Purpose: To analyze the relationship among distribution location, characteristics, and vulnerability of carotid plaque using CTA and provide more information on the risk factors of carotid atherosclerotic plaque.
Patients and Methods: We retrospectively analyzed the CTA images of the head and neck of 93 patients with carotid atherosclerosis. Atherosclerosis was developed in 148 carotid arteries. The plaques were divided into a high-risk plaque group and a low-risk plaque group according to whether the plaques had high-risk characteristics. The maximum cross-sectional area of carotid artery bifurcation plaque on the axial image was selected, and the cross-sectional lumen was equally divided into four 90-degree sectors, ventral side wall, dorsal side wall, inner side wall, and outer side wall. The differences in the characteristics and distribution locations of the plaques in the two groups were analyzed. The characteristic parameters of the cross-sectional plaques at the bifurcation of the carotid artery. The logistic regression analysis was used to further analyze the risk factors associated with plaque vulnerability.
Results: Among 148 carotid arteries,80 were classified as high-risk and 68 as low-risk groups. There were significant differences between the two groups concerning the thickness, length, maximum cross-sectional area, burden, and cross-sectional distribution of the plaques (P < 0.05). The plaque distribution on the dorsal side wall of the carotid bifurcation was higher in the high-risk group than that in the low-risk group (P < 0.05), dorsal side wall plaque-independent risk factors for the development of vulnerability of plaques in transient ischemic attack (TIA) patients (95% CI:1.522~6.991, P< 0.05).
Conclusion: High-risk plaques tend to occur on the dorsal side wall of the carotid bifurcation, whereas low-risk plaques tend to occur on the outer side wall of the carotid bifurcation.

Keywords: carotid artery, plaque morphology, plaque vulnerability, atherosclerosis, plaque distribution