title: Functional dynamic contrast-enhanced magnetic resonance imaging in an animal model of brain metastases: a pilot study.
abstract: BACKGROUND
  Brain metastasis is a common disease with a poor prognosis. The purpose of this study is to test feasibility and safety of the animal models for brain metastases and to use dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to enhance detection of brain metastases.
  
  
  METHODS
  With approval from the institutional animal ethics committee, 18 New Zealand rabbits were randomly divided into three groups: Group A received an intra-carotid infusion (ICI) of mannitol followed by VX2 cells; group B received successive ICI of mannitol and heparin followed by VX2 cells; and group C received an ICI of normal saline. The survival rate and clinical symptoms were recorded after inoculation. After two weeks, conventional MRI and DCE-MRI were performed using 3.0 Tesla scanner. The number of tumors and detection rate were analyzed. After MRI measurements, the tumors were stained with hematoxylin-eosin.
  
  
  RESULTS
  No rabbits died during the procedure. The rabbits had common symptoms, including loss of appetite, lassitude and lethargy, etc. at 10.8±1.8 days and 8.4±1.5 days post-inoculation in group A and B, respectively. Each animal in groups A and B re-gained the lost weight within 14 days. Brain metastases could be detected by MRI at 14 days post-inoculation in both groups A and B, with metastases manifesting as nodules in the brain parenchyma and thickening in the meninges. DCE-MRI increased the total detection of tumors compared to non-contrast MRI (P<0.05). The detection rates of T1-weighted image, T2-weighted image and DCE-MRI were 12%, 32% and 100%, respectively (P<0.05). Necropsy revealed nodules or thickening meninges in the gross samples and VX2 tumor cytomorphologic features in the slides, which were consistent with the MRI results.
  
  
  CONCLUSIONS
  The VX2 rabbit model of brain metastases is feasible, as verified by MRI and pathologic findings, and may be a suitable platform for future studies of brain metastases. Functional DCE-MRI can be used to evaluate brain metastases in a rabbit model.
authors.affiliation: Department of Radiology, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Linfeng
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Department of Radiology, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai, China; Department of Radiology, Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong, China.
authors.forename: Pengpeng
authors.initials: P
authors.lastname: Sun
authors.affiliation: Dengfeng People's Hospital, Zhengzhou, Henan, China.
authors.forename: Sujuan
authors.initials: S
authors.lastname: Zheng
authors.affiliation: Department of Radiology, General Hospital of Lanzhou Military Region, Lanzhou, Gansu, China.
authors.forename: Yuedong
authors.initials: Y
authors.lastname: Han
authors.affiliation: Department of Radiology, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Guixiang
authors.initials: G
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000473:pathology* / Q000556:secondary; D045744:Cell Line, Tumor; D003287:Contrast Media; D004195:Disease Models, Animal; D008279:Magnetic Resonance Imaging / Q000009:adverse effects / Q000379:methods*; D009368:Neoplasm Transplantation; D010865:Pilot Projects; D011817:Rabbits; D011897:Random Allocation
chemical_list: D003287:Contrast Media