A cystourethrogram is an X-ray test that takes pictures of your bladder and urethra while you are urinating. A thin flexible tube (catheter) is inserted through your urethra into your bladder. A liquid material that shows up well on an X-ray picture (contrast material) is injected into your bladder through the catheter, then X-rays are taken with the contrast material in your bladder. Additional X-rays may be taken while urine flows out of your bladder, in which case the test is called a voiding cystourethrogram (VCUG).

If X-rays are taken while contrast material is being injected into the urethra, the test is called retrograde urethrogram because the contrast material flows into the bladder opposite the usual direction of urine flow.

Why It Is Done

A cystourethrogram is done to:

• Find the cause of repeated urinary tract infections.
• Look for injuries to the bladder or urethra.
• Find the cause of urinary incontinence.
• Check for structural problems of the bladder and urethra.
• Look for enlargement (hypertrophy) of the prostate or narrowing (stricture) of the urethra in men.
• Find out if urinary reflux is present. See an illustration of abnormal backflow of urine.
• Look more carefully at abnormalities first found by intravenous pyelography.

How To Prepare

Tell your doctor if:

• You are or might be pregnant.
• You have symptoms of a urinary tract infection.
• You are allergic to the iodine dye used in the contrast material or any other substance that contains iodine. Also tell your doctor if you have asthma, are allergic to any medicines, or have ever had a serious allergic reaction (anaphylaxis), such as after being stung by a bee or from eating shellfish.
• Within the past 4 days, you have had an X-ray test using barium contrast material, such as a barium enema, or have taken a medicine (such as Pepto-Bismol) that contains bismuth. Barium and bismuth can interfere with test results.
• You have an intrauterine device (IUD) in place.

You may be asked to sign a consent form authorizing this procedure. Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results may mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).

If you are breast-feeding, give your baby formula for 1 to 2 days after the test.

How It Is Done

A cystourethrogram is done by a urologist or a radiologist. The doctor may be assisted by an X-ray technologist. You usually will not have to be admitted to the hospital.

You will need to take off all or most of your clothes, and you will be given a cloth or paper covering to use during the test. You will be asked to urinate just before the test begins.