| abstract |
The arrangement imaging a body through gamma radiation comprising the steps of detecting, within each fixed time period of a succession of fixed time periods at a plurality of locations impinged by the gamma radiation, electric charge levels corresponding to photoelectric events; counting within each fixed period only those charge levels at each location which are greater than a predetermined threshold level, and adding the counted charge levels for the succession of fixed time periods, whereby a distinct image of the body may be produced therefrom. |