Duplex Doppler ultrasonography of subclavian steal syndrome--three case reports.

Three cases of subclavian steal syndrome were detected by duplex Doppler ultrasonography. Ultrasonography demonstrated retrograde flow with to-and-fro pattern in the right vertebral artery in two cases, and reflux with diastolic flow deceleration in one case. Interventional treatment with stenting was successfully performed in two cases and conservative treatment was given in one case. Ultrasonography is an effective noninvasive method for the evaluation of the vertebral artery, and should become a routine part of cerebrovascular examinations.