MR and clinical follow-up of diffusion-weighted cerebral lesions after carotid artery stenting.

PURPOSE: The purpose of this prospective study was to determine the outcome of postprocedural cerebral diffusion-weighted (DW) MR lesions after carotid artery stent placement (CAS) and the incidence of new cerebral MR lesions 6 months after the procedure. MATERIALS AND METHODS: DW and T2-weighted MR imaging of the brain and neurologic examinations were performed in 105 patients before and 24 hours and 6 months after CAS. In addition, a selective control angiography of the treated artery was performed after 6 months. RESULTS: In 22 (21%) of 105 patients, DW MR images 24 hours after CAS showed 64 new neurologically silent lesions; 2 (3.1%) of these 64 lesions were also visible in T2-weighted MR images. The latter ones were still visible after 6 months. In the remaining 62 lesions, there were no abnormalities visible in DW and T2-weighted imaging at follow-up. In 2 (1.9%) of the 105 patients, new cerebral lesions were seen in T2-weighted images after 6 months; one patient was neurologically symptomatic. All others patients were neurologically unremarkable at 6-month follow-up. CONCLUSIONS: Most postprocedural DW lesions showed no manifestations at 6-month MR follow-up and were clinically silent. This indicates that these lesions are potentially reversible and of no major neurologic sequelae. In addition, follow-up 6 months after CAS showed a very low incidence of new cerebral lesions and neurologic events.