The assessment of carotid and vertebral arteries: a comparison of CFM duplex ultrasound with intravenous digital subtraction angiography.

The use of duplex ultrasound with colour flow mapping is compared with that of intravenous digital subtraction angiography (IVDSA) in the investigation of carotid and vertebral artery disease. Ninety-nine carotid and vertebral arteries were examined independently by IVDSA and ultrasound for location and degree of disease in 30 men (mean age 58) and 20 women (mean age 53). For purposes of comparison the carotid tree was divided into six segments. In 46% of cases no disease was detected by either modality. In 36% of cases where disease was found, ultrasound found mild disease in arteries reported as normal by IVDSA. Both modalities detected the six cases of total occlusion found in the study. IVDSA underestimated five cases of major disease found by ultrasound at the bifurcation or in the bulb. Overall agreement in grading vessel segments was good, with 74.5% in complete agreement and 90.3% grading stenoses to within +/- 25% of the other modality. There was good qualitative agreement in the findings for vertebral arteries. In four patients conventional arteriography was also available for comparison.