Subclavian steals are caused by obstruction or stenosis in the subclavian artery or the brachiocephalic artery before the origin of the vertebral artery. Duplex ultrasonography is useful to detect the significant hemodynamic changes of the vertebral artery in the situation of subclavian steal, such as the changes of flow direction and waveforms. We report 2 cases of subclavian steal detected by duplex ultrasonography. Color-coded duplex ultrasonography appears to be an effective and sensitive method for detecting subclavian steal. Journal of Neurosonology 2(1):31-33, 2010

Key Words: Subclavian steal, Duplex ultrasonography, Vertebral artery