Carotid ultrasonic arteriography combined with real time spectral analysis: a comparison with angiography

In a one year period, 400 patients were examined by carotid ultrasonic arteriography combined with real time sound spectral analysis. Contrast arteriography was performed on 112 patients. The noninvasive examinations and contrast arteriograms of these patients were reviewed by two independent observers, who were unaware of the findings of the other diagnostic modality. There were 190 vessels available for comparison. The internal carotid artery was classified as normal, less than 50% stenosis, greater than or equal to 50% stenosis, or occluded. The specificity of these non-invasive tests was 79%. The sensitivity in correctly identifying stenoses as less than 50% or greater than or equal to 50 was 85% and 91% respectively. The sensitivity in identifying occluded vessels was 90%. The positive and negative predictive values were 87% and 92% respectively. Noninvasive evaluation correctly identified six lesions misdiagnosed by arteriography. We found pulsed Doppler arteriography combined with real time spectral analysis to be an accurate, direct, noninvasive method of assessing the extracranial carotid arteries.