Answer to Question #1681 Submitted to "Ask the Experts"

Q

Which nuclides are typically used for intravenous pyelograms (IVPs) and what are the typical activities? Is the IVP the best imaging tool for renal imaging?

A

Actually, radionuclides are not used for IVPs. When an IVP is performed, a contrast agent is injected that isn't radioactive. The purpose of the agent is to cause the organs of interest to be "highlighted" on the films when x-ray images are taken. IVPs are most often performed to look for calcifications or stones that are preventing proper function of the kidneys or ureters, the tubes leading from the kidneys to the bladder, or because an individual has pain in the area of the kidneys. There are tests used in nuclear medicine that do use radionuclides to look at kidney or urinary system function. In these cases, a radiopharmaceutical is injected and, under a device called a gamma camera, the trained staff watches how the material is taken up and metabolized by the urinary system. The radionuclide is typically ^99mTc, and the activity is usually around 20 millicuries. We're lucky that physicians have many options available so the right type of exam can be performed for the patient. Depending on the patient's symptoms, an IVP might be the best tool. In other cases, perhaps a nuclear medicine test would be best. Kelly Classic Certified Medical Health Physicist