Cost-Effective Depth-Encoding Methods for Time-of-Flight PET Scanners

Positron Emission Tomography (PET) is a non-invasive medical imaging technique with a unique utility toward the diagnosis and location of cancer, and with growing applications to the study of neurodegenerative diseases. In order to improve position resolution and reduce parallax error during image reconstruction, state-of-the-art scanners feature both time-of-flight (TOF) capability and depth-of-interaction (DOI) sensitivity. Using Monte Carlo simulations in Geant4 and benchtop experiments, we have explored low-cost methods for achieving DOI sensitivity in lutetium–yttrium oxyorthosilicate (LYSO) PET scanners based on light-sharing between scintillator pixels. We have also explored the impact that LYSO's surface polish has on its TOF and DOI resolutions.