Non-contrast-enhanced MR angiography of the abdomen

Non-contrast-enhanced magnetic resonance angiography (MRA) techniques have experienced a resurgence of interest in the MR community, in part because of safety concerns related to the possible link between gadolinium-based contrast agents and nephrogenic systemic fibrosis (NSF). In abdominal MRA, NSF is of particular concern, given that many of the patients may have renal disease. After introducing various non-contrast-enhanced MRA techniques, this article focuses on MRA applications in the abdomen, specifically the renal arteries and portal and hepatic veins. Developments on the horizon are discussed, including techniques that provide standardization of renal artery imaging, challenges in imaging of the hepatic arteries, and further advancement at 3 T.