Plaque Rupture in the Carotid Artery Is Localized at the High Shear Stress Region

Abstract

Background and Purpose— Cerebrovascular events are related to atherosclerotic disease in the carotid arteries and are frequently caused by rupture of a vulnerable plaque. These ruptures are often observed at the upstream region of the plaque, where the wall shear stress (WSS) is considered to be highest. High WSS is known for its influence on many processes affecting tissue regression. Until now, there have been no serial studies showing the relationship between plaque rupture and WSS. Summary of Case— We investigated a serial MRI data set of a 67-year-old woman with a plaque in the carotid artery at baseline and an ulcer at 10-month follow up. The lumen, plaque components (lipid/necrotic core, intraplaque hemorrhage), and ulcer were segmented and the lumen contours at baseline were used for WSS calculation. Correlation of the change in plaque composition with the WSS at baseline showed that the ulcer was generated exclusively at the high WSS location. Conclusions— In this serial MRI study, we found plaque ulceration at the high WSS location of a protruding plaque in the carotid artery. Our data suggest that high WSS influences plaque vulnerability and therefore may become a potential parameter for predicting future events.