MR Angiography

What is MR angiography?

Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical conditions. Angiography in conjunction with magnetic resonance imaging (MRI) produces pictures of major blood vessels throughout the body.

In magnetic resonance angiography (MRA), a powerful magnetic field, radio waves and a computer produce the detailed images. During an MRA exam, radio waves are directed at the area of your body being studied. In the magnetic field, protons in your body change their position, producing signals that are detected by the coils. A computer then processes the signals and generates a series of images each of which shows a thin slice of the body. The computer compiles the images into a three-dimensional representation of the body, which can be studied from many different angles on a computer monitor.

What are some common uses of the procedure?

MRA is used to examine blood vessels in key areas of the body. Physicians use the procedure to identify and detect diseases of the brain, kidneys, pelvis, legs, lungs, heart and neck.

How should I prepare for the procedure?

You may be asked to wear a gown during the exam or you may be allowed to wear your own clothing if it is loose-fitting and has no metal fasteners. Some examinations may require the patient to swallow contrast material or receive an injection of contrast. If you have claustrophobia or anxiety, you may want to ask your physician for a prescription for a mild sedative. Metal and electronic objects are not allowed in the exam room because they can interfere with the magnetic field. These items include jewelry, watches, credit cards, hearing aids, pins, hairpins, metal zippers, metallic items, removable dental work, pens, pocketknives and eyeglasses.

What can I expect during this procedure?

You will be positioned on the moveable examination table. Straps and bolsters may be used to help you stay still and maintain the correct position during imaging. Small devices that contain coils capable of sending and receiving radio waves may be placed around or adjacent to the area of the body being studied. If a contrast material will be used in the exam, an IV line will be inserted into a vein in your hand or arm. A saline solution will drip through the IV to prevent blockage of the IV line until the contrast material is injected. The contract material will be injected into the IV after an initial series of scans. When the contrast material is injected, it is normal to feel coolness and a flushing for a minute or two. Additional series of images will be taken following the injection, however, you will be able to relax between imaging sequences.

It is normal for the area of your body being imaged to feel slightly warm, but if it bothers you, notify the technologist. It is important that you remain perfectly still while the images are being recorded, which is typically only a few seconds to a few minutes at a time. You will know when images are being recorded because you will hear tapping or thumping sounds when the coils that create the magnetic field are turned on. You will be alone in the exam room during the exam, however, the technologist will be able to see, hear and speak with you at all times using a two-way intercom.

When the examination is completed, you may be asked to wait until the technologist checks the images in case additional images are needed. Your intravenous line will be removed. MRA exams generally include multiple runs (sequences), some of which may last several minutes. The entire examination is usually completed within one hour.

What can I expect after the procedure?

If you have not been sedated, no recovery period is necessary. You may resume your usual activities and normal diet immediately after the exam. A few patients experience side effects from the contrast material, including nausea and local pain. Very rarely, patients are allergic to the contrast material and experience hives and itchy eyes.