Water in brain edema. Observations by the pulsed nuclear magnetic resonance technique.

The state of water in three types of brain edema and in normal brain of the rat was studied by the pulsed nuclear magnetic resonance (NMR) technique. In cold-induced edema and in osmotic edema both in cortex and in white matter, the water protons have longer nuclear magnetic relaxation times than in normal brain. The observed changes correlate with the water content of the brain tissue. In triethyltin induced edema, no change was found for relaxation times in the cortex, whereas in the white matter, an additional fraction was observed with much longer relaxation times, attributable to fluid within the vesicles in the myelin sheaths. Since the NMR technique is non-destructive, it is potentially applicable in the living patient as a method for the detection of brain lesions that are accompanied with changes of brain water.