Tomography and elemental analysis of biological systems.

The various forms of tomography, expressed as transmission and emission modes using gamma rays and neutrons, are generally discussed in terms of providing information nondestructively about the distribution of elemental composition in a plane through an object. The combination of the principles of tomography with neutron activation analysis is the basis for neutron-induced gamma-ray emission tomography. The concept of detection limit in induced gamma-ray emission tomography, as proposed, incorporates a further factor that is a measure of the quality of the image produced. A specific example is given for the elemental analysis and imaging of a bone specimen.