Renal Artery Contrast-Free Trial

REACT is a prospective, minimal-risk, and multi-center international trial. The purpose of the study is to evaluate the safety and efficacy of non-contrast magnetic resonance angiography (MRA) for the diagnosis of renal artery stenosis (RAS). The current "gold standards" for diagnosing RAS are non-invasive 3D angiography with contrast-enhanced CTA/MRA or invasive X-ray angiography. All of these techniques require the use of an intravenous injection of either iodinated contrast material or gadolinium based agents. Iodinated contrast agents are contraindicated in patients with renal dysfunction and have increased risk of allergic reaction. Contrast-enhanced magnetic resonance angiography (MRA) with gadolinium has fewer risks associated with it, however, is currently contraindicated in patients with severe renal insufficiency because of concerns about developing a rare but often fatal condition termed nephrogenic systemic fibrosis (NSF). Non-contrast MRA techniques are felt to provide an avenue for safer, effective vascular imaging in patients both with and without kidney dysfunction. In this trial we propose to validate the contrast-free MRA technique, T-SLIP (time-spatial labeling inversion pulse), for diagnosing RAS. This study will compare T-SLIP to the reference standard of contrast-enhanced CTA and is designed to test its efficacy, reproducibility, reliability, and safety.