What Is a Kidney Scan?
A kidney scan is a test to check how your kidneys look and how well they’re working. Doctors also call it a renal scan, renal imaging, or renal scintigraphy.
Your doctor may recommend that you get this nuclear medicine scan because it offers information that other tests -- such as ultrasound, CT, and MRI -- can’t provide.
The test uses a small amount of radioactive material that’s inserted into your body. A special camera and computer detect traces of that material in your kidneys in order to make images.
Why Do I Need a Kidney Scan?
This test can help show how well each kidney is working, as well as problems that affect how both kidneys work, including:
How to Prepare for a Kidney Scan
Your doctor will let you know whether you need to drink extra fluids before your scan or whether your bladder should be empty.
Tell your doctor about any vitamins and supplements you take and whether you take aspirin, ibuprofen, or naproxen. These are a type of pain medicine called nonsteroidal anti-inflammatory drugs (NSAIDs).
Leave all jewelry at home. You may need to wear a gown during the scan.
Certain things can affect your test and make it less accurate. Let your doctor know if:
- You’ve had another test with radioactive material recently because you might still have some in your body.
- You’ve had a barium test recently because it might still be in your digestive tract.
- You take diuretics or medicine for your heart or high blood pressure.
- You’ve had an intravenous pyelogram test (a type of kidney X-ray that uses a contrast material) within the last 24 hours.
What Happens During a Kidney Scan?
To start the procedure, you’ll get an intravenous line (IV) in a vein in your hand or arm. The radioactive material, also called a tracer, will pass through the IV. You could have a metallic taste in your mouth briefly.
You may have to wait for the tracer to collect in your kidneys. When it’s time for the scan, you’ll either lie or sit on the scanning table. The camera might move around you, or you might have to change positions to allow images from different angles.
You may have to wait while the technician makes sure all the images are of good quality. It’s possible that you’ll have to repeat some positions to capture better images or additional views. If you do, it doesn’t necessarily mean your doctor saw anything bad on your scan.
Depending on the specifics of your test, your scan could take as little as 30 minutes or as long as 2 hours.
When the test is over, your IV comes out, and you’re ready to go home. The medical team may tell you to drink lots of fluids for 24 hours. Emptying your bladder often will flush the tracer from your system.
If you have any redness, pain, or swelling at the site of your IV, let your doctor know. You might have an infection or a reaction to the tracer.
Kidney Scan Risks
The amount of radioactive material used is small, so the risk is low.
A few people have allergic reactions.
You have to stay still during the test, and that’s uncomfortable for some people.
If you have any of these conditions or issues, let your doctor know in advance:
- You’re pregnant or might be pregnant. The scan could be unsafe for your baby.
- You’re breastfeeding. The radioactive material could taint your breast milk.
- You’re allergic to any medicines or sensitive to latex.
- You’re claustrophobic. The camera may move very close to you during the scan.
Kidney Scan Results
Your scan will go to a radiologist or other doctor trained to read the images. Then, a report will go to the doctor who ordered the test, and they’ll discuss the results with you.