Contrast-Enhanced Ultrasound for the Evaluation of Neovascularization in Atherosclerotic Carotid Artery Plaques

Background and Purpose-Neovascularization associated with plaque vulnerability, particularly in the plaque shoulder, is susceptible to rupture, causing ischemic events. We aimed to use contrast-enhanced ultrasound to evaluate neovessels in carotid plaques quantitatively, focusing on plaque shoulders. Methods-Using contrast-enhanced ultrasound with perflubutane, we analyzed 50 consecutive patients who underwent carotid endarterectomy. We measured enhanced intensity and assessed the correlation between contrast effect and histopathology, comparing symptomatic and asymptomatic plaques. Results-Enhanced intensity of the plaque shoulder was associated with neovessel density (P<0.01; rho=0.43). Enhanced intensity of the plaque shoulder was higher in plaques with rupture than in those without (P<0.05), and in symptomatic plaques (n=31) than in asymptomatic ones (n=19; P<0.01). Conclusions-Quantitative evaluation of the contrast effect using contrast-enhanced ultrasound enabled the assessment of neovascularization of plaque shoulders in vivo real time, which may help stratify plaque vulnerability.