Tumors of Renal Collecting Systems, Renal Pelvis, and Ureters: Role of MR Imaging and MR Urography Versus Computed Tomography Urography.

Hematuria evaluation remains a common problem, particularly in patients who smoke and are at risk for urothelial tumors. Lifetime surveillance of the urothelium is often required once urothelial cancer is diagnosed. Computed tomography urography (CTU) has exquisite sensitivity and specificity for identification of renal and urothelial lesions. The examination is well accepted by patients and physicians. Possible harms include radiation exposure and contrast-induced nephropathy. MR imaging is also an accurate test, but requires longer exam times, and may not demonstrate stones. We present the technical and interpretation skills required to use MR urography and CTU effectively.