Assessment of carotid atherosclerotic plaque using 3D motion- sensitized driven-equilibrium prepared rapid gradient echo: a comparative study

Abstract

Background: 3D motion-sensitized driven-equilibrium prepared rapid gradient echo (MERGE) can characterize carotid atherosclerotic plaque morphology and composition. The present study aimed to evaluate its performance by comparing it with reference images and assessing the inter-reader agreement.Methods: Eighty-four patients were prospectively recruited and scanned with 3D MERGE. Two trained magnetic resonance imaging (MRI) readers measured and calculated the maximum wall thickness (WT), maximum vessel diameter, total vessel area, lumen area, wall area, normalized wall index, plaque volume, intraplaque hemorrhage (IPH) volume, and calcification volume independently. IPH, calcification, mixed calcification, and ulceration were identified. The intraclass correlation coefficient (ICC) with 95% confidence interval (CI) was used to assess the inter-reader agreement. MERGE performance was assessed in terms of sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio, kappa value (κ), and the results of the Bland-Altman analysis and compared with reference images.Results: MERGE showed excellent inter-reader agreement (All ICCs >0.90). MERGE and simultaneous non-contrast angiography and intraplaque hemorrhage (SNAP) showed excellent agreement in detecting IPH (κ=0.938) and measuring IPH volume (ICC =0.995; 95% CI: 0.991-0.997). MERGE and computed tomography angiography (CTA) showed strong consistency in detecting calcification (κ=0.814) and mixed calcification (κ=0.972), and in measuring calcification volume (ICC =0.996; 95% CI: 0.993-0.997). MERGE and digital subtraction angiography (DSA) showed relatively strong consistency in identifying ulceration (κ=0.737).Conclusions: MERGE showed excellent performance in identifying and measuring IPH and calcification in carotid atherosclerotic plaques. Therefore, MERGE can be a promising imaging approach in atherosclerotic-vulnerable plaque.