What Is Cardiac MRI?

Magnetic resonance imaging (MRI) is a safe, noninvasive test that creates detailed pictures of your organs and tissues. "Noninvasive" means that no surgery is done and no instruments are inserted into your body.

MRI uses radio waves, magnets, and a computer to create pictures of your organs and tissues. Unlike computed tomography (to-MOG-ra-fee) scans (also called CT scans) and standard x rays, MRI doesn't use ionizing radiation or carry any risk of causing cancer.

Cardiac MRI creates pictures of your heart as it's beating, producing both still and moving pictures of your heart and major blood vessels. Doctors use cardiac MRI to get pictures of the beating heart and to look at its structure and function. These pictures can help them decide how to treat people who have heart problems.

Cardiac MRI is a common test. It's used to diagnose and evaluate a number of diseases and conditions, including:

• Coronary heart disease, also called coronary artery disease
• Damage caused by a heart attack
• Heart failure
• Heart valve problems
• Congenital heart defects
• Pericarditis (a condition in which the membrane, or sac, around your heart is inflamed)
• Cardiac tumors

Cardiac MRI can help explain results from other tests, such as x rays and CT scans. Sometimes, cardiac MRI is used to avoid the need for invasive procedures or tests that use radiation (such as x rays) or dyes containing iodine (these dyes may be harmful to people who have kidney problems).

Often during cardiac MRI, a contrast agent is injected into a vein to highlight portions of the heart or blood vessels. This contrast agent often is used for people who are allergic to the dyes used in CT scanning.

People who have severe kidney or liver problems may not be able to have the contrast agent. As a result, they may have an MRI that doesn't use the substance (a noncontrast MRI).

Revised July 2009