Transcranial Doppler ultrasonography of the middle cerebral artery in the hemodynamic assessment of internal carotid artery stenosis
R. E. Kelley, R. A. Namon, S. H. Juang, S. C. Lee and J. Y. Chang
Department of Neurology, University of Miami School of Medicine, FL 33136.
We performed transcranial Doppler ultrasonography of the middle cerebral
arteries in 43 patients who underwent cerebral angiography. Twelve patients
had normal arteriograms, 18 had internal carotid artery stenosis, and 13
had complete occlusion. Parameters measured included: flow velocity (mean,
maximum, and peak systolic), flow acceleration, systolic-to-diastolic
ratio, and pulsatility index. Patients with 75% to 100% stenosis had lower
average ipsilateral flow acceleration and mean velocity than did normal
subjects. Correlation analysis revealed an inverse relationship between
degree of stenosis and ipsilateral flow acceleration, as well as
ipsilateral mean velocity. These correlations were no longer significant
when we excluded normals, however. There was a linear relationship between
right and left velocity values for both normal subjects and patients with
occlusion but not for patients with stenosis. This technique has potential
for the reliable assessment of the hemodynamic effect of carotid stenosis
on intracranial circulation.
