Scintillation detection with a gaseous photomultiplier for Compton imaging with liquidxenon

We report on the development of a liquid-xenon time-projection chamber, designed to validate a new medical imaging concept named ¿3¿ imaging¿. The advantages of detection gamma-induced scintillation light with a gaseous photomultiplier (GPM) operating in cryogenic mode are discussed; first results are presented.