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What is a voiding cystourethrogram (VCUG)?

A VCUG, or a voiding cystourethrogram, is a minimally invasive test that uses a special x-ray technology called fluoroscopy to visualize your child's urinary tract and bladder.

A VCUG can help:

  • diagnose vesicoureteral reflux, a condition in which urine flows the wrong way, from the bladder back up to the kidneys
  • determine why your child has recurring urinary tract infections
  • discover if antibiotic treatment or anti-reflux surgery was effective
  • check if there are any abnormalities or blockages of the urethra

Frequently asked questions

How do I prepare my child for the VCUG?

We suggest talking to your child about why the test is important and what it is designed to accomplish. Explain that you will be with your child the entire time. If you are pregnant, you will not be able to be in the room when x-rays are taken. Please bring another family member or friend instead.

There are no restrictions on eating or drinking before the exam. If you have questions about the test or how to help your child prepare, you may call Child Life specialist Angela Franceschi at 617-355-6923 before you come to the hospital.

What happens before the VCUG?

In a survey of our patients, parents compared the discomfort of a VCUG as similar to or better than an immunization (Sandy N et al. Assessment of parental satisfaction in children undergoing voiding cystourethrogram without sedation. J Urol 2011; 185 (2):658:662).

The test is performed in the morning. On the day of the VCUG, you will speak with a radiologist, who will explain what will happen during the procedure and answer any questions or concerns you may have. A Child Life specialist or another clinical staff member will also be present to assist you in caring for your child during the test.

When you arrive in the Radiology Department:

  • You will check in.
  • You will be greeted by a staff member who will ask you some questions about your child's condition, explain the test, and answer your questions.
  • Your child will change into a hospital gown.
  • If your child is toilet-trained, he will be asked to go to the bathroom before the exam.
  • You and your child will be taken to the procedure room.
What happens during the test?
  • The technologist will help your child onto the fluoroscopy table.
  • Your child will need to remove underpants and socks.
  • Your child will need to lie on his or her back. Girls will position their legs like a frog's. Our VCUG team is very aware of the sensitive nature of the area to be tested and makes every effort to ensure privacy and comfort.
  • The technologist will put on clean gloves and wash between your child's legs with soap and water on cotton balls. It will be important for your child to remain still and to avoid touching his body below the waist. We realize laying still may be challenging for your child. We will give you suggestions on ways to distract your child in order to help them keep his body still.
  • The radiologist will then gently slide a very small tube (a catheter) coated with numbing gel into the small opening where urine comes out of the body (the urethra). The catheter can sometimes make children feel as though they need to urinate.
  • The tube will be taped in place and a urine sample will be collected.
  • A radio-opaque liquid will flow from a bottle through a tube, and into the catheter to fill your child's bladder. This contrast material illuminates the urinary tract on x-ray images.
  • Using fluoroscopy, a special x-ray technique, the radiologist will obtain images of your child's bladder filling and emptying. You will be able to see this on a monitor in the room.
  • If your child is old enough, we will ask him or her to urinate right on the table into a towel or a cup. This may be difficult, but it's important. Babies will urinate on his own when the bladder is full.
What happens after the VCUG?

The technologist will let you know when your child may get dressed and you may leave. If you have an appointment with another doctor in the hospital afterward, the radiologist will give you a note with the results to take with you. The radiologist will then prepare a written report for your child's doctor.

Your child may have some discomfort, pink urine, or feel a bit of stinging while going to the bathroom. This is normal and will go away. Drinking extra fluids will help.

Call your child's doctor if your child has red blood in the urine, pain, or a fever.

Are there risks associated with VCUG?

Your child will be exposed to ionizing radiation (x-rays) during this procedure. While we always attempt to minimize exposure to x-rays, we believe that the benefit of an accurate diagnosis outweighs the exposure that occurs during the exam.

Because children are more sensitive to radiation exposure than adults, we have been leaders in adjusting equipment and procedures to deliver the lowest possible dose to young patients.

How Boston Children's Hospital approaches VCUG

VCUGs are performed by the Department of Radiology's Diagnostic Radiology program, which has an experienced team of pediatric radiologists, nurses, technologists, and a Child Life specialist dedicated to making your child's visit as safe, pleasant, and comfortable as possible.

  • Pediatric radiologists, with extensive experience and training, perform the procedure.
  • Technologists have years of experience in imaging children from infancy to teenagers.
  • Skilled staff employ age-appropriate distraction techniques to help comfort patients prior to and during the procedure.
  • Equipment is designed specifically for pediatric use, which means age-appropriate care for children.
  • Protocols have been adapted to keep radiation exposure as low as reasonably achievable without compromising the image quality.

We perform more than 2,000 VCUGs a year, almost all without sedation. Our Child Life specialist supports your family before and during the exam.

Contact us

To schedule an appointment, please call the Department of Radiology at 617-919-SCAN (7226).

Voiding Cystourethrogram | Programs & Services