Cardiac Magnetic Resonance Imaging (MRI)

Cardiac magnetic resonance imaging (MRI) is a medical imaging technique that utilizes a powerful magnetic field, radio waves and a computer to create detailed pictures of the beating heart. The resulting images can help a physician evaluate the structure and function of the heart muscle, identify tissue damage caused by a heart attack or determine the cause of heart failure. 

Conditions Diagnosed 

A physician may order a cardiac magnetic resonance imaging test to investigate the cause of chest pain, heart palpitations and other symptoms that may suggest: 

  • Atherosclerosis – Hardening of the arteries due to a buildup of cholesterol plaque 
  • Cardiomyopathy – Thickening and weakening of the heart muscle 
  • Congenital heart disease – A heart defect, such as a hole in the wall between the two lower chambers, that was present at birth 
  • Heart failure – Weakening of the heart muscle 
  • Heart valve disease – A damaged heart valve that inhibits blood flow 
  • A cardiac tumor – A mass on the outer or inner surface of the heart 

Procedure Details 

During a cardiac magnetic resonance imaging scan, the patient lies on a moveable examination table. Electrocardiogram (ECG) leads may be placed on the patient’s chest to help the MRI machine synchronize the image acquisition with his or her heartbeat, and a small pulse monitor will be placed on his or her finger. Additionally, a respiratory gating belt may be placed around the patient’s abdomen to monitor his or her breathing rate so the scan can be adjusted if necessary.  

Sometimes, a contrast material is used with cardiac MRI. If so, a technician will place an intravenous (IV) line into a vein in the patient’s arm or hand that will be used to deliver the dye. 

The exam table will then move into the tunnel of the MRI scanner. The patient will be asked to take and hold a deep breath for short periods during the examination. The technician will perform the test while working at a computer outside of the room, but the technician will be able to see the patient from a window and communicate with him or her via an intercom at all times. MRI exams generally include multiple runs (sequences) through the scanner, some of which may last several minutes. The entire process takes approximately 90 minutes. 

What to Expect 

Unlike X-ray and computed tomography (CT) exams, MRI does not involve radiation exposure. Instead, a magnetic field is created by passing an electrical current through wire coils in an MRI scanner. These coils send and receive radio waves, which are used to realign hydrogen atoms naturally found within the body. As the hydrogen atoms return to their normal alignment, they emit energy. The MRI scanner captures this energy and uses it to create a series of highly detailed images, each one showing a thin slice of the tissue being examined. 


When evaluating images produced with cardiac magnetic resonance imaging technology, a physician can generally distinguish between healthy and damaged tissues with greater accuracy than when evaluating images created with X-ray, computed tomography (CT) or ultrasound technology. 

Tampa General Hospital’s Heart & Vascular Institute is proud to offer the latest diagnostic technologies, including cardiac magnetic resonance imaging, for heart disease and vascular conditions.