(IVP, Intravenous Urography, IVU, Excretory Urography)
What is an intravenous pyelogram?
An intravenous pyelogram (IVP) is a type of X-ray that allows visualization of the kidneys and ureters after the injection of a contrast dye. The dye helps enhance the image on an X-ray film.
As the contrast dye moves into and through the kidneys, ureters, and bladder, X-rays taken at short intervals can capture its movement. A delay in the contrast dye moving through the urinary system may indicate an obstruction in the kidney's blood flow or poor kidney function.
A radiologist can then assess the function and detect abnormalities of the urinary system. This test is usually ordered as one of the first tests in cases of suspected kidney disease or urinary tract disorders.
What is an X-ray?
X-rays use invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs on film or digital media. 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) or digital media and a "negative" type picture is made (the more solid a structure is, the whiter it appears on the film).
IVP may be performed at the same time as a computed tomography (CT) scan of the kidneys (also called nephrotomography). This test, like the IVP, is performed after contrast dye has been injected, but unlike a standard X-ray, provides images of layers or "slices" of the kidney.
As newer technologies are developed, other procedures such as CT, MRI, and ultrasound (high-frequency sound waves) are often used instead of IVP.
Other related procedures that may be used to diagnose problems of the upper urinary tract include kidney, ureters, and bladder (KUB) X-ray, CT scan of the kidneys, renal ultrasound, renal angiogram, antegrade pyelogram, retrograde 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 functions:
Two kidneys. A pair of purplish-brown organs located below the ribs toward the middle of the back. 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. The kidneys' 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
Two ureters. These are narrow tubes that 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. A triangle-shaped, hollow organ located in the lower abdomen. It is 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 are circular muscles that help keep urine from leaking by closing tightly like a rubber band around the opening of the bladder
Nerves in the bladder. Nerves that alert a person when the bladder is full and it is time to urinate, or empty the bladder
Urethra. The tube that allows urine to pass outside the body
Reasons for the procedure
An IVP can demonstrate the size, shape, and structure of the kidneys, ureters, and bladder. It can also be used to evaluate kidney function, the presence of kidney disease, ureteral or bladder stones, enlarged prostate, trauma or injury, and tumors. IVP may be performed in the presence of flank pain or spasmodic pain in the kidney area.
A CT scan of the kidneys, sometimes performed at the same time as an IVP, aids in more accurately diagnosing and locating kidney tumors and lacerations of the kidneys resulting from trauma.
There may be other reasons for your physician to recommend an IVP.
Risks of the procedure
You may want to ask your doctor about the amount of radiation used during the procedure and the risks related to your particular situation. It is a good idea to keep a record of your past history of radiation exposure, such as previous scans and other types of X-rays, so that you can inform your doctor. Risks associated with radiation exposure may be related to the cumulative number of X-ray examinations and/or treatments over a long period of time.
If you are pregnant or suspect that you may be pregnant, you should notify your doctor. Radiation exposure during pregnancy may lead to birth defects.
If contrast dye is used, there is a risk for allergic reaction to the dye. Patients who are allergic to or sensitive to medications, contrast dye, or iodine should notify their doctor. An allergy to shellfish, while previously thought to be related to a contrast allergy, is no longer relevant.
Patients with kidney failure or other kidney problems should notify their doctor. In some cases, the contrast dye can cause kidney failure, especially if the person is taking Glucophage (a diabetic medication) or other related drugs.
Possible complications of IVP include, but are not limited to, problems with urination, urinary tract infections, allergic reaction, and/or renal toxicity resulting from the contrast dye.
There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your doctor prior to the procedure.
Certain factors or conditions may interfere with IVP. These factors include, but are not limited to, the following:
Feces or gas in the colon
Poor blood flow to the kidneys
Barium in the intestines from a previous barium procedure
Before the procedure
Your doctor will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure.
You will be asked to sign a consent form that gives your permission to do the procedure. Read the form carefully and ask questions if something is not clear.
You will need to fast for a certain period of time prior to the procedure. Your physician will notify you how long to fast, whether for a few hours or overnight.
If you are pregnant or suspect that you may be pregnant, you should notify your doctor.
Notify your doctor if you have ever had a reaction to any contrast dye, or if you are allergic to iodine.
Notify your doctor if you have are sensitive to, or are allergic to, any medications, latex, tape, and anesthetic agents (local and general).
Notify your doctor of all medications (prescribed and over-the-counter) and herbal supplements that you are taking. If you are diabetic and taking a medication called Glucophage, you may be asked to stop taking that medication 24 hours before the test.
Notify your doctor if you have a history of bleeding disorders or if you are taking any anticoagulant (blood-thinning) medications, aspirin, or other medications that affect blood clotting. It may be necessary for you to stop these medications prior to the procedure.
A laxative may be prescribed the night before the test and a cleansing enema or suppository may be given a few hours before the procedure.
Your doctor may request a blood test to assess your kidneys' ability to tolerate the contrast dye.
Based on your medical condition, your doctor may request other specific preparation.
During the procedure
An IVP may be performed on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your doctor's practices.
Generally, an IVP follows this process:
You will be asked to remove any clothing, jewelry, or other objects that may interfere with the procedure.
If you are asked to remove clothing, you will be given a gown to wear.
An intravenous (IV) line will be inserted in your hand or arm.
You will be asked to lie face up on an X-ray table.
A preliminary KUB X-ray will be taken.
Contrast dye will be injected into the IV. You may feel some effects when the dye is injected into the IV line. These effects include a flushing sensation, a salty or metallic taste in the mouth, a brief headache, itching, or nausea and/or vomiting. These effects usually last for a few moments.
A series of X-rays will be taken at timed intervals, generally over a 30-minute period, as the dye travels through the kidneys and urinary tract. You may be asked to assume various positions while the X-rays are being taken.
You will be asked to empty your bladder. You may be given a bedpan or urinal, or you may be allowed to go to the restroom.
After you have emptied your bladder, a final X-ray will be taken to examine the amount of contrast dye remaining in the bladder.
After the procedure
You may resume your usual diet and activities, unless your doctor advises you differently.
You should monitor your fluid intake and amount of urine voided over the next 24 hours. You may be instructed to increase your fluid intake in order to help flush the contrast dye from your body.
Notify your doctor to report any of the following:
Fever and/or chills
Redness, swelling, or bleeding or other drainage from the IV site
Blood in your urine
Nausea, itching, and/or sneezing
Your doctor may give you additional or alternate instructions after the procedure, depending on your particular situation.