Vessel-Wall Magnetic Resonance Imaging of Intracranial Atherosclerotic Plaque and Ischemic Stroke: A Systematic Review and Meta-Analysis

Abstract

Introduction: Vessel-wall magnetic resonance imaging (MRI) has been suggested as a valuable tool for assessing intracranial arterial stenosis with additional diagnostic features. However, there is limited conclusive evidence on whether vessel-wall MR imaging of intracranial atherosclerotic plaques provides valuable information for predicting vulnerable lesions. We conducted this systematic review and meta-analysis to evaluate which characteristics of intracranial-plaque on vessel-wall MRI are markers of culprit lesions. Methods: The MEDLINE, EMBASE, and Cochrane Library of Clinical Trials databases were searched for studies reporting the association between vessel-wall MRI characteristics of intracranial plaque and corresponding stroke events. Odds ratios (ORs) for the prevalence of stroke with intracranial-plaque MRI characteristics were pooled in a meta-analysis using a random-effects model. Results: Twenty studies were included in this review. We found a significant association between plaque enhancement (OR, 10.09; 95% CI, 5.38-18.93), positive remodeling (OR, 6.19; 95% CI, 3.22-11.92), and plaque surface irregularity (OR, 3.94; 95% CI, 1.90-8.16) with stroke events. However, no significant difference was found for the presence of eccentricity (OR, 1.22; 95% CI, 0.51-2.91). Conclusion: Based on current evidence, intracranial plaque contrast enhancement, positive remodeling, and plaque irregularity on MRI are associated with increased risk of stroke events. Our findings support the design of future studies on intracranial-plaque MRI and decision making for the management of intracranial atherosclerotic plaques.

Keywords: brain ischemia–diagnosis; cerebrovascular accident; high resolution imaging; intracranial arteriosclerosis; magnetic resonance imaging; plaque; systematic (literature) review; vessel wall imaging.

Figures

Figure 1

PRISMA flow diagram of studies identification.

Figure 2

Forest plots for association between vessel-wall MRI findings and ischemic event. Forest plots showing odds ratio (OR) presenting corresponding ischemic events of intracranial atherosclerotic plaques in comparison of positive and negative culprit signs on vessel-wall MRI. The size of the black box corresponding to each study is proportional to the sample size. The horizontal line shows the corresponding 95% confidence interval (CI) of the effect size (OR). The combined estimate is based on a randomized-effects model shown by the diamond. “Culp” and “T” indicate the number of culprit lesions and total lesions according to positive and negative signs of contrast enhancement (CE), eccentricity (Ecc), positive remodeling (PR), and surface irregularity (IR). •[(A)] Forest plot for contrast enhancement •[(B)] Forest plot for eccentricity •[(C)] Forest plot for positive remodeling •[(D)] Forest plot for surface irregularity.

Figure 3

Forest plot for association between intraplaque hemorrhage and ischemic event. Odd ratios and 95% confidence intervals demonstrating association between ischemic event and intraplaque hemorrhage in each enrolled study.

Figure 4

Contour-enhanced funnel plots for the assessment of publication bias. Dots represent point estimates plotted over standard error. Shaded areas represent a given level of significances (p-values of 0.01, 0.05, 0.1). •[(A)]Funnel plot for contrast enhancement. •[(B)] Funnel plot for eccentricity •[(C)] Funnel plot for positive remodeling •[(D)] Funnel plot for surface irregularity.