title: Quantification of bone changes in a collagen-induced arthritis mouse model by reconstructed three dimensional micro-CT.
abstract: BACKGROUND
  Inflammatory arthritis is a chronic disease, resulting in synovitis and subchondral and bone area destruction, which can severely affect a patient's quality of life. The most common form of inflammatory arthritis is rheumatoid arthritis (RA) in which many of the disease mechanisms are not well understood. The collagen-induced arthritis (CIA) mouse model is similar to RA as it exhibits joint space narrowing and bone erosion as well as involves inflammatory factors and cellular players that have been implicated in RA pathogenesis. Quantitative data for disease progression in RA models is difficult to obtain as serum blood markers may not always reflect disease state and physical disease indexes are subjective. Thus, it is important to develop tools to objectively assess disease progression in CIA.
  
  
  RESULTS
  Micro-CT (Computed Tomography) is a relatively mature technology that has been used to track a variety of anatomical changes in small animals. In this study, micro-CT scans of several joints of control and CIA mice were acquired at 0, 4, 7, and 9 weeks after the immunization with collagen type II. Each micro-CT scan was analyzed by applying a segmentation algorithm to individual slices in each image set to provide 3-dimensional representations of specific bones including the humerus, femur, and tibia. From these representations, the volume and mean density of these bones were measured and compared. This analysis showed that both the volume and the density of each measured bone of the CIA mice were significantly smaller than those of the controls at week 7.
  
  
  CONCLUSIONS
  This study demonstrates that micro-CT can be used to quantify bone changes in the CIA mouse model as an alternative to disease index assessments. In conclusion, micro-CT could be useful as a non-invasive method to monitor the efficacy of new treatments for RA tested in small animals.
authors.affiliation: Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, 1501 Kings Hwy, Shreveport, LA 71130, USA.
authors.forename: Shu
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Orthopedics, Louisiana State University Health Sciences Center, 1501 Kings Hwy, Shreveport, LA 71130, USA.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Hollister
authors.affiliation: Department of Animal Resources, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA ; Department of Pharmacology, Toxicology, and Neurosciences, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA.
authors.forename: Elysse A
authors.initials: EA
authors.lastname: Orchard
authors.affiliation: Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA.
authors.forename: Shubnum I
authors.initials: SI
authors.lastname: Chaudhery
authors.affiliation: Department of Medicine, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA.
authors.forename: Dmitry V
authors.initials: DV
authors.lastname: Ostanin
authors.affiliation: Department of Radiology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA ; PET Imaging Center, Biomedical Research Foundation of Northwest Louisiana, Shreveport, LA 71130, USA.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Lokitz
authors.affiliation: Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, 1501 Kings Hwy, Shreveport, LA 71130, USA.
authors.forename: J Michael
authors.initials: JM
authors.lastname: Mathis
keywords: Bone density; Bone volume; Collagen induced arthritis; Computed tomography; Disease index; Imaging; Micro-CT; Rheumatoid arthritis