title: NMR in medicine.
abstract: Nuclear magnetic resonance (NMR) offers a powerful new probe of the body's internal anatomy and function. The technique utilizes a combination of static and radio frequency (RF) magnetic fields to excite a weak resonant magnetic field emission from various selected naturally abundant nuclei in the body such as hydrogen (1H), phosphorus (31P) and carbon (13C). The emissions can be spatially encoded by application of magnetic field gradients, to enable the generation of high resolution anatomical images which reflect the nuclear density distribution, and/or spatial variations in the molecular level and chemical environments of the nuclei as measured by the NMR relaxation times and chemical shifts. 1H NMR relaxation time images are proving useful for the detection of a wide spectrum of disorders, whilst spatially localized 31P and 13C NMR chemical shift spectra measure directly the metabolic status of living tissue. A qualitative explanation of NMR, NMR imaging, relaxation times, and chemical shifts is presented, and the historical development, future of the technology, and its range of applications explored.
mesh_terms: D000818:Animals; D002986:Clinical Trials as Topic; D004574:Electromagnetic Fields; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000639:trends; D051379:Mice; D012063:Relaxation; D013997:Time Factors