VCUG: voiding cystou­rethrogram

What is a VCUG?

A voiding cystourethrogram (VCUG) is a test in which the bladder is filled with contrast dye and followed with X-rays. Images are taken while the bladder fills and while the child passes urine.

What does it show?

• Vesicoureteral reflux (VUR): whether urine flows back into the ureters and the kidney, and the grade,
• the urethra: in boys, posterior urethral valves, narrowings,
• the shape of the bladder: wall thickening, diverticula, ureterocele,
• how the bladder empties.

When is it needed?

• widening of the ureters on ultrasound, or severe hydronephrosis on both sides,
• suspected valves in a boy,
• after a febrile urinary tract infection: a first febrile infection before 12 months of age, recurrent febrile infections, an abnormal ultrasound or DMSA, or an atypical infection at any age (not every child with an infection needs a VCUG),
• monitoring reflux or checking the result after treatment.

How is it done?

1. The child lies on the X-ray table, and the genitals are cleaned with a sterile solution.
2. A very thin, soft catheter is placed through the urethra into the bladder. This may cause brief discomfort, but it is not painful.
3. The contrast dye slowly fills the bladder, and images are taken.
4. When the bladder is full, the child passes urine on the table, and images of the urethra are taken at that moment.

Preparation

• Fasting is not needed.
• Explain the test to your child in simple words suited to his or her age.
• Bring a favorite toy or tablet.
• Your child must not have a urinary tract infection at the time of the test. The doctor sometimes prescribes a short course of antibiotics.

Afterward

• Drink plenty of fluids.
• There may be mild burning when passing urine for 1–2 days.
• If there is a fever, see a doctor.