Simplification of simultaneous measurement of the total body content of five elements using only one 14 MeV neutron generator.

Measurement of body composition by total body in vivo neutron activation analysis is a valuable tool for clinical research but use of this technique has been largely restricted to medical units near existing neutron irradiation facilities. A facility for total body in vivo neutron activation analysis was purpose-built at low cost and has performed well. The methods of scanned bilateral neutron irradiation and scanned bilateral measurement of induced activity have been subject to continuous development. It has been found possible to dispense with one of the original complement of two 14 MeV neutron generators, without significantly impairing measurement of any of the elements for which the system was designed (phosphorus, calcium, nitrogen, chlorine and sodium). Thus a hospital department with access to a whole-body counter capable of measuring total body 40K can now extend its investigation of body composition to these five important elements at a cost of 75 m2 of floor space and less than 30 000 pounds.