Physiological interpretation of Doppler-shift waveforms--III. Clinical results.

Abstract The blood-velocity/time waveforms over the cardiac cycle obtained from the common femoral arteries of 44 limbs, are defined using Fourier transform and curve-fitting techniques. This results in a third order Laplace transform whose coefficients can be related to distal impedance, proximal lumen diameter and stiffness. The sensitivity of this technique has been investigated in the study of aorto-iliac disease, and compared with single plane arteriography and Pulsatility Index. The results show that the Laplace transform method is a sensitive technique for determining the presence of minor stenoses in the aorto-iliac segment, for determining changes in elastic modulus of the proximal vessels, and for studying changes in distal impedance. Pulsatility Index, is sensitive to the presence of proximal disease but it does not seem able to differentiate between stenoses of less than or greater than 50%. PI is sensitive also to changes in distal impedance, but insensitive to changes in arterial elasticity.