What Is Magnetic Resonance Angiogram?

  • Medical Editor: William C. Shiel Jr., MD, FACP, FACR
    William C. Shiel Jr., MD, FACP, FACR

    William C. Shiel Jr., MD, FACP, FACR

    Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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Do you have any info regarding a procedure called an MRA - magnetic resonance angiogram, which would be used to look for any possible aneurysms in the head, etc.?

Doctor's response

The magnetic resonance angiogram, or MRA, is a noninvasive test that has demonstrated usefulness in defining the anatomy of blood vessels of certain size in the head and neck. MRA serves as a complement to traditional MRI scanning in evaluation of the brain and neck.

Conventional angiograms, whereby contrast material is injected through a catheter into the blood vessels of the head and neck, are the gold standard (most accurate) for determining the anatomy of these vessels. The advantages of MRA is that it is faster and easier (it does not involve the catheters, contrast material, and risks of angiograms). Another advantage is that MRA also gives an image of the tissue of the brain.

MRA is a general term that refers to various imaging techniques that are used to visualize the blood vessels by using magnetic resonance (MR) signal changes that are affected by changes in the flow of blood caused by changes in the shape of the blood vessels.

MRA can be used to detect small ballooning of the blood vessels (aneurysms) as small as 4 millimeters in diameter. Smaller aneurysms can require an angiogram for detection. The sensitivity of MRA in detecting aneurysms can be affected by bleeding within the brain and the location of the aneurysms within the brain.

MRA can also detect abnormal design (malformations), and atherosclerosis of blood vessels within the brain. Atherosclerosis of the carotid arteries of the neck can be visualized with MRA.

MRA does not have significant application for the detection or definition of cancer of the brain.

Thank you for your question.

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Reviewed on 1/11/2018