Doppler ultrasound in the diagnosis of the popliteal artery entrapment syndrome.

Doppler pulse recordings in a patient with asymptomatic popliteal entrapment were compared with those in 25 normal subjects. A drop in pulse amplitude and ankle systolic pressure produced by forcible leg extension and active foot plantar flexion distinguished the patient with the anomaly from the controls, in whom no change was noted during these manoeuvres. This simple, non-invasive test thus diagnosed a potentially limb-threatening congenital abnormality in an asymptomatic patient with equivocal arteriographic findings.