Detection of pion‐induced radioactivity by autoradiography and positron emission tomography (PET)

Abstract

An autoradiographic technique incorporating a new imaging system was used to detect pion‐induced radioactivity in Plexiglass and the results were compared with aluminium activation and PET imaging. The activity distribution in the region of the pion‐stopping peak was similar in all three cases. Another large signal in the entrance region due to in‐flight interactions [¹²C(π−,π−n)¹¹C] was detected by autoradiography and by PET but was not reflected in the aluminium activation measurements. This new technique is capable of defining the stopping region in phantoms with a better resolution than PET scanning and is useful as a complementary technique to other methods of pion dosimetry.