title: Planar images reprojected from SPECT V/Q data perform similarly to traditional planar V/Q scans in the diagnosis of pulmonary embolism.
abstract: OBJECTIVE
  To compare the diagnostic interpretation of traditional ventilation/perfusion (V/Q) planar images with that of planar-like images reprojected from single-photon emission computed tomography (SPECT) data sets.
  
  
  METHODS
  Retrospective data from patients who had undergone both planar and SPECT imaging were used to generate anonymized reprojected planar images, which were compared with traditional planar V/Q images. Two consultants interpreted both sets of images for 81 patients following a proforma. We assessed the agreement in the final diagnosis between the two imaging methods and between the two clinicians. We also compared the number, nature, and localization of defects, as well as image quality. Finally, we compared the diagnosis made using planar methods with the original diagnosis made using SPECT.
  
  
  RESULTS
  There was excellent agreement in diagnosis both between the two planar methods (κ=0.93) and between the two consultants (κ=0.91). Similar numbers of defects were detected, with fewer matched defects being reported in the reprojected group by one of the clinicians. Localization of defects and image quality were similar for the two imaging methods. Six additional pulmonary embolisms were diagnosed using SPECT data.
  
  
  CONCLUSIONS
  We have shown that the performance of reprojected planars from SPECT V/Q was similar to that of traditional planars. These results have potential important implications for patient workflow in busy nuclear medicine departments, as well as for patient comfort.
authors: Department of Nuclear Medicine, Royal Free London NHS Foundation Trust, London, UK.
authors: Panagiotis G
authors: PG
authors: Kyrtatos
authors: Shaunak
authors: S
authors: Navalkissoor
authors: Maria
authors: M
authors: Burniston
authors: Thomas
authors: T
authors: Wagner
mesh_terms: D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007726:Krypton / Q000494:pharmacology; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D012189:Retrospective Studies; D012984:Software; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014692:Ventilation-Perfusion Ratio / Q000187:drug effects
chemical_list: D007726:Krypton