Journal of neuroimaging : official journal of the American Society of Neuroimaging
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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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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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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.
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Observational Study
Black blood MRI in suspected large artery primary angiitis of the central nervous system.
Single case reports suggest that black blood MRI (T1-weighted fat and blood suppressed sequences with and without contrast injection; BB-MRI) may visualize intracranial vessel wall contrast enhancement (CE) in primary angiitis of the central nervous system (PACNS). In this single-center observational pilot study we prospectively investigated the value of BB-MRI in the diagnosis of large artery PACNS. ⋯ Our pilot study demonstrates that vessel wall CE is a frequent finding in PACNS and its mimics. Larger trials will be necessary to evaluate the utility of BB-MRI in the diagnostic workup of PACNS.
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Comparative Study
Hippocampal magnetization transfer ratio at 3T: validation of automated postprocessing and comparison of quantification metrics.
To investigate the reliability of a novel magnetization transfer ratio (MTR) postprocessing technique for the hippocampus using histogram analysis, and compare results to more established volumetric measurements. This study is conducted in healthy volunteers as a precursor to future applications regarding progressive neurologic diseases, such as Alzheimer's disease. ⋯ Excellent scan-rescan reproducibility (ICC > .9, COV < 10%) was observed for specific MTR histogram metrics and the mean MTR approach. These results are comparable to the volumetric approach. Future studies can examine the possibility that MTR changes precede morphological changes as this study suggests that both MTR and volumetric measurements of the hippocampus can be used as reliable imaging tools.