Ultrahigh resolution small animal PET systems require small pixel size scintillators. We developed an ultrahigh resolution small animal PET system using fine LYSO pixels, which were 0.32 mm×0.5 mm×5.0 mm. The LYSO pixels were combined into a 22×15 matrix with a 0.1 mm thick BaSO4 reflector between them. The LYSO block was 9.24 mm×9.0 mm×5 mm, and it was optically coupled to a 4×4 through silicon via silicon photomultiplier (TSV Si-PM) array that has smaller gaps between channels with a 1-mm thick light guide. We made eight Si-PM-based block detectors and arranged them octagonally to form a PET detector ring. At the center, the spatial resolution of the developed PET system, which was reconstructed by filtered back projection (FBP), was 0.6-mm FWHM. The sensitivity at the axial center was 0.5%. The peak noise equivalent count rate (NECR) was 12.5 k cps. We obtained high resolution images of phantoms and small animals with the developed PET system. With these results, we conclude that a high resolution PET system is possible with 0.32 mm pixel LYSO scintillators.
|Number of pages
|Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
|Published - 2016 Nov 11
- Ultrahigh resolution