MicroCT morphometry analysis of mouse cancellous bone: Intra- and inter-system reproducibility

Abstract

The agreement between measurements and the relative performance reproducibility among different microcomputed tomography (microCT) systems, especially at voxel sizes close to the limit of the instruments, is not known. To compare this reproducibility 3D morphometric analyses of mouse cancellous bone from distal femoral epiphyses were performed using three different ex vivo microCT systems: GE eXplore Locus SP, Scanco μCT35 and Skyscan 1172. Scans were completed in triplicate at 12μm and 8μm voxel sizes and morphometry measurements, from which relative values and dependence on voxel size were examined. Global and individual visually assessed thresholds were compared. Variability from repeated scans at 12μm voxel size was also examined. Bone volume fraction and trabecular separation values were similar, while values for relative bone surface, trabecular thickness and number varied significantly across the three systems. The greatest differences were measured in trabecular thickness (up to 236%) and number (up to 218%). The relative dependence of measurements on voxel size was highly variable for the trabecular number (from 0% to 20% relative difference between measurements from 12μm and 8μm voxel size scans, depending on the system). The intra-system reproducibility of all trabecular measurements was also highly variable across the systems and improved for BV/TV in all the systems when a smaller voxel size was used. It improved using a smaller voxel size in all the other parameters examined for the Scanco system, but not consistently so for the GE or the Skyscan system. Our results indicate trabecular morphometry measurements should not be directly compared across microCT systems. In addition, the conditions, including voxel size, for trabecular morphometry studies in mouse bone should be chosen based on the specific microCT system and the measurements of main interest.

Lysine-specific demethylase 1 inhibitor rescues the osteogenic ability of mesenchymal stem cells under osteoporotic conditions by modulating H3K4 methylation

“…45 Second, the growth plate comprises a clear structure that is easy to recognize and define. Third, there have previously been a relatively large number of studies that have provided results for murine femurs, and values for the accuracy and reproducibility of these measures have been assessed, 32,49,50 which ensured the comparability and reproducibility of our experiments. Radiological analyses and histological staining demonstrated that aged male mice and OVX female mice exhibited a decreased BMD, a lower BV/TV, fewer and thinner trabeculae, and increased trabecular spacing, which indicates that the models of aged osteoporosis and OVX osteoporosis were successfully established.…”

Testosterone Delivered with a Scaffold Is as Effective as Bone Morphologic Protein-2 in Promoting the Repair of Critical-Size Segmental Defect of Femoral Bone in Mice

“…The right femur without scaffold was similarly examined to serve as control. Micro-CT was performed using a Skyscan 1076 instrument (Skyscan) [32]. Each femur was scanned for 260 slices each above and below the midpoint of the scaffold for a total of 8.2 mm in length.…”

A review of mouse critical size defect models in weight bearing bones

“…Briefly, a study should report a minimal set of image acquisition parameters (voxel size, X-ray tube potential, and integration times); a minimal description of trabecular bone (bone volume fraction, trabecular number, trabecular thickness, and trabecular separation); and a minimal description of cortical bone (total cross-sectional area, cortical bone area, cortical area fraction, and average cortical thickness). Reporting these parameters is essential, as different µCT machines do not give comparable results [43]. It is easy to see why the use of µCT is becoming commonplace in evaluating CSD models, and this modality will continue to evolve.…”