Magnetic resonance imaging (MRI)

What is an MRI scanner and how does it work?

An MRI scanner is a large, tube-shaped magnet that provides a strong magnetic field around your child. A radiofrequency coil is placed over the part of your child's body that needs to be imaged. The magnetic field, along with applied radiofrequency waves, temporarily alters the alignment of hydrogen protons found in water molecules within the body. Computers construct the images based on the radiofrequency signals emitted by the protons.

Why might an MRI be needed?

MRI is often used to obtain specific diagnostic information not already provided by other imaging technologies such as computed tomography (CT), nuclear medicine, ultrasound and x-ray.

How should I prepare my child for the MRI scan?

• It is helpful to give your child a simple explanation as to why she needs an MRI and assure her that you will be with her for the entire time.
• You may want to bring your child's favorite book, toy or comforting object to use while you wait.
• If your child will be using the video goggles or listening to music, you can bring a favorite DVD or an iPod from home. The department also has a collection of movies available.
• During the scan the machine makes noises but will not hurt your child.

For abdominal scans, your child may be asked to refrain from eating or drinking for four to six hours and will be required to drink a solution upon arrival before the scan begins. It is important that you follow all instructions or the scan may need to be rescheduled.

What should I expect when I bring my child to the hospital?

When you arrive, please go to the MRI radiology check-in desk on the second floor of the main hospital in Boston or the first floor check-in desk at our Waltham facility. An ambulatory service representative will check your child in and verify her registration information.

We will give you a safety screening questionnaire to fill out for your child:

• This form will ensure that your child can be safely imaged in MRI.
• If you plan to accompany your child into the scanner room, you must also fill out a form for yourself.
• Please bring supporting documentation of MRI safety if you or your child have had any surgical implants or devices. Delays may result if devices need to be researched. Some exams may need to be cancelled if required MRI safety information cannot be obtained.

When your paperwork is complete:

• A member of the MRI team will come out to the waiting room to bring you and your child to the screening room. As part of the screening, your child may be weighed or measured.
• Your child will change into hospital pajamas.
• You and your child will need to remove all metal objects. Lockers are available for locking up any valuables.

Your child may be able to watch a movie or listen to music during the scan. If you brought a movie or iPod from home, you can give it to the MRI team member. Otherwise, your child can choose a movie or music from the department's collection.

What happens during the MRI scan?

When your child is brought into the scanner room:

• The MRI technologist positions your child on the scanning bed. The inside of an MRI machine looks like a tunnel. It is necessary for the body part that will be scanned to be in the center of the scanner, so the technologist will move the scanner bed into the tunnel until it is appropriately positioned.
• We give your child earplugs to protect his or her ears because the MRI machine makes loud pulsing or knocking sounds.
• The technologist asks your child to lie still while the scan is in progress.

An MRI technologist will perform your child's scan. You may stay in the scanner room with your child unless the MRI safety screening questionnaire indicates that it is not safe for you to do so. You will also be given earplugs to wear in the room.

Sometimes, patients receive a substance called gadolinium during the scan, which is needed to provide additional information about some parts of the body. Gadolinium is given through an injection into your child's vein.

MRI scans consist of several sequences of a few minutes' duration each that, in total, take anywhere from 20 to 90 minutes, depending on the information required by the radiologist and your physician. We will give you a more specific time frame before the scan begins.

What does an MRI sound like?

Sound 1
Sound 2
Sound 3
Sound 4
MR makes music!

What happens after the MRI scan?

When the MRI scan is done, your child will be ready to go home. The radiologist will review the images and create a report of the findings and diagnosis for your referring doctor.

How do I learn the results of the MRI scan?

The radiologist's report will be sent to the physician who requested the exam and your child's doctor will then discuss the results with you. If there is a finding on the scan that requires urgent attention, we will contact the referring physician in order to discuss the findings and plan further treatment.