Journal of neuroimaging : official journal of the American Society of Neuroimaging
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To evaluate the proton magnetic resonance (MR) spectroscopy ((1) H MRS) changes in carriers of a novel octapeptide repeat insertion in the prion protein gene (PRNP) and family history of frontotemporal dementia with ataxia. Four at-risk mutation carriers and 13 controls were compared using single voxel, short TE, (1) H MRS from the posterior cingulate gyrus. The mutation carriers had an increased choline/creatine, P = .003 and increased myoinositol/creatine ratio, P = .003. (1) H MRS identified differences in markers of glial activity and choline metabolism in pre- and early-symptomatic carriers of a novel PRNP gene octapeptide insertion. These findings expand the possible diagnostic utility of (1) H MRS in familial prion disorders.
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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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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.
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Dural arteriovenous fistula (DAVF) of the anterior condylar canal is a rare subgroup of posterior fossa DAVF. Successful treatment of this DAVF requires an accurate image diagnosis and the knowledge of the anatomy of the anterior condylar confluent. We present the imaging features of angiography and MR angiography of a 54-year-old man, who presented progressive right synchronous tinnitus due to a DAVF of the anterior condylar confluent, successfully treated by transvenous embolization.
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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.