Nuclear Magnetic Resonance
Magnetic Resonance Imaging Scan
This Magnetic Resonance Imaging (MRI) scan through a normal adult head shows the brain, airways, and soft tissues of the face. MRI has become a valuable diagnostic tool, and is especially effective at imaging the brain, head, and neck.
Nuclear Magnetic Resonance or NMR, technique developed separately in 1945 by American physicists Felix Bloch and Edward Mills Purcell for the spectroscopic analysis of substances. In NMR, a substance is placed in a strong magnetic field that affects the spin of the atomic nuclei of certain isotopes of common elements. A radio wave passes through the substance then reorients these nuclei. When the wave is turned off, the nuclei release a pulse of energy that provides data on the molecular structure of the substance and that can be transformed into an image by computer techniques. In the early 1980s, NMR also became a diagnostic tool for obtaining more precise images of tissues within the human body than are possible with CAT scans or ultrasonics (see Radiology). In its medical applications, NMR is now more commonly referred to as magnetic resonance imaging (MRI). MRI is unsurpassed as an imaging technique for scans of the brain, head, and neck.