What is an magnetic resonance imaging test?
Magnetic resonance imaging (MRI) uses magnetic fields and radio waves to scan the body’s internal organs and structures. It produces a series of pictures called slices or cross sections. When viewed all together, these provide a comprehensive view of the area of your child's body that is under study.
The MRI test offers greater clarity and much more detail than a conventional X-ray and provides more information than ultrasound or computed tomography (CT). An MRI of the knee, for example, can provide views of the ligaments and cartilage which will not show up on other tests.
Our pediatric radiologists use MRI to evaluate the following areas:
- The brain
- Organs in the chest and abdomen
- The pelvic area--the bladder and the reproductive organs
- Blood vessels and lymph nodes
- Vascular anomalies
- Bones and joints
MRI scans may also be ordered to help physicians:
- Diagnose tumors and monitor the effects of treatment
- Identify diseases and abnormalities of the liver, bile ducts, and pancreas
- Determine the causes and extent of inflammatory bowel disease; heart problems (such as congenital heart disease); and malformations/inflammation of the blood vessels.
How does the test work?
An MRI machine is made up of a scanner shaped like a tube. Your child will lie down on a motorized table that moves through the scanner.
The scanner then collects images from many different angles and sends them to a computer. A special software program puts all these slices or cross-sections together to produce highly accurate picture of your child’s internal organs and tissues.
Some MRI tests require a contrast agent to help illuminate a certain part of the body. If needed, your child will receive this agent intravenously (IV).
How can I prepare my child for the MRI?
We recommend that our young patients wear comfortable clothing to the exam. Some may be asked to change into a gown just before the test.
During the MRI, it is very important that your child lie still. This insures an accurate result. When the child finds this challenging for any reason, sedation may be administered intravenously (IV).
If your child is having an MRI with contrast, we will give the contrast agent intravenously (IV), usually through the hand or arm. Occasionally, a child will develop itching or hives. This reaction to the contrast agent can easily be relieved with medication. In extremely rare instances, a child may become light-headed or have difficulty breathing. If so, please alert the nurse immediately, for these may be signs of a more serious allergic reaction.
What happens next?
You will then proceed into the MRI exam room. You child will be positioned on the table, and asked to lie on his or her back. For scans of certain areas, it may be necessary to lie on the side or stomach.
Once your child is positioned, the table will slide inside the scanner. A red light may shine, helping us to ensure that body is properly positioned.
Since MRI scanners make loud buzzing and clicking sounds, we will give your child ear plugs.
The MRI technician performs the scan in an adjoining room, but is able to see, hear and speak to your child through the whole procedure.
The MRI exam may take from 30 minutes to one hour to complete.
Can I stay with my child during this test?
Because young children sometimes find the MRI scanner intimidating, we encourage you to be present during the test to offer comfort and reassurance. A child life specialist can be present as well, to help your child stay calm during the procedure.
Are there any risks?
MRI does not use the type of radiation used in x-rays and CT scans. Further, there are no known harmful side effects associated with temporary exposure to the magnetic field used in this exam. As noted, there is a slight risk that a child will develop an allergic reaction to the contrast agent.
What happens after the test?
After the exam most children can resume their normal activities right away. If your child was sedated, however, we will ask you to stay with us until your child is reasonably alert.
A radiologist will analyze the images and your child’s physician doctor will explain the results.