Renal arteriography is a special x-ray of the blood vessels of the kidneys. During this test, a dye (called "contrast medium") is injected into one or more of your arteries to help them show up better on the x-ray. The blood vessels of the kidneys are hard to see with just plain x-rays.

Renal arteriography is also called renal angiography.

See also: Renal venogram.

This test is done in the hospital. You will lie on an x-ray table.

The health care provider will clean and shave the area of the body (usually near the groin) where a needle will be placed into the artery. A local numbing medicine will be put on the area before inserting the needle.

Once the needle is in the proper position, a thin guide wire passes through it. The needle is taken out, and a long, narrow, flexible tube called a catheter is put in its place. The catheter runs over the wire and pushed up into the main blood vessels of the pelvis to the aorta (the main blood vessel running down from the heart to the lower body).

During the procedure, a fluoroscope sends special x-ray images of the body to a TV monitor. This helps the radiologist guide the catheter into the right position.

Once in place, the dye is sent through the catheter into the renal artery. X-ray images are taken as the dye moves through the blood vessels. Saline (sterile salt water) contain a blood thinner may also be sent thru the catheter to keep the blood in the area from clotting.

After the x-rays are taken, the catheter is taken out. Pressure is immediately applied to the area of the needle stick for 10 to 15 minutes or more to stop the bleeding. After that time, the area is checked and a bandage is applied. The leg should be kept straight for 6 hours after the procedure.

Digital Subtraction Angiography (DSI) uses a computer to "subtract" out the bones and tissues in the region so that only the blood vessels filled with the dye can be seen.

Tell the health care provider if you are pregnant and if you have ever had any bleeding problems. Report any allergic reactions you have ever had, especially those you have had to x-ray contrast material or any iodine substance.

You must sign a consent form. Do not eat or drink anything for 8 hours before the test. You will be given a hospital gown to wear and asked to remove all jewelry. You may be given a sedative or pain pill before the procedure.

The x-ray table is hard and cold. You may wish to ask for a blanket or pillow. There is a sting when the anesthetic (numbing medicine) is given. This does not numb the artery so there will be brief, sharp pain as the catheter is inserted. There is a feeling of pressure as the catheter is moved into the body.

As the dye is injected, you may feel a warm or burning sensation. There may be slight tenderness and bruising at the site of the injection after the test.

The test is done to look at the blood vessels that feed the kidney. It may show:

• Renal stenosis (narrowing of the blood vessels of the kidneys)
• Blood clots
• Aneurysm (a widening of the vein or artery)
• Kidney disease or failure

Renal arteriography is often used to examine donors and recipients before a kidney transplant to determine the number of arteries and veins on each kidney.

Renal angiography may show the presence of tumors, narrowing of the artery or aneurysms (widening of the vein or artery), blood clots, or bleeding in the kidney.

Additional conditions under which the test may be performed:

• Acute arterial occlusion of the kidney
• Acute renal failure
• Atheroembolic renal disease
• Renal artery stenosis
• Renal cell carcinoma

The procedure is generally safe, but risks may include:

• Allergic reaction to the dye (contrast medium)
• Damage to artery or artery wall, which can lead to blood clots

There is low radiation exposure. However, most experts feel that the risk related most x-rays is smaller than other risks we take every day, such as driving in cars. Pregnant women and children are more sensitive to the risks related to x-rays.

The test should NOT be done if you are pregnant or tend to bleed.

MRA (Magnetic Resonance Angiography) can be performed on those who can not have a renal arteriography exam. MRA is non-invasive and can provide similar imaging of the renal vessels.