Voiding Cystourethrogram

During your journey toward a diagnosis, your pediatric urologist or nephrologist may request that your child undergo a voiding cystourethrogram or VCUG.

What is a VCUG or Voiding Cystourethrogram and what is it used for?

“Voiding” means that part of the study is done with the patient peeing, and “Cystourethrogram” means that the study is done to know more about the anatomy of the bladder (“cysto”) and urethra (“uretho”).

It can give a lot of information about your child’s urinary tract. It is most often requested in the following conditions:

Repeated infections of the urinary tract
Known or suspected problems of the spine that can affect the bladder
Suspected abnormal connections between the urinary tract and other parts of the body, like the urethra or vagina
Suspected blockages in the urinary tract, including inborn abnormalities like “Posterior urethral valves” or acquired issues like a stricture or narrowing of the urethra

It is most commonly used to diagnose “vesicoureteral reflux” (VUR) in children with repeated infections of the urinary tract. Click here for more information about VUR.

How is a VCUG done?

First things first:

The VCUG is often done inside the x-ray department or in special rooms with an x-ray machine.

It is often done by a urologist, radiologist, and/or radiology technician.

Since the VCUG is usually done without general anesthesia, there is usually no fasting period beforehand.

A child’s parents may be present during all or part of the procedure, but will be asked to wear special outfits with built-in lead to decrease radiation exposure.

A child is asked to lie on the table, and a baseline x-ray film is taken that looks at the abdomen.

Then, a sterile urinary catheter is inserted gently into the urethra, with the aid of a lidocaine jelly (which helps with both lubrication and partially numbing the area temporarily). (Some patients already have the catheter inserted prior to the VCUG for other medical reasons.)

In boys, this insertion is through the opening of the penis. In girls, the urethral opening is found close to the vaginal cavity.

The provider will empty out any urine in the bladder.

Filling phase

Afterwards, a certain amount of diluted dye will be gently instilled into the bladder. The amount that is instilled is computed so as not to excessively fill the bladder.

During this process or the “filling phase”, the catheter stays in the bladder. As the dye fills up the bladder, the radiologist or urologist will look at the following:

The contour or shape of the bladder when filling
If there is presence of “reflux” or urine shooting up into the ureters or kidneys
The capacity of the bladder, or its ability to stay filled without leaking

At some point, the filling of the bladder will stop. This is usually when:

The computed capacity of the bladder has been reached
The child is already uncomfortable and unable to stop from voiding or leaking
There is involuntary leaking that is starting to exceed the rate at which the bladder is being filled

A normal, filled bladder on VCUG.

There is a good, smooth contour, and no reflux is seen shooting up into the ureters or kidneys.

Image source here.

Voiding phase

The next phase starts when the child starts to pee, or when a lot of urine leaks involuntarily.

Most of the time, the catheter may fortunately be removed at this point.

At this point, the radiologist or urologist will look at the following:

The contour or shape of the bladder when peeing
If there is presence of “reflux” or urine shooting up into the ureters or kidneys during peeing
The shape of the urethra, and the presence of abnormal connections or blockages
If any dye or contrast is left in the bladder, the kidneys, or ureters after peeing

Sometimes, it may become necessary to repeat the test, or to do another cycle of filling and voiding.

A child with severe vesicoureteral reflux (VUR).

Contrast is seen going up into the ureters and kidneys.

Image source here.

“Can my child undergo the VCUG while asleep? I don’t want them to be traumatized.”

Ideally, the VCUG is done awake, because we usually need patients to be awake to pee properly.

Putting in the catheter may be the most difficult part of the procedure for children. You and your provider should take about the risks and benefits of providing anesthesia at this point. If the benefit of anesthesia exceeds the risks, you may both agree on a gentle sedation to help the child be asleep for the catheter insertion.

However, most times, the patient will be woken up prior to filling up the bladder and checking the voiding phase too.

What are the risks of VCUG?

The VCUG is a relatively safe procedure that is meant to diagnose abnormalities of the urinary tract. While it is safe, it still has the following risks:

Infection due to introducing the catheter and dye
A minor risk of bleeding from the catheter entering the urinary tract
Discomfort from inserting the catheter
Allergic reactions to the dye

Sometimes, because a child is not used to peeing in front of other people, it may be hard for them to start peeing. This means that there can be a long wait between the filling phase and the voiding phase, and it is important to be patient with the child.

Please make sure that you understand the risks of proceeding with the VCUG.

"If it has risks or can be traumatic, why do we need to do it?"

The VCUG continues to be best way to diagnose certain abnormalities of the urinary tract, including reflux.

While ultrasounds, CT scans, and other tools may be helpful, they ultimately look at different things compared to the VCUG.

Because it is relatively invasive, your provider will often consider and maximize other treatment and diagnostic options before proceeding. However, if they find that the possible benefits outweigh the risk of VCUG, you will be encouraged to proceed.

What can we do to make the experience less traumatic for the patient?

In many centers in the world, professionals (child life specialists) and volunteers often help children through the experience. They can use distraction techniques, like toys or videos to watch during the VCUG, and they can help make the experience a more positive one for the patient.

In centers without such specialists, parents, aides, and the providers themselves can help distract the child. Toys, videos, music, and handheld games can help. You may want to bring some comforting materials for your child, like their favorite toy or blanket.

Older children benefit from good, easy-to-understand explanations about what to expect. Parents may often know best how to approach their child.

Lastly, good reward systems may help make the experience more positive. Because every child and every family is different, rewards may differ. Safe rewards to offer include stickers. Some parents make the experience a happier one by offering food or a special treat.

What happens after the VCUG?

Most of the time, a child can go home after a VCUG. There are usually no restrictions about eating or drinking thereafter.

Your urologist or provider will explain the results to you, and will advise you on the next steps.

At home, it is very important to watch out for fever, or other signs of infection.

The information in this infographic is for general information purposes only.

We encourage you to seek an individualized consult for the most appropriate management. You may book an appointment with us or with your preferred pediatric urologist or pediatric surgeon.

Please feel free to send us a message for questions on pediatric urologic health!