Magnetic resonance imaging is a method of imaging of the body that allows the organs to be viewed in 'slices'.
The body part to be scanned is enclosed by the magnetic coil, which affects the various tissue planes, allowing the viewer to 'see' the soft tissues.
The radiologist has to look at a series of two-dimensional visual 'slices' and interpret them in three dimensions.
MRI uses magnetic fields, not radiation
Magnetic Resonance Imaging (MRI) Scans resemble an X-ray but radiation is not used. Instead the limb is placed inside a magnetic coil, and the alignment of cellular charge to the magnet allows an interpretation to be made by computer as to the structure, and to some extent composition, of the body tissues.
Magnetic resonance imaging of the knee. Hash TW. Sports Health. 2013 Jan;5(1):78-107. doi: 10.1177/1941738112468416.
Magnetic resonance imaging of the knee: An overview and update of conventional and state of the art imaging. Nacey NC, Geeslin MG, Miller GW, Pierce JL. J Magn Reson Imaging. 2017 May;45(5):1257-1275. doi: 10.1002/jmri.25620. Epub 2017 Feb 17.