Cardiac MRI (magnetic resonance imaging)

Massachusetts General Hospital Imaging provides cardiac MRI services in a caring environment using the latest technology, and every scan is interpreted by a cardiac-imaging specialist.

Cardiac MRI

Massachusetts General Hospital Imaging provides cardiac MRI services on the Mass General main campus. Our staff places priority on making your journey through the imaging process comfortable, safe, and successful. All images are read by a cardiac-imaging specialist.

Cardiac MRI overview

  • An MRI machine produces a strong magnetic field and radio waves. The atoms in your body respond to this energy in a certain way. The MRI detects this response and uses it to construct detailed images.
  • MRI does not use X-ray radiation.
  • A cardiac MRI is a special type of MR exam designed to look at the structure and function of the heart.
  • Exams take up to two hours, usually including 60 to 90 minutes in the MRI machine.
  • Many exams involve contrast—an injection that makes the images more vivid and informative.
  • If you are over 60 or have kidney disease, diabetes, lupus, or multiple myeloma, a blood test before your exam is necessary to make sure the contrast is safe for you.
  • Because of the strong magnet, we need to make absolutely sure you don’t have any metal objects with you. We also need to know details about any implants in your body.
  • We will attach electrodes to your chest to monitor your heart rate during the exam.
  • The technologist performing your exam will be nearby and able to see you and talk to you throughout the scan.
  • You will be asked to hold your breath for 10 to 18 seconds several times during the scan.
  • MRI exams require that you lie still in a confined space. Most people have no problem, but talk to your doctor if you are concerned. Your doctor may prescribe a sedative beforehand (we cannot provide such medication).
  • Every exam is interpreted by a cardiac-imaging specialist with additional expertise and advanced training in MRI.

Cardiac MRI in depth

What is cardiac MRI?

Cardiac MRI exams allow doctors to see the heart in motion in order to diagnose problems and plan proper treatments. In this case, the moving images show that the tip of the heart has been damaged by a heart attack and is not contracting normally

Cardiac MRI (magnetic resonance imaging) is an imaging test that uses a powerful magnetic field, radio waves and a computer to produce high quality still or moving pictures of structures inside the heart.

An advantage of MRI over other methods for imaging the body, such as CT (computed tomography) or Nuclear Medicine, is that no X-rays or radioactivity are used to create the pictures. Women should always inform their physician or technologist if there is any possibility that they are pregnant. Because the risks of an MRI exam to the baby are unknown, pregnant women should not have this exam unless the potential benefit from the MRI is assumed to outweigh the potential risks.

MRI can provide information about the anatomy, function, and damage that the heart has sustained, depending on the indication for your study. MRI may also be used to assess the blood vessels in the body.

Cardiac MRI offers superior images of the heart muscle itself, when compared to other imaging techniques such as echocardiography (cardiac ultrasound) or CT (x-ray computed tomography). Cardiac MRI is usually performed to offer complementary information that other cannot provide.

What should I expect BEFORE my cardiac MRI?

  • When to arrive: Please arrive at least 60 minutes prior to your appointment time. Your early arrival will help to ensure that we are able to perform the test efficiently and safely. We will also ask you a series of questions that will determine whether or not it is safe for you to undergo the MRI.

    Specifically, you will be asked if you have any metal objects inside of your body. Some examples include: Pacemakers, heart valves, aneurysm repairs, and injuries in which metal could have lodged within the body, especially into your eyes. We may also order additional tests or request further information from you or your doctor concerning any metal implants you may have.
  • Sedation: If you are claustrophobic, you may ask your doctor to schedule your MRI with sedation (a medication to help you relax).
  • What to wear: You will be asked to change into a hospital gown and to remove all metal objects, such as pens, eyeglasses, jewelry, hairpins, dentures, credit cards or dental bridgework. We recommend that you leave metal accessory items at home. A locker and key will be provided to you to store clothing and valuables.
  • Preparation: An intravenous catheter will be inserted in your arm for intravenous contrast injection. If you have a known contrast allergy or had a reaction to contrast dye, please tell your physician and technologist prior to the exam. Electrocardiogram leads will be placed on your chest in order to monitor your heartbeat. Before beginning the exam, you will be coached in a method to hold your breath. You will be asked to hold your breath a few times for 10-18 seconds.
  • Scheduling: Cardiac MRI is an advanced examination, requiring close physician supervision. Most cardiac MRIs are therefore scheduled during the work week, when we have access to the fastest MRI scanners and radiologists with advanced training who can directly supervise the exam.

What should I expect DURING my cardiac MRI?

  • Scanning: The MRI machine is a tube with a 3-foot-wide opening in the center. You will be asked to lie on a table that slides into the central opening. Using a speaker and headphone system, we will be able to communicate with you throughout the exam. It is very important for you to stay as still as possible because movements can create blurring of the images. The scanner will make a loud knocking noise every time you will be asked to hold your breath. Earplugs will be given to you to muffle the noise. The length of the scan varies depending on what kind of information your doctor has requested, but typically is approximately 60 minutes.

What should I expect AFTER my cardiac MRI?

  • Recovery: 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.

    It is recommended that nursing mothers not breastfeed for 36 to 48 hours after an MRI with a contrast material.
  • Exam results: Typically, the results of any examination will be available to your doctor within 24 hours. Your doctor will communicate the results of your study directly to you.

Imaging specialists, focused on you

Each radiologist at Mass General Imaging is a specialist in a particular area of the body. Department of Radiology Chairman Emeritus James H. Thrall, MD, explains how patients benefit from the additional specialty training our physicians have completed.


Discover the Imaging patient experience

Mass General offers specialty-trained radiologists, leading-edge technology and a caring staff that's committed to patient safety and comfort.


Imaging experts, focused on you

Every scan at Mass General Imaging is read by a radiologist with specialty training in the area of the body being studied.

Discover the Corrigan Minehan Heart Center patient experience

Our approach to patient care brings together a team of cardiac specialists who create a personalized treatment plan for each patient.