title: Comparative analysis of iterative reconstruction algorithms with resolution recovery for cardiac SPECT studies. A multi-center phantom study.
abstract: BACKGROUND
  This investigation used image data generated by a physical phantom over a wide range of count statistics to evaluate the effectiveness of several of the newer commercially available SPECT reconstruction iterative algorithms (IRR) in improving perfusion defect contrast and spatial resolution, while controlling image noise.
  
  
  METHODS
  A cardiac phantom was imaged using four different gamma cameras over a wide range of counts statistics (from 6 to 0.8 Mcounts). Images were reconstructed with FBP, OSEM, and the IRR available on site. IRR were applied without corrections (IRR NC), with attenuation correction (IRR AC), scatter correction (IRR SC), and attenuation + scatter corrections (IRR SCAC). Four image performance indices related to spatial resolution, contrast, and image noise were analyzed.
  
  
  RESULTS
  IRR NC always determined significant improvements in all indices in comparison to FBP or OSEM. Improvements were emphasized with IRR SC and IRR SCAC. Count reduction from 6 to 1.5 Mcounts did not impair the performances of any of the considered indices.
  
  
  CONCLUSIONS
  This is the first study comparing the relative performance of different, commercially available, IRR software, over a wide range of count statistics; the additional effect of scatter and attenuation corrections, alone or in combination, was also evaluated. Our results confirm that IRR algorithms produce substantial benefits with respect to conventional FBP or OSEM reconstruction methods, as assessed through different figures of merit, in particular when SC and/or SCAC are also included.
authors.affiliation: Department of Nuclear Medicine, S. Maugeri Foundation, IRCCS, Scientific Institute of Veruno, Veruno, NO, Italy.
authors.forename: Orazio
authors.initials: O
authors.lastname: Zoccarato
authors.forename: Camilla
authors.initials: C
authors.lastname: Scabbio
authors.forename: Elena
authors.initials: E
authors.lastname: De Ponti
authors.forename: Roberta
authors.initials: R
authors.lastname: Matheoud
authors.forename: Lucia
authors.initials: L
authors.lastname: Leva
authors.forename: Sabrina
authors.initials: S
authors.lastname: Morzenti
authors.forename: Marco
authors.initials: M
authors.lastname: Menzaghi
authors.forename: Riccardo
authors.initials: R
authors.lastname: Campini
authors.forename: Claudio
authors.initials: C
authors.lastname: Marcassa
authors.forename: Angelo
authors.initials: A
authors.lastname: Del Sole
authors.forename: Silvana
authors.initials: S
authors.lastname: Garancini
authors.forename: Cinzia
authors.initials: C
authors.lastname: Crivellaro
authors.forename: Marco
authors.initials: M
authors.lastname: Brambilla
authors.forename: Michela
authors.initials: M
authors.lastname: Lecchi
mesh_terms: D000465:Algorithms; D000886:Anthropometry; D015902:Gamma Cameras; D006321:Heart / Q000000981:diagnostic imaging; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D015233:Models, Statistical; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D012542:Scattering, Radiation; D012984:Software; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*