Diffusion-weighted MR imaging after angioplasty or angioplasty plus stenting of arteries supplying the brain

BACKGROUND AND PURPOSE: There has been concern regarding the safety of reva scularization procedures of vessels supplying the brain vessels because of the risk of cerebral embolization during the procedure. We have observed a high incidence of hyperintense lesions on diffusion-weighted MR images of t he brain after stenting at the carotid bifurcation. The hypothesis of this study is that diffusion-weighted MR imaging of the brain can reveal new dif fusion abnormalities after angioplasty or angioplasty plus stenting of arte ries supplying the brain, other than at the carotid bifurcation. Therefore, we prospectively obtained diffusion-weighted MR images of the brain before and after such revascularization procedures. METHODS: Thirty-seven revascularization procedures were performed in 32 pat ients. Eleven interventions were performed at the distal internal carotid a rtery, two at the external carotid artery, two at the common carotid artery , five at the innominate artery, five at the vertebral artery, and 12 at th e proximal subclavian artery. Diffusion-weighted MR imaging of the brain wa s performed before and 24 hours after the procedures. RESULTS: After eight (22%) of 37 procedures, new hyperintensities were visi ble on the diffusion-weighted MR images. With six of these eight procedures , the hyperintensities occurred in the vascular territory supplied by the t reated vessel. In total, 35 new cerebral lesions could be seen, 33 (94%) of which occurred in the vascular territory supplied by the treated vessel. N one of the patients in whom new diffusion abnormalities were found had new neurologic symptoms or deficits. No new lesions could be seen after procedu res at the subclavian artery. CONCLUSION. Revascularization procedures of arteries supplying the brain we re associated with new lesions on the diffusion-weighted MR images of the b rain after 22% of the procedures, provided that MR imaging could be perform ed, indicating the occurrence of cerebral microemboli during such procedure s. Diffusion-weighted MR imaging of the brain can be used as a tool to asse ss the impact of modifications of procedural technique and/or the use of ce rebral protection devices on the occurrence of such lesions.