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991.
Imaging plays a major role in the identification, grading, and treatment of cerebral arteriovenous malformations and cerebral dural arteriovenous fistulas. Digital subtraction angiography is the gold standard in the diagnosis and characterization of these vascular malformations, but advances in both magnetic resonance imaging and computed tomography, including advanced imaging techniques, have provided new tools for further characterizing these lesions as well as the surrounding brain structures that may be affected. This article discusses the role of conventional as well as advanced imaging modalities that are providing novel ways to characterize these vascular malformations. 相似文献
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Posterior cruciate ligament (PCL) injuries from tibial avulsions are rare in the paediatric setting. One would need a high index of suspicion as clinical examination may be difficult, especially in the early period. Magnetic resonance imaging is an excellent diagnostic modality for this condition and other associated injuries within the knee. We report a rare case in which the patient had a PCL avulsion off the tibial insertion site with an associated posterior horn medial meniscal tear off the posterior capsule. He was treated through open reduction and internal fixation of the avulsed fragment with suture repair of the meniscal tear. We emphasize the importance of diagnosing and managing associated intra-articular injuries when dealing with the rare condition of PCL tibial avulsion in the paediatric setting. 相似文献
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Abdul Razik Chandan J Das Raju Sharma Sundeep Malla Sanjay Sharma Amlesh Seth Deep Narayan Srivastava 《The British journal of radiology》2021,94(1122)
Objective:To explore the utility of first-order MRI-texture analysis (TA) parameters in predicting histologic grade and muscle invasion in urinary bladder cancer (UBC).Methods:After ethical clearance, 40 patients with UBC, who were imaged on a 3.0-Tesla scanner, were retrospectively included. Using the TexRADTM platform, two readers placed freehand ROI on the sections demonstrating the largest dimension of the tumor, evaluating only one tumor per patient. Interobserver reproducibility was assessed using the intraclass correlation coefficient (ICC). Mann–Whitney U test and ROC curve analysis were used to identify statistical significance and select parameters with high class separation capacity (AUC >0.8), respectively. Pearson’s test was used to identify redundancy in the results.Results:All texture parameters showed excellent ICC. The best parameters in differentiating high and low-grade tumors were mean/ mean of positive pixels (MPP) at SSF 0 (AUC: 0.897) and kurtosis at SSF 5 (AUC: 0.828) on the ADC images. In differentiating muscle invasive from non-muscle invasive tumors, mean/ MPP at SSF 0 on the ADC images showed AUC >0.8; however, this finding resulted from the confounding effect of high-grade histology on the ADC values of muscle invasive tumors.Conclusion:MRI-TA generated few parameters which were reproducible and useful in predicting histologic grade. No independent parameters predicted muscle invasion.Advances in knowledge:There is lacuna in the literature concerning the role of MRI-TA in the prediction of histologic grade and muscle invasion in UBC. Our study generated a few first-order parameters which were useful in predicting high-grade histology. 相似文献
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Brent D. Parsons Shilpa Gandhi Elyse L. Aurbach Nina Williams Micah Williams Adel Wassef David M. Eagleman 《Neuropsychologia》2013,51(2):372-376
Research in schizophrenia has tended to emphasize deficits in higher cognitive abilities, such as attention, memory, and executive function. Here we provide evidence for dysfunction at a more fundamental level of perceptual processing, temporal integration. On a measure of flicker fusion, patients with schizophrenia exhibited significantly lower thresholds than age and education matched healthy controls. We reasoned that this finding could result from a longer window of temporal integration or could reflect diminished repetition suppression: if every frame of the repeating stimulus were represented as novel, its perceived duration would be accordingly longer. To tease apart these non-exclusive hypotheses, we asked patients to report the number of stimuli perceived on the screen at once (numerosity) as they watched rapidly flashing stimuli that were either repeated or novel. Patients reported significantly higher numerosity than controls in all conditions, again indicating a longer window of temporal integration in schizophrenia. Further, patients showed the largest difference from controls in the repeated condition, suggesting a possible effect of weaker repetition suppression. Finally, we establish that our findings generalize to several different classes of stimuli (letters, pictures, faces, words, and pseudo-words), demonstrating a non-specific effect of a lengthened window of integration. We conclude that the visual system in schizophrenics integrates input over longer periods of time, and that repetition suppression may also be deficient. We suggest that these abnormalities in the processing of temporal information may underlie higher-level deficits in schizophrenia and account for the disturbed sense of continuity and fragmentation of events in time reported by patients. 相似文献
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Ajeet Kumar Gandhi Soumyajit Roy Alok Thakar Atul Sharma Bidhu Kalyan Mohanti 《Indian Journal of Palliative Care》2014,20(3):189-193