A voiding cystourethrogram (VCUG) is a fluoroscopic examination of the bladder and urethra while the patient is micturating. It is most often used in the pediatric population to confirm or rule out the diagnosis of vesicoureteral reflux (VUR).
This is a medical condition in which urine flows in a retrograde fashion from the bladder to the ureters, and may give rise to serious complications such as renal scarring and kidney failure.
VCUG is a useful diagnostic tool because it can help to detect almost any structural abnormality of the bladder and lower urinary tract, including ureteral strictures (i.e. narrowing).
What to Expect
The entire procedure may last up to half an hour and is more or less painless, but children may be scared by the unfamiliar surroundings. Therefore, parents are encouraged to be present during the process to reassure their children that things are all right, and there is nothing to be worried about.
It is important that any allergies that the child has to medications or X-ray contrast material are communicated to the physician before beginning. Any jewelry or accessories that may disturb the image are also removed from the body.
To start the procedure, the patient is placed on an examination table and a catheter is inserted into the urethra under sterile conditions to avoid iatrogenic infection. Fluoroscopic screening is then begun.
Saline mixed with contrast agent is infused through the catheter to reach the bladder until it is filled to capacity. This capacity is determined based on the patient’s biophysical findings, such as weight and age.
The contrast agent assists to visualize the bladder. Once filled, the catheter is removed and the patient urinates, while pictures of the emptying bladder are simultaneously being taken, at different angles,.
These images are taken during both the emptying and filling of the bladder, because if the patient has VUR, there may be reflux during either process. The test is complete when the bladder is emptied and a final image is taken 60 seconds later.
Following the procedure, the radiologist will analyze the acquired pictures and make a report that is sent to the physician attending to the patient. When normal, the bladder and urethra will show typical size and function.
Abnormal results may have several connotations, which include, but are not limited to, neurogenic bladder, reflux nephropathy, bladder/urethral diverticula and ureterocele (i.e. the ballooning of the distal ureter as it opens into the bladder to form a pouch).
Patients are subsequently managed according to the pathology discovered.
Risks and Complications
The process itself is fairly safe and most of the complications associated with it are seen in the period following the procedure. The most common complains are perineal discomfort and painful urination.
These are mostly experienced as a result of the catheterization rather than being reactions to the saline or contrast dye. This pain and discomfort, fortunately, is transient and resolves within a few hours.
Another possible and more serious complication following a VCUG is a urinary tract infection (UTI). This should be minimized by using aseptic technique during the catheterization. Other complications, such as bladder perforation and anaphylactic reaction to the contrast agent are fortunately rare.
Reviewed by Liji Thomas, MD.