Journal of Ultrasound in Medicine, Vol 16, Issue 3 213-218, Copyright © 1997 by American Institute of Ultrasound in Medicine
Detection of vertebrobasilar intracranial stenoses: transcranial Doppler sonography versus angiography
J. M. de Bray, A. Missoum, F. Dubas, J. Emile and P. Lhoste
Laboratory for Vascular Exploration, University Hospital, Angers, France.
Vertebrobasilar intracranial stenoses seem to carry a higher risk of brain
stem ischemia than proximal vertebral artery stenoses. Our aim was to
assess the value of transcranial Doppler sonography versus angiography in
detecting and quantifying these intracranial stenoses. All consecutive
patients who underwent transcranial Doppler sonography prior to angiography
from 1989 to 1994 and whose sonograms showed a stenosis of greater than 50%
of one vertebral artery (21 cases) or of the basilar artery (eight cases)
were included in the study. These patients were compared with 60 other
consecutive stroke patients studied via transcranial Doppler sonography
prior to normal vertebrobasilar angiography The transcranial Doppler
sonographic criteria for stenosis were a peak systolic frequency shift
greater than 2 KHz. A tight stenosis was identified by this pattern
combined with direct and reverse low frequencies of high spectrum energy.
The sensitivity of transcranial Doppler sonography using a peak systolic
frequency shift in diagnosing stenoses reached 80% and its specificity was
97% if only atheromatous stenoses were considered. The main diagnostic
failures concerned bilateral stenoses or contralateral occlusion, tandem
lesions, and upper basilar artery stenosis. Transcranial Doppler sonography
underestimated the degree of stenosis compared to angiography in 55% of the
cases. We conclude that transcranial Doppler sonography is accurate in
recognizing a stenosed vessel in the intracranial vertebrobasilar
circulation, but if this finding will alter therapy, the examination must
be complemented by magnetic resonance angiography.
