What is magnetic resonance imaging?
Magnetic resonance imaging (MRI) is an exam that uses strong magnetic fields and radio waves to produce images of organs and internal structures. MRI provides different information than can be obtained using X-ray, ultrasound, or computed tomography (CT). For example, an MRI of the knee can provide detailed images of ligaments and cartilage which are not visible on other exams.
An MRI scanner is shaped like a tunnel with a motorized table that slides in and out of the tube. While your child is inside the scanner, information from many different angles will be collected. This information is sent to a computer, which reconstructs all the individual "snapshots" into one or multiple cross-sectional images (slices) of the internal organs and tissues.
For some MRI exams we will give your child a magnetically active material through an intravenous line (IV). This is called a contrast agent and it is used to make the organs and structures more visible in the images we create. We may require that your child is sedated during the exam to ensure that your child lies still.
How can I help my child prepare for the exam?
If your child will be having an MRI with contrast, or if your child will be sedated for the exam, you will need to follow some preparation instructions. A nurse will provide you with instructions prior to your appointment.
On the day of the exam your child should wear comfortable clothes. Please leave all jewelry, hair clips, and other metal objects at home. If you have copies of prior exams, bring them with you to the appointment. Please make childcare arrangements for siblings as they will not be allowed into the exam room.
Please note that if you are pregnant, you will not be allowed in the room during the exam and may wish to make arrangements to have someone else be with your child.
What will happen during the test?
Your child may be asked to change into a gown when you arrive for the MRI. You will be allowed to accompany your child to the exam room.
If your child will be receiving contrast or sedation, a nurse will insert an IV, usually into their hand or arm. A technologist will then take you and your child to the MRI exam room and position your child on the table. The technologist will leave the room to perform the scan, but they will be able to see, hear, and speak with your child at all times.
During the exam, the table will slide into the scanner. A red light may shine on your child’s body, which helps ensure that they are properly positioned. MRI scanners make loud buzzing and clicking sounds, and we will give your child ear plugs to make them more comfortable.
The MRI takes from 30 minutes to one hour to complete.
What can I do to help my child feel comfortable during the exam?
Young children sometimes find the MRI scanner a bit frightening. You can remain with your child in the imaging area during the exam to offer comfort and reassurance. We can also arrange to have a child life specialist at the appointment to help your child better cope with the stress of the procedure.
MRI does not use radiation, and there are no known harmful side-effects associated with temporary exposure to the strong magnetic field used by MRI scanners.
If your child has an implanted metal object or device, the strong magnetic field could pose a risk. We will screen you and your child several times throughout the process to make sure you are safe to enter the magnetic field.
Many devices have been tested and determined to be safe for MRI. If your child has an implantable device, pins or screws, tattoos, shrapnel, or other non-removable metal objects in their body, our radiologists and technologists will evaluate the object and determine whether there is a safety issue.
After the exam
After the exam most children can immediately resume their normal activities. If your child was sedated, we will ask you to wait in the imaging area after the exam until they are reasonably alert.
A radiologist will analyze the MRI images and will share the results with the doctor who requested the exam. Your child’s doctor will then discuss the results with you.