Physical Basis of Nuclear Magnetic Resonance Imaging

NMR imaging is based on the ability to induce and monitor resonance of the magnetic moment of nuclei in the presence of magnetic fields. By the use of magnetic fields whose strength varies with position, it is possible to define both the location and concentration of resonant nuclei, and, thereby to create images that reflect their distribution in tissue. Hydrogen, because it is the most sensitive of the stable nuclei to NMR and because it is also the most abundant nucleus in the body, is ideally suited for NMR imaging.