title: [Comparison between CT and NMR images. Physical aspects].
abstract: On the basis of simple physical considerations, parameters influencing the computer tomograph (CT) and nuclear magnetic resonance (NMR) pictures are compared. In the case of the CT, only X-ray tube voltage and radiation intensity (i.e. dose to the patient) can be altered. Changing the X-ray tube voltage alone produces no special diagnostic advantages, unless the method is supplemented, for a specific body region, by separate determination of the "Hounsfield number" in Compton or photoelectric numbers. However, the method is associated with relatively major measurement and evaluation problems. A survey of the principles of the NMR technique is followed by a brief explanation of the so-called "tissue parameters" and "measurement parameters" which influence picture quality in the NMR technique. Despite certain advantages it can scarcely be expected that the NMR technique will replace the CT technique in the next few years: it is very probable, however, that a shift to specific examinations will occur in the case of the latter.
mesh_terms: D006801:Humans; D008159:Lumbar Vertebrae / Q000473:pathology; D009682:Magnetic Resonance Spectroscopy / Q000592:standards*; D014057:Tomography, X-Ray Computed / Q000592:standards*
vernacular_title: Vergleich zwischen CT- und NMR-Bildgebung. Physikalische Aspekte.