A Study on Distribution Features of Neovascularization in Atherosclerotic Carotid Artery Plaques: Comparing Contrast-enhanced Ultrasound with Histopathology

Intraplaque neovascularization (IPNV) is a characteristic feature of the vulnerable plaques. In this study of neovessels of carotid plaques, we assessed intraplaque echogenicity and plaque surface morphology, and performed contrast-enhanced ultrasound (CEUS) to observe the location and grading of neovessels to identify the vulnerability of plaques. The results showed that plaque with a ruptured fibrous cap on the histopathological images presented as a sunken or fissured surface on corresponding ultrasound images. Both in the symptomatic and asymptomatic groups, plaque echogenicity did not correlate with neovessels grading. The neovessels that appeared in the tunica media and base of the plaque in the symptomatic and asymptomatic group on CEUS had no statistical difference (p > 0.05), but those located in the fibrous cap and shoulders had a significant statistical difference (p = 0.000). Statistical differences were not found in the locations of IPNV on CEUS and histopathology (all p > 0.05). The sensitivity (82.4%, 56/68) and specificity (77.4%, 24/31) of IPNV location were higher than those (77.9%, 53/68; 45.2%, 14/31) of IPNV grading in the identification of plaque vulnerability. IPNVs located at the fibrous cap and shoulders on CEUS is a reliable indicator for identifying plaque vulnerability.