Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Studies on Whites and Asians have shown contradictory results on the association between an incomplete circle of Willis (CoW) and white matter disease (WMD). We evaluated such relationship in Ecuadorian Mestizos. ⋯ In the Ecuadorian Mestizo population, WMD occurrence and severity do not seem to be related to incompleteness of the CoW.
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Studies of brain tumors have identified altered tissue metabolism and water diffusion in MRI normal appearing tissue regions. In this retrospective study the relationship of these imaging measures with tumor grade in gliomas was investigated. ⋯ This study supports previous observations of altered tissue metabolism and water diffusion in normal-appearing white matter while additionally finding differences of metabolite values in gray matter and an association with tumor grade.
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Real-time MR imaging might exert a profound influence on neuroscience in the future by enabling the direct visualization of neuronal interactions. At this time, however, all practical embodiments of MRI require at least some degree of gradient encoding, and this in turn sets a lower limit of about 100 ms for volume acquisition. ⋯ This permits a rate of signal acquisition that is increased hundreds of times compared with existing techniques, with full 3-D imaging in as little as one millisecond. The proposed detector now resembles a holographic recording.
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Randomized Controlled Trial Multicenter Study
Derivation and evaluation of thresholds for core and tissue at risk of infarction using CT perfusion.
Computed tomography perfusion provides information on tissue viability according to proposed thresholds. We evaluated thresholds for ischemic core and tissue at risk and subsequently tested their accuracy in independent datasets. ⋯ Time-based perfusion thresholds perform well as predictors of tissue at risk of infarction with DT the best predictor. Relative CBF was the best predictor of ischemic core. Evaluation in larger populations is needed to confirm the performance of tissue viability thresholds.
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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.