Journal of neuroimaging : official journal of the American Society of Neuroimaging
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CT Perfusion in Acute Stroke: "Black Holes" on Time-to-Peak Image Maps Indicate Unsalvageable Brain.
CT perfusion is becoming important in acute stroke imaging to determine optimal patient-management strategies. The purpose of this study was to examine the predictive value of time-to-peak image maps and, specifically, a phenomenon coined a "black hole" for assessing infarcted brain tissue at the time of scan. ⋯ Black holes on time-to-peak image maps represent areas of unsalvageable brain.
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Because clinical evaluation of noncontrast computed tomography (CT) has a poor sensitivity in the evaluation of acute ischemic stroke, computer-aided diagnosis may be able to facilitate the performance. Recently, we introduced a computational method for the detection and localization of visible infarcts. Herein, we aimed to evaluate and extend a previous method, the Stroke Imaging Marker (SIM), to localize nonvisible hyperacute ischemia. ⋯ The improved SIM is a dedicated and potentially useful tool for hyperacute nonvisible brain infarct detection from CT scans and may contribute to reduction of image-to-needle time in patients eligible for revascularization therapy.
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There is considerable amount of interindividual variability in the size and location of the vascular territories of the major brain arteries. More data are needed to assess the amount of variability and the possible implications for further research and patient care. Arterial spin labeling (ASL) magnetic resonance imaging has been applied in various forms to facilitate noninvasive imaging of cerebrovascular flow territories, but it requires the definition of the flow territory of interest prior to image acquisition. ⋯ Further technical improvements in imaging and segmentation techniques will improve the accuracy of the method and will facilitate the delineation of flow territories after image acquisition on even smaller subtrees of the cerebral vasculature.
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A voxel-based statistical approach on computer tomographic data in patients with intracerebral hemorrhage (ICH) and acute intraventricular hemorrhage (IVH) was used to evaluate spatial and temporal patterns of intraventricular blood in patients treated with intraventricular fibrinolysis (IVF) or without. ⋯ The data indicate that voxel-based analysis on group level can be used to compare the time course and the distribution of intraventricular hemorrhage. This technique could be an interesting tool for future research on ICH with IVH.
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Review Meta Analysis
White Matter Diffusion Abnormalities in Carotid Artery Disease: A Systematic Review and Meta-Analysis.
Abnormalities in apparent diffusion coefficient (ADC), fractional anisotropy (FA), and mean diffusivity (MD) values can be used to assess microstructural damage to white matter tracts and could represent a quantitative marker of chronic ischemia and thereby potentially serve as a stroke risk factor or a measure of existing subclinical ischemic disease burden. We performed a systematic review and 3 separate meta-analyses to evaluate the association between unilateral carotid steno-occlusion and ipsilateral ADC, FA, or MD abnormality. ⋯ Carotid artery disease is associated with significant ADC and FA value changes, suggesting that carotid disease is associated with quantifiable white matter microstructural damage.