[Duplex sonographic determination of blood pressure gradient in iliac artery stenoses. Comparison with invasive measurement].

The present study investigates the validity and accuracy of the simplified Bernoulli equation in the duplex-derived determination of pressure gradients across iliac artery stenoses. 28 patients presenting with iliac artery stenoses were examined by both duplex scanning and intraarterial catheter pressure measurement. The catheter-determined and duplex-derived mean pressure gradient was 16 +/- 7 and 14 +/- 7 mmHg, respectively. There was a fairly good correlation between the mean pressure gradients assessed nonsimultaneously by both methods (r = 0.77). The catheter-determined and duplex-derived maximum instantaneous pressure gradient was 53 +/- 16 and 52 +/- 21 mmHg, respectively. The correlation coefficient (r) for the maximum instantaneous pressure drop values determined by the two methods was r = 0.79. The results show that duplex ultrasound predicts mean and maximal-instantaneous pressure gradients with acceptable approximation in patients with iliac artery stenoses.