Real-time Doppler spectrum analysis: predictive value in defining operable carotid artery disease
R. W. Barnes, S. E. Rittgers and W. W. Putney
A prospective study compared the sensitivity, specificity, and predictive
value of indirect periorbital Doppler screening and direct carotid Doppler
interrogation using real-time sound spectrum analysis to detect operable
extracranial carotid occlusive disease. The results of noninvasive studies
were compared with independently assessed contrast arteriograms of carotid
arteries of patients studied for symptomatic cerebrovascular disease.
Periorbital Doppler ultrasound was insensitive to carotid stenosis of less
than 75% and did not distinguish operable stenosis from inoperable
occlusion of the internal carotid artery. Carotid Doppler spectrum analysis
was sensitive to 98% of hemodynamically significant disease and correctly
discriminated 77% of carotid occlusions, 96% of stenoses larger than 50%,
and 70% of stenoses of less than 50%. The predictive value for direct
carotid interrogation in identifying carotid occlusion or operable stenosis
was 94% and 86%, respectively. Real-time spectrum analysis of direct
carotid Doppler signals substantially improves the diagnostic accuracy of
noninvasive identification of operable carotid artery disease.
