title: Reproducibility of tumor volume measurement at microCT colonography in living mice.
abstract: OBJECTIVE
  We sought to demonstrate the viability of microcomputed tomographic colonography (muCTC) as a tool for monitoring tumorigenesis in mouse models of human colorectal cancer during prospective longitudinal studies. The precision and accuracy of volumetric measurements were determined to assess whether changes in tumor volume over time were readily detectable.
  
  
  METHODS
  All animal studies were conducted under the guidelines set forth by the Institutional Animal Care and Use Committee of the American Association for Assessment and Accreditation of Laboratory Animal Care. muCTC was performed on C57BL/6J (B6) mice carrying the Min allele of Apc, ultimately yielding 18 scans. Assessments of scan quality and tumor volume were both performed once per week over 8 weeks.
  
  
  RESULTS
  Scans with a good quality rating had a mean standard deviation in tumor volume measurement of 8%. By contrast, scans with a poor quality rating had a mean standard deviation in tumor volume measurement of 35%. Variables affecting muCTC scan quality in living mice included bowel preparation, motion artifact, and tumor morphology. Tumor volume measurements were highly correlated with tumor weight (r2 = 0.87).
  
  
  CONCLUSIONS
  The reproducibility of tumor volume measurement at muCTC in living mice makes prospective longitudinal evaluation of colonic tumor response feasible. For muCTC scans of good quality, a 16% change in tumor volume can be detected at the 95% confidence level.
authors.affiliation: Department of Medical Physics, 1400 University Avenue, University of Wisconsin, Madison, WI 53706, USA.
authors.forename: Benjamin Y
authors.initials: BY
authors.lastname: Durkee
authors.forename: Sarah R
authors.initials: SR
authors.lastname: Mudd
authors.forename: Calista N
authors.initials: CN
authors.lastname: Roen
authors.forename: Linda
authors.initials: L
authors.lastname: Clipson
authors.forename: Michael A
authors.initials: MA
authors.lastname: Newton
authors.forename: Jamey P
authors.initials: JP
authors.lastname: Weichert
authors.forename: Perry J
authors.initials: PJ
authors.lastname: Pickhardt
authors.forename: Richard B
authors.initials: RB
authors.lastname: Halberg
mesh_terms: D000465:Algorithms; D000483:Alleles; D000818:Animals; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging* / Q000235:genetics / Q000473:pathology; D023881:Colonography, Computed Tomographic / Q000379:methods* / Q000706:statistics & numerical data; D004195:Disease Models, Animal; D017491:Genes, APC; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007327:Insufflation / Q000379:methods; D008137:Longitudinal Studies; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D011446:Prospective Studies; D011856:Radiographic Image Enhancement / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies