An Intravenous Pyelogram (IVP) is an x-ray examination of the kidneys, ureters and urinary bladder. Most people are familiar with x-ray images, which produce a still picture of the body's interior by passing small, highly controlled amounts of radiation through the body, and capturing the resulting shadows and reflections on film. An IVP study uses a contrast material to enhance the x-ray images. The contrast material is injected into the patient's system, and its progress through the urinary tract is then recorded on a series of quickly captured images. The exam enables the radiologist to review the anatomy and the function of the kidneys and urinary tract.
What are some common uses of the procedure?
A radiologist can use an IVP study to find the cause of a wide variety of disorders, including frequent urination, blood in the urine, or pain in the side or lower back. The IVP exam can enable the radiologist to detect problems within your urinary tract resulting from kidney stones; enlarged prostate; internal injuries after an accident or trauma; tumors in the kidney, ureters, or urinary bladder; and other changes.
How should I prepare for the procedure?
You should tell your doctor about any allergies you have to foods or medications, as well as any recent illnesses or other medical conditions. If you are have diabetes, make sure your doctor is aware of your condition and the medications you take. Women should always inform their doctor or x-ray technologist if there is any possibility that they are pregnant. Your doctor will give you detailed instructions on how to prepare for your IVP study. You will likely be instructed not to eat or drink after midnight the night before your exam. You may also be asked to take a mild laxative (in either pill or liquid form) the evening before the procedure. Follow your doctor's instructions. Once you arrive at the imaging center, you may be asked to change into a gown before your examination. You will also be asked to remove jewelry, eyeglasses, or any metal objects that could obscure the images. Underwear with metallic components should also be removed.
What does the equipment look like?
The equipment used for most IVP examinations consists of a large, flat table. Suspended above the table is an apparatus containing the x-ray tube. The apparatus moves on a jointed "arm" so that it can be properly positioned.
How does the procedure work?
Different tissues, such as bone, blood vessels, and muscles and other soft tissues, absorb x-ray radiation at different rates. When a special film plate is exposed to the absorbed x-rays, an image of the inside of the body is captured.
An IVP study requires the use of a contrast material to help tissues show more clearly on the x-ray film. As the contrast material moves into and through the kidneys, ureters, and urinary bladder, the technologist captures a series of images that track its progress. By reviewing these images, a radiologist can then assess abnormalities in the urinary system, as well as how quickly and efficiently the patient's system is able to handle waste.
How is the procedure performed?
Before introducing the contrast material, the radiologist or technologist will ask whether the patient has any allergies and whether the patient has a history of diabetes, asthma, a heart condition, kidney problems, or thyroid conditions. These conditions may indicate a higher risk of reaction to the contrast material, or potential problems eliminating the material from the patient's system after the exam. You may also be asked if you have had any prior surgery on the urinary system.
An IVP examination is usually done on an outpatient basis. The patient is positioned on the table, and a contrast material is injected, usually in a vein in the patient's arm. Images are taken both before and after the injection of the contrast material. As the contrast material is processed by the kidneys, a series of images is captured to determine the actual size of the kidneys and to show the collecting system as it begins to empty. Some kidneys don't empty at the same rate and delayed films from thirty minutes to three or four hours may be requested. However, a typical IVP study usually takes about an hour.
What will I experience during the procedure?
Aside from the minor sting from the injection of contrast material, an IVP causes no pain. When the contrast material is injected, some people report feeling a flush of heat and, sometimes, a metallic taste in the mouth. These common side effects usually disappear within a minute or two and are no cause for alarm. Some people experience a mild itching sensation. If it persists or is accompanied by hives, the itch can be treated easily with medication. In rare cases, a patient may become short of breath or experience swelling in the throat or other parts of the body. These can be indications of a more serious reaction to the contrast material that should be treated promptly, so tell the radiologist or technologist immediately if you experience these symptoms.
During the imaging process, you may be asked to turn from side to side and to hold several different positions, to enable the radiologist to capture views from several angles. Near the end of the exam, you may be asked to empty your bladder so that an additional film can be taken of your urinary bladder as it empties.
The contrast material used for IVP studies will not discolor your urine or cause any discomfort when you urinate. If you experience such symptoms after your IVP exam, they are likely to indicate some other problem. Let your doctor know right away.
Who interprets the results and how do I get them?
A radiologist, a physician experienced in IVP and other radiology examinations, will analyze the images and send a signed report with his or her interpretation to the patient's primary care physician. The patient receives IVP results from the referring physician who ordered the test results. New technology also allows for distribution of diagnostic reports and referral images over the internet at many facilities.