Contrary to popular belief, there are no X-rays used in an MRI. In the MRI scanner, hydrogen atoms in the patient’s body are exposed to a strong magnetic field. A radiofrequency pulse is then used. When the pulse is turned off, the atoms give off energy signals that are measured by a computer. The computer processes these signals to create detailed images of human anatomy.

MRI technology is known for producing extremely detailed images. An MRI is better at capturing the small features between similar structures. For instance, it can easily show the difference between the white matter and gray matter in your brain and spinal cord, whereas a CT scan is not as detailed. Because of this, an MRI will be chosen when looking for small structures or when images of finer detail are needed.

Since MRI is non-invasive, the exam is painless. Depending on what specific issue they are looking for, your MRI may use a contrast agent to better see a part of your anatomy. If this is the case, the MRT will give you an injection prior to or during the exam. The MRT will ask you to lay down on the table. The table will move you slowly in and out of the MRI scanner. Sometimes, but not often, people feel a little dizzy when the MRI table moves into and out of position. Once you are in the correct spot, you will hear a loud knocking or buzzing sound throughout your exam. Your MRT will provide you with hearing protection. The exam room may be cold, to keep the machine at a correct temperature. Your MRT can provide you a blanket if you get cold. Exam times vary, however, your MRT is in the control room and is watching you through a glass window the whole time. You can also talk to them through an intercom if you need to. 

When you arrive for your MRI exam, you will be required to provide a health and surgical history. Anyone with surgical implants, including metallic or electronic implants should notify the MRT. They will consult with the radiologist or sometimes your family doctor, to determine if you can be safely scanned. Many modern surgical implants can be scanned in the machine but may require planning ahead of time. Therefore it is important to share your health and surgical history with your MRT.  To help with future scans, be sure to ask your surgeon (or a family member’s surgeon) what exactly was implanted during the surgery/procedure or if you have an implant card.  This information can save time when an urgent MRI is needed. 

Gadolinium is a contrast dye used during some MRI exams.  The clear solution is injected into your hand or arm with an intravenous (IV) line. It interacts with the MRI’s magnetic field, creating distinctions between organs and vessels. Contrast improves the visibility of certain diseases, allowing the radiologist to interpret and be certain of your diagnosis.  

Gadolinium contrast is used every day and is considered very safe. If you develop sensitivities or react to it, it will likely happen immediately. MRTs are trained to start IVs, inject the gadolinium, and manage any reactions that you may have. If you have had previous sensitivities or reactions to gadolinium, you should inform the MRT who will consult with the Radiologist. 

A typical exam lasts less than 60 minutes but can be as short as 15 minutes or as long as 2 hours. You should always allow extra time in case the exam lasts longer than expected. For first timers undergoing an MRI, the shape and loud noises of the MRI machine can be intimidating. Depending on the scan required, your whole body may go into the MRI scanner. The body part being imaged needs to be in the center of the machine to produce the best image. If you feel nervous, let the MRT know, and they will try to work with you.  There are many tools and resources that an MRT can use to help you get through the exam.  

During the scan, you will always be in contact with an MRT. Even when they are not in the MRI room, you will be able to talk to them by intercom.  You can ask the MRT to talk to you between scans to let you know how long the next one will be.  A cooling fan can be turned on or up to give you the feeling of more air. The MRT is always able to see you through a large patient viewing window, but will not be able to hear you during the loud sounds. A rubber ball may be given to you to squeeze in case you have trouble during a scan. This will get their attention.  In some cases, a friend or family member may stay in the scan room with you during your exam. Please consult your MRI facility for their policy on this matter.