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Sfax, Tunisia

Masmoudi A.D.,University of Sfax | Ben Ayed N.G.,University of Sfax | Masmoudi D.S.,University of Sfax | Abid R.,Radiology Center
Eurasip Journal on Image and Video Processing | Year: 2013

Mammogram tissue density has been found to be a strong indicator for breast cancer risk. Efforts in computer vision of breast parenchymal pattern have been made in order to improve the diagnostic accuracy by radiologists. Motivated by recent results in mammogram tissue density classification, a novel methodology for automatic American College of Radiology Breast Imaging Reporting and Data System classification using local binary pattern variance descriptor is presented in this article. The proposed approach characterizes the local density in different types of breast tissue patterns information into the LBP histogram. The performance of macro-calcification detection methods is developed using FARABI database. Performance results are given in terms of receiver operating characteristic. The area under curve of the corresponding approach has been found to be 79%. © 2013 Damak Masmoudi et al.; licensee Springer. Source

Xylinas E.,Pitie Salpetriere | Xylinas E.,University Pierre and Marie Curie | Yates D.R.,Pitie Salpetriere | Yates D.R.,University Pierre and Marie Curie | And 12 more authors.
World Journal of Urology | Year: 2013

Objectives: To assess the value of dynamic contrast-enhanced magnetic resonance imaging (MRI) for the prediction of extracapsular extension (ECE) in patients with clinical T3 (cT3) prostate cancer (PCa) compared to digital rectal examination (DRE). Materials and methods: A retrospective review of data for patients treated by radical prostatectomy for cT3 PCa was performed. Patients who underwent MRI in the pre-operative work-up were included. The likelihoods of extracapsular extension (T3a) and seminal vesicle invasion (T3b) were scored on the basis of MR images. For data analysis, receiver operating characteristic (ROC) curves were generated. Results: Overall, 70 consecutive patients were included. Mean age was 63.8 (range 45-75) years, and the mean PSA level was 11.3 (range 2.9-26) ng/ml. Pathological analysis of the prostatic specimens confirmed 81.4% (n = 57) had pT3 disease. According to MRI, 57 (81.4%) patients were predicted correctly to have T3 disease. The overstaging (actual pT2) by either DRE or MRI or both was 18.6, 7 or 7%, respectively. The sensitivity, specificity and positive (PPV) and negative predictive values (NPV) of MRI were 94.7, 69, 93 and 75%. The kappa index of concordance between pre-operative MRI stage and pathological stage was 0.68 (P < 0.00001). The performance of MRI for T3 staging was AUC 0.87 (95% CI, 0.77-0.97). Conclusions: Pre-prostatectomy MRI adds significant incremental value to the assessment of patients with cT3 disease. Its ability to accurately predict and characterize pathological T3 status and its superiority to standard clinical variables (e.g. DRE) confirm its usefulness in pre-operative work-up. © 2011 Springer-Verlag. Source

Yuan H.,Radiology Center | Qi J.,Tianjin Medical University
Chinese Journal of Medical Imaging Technology | Year: 2011

Objective: To assess the correlation between abnormal metabolic changes and Wisconsin card sorted test(WCST) in patients with depression using magnetic resonance spectroscopy (MRS). Methods: Twelve healthy volunteers (group 1), 12 first-episode patients (group 2) and 10 recurrent patients (group 3) underwent WCST before MR examination. Localized magnetic resonance spectra were acquired in bilateral prefrontal lobe and cingulated cortex with single voxel 1-hydrogen MRS ( 1H-MRS). The ratio of all metabolte including N-acetyl-asparta (NAA), choline (Cho), glutamate and glutamine (Glx) were recorded, using creatine (Cr) as reference. Results: Compared to group 1, Glx/Cr decreased and mIns/Cr increased in both bilateral prefrontal lobes in group 3, while Glx/Cr decreased in bilateral prefrontal lobes and mIns/Cr increased in right side in group 2. Response administered (RA), perseverative errors (PE) and non perseverative errors (NPE) were higher in group 2 and 3 in WCST. Glx/Cr of right prefrontal lobe correlated negatively with PE significantly in group 2, Glx/Cr of bilateral prefrontal lobes all correlated negatively with PE significantly in group 3. Conclusion: The depressive patients have abnormal metabolic changes in bilateral prefrontal lobes as well as cognitive impairment, and glutamatergic system dysregulation may be the pathophysiologic basis of cognitive impairement in patients with depression. Source

Guglielmo F.F.,Thomas Jefferson University | Mitchell D.G.,Thomas Jefferson University | O'Kane P.L.,Thomas Jefferson University | Deshmukh S.P.,Thomas Jefferson University | And 5 more authors.
Abdominal Imaging | Year: 2015

Purpose: The purpose of this study was to evaluate whether affected bowel in Crohn’s disease patients can be identified by observing decreased peristalsis (frozen bowel sign) using cine balanced steady-state free precession (cine BSSFP) images. Materials and methods: 5 radiologists independently reviewed cine BSSFP sequences from randomized MR Enterography (MRE) exams for 30 normal and 30 Crohn’s disease patients, graded overall small bowel peristalsis from slowest to fastest, and graded peristalsis for the most abnormal small bowel segment. Sensitivity and specificity of the frozen bowel sign for diagnosing Crohn’s disease were calculated. T tests of the peristalsis difference between abnormal segments and overall small bowel were conducted. Results: For 5 readers, the sensitivity and specificity of cine BSSFP of the frozen bowel sign for diagnosing Crohn’s disease ranged from 70% to 100% and 87% to 100%, respectively. There were significant differences in peristalsis between abnormal small bowel segments and the overall small bowel for Crohn’s patients, but not in the overall small bowel between normal-MRE patients and Crohn’s disease patients. Conclusion: Abnormal Crohn’s small bowel segments have significantly decreased peristalsis compared to normal small bowel, which can be identified using cine BSSFP sequences as the frozen bowel sign. © 2014, Springer Science+Business Media New York. Source

Sillat T.,University of Helsinki | Sillat T.,Radiology Center | Barreto G.,University of Helsinki | Clarijs P.,University of Helsinki | And 9 more authors.
Acta Orthopaedica | Year: 2013

Background and purpose Degenerating cartilage releases potential danger signals that react with Toll-like receptor (TLR) type danger receptors. We investigated the presence and regulation of TLR1, TLR2, and TLR9 in human chondrocytes. Methods We studied TLR1, TLR2, TLR4, and TLR9 mRNA (qRT-PCR) and receptor proteins (by immunostaining) in primary mature healthy chondrocytes, developing chondrocytes, and degenerated chondrocytes in osteoarthritis (OA) tissue sections of different OARSI grades. Effects of a danger signal and of a pro-inflammatory cytokine on TLRs were also studied. Results In primary 2D-chondrocytes, TLR1 and TLR2 were strongly expressed. Stimulation of 2D and 3D chondrocytes with a TLR1/2-specific danger signal increased expression of TLR1 mRNA 1.3- to 1.8-fold, TLR2 mRNA 2.6- to 2.8-fold, and TNF-α mRNA 4.5- to 9-fold. On the other hand, TNF-α increased TLR1 mRNA] expression 16-fold, TLR2 mRNA expression 143- to 201-fold, and TNF-α mRNA expression 131- to 265-fold. TLR4 and TLR9 mRNA expression was not upregulated. There was a correlation between worsening of OA and increased TLR immunostaining in the superficial and middle cartilage zones, while chondrocytes assumed a CD166 × progenitor phenotype. Correspondingly, TLR expression was high soon after differentiation of mesenchymal stem cells to chondrocytes. With maturation, it declined (TLR2, TLR9). Interpretation Mature chondrocytes express TLR1 and TLR2 and may react to cartilage matrix/chondrocyte-derived danger signals or degradation products. This leads to synthesis of pro-inflammatory cytokines, which stimulate further TLR and cytokine expression, establishing a vicious circle. This suggests that OA can act as an autoinflammatory disease and links the old mechanical wear-and-tear concept with modern biochemical views of OA. These findings suggest that the chondrocyte itself is the earliest and most important inflammatory cell in OA. © Nordic Orthopaedic Federation. Source

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