Percent Body Water Measurement Using in vivo D2O Dilution and Deuteron Photodisintegration.

The measurements of percent body water, lean body mass, and body fat are generally associated with technical difficulties, safety limitations, and inherent accuracies. Using D2O dilution for this purpose is comparatively safe but has, in the past required quantification by relatively insensitive and laborious methods. A promising new approach to quantifying D2O in serum samples is based on the photodisintegration of the deuteron, in which a high energy gamma ray initiates the breakup of a deuterium nucleus into a proton and a neutron. The proton is stopped in the serum sample and is not detected. The emitted neutron, with higher probability of escape, is detected by standard procedures. The technique is amenable to automation, low D2O doses, and permits determination of percent body water, lean body mass, and body fat at even lowest echelon medical facilities.