title: Local validation of the use of Evolution for Bone for bone SPECT imaging.
abstract: OBJECTIVE
  In order to locally validate the technique, a retrospective review of a cohort of randomly selected single-photon emission computed tomography (SPECT) bone scans reconstructed with ordered subsets expectation maximization (OSEM) and Evolution for Bone was undertaken.
  
  
  METHODS
  Thirty consecutive bone SPECT patient data sets (17 spine, nine pelvis, and four spine and pelvis) were chosen. Poisson resampling was used to simulate reduced count data at 50, 75, and 100% of the original number of counts. Evolution for Bone applied resolution recovery to the reduced count images. All images were compared with the original OSEM images, currently used as the standard for clinical use. A qualitative blinded assessment was made by two independent observers, who assessed for noise, contrast, and resolution.
  
  
  RESULTS
  Both radiologists saw an improvement in resolution (P = 0.776), noise (P = 0.007), and image quality with all data sets, compared with images processed purely with OSEM and viewed in Volumetrix. However, they completely disagreed on contrast, as the two radiologists scored contrast differently; however, the results are understandable.
  
  
  CONCLUSIONS
  Images with 50, 75, and 100% of the original counts viewed using Evolution for Bone have improved image quality compared with images processed purely with OSEM and viewed in Volumetrix. Evolution for Bone therefore has great potential in departments for reducing either patient doses, waiting lists, or both.
authors.affiliation: aDepartment of Medical Physics, The Royal Infirmary of Edinburgh, Edinburgh bDepartment of Medical Physics cDepartment of Radiology, Royal United Hospitals Bath NHS Foundation Trust dDepartment for Health, University of Bath, Bath, UK.
authors.forename: Ceri E
authors.initials: CE
authors.lastname: Ashton
authors.forename: Susan C
authors.initials: SC
authors.lastname: Doyle
authors.forename: Stewart
authors.initials: S
authors.lastname: Redman
authors.forename: Richard
authors.initials: R
authors.lastname: Graham
authors.forename: Gordon J
authors.initials: GJ
authors.lastname: Taylor
authors.forename: Martyn J
authors.initials: MJ
authors.lastname: Evans
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D013131:Spine / Q000000981:diagnostic imaging*; D015899:Tomography, Emission-Computed, Single-Photon