What is MRI?

Magnetic Resonance Imaging (MRI), or nuclear magnetic resonance imaging (NMRI), is primarily a medical imaging technique most commonly used in radiology to visualize the internal structure and function of the body. MRI provides much greater contrast between the different soft tissues of the body. Radio frequency (RF) fields are used to systematically alter the alignment of this magnetization, causing the hydrogen nuclei to produce a rotating magnetic field detectable by the scanner. This signal can be manipulated by additional magnetic fields to build up enough information to construct an image of the body. MRI use a powerful magnetic field to align the nuclear magnetization of (usually) hydrogen atoms in water in the body. In very simple terms, MRI uses an enormously powerful electromagnet to align all the unbound protons in your body with the poles of the magnet. The protons are then 'plucked' or 'struck', either by radio waves or other magnetic fields.