Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Comparative Study
Vertebral artery ostial stenosis: prevalence by digital subtraction angiography, MR angiography, and CT angiography.
(1) To determine the prevalence of vertebral arterial ostial stenosis (VOS) as determined by the "gold standard" of digital subtraction angiography (DSA). (2) To learn the correlation between vertebral ostial stenosis and study indication. (3) To determine the ability of contrast-enhanced magnetic resonance angiography (CE MRA) and computed tomographic angiography (CTA) to reflect the true prevalence of vertebral ostial stenosis as determined by DSA. ⋯ The prevalence of VOS as determined by DSA is low and increases with patient age and correlates with factors such as anterior infarct (18.4%), posterior infarct (33.3%), carotid atherosclerosis (30.8%), and vertebrobasilar insufficiency (33%). Patients being evaluated for reasons less closely correlated with atherosclerotic disease, such as arteriovenous malformation (AVM) or hemorrhage showed a lower prevalence of VA stenosis (brain aneurysm or AVM 5/121, 4.1%, brain hemorrhage 5/153, 3.3%). Routine clinical MRA significantly overestimates VOS prevalence, and findings suggest that CTA underestimates the degree and prevalence of VOS.
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The aim of our study was to evaluate flat detector computed tomography angiography with peripheral intravenous contrast material application (FD-CTA) for visualization of cerebral arteries in comparison with intravenous multidetector computed tomography angiography (CTA) and intraarterial digital subtraction angiography (DSA). ⋯ The results suggest that the cerebral arteries can be visualized by FD-CTA in high resolution, in many vessel segments comparable to DSA.
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Idiopathic intracranial hypertension (IIH), is characterized by elevated intracranial pressure (ICP) without a clear cause. Recently it was shown that in more than 90% of the IIH patients there is stenosis of the transverse dural sinuses. In this study we assessed the changes in diameter of cerebral veins after lumbar puncture, in order to have some more insight regarding the volume and pressure influence on cerebral veins. ⋯ Our results support other studies and demonstrated narrowing of the transverse sinuses in IIH patients. The main finding of this study is the increase in cerebral sinuses diameter after LP. This observation should be considered when evaluating cerebral venous sinuses after LP. A larger scale study is warranted to validate our findings.
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To determine the interobserver reliability of a newly proposed classification scheme for angiographic classification of spinal vascular malformations including arteriovenous fistulas (AVFs) and arteriovenous malformations (AVMs). ⋯ The new classification scheme provided satisfactory reliability even in the hands of less experienced observers. The scheme can be used with minimal training and other concurrent data and can be relied upon to provide consistent results.
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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.