MRA stands for Magnetic Resonance Angiography. It is an MRI technique that specifically evaluates vessels such as arteries. Brain MRAs evaluate the vessels of the brain to look for aneurysms, vascular malformations such as AVMs, narrowing and blockage of the vessels of the brain, among others. (Read about MRI scans and MRI scans of the brain.)
Brain
MRAs are typically ordered for many different symptoms
to exclude an aneurysm or vascular malformation, or search for a source of bleed. They are also used during the evaluation of stroke to detect blockages and narrowing of the arteries that feed the brain. Below are a few common diagnoses that brain
MRAs can pick up.
Aneurysm -
Aneurysms are ballooning of vessels that risk rupturing. If blood leaks
from the aneurysm patients describe the headache as a thunderclap and
sharp/shooting pains. Patients can also have stroke-like symptoms with
weakness, slurred speech and confusion. MRAs can detect most aneurysms though if the aneurysm is small or has collapsed, it may not be identified by this study.
AVM - AVM stands for arteriovenous malformation. This is essentially a nest of abnormal vessels which grows in the brain. The vessels of AVMs are like "varicose veins" with thin walls but are subjected to high pressure blood flow, so risk rupture, much like an aneurysm. They can also act like tumors in that if large enough they compress nearby brain tissue. AVMs can also form aneurysms in or near them. Patients will experience headaches, stroke-like symptoms or seizures.
Stroke - Also
known as a "brain attack", stroke refers to a blocked artery that
deprives a part of the brain of blood (and therefore oxygen). This part
of the brain loses it function and patients present with weakness,
slurred speech, difficulty walking and on occasion, headaches. MRAs evaluate the extent of atherosclerosis and can detect any significant blockages.
An MRA of the brain will evaluate:
Internal Carotid Arteries
The carotid vessels arise from the aorta in the chest and travel up the neck along both sides. The vessels splits in the neck with the "internal" segments feeding roughly the front 2/3 of brain tissue.
Basilar Artery
The basilar artery is made up by two vertebral arteries which arise from vessels in the chest and travel up along both sides of the neck near the spine. This vessel feeds the brain stem and approximately the back 1/3 of the brain.
Circle of Willis
This refers to the group of vessels that are at the base of the skull that feed the brain. These vessels are formed by branches of the internal carotids and the basilar artery. FYI brain MRA scans call also be called MRA COW (Circle of Willis).
Brain matter
The
white and gray matter of the brain are partially seen. Parts of the
pituitary gland, optic nerves and upper brain stem are also evaluated.
Your Brain MRA Scan
A brain MRA generally takes about 10 minutes or so to complete. If you are
going for one, wear loose comfortable clothing and remember to remove
all metal (jewelry, phones, rings, etc) before going into the MRI scan
room. This test is occasionally done with IV MRI contrast.
If you're insured, you may need to have your test authorized (approved) by your insurance company first. If you're uninsured and need to look up prices and buy an MRA scan of the brain, you can use our website to look up MRA scan costs and then purchase with your credit card.
Have you had a Brain MRA scan? What was it like? Please leave your comments below.