(Retrograde Ureteropyelogram, Retrograde Pyelography, Retrograde Ureteropyelography)
What is a retrograde pyelogram?
A retrograde pyelogram is a type of X-ray that allows visualization of the bladder, ureters, and renal pelvis. Generally, this test is performed during a procedure called cystoscopy—evaluation of the bladder with an endoscope (a long, flexible lighted tube). During a cystoscopy, contrast dye, which helps enhance the X-ray images, can be introduced into the ureters via a catheter.
As the techniques and technology of ultrasound (high-frequency sound waves) and contrast dye have improved, other procedures such as CT (computed tomography) scan and renal ultrasound have become more commonly used than retrograde pyelography.
What is an X-ray?
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).
Other related procedures that may be used to diagnose problems of the upper urinary tract include kidney, ureters, and bladder (KUB) X-ray, CT (computed tomography) scan of the kidneys, renal ultrasound, renal angiogram, intravenous pyelogram, antegrade pyelogram, and renal venogram. Please see these procedures for additional information.
How does the urinary system work?
The body takes nutrients from food and converts them to energy. After the body has taken the food that it needs, waste products are left behind in the bowel and in the blood.
The urinary system keeps chemicals, such as potassium and sodium, and water in balance, and removes a type of waste, called urea, from the blood. Urea is produced when foods containing protein, such as meat, poultry, and certain vegetables, are broken down in the body. Urea is carried in the bloodstream to the kidneys.
Other important functions of the kidneys include blood pressure regulation, and the production of erythropoietin, which controls red blood cell production in the bone marrow.
Urinary system parts and their function
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.
Keep a stable balance of salts and other substances in the blood.
Produce erythropoietin, a hormone that aids the formation of red blood cells.
Regulate blood pressure.
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. About every 10 to 15 seconds, small amounts of urine are emptied into the bladder from the ureters.
Bladder. The bladder is a triangle-shaped, hollow organ located in the lower pelvis. 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. These nerves alert a person when it's time to urinate, or empty the bladder