Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Diffusion tensor imaging (DTI) quantifies the motion of water within brain tissue. Inflammation leads to tissue disruption, resulting in increased diffusivity and decreased directionality. We aimed to quantify the damage within tumefactive giant brain lesions (TGL) in multiple sclerosis (MS) using MRI and DTI methodology. ⋯ Within the spectrum of acute MS lesions, TGL present DTI metrics of an intense acute inflammatory process. Analysis of TGL progression proposes that DTI metrics sensitively detects micro-structural changes in TGL from acute inflammation towards lesion recovery and reorganization.
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Case Reports
Structural and metabolic features of two different variants of multiple sclerosis: a PET/MRI study.
Multimodality imaging such as proton magnetic resonance spectroscopy (MRS) and positron emission tomography (PET) have provided information specific to the underlying mechanisms of many brain diseases, including multiple sclerosis (MS). ⋯ Our findings illustrate that metabolic features may differ between variants of MS possibly signifying different disease activity.
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Collateral flow augmentation using partial aortic occlusion may improve cerebral perfusion in acute stroke. We assessed the effect of partial aortic occlusion on arterial flow velocities of acute stroke patients. ⋯ TCD monitoring of patients treated with IABI may help in predicting outcome in this novel device.
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Comparative Study
Voxel-based statistical analysis of fractional anisotropy and mean diffusivity in patients with unilateral temporal lobe epilepsy of unknown cause.
To determine regional alterations of fractional anisotropy (FA) and mean diffusivity (MD) in patients with magnetic resonance imaging (MRI)-negative temporal lobe epilepsy with unknown cause (TLEu) using diffusion tensor imaging (DTI) and voxel-based statistics (VBS). ⋯ Water diffusion abnormalities are widespread and bilaterally distributed in patients with unilateral TLEu, which are beyond the resolution of conventional MRI. FA alterations are more widespread relative to MD alterations. This is the first study to show evidence of interrelated microscopic (ie, FA increase) and macroscopic (ie, atrophy) alterations of the putamen in patients with TLEu.
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Case Reports
Cortical activation changes in patients suffering from post-stroke arm spasticity and treated with botulinum toxin a.
Botulinum toxin (BoNT) treatment relieves focal arm spasticity after stroke, likely acting at several hierarchical levels of the motor system. The central correlate of BoNT-induced spasticity relief may be detected using repeated functional MRI (fMRI) during motor task. ⋯ Relief of post-stroke arm spasticity may be associated with changes at several hierarchical levels of the cortical sensorimotor system, including the prefrontal cortex.