Journal of neuroimaging : official journal of the American Society of Neuroimaging
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The H63D-HFE single nucleotide polymorphism (SNP) has been associated with brain iron dysregulation; however, the emergent role of this missense variant in brain structure and function has yet to be determined. Previous work has demonstrated that HFE SNP carriers have reduced white matter magnetic resonance imaging (MRI) proton relaxation rates. The mechanism by which white matter alterations perturb MRI relaxation is unknown as is how these metrics are related to myelin integrity. ⋯ The MRI data presented here demonstrate that H63D-HFE polymorphism carriers have diffusivity changes in white matter compared to wild-type subjects. The reduced integrity white matter tracts in H63D-HFE carriers are hypothesized to be related to increased susceptibility of these late-myelinating regions to cellular stress induced by oligodendrocyte iron dyshomeostasis.
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Diffusion-weighted magnetic resonance imaging tractography can be used to create models of white matter fascicles. Anatomical and pathological variability between subjects can drastically alter the tractography output, so standardizing results across a cohort is nontrivial. Furthermore, tractography methods have inherently low reproducibility due to stochasticity (for probabilistic methods) and subjective decisions, since the final fascicle model often requires a manual intervention step performed by an expert human operator to control both outliers and systematic false-positive pathways, as defined by prior knowledge of anatomy. ⋯ This method is intended to replace the application of a streamline density threshold so that outliers are eliminated based on low pathway density instead of voxel-wise density.
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Physiologic asymmetry of transverse sinus (TS) caliber is common and can lead to misinterpretation of magnetic resonance venography (MRV) studies of the brain. This retrospective study assesses the ability of multiple anatomic features on axial noncontrast T1-weighted images (T1WIs) of the brain to predict congenital TS dominance. ⋯ Multiple anatomic features seen on conventional axial T1WI can be used to predict the laterality of congenital TS dominance and can help inform the interpretation of MRV studies of the brain.
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In acute stroke, thromboembolism or spontaneous hemorrhage abruptly reduces blood flow to a part of the brain. To limit necrosis, rapid radiological identification of the pathological mechanism must be conducted to allow the initiation of targeted treatment. The aim of the Norwegian Acute Stroke Prehospital Project is to determine if anesthesiologists, trained in prehospital critical care, may accurately assess cerebral computed tomography (CT) scans in a mobile stroke unit (MSU). ⋯ This pilot study shows that anesthesiologists trained in prehospital critical care may effectively assess cerebral CT scans in an MSU, and determine if there are radiological contraindications for thrombolysis.
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Nerves and nerve ganglions are supplied by segmental arteries and the vasa nervorum, but the intra-arterial route has not been used for diagnostic or therapeutic purposes. We present the results of intra-arterial delivery of medication for modulating trigeminal nerve ganglion function in patients with refractory trigeminal neuralgia. ⋯ We found that modulation of trigeminal nerve activity via the intra-arterial route is possible based on consistent intraprocedural electrophysiologic suppression and short-term clinical improvement in patients with refractory trigeminal neuralgia.