Alternative Names cerebral angiogram, neuroangiography, neuroangiogram
Definition Cerebral angiography is an imaging test used to diagnose abnormalities of arteries in the neck and brain. Sometimes the test is used to evaluate the veins in the brain and neck. This test involves the use of special thin tubes called catheters, a TV system, and an x-ray machine.
Who is a candidate for the test? A doctor may advise this test for a person who has or is suspected to have one of the following conditions:
stroke, which is brain damage that occurs from a lack of oxygen to the brain
How is the test performed? This test requires that a person lie on a flat platform. The platform is inside a special room that is set up for this test. This room contains cameras, TV screens, and x-ray devices. The doctor who usually performs the procedure is called a radiologist. During the procedure, the doctor and the assistants operate the equipment. A nurse checks the person's vital signs, such as the heart rate and blood pressure, during the examination.
The doctor must choose an artery for insertion of the catheter. An artery in the right groin, called the femoral artery, is usually used. The skin in the groin area is numbed with a local anaesthetic. Once the skin is numb, a small needle is inserted through the skin and into the artery. The doctor can then insert a catheter into the artery through the small puncture made with the needle. The catheters are very thin devices and are several inches long.
Once the catheter is placed into the artery, it can be advanced into the largest artery in the body, which is called the aorta. This artery connects directly to the heart. The important arteries that supply blood and oxygen to the neck and brain come from the aorta. An x-ray machine is used to help guide the catheter into proper position.
A special substance called a contrast agent is used to clearly see the arteries. The contrast agent is injected into the catheter and enters the arteries. This allows the arteries to be clearly seen, because the contrast agent used is easily seen when x-ray pictures are taken. The x-ray machine can be used to take several pictures as the contrast agent travels through the arteries. The images are projected onto a TV or video screen so that the doctor can see the arteries clearly during the test.
The doctor usually takes several pictures of the arteries filled with contrast agent from different angles and positions. Usually, several injections of the contrast agent are needed.
The standard test will typically take less than an hour. In more complex cases, the examination may last for several hours. In some cases, the doctor may see an abnormality during the test that can be corrected during the examination. For example, a procedure called angioplasty is sometimes used to open up clogged arteries. This involves inserting tiny tools through the catheter that can widen or open the area of blockage.
What is involved in preparation for the test? Special preparation is needed before the test. A brief physical examination is done to evaluate pulses in the groin and legs. If a person has a weak pulse in the groin, a different artery will be used to insert the catheter. A review of the person's medical and surgical history is also needed. Questions may be asked about:
whether the person takes blood thinning medications, such as aspirin or warfarin
whether the person has a bleeding tendency or any blood disorders
whether the person has any problem with or disease that affects the kidneys
whether the person has had a prior allergic reaction to contrast agent or dye
Before the test, the person's blood is tested to check for any bleeding tendency and to check kidney function. A woman of childbearing age will be screened for pregnancy, usually with a urine or blood pregnancy test. This is done because the radiation from the test could harm an unborn child.
The person cannot eat or drink anything 6-8 hours before the test. Dentures, eyeglasses, and jewellery, such as a necklace or earrings, should be removed before the examination.
The risks, benefits, and complications of the test are usually explained to the person on the day of the procedure. Some possible complications from the test include:
If procedures are done during the examination, such as angioplasty, additional risks are involved. These will be discussed by the doctor before the test.
This test may be done on an outpatient basis. This means that the person can go home after the test. Sometimes a person must stay in the hospital for a day or more after the test. Often, this test is used for people in the hospital with serious or life-threatening central nervous system disorders.
What do the test results mean? The doctor who performs the test is usually the one who reviews the results. This involves looking at the pictures taken during the examination to check for any abnormalities. The doctors will use the results of this test to help decide the next course of action or a treatment plan.
Author: Lanita Dawson, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
