The invention provides a positron emission tomography photography (PET) system and its information processing method and a computer readable medium, capable of increasing the compatibility relevant with the system operation. The information processing method is a method of processing positron emission tomography (PET) information obtained from a PET detector having a plurality of detector regions, each detector region has at least one detector module and a corresponding regional collector, the method including the steps of receiving PET event information for a single PET event, the PET event information including energy information and crystal position information of the single PET event; receiving non-detector event information; generating an event list that includes a PET event entry, the PET event entry including a fine time stamp, the energy information, and the crystal position information, and a non-detector event entry that includes the received non-detector event information; and transmitting the generated event list to a computer for off-line processing.
Positron emission tomography photography system and its information processing method