title: Micro-CT evaluation of rheumatoid arthritis mouse model disease progression: Manual tracings versus semi-automated routines.
abstract: OBJECTIVE
  The primary goal of this study was to demonstrate the value of micro-CT imaging in a rheumatoid arthritis (RA) mouse model. The secondary goal was to assess whether manual correction of the articular surface regions of interest (ROI) identification of the semi-automated methods may result in more effective assessment of bone volume and density loss.
  
  
  METHODS
  Collagen-induced arthritis (CIA) was induced in six DBA/1J mice at 12 weeks of age and three other DBA/1J identical mice served as controls. Micro-CT images were acquired at baseline and at four, seven, and nine weeks post-induction. Disease was monitored via ROI analysis, and ROIs were first generated using semi-automated techniques. These ROIs were manually manipulated so that a variety of edge irregularities were corrected. Effort was focused on the proximal and distal humerus and the distal femur. ROI volume and density were calculated, and data were compared. A histologic analysis of the study mice was also performed after the last time frame.
  
  
  RESULTS
  There was a significant difference between the volume data comparison between the manually manipulated data and the semi-automated routine data across all time frames and across both humeri and femurs. There was no significant difference in densities calculated in Hounsfield units across any of the time frames, humeri or femurs, except for one time frame.
  
  
  CONCLUSIONS
  Our findings suggest that the manual correction technique of semi-automated data can be used to quantify and evaluate bone volume, density, and joint surface architecture changes in a RA mouse model.
authors.affiliation: Department of Surgery, Louisiana State University Health Shreveport, 1501 Kings Highway, Shreveport, 71130 Louisiana, USA. Electronic address: aantil@lsuhsc.edu.
authors.forename: A C
authors.initials: AC
authors.lastname: Antill
authors.affiliation: Department of Surgery, Louisiana State University Health Shreveport, 1501 Kings Highway, Shreveport, 71130 Louisiana, USA. Electronic address: davidballardmd@gmail.com.
authors.forename: D H
authors.initials: DH
authors.lastname: Ballard
authors.affiliation: Department of Radiology, Louisiana State University Health Shreveport, 1501 Kings Highway, Shreveport, 71130 Louisiana, USA; Department of Orthopaedic Surgery, Louisiana State University Health Shreveport, 1501 Kings Highway, Shreveport, 71130 Louisiana, USA. Electronic address: annahans@mac.com.
authors.forename: A M
authors.initials: AM
authors.lastname: Hollister
authors.affiliation: San Antonio Military Medical Center, 3551 Roger Brooke Dr, 78234 Fort Sam Houston, USA. Electronic address: emily.j.rogers120@gmail.com.
authors.forename: E J
authors.initials: EJ
authors.lastname: Rogers
authors.affiliation: Department of Cellular Biology, Louisiana State University Health Shreveport, 1501 Kings Highway, Shreveport, 71130 Louisiana, USA. Electronic address: syang1@lsuhsc.edu.
authors.forename: S
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Radiology, Louisiana State University Health Shreveport, 1501 Kings Highway, Shreveport, 71130 Louisiana, USA; Center for Molecular Imaging and Therapy, Biomedical Research Foundation of Northwest Louisiana, 1505 Kings Hwy, 71103 Shreveport, USA. Electronic address: slokitz@biomed.org.
authors.forename: S J
authors.initials: SJ
authors.lastname: Lokitz
mesh_terms: D000818:Animals; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging*; D015519:Bone Density; D004195:Disease Models, Animal; D018450:Disease Progression; D005269:Femur / Q000000981:diagnostic imaging*; D006811:Humerus / Q000000981:diagnostic imaging*; D008811:Mice, Inbred DBA; D055114:X-Ray Microtomography
keywords: Collagen induced arthritis; Computed tomography; Disease index; Micro-CT; Rheumatoid arthritis