Tests and diagnosisBy Mayo Clinic staff
Diagnosing a brain AVM usually begins with a thorough medical exam by a doctor who specializes in conditions of the brain and nervous system (neurologist). Depending on those results, the doctor may request one or more tests. Imaging tests are usually conducted by radiologists who specialize in imaging the brain and nervous system.
Three main tests are used to diagnose brain AVMs:
- Cerebral arteriography. Cerebral arteriography (also known as cerebral angiography) is the most detailed test and the best way to diagnose an AVM. The test reveals the location and characteristics of the feeding arteries and draining veins. A thin tube is inserted into an artery in the groin. This tube is threaded up toward the brain to the blood vessels. Dye is injected into the blood vessels of the brain, and X-rays are taken.
- Computerized tomography (CT). A computerized tomography (CT) scan takes pictures of the brain using X-rays. Sometimes dye is injected through an intravenous tube in a vein so that the arteries feeding the AVM and the veins draining the AVM can be viewed in greater detail. This is called a computerized tomography angiogram (CTA).
- Magnetic resonance imaging (MRI). Magnetic resonance imaging (MRI), more sensitive than CT in showing the AVM, creates images using a large magnet and radio waves. MRI also provides information about the exact location of the malformation, which is very important for determining treatment options. Dye can also be injected to better see the blood circulation in the brain. This is called a magnetic resonance angiogram (MRA).
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