Quantitative Doppler ultrasound evaluation of occlusive arterial disease in the lower limb

Forty consecutive patients with lower limb arterial disease were evaluated using a multi-gated pulsed Doppler system. Doppler signals were sampled at 4 sites in each limb, and following spectral analysis, the pulse rise time (PRT) was measured. The value obtained at the location giving the longest duration of PRT was used for comparison with ankle/brachial pressure index (A/B index) and angiography. A highly significant correlation was found between PRT and A/B index (r = -0.75, P less than 0.001). Based on receiver operating characteristic curves an overall diagnostic accuracy of 90% in diagnosing a pressure reduction greater than 20% was obtained. The diagnostic accuracy in detecting an angiographic stenosis greater than 50% was almost identical. Based on combined quantitative and qualitative analysis of Doppler signals sampled at the common femoral and popliteal artery, the aorto-iliac segments and the femoro-popliteal segments were evaluated separately. Comparison with arteriography revealed overall accuracies of 96% in the aorto-iliac segments and 87% in the femoro-popliteal segments. It is concluded that simple quantitatively measurable parameters in the Doppler spectrum may accurately predict and localize hemodynamically significant arterial lesions of the lower extremities.