MRA; Angiography - magnetic resonance DefinitionMagnetic resonance angiography (MRA) is an MRI exam of the blood vessels. Unlike traditional angiography that involves placing a tube (catheter) into the body, MRA is noninvasive. How the Test is PerformedYou may be asked to wear a hospital gown. You can also wear clothing without metal fasteners (such as sweatpants and a t-shirt). Certain types of metal can cause blurry images. You will lie on a narrow table, which slides into a large tunnel-shaped scanner. Some exams require a special dye (contrast). Most often, the dye is given before the test through a vein (IV) in your hand or forearm. The dye helps the radiologist see certain areas more clearly. During the MRI, the person who operates the machine will watch you from another room. The test may take 1 hour or more. How to Prepare for the TestYou may be asked not to eat or drink anything for 4 to 6 hours before the scan. Tell your health care provider if you are afraid of close spaces (have claustrophobia). You may be given a medicine to help you feel sleepy and less anxious. Your provider may suggest an "open" MRI. In an open MRI, the machine is not as close to the body. Before the test, tell your provider if you have:
Because the MRI contains strong magnets, metal objects are not allowed into the room with the MRI scanner. Avoid carrying items such as:
How the Test will FeelAn MRA exam causes no pain. If you have problems lying still or are very nervous, you may be given a medicine (sedative) to relax you. Moving too much can blur images and cause errors. The table may be hard or cold, but you can ask for a blanket or pillow. The machine produces loud thumping and humming noises when turned on. You can wear ear plugs to help reduce the noise. An intercom in the room allows you to speak to someone at any time. Some scanners have televisions and special headphones that you can use to help the time pass. There is no recovery time, unless you were given a medicine to relax. Why the Test is PerformedMRA is used to look at the blood vessels in all parts of the body. The test may be done of the head, heart, abdomen, lungs, kidneys, and legs. It may be used to diagnose or evaluate conditions such as:
Normal ResultsA normal result means the blood vessels do not show any signs of narrowing or blockage. What Abnormal Results MeanAn abnormal result suggests a problem with one or more blood vessels. This may suggest:
RisksMRA is generally safe. It uses no radiation. To date, no side effects from the magnetic fields and radio waves have been reported. The most common type of contrast used contains gadolinium. It is very safe. Allergic reactions to the substance rarely occur. However, gadolinium can be harmful to people with kidney problems who require dialysis. If you have kidney problems, please tell your provider before the test. The strong magnetic fields created during an MRI can cause heart pacemakers and other implants to not work as well. They can also cause a piece of metal inside your body to move or shift. ReferencesCarpenter JP, Litt H, Gowda M. Magnetic resonance imaging and arteriography. In: Sidawy AN, Perler BA, eds. Rutherford's Vascular Surgery and Endovascular Therapy. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 30. Kwong RY. Cardiovascular magnetic resonance imaging. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 19. | |
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Review Date: 5/10/2024 Reviewed By: Neil Grossman, MD, Saint Vincent Radiological Associates, Framingham, MA. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited. | |
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MRI scans
