Eccentric narrowing and enhancement of symptomatic middle cerebral artery stenoses in patients with recent ischemic stroke.

OBJECTIVE To characterize the vessel wall imaging findings and enhancement patterns in the middle cerebral artery of patients with presumed atherosclerotic disease and recent infarction in the territory of the affected artery. DESIGN Case series. SETTING University hospital. PATIENTS We included patients with (1) 2 or more risk factors for atherosclerotic disease; (2) middle cerebral artery stenosis shown on computed tomography, magnetic resonance, or conventional angiography; and (3) recent infarction in the territory of the affected artery. INTERVENTION 3-T contrast-enhanced high-resolution magnetic resonance imaging. RESULTS Eight patients were identified: 6 had an eccentric M1 stenosis, 1 had an eccentric proximal M2 stenosis, and 1 had a distal M2 stenosis with inconclusive eccentricity. Enhancement of the lesion was observed in all patients who underwent scanning within 5 months of the index event. Four intracranial atherosclerotic plaques were found in asymptomatic vessels (1 contralateral middle cerebral artery and 3 other intracranial arteries), and none of these had enhancement. CONCLUSION Patients with presumed intracranial atherosclerosis of the middle cerebral arteries have eccentric plaques that enhance after the administration of contrast medium when imaging is performed within weeks to months of a cerebral infarct within the arterial territory.