Vesicoureteral Reflux
Diagnosis

It's especially important to promptly diagnose and treat VUR in infants and small children, since without treatment most of them will develop another urinary tract infection. Waiting until a child has had two or more urinary tract infections before having an evaluation increases the risk of permanent kidney damage or scarring.

Vesicoureteral reflux is usually diagnosed in one of two ways. Children who have a urinary tract infection that's been confirmed by a lab test will have an X-ray evaluation called a voiding cystourethrogram. During the test, the bladder is filled with contrast material that shows up on X-rays. If the child has VUR, the contrast material will backflow into the ureter and kidneys.

Alternately, VUR may be suspected when a prenatal ultrasound reveals that the fetus has dilated kidneys. If this occurs, a voiding cystourethogram is done soon after the birth of the baby.

Other tests may include:

• Kidney and Bladder Ultrasound — This test is routinely recommended prior to the voiding cystourethrogram. It provides an outline of the kidneys, ureters and bladder, and we use it to look for less common urinary tract defects that can cause urinary tract infections or kidney dilation. The test doesn't require radiation and is painless.
• Kidney (Renal) Scan — A kidney scan may be performed if the above tests are abnormal or if your child has repeated, fever-causing infections. A kidney scan shows the actual function and drainage of the kidneys, and it can also reveal if there's kidney damage or scarring from a previous urinary tract infection.
• Nuclear Cystogram — This test is very similar to the voiding cystourethrogram, but it involves less radiation and is very sensitive for reflux. The voiding cystourethrogram is the preferred test for initially diagnosing reflux, because it provides a clearer picture of the lower urinary tract and therefore can rule out other less common abnormalities, as well as grade the severity of the reflux. Once the diagnosis has been made by the voiding cystourethrogram, the nuclear cystogram is the recommended follow-up test. The nuclear cystogram is also used to screen siblings of children who have reflux to determine if they also have the condition.

Reflux is graded on a scale of one to five, with one being a mild form and five being severe. The degree of reflux is used to make decisions on how to treat the child. More severe grades are less likely to clear up spontaneously and more likely to cause kidney damage if they're not treated.

Reviewed by health care specialists at UCSF Benioff Children's Hospital.
Last updated July 14, 2010