What is a VCUG?

A VCUG, or a voiding cystourethrogram, is a procedure that allows a radiologist (imaging doctor) to see how the urinary system (system that produces urine) works. Using a special x-ray called fluoroscopy and contrast fluid (dye), a radiologist will examine the bladder and the lower urinary tract while your child voids (urinates). This contrast fluid will allow the radiologist to see the urinary system. Most cystourethrograms take about 30 minutes, but this can vary with each child.

Why does my child need a VCUG?

Your child’s doctor might order this procedure if your child has had a urinary tract infection (UTI) or if your child has other problems related to their urinary tract. A VCUG can help doctors check for diagnose a condition known as vesicoureteral reflux (when urine moves backward from the bladder into the ureters, or tubes that connect the kidneys to the bladder, and possibly the kidneys). This can allow bacteria to reach the kidneys and cause damage to the kidneys. Not all children who have UTIs or bladder infections have reflux.

Who performs the examination?

A pediatric radiologist and a pediatric-trained x-ray technologist (person who takes pictures for imaging tests) will help you and your child during this procedure. At times, a child life specialist will also be present during your child’s procedure. A child life specialist helps your child cope with their hospital experience through age-appropriate play, distraction and explanations.

How is the VCUG performed?

  1. A pediatric x-ray technologist or a child life specialist will bring you and your child into the fluoroscopy room. They will also explain the procedure to you and your child.
  2. Your child will change into a hospital gown. Once changed, your child will be helped onto the fluoroscopy table.
  3. The technologist will then clean the opening of your child’s urethra (where urine exists the body) with a brown soap called betadine. This soap will remove any germs that could cause an infection.
  4. The technologist will apply a numbing gel called lidocaine to your child’s urethra. Then, they will insert a small tube called a catheter through your child’s urethra until it reaches their bladder. The catheter will be gently taped in place.
  5. The technologist will connect the catheter to a bottle of contrast fluid. The contrast fluid will flow into your child’s bladder through the catheter. As the bladder is filled, a pediatric radiologist will take x- rays.
  6. Your child will eventually start to feel a strong urge to void. The radiologist will roll your child onto each of their sides and remove the tape holding the catheter in place. When your child’s bladder is full, they will be asked to void onto towels or into a bed pan. While your child voids, the catheter will flow out.
  7. If your child is not toilet trained, the radiologist send contrast through the catheter about 3 times. This means your child’s bladder will be filled with contrast fluid 3 times and your child will void 3 times. Doing this helps make sure the radiologist gets the most accurate information and images.
  8. Once your child has voided, the radiologist will take additional x-rays and help your child get cleaned up. Then, the procedure is done.

How can I prepare my child for the VCUG?

Your child’s age will determine how you will prepare them. Above all, it is important to be completely honest with your child about the procedure.

  • Toddlers and preschool-aged children require a very simple explanation of the procedure just before the procedure begins.
  • School-aged children and adolescents (teens and young adults) require a more detailed explanation of the procedure, which should be done 1-2 days before the procedure. This will allow your child time to ask any questions they might have before the procedure.

What will my child feel during the VCUG?

  • Your child will feel cool, wet soap used to clean their genital area.
  • Your child will also feel some pressure and discomfort when the catheter is inserted. Many children also feel the urge to urinate when the catheter is inserted. Both sensations should pass once the catheter is in place. Many children describe the catheter as uncomfortable and annoying.
  • As your child’s bladder fills with the contrast fluid, they will feel the urge to void. Before voiding, the technologist will remove the tape holding this catheter. This can sometimes feel like a Band-Aid®. Your child may or may not feel the catheter come out when they void.

What can I do to help my child during the procedure?

You will be present during your child’s entire procedure.* For some children, having a family member with them is comforting enough. Others may require additional support.

The radiology team has toys, books and other distraction items that can help your child during the procedure.

*People who are pregnant will not be allowed in the fluoroscopy room. (Please note that other children will not be allowed in the fluoroscopy room.)

What happens once the VCUG is done?

The results of your child’s procedure will be sent to the doctor who requested the procedure. Typically, your doctor will receive the results within 1-2 days of the procedure or sooner. Urgent results are communicated to the ordering doctor shortly after the procedure has been completed.


If you have additional questions or concerns regarding the VCUG, please contact the Pediatric Imaging child life specialist at 617-724-1153.

Rev. 6/2017. This document is intended to provide health related information so that you may be better informed. It is not a substitute for a doctor's medical advice and should not be relied upon for treatment for specific medical conditions.