An intravenous pyelogram (PIE-uh-low-gram) is an X-ray exam of the urinary tract. Also called an excretory urogram, this exam allows your care team to see the parts of your urinary tract and how well they work.

This test can help with diagnosis of problems such as kidney stones, enlarged prostate, urinary tract tumors or problems present at birth.

During the test, an X-ray dye is injected into a vein in your arm. The dye flows into the kidneys, ureters and bladder, outlining each of these structures. X-ray pictures are taken at specific times during the exam.

You may need an intravenous pyelogram if you have symptoms, such as back or side pain or blood in the urine, that could mean you have a problem in your urinary tract.

This test can help your doctor diagnose certain conditions, such as:

• Kidney stones.
• Enlarged prostate.
• Urinary tract tumors.
• Problems with the structure of the kidneys, such as medullary sponge kidney. This condition is present at birth and affects the tiny tubes inside the kidneys.

Intravenous pyelogram was often used to check for urinary tract problems. But newer imaging tests, including ultrasound exams and CT scans, take less time and don't need X-ray dye. These newer tests are now more common.

But an intravenous pyelogram still can be a helpful tool for your health care provider to:

• Find problems with structures in the urinary tract.
• Detect kidney stones.
• Show a blockage, also called an obstruction, in the urinary tract.

An intravenous pyelogram is generally safe. Complications are rare, but they can happen.

Injection of X-ray dye can cause side effects such as:

• A feeling of warmth or flushing.
• A metallic taste in the mouth.
• Nausea.
• Itching.
• Hives.

Rarely, severe reactions to the dye occur, including:

• Very low blood pressure.
• A sudden, full-body reaction that can lead to breathing problems and other life-threatening symptoms. This is called anaphylactic shock.
• Cardiac arrest, where the heart stops beating.

During X-rays, you're exposed to low levels of radiation. The amount of radiation you're exposed to during an intravenous pyelogram is small. The risk of any damage to cells in your body is low.

But if you're pregnant or think that you may be pregnant, tell your provider before you have an intravenous pyelogram. Your provider may decide to use another imaging test.

To prepare for the exam, tell your care team if you:

• Have any allergies, particularly to iodine.
• Are pregnant or think you might be pregnant.
• Have had a previous severe reaction to X-ray dyes.

You may need to avoid eating and drinking for a certain amount of time before an intravenous pyelogram. Your doctor also may advise you to take a laxative the night before the exam.

Before your exam, a member of your care team may:

• Ask you questions about your medical history.
• Check your blood pressure, pulse and body temperature.
• Ask you to change into a hospital gown and remove jewelry, eyeglasses and any metal objects that may obscure the X-ray images.
• Place an intravenous line into a vein in your arm through which the X-ray dye will be injected.
• Ask you to empty your bladder

During intravenous pyelogram

You lie on your back on an exam table. An X-ray machine is positioned over your abdomen. After that:

• An X-ray image is taken to show your urinary tract before any dye is injected.
• X-ray dye is injected through the intravenous line in your arm.
• X-ray images are taken at timed intervals as the dye flows through the kidneys to the ureters and into the bladder.
• Toward the end of the exam, you may be asked to urinate to empty your bladder again.
• After you return to the exam table, another X-ray image is taken of your empty bladder.

After intravenous pyelogram

When your exam is done, the intravenous line is removed from your arm. You can return to your usual activities.

A doctor who specializes in reading X-rays reviews and interprets the images from your exam. The doctor is a radiologist. The radiologist sends a report to your health care provider. You'll talk with your provider about the test results at a follow-up appointment.