The Feasibility of in vivo Neutron Activation Analysis of Total Body Calcium and Other Elements of Body Composition

Abstract

Measurements of the 7-rays emitted from human cadavers and phantoms after exposure to relatively low levels of fast neutrons show that several elements of body composition can be determined by this procedure. These elements include Ca, Na, Cl, N2 and p. The determination of total body Ca is one of the most important applications of this method. The results of this study show that the Ca content in a man can be measured to an accuracy of [plus or minus] 8%, and that a change of 2% or more in the Ca content in the same person over a period of time can be detected. These results can be obtained with neutrons produced at a cyclotron and with radiation doses to the subject of 0 - 1 rad or less. A sensitive whole-body counter for measuring the 7-rays is described.