After the patient's bladder is filled with a liquid called contrast material, an X-ray machine sends beams of radiation through the abdomen and pelvis, and images are recorded on special film or a computer. These images help doctors see problems in parts of the urinary system, including the bladder, urethra (the tube connecting the bladder with the outside of the body), and the ureters (the tubes connecting the kidneys to the bladder).
A radiologist takes the X-rays using a technique called fluoroscopy. While the contrast material fills your child's bladder, and then while your child empties the bladder, the radiologist watches an onscreen X-ray video of the liquid moving through the urinary system and a series of X-ray films is recorded.
In general, X-rays are very safe. Although there is some risk to the body with any exposure to radiation, the amount used in a VCUG is small and not considered dangerous. It's important to know that Nemours radiologists use the minimum amount of radiation required to perform the study properly.