Duplex velocity characteristics of aortoiliac stenoses.

PURPOSE: It is now possible to grade aortoiliac stenoses in broad categories based on peak systolic velocity (PSV) changes. The goal of this study was to see whether additional simple Doppler parameters would improve the grading of aortoiliac obstructive disease. METHODS: Duplex parameters were compared in 112 aortoiliac segments with four categories of arteriographic diameter reduction and four categories of common femoral artery pressure measurements. These parameters were PSV, PSV ratio, PSV difference, end diastolic velocity (EDV), the presence or absence of reverse flow, and the presence or absence of spectral broadening. RESULTS: The discriminative value of the PSV ratio was better than that of either the absolute PSV value or the PSV difference. A PSV ratio < 1.5 combined with reverse flow and a clear systolic window in the Doppler spectrum predicted a diameter reduction < 20% (sensitivity, 100%; specificity, 58%; positive predictive value [PPV], 89%; negative predictive value [NPV], 100%; accuracy, 90%). For the detection of > or = 50% aortoiliac stenoses, a PSV ratio > or = 2.8 provided 86% sensitivity and 84% specificity (PPV, 84%; NPV, 85%, accuracy, 85%). An absolute PSV value of 200 cm/sec has a high sensitivity (95%) but a low specificity (55%) in identifying > or = 50% stenoses (PPV, 68%; NPV, 91%; accuracy 75%). An EDV > 0 cm/sec at the stenosis indicates a femorobrachial pressure index < 0.90 with 51% sensitivity and 89% specificity. An EDV > or = 40 cm/sec indicates a femorobrachial index < 0.80 with 50% sensitivity and 89% specificity, and indicates > or = 75% arteriographic stenoses with 70% sensitivity and 90% specificity (PPV, 64%; NPV, 92%; accuracy, 86%). A stenosis > or = 75% was also identified by a PSV ratio of 5.0 with 65% sensitivity and 91% specificity (PPV, 65%; NPV, 91%; accuracy, 86%). CONCLUSIONS: The PSV ratio is the most important parameter to grade aortoiliac stenoses into < 20%, 20% to 49%, 50% to 74%, and 75% to 99% categories, but additional parameters such as absolute PSV value, EDV, and the presence or absence of reverse flow and spectral broadening in the Doppler spectrum are helpful in gradation.

Photoplethysmography in the diagnosis of superficial venous valvular incompetence.

Photoplethysmography was compared with clinical investigation combined with Doppler ultrasonography in the diagnosis of superficial venous valvular incompetence of the lower limb. In 268 consecutive patients, 536 limbs were investigated. A total of 22.1 per cent of the photoplethysmographic investigations were uninterpretable because they did not allow reliable determination of the refilling time. Agreement between clinical investigation combined with Doppler ultrasonography and photoplethysmography was found to be poor (kappa = 0.30). These results suggest that photoplethysmography is not the non-invasive method of choice for routine evaluation of superficial venous valvular incompetence of the leg.