A low-count reconstruction algorithm for Compton-based prompt gamma imaging

Hsuan Ming Huang, Chih Chieh Liu, Meei Ling Jan, Ming Wei Lee

Research output: Contribution to journalJournal Article peer-review

5 Scopus citations


The Compton camera is an imaging device which has been proposed to detect prompt gammas (PGs) produced by proton-nuclear interactions within tissue during proton beam irradiation. Compton-based PG imaging has been developed to verify proton ranges because PG rays, particularly characteristic ones, have strong correlations with the distribution of the proton dose. However, accurate image reconstruction from characteristic PGs is challenging because the detector efficiency and resolution are generally low. Our previous study showed that point spread functions can be incorporated into the reconstruction process to improve image resolution. In this study, we proposed a low-count reconstruction algorithm to improve the image quality of a characteristic PG emission by pooling information from other characteristic PG emissions. PGs were simulated from a proton beam irradiated on a water phantom, and a two-stage Compton camera was used for PG detection. The results show that the image quality of the reconstructed characteristic PG emission is improved with our proposed method in contrast to the standard reconstruction method using events from only one characteristic PG emission. For the 4.44 MeV PG rays, both methods can be used to predict the positions of the peak and the distal falloff with a mean accuracy of 2 mm. Moreover, only the proposed method can improve the estimated positions of the peak and the distal falloff of 5.25 MeV PG rays, and a mean accuracy of 2 mm can be reached.

Original languageEnglish
Article number085013
JournalPhysics in Medicine and Biology
Issue number8
StatePublished - 19 04 2018

Bibliographical note

Publisher Copyright:
© 2018 Institute of Physics and Engineering in Medicine.


  • Compton camera
  • low count
  • prompt gamma ray
  • proton therapy


Dive into the research topics of 'A low-count reconstruction algorithm for Compton-based prompt gamma imaging'. Together they form a unique fingerprint.

Cite this