Magnetic Resonance Imaging (MRI)
MRI uses radio waves and a strong magnetic field to create clear and detailed pictures of internal organs and tissues. Since MRI does not use X-rays, no radiation exposure is involved. In MRI, radio waves are directed at the body’s protons within the magnetic field. The protons become “excited”, and as they “relax” and emit radio signals, they are then processed by a computer to create an image. MRI is very useful in diagnosing diseases in all parts of the body including cancer, vascular and heart disease, liver and bile duct abnormalities, stroke, other neurological diseases and joint and musculoskeletal disorders. An MRI exam usually will take anywhere from 30-50 minutes and consists of several imaging series. Most studies will require a small intravenous injection of an MRI contrast agent that usually contains the metal Gadolinium. MRI contrast does not contain iodine, an element that is used in other contrast agents for X-rays or CT scans. Thousands of MRI’s are conducted each year, and technology has improved this system so vastly that a doctor can image abnormalities in a matter of seconds.
Not everyone can be scanned using this process. Very large people, those who wear pacemakers, those who may have metal fragments in their eyes from prior injury, those with recent metal implants or some surgical clips and those who are claustrophobic often cannot be safely scanned.