A magnetic resonance imaging (MRI) scan can be critical to planning surgery, radiation therapy or treating head and neck disorders. Although it is not as precise in evaluating bony structures, MRI gives superior detail of soft tissues like nerves, the spinal cord and the brain.
MRI is better than CT in assessing or describing soft tissue masses such as tumors.
MRIs can also be used to find and monitor injuries or disorders that affect the nerves including brain and spinal cord tumors and tissue abnormalities in persons with eye or inner ear diseases.
Before an MRI, it is important to remove any clothing, wigs, hearing aids, dentures or jewelry that may contain metal or electronics. If you have metal or electronic devices such as artificial joints or heart valves, a pacemaker or rods, plates or screws holding bones in place, be sure to tell the technician. Metal may interfere with the magnetic field used to create an MRI image and can cause a safety hazard. The magnetic field may damage electronic items.
Do not have an MRI scan if you have an implantable cardioverter defibrillator or pacemaker. The strong magnetic field created by the MRI unit may interfere with how these devices work. If you are or think you may be pregnant, be sure to tell the technician before having an MRI.
The MRI machine is a cylinder-shaped magnet in which you must lie totally still for short periods. You will lie down on a sliding table with your head in a brace. The table then slides into the unit. An MRI takes 15 minutes to an hour, depending on the part of the body being studied.
While MRIs are a relatively new technology, advances are continuing to be made. Some of these advances include:
- Spectroscopic MRIs, which measure certain metabolites in the body, helping doctors diagnose and treat conditions such as cancer or infections
- Diffusion MRIs, which create an image based on the microscopic movement of water in the spaces outside the cells; and
- Stronger magnets that allow for more detail and faster imaging than conventional MRI machines.