In vivo measurements of body protein based on the determination of nitrogen by prompt γ analysis

Abstract

Measurement of nitrogen in the human body gives a measure of total protein in the body. Nitrogen (N) may be measured in vivo by a nuclear technique in which the characteristic nitrogen γ rays emitted after capture of neutrons are detected and counted. The accuracy (as determined by comparison of the measurement of nitrogen in a pig by nuclear and chemical methods) is better than 10%. The reproducibility is r = 0.68) with height squared; for malnourished patients there is again a good correlation (r = 0.81) but the regression line for patients is approximately 34% below that for the volunteers consistent with their depleted state.