Magnetic resonance angiography and detection of renal artery stenosis in a patient with impaired renal function.

Diagnosing renovascular disease in patients with renal insufficiency has challenged physicians for many years. Although contrast angiography is the "gold standard," it is associated with major risks in patients with preexisting renal failure. Other noninvasive tests have not proved to have sufficient sensitivity and specificity to supplant angiography. Developments in magnetic resonance (MR) angiographic technology, however, now enable physicians to assess the vasculature noninvasively and without use of potentially nephrotoxic agents. Herein we describe a patient with hypertension and renal failure in whom MR angiography proved to be the only effective noninvasive test for diagnosing renal artery stenosis. In addition, we review the current literature on MR angiography for renovascular disease. In the setting of renal impairment, MR angiography may be useful in screening patients for renovascular disease. More studies are needed in order to refine MR angiographic techniques and, ultimately, to determine specific situations in which MR angiography may be useful.