Notice
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Location
This test is done at University Hospital in the Nuclear Medicine section of Radiology. Go in the clinic entrance. Go right on Main Street to Atrium Way. Follow this to the atrium elevators. Go up to the 3rd floor and follow the signs to Radiology.
GFR Test
A nuclear medicine GFR test will assess the overall function of the kidneys. It measures how quickly they filter out a radioactive tracer from your bloodstream. The test does not tell us differences between the left or right kidney function.
A Nuclear Medicine Technologist will insert an IV in your arm or hand. A radiotracer will be injected into the IV. The injection does not have any side effects. Blood samples will be drawn at 1 and 3 hours. After the 3-hour blood draw, the IV will be removed and you are done with the test. The samples are taken to our lab to be processed. Results will show how much radioactivity was filtered by the kidneys.
Preparing for the Test
You should not have any caffeine after 10pm the night before the test. The morning of the test, you may eat a light breakfast, but the breakfast should be low in protein. You will need to stay on a low protein/no caffeine diet until the end of the procedure. Please drink 32 ounces of clear liquid (water, apple juice, etc.) 1 hour before the test. If you are pregnant or breastfeeding, please contact your doctor for guidance.
During the Test
After getting the radiotracer injected, please stay in the waiting area until the 1-hour blood draw is done. After that, you are free to walk around, but please be on time for the 3-hour blood draw.
After the Test
The test is painless. You may have minor discomfort when the IV is placed. There are no restrictions after the test.
Risks
Many people worry when they hear that the substance used in this test is radioactive. The amount used is so small that there should be no side effects. This test is very safe. There is a very small amount of radioactivity used in this exam that will be excreted from your body within a day or two. You should tell your doctor if you are pregnant or breast-feeding before you have this test.
Who to Call
University Hospital Radiology, Monday-Friday, 8 am-4:30 pm, (608) 263-9729.
The toll-free number is 1-800-323-8942. Ask for Radiology.