Health Library
Lasix Renal Scan

What is a Lasix Renal Study?

What is nuclear medicine?

Nuclear medicine in a specific area of radiology. It uses small amounts of radioactive medicine to look at different parts of the body with a special camera. The pictures from the camera show how your body is working. The camera doesn’t give off radiation like an X-ray. Parents and caregivers who are pregnant can safely be with the patient during and after the test.

What is a Lasix renal study?

A Lasix renal study is a test that shows how well the kidneys are working. It also shows if there is anything blocking the urinary system. Pictures of the urinary system (kidneys, ureters or tubes connecting the kidneys to the bladder and bladder) are taken after a special medicine is put into the veins. An intravenous (IV) line is used to put the medicine into the body. The IV is a small, soft, flexible tube that goes in the vein under the skin.

After the test, a measurement will be done on the computer comparing the amount of kidney function in the right and left kidneys.

Sometimes children have a tough time staying still for this test, so anesthesia (sleepy air) may be used. Instructions are below for a test both with and without anesthesia.

Before the Test

Without anesthesia

Before coming to the hospital, read the explanation about the test below. Explain to your child what will happen during the test.

If your child is an infant, it is helpful to bring along a bottle of formula or juice for after the test. It is also recommended that you bring a pacifier, blanket or special toy to help calm your child.

For older children, it is helpful to bring a book or toy so that they can play while waiting.

The day of the test, you should get to the hospital 15 minutes before your child’s appointment. Your child can keep taking all medicines that they normally do.

The test will last about two hours.

Your child should not drink fluids with caffeine in them (soft drinks, tea or coffee) on the day of the test.

It is helpful to have another caregiver watch your child's siblings. If you need to change or cancel your child’s appointment, call 513-636-3200.

With anesthesia

You will get a phone call from a nurse about 48 hours before your child’s test. She will ask questions about your child’s health. She will also give you information about eating and drinking before the test. If you don’t get this phone call, call 513-636-4251, option 5 between 6:30am and 8:30pm Monday through Friday.

If your child is sick with congestion, cough or fever the day before the test, call 513-636-6392 to let us know. We may need to reschedule your child’s test.

The day of the test: Eating and drinking instructions for children less than 12 months old:

Six hours before getting to the hospital: no food, milk products, juices that you can’t see through, broth, thickened liquids, candy or gum

Your child may have clear liquids. These are fluids that you can see through. Examples are water, clear drinks, pulp-free juice, popsicles, Pedialyte and Jell-O.

Four hours before getting to the hospital: no breastfeeding

Two hours before getting to the hospital: Nothing else to drink. No clear liquids.

The day of the test: Eating and drinking instructions for children 12 months of age or older

Eight hours before getting to the hospital: no food, milk products, juices you can’t see through, broth, thickened liquids, candy or gum.

Your child may have clear liquids. These are fluids that you can see through. Examples are water, clear drinks, pulp-free juices, popsicles, Pedialyte and Jell-O.

Four hours before getting to the hospital: no breastfeeding

Two hours before getting to the hospital: Nothing else to drink. No clear liquids. Watch tooth brushing to be sure your child doesn’t drink.

Arrive at least one hour before your child’s appointment time. A parent or legal guardian must come with the child. Normal medications can be taken with a sip of water or a teaspoon of Jell-O. You will be at the hospital for three hours for this test. If you need to change or cancel your child’s appointment, call 513-636-3200.

During the Test

A technologist will place a small needle into your child's hand or foot. This is called an IV. The technologist will also place a small tube, or catheter, into the bladder through the opening where urine comes out. It will hurt for a moment when the needle and the catheter are placed. A parent or caregiver can stay with the patient during the test if they are not getting anesthesia.

After the needle and catheter are in place, the special medicine is injected into the IV. Your child will then lie on a soft table while pictures are taken with a special camera that is located below them. This picture session lasts about 20 minutes. During this time, your child will have fluids going through the IV.

Next your child may be given a medicine called Lasix through the same IV line. The same kind of pictures will be taken for 30 more minutes. Some children do not need the Lasix to finish the test.

Your child will need to be still while the IV and catheter are placed and while the pictures are taken. It is often difficult for young children to lie still at this time. If your child is unable to lie still, our staff will assist your child in holding still. Parents may stay with their child during the entire test.

It is possible that during the procedure your child may experience some discomfort. Please tell the doctor, nurse or technologist if pain occurs.

After the Test

The technologist will tell you when all of the pictures have been taken. The needle and catheter will be removed. Your child may return to normal daily activities. After having the urinary catheter placed for the test, your child's urine may be pink the first time they pee. This is caused by a small amount of blood in the urine. Your child may also have some discomfort peeing after the catheter is removed. Drinking more fluids will help this feel better. If your child’s pee is pink for more than 24 hours or if your child has difficulty peeing, call your child's doctor.

Your child will get rid of the medicine from their body when they pee. It should be completely out of your child's body within six to eight hours. As always, after your child pees, you and your child should wash your hands. Wash your hands after handling diapers or urine-soaked sheets.

Results of the test will be available to your child's doctor within 24 hours. They will contact you about the results.

Last Updated 06/2022

Reviewed By Joby MacLean
Meet the team.

Radiology and Medical Imaging is home to specialists with a wide variety of backgrounds and areas of focus. 

Contact us.