Subclavian steal syndrome: diagnosis with perfusion metrics from contrast-enhanced MR angiographic bolus-timing examination--initial experience.

PURPOSE: To retrospectively determine whether differential temporal changes in signal intensity of the vertebral arteries, measured at a bolus-timing examination with a test dose of a gadolinium-based contrast agent, are present in patients with subclavian steal syndrome. MATERIALS AND METHODS: Institutional review board exemption was obtained, and informed consent was not required for this retrospective study. The study complied with the Health Insurance Portability and Accountability Act. Twenty-five patients with known or clinically suspected atherosclerotic disease of the aortic arch and branch vessels underwent breath-hold contrast material–enhanced magnetic resonance (MR) angiography with circulation time derived from a timing examination by using a test bolus of a gadolinium-based contrast agent. Eight patients (three men and five women aged 54–80 years; mean, 70 years) had subclavian stenosis or occlusion with retrograde vertebral artery flow confirmed with time-of-flight MR angiography, nine pati...