title: Low contrast medium and radiation dose for hepatic computed tomography perfusion of rabbit VX2 tumor.
abstract: OBJECTIVE
  To evaluate the feasibility of low contrast medium and radiation dose for hepatic computed tomography (CT) perfusion of rabbit VX2 tumor.
  
  
  METHODS
  Eleven rabbits with hepatic VX2 tumor underwent perfusion CT scanning with a 24-h interval between a conventional tube potential (120 kVp) protocol with 350 mgI/mL contrast medium and filtered back projection, and a low tube potential (80 kVp) protocol with 270 mgI/mL contrast medium with iterative reconstruction. Correlation and agreement among perfusion parameters acquired by the conventional and low dose protocols were assessed for the viable tumor component as well as whole tumor. Image noise and tumor-to-liver contrast to noise ratio during arterial and portal venous phases were evaluated.
  
  
  RESULTS
  A 38% reduction in contrast medium dose (360.1 ± 13.3 mgI/kg vs 583.5 ± 21.5 mgI/kg, P < 0.001) and a 73% decrease in radiation dose (1898.5 mGy • cm vs 6951.8 mGy • cm) were observed. Interestingly, there was a strong positive correlation in hepatic arterial perfusion (r = 0.907, P < 0.001; r = 0.879, P < 0.001), hepatic portal perfusion (r = 0.819, P = 0.002; r = 0.831, P = 0.002), and hepatic blood flow (r = 0.945, P < 0.001; r = 0.930, P < 0.001) as well as a moderate correlation in hepatic perfusion index (r = 0.736, P = 0.01; r = 0.636, P = 0.035) between the low dose protocol with iterative reconstruction and the conventional protocol for the viable tumor component and the whole tumor. These two imaging protocols provided a moderate but acceptable agreement for perfusion parameters and similar tumor-to-liver CNR during arterial and portal venous phases (5.63 ± 2.38 vs 6.16 ± 2.60, P = 0.814; 4.60 ± 1.27 vs 5.11 ± 1.74, P = 0.587).
  
  
  CONCLUSIONS
  Compared with the conventional protocol, low contrast medium and radiation dose with iterative reconstruction has no significant influence on hepatic perfusion parameters for rabbits VX2 tumor.
authors.affiliation: Cai-Yuan Zhang, Yan-Fen Cui, Chen Guo, Jing Cai, Ya-Fang Weng, Li-Jun Wang, Deng-Bin Wang, Department of Radiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China.
authors.forename: Cai-Yuan
authors.initials: CY
authors.lastname: Zhang
authors.affiliation: Cai-Yuan Zhang, Yan-Fen Cui, Chen Guo, Jing Cai, Ya-Fang Weng, Li-Jun Wang, Deng-Bin Wang, Department of Radiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China.
authors.forename: Yan-Fen
authors.initials: YF
authors.lastname: Cui
authors.affiliation: Cai-Yuan Zhang, Yan-Fen Cui, Chen Guo, Jing Cai, Ya-Fang Weng, Li-Jun Wang, Deng-Bin Wang, Department of Radiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Guo
authors.affiliation: Cai-Yuan Zhang, Yan-Fen Cui, Chen Guo, Jing Cai, Ya-Fang Weng, Li-Jun Wang, Deng-Bin Wang, Department of Radiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Cai
authors.affiliation: Cai-Yuan Zhang, Yan-Fen Cui, Chen Guo, Jing Cai, Ya-Fang Weng, Li-Jun Wang, Deng-Bin Wang, Department of Radiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China.
authors.forename: Ya-Fang
authors.initials: YF
authors.lastname: Weng
authors.affiliation: Cai-Yuan Zhang, Yan-Fen Cui, Chen Guo, Jing Cai, Ya-Fang Weng, Li-Jun Wang, Deng-Bin Wang, Department of Radiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China.
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Wang
authors.affiliation: Cai-Yuan Zhang, Yan-Fen Cui, Chen Guo, Jing Cai, Ya-Fang Weng, Li-Jun Wang, Deng-Bin Wang, Department of Radiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China.
authors.forename: Deng-Bin
authors.initials: DB
authors.lastname: Wang
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D003287:Contrast Media / Q000008:administration & dosage*; D005240:Feasibility Studies; D007472:Iohexol / Q000008:administration & dosage*; D008114:Liver Neoplasms, Experimental / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000473:pathology; D055806:Microvessels / Q000000981:diagnostic imaging / Q000503:physiopathology; D061330:Multidetector Computed Tomography; D055420:Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011817:Rabbits; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D012039:Regional Blood Flow
chemical_list: D003287:Contrast Media; D007472:Iohexol
keywords: Liver; Low concentration contrast medium; Low radiation dose; Perfusion computed tomography; VX2 tumor