Advances in contrast-enhanced MR angiography of the renal arteries.

Renal artery stenosis (RAS) is a potentially curable cause of renovascular hypertension (RVH) and is caused by either atherosclerosis or fibromuscular dysplasia in the vast majority of patients. Although intra-arterial digital subtraction angiography is still considered the standard of reference test for the anatomic diagnosis of RAS, MR angiography and functional renal MR imaging are promising alternatives that also allow for functional characterization of RAS. This article provides an overview of these techniques and discusses their relative merits and shortcomings. Because missing RVH may have serious consequences the most important requirement for an alternative test is that it has high sensitivity. An unresolved issue is the prediction of functional recovery after therapy.