Nuclear magnetic resonance technology for medical studies

Common pharmaceuticals alter tissue proton NMR relaxation properties

Differences in the tissue properties of water are the basis for the detailed anatomic visualization of internal body structures produced by NMR imaging. Physiological and pathological events have the potential to alter proton nuclear magnetic resonance relaxation properties through changes in water environment. In this study, the parenteral injection of pharmaceuticals produced significant changes (12-21%) in proton NMR relaxation times in tissues of treated rats. The extent of relaxation time change was both tissue specific and drug specific. Therefore, the effects of common pharmaceuticals should be considered in the interpretation of T1- and T2-weighted NMR images.

[Recent developments in technics of nuclear magnetic resonance imaging]

Three main aspects of presently developed nuclear magnetic resonance imaging techniques are pointed out in this short review: first, the importance of Fourier transform as reconstruction technique is recalled; secondly, the problem of the choice of the magnetic field value is raised and third, new trends in magnetic imaging are noticed such as the use of nuclei other than hydrogen or the improvement of phase contrast methods.

Computers in dental radiography: a scenario for the future

The recent emergence of cost-effective computing power makes it possible to integrate sophisticated data-sampling and image-interpretation techniques into dental radiography for the first time. A prototype system is being developed to permit clinical information expressed in three dimensions--plus time--to be made visible almost instantly. The associated X-ray dose for a complete three-dimensional survey of a selected dental region is predicted to be less than that required for a single conventional periapical radiograph exposed on D-speed film.