A new method for calculating the distribution of radioactivity in man measured with a whole-body counter.

A whole-body counter with a scanning bed and two opposite (antero-posterior) probes was used to obtain profiles of count rates of radioactivity held in the whole body. The distribution of the activity in the patient was calculated by solving an overdetermined system (more equations than unknowns) of linear equations with the Chebyshev method, the least-squares method, and an iterative method. The iterative method gave the best results, especially in the case of distributions with peaks of radioactivity. Some in-vivo applications of the method are presented.