Magnetic Resonance Imaging (MRI)
Prior to Magnetic Resonance Imaging (MRI), the patient is instructed to remove any metal objects (e.g. jewelry, hairpins) and change into a gown. During the scan, the patient lies comfortably on a motorized table inside the scanner surrounded by huge powerful magnets.
The technician observes the patient throughout the exam through large windows to the adjacent control room. The technician converses with the patient by means of an intercom. Typically, the test takes up to an hour to complete.
Magnetic resonance imaging does not require the patient to change bodily positions. Instead the patient is instructed to be still. Magnetic resonance imaging generates images in the sagittal (left/right), coronal (front/back), axial (head/toe), and oblique (slanted) planes without moving the patient. Certain MRI studies utilize a contrast medium to enhance particular body structures.
Magnetic resonance imaging produces vivid and complex images in 256 levels of gray that characterizes the relationship between vertebrae, intervertebral discs, spinal cord, and nerve roots. It is a valuable diagnostic and pre-surgical planning tool, and replaces some invasive diagnostic procedures.
If the patient's MRI scan is to include a contrast medium, known allergies to intravenous dyes should be discussed with the referring physician prior to the test.
Patients should tell their physician if their body contains any ferromagnetic objects such as shrapnel, a pacemaker, or aneurysm clips. These patients cannot undergo magnetic resonance imaging.. Ferromagnetic objects are attracted by the MRI's powerful magnet.