Fig. 1

Schematic diagram of the system developed for ¹⁵O-oxygen PET, which consists of a radiosynthesizer installed in a cyclotron room, and an inhalation controller and an inhalation/scavenging unit installed in a PET room. An additional radio water generator (RWG) unit is installed in parallel to this system. MFC, RD, and FM indicate a mass flow controller, a radioactive detector, and a flow meter, respectively. F and R denote values for flow and radioactivity concentrations, respectively. All radio-detectors are calibrated to a standard dose calibrator (Model CRC712, CAPINTEC, Florham Park, NJ, USA). Two sets of gas chromatographs (GCs) are placed in the inhalation controller. See text