HF 7240

Nuclear Medicine Renal Scans, Renal Flow Scan, Diuretic (Lasix) Renal Scan

Test date____________________

Test time_____________________

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 and follow this to the atrium elevators. Go up to the 3rd floor and follow the signs to Radiology.

Renal Scan

A renal scan is a test that studies blood flow to the kidneys, and how the kidneys function. It can also look for blocked ureters. This is the pathway joining the kidneys to the bladder. The purpose is to look for issues that prevent urine from getting to the bladder.

You will be asked to empty your bladder right before the study. A staff person helping with your scan will help you lie down on an exam table. You will have an IV placed. When the scan starts, we will inject a small amount of a radioactive substance through the IV. We ask that you hold still and breathe normally during the scan. Allergic reactions are rare. A camera will take pictures of the radioactive substance as it moves through the kidneys, into your bladder.

After about 30 minutes, if ordered, we will inject the diuretic slowly through your IV and keep taking pictures for 20 more minutes. The diuretic will cause your bladder to fill quickly and increase your need to void. You will then be asked to void and collect urine for a measurement of volume. You will have more pictures taken for 5-10 minutes after voiding. The entire test will take between 1-2 hours.
Depending on your health history, you may need to have a urinary catheter inserted before the starting the scan.

Before the Test

Please tell your doctor if you are pregnant. This test should not be done if you are pregnant or breast-feeding, except under special cases. You will need to drink 2 eight-ounce glasses of water or juice 2 hours before the test.

After the Test

The test is painless. You may have minor pain when the IV is placed. The diuretic can give you an urgent need to go to the bathroom. The longer we can take pictures before you use the bathroom the better.


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. 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.