Renal MR angiography: a comprehensive approach.

Renal artery MR angiography has now emerged as a safe, accurate approach to renal arteriography. A comprehensive examination, including both three-dimensional (3D) dynamic gadolinium-enhanced and 3D phase contrast MRA techniques, allows evaluation of both the aorta-renal and splanchnic arterial anatomy as well as the hemodynamic significance of any stenoses identified. The 3D gadolinium-enhanced MRA technique produces a contrast arteriogram but without risks of iodinated contrast or ionizing radiation. The 3D phase contrast technique is a flow-based technique, which may show dephasing in the presence of hemodynamically significant stenoses. A comprehensive examination should also include T1- and T2-weighted imaging for the assessment of potential neoplastic masses and the ubiquitous renal cysts. Through trial and error over the course of over a thousand examinations, this comprehensive approach to the MR evaluation of renal vascular pathology has emerged.