title: Could temporal window for the computed tomography hepatic venography (CTHV) be extended?: A comparative study between spectral and conventional CT using porcine models.
abstract: OBJECTIVE
  To investigate the feasibility of extending the acceptable temporal window for hepatic venography with dual-energy spectral CT imaging.
  
  
  METHODS
  Five normal pigs anesthetized intramuscularly were scanned on a multislice CT (GE Discovery HD750 CT) after bolus contrast injection. Twelve CT scans with dual-energy spectral imaging mode were performed on each pig with a 10-second interval. Both conventional polychromatic and monochromatic image sets were reconstructed. The optimal energy level for hepatic vein imaging was selected from the monochromatic image sets based on the contrast-to-noise ratio (CNR) analysis. Subjective assessment of image quality was performed on volume-rendering images at 12 imaging points in time.
  
  
  RESULTS
  The CNRs for hepatic veins in the polychromatic, default monochromatic 65 keV, and the optimal energy images were 2.24 ± 1.09, 3.48 ± 1.73, and 6.72 ± 2.56, respectively, with a significant difference among 3 groups (P < 0.001). There was no acceptable temporal window for imaging hepatic veins in the polychromatic group, but a peak plateau existed. The temporal window in the 65-keV group was 20 seconds, whereas it was 70 seconds in the optimal energy group.
  
  
  CONCLUSIONS
  Compared with conventional polychromatic CT images, monochromatic images provided superior CNR for hepatic veins and 3.5 times temporal window of hepatic venography in spectral CT.
authors.affiliation: Department of Radiology, The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Yudong
authors.initials: Y
authors.lastname: Qiu
authors.forename: Jian
authors.initials: J
authors.lastname: He
authors.forename: Zhengyang
authors.initials: Z
authors.lastname: Zhou
authors.forename: Baoxin
authors.initials: B
authors.lastname: Li
authors.forename: Bin
authors.initials: B
authors.lastname: Zhu
authors.forename: Xizhao
authors.initials: X
authors.lastname: Sun
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D005240:Feasibility Studies; D006503:Hepatic Veins / Q000000981:diagnostic imaging*; D007472:Iohexol / Q000008:administration & dosage; D023421:Models, Animal; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D013552:Swine; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol