Magnetic resonance imaging (MRI), formerly referred to as magnetic resonance tomography (MRT) or, in chemistry nuclear magnetic resonance (NMR), is a non-invasive method used to render images of the inside of an object. It is primarily used in medical imaging to demonstrate pathological or other physiological alterations of living tissues. MRI also has uses outside of the medical field, such as detecting rock permeability to hydrocarbons and as a non-destructive testing method to characterize the quality of products such as produce and timber.

The scanners used in medicine cost approximately US$ 1 million per tesla (T) and have a typical field strength of 0.3 to 3 T, with several hundred thousand dollars paid per year just for maintenance.

Edson Zerati, MD