Transcranial Doppler in Asymptomatic Carotid Stenosis Representing Hemodynamic Impairment: Correlation Study with Magnetic Resonance Imaging

BACKGROUND AND PURPOSE: Since the benefit of an endarterectomy in an asymptomatic carotid stenosis is not as clear as that in symptomatic stenosis, identifying patients with a high risk of stroke will allow the improved selection of surgical candidates. To evaluate the role of transcranial Doppler (TCD) in assessing an asymptomatic stenosis, this study examined the association of a TCD-detected hemodynamic change with a stenosis-related abnormality on magnetic resonance imaging (MRI). METHODS: Asymptomatic patients with a more than 60% internal carotid artery stenosis were enrolled in this study. The hemodynamic change in the TCD was analyzed in terms of the demographic characteristics, the stroke risk factors, and the stenosis-related MRI abnormalities that are a proven risk factor of a further stroke. RESULTS: Fifty-three patients were retrospectively recruited. While there were no differences in the demographic characteristics or frequency of the stroke risk factors, the proportion of patients with stenosis-related MRI abnormality was significantly higher in patients with a hemodynamic change on TCD (13/19 vs 6/34, P < .01; odds ratio = 10.11; 95% confidence interval = 2.73-37.4). CONCLUSIONS: The TCD-detected hemodynamic changes may provide useful information for assessing the frequency of silent stroke in patients with an asymptomatic carotid stenosis.