title: Pulmonary enhancement imaging with dual energy CT for the detection of pulmonary embolism in a rabbit model: comparison to perfusion planar scintigraphy, SPECT and SPECT-CT modalities.
abstract: OBJECTIVE
  Pulmonary enhancement imaging (PEI) derived from dual-energy computed tomographic (CT) imaging has been used to detect perfusion defects from pulmonary embolism (PE). The purpose of this study was to compare the ability of PEI, planar, single photon-emission CT (SPECT) perfusion scintigraphy, and SPECT-CT fusion images to detect perfusion defect in a PE rabbit model.
  
  
  METHODS
  A PE model was made by injecting Gelfoam into the femoral veins of rabbits (n = 16). After 2 hours, 16 experimental rabbits and three control rabbits underwent contrast-enhanced dual-energy CT scans, from which PEI and CT pulmonary angiography were created, and planar, SPECT, and SPECT-CT fusion images were then obtained and evaluated. Pathologic determination of locations and numbers of lung lobes with PE were recorded. The sensitivity and specificity of the above-mentioned modalities were calculated using the histopathologic results as reference standards.
  
  
  RESULTS
  Emboli were present in 31 pulmonary lobes and absent in 64 lung lobes in histopathologic analysis. With the histopathologic findings as the gold standard, sensitivities and specificities of PEI, planar, SPECT, and SPECT-CT fusion images to detect PE were 100% and 96.9%, 71.0% and 84.4%, 77.4% and 90.6%, and 74.2% and 93.8%, respectively. McNemar's tests showed that PEI had higher diagnostic accuracy for the detection of PE than three scintigraphic images (all P values < .05), while three scintigraphic images had similar diagnostic accuracy (all P values = NS).
  
  
  CONCLUSIONS
  This study demonstrates that PEI from dual-energy CT imaging can provide higher diagnostic accuracy for detecting PE than planar, SPECT, and SPECT-CT fusion images in a rabbit model.
authors.affiliation: Department of Nuclear Medicine, Jinling Hospital, Clinical School of Medical College, Nanjing University, Jiangsu Province, China.
authors.forename: Gui-Fen
authors.initials: GF
authors.lastname: Yang
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Yang
authors.forename: Long-Jiang
authors.initials: LJ
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Zhu
authors.forename: Xue
authors.initials: X
authors.lastname: Chai
authors.forename: Xiao-Bo
authors.initials: XB
authors.lastname: Hu
authors.forename: Yu-Xiao
authors.initials: YX
authors.lastname: Hu
authors.forename: Guang-Ming
authors.initials: GM
authors.lastname: Lu
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D007089:Image Enhancement; D055420:Perfusion Imaging; D011655:Pulmonary Embolism / Q000175:diagnosis*; D011817:Rabbits; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon