Objective To investigate the relationship between internal carotid artery angle (ICAA) and internal
carotid artery (ICA) plaque morphology in patients with acute anterior circulation infarction using
high resolution magnetic resonance imaging (HR-MRI).
Methods Patients with acute anterior circulation infarction admitted to Beijing Tian Tan Hospital
from November 2011 to June 2012 were enrolled in this study. All patients underwent HR-MRI
examination to obtain ICAA and plaque morphology data. According to the median of ICAA,
all patients were divided into ICAA ≥35° and <35° groups, and the amounts and characteristics
of carotid atherosclerotic plaques between the two groups were compared. Multi-factor logistic
regression analysis was performed to analyze the influencing factors of bilateral ICA plaques morphology.
Results A total of 162 ICA images from 86 patients were included in the final analysis, with 78
vessels in ICAA ≥35° group and 84 vessels in ICAA <35° group. The detection rate of ICA plaques
[92.3% (72/78) vs 56.0% (47/84), P <0.01] and vulnerable plaques [43.6% (34/78) vs 15.5% (13/84),
P =0.03] in ICAA ≥35° group were both higher than that in ICAA <35° group, with statistical
difference. The detection rate of lipid-rich necrotic core plaques [75.6% (59/78) vs 36.9% (31/84),
P <0.01] and intraplaque hemorrhage [26.9% (21/78) vs 11.9% (10/84), P =0.02] were higher in
ICAA ≥35° group than that in ICAA <35° group. Linear regression analysis showed that age was
an independent risk factor of plaque calcification volume on the left side (B 0.35, 95%CI 0.21-
1.65, P =0.01) and intra-plaque hemorrhage volume on the right side (B 0.34, 95%CI 0.30-2.32,
P =0.01), and the non-plane angle of ICAA was an independent risk factor of lipid-rich necrotic core
volume in the plaques on the left side (B 0.37, 95%CI 1.23-7.33, P =0.01), and the non-plane angle
of external carotid artery was a risk factor of plaque calcification volume on the right side (B 0.33,
95%CI 0.20-2.07, P =0.02).
Conclusions With the increasing of ICA angle, the amount of plaques as well as vulnerable plaques
increased. ICAA was associated with the components and amount of carotid plaques, while it was
not an independent risk factor for carotid atherosclerosis.
