Application of Color Doppler Flow Imaging in Diagnosis of Subclavian Steal Syndrome

Objective To analyze the hemodynamics and spectral characteristics of the subclavian, vertebral and radialis artery, and the relationship between the severity of stenosis and the steal degree in 11 patients with subclavian steal syndrome (SSS) by color Doppler flow imaging (CDFI). Methods Eleven patients were diagnosed as SSS by clinic, CDFI and related physical examinations. The inside diameter and intima-media of carotid, vertebral, radialis, subclavian and innominate arteries were displayed with two-dimensional ultrasonography, and their blood flow velocity and direction were detected by CDFI. Results In the 11 patients with SSS, 7 patients had subclavian arterial stenosis with the inside diameter 1.0~4.4 mm and the velocity 100~420 cm/s. Occlusion of subclavian or innominate arterries occurred in 4 patients and caused a full SSS. The peak flow velocity of ipsilateral vertebral and radialis artery decreased significantly compared with the contralateral vertebral and radialis artery, and retrograde vertebral flow was also detected. There was a obviously relation between radialis artery flow and the severity of subclavian arterial stenosis as well as reverse vertebral flow in SSS. Conclusion The full SSS could be diagnosed by CDFI. Combining the CDFI and pulsed Doppler with tourniquet test, the partial SSS could be diagnosed. The full or partial SSS was dependent on the severity of stenosis. The peak flow of ipsilateral vertebral artery and raddialis artery was determined by cullateral circulation.