[Nuclear magnetic resonance studies on brain edema--time course of 1H-NMR relaxation times (author's transl)].

1. The state of water in normal and edematous brain tissue was studied by measurement of proton longitudinal (T1) and transverse (T2) relaxation times using pulsed nuclear magnetic resonance (NMR) technique. 2. In control rats, T1 and T2 of water showed one component, which was more fast in white matter. Those values displayed 1.07-1.18 sec. of T1 and 75-76 msec. of T2. 3. When rat brain was injured by cold, T1 was observed to become more longer (1.18-1.27 sec.), and T2 was observed to be separated into two components, the faster T2 (45-50 msec.) and slower T2 (100-105 msec.), in body gray and white matter of the injured side. 4. In triethyltin (TET) induced brain edema, elongation of T1 (1.2 sec.) and remarkable separation of T2, faster T2 (75 msec.) and slower T2 (400-450 msec.), were observed in white matter. 5. In both cold and TET induced edema, slower T2 fraction is suggested to be the extracellular space and faster T2 fraction, intracellular. 6. T2 changes precede the water content changes in cold injury, and parallel in TET induced edema. Those changes of relaxation times are reversible. 7. T2 changes of water is more sensitive than the T1 for the detection of production and disappearance of brain edema. 8. These results disclose the dynamic movements of water during the course of brain edema and offered significant information of the clinical application of NMR-CT.