Diffusion Tensor Imaging in Patients With Major Cerebral Artery Occlusive Disease

Abstract

Diffusion tensor (DT) imaging provides quantitative information about the magnitude and the directionality (anisotropy) of water diffusion in vivo and can detect pathologic changes in brain ischemia. This study tried to detect ischemic brain damage using DT imaging in patients with symptomatic chronic major cerebral artery occlusive disease. DT imaging was performed using a 3.0 Tesla magnetic resonance (MR) scanner in 50 patients with unilateral internal carotid artery or middle cerebral artery stenosis or occlusion, who had no obvious infarct lesions on conventional MR imaging. Thirty-three patients underwent DT imaging before and after vascular reconstruction surgery. Fractional anisotropy (FA) was calculated in the middle cerebral artery territory. Preoperative FA values in the ipsilateral side were significantly lower than those in the contralateral side. After surgery, the FA value was significantly increased. DT imaging may indicate ischemic brain damage, not visualized by conventional MR imaging, in patients with major cerebral artery occlusive disease.

White Matter Diffusion Abnormalities in Carotid Artery Disease: A Systematic Review and Meta‐Analysis

“…The 6 studies included were prospective ( n = 4) and retrospective ( n = 2) studies with MRI of the brain performed on either 1.5T ( n = 1) or 3T scanners ( n = 5) . A total of 230 patients were included.…”

“…All studied patients had at least 70% carotid artery stenosis by either duplex US, CTA, MRA, or DSA defined by NASCET criteria . In 4 studies, both symptomatic and asymptomatic patients were included without separating the cohorts while 1 studied only asymptomatic patients . One study included both symptomatic and asymptomatic patients but evaluated the cohorts separately .…”

“…One study included both symptomatic and asymptomatic patients but evaluated the cohorts separately . Four studies used a b‐value of less than 1,300 while 1 study only used b‐values greater than 1,300 . One studied the same cohort separately using b‐values both greater and less than 1,300 .…”

Quantitative High-Field Diffusion Tensor Imaging of Cerebral White Matter in Asymptomatic High-Grade Internal Carotid Artery Stenosis

“…These studies vary significantly in terms of study design and patient selection. Inoue et al [4] compared FA values from a ROI-based analysis in the centrum semiovale of both hemispheres in 30 symptomatic patients and found reduced values on the affected side. In this study, no analysis of pre-existing white matter lesions was performed and no information concerning the neurological status of the patients is given.…”

“…An ongoing multicenter trial is comparing interventional methods with up-to-date medical prophylaxis in the treatment of asymptomatic ICAS [3]. Whereas the aim of these different approaches is primary prophylaxis of ischemic cerebral stroke, several groups have reported an increase of diffusion of free water molecules in cerebral tissue of the dependent hemisphere downstream to an ICAS in symptomatic as well as asymptomatic patients [4,5,6], which might indicate subtle tissue damage. The deleterious effect of chronic hypoperfusion on brain tissue has been postulated to be one explanation for this observation [7].…”