title: Micro-CT imaging with a hepatocyte-selective contrast agent for detecting liver metastasis in living mice.
abstract: OBJECTIVE
  Micro-computed tomography (CT) is a important tool for longitudinal imaging of tumor development. The detection and monitoring of tumors in the liver in live animals using micro-CT is challenging. We evaluated the feasibility of high-resolution micro-CT enhanced with a hepatocyte-selective contrast agent for detecting liver metastases in a live murine model.
  
  
  METHODS
  Hepatic metastases were induced in 10 BALB/C mice. Two mice each were randomly selected on days 3, 5, 7, 10, and 13 after CT26 colon adenocarcinoma cells were injected into the portal vein; micro-CT imaging was performed at 10 minutes and 4 hours after intravenous administration of a hepatocyte-selective contrast agent at a dose of 0.4 mL/mouse. The attenuation values of the normal liver and the tumors were obtained. The number of metastases was counted and their sizes were measured on the micro-CT images. Gross or histopathologic evaluation was performed for correlating the liver tumors with the micro-CT images.
  
  
  RESULTS
  A total of 74 separate tumor sites larger than 300 microm in diameter were detected on pathologic examination of the mice that were sacrificed 7 days after cell injection. On micro-CT, 66 of 74 tumors were detected (83.8%). The smallest tumor detected on micro-CT was 300 microm. There were eight false-negative readings on micro-CT. The sizes of the individual liver metastases measured by micro-CT and on the excised specimen were highly correlated (P < .001). The correlation between the CT scan measurement and the actual measurement was r = 0.8354 (P < .0001).
  
  
  CONCLUSIONS
  High-resolution micro-CT enhanced with a hepatocyte-selective contrast agent can be a promising tool for detecting liver metastases in a live murine model.
authors.affiliation: Department of Radiology and the Institute for Radiological Imaging Science, Wonkwang University School of Medicine, 344-2 Sinyong-dong, Iksan, Jeonbuk 570-749, Korea.
authors.forename: Hye Won
authors.initials: HW
authors.lastname: Kim
authors.forename: Quan-Yu
authors.initials: QY
authors.lastname: Cai
authors.forename: Hong Yeoung
authors.initials: HY
authors.lastname: Jun
authors.forename: Kwon Su
authors.initials: KS
authors.lastname: Chon
authors.forename: Seung Hoon
authors.initials: SH
authors.lastname: Park
authors.forename: Seung Jae
authors.initials: SJ
authors.lastname: Byun
authors.forename: Myung Soo
authors.initials: MS
authors.lastname: Lee
authors.forename: Jae Min
authors.initials: JM
authors.lastname: Oh
authors.forename: Hun Soo
authors.initials: HS
authors.lastname: Kim
authors.forename: Kwon-Ha
authors.initials: KH
authors.lastname: Yoon
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000556:secondary*; D000818:Animals; D045744:Cell Line, Tumor; D003287:Contrast Media; D022781:Hepatocytes / Q000000981:diagnostic imaging*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D051379:Mice; D008807:Mice, Inbred BALB C; D011856:Radiographic Image Enhancement / Q000379:methods
chemical_list: D003287:Contrast Media