POSITRON EMISSION TOMOGRAPHY (PET) TIMING CALIBRATION USING COINCIDENCES INVOLVING HIGH-ENERGY CASCADE GAMMA FROM PROMPT-GAMMA POSITRON EMITTERS

Timing calibration of a positron emission tomography (PET) imaging device (2) uses a radioactive source (20) comprising a positron-emitting radioisotope having a decay path including emission of two oppositely directed 511 keV gamma rays and a cascade gamma ray at a cascade gamma ray energy. A timestamped radiation detection event data set acquired from the radioactive source by the PET imaging device is processed using energy window filtering (32) and time window filtering (36) to generate a coincidence data set (40, 42, 44) including event pairs (40) each consisting of two coincident 511 keV events and cascade event pairs (42) or triplets (44) each consisting of at least one coincident 511 keV event and a coincident cascade event at the cascade gamma ray energy. A timing calibration (12) is generated using the coincidence data set. The timing calibration comprises offset times for PET detectors of the PET imaging device.