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

Area of Science:

• Biomedical Engineering
• Materials Science
• Orthopedics

Background:

• Microcomputed tomography (microCT) is crucial for 3D bone analysis.
• Reproducibility and agreement of microCT measurements across systems, especially at high resolutions, are not well-established.

Purpose of the Study:

• To compare the performance reproducibility of three ex vivo microCT systems.
• To evaluate morphometric measurements of mouse cancellous bone at different voxel sizes.

Main Methods:

• 3D morphometric analyses of mouse distal femoral epiphyses were performed using GE eXplore Locus SP, Scanco μCT35, and Skyscan 1172 microCT systems.
• Scans were conducted in triplicate at 12 μm and 8 μm voxel sizes.
• Trabecular bone morphometry parameters were analyzed, examining relative values, voxel size dependence, and intra-system reproducibility.

Main Results:

• Bone volume fraction and trabecular separation showed agreement across systems.
• Relative bone surface, trabecular thickness, and number varied significantly among the three microCT systems.
• Trabecular thickness and number showed the largest discrepancies (up to 236% and 218%, respectively).
• Voxel size dependence varied, particularly for trabecular number (0-20% difference).
• Intra-system reproducibility was variable and generally improved with smaller voxel sizes for some parameters and systems.

Conclusions:

• Direct comparison of trabecular morphometry measurements obtained from different microCT systems is not advisable.
• Optimal microCT system and voxel size selection for mouse bone studies should be based on specific measurement interests and the system used.