If you have never had an MRI, you may have heard some information about the procedure that causes concern. Advertisements for open-air models for claustrophobic patients may cause you to wonder what exactly goes on inside the machine. However, the process is painless and non-invasive. Understanding what happens during the procedure might help you feel at ease while inside the tube.
Doctors use the MRI for a number of reasons: to evaluate the nature and extent of an injury to the knees, joints or spine, and to diagnose tumors, multiple sclerosis and strokes. Additionally, this type of imaging can be used to more accurately direct surgery. The MRI procedure is the best way for doctors to see what is going on inside your body without implementing surgery. However, it is usually only used when other imaging methods fail to provide sufficient information to confirm a diagnosis due to expense.
Preparing for the procedure is simple. If your doctor orders imaging tests, you will likely be asked to change into a gown. You will also have to remove all your jewelry and make sure no credit cards or anything metallic is on you person. This is because the machine uses magnets to create images. During the procedure, you will need to remain perfectly still. You may become bored while inside the machine. Prior to the procedure, talk to the doctor or nurse about bringing in a pair of headphones to listen to music during the process. If you are especially anxious, your doctor might prescribe a light sedative.
Once you are ready for the procedure, you will be pushed into the MRI tube for the image to be made. The tube contains a magnet capable of producing an incredibly strong, stable magnetic field. During the scan, the body’s hydrogen atoms line up in the direction of the magnetic field. The magnetic field runs down the center of the machine, so about half of the body’s hydrogen protons flock towards the head, and the other half orient towards the feet at a nearly one-to-one ratio. Next, a radio frequency pulse that targets hydrogen is applied. When the scan is directed to the part of the body that needs to be examined, those stray hydrogen atoms that did not orient to the head or the feet are forced by the pulse to spin in a particular direction. At the same time, three gradient magnets inside the main magnet and are switched on and off to alter the main magnetic field on a local level. This step allows the doctor to zero in on the area he or she needs to see. Finally, the hydrogen protons transmit data to a computer to create the image.
Understanding how an MRI works can ease some of the tension associated with lying still inside a small space for an hour or so. Discuss your concerns with your doctor or nurse to come up with a strategy that will make the procedure more comfortable for you.