title: Clinical value of dual-energy spectral imaging with adaptive statistical iterative reconstruction for reducing contrast medium dose in CT portal venography: in comparison with standard 120-kVp imaging protocol.
abstract: OBJECTIVE
  To evaluate the clinical value of dual-energy spectral CT with adaptive statistical iterative reconstruction (ASiR) for reducing contrast medium dose in CT portal venography (CTPV).
  
  
  METHODS
  This prospective study was institutional review board-approved, and written informed consent was obtained from all patients. 50 patients undergoing abdominal CT were randomized to 2 groups: Group A (n = 25), using spectral CT and 350 mgI kg(-1) contrast injection protocol; Group B (n = 25), using standard 120 kVp and 500 mgI kg(-1) contrast. Spectral CT images at 60 keV and standard 120-kVp images were both reconstructed with 50% ASiR. CT number and contrast-to-noise ratio (CNR) for intrahepatic and extrahepatic portal veins were measured. The maximum intensity projection (MIP) and volume-rendering (VR) images were used for subjective evaluation. These two kinds of results were statistically analyzed.
  
  
  RESULTS
  CNR values for the intrahepatic portal vein of the 60-keV spectral images (4.2 ± 1.1) were higher than those of 120-kVp images (3.0 ± 2.1) (p = 0.03) and were the same for the extrahepatic portal vein (5.9 ± 1.4 vs 5.9 ± 1.6, p = 0.90). The portal vein and left and right branches in the 60-keV spectral images had higher CT number and lower standard deviation than the 120-kVp images (p < 0.05). Radiation dose (dose-length product and effective dose) and subjective image quality were similar for the two groups, while the spectral CT group required 25% less iodine dose (23.1 ± 3.2 g vs 30.5 ± 5.0 g).
  
  
  CONCLUSIONS
  The 60-keV spectral CT images with ASiR allow 25% reduction in the iodine dose while providing better or equal image quality as the standard 120-kVp images in portal venography with comparable radiation dose.
  
  
  CONCLUSIONS
  Compared with conventional 120-kVp CT, the use of 60-keV spectral CT images provides 25% contrast dose reduction with similar image quality in CTPV. Compared with conventional 120-kVp CT, the use of 60-keV spectral CT images with ASiR algorithm improves CNR values for the intrahepatic portal vein.
authors.affiliation: Department of Radiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, People's Republic of China.
authors.forename: Chun-Ling
authors.initials: CL
authors.lastname: Ma
authors.affiliation: Department of Radiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, People's Republic of China.
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Chen
authors.affiliation: Department of Radiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, People's Republic of China.
authors.forename: Yu-Xin
authors.initials: YX
authors.lastname: Lei
authors.affiliation: Department of Radiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, People's Republic of China.
authors.forename: Xi-Rong
authors.initials: XR
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, People's Republic of China.
authors.forename: Yong-Jun
authors.initials: YJ
authors.lastname: Jia
authors.affiliation: Department of Radiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Tian
authors.affiliation: Department of Radiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, People's Republic of China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Tian
mesh_terms: D000465:Algorithms; D003287:Contrast Media; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010690:Phlebography / Q000379:methods*; D011169:Portal Vein / Q000000981:diagnostic imaging*; D000069079:Radiation Exposure / Q000032:analysis / Q000517:prevention & control*; D011835:Radiation Protection / Q000379:methods; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media