Renal MR angiography.

Three-dimensional gadolinium MR angiography (3D-Gd-MRA) accurately visualizes the renal arteries with almost no degradation from inplane saturation or motion artifacts. The diagnostic accuracy for detecting and grading of renal artery stenosis, as well as the assessment of other vascular pathology, approaches that of conventional x-ray angiography. For the renovascular system, this technique requires precise contrast media bolus timing since multiple successively enhancing structures are present. Details on performing renal MR angiography, strategies for image analysis, and examples of common renal vascular pathology are reviewed. The 3D-Gd-MRA protocol can be easily combined with other MR imaging techniques to provide a comprehensive assessment of the hemodynamic and functional significance of renal artery stenosis.