Magnetic Resonance Imaging (MRI)

  • What is magnetic resonance imaging (MRI)

    MRI Brain and Knee - Example Image Axial MRI image of the brain (left) and sagittal MRI image of the knee (right). Magnetic resonance imaging (MRI) is a diagnostic imaging procedure that uses a powerful magnet, radiofrequencies and a computer to produce detailed images of the body’s organs and structures.

    The MRI machine looks like a small tunnel. The exam table moves through the opening of the tunnel. The machine makes cross-sectional images of the body, most often referred to as slices. Just imagine looking at a piece of bread from the middle of the loaf — that's what an MRI machine can do. It’s useful to see tissues anywhere in the body that otherwise may only be seen through surgery.

  • What should you do prior to the exam?

    There are different preparations to follow according to exactly what type of MRI scan your child is having. If your child

    • will not be sedated, there are no special preparations to follow.
    • Will be sedated for the exam, please follow the sedation preparation guidelines. Sedation is required for all children up to 8 years old.
    • Will be having an MRI Cholangiogram, then your child may have nothing to eat or drink four hours prior to the exam time. If your child is also being sedated for this exam, please follow the sedation guidelines.

    If your child has a noted allergy to radiographic contrast, additional preparations may be necessary.

    Dress your child comfortably, in clothes that are easily removed (sweat clothes, t-shirts). Your child may be given a gown to change into for the MRI, if required.

    If you have copies of your child's previous imaging studies from another institution, please bring them for comparison.

  • MRI safety precautions

    MRI does not pose any risks unless your child has any kind of implanted metal objects or devices in her body. For this reason, your child will screened to ensure both of you are safe to enter the magnetic field.

    All implants or devices must be approved by the MRI technologists and radiologists before entering the magnetic field. For efficiency, please bring the following information about your child's device with you:

    • Name of manufacturer
    • Date of placement
    • Name of device and composition (composition may not be listed but we can research it if needed)

    The following are not allowed into the CHOP MRI:

    • Defibrillators (IAED)
    • Greenfield filters
    • Pacemakers
    • Women who are pregnant (1st trimester)
    • Transdermal medication patches

    The following must be evaluated:

    • Bullets
    • Clamps
    • Clips
    • Cochlear Implants
    • Coils
    • Pins
    • Pregnancy
    • Screws
    • Shrapnel
    • Tattoos

    The following require special care before and after entering the MRI field:

    • IV fluids
    • PCA pumps
    • Programmable VP shunts
    • Vagal nerve stimulators

    All jewelry and metal (zippers, snaps) must be removed prior to entering the scanner room.

    Note: Only one parent or guardian will be allowed to accompany the child into the scanner room; other arrangements should be made for siblings. The parent or guardian accompanying the child to their MRI must be safety screened before entering the scanner room.

    Parents or guardians who are pregnant or may be pregnant will not be permitted to accompany their child during the MRI scan. Please make sure that there is someone else available to be with the child during the scan, if needed.

  • What should you and your child expect during the exam?
    • If your child is receiving contrast or sedation, we will bring you to a room for the pre-MRI work-up. We will place an IV in your child’s hand, arm or foot. Your child may feel a little pinch.
    • Once in the MRI control room, the technologist will ask why the MRI is being performed, will explain the scan to both you and your child, and will repeat the safety screening process.
    • You and your child will then enter the MRI scanning room with the technologist. The room may feel cold, so it’s a good idea to dress in layers.
    • You will be asked to sit near the scanner. You may bring something to read.
    • The technologist will help to position your child on the MRI table according to the type of scan she is having. While many children are positioned on their backs, some scans require children to lie on their stomach or side, head first or feet first.
    • The scan can be quite loud, so you and your child will be given ear plugs to help block out some of the noise.
    • Once your child is comfortable on the table, a red light will come on to help align her body to the correct position for the scan. Your child will then be moved into the tunnel of the MRI scanner. Depending on her position, your child may not be able to see you or talk with you.
    • After the technologist leaves the scanning room, the MRI will begin. The MRI scanner makes many sequences of loud noises, each of which may sound somewhat different.

    There will be a brief pause after each sequence. The technologist may give your child directions or prompts through a speaker. Your child will be able to speak to the technologist through the speaker.

    The technologist will ask your child to hold very still during the scan. Any type of movement during the MRI will make the images appear blurry, so the scan may have to be repeated. This will make the test take longer.

    Your child will not feel the magnetic field from the MRI scan, but may become uncomfortable from holding still. The MRI scan can take from 30 minutes to one hour for each body part being examined. While some patients do not require sedation for their MRI, others may benefit from emotional and/or medicinal support. Remember, sedation is required for all children under 8. Regardless of your child’s needs, the MRI team is there to help her get through the experience in the best way possible.

    If you’d like, our child life specialists will help you prepare and support your child during the procedure. We can also arrange to have a child life specialist at your child's appointment to explain the procedure in developmentally appropriate ways and to help your child better cope with the stress of the hospital experience.

  • What should you do after the exam?

    If your child received contrast, give your child plenty to drink during the day.

    If your child received sedation, follow any instructions given by the sedation nurses.

  • Test results

    The images from your child's exam are interpreted on the same day and a report sent to your physician's office.

    Your physician may call us at 215-590-2584 with questions about the report.