Post-euthanasia micro-computed tomography-based strain analysis is able to represent quasi-static in vivo behavior of whole vertebrae.

Three-dimensional image-based strain measurement in whole bones allows representation of physiological, albeit quasi-static, loading conditions. However, such work to date has been limited to specimens postmortem. The main purpose of this study is to verify the efficacy of deformable image registration of post-euthanasia strain to characterize the in vivo mechanical behavior of rat vertebrae. A micro-computed tomography–compatible custom loading device was used to apply 75 N load to a three-level caudal motion segment of a healthy rat. Loaded and unloaded micro-computed tomography scans were acquired in vivo and post-sacrifice. A micro-computed tomography–based deformable image registration algorithm was used to calculate vertebral strains live and post-euthanasia. No significant difference was found in the in vivo strains (−0.011 ± 0.001) and ex vivo strains (−0.012 ± 0.001) obtained from the comparisons of loaded and unloaded images (p = 0.3). Comparisons between unloaded–unloaded and loaded–loaded scan...