An evaluation of dual source computed tomography used with the de Weert classification to detect vulnerable plaque, using IVUS virtual histology as a standard of reference.

Abstract

One of the main risk factors for cerebral ischemic events is atherosclerotic disease of the internal carotid artery (ICA). Nowadays, increasing attention is being paid to the relationship between the morphological features of atherosclerotic plaque and the occurrence of stroke. Several studies have demonstrated that the presence of specific vulnerable plaque types, with a large lipid core and thin fibrous cap, can be used as an independent risk predictor of cerebral ischemic events. The present study is an attempt to develop the method of plaque surface morphology assessment presented by de Weert et al. by correlating the results of Dual Source Computed Tomography (DSCT) with those from intravascular ultrasound virtual histology (IVUS-VH). A group of 30 symptomatic patients (13 men and 17 women; 72 ± 9 years) with ICA stenosis suspected on the basis of ultrasound imaging (US) and confirmed to be above 70% in DSCT underwent intravascular ultrasound (IVUS) imaging. The results of DSCT were categorized according to the de Weert classification. There were 13 cases (43%) with smooth wall surfaces, 10 cases (33%) with discreet wall irregularities, and seven cases (23%) with incursions of contrast, indicating the presence of ulceration. In the IVUS-VH examinations, 4 out of 30 cases (13%) were identified as having adaptive intimal thickening (AIT), 4 (13%) as showing pathological intimal thickening (PIT), 6 (20%) with fibroatheromas (FA), six (20%) with fibrocalcific plaque (FCa), and 10 (33%) as having thin-cap fibroatheroma (TCFA), which is high-risk plaque. Comparing the above results showed that all the patients with confirmed wall ulceration in DSCT were characterized as having high-risk plaque in IVUS-VH. Using DSCT with the de Weert classification of plaque surface morphology makes reliable detection of ulcerations possible; therefore, this could become a significant new technique to improve current imaging protocols for patients with a high risk of ischemic cerebrovascular events.