Autoradiography of alpha- and beta-emitters using a charged-particle imaging system

A newly developed charged-particle imaging system was applied to rapid measurements of the distribution of alpha- and beta-emitters. The imaging system consists of a ZnS(Ag) screen, two tapered fibers, an image intensifier, and a Polaroid film. The image obtained with the system shows very good quality, namely, a spatial resolution of more than 6 line pairs (lp)/mm and a distortion of less than 2.5%. As the system is capable of detecting each alpha-particle separately, the distribution of alpha-emitters can be quantitatively determined. The autoradiograms of the sections of mice with beta-emitters administered can be obtained with an exposure time of only 2 min compared with 2 weeks by a conventional technique.