Development of crosshair light sharing PET detector with TOF and DOI capabilities using fast LGSO scintillator

Eiji Yoshida, Fujino Obata, Kei Kamada, Akira Yoshikawa, Taiga Yamaya

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Objective. Time-of-flight (TOF) and depth-of-interaction (DOI) are well recognized as important information to improve PET image quality. Since such information types are not correlated, many TOF-DOI detectors have been developed but there are only a few reports of high-resolution detectors (e.g. 1.5mmresolution) for brain PET systems. Based on the DOI detector, which enables singleended readout by optically coupling a pair of crystals and having a loop structure, we have developed the crosshair light sharing (CLS) PET detector that optically couples the four-loop structure, consisting of quadrisected crystals comparable in size to a photo-sensor, to four photo-sensors in close proximity arranged in a windmill shape. Even as a high-resolution detector, the CLS PET detector could obtain both TOF and DOI information. The coincidence resolving time (CRT) of the CLS PET detector needs to be further improved, however, for application to the brain PET system. Recently, a fast LGSO crystal was developed which has advantages in detection efficiency and CRT compared to theGFAG crystal. In this work, we developed the CLS PET detector using the fast LGSO crystal for the TOF-DOI brain PET system. Approach. The crystals were each 1.45 × 1.45 × 15mm3 and all surfaces were chemically etched. The CLS PET detector consisted of a 14 × 14 crystal array optically coupled to an 8 × 8MPPCarray. Main results. The fast LGSO array provided 10.1% energy resolution at 511 keV, 4.7mmDOI resolution at 662 keV, and 293 ps CRT with the energy window of 440-620 keV. Significance. The developed CLS PET detector has 290% higher coincidence sensitivity, 30% better energy resolution, and 32% better time resolution compared to our previous CLS PET detector.

Original languageEnglish
Article number225003
JournalPhysics in medicine and biology
Issue number22
Publication statusPublished - 2021 Nov 21


  • DOI
  • Detector
  • PET
  • TOF

ASJC Scopus subject areas

  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging


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