Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Perivascular spaces (PVSs), also known as Virchow-Robin spaces, are pial-lined, fluid-filled structures found in characteristic locations throughout the brain. They can become abnormally enlarged or dilated and in rare cases can cause hydrocephalus. ⋯ In addition, various pathologic processes, including cryptococcosis and chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids, can spread into the brain via PVSs, resulting in characteristic magnetic resonance imaging appearances. This review aims to describe the key imaging characteristics of normal and dilated PVSs, as well as cystic mimics and pathologic processes that directly involve PVSs.
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To determine the sensitivity and specificity of the hyperdense artery sign (HAS) on thin-slice non-contrast computed tomography (NCCT), combined with brief clinical history, as an indicator for large vessel occlusion (LVO) in the setting of acute ischemic stroke. ⋯ The HAS on thin-slice NCCT has a reasonably high sensitivity and specificity for identifying LVO in acute ischemic stroke patients presenting with an NIHSS > 10 and suspected MCA M1 or basilar artery occlusion.
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Magnetization transfer ratio (MTR), a magnetic resonance imaging technique used to assess tissue integrity, correlates with demyelination and axonal loss in multiple sclerosis (MS) lesions. In acute white matter lesions, short-term MTR changes mainly reflect demyelination and remyelination, in addition to edema and axonal and glial changes. Long-term MTR changes in MS lesions have not been studied extensively. ⋯ These results suggest that long-term changes in MTR in white matter lesions can be used to distinguish lesion subtypes associated with MS disease progression and improve understanding of the temporal evolution of MS pathology.
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Studies in animal models suggest that inflammation is a major contributor to secondary injury after intracerebral hemorrhage (ICH). Direct, noninvasive monitoring of inflammation in the human brain after ICH will facilitate early-phase development of anti-inflammatory treatments. We sought to investigate the feasibility of multimodality brain imaging in subacute ICH. ⋯ Our study demonstrates for the first time the feasibility of performing complex multimodality brain imaging for noninvasive monitoring of neuroinflammation for this severe stroke subtype.
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Diffusion magnetic resonance imaging (dMRI) provides preoperative maps of neurosurgical patients' white matter tracts, but these maps suffer from echo-planar imaging (EPI) distortions caused by magnetic field inhomogeneities. In clinical neurosurgical planning, these distortions are generally not corrected and thus contribute to the uncertainty of fiber tracking. Multiple image processing pipelines have been proposed for image-registration-based EPI distortion correction in healthy subjects. In this article, we perform the first comparison of such pipelines in neurosurgical patient data. ⋯ Quantitative results of mean tract distortions on the order of 1-2 mm are in line with other recent studies, supporting the potential need for distortion correction in neurosurgical planning. Novel results include significantly higher distortion estimates in the tumor hemisphere and greater effect of image resolution choice on results in the tumor hemisphere. Overall, this study demonstrates possible pitfalls and indicates that care should be taken when implementing EPI distortion correction in clinical settings.