Arteriovenous Malformation

Diagnosis

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Diagnosing an AVM usually begins with a thorough neurological exam by a neurologist. Depending on those results, the physician may request one or more tests. Imaging tests are conducted by radiologists who specialize in imaging the brain and nervous system, ensuring that each examination is performed and interpreted to the highest standard of quality. Mayo has an international reputation for high quality imaging and rapid results. In Mayo's efficient system, exams are interpreted almost immediately after the exam, and results available in Mayo's electronic record system within 24 hours.

Three main tests are used to diagnose AVMs:

CT scan and CTA
The CT scanner takes pictures of the brain using X-rays. Sometimes dye is injected through an IV 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 CT angiogram (CTA).

MRI and MRA
MRI, which creates images using a large magnet and radio waves, is even more sensitive than CT in showing AVM vessels. MRI also provides information about the exact location of the AVM, which is very important for treatment planning and risk assessment. Dye can also be injected to allow better visualization of the blood circulation in the brain (MRA).

Cerebral Arteriograpy
Cerebral arteriograpy (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.