[Carotid plaque composition and volume evaluated by multi-detector computed tomography angiography]

To evaluate the differences of plaquecomposition and volume between symptomatic and asymptomatic patients with carotid artery stenosis by multi-detector computed tomography angiography (MDCTA).

The consecutive patients with internal carotid artery stenosis≥70% diagnosed by digital subtraction angiography (DSA) were retrospectively analyzed from July 2011 to December 2015 in Peking University China-Japan Friendship School of Clinical Medicine. The symptomatic patients were defined as those who experienced nondisabling ischemic stroke or transient cerebralis chemic symptoms, including hemispheric events oramaurosis fugaxin the last 6 months. Otherwise, the patients were considered as a symptomatic. A total of 78 patients were enrolled in the study. Of these patients, there were 35 asymptomatic patients (44.9%) and 43 symptomatic patients (55.1%). All the patients received MDCTA before DSA. According to the plaque analysis of post processing work station, carotid plaques were divided into lipid-rich necrotic coreplaques (HU≤60), fibrous plaques (60 to 130 HU) and calcified plaques (HU≥130) through the different value sthreshold of HU. The plaque volume and proportion were all calculated. The differences between the two groups were compared by statistical methods.

The proportion of calcified plaques in asymptomatic patients was significantly higher than in symptomatic patients (t=2.760, P=0.007).And the proportion of LRNC plaqueswas lower than that in symptomatic patients (Z=2.009, P=0.044). There was statistical significance between the asymptomatic and symptomatic patients. Multivariate analysis showed that there was a positive correlation between the proportion of calcified plaques and asymptomatic carotid artery stenosis (OR=0.949; 95%CI: 0.915 to 0.985; P=0.005). The proportion of LRNC plaques showed a negative correlation with asymptomatic carotid artery stenosis (OR=1.068; 95%CI: 1.021 to 1.117; P=0.004). For the symptomatic patients, when the LRNC plaque proportion was greater than 30.3%, the specificity was 94.3%, and the sensitivity was 37.2%. There was no significant difference in plaque volume and fibrous plaque proportion in both groups.

Compared with symptomatic carotid plaques, the proportion of asymptomatic calcified plaques increased but the proportion of LRNC plaques decreased. Plaque LRNC 30.3% of the total volume may represent a clinically useful cutoff. For the patients with carotid artery stenosis, MDCTA may help noninvasively risk-stratify patients.