Volume 2 Supplement 1

Proceedings of the 4th PSMR Conference on PET/MR and SPECT/MR

Open Access

A theoretical comparison of position estimation methods for determining the interaction position of gamma rays in monolithic scintillators

  • Matteo Galasso1,
  • Cristian Borrazzo1, 2 and
  • Andrea Fabbri1
EJNMMI Physics20152(Suppl 1):A36


Published: 18 May 2015


Monte Carlo SimulationReconstruction AlgorithmMaximum Likelihood MethodActive ElementGamma Camera

We report the development of a mathematical model, based on the estimation theory, for the performance analysis of different gamma-ray interaction position estimation methods applied to gamma cameras based on monolithic scintillators. The gamma camera performance is expressed in terms of bias and spatial resolution. We propose a method to investigate performances of various detection system configurations, used in recent papers, when different image reconstruction algorithms are used. The results are obtained for the whole field of view, with a computational time five order of magnitude lower than a Monte Carlo simulation. We developed a mathematical model for four estimation methods: the classical Center of Gravity method (Anger Logic), an enhanced Center of Gravity method, a Mean Square Error fitting method and the Maximum Likelihood method. Moreover, those models can be used to investigate edge effects and performance of a detector with an arbitrary pattern of active elements and dead areas, in order to study systems with more multianode PMTs or SiPM array modules. The bias and spatial resolution results obtained with those mathematical model were compared with the ones obtained from Monte Carlo simulations, made with GEANT4, showing a very good agreement for all the methods.

Authors’ Affiliations

Department of Molecular Medicine, University of Rome "La Sapienza", Rome, Italy
INFN Sezione Roma III, Rome, Italy


© Galasso et al; licensee Springer. 2015

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.