 During some operations, the operating physician must identify where the ureters are to prevent injury to them. Typically, the surgeon calls the urologist to thread a small scope with a camera into the urethra where the urine comes out to place a wire into each of the two ureters to locate them. Instead of this procedure, we will inject a small amount of a radioactive chemical dye TC99-DTPAthrough a vein in your arm. The ureters can then be detected by a hand held probe called the gamma probe. The TC99-DTPA dye passes through the body and is excreted through the urine. The goal of this study is that this probe will alert the physician when it placed directly over the ureters since the TC99-DTPA dye will highlight the ureters as the flow of urine goes through them. 