title: Combining dynamic contrast enhanced magnetic resonance imaging and microvessel density to assess the angiogenesis after PEI in a rabbit VX2 liver tumor model.
abstract: OBJECTIVE
  To evaluate the correlation between parameters of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) and microvessel density (MVD) measurements in rabbit VX2 liver tumor models after percutaneous ethanol injection (PEI) and to observe influence of PEI on angiogenesis in a rabbit VX2 liver tumor model with dynamic contrast enhanced magnetic resonance imaging (DCE-MRI).
  
  
  METHODS
  Forty five New Zealand white rabbits were used in this study. VX2 tumor tissue blocks were implanted in the left lobe of liver by percutaneous puncture under CT guidance. 2 weeks later, all rabbits underwent conventional MRI (T1WI, T2WI) to determine the successful models. Then those successful implanted VX2 liver tumor models in the study were randomly divided into the control group and the experimental group, the former did not have processing, and the latter underwent PEI under CT guidance. MRI (T1WI, T2WI and DCE-MRI) was performed 1 week later again, the parameters of DCE-MRI (Ktrans, Kep, Ve and iAUC60) of viable tumor portions were observed. Then all the liver samples were processed for hematoxylin and eosin (H&E) staining and immunohistochemical staining for CD31 to determine MVD. At last, data (including DCE-MRI perfusion parameters and MVD) were compared between experimental and control groups, correlation of DCE-MRI perfusion parameters and MVD was evaluated.
  
  
  RESULTS
  Twenty six VX2 liver tumor models underwent all examinations (thirteen models for each group) 1 week later after PEI. For the experimental group, the parameters Ktrans (r=0.6382, P=0.0189) and iAUC60 (r=0.6591, P=0.0143) in viable tumor portions were positively moderately correlated with MVD, whereas the parameters Kep (r=0.4656, P=0.1088) and Ve (r=0.2918, P=0.3333) were not correlated with MVD. For the control group, the parameters Ktrans (r=0.6385, P=0.0188) and iAUC60 (r=0.6391, P=0.0187) in viable tumor portions were also positively moderately correlated with MVD, while the parameters Kep (r=0.5518, P=0.0506) and Ve (r=-0.0824, P=0.789) were not correlated with MVD. Ktrans, Kep, Ve, iAUC60 and MVD of residual viable tumors in the experimental group 1 week later after PEI were similar to the viable tumors of the control group (P>0.05).
  
  
  CONCLUSIONS
  DCE-MRI could be used to evaluate the efficiency of VX2 liver tumor after PEI. The quantitative parameter Ktrans and semi-quantitative parameter iAUC60 of DCE-MRI are correlated with MVD, which can assess tumor angiogenesis noninvasively of VX2 liver tumor model, and ethanol has no significant impact on angiogenesis of viable tumor 1week later after PEI.
authors.affiliation: Department of Radiology, The Fifth People of Shanghai, Fudan University, Shanghai, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Radiology, The Fifth People of Shanghai, Fudan University, Shanghai, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Qian
authors.affiliation: Department of Radiology, The Fifth People of Shanghai, Fudan University, Shanghai, China.
authors.forename: Huanhuan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Radiology, The Fifth People of Shanghai, Fudan University, Shanghai, China.
authors.forename: Chunxiao
authors.initials: C
authors.lastname: Wei
authors.affiliation: Department of Radiology, The Fifth People of Shanghai, Fudan University, Shanghai, China.
authors.forename: Fanhua
authors.initials: F
authors.lastname: Meng
authors.affiliation: Department of Radiology, The Fifth People of Shanghai, Fudan University, Shanghai, China. Electronic address: hbyin1961@126.com.
authors.forename: Huabin
authors.initials: H
authors.lastname: Yin
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D003287:Contrast Media; D000431:Ethanol; D007089:Image Enhancement / Q000379:methods*; D008113:Liver Neoplasms / Q000139:chemically induced / Q000473:pathology*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D055806:Microvessels / Q000473:pathology*; D009389:Neovascularization, Pathologic / Q000139:chemically induced / Q000473:pathology*; D011817:Rabbits; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D000431:Ethanol
keywords: Magnetic resonance imaging (MRI); Microvessel density (MVD); Percutaneous ethanol injection (PEI); Perfusion imaging