The specific procedure may vary slightly depending on the reason for the test.

You will lie down on a scanner table. After cleaning the urinary opening, the health care provider will place a thin, flexible tube, called a catheter, through the urethra and into the bladder. A liquid with radioactive material flows into the bladder until the bladder is full or you say that your bladder feels full.

The scanner detects radioactivity to check your bladder and urinary tract. When the scan is to be done, depends on the suspected problem. You may be asked to urinate into a urinal, bedpan, or towels while being scanned.

To test for incomplete bladder emptying, images may be taken with the bladder full. Then you will be allowed to get up and urinate into the toilet and return to the scanner. Images are taken immediately after emptying the bladder.

There is no special preparation needed. You will need to sign a consent form. You will be asked to wear a hospital gown. Remove jewelry and metal objects before the scan.

You may feel some discomfort when the catheter is inserted. It may feel difficult or embarrassing to urinate while being observed. You cannot feel the radioisotope or the scanning.

After the scan, you may feel slight discomfort for 1 or 2 days when you urinate. The urine may be slightly pink. Call your provider if you have ongoing discomfort, a fever, or bright red urine.

This test is done to see how your bladder empties and fills. It can be used to check for urine reflux or a blockage in urine flow. It is most often done to evaluate people with urinary tract infections, particularly children.

A normal value is no reflux or other abnormal urine flow, and no obstruction to the flow of urine. The bladder empties completely.

Abnormal results may be due to:

• Abnormal bladder response to pressure. This could be due to a nerve problem or other disorder.
• Back flow of urine from the bladder into the ureters (vesicoureteric reflux)
• Blockage of the urethra (urethral obstruction). This is most commonly due to an enlarged prostate gland.

Risks are the same as for x-rays (radiation) and catheterization of the bladder.

There is a small amount of radiation exposure with any nuclear scan (it comes from the radioisotope, not the scanner). The exposure is less than with standard x-rays. The radiation is very mild. Nearly all the radiation is gone from your body in a short time. However, any radiation exposure is discouraged for women who are or might be pregnant.

Risks for catheterization include urinary tract infection and (rarely) damage to the urethra, bladder, or other nearby structures. There is also a risk of blood in the urine or burning sensation with urination.

Nuclear bladder scan

Elder JS. Vesicoureteral reflux. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 554.

Khoury AE, Wehbi E. Management strategies for vesicoureteral reflux. In: Partin AW, Domochowski RR, Kavoussi LR, Peters CA, eds. Campbell-Walsh-Wein Urology. 12th ed. Philadelphia, PA: Elsevier; 2021:chap 29.

Updated by: Kelly L. Stratton, MD, FACS, Associate Professor, Department of Urology, University of Oklahoma Health Sciences Center, Oklahoma City, OK. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.