A combined time-of-flight and depth-of-interaction detector for total-body positron emission tomography

Eric Berg, Emilie Roncali, Maciej Kapusta, Junwei Du, Simon R Cherry

Research output: Contribution to journalArticlepeer-review

32 Scopus citations


Purpose: In support of a project to build a total-body PET scanner with an axial field-of-view of 2 m, the authors are developing simple, cost-effective block detectors with combined time-of-flight (TOF) and depth-of-interaction (DOI) capabilities. Methods: This work focuses on investigating the potential of phosphor-coated crystals with conventional PMT-based block detector readout to provide DOI information while preserving timing resolution. The authors explored a variety of phosphor-coating configurations with single crystals and crystal arrays. Several pulse shape discrimination techniques were investigated, including decay time, delayed charge integration (DCI), and average signal shapes. Results: Pulse shape discrimination based on DCI provided the lowest DOI positioning error: 2 mm DOI positioning error was obtained with single phosphor-coated crystals while 33.5 mm DOI error was measured with the block detector module. Minimal timing resolution degradation was observed with single phosphor-coated crystals compared to uncoated crystals, and a timing resolution of 442 ps was obtained with phosphor-coated crystals in the block detector compared to 404 ps without phosphor coating. Flood maps showed a slight degradation in crystal resolvability with phosphor-coated crystals; however, all crystals could be resolved. Energy resolution was degraded by 3%7% with phosphor-coated crystals compared to uncoated crystals. Conclusions: These results demonstrate the feasibility of obtaining TOFDOI capabilities with simple block detector readout using phosphor-coated crystals.

Original languageEnglish (US)
Pages (from-to)939-950
Number of pages12
JournalMedical Physics
Issue number2
StatePublished - Feb 1 2016


  • depth-of-interaction (DOI)
  • phosphor coating
  • positron emission tomography (PET)
  • scintillator
  • time-of-flight (TOF)

ASJC Scopus subject areas

  • Biophysics
  • Radiology Nuclear Medicine and imaging


Dive into the research topics of 'A combined time-of-flight and depth-of-interaction detector for total-body positron emission tomography'. Together they form a unique fingerprint.

Cite this