Functional renal MR imaging.

MR imaging is the only noninvasive test that may provide a complete picture of renal status with minimal risk to the patient, simultaneously improving diagnosis and lowering costs. This article reviews several MR renography techniques, including approaches for quantifying renal perfusion and glomerular filtration rate. Also discussed are clinical applications for the diagnosis and follow-up of renovascular disease, hydronephrosis,and renal transplant dysfunction. The article concludes with an overview of technical problems and challenges facing MR renography.