(Cystourethrography, Voiding Cystography, Voiding Cystourethrography, VCUG)
What is cystography?
Cystography is a diagnostic procedure that uses X-rays to examine the urinary bladder. Still X-ray pictures or fluoroscopy (a study of moving body structures—similar to an X-ray "movie") may be used.
During cystography, contrast dye is injected into the bladder. Contrast refers to a substance taken into the body that causes the particular organ or tissue under study to be seen more clearly. X-rays are taken of the bladder, and fluoroscopy may be used to study the bladder emptying while a person urinates (voiding cystography). Cystography may indicate how well the bladder empties during urination and whether any urine backs up into the kidneys (vesicoureteral reflux).
What are X-rays?
X-rays use invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs on film. X-rays are made by using external radiation to produce images of the body, its organs, and other internal structures for diagnostic purposes. X-rays pass through body structures onto specially-treated plates (similar to camera film) and a "negative" type picture is made (the more solid a structure is, the whiter it appears on the film).
In fluoroscopy, a continuous X-ray beam is passed through the body part being examined, and is transmitted to a TV-like monitor so that the body part and its motion can be seen in detail.
Other related procedures that may be used to diagnose problems of the bladder include kidney, ureters, and bladder (KUB) X-rays, CT (computed tomography) scan of the kidneys, kidney scan, renal angiogram, renal ultrasound, retrograde cystography, pyelogram (intravenous, antegrade, and retrograde), cystoscopy, cystometry, and uroflowmetry. Please see these procedures for additional information.
Urinary system parts and their functions
Two kidneys. A pair of purplish-brown organs located below the ribs toward the middle of the back. Their function is to remove liquid waste from the blood in the form of urine, keeping a stable balance of salts and other substances in the blood. The kidneys remove urea from the blood through tiny filtering units called nephrons. Each nephron consists of a ball formed of small blood capillaries, called a glomerulus, and a small tube called a renal tubule. Urea, together with water and other waste substances, forms the urine as it passes through the nephrons and down the renal tubules of the kidney.
Two ureters. These narrow tubes carry urine from the kidneys to the bladder. Muscles in the ureter walls continually tighten and relax forcing urine downward, away from the kidneys. If urine backs up, or is allowed to stand still, a kidney infection can develop.
Bladder. The bladder is a triangle-shaped, hollow organ located in the lower abdomen. It's held in place by ligaments that are attached to other organs and the pelvic bones. The bladder's walls relax and expand to store urine, and contract and flatten to empty urine through the urethra. The typical healthy adult bladder can store up to two cups of urine for two to five hours.
Two sphincter muscles. These circular muscles help keep urine from leaking by closing tightly like a rubber band around the opening of the bladder.
Nerves in the bladder. The nerves alert a person when it's time to urinate, or empty the bladder.
Urethra. This tube allows urine to pass outside the body.
Reasons for the Procedure
Cystography may be performed to assess the cause of hematuria (blood in the urine), recurring urinary tract infections (UTIs), or to assess the urinary system when there has been trauma to the bladder. Cystography may also be used to assess problems with bladder emptying and urinary incontinence.
Obstructions and strictures (narrowing) of the ureters or urethra may be evaluated by cystography. Cystography may be used to assess enlargement of the prostate gland.
Cystography may be performed before and/or after certain surgeries of the spine to assess possible problems with the nerves leading to the bladder from the spine. It may also be performed following trauma to assess for a tear in the bladder wall.