Doppler waveform analysis in the management of lower limb arterial disease

Arterial disease changes the shape of Doppler ultrasound waveforms recorded noninvasively from arteries in the lower limbs. These changes can be described numerically by computer analysis of waveforms, and techniques currently in use are pulsatility index, Laplace transform and principal component analysis. These waveform analysis methods allow assessment of aortoiliac disease from Doppler recordings at the femoral artery. In addition, the femorodistal segment can be evaluated by comparing femoral and distal waveforms, even in the presence of more proximal arterial disease. Other possible applications for waveform analysis include noninvasive follow-up of angioplasty or bypass grafts and the detection of early, presymptomatic arterial disease. Experience in recording Doppler waveforms is important if variability is to be minimised. Currently, these methods allow exclusion of aortoiliac disease prior to femorodistal grafting but their other potential roles require further clinical evaluation.