What is Arterial Catheterizations?
Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection is needed to produce pictures of blood vessels in the body.
Angiography is performed using:
• x-rays with catheters
• computed tomography (CT)
• magnetic resonance imaging (MRI)
CT angiography uses a CT scanner to produce detailed images of both blood vessels and tissues in various parts of the body. An iodine-rich contrast material (dye) is usually injected through a small catheter placed in a vein of the arm. A CT scan is then performed while the contrast flows through the blood vessels to the various organs of the body. After scanning, the images will be processed using a special computer and software and reviewed in different planes and projections.
What to Expect
This examination is usually done on an outpatient basis. A nurse or technologist will insert an intravenous (IV) line into a small vein in your hand or arm. A small amount of blood will be drawn before starting the procedure to make sure that your kidneys are working and that your blood will clot normally. A small dose of sedative may be given through the IV line to lessen your anxiety during the procedure.
The area of the groin or arm where the catheter will be inserted is shaved, cleaned, and numbed with local anesthetic. The radiologist will make a small incision (usually a few millimeters) in the skin where the catheter can be inserted into an artery. The catheter is then guided through the arteries to the area to be examined. After the contrast material is injected through the catheter and reaches the blood vessels being studied, several sets of x-rays are taken. Then the catheter is removed and the incision site is closed by placing pressure on the area for approximately 10 to 20 minutes (or by using a special closure device).
When the examination is complete, you will be asked to wait until the radiologist determines that all the necessary images have been obtained. Your intravenous line will be removed. A catheter angiogram may be performed in less than an hour; however, it may last several hours.
Preparation
You should inform your physician of any medications you are taking and if you have any allergies, especially to barium or iodinated contrast materials. Also inform your doctor about recent illnesses or other medical conditions.
You may be asked to remove some or all of your clothes and to wear a gown during the exam. You may also be asked to remove jewelry, removable dental appliances, eye glasses and any metal objects or clothing that might interfere with the x-ray images.
Women should always inform their physician and x-ray technologist if there is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to radiation. If an x-ray is necessary, precautions will be taken to minimize radiation exposure to the baby. If you are breastfeeding at the time of the exam, you should ask your doctor how to proceed. It may help to pump breast milk ahead of time and keep it on hand for use after contrast material has cleared from your body, about 24 hours after the test.
If you are going to be given a sedative during the procedure, you may be asked not to eat or drink anything for four to eight hours before your exam. Be sure that you have clear instructions from your health care facility.
If you are sedated, you should not drive for 24 hours after your exam and you should arrange for someone to drive you home. Because an observation period is necessary following the exam, you may be admitted to the hospital for an overnight stay if you live more than an hour away.