During Magnetic Resonance Imaging the patient is placed inside a giant magnet and is exposed to radio waves. 聽Hydrogen nuclei in the body behave as tiny magnets and orient themselves with the external magnetic field. 聽They are forced out of alignment by radio waves and the time it takes for them to realign gives clues to disease processes. 聽The term 鈥渘uclear鈥� referred to the nucleus of hydrogen atoms and had nothing to do with radioactivity. 聽Public fear of radiation forced the name change from 鈥淣uclear Magnetic Resonance Imaging鈥� to 鈥淢agnetic Resonance Imaging (MRI).鈥�
