Prior to the advent of open MRI, all magnetic resonance imaging tests took place in equipment similar to that shown in the diagram. Patients are placed on a table and slid into a narrow, cylindrical tube where the images are taken.

Conventional MRI can be difficult for people with claustrophobia, for children and for people who are physically large. Open MRI can solve this problem. With an open MRI system, the patient lies on an imaging table with free space on all sides. Electromagnetic waves are emitted from a large, round mechanism suspended just above the patients. Like the traditional MRI, an open MRI test is also painless and does not use ionizing radiation.

Restrictions

MRI procedures use strong magnetic fields, and people with pacemakers, ferromagnetic surgical clips in the brain and some other surgical implants should not undergo the procedure. Similarly, patients with artificial heart valves, metallic ear and cochlear implants, defibrillator wires and chemotherapy or insulin pumps may not be able to have MRI scanning. The patient's primary care physician will consult with the MRI physicians and personnel to determine whether or not MRI is a viable approach.