Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Thresholds for abnormal transcranial Doppler cerebrovascular reactivity (CVR) studies are poorly understood, especially for patients with cerebrovascular disease. Using a real-world cohort with cerebral arterial stenosis, we sought to describe a clinically significant threshold for carbon dioxide reactivity (CO2R) and vasomotor range (VMR). ⋯ In patients with multiple vascular risk factors, a reasonable threshold for clinically significant abnormal CO2R is <0.80% and VMR is <7.9%. Noninvasive CVR may aid in diagnosing and risk stratifying patients with stenosis.
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To present the first study analyzing the clinical and radiological course of carotid-cavernous fistulas (CCFs) following incomplete embolization. The study compares magnetic resonance angiography (MRA) to plain angiography (digital subtraction angiography [DSA]) and investigates the long-term ophthalmological impact of residual fistula. ⋯ The goal of CCF treatment is safe and complete embolization. However, if adequate flow reduction is achieved, both direct and indirect CCFs tend to spontaneously thrombose. Residual flow does not result in ophthalmological deterioration until the fistula is completely closed. MRA may not be sufficiently sensitive to detect residues of fistulas including cortical venous drainage. Therefore, complete CCF closure should be confirmed through DSA.
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The purpose of this study is to evaluate the feasibility of using 3-dimensional (3D) ultra-short echo time (UTE) radial imaging method for measurement of the permeability of the blood-brain barrier (BBB) to gadolinium-based contrast agent. In this study, we propose to use the golden-angle radial sparse parallel (GRASP) method with 3D center-out trajectories for UTE, hence named as 3D UTE-GRASP. We first examined the feasibility of using 3D UTE-GRASP dynamic contrast-enhanced (DCE)-magnetic resonance imaging (MRI) for differentiating subtle BBB disruptions induced by focused ultrasound (FUS). Then, we examined the BBB permeability changes in Alzheimer's disease (AD) pathology using Alzheimer's disease transgenic mice (5xFAD) at different ages. ⋯ The results in this study substantiate the feasibility of using the proposed 3D UTE-GRASP method for detecting subtle BBB permeability changes expected in neurodegenerative diseases, such as AD.