Carotid artery stenting is associated with the risk of periprocedural stroke. Moreover, modern magnetic resonance (MR) imaging techniques have found high rates of clinically silent ischemic brain lesions on post-treatment diffusion-weighted MR imaging (DWI) scans. The clinical significance of procedure-related DWI lesions, however, is still a matter of debate. This review article considers the frequency, location and pathophysiology of new DWI lesions on post-treatment MR images and summarizes available data on their clinical significance.