Compensatory remodeling in symptomatic middle cerebral artery atherosclerotic stenosis: a high-resolution MRI and microemboli monitoring study

OBJECTIVE: To investigate the existence of an association between compensatory remodeling in symptomatic middle cerebral artery atherosclerotic stenosis with high-resolution magnetic resonance imaging (HR MRI) and transcranial color Doppler monitoring of microembolic signals (MESs). METHODS: A total of 36 consecutive patients with symptomatic middle cerebral artery atherosclerotic stenosis underwent MES monitoring by transcranial color Doppler and 3-T HR MRI. Proton density-weighted cross-sectional images with submillimeter voxel size were obtained. The remodeling patterns and plaque morphology of the sites of maximal luminal narrowing were analyzed in terms of their association with the MES data. RESULTS: Positive remodeling (PR) was found in 16 lesions (44·4%). The remodeling index was 1·11±0·05 in the PR group and 0·99±0·05 in the non-PR group (P<0·0001). Compared with the non-PR group, the PR group had a greater vessel area (19·97±1·42 mm(2) versus 18·23±1·23 mm(2)) and greater wall area (16·93±1·47 mm(2) versus 14·93±1·52 mm(2); both P<0·0001) at the sites of maximal luminal narrowing. Finally, MESs were observed more frequently in the PR group than in the non-PR group (62·5% versus 15·0%, P = 0·003). CONCLUSIONS: In patients with symptomatic middle cerebral artery atherosclerotic stenosis, MESs were observed more frequently in the PR group than in the non-PR group.