Journal of neuroimaging : official journal of the American Society of Neuroimaging
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The events leading up to the development of new multiple sclerosis (MS) lesions on conventional imaging are unknown. The purpose of this study is to use diffusion tensor imaging (DTI) to investigate prelesional changes in MS to better understand the pathological changes that lead to lesion development. ⋯ A significant change in diffusion measures can be seen prior to gadolinium enhancement. Changes in TD drove changes in FA and MD, providing evidence for impaired myelin integrity prior to gadolinium enhancement. DTI may be a sensitive measure for early detection of inflammatory disease activity in MS.
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Spinal cord (SC) pathology is common in multiple sclerosis (MS), and measures of SC-atrophy are increasingly utilized. Normalization reduces biological variation of structural measurements unrelated to disease, but optimal parameters for SC volume (SCV)-normalization remain unclear. Using a variety of normalization factors and clinical measures, we assessed the effect of SCV normalization on detecting group differences and clarifying clinical-radiological correlations in MS. ⋯ SCV-normalization by length improves the ability to detect group differences, strengthens clinical-radiological correlations, and is particularly relevant in settings of subtle disease-related SC-atrophy in MS. SCV-normalization by length may enhance the clinical utility of measures of SC-atrophy.
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Extraventricular neurocytoma and ganglioneurocytoma are rare intra-axial brain neoplasms that are now recognized as distinct entities in the 2007 WHO classification of brain tumors. We describe the conventional MR imaging, perfusion MRI, proton MR spectroscopy (1H MRS), histopathology, immunohistochemistry, and chromosomal analysis in two cases of these tumors, with some features which have not been previously well described. ⋯ Both tumor types showed an elevated Cho/Cr ratio, but extraventricular ganglioneurocytoma showed a preserved NAA/Cr ratio. These tumors should be considered in the differential diagnosis of intra-axial brain tumors.
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Vasospasm has been considered the most severe acute complication after subarachnoid hemorrhage (SAH). MRA is not considered ideal for detecting cerebral vasospasm because of background including the hemorrhage. The aim of this study is to evaluate the efficacy of Subtraction MRA (SMRA) by comparing it to that of conventional MRA (CMRA) for diagnosis of cerebral vasospasm. ⋯ Diagnosis of cerebral vasospasm is more accurate by SMRA than by CMRA. The advantages are its noninvasive nature and its ability to detect cerebral vasospasm.
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An organized hematoma shows a heterogeneous signal intensity on T1-and T2-weighted images on MR imaging, reflecting variable stages of hemorrhage. Although rather nonspecific, precontrast CT images of an organized hematoma demonstrate inhomogeneous hyperdense mass with or without calcification. ⋯ Computed tomography and magnetic resonance imaging findings of the organized hematoma are shown and discussed. We believe that recognition of the characteristic imaging findings of the organized hematoma as well as consideration of the history of surgery or anticoagulation treatment assists in its correct diagnosis enabling an inappropriate surgery to be avoided.