Diagnostic performance of the bidirectional Doppler velocity curve recorded at the ankle

The diagnostic value of different parameters derived from the Doppler velocity curve recorded at the ankle was analysed in a population of 432 subjects. To document the presence or absence of obliterative arterial diseases in the lower limbs, systolic blood pressure measurements were made and oscillography before and after exercise was recorded. A descending slope below 20.5 mm as recorded during 0.40 sec, appears as a sensitive indicator of occlusive arterial diseases of the lower extremities: 84% of the limbs were correctly classified showing with a high sensitivity of 91.8% but a lower specificity of 76%. By considering a combination of two parameters (descending slope and crest-time), the overall performance increases up to 88% and specificity becomes satisfactory (85%), while sensitivity is kept at 90%. Quantitative analysis of the Doppler velocity curve recorded at the ankle is feasible and is most helpful in discriminating normal and abnormal limbs both in daily clinical practice and in large scale studies.