Basilar artery atherosclerotic plaques distribution in symptomatic patients: a 3.0T high-resolution MRI study.

PURPOSE: To investigate basilar artery atherosclerotic plaque distribution characteristics in symptomatic patients using 3.0T high-resolution MRI.

MATERIALS AND METHODS: Thirty-eight patients with recent ischemic strokes or transient ischemic attacks were included. Conventional angiographic luminal imaging of these patients showed at least 30% basilar artery stenosis. Patients then underwent basilar artery high-resolution MRI examinations (T2WI, T1WI and post-contrast enhanced T1WI in short axial and long axial views). The narrowest lumen plaque distribution was evaluated by cross-section division into four equal arcs (right, ventral, left and dorsal arcs) on the short axial T2-weighted images. The percent plaque fraction was calculated as arc plaque area/luminal area×100, with each compared by analysis.

RESULTS: The basilar artery lumens and walls were clearly shown in all 38 patients. The median plaque area sizes were 2.73mm(2) (range: 1.04-5.29mm(2)) on the ventral wall, 0.59mm(2) (range: 0-1.50mm(2)) on the left wall, 0.87mm(2) (range: 0-2.68mm(2)) on the dorsal wall, and 0.36mm(2) (range: 0-1.80mm(2)) on the right wall. The mean plaque fraction percentages were 21.6% (range: 7.9-34.0%) on the ventral wall, 4.6% (range: 0-10.0%) on the left wall, 6.3% (range: 0-16.3%) on the dorsal wall, and 2.6% (range: 0-12.9%) on the right wall. On the ventral wall, the plaque fraction percentage was significantly greater than the remaining three arcs (P=.000).

CONCLUSIONS: Basilar artery atherosclerotic plaques were mainly distributed at the ventral site of the artery. High-resolution MR examination may provide helpful information to minimize endovascular therapy risk complications in basilar artery atherosclerotic disease.