Diffusion/perfusion-weighted magnetic resonance imaging after carotid angioplasty and stenting

Carotid angioplasty and stenting, a so far non-validated procedure, may be an alternative to surgery in patients with a high surgical risk. However, it carries also a risk of cerebral embolic events. The purpose of this study was to evaluate tissue signal abnormalities in the brain before and after carotid angioplasty and stenting by means of diffusion- (DWI) and perfusion (PWI) weighted magnetic resonance imaging (MRI).

We performed cerebral MRI before and after carotid angioplasty in 22 consecutive patients, with 23 treated high-grade carotid stenoses. The lesions were located at the origin of the internal carotid artery (ICA) in 20 patients, and at the origin of the common carotid artery (CCA) in 2. MRI was performed the day before, and repeated within 24 hours after the procedure, and examined by two neuroradiologists.

All stent implantations were successful but 4 patients developed an acute neurological deficit within 24 hours after carotid angioplasty. On PWI, Time To Peak (TTP) values ipsilateral to the carotid stenosis were increased before the procedure in 15 patients, and had remained normal in 6 and were not assessable in 1. After the procedure, TTP values were normal in 12 patients, increased in 8 and not assessable in 2. On DWI, new ipsilateral lesions were detected in 2 patients: 1 with an acute neurological deficit and 1 symptom free.

Perfusion deficits may be present in severe carotid stenosis and be improved within 24 hours by carotid angioplasty and stenting. Asymptomatic infarcts may occur.