Purpose Our purpose is to investigate the feasibility of MR plaque imaging to predict the high risk lesion for ischemic complication during carotid artery stenting (CAS) using a filter embolic protection device (EPD).

Methods 100 carotid artery stenotic lesions in 96 patients before CAS (89 men and seven women; median age 72.2 years) were evaluated by MR plaque imaging with black blood T1 weighted images. The population consisted of 52% symptomatic stenosis, more than 50% at the common or internal carotid artery, and 48% asymptomatic stenosis more than 80% stenosis. All CAS procedures were performed by standard procedure using filter EPD (Angioguard XP). Main plaque components were classified into unstable plaque (intraplaque hemorrhage and lipid rich/necrotic core) and stable (fibrous tissue and dense calcification) from the signal pattern. Development of new ischemic lesions on diffusion weighted imaging was assessed within 48 h after CAS. We made statistical assessment on the plaque classification and the number of new ischemic lesions.

Results Technical success with the CAS procedures was achieved in 100 (100%) procedures. Ipsilateral new ischemic lesions were observed in 34 CAS procedures (34.0%). Ipsilateral multiple ischemic lesions (>10) were observed in seven CAS procedures (7%). In seven patients with multiple ischemic lesions, four showed minor strokes, two showed a transient ischemic attack and one was asymtopmatic. New ischemic lesions except multiple ischemic lesions were all asymtopmatic. There was no significant difference between unstable and stable plaques for the presence of new ischemic lesion. However, multiple ischemic lesions occurred significantly (p<0.01) more frequently in patients with unstable plaque.

Conclusions Presence of unstable carotid plaques showed a higher risk of ischemic complication of CAS with filter EPD than stable plaques.