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ObjectiveTo study the potential of using temporal clustering analysis(TCA)technique in localizing an epileptogenic zone.MethodsTwelve patients with epilepsy were examined using resting functional MRI(fMRI). The patients had detectable focal lesions on cranial MRI.TCA was performed to analyze resting fMRI data in order to identify the timing of interictal epileptiform discharges (IEDs).Standard event-related fMRI analysis in SPM99 was used to generate maps of the activation induced by epileptic brain activities.Comparisons were made between TCA Resultsand SPM motion trochoid.ResultsEight of the twelve subiects showed activations in the brain regions that were consistent with those lesions determined on anatomic MRI.The remaining four subiects showed no clear activation in the areas of detectable lesions. In addition, correlation was found between TCA Resultsand motion trochoids.ConclusionsTemporal cluster analysis,an exploratory data-driven technique,may provide the timing information about interictal epileptiforill discharges.However,the Resultsfrom this novel fMRI analytical technique need to be interpreted with caution as it is vulnerable to motion artifact.
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Objective To analyze the radiolngical findings of mediastinal ganglioneuroma and to improve its diagnostic accuracy. Methods Imaging data of 8 cases of pathologically proven mediastinal ganglioueuroma were restrospectively analyzed. Results These tumors could occur in the anterior mediastinum, middle mediastinum or posterior mediastinum, with a preference for the posterior mediastinum (6/8). No specific clinical symptoms and signs were observed. Well-defined enlargrment of mediastinum with homogeneous density was shown on plain X-Ray. CT scanning was performed in 7 cases, including non-contrast scan alone (n = 3 ), both non-coutrast and contrast-enhanced scans ( n = 4). Round or oval shaped, well circumscribed, homogeneous or slightly heterogeneous, hypadense masses were demonstrated on non-contrast scan. Spotty calification could be found in a few cases. Homogeneous or slightly heterogeneous enhancement was seen following the intravenous injection of contrast material. Large tumors showed a tendency of wedging into the space between adjacent organs and structures, and encasing the nearby large vessels. MR without contrast was performed in 1 case. T1 WI showed isointensity to adjacent muscle, T2WI showed homogeneous hyperintensity. Multi-planar reconstruction provided more information concerning the relationship of the mass lesions with neighboring structures. Conclusion Mediastinal ganglioneuromas have some specific characterstics on imaging studies, which could assist in pre-operative diagnosis and surgical planning.
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Dynamic contrasted-enhanced perfusion MR imaging can provide noninvasive and physical maps of cerebral microcirculation. The tumor vascularities are assessed by calculating cerebral blood volumes of the normal cerebral tissue and tumor tissue from imaging signal intensities. This technique is helpful to better evaluate the histopathological grade of gliomas, determine the biopsy site for tumors. And it is very useful for the preoperative diagnosis of gliomas, solitary metastases, cerebral lymphomas, as well as differentiating tumor recurrence after surgical resection and radiotherapy from radiation necrosis. But there are some limitations in evaluating extraaxial tumors and cerebral tumors with severe breakdown of blood-brain barrier.
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Objective Different grades of glioma lead to different clinical course,treatments and prognosis,thus it is important to predict histological grades of glioma preoperatively.18F-FDG PET/CT imaging and MR perfusion imaging is considered a promising method to evaluate glioma,and the present study was to evaluated the contribution of 18F-FDG PET/CT imaging and MR perfusion imaging in grading intracranial glioma.Methods Eighteen consecutive patients with suspected primary brain glioma underwent 18F-FDG PET/CT scanning and MR perfusion scanning in our hospital.To evaluate the relative sensitivity among standardized uptake value (SUV),L/W,and rCBV,the PET/CT imaging were analyzed,and the SUV and Lesion-to-white matter ratio (L/W) were calculated.The rCBV ratios of lesions were calculated relative to the region of interest (ROI) values in contra lateral normal white matter.Results Eighteen brain gliomas were confirmed by pathologic diagnosis,including 7 WHOⅡ tumors,6 WHOⅢ tumors,and 5 WHOⅣ tumors.SUV and rCBV could not differentiate between WHOⅡ tumor and WHOⅢ tumor,however significant difference could be found among the three using L/W.Conclusion 18F-FDG PET/CT imaging and MR perfusion imaging could offer more diagnostic information than conventional MRI.All of the three semiquantitative data offer some contribution in grading intracranial gliomas,and L/W might be the best one.
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Atypical teratoid/rhabdoid tumor of the central nervous system has aggressive growth with high potential CSF dissemination and frequently affects very young children.The tumor contains rhabdoid cells and primitive neuroectodermal,malignant mesenchymal and epithelial elements.Immunohistochemistry is helpful in differentiating atypical teratoid/rhabdoid tumor from primitive neuroectodermal tumor/medulloblastoma.Atypical teratoid/rhabdoid tumor is cytogenetically characterized by monosomy 22 or deletion of chromosome band 22q11.2.Intensified therapy combined with surgical resection has been suggested for its treatment.Due to the secondary cystic/necrotic changes and hemorrhage,the imaging features of the tumor are variable.
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Objective To study the anatomy of the thoracic outlet and inlet,and to evaluate the CT diagnosis and differential diagnosis on abnormal conditions.Methods CT images of 117 pathologically and clinically proved cases in the zones were analyzed retrospectively.Control group contained 50 normal volunteers who were divided into 5 anatomic regions: region 1 (thyroid zone),region 2 (interior thyroid),region 3 (lateral thyroid),region 4 (posterior thyroid),and region 5 (anterior thyroid).Results Of the 117 cases,there were 11 cases (9.40%) in region 1,8 cases (6.84%) in region 2,72 cases (61.54%) in region 3,1 case (0.85%) in region 4,3 cases (2.56%) in region 5,15 cases (12.8%) in transregions (region 1,3,5),and 7 cases (5.98%) in transregions (region 1,2,3).The disorders were mainly distributed in region 3,in which lymphatic node abnormalities were the most common (55 cases).The 32 cases of abnormal thyroid gland were mainly located in region 1 and involved with other regions.Conclusion The 5 regions divided on CT anatomy of the thoracic outlet and inlet are very useful for the localization and definition in the diagnosis,which have important clinical value.