Efficacy of high-resolution cone-beam CT in the evaluation of carotid atheromatous plaque

Abstract

IntroductionA major disadvantage of carotid artery stenting (CAS) is the high incidence of perioperative cerebral embolism. Cerebral embolism after CAS is associated with soft plaque. Currently, higher spatial resolution imaging can be obtained with cone-beam CT (CB-CT). The correlation between the degree of contrast enhancement of the vasa vasorum (VV) on CB-CT and the vulnerability of plaque in terms of risk factors for CAS was evaluated.Methods18 patients who underwent CAS had high-resolution CB-CT to evaluate enhancement of the VV covering carotid plaque performed intraoperatively. The appearance of the surface of the carotid plaque was classified as either enhancing (VV-positive) or non-enhancing (VV-negative). Carotid plaque vulnerability on black-blood MRI (BB-MRI) and postoperative ipsilateral ischemic lesions on diffusion-weighted imaging (DWI) were analyzed in the two groups.ResultsOf the 18 patients, 9 were VV-positive and 9 were VV-negative. The proportion of ipsilateral new ischemic lesions on DWI was significantly higher in the VV-positive group than in the VV-negative group (8/9 patients (88.9%) vs 3/9 patients (33.3%), p=0.026). BB-MRI was performed preoperatively in 15 of 18 patients. The proportion of unstable plaque on BB-MRI was significantly higher in the VV-positive group than in the VV-negative group (9/9 patients (100%) vs 1/6 patients (16.7%), p=0.002).ConclusionsEnhancement of the VV covering carotid plaque on high-resolution CB-CT was significantly associated with unstable plaque on BB-MRI and postoperative ipsilateral new ischemic lesions.