In vivo elemental partition analysis using fast neutrons. A tool for testing the efficacy of new clinical interventions.

The nutritional status of patients can be evaluated by monitoring changes in body composition, including depletion of protein and muscle; distribution of adipose tissue; and changes in hydration status, and bone or cell mass. Fast neutron activation (for N and P) and neutron inelastic scattering (for C and O) are used to assess in vivo elements characteristic of specific body compartments. Nonbone phosphorus for muscle is measured by the 31P(n,alpha)28Al reaction, and nitrogen for protein via the (n,2n) fast neutron reaction.