- cerebral angiogram
Cerebral angiography is an imaging test used to diagnose problems with the arteries or veins in the neck and brain. This test involves the use of special thin tubes called catheters, an X-ray machine, and a television-like monitor.
Who is a candidate for the test?
A healthcare professional may advise this test for a person who has or is suspected to have one of the following conditions:
an injury to the neck or face
brain tumor, a growth in the brain that can be either benign, which means non-cancerous, or malignant, which means that it is cancer
cerebral aneurysm, which is an abnormally widened area in an artery
fracture of the skull or neck
seizure disorder, or epilepsy
- stroke, which is brain damage that results 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 radiologist and the assistants operate the equipment. A nurse checks the person's vital signs, such as the heart rate and blood pressure, during the exam.
The radiologist must choose an artery where he or she can insert the catheter, most often the artery in the right groin, called the femoral artery. First, the skin in the groin area is numbed with a local anesthetic. Once the skin is numb, a small needle is inserted through the skin and into the artery. The radiologist 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 in place in the artery, it is 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 dye called a contrast agent is used to make the arteries more visible. The contrast agent is injected into the catheter and enters the arteries. This allows the arteries to be clearly seen. 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 radiologist can see the arteries clearly during the test.
Usually, several pictures are taken of the arteries filled with contrast agent from different angles and positions. Most often, several injections of the contrast agent are needed. The standard test will typically take less than an hour. In more complex cases, the exam may last for several hours. In some cases, the radiologist may see an abnormality during the test that can be corrected during the exam. 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 exam 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.
The healthcare professional will also review the person's medical and surgical history. He or she may ask whether the person:
takes medicines that thin the blood, such as aspirin or warfarin
has a bleeding tendency or any blood disorders
the person has any problem with or disease that affects the kidneys
- 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 for 6 to 8 hours before the test. Dentures, eyeglasses, and jewelry, such as a necklace or earrings, should be removed before the exam. 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:
allergic reactions to the contrast agent used
bleeding in the groin
heart attack, which occurs in less than 1% of cases
irregular heartbeats, called arrhythmias
stroke, which occurs in less than 1% of cases
If procedures are done during the exam, such as angioplasty, additional risks are involved. These will be discussed by the healthcare professional 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 radiologist who performs the test is usually the one who reviews the results. This involves looking at the pictures taken during the exam to check for any abnormalities. The healthcare professionals will use the results of this test to help decide the next course of action or a treatment plan.
Diagnostic Imaging, Reference and Review, by Ralph Weissleder (1998)
Handbook of Interventional Radiology and Angiography, Second Edition, by Myron Wojtowycz (1995)