Association Between Carotid Atherosclerotic Plaque Calcification and Intraplaque Hemorrhage

Vulnerable atherosclerotic plaque in carotid arteries is a major cause of cerebrovascular events, such as transient ischemia attack and ischemic stroke. Previous studies have shown that compositional characteristics, particularly intraplaque hemorrhage (IPH) and lipid-rich necrotic core, in carotid artery plaques play a key role in plaque vulnerability. In particular, it is increasingly evidenced that IPH is one of the most effective predictors for cardiovascular events because of its stimulating plaque progression by a sharp increase of free cholesterol and macrophage infiltration resulting from erythrocyte membranes. Furthermore, it has been reported that the presence of IPH and increased IPH volumes lead to significant increase in critical plaque wall stress and strain and subsequently contribute to plaque instability. To date, the pathogenesis of IPH is still unclear. Most investigators think that the rupture of immature neovessels may be the pathological basis. Neovessels can be affected by multiple factors, such as blood pressure, plaque compositions, and hemodynamic parameters in carotid plaques. A previous study has demonstrated a significant association between IPH detected by MPRAGE (magnetization-prepared rapid gradient-echo) and calcification detected by computed tomography angiography. The investigators also found that calcification may play a role in the occurrence of IPH. To our knowledge, few studies have been performed investigating the relationship between calcification and IPH. Xu et al have demonstrated that the location and shape of superficial calcifications in carotid plaques were associated with IPH