Journal of neuroimaging : official journal of the American Society of Neuroimaging
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High field strength functional magnetic resonance imaging (fMRI) has developed rapidly. However, it suffers from increased artifacts in brain regions such as the medial temporal lobe (MTL), challenging functional imaging of the hippocampus with the objective of high-spatial resolution, which is particularly useful for this region both from a clinical and cognitive neuroscience perspective. We set out to compare a BOLD sequence at 7 T versus 3 T to visualize the MTL activity during an associative memory-encoding task. ⋯ Analyses of task-related fMRI data revealed robust activations in the bilateral MTL during associative memory encoding at both field strengths. Notably, we observed significantly stronger memory-related hippocampal activation at 7 T than at 3 T, suggesting higher BOLD sensitivity at 7 T. These results are discussed in the light of the feasibility of 7 T scanning protocols for the MTL.
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Here we describe the imaging findings in a 73-year-old woman who had pain in the right inguinal region, followed by progressive weakness of muscles innervated by the right femoral and obturator nerves, diagnosed as nondiabetic lumbosacral radiculoplexus neuropathy. Magnetic resonance neurography showed thickening and increase in signal intensity of the right femoral and obturator nerves.
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Ganglioneuromas are uncommon, benign, and highly differentiated tumors arising from sympathetic ganglia. Common sites for these tumors include the paraspinal region of the retroperitoneum and posterior mediastinum. We report a case of a retropharyngeal ganglioneuroma, a rare occurrence, emphasizing its key imaging characteristics.
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The detection of microembolic signals in transcranial-Doppler monitoring is associated with a higher stroke risk. We investigated the correlation between the frequency of microembolic signals and the efficacy of the antiplatelet therapy in patients with a recent symptomatic carotid-artery stenosis. ⋯ Our study suggests that in patients with recent symptomatic carotid-artery stenosis the detection of more than one microembolic signals might serve as a useful marker for the effectiveness of the antiplatelet treatment.
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The effect of oversized intracranial stent implantation, and potential excessive neointimal hyperplasia from the chronic outward radial force, has not been reported. We sought to compare the angiographic narrowing associated with implantation of oversized stents. ⋯ A small significant lumen loss occurs at stent tines when compared to midstent struts. However, there is no overall significant stenosis from highly oversized stents. Persistent luminal gain from the oversized stent radial force likely predominates over any neointimal hyperplasia.