Shape and Location of Carotid Atherosclerotic Plaque and Intraplaque Hemorrhage: A High-resolution Magnetic Resonance Imaging Study

Aim: The present study aimed to investigate the association between shape and location of atherosclerotic plaques and intraplaque hemorrhage (IPH) in carotid arteries using magnetic resonance (MR) imaging. Methods: Overall, 114 symptomatic patients (mean age: 64.9±10.9 years; 81 males) who underwent MR imaging and had advanced carotid plaques were included in analysis. IPH presence and carotid plaque shape and location (below and above bifurcation) were evaluated. The plaque shape was defined as follows: type-I: the arc-length of plaque is greater in the upstream; type-II: the arc-length of plaque in downstream and upstream is equal; and type-III: the arc-length of plaque is greater in downstream. The plaque shape and location were compared between plaques with and without IPH and their associations with IPH were determined. Results: Of 181detectedplaques, 57 (31.5%) had IPH. Compared with plaques without IPH, those with IPH had higher incidence of the plaque shape of type-I (66.7% vs. 32.2%, P<0.001), lower incidence of plaque shape of type-III (24.6% vs. 50.0%, P=0.001), and were more likely located above carotid bifurcation (71.9% vs. 48.4%, P=0.003). The plaque shape of type-I (OR, 4.01; 95%CI, 1.36–11.83; P=0.012) and location above bifurcation (OR, 3.21; 95%CI, 1.07–9.61; P=0.037) of carotid plaques were significantly associated with IPH after adjusting for confounder factors. Conclusions: Carotid plaque shape and location are significantly associated with the occurrence of IPH. Our findings could provide new insights for the pathogenesis of IPH and vulnerably plaques.