What is a Voiding Cystourethrogram?
A children’s (pediatric) voiding cystourethrogram (VCUG) is an x-ray examination of a child’s bladder and lower urinary tract that uses a special form 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.
What are some common uses of the procedure?
A voiding cystourethrogram enables a radiologist to detect abnormalities in the flow of urine through the lower urinary tract. This examination is often recommended after a urinary tract infection to check for a condition known as vesicoureteral (VU) reflex. A VU reflux is an abnormality in the value or the ureters that allows urine to flow backwards into the lower ureter (mild cases) or into the kidney (severe cases). Most often, children with this condition are born with it. Other causes include:
- Bladder obstruction
- Abnormal urination with very high pressure within the bladder
- Incomplete emptying of the bladder
- Urinary tract infection
Urinary tract infection may be the only symptom of the problem.
How should my child and I prepare?
You should inform your physician of any medications your child is taking and if he or she has any allergies, especially to contrast materials. Also inform your doctor about recent illnesses or other medical conditions.
Your child does not need to fast or wear special clothing. Explain to your child what will happen during the examination to manage expectations. Your child will have to remove all clothing and wear a gown. Sedation is rarely needed.
How is the procedure performed?
The examination is usually performed on an outpatient basis. The technologist begins by positioning the child on the table. Infants and young children may be wrapped tightly in a blanket or other restraint to help them lie still during the procedure. An x-ray of the abdomen may be taken before the urinary bladder is catheterized. After cleaning the genital area, a catheter is inserted through the urethra, the tube that carries urine from the bladder out of the body. Then, the bladder is filled with a liquid contrast material. When the bladder is full, the child will urinate on the x-ray table. The radiologist or technologist will use fluoroscopy to monitor the filling of the bladder and urination. X-ray images will be obtained during this time. Once the exam is complete, the catheter is removed.
The radiologist will check to see if any of the liquid contrast material goes backward into one or both ureters and kidneys and whether the shape and contour of the bladder and urethra are normal.
A voiding cystourethrogram is usually completed within 30 minutes.
What will my child experience during and after the procedure?
A voiding cystourethrogram may frighten some children. The antiseptic used to clean and prepare for the insertion of the catheter may feel cold. Some children may experience discomfort when the catheter is inserted and the bladder is filled with the liquid contrast material. Most children accept the procedure after hearing an explanation of all its parts. A parent may be allowed to stay in the examination room to comfort the child.
Minimizing Radiation Exposure
Special care is taken during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection organizations continually review and update the technique standards used by radiology professionals.
Modern x-ray systems have very controlled x-ray beams and dose control methods to minimize stray radiation, ensuring minimal radiation exposure.