Ultrasonic doppler spectral broadening in the diagnosis of internal carotid artery stenosis

In a clinical study, 78 carotid bifurcations were examined by pulsed Doppler ultrasonography and X-ray arteriography. Maximum Doppler frequencies ⩾3 kHz diagnosed stenoses of ⩾25% diameter reduction with a sensitivity of 73% and specificity of 79%. A quantitative analysis of the degree of spectral broadening was obtained from the ratio of the maximum to mean frequency at peak systole and improved the sensitivity and specificity to 90% and 98% respectively. All vessels > 40% stenosis were correctly classified as stenosed and all > 20% stenosis were classified as normal.