A renal DTPA scan is a nuclear medicine exam in which a small amount of radioactive material (radioisotope) is used to measure the function of the kidneys, to see how the left and right kidney work comparatively. This test is also known as Renal DTPA Scan and Renal DMSA Scan. This test allows to visualize any sites of renal blockage. You must drink 1 liter of water in the 1 hours prior to your examination. You can go to the toilet as often as you need to. Please bring your prescription from the doctor, and previous medical records and relevant prior or recent scans/tests.