Detection of arterial stenosis: increased accuracy using biplanar angiography and Doppler signal analysis.

Femoral artery Doppler signals were analysed from 68 patients with lower limb ischaemia undergoing biplanar angiography. These studies (pulsatility index, P.I. and LaPlace transform damping, LTD) were compared with clinical examination using this biplanar angiographic standard. Accuracy of femoral pulse palpation in predicting upstream stenosis was 67%. Biplanar angiography unmasked single plane stenosis underestimates in 21% of patients. In a subgroup of 39 lower limbs with aorto-iliac stenoses between 26 and 85% femoral LTD was the best predictor, being 84% accurate: whereas PI did not improve upon clinical examination. The need for biplanar angiography is underlined and the place of Doppler signal analysis in the assessment of arterial stenosis is confirmed.