MRI (Magnetic Resonance Imaging)

Massachusetts General Hospital Imaging provides MRI exams on the Mass General main campus and at convenient community locations. No matter which facility you come to, our staff places priority on making your journey through the imaging process comfortable, safe, and successful. All images are read by a radiologist with specialty expertise in the area of the body being studied.

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. Hear the sound of an MRI machine.
• MRI does not use X-ray radiation.
• MRI excels at imaging soft tissue; it is used to look at internal organs, the brain and spinal cord, and breasts, for example.
• Exams typically take 45 minutes.
• 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.
• The technologist performing your exam will be nearby and able to talk to you throughout 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 (we cannot provide such medication).
• Every exam is interpreted by a radiologist with specialty expertise in the specific area of the body under study. A specialist is capable of seeing and understanding subtle things due to advanced training and singular focus.
• We use the latest technology, including high-resolution 3T scanners. On-staff physicists and engineers ensure that our machines remain in top condition.

What should I expect BEFORE my MRI exam?

Medications: It is important for you to keep to your regular medication schedule. Just let our staff know what medications you have taken prior to your MRI Exam.

Food and drink: You may eat or drink anything you like before a typical MRI test. If you are having your abdomen scanned it may be necessary for you to fast for a few hours before the test and to drink some contrast (please see the "Contrast Medium" section below) when you arrive for your test. An MRI staff member will call you the day before your test and give you any instructions you need. At that time, we can also tell you approximately how long we anticipate your test will take.

When to arrive: You should arrive 30 minutes before your scheduled appointment. This allows time for you to complete any necessary paperwork, change your clothes for your exam and answer questions from our technologist about your medical history before we start your scan.

What to wear: For all MRI scans, you most likely will change into a hospital gown. Our changing areas are private and there is a secure locker for your clothes. It is best, however, if you leave valuable items at home. If you are wearing anything metallic, such as jewelry, dentures, eyeglasses, or hearing aids that might interfere with the MRI scan, we will ask you to remove them. You should not have your credit cards in your pockets during the scan because the MRI magnet can affect the magnetic strip on the card. Patients who are having a brain / head scan should not wear make-up as some brands contain metal.

Intravenous preparation: Many of our patients receive a contrast agent intravenously during their MRI scan in order to give a clearer picture of the area being scanned. If your doctor has determined that this procedure will enhance your MRI scan results, the technologist will place an IV in your arm prior to your going into the scan. (Please see the "Contrast medium" section below.)

What will I experience DURING my MRI exam?

Scanning: Your technologist will bring you into the MRI scan room where you will lie down on the patient table. The technologist positions the part of your body to be scanned in the middle of the large cylindrical magnet. The scanner does not touch you, nor do you feel anything. Because the scanner does make a loud knocking noise when it takes the pictures, the technologist will offer you headphones to listen to music or earplugs to lessen the sound.

Hear the sound of an MRI machine

The technologist leaves the room, but is in full view and communication with you through the observation window in the adjoining room. There is also voice communication at all times through an intercom. It is important for you to lie very still, and at some points you may be asked to briefly hold your breath as the picture is taken.

Length of MRI exam: Each MRI scan is tailored to each patient's needs, so the scanning time varies. Often the exam will involve a preliminary scan, then an injection of contrast through the IV in your arm, followed by more scanning. After all of the images are taken, we may ask you to wait a few moments while the radiologist reviews all the images so we can be sure we have exactly what your doctor wants. You may then get dressed and leave.

Contrast medium: A contrast medium, or contrast agent, highlights your organs and blood vessels and helps the radiologist see them better. The contrast agents in use today carry a low risk of allergic reaction and cause little discomfort for most people. If you are over 60 or have kidney disease, diabetes, lupus, or multiple myeloma, you’ll need a blood test beforehand to make sure the contrast will be safe for you.

What should I expect AFTER my MRI exam?

Instructions: You have no restrictions after having a MRI exam and can go about your normal activities. To help eliminate the contrast medium from your body, remember to drink plenty of fluids.

Exam results: All MRI exams are read by a Mass General radiologist specialty trained in MR imaging and dedicated to the specific area of interest for your study.

Rapid results are essential not only for your peace of mind, but also for your physician to begin planning your treatment immediately, if necessary. After the scan has been read, the results are sent to your physician, who will discuss them with you.

MRI with Anesthesia: How to Prepare

This handout is available to give to patients ≥20 years to help them prepare for their MRI.

• How to Prepare for your MRI with Anesthesia

MRI with Anesthesia: How to Order

Use this tip sheet to order and schedule MRIs with anesthesia for patients≥20 years.

• Tip Sheet for Partners Providers
• Tip Sheet for Providers Outside of Partners

MRI in depth

What is an MRI exam?

Magnetic Resonance Imaging, or MRI, is a valuable, painless, diagnostic test that allows radiologists to see inside some areas of the body that cannot be seen using conventional X-rays. MRI produces a series of cross-sectional pictures. MRI technology has advanced so much in recent years that it has greatly altered treatment courses. Physicians can detect many conditions in earlier stages, greatly optimizing patient outcomes.

Mass General Imaging uses state-of-the-art MRI scanners to take pictures with very high resolution. These images give your physician important information in diagnosing your medical condition and planning a course of treatment.

Common uses

Areas of the body that may undergo an MRI scan include the head, chest, abdomen, vital organs, joints, spine or extremities such as hands, wrists, ankles, and feet. Our highly sophisticated scanners also have capability to diagnose diseases of blood vessels in the brain, neck, and body.

Safety

All of our equipment is maintained in top condition, meeting not only the standards set by the federal government, but also by those set by Mass General Hospital's health physicists.

MRI scanners do not use X-rays. Instead, they use a very strong magnet and radio frequency. Even so, it is important to tell the technologist if there is a chance you could be pregnant. There is no evidence that MRI is unsafe for a developing fetus; however, we are still careful in the use of MRI on pregnant patients.
Patients with any kind of metallic implant anywhere in their body should not have an MRI unless their physician is fully aware of the device and has approved the MRI procedure. Under no circumstances should a patient who has a pacemaker have an MRI.

We welcome pediatric patients at our imaging centers. Specific time slots are reserved for pediatric MRIs so that pediatric nurses and technologists can spend extra time with children and families. Our staff, trained in the care of pediatric patients, works closely with MassGeneral Hospital for Children.

Please tell the technologist if you are, or might be, pregnant. In certain cases you may not be able to have an MRI and will need to discuss alternatives with your doctor.

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