Contrast-enhanced ultrasound imaging of carotid plaque neo-vascularization: accuracy of visual analysis

Abstract

The aim of our study was to evaluate whether neo-vascularization of the carotid plaque can be accurately assessed by visual analysis of contrast-enhanced ultrasound images and whether these findings correlate with intensity-over-time curve analysis (ITC) and histopathology. Patients with ≥50% symptomatic or ≥60% asymptomatic stenosis according to European Carotid Surgery Trial criteria were included. Four investigators evaluated contrast enhancement visually (three grades), with positive agreement when three or more investigators were unanimous. ITC analysis of contrast enhancement was performed in the plaque and in the lumen. Histopathology (microvessel density with CD34 + staining) was completed when endarterectomy was performed. Visual grading (33 patients, inter-observer agreement = 94%) correlated significantly with ITC analysis (p = 0.03). Histopathology (n = 19) revealed a larger CD34 + area in patients with grade 1/2 versus grade 0 (p = 0.03). Visual analysis of neo-vascularization by means of contrast-enhanced ultrasound imaging is accurate and reproducible, with significant correlations with ITC and histopathology.

Keywords: Contrast-enhanced ultrasound; Neo-vascularization; Stroke; Visual analysis; Vulnerable carotid plaque.