions were investigated with the use of computed tomography (CT) and radionuclide imaging (RN) in 15 aplastic anemia patients who were administered anabolic steroids for over one year and who showed no apparent physical and biochemical sign of liver tumor. In 3 patients, CT scans showed radiolucent areas in the liver. Contrast enhancements revealed these lesions to be well vascularized, suggesting they were not cysts but probably tumors. RN imaging could not demonstrate any definite space occupying lesions. Total dose of AS administered to each of the three patients exceeded 30,000 mg. It was felt that attention should be paid to the possible development of hepatic tumor when the dose of AS administered exceeds 30,000 mg.

  16. Comparison between gadolinium-enhanced 2D T1-weighted gradient-echo and spin-echo sequences in the detection of active multiple sclerosis lesions on 3.0T MRI

    Energy Technology Data Exchange (ETDEWEB)

    Aymerich, F.X. [Hospital Universitari Vall d' Hebron, Universitat Autonoma de Barcelona, MR Unit. Department of Radiology (IDI), Barcelona (Spain); Universitat Politecnica de Catalunya - Barcelona Tech (UPC), Department of Automatic Control (ESAII), Barcelona (Spain); Auger, C.; Alcaide-Leon, P.; Pareto, D.; Huerga, E.; Corral, J.F.; Mitjana, R.; Rovira, A. [Hospital Universitari Vall d' Hebron, Universitat Autonoma de Barcelona, MR Unit. Department of Radiology (IDI), Barcelona (Spain); Sastre-Garriga, J.; Montalban, X. [Hospital Universitari Vall d' Hebron, Universitat Autonoma de Barcelona, Centre d' Esclerosi Multiple de Catalunya (Cemcat), Department of Neurology/Neuroimmunology, Barcelona (Spain)

    2017-04-15

    To compare the sensitivity of enhancing multiple sclerosis (MS) lesions in gadolinium-enhanced 2D T1-weighted gradient-echo (GRE) and spin-echo (SE) sequences, and to assess the influence of visual conspicuity and laterality on detection of these lesions. One hundred MS patients underwent 3.0T brain MRI including gadolinium-enhanced 2D T1-weighted GRE and SE sequences. The two sets of contrast-enhanced scans were evaluated in random fashion by three experienced readers. Lesion conspicuity was assessed by the image contrast ratio (CR) and contrast-to-noise ratio (CNR). The intracranial region was divided into four quadrants and the impact of lesion location on detection was assessed in each slice. Six hundred and seven gadolinium-enhancing MS lesions were identified. GRE images were more sensitive for lesion detection (0.828) than SE images (0.767). Lesions showed a higher CR in SE than in GRE images, whereas the CNR was higher in GRE than SE. Most misclassifications occurred in the right posterior quadrant. The gadolinium-enhanced 2D T1-weighted GRE sequence at 3.0T MRI enables detection of enhancing MS lesions with higher sensitivity and better lesion conspicuity than 2D T1-weighted SE. Hence, we propose the use of gadolinium-enhanced GRE sequences rather than SE sequences for routine scanning of MS patients at 3.0T. (orig.)