A case report of carotid stenosis treated with emergent carotid stenting: Usefulness of MR diffusion-weighted imaging for evaluation of microembolism

A 74-year-old male presented mild left hemiparesis due to multiple lacunar infarctions associated with bilateral carotid stenosis (left; 80%, right; 90%). After admission to our hospital he exhibited crescendo transient ischemic attacks and developed disorientation. MR diffusion-weighted imaging (DWI) before surgical treatment showed recent multiple embolisms in bilateral cerebral and right cerebellar hemispheres. Emergent stenting for the carotid stenosis was performed using a Palmaz stent. DWI the day after carotid stenting demonstrated cerebral embolisms that newly occurred just before and during the intervention, distinguishing recent ischemic lesions from previous ones. It was difficult to discriminate between acute embolisms and subacute ischemic lesions by CT and/or conventional MRI Studies. Since no additional ischemic lesions were observed by DWI 8 and 16 days following the intervention, carotid stenting was considered effective to prevent cerebral embolisms that arose from the stenotic lesion. Thus, DWI in the peri- operative period is useful to evaluate the benefits and ischemic complications of carotid stenting.