Voiding Cystourethrogram for Children

A children's (pediatric) voiding cystourethrogram (VCUG) is an X-ray of a child's bladder and lower urinary tract that uses a special type of X-ray called fluoroscopy and a contrast material.

Fluoroscopy makes it possible to see internal organs in motion. When the bladder is filled with and then emptied of a water-soluble contrast material, the radiologist is able to view and assess the anatomy and function of the bladder and lower urinary tract.

A voiding cystourethrogram is often recommended after a urinary tract infection or kidney infection or to check for a condition known as vesicoureteral (VU) reflux.

About VU Reflux

Urine is produced in the kidneys and flows through the ureter, the tube that carries urine from each kidney to the bladder. A valve mechanism prevents urine from backing up into the kidneys as the bladder gets full. Urine leaves the bladder through the urethra and is eliminated from the body during urination.

In some children, an abnormality in the valve or the ureters allows urine to flow backwards, a condition called VU reflux. In mild cases urine backs up into the lower ureter. In severe cases it can back up into a swollen kidney. Usually, children with this condition are born with it. Other causes include:

  • Blockage to the bladder
  • abnormal urination with very high pressure within the bladder
  • Incomplete emptying of the bladder
  • Urinary tract infections

Urinary tract infection may be the only symptom of the problem.