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Updated: May 31, 2026
Trabecular Bone Microarchitecture Evaluation in an Osteoporosis Mouse Model
Published on: September 8, 2023
Development of micro-CT protocols for in vivo follow-up of mouse bone architecture without major radiation side
K Laperre1, M Depypere, N van Gastel
1Laboratory of Experimental Medicine and Endocrinology, K.U.Leuven, Leuven, Belgium.
Abstract:
In vivo micro-computed tomography (micro-CT) will offer unique information on the time-related changes in bone mass and structure of living mice, provided that radiation-induced side effects are prevented. Lowering the radiation dose, however, inevitably decreases the image quality. In this study we developed and validated a protocol for in vivo micro-CT imaging of mouse bone architecture that retains high quality images but avoids radiation-induced side effects on bone structure and hematological parameters. The left hindlimb of male C57Bl/6 mice was scanned in vivo at 3 consecutive time points, separated each time by a 2-week interval. Two protocols for in vivo micro-CT imaging were evaluated, with pixel sizes of 9 and 18 μm and administered radiation doses of 434 mGy and 166 mGy per scan, respectively. These radiation doses were found not to influence trabecular or cortical bone architecture in pre-pubertal or adult mice. In addition, there was no evidence for hematological side effects as peripheral blood cell counts and the colony-forming capacity of hematopoietic progenitor cells from bone marrow and spleen were not altered. Although the images obtained with these in vivo micro-CT protocols were more blurred than those obtained with high resolution (5 μm) ex vivo CT imaging, longitudinal follow-up of trabecular bone architecture in an orchidectomy model proved to be feasible using the 9 μm pixel size protocol in combination with a suitable bone segmentation technique (i.e. local thresholding). The image quality of the 18 μm pixel size protocol was too degraded for accurate bone segmentation and the use of this protocol is therefore restricted to monitor marked changes in bone structure such as bone metastatic lesions or fracture healing. In conclusion, we developed two micro-CT protocols which are appropriate for detailed as well as global longitudinal studies of mouse bone architecture and lack noticeable radiation-induced side effects.
Insights
We developed safe in vivo micro-CT protocols for studying mouse bone structure over time. These methods provide high-quality images without causing radiation damage to bone or blood, enabling detailed longitudinal analysis.
Area of Science:
- * Biomedical imaging
- * Bone research
- * Mouse models
Background:
- * In vivo micro-computed tomography (micro-CT) offers insights into dynamic bone changes in living mice.
- * Balancing image quality and radiation dose is crucial to prevent side effects.
- * Previous methods faced limitations in image resolution versus radiation exposure.
Purpose of the Study:
- * To develop and validate in vivo micro-CT protocols for mouse bone architecture analysis.
- * To ensure protocols minimize radiation-induced side effects on bone and hematological parameters.
- * To assess the feasibility of longitudinal bone studies with optimized imaging parameters.
Main Methods:
- * Two in vivo micro-CT protocols (9 μm and 18 μm pixel size) were evaluated on male C57Bl/6 mice.
- * Scans were performed at three time points with 2-week intervals.
- * Radiation doses were 434 mGy (9 μm) and 166 mGy (18 μm) per scan.
- * Bone architecture, peripheral blood cell counts, and hematopoietic progenitor cell capacity were assessed.
Main Results:
- * Both 434 mGy and 166 mGy radiation doses did not affect trabecular or cortical bone architecture.
- * No hematological side effects were observed in peripheral blood or bone marrow.
- * The 9 μm protocol with local thresholding enabled longitudinal tracking of bone architecture in an orchidectomy model.
- * The 18 μm protocol's image quality was insufficient for detailed segmentation but suitable for monitoring major changes.
Conclusions:
- * Two validated in vivo micro-CT protocols are suitable for longitudinal mouse bone studies.
- * These protocols effectively prevent radiation-induced side effects on bone structure and hematology.
- * The 9 μm protocol supports detailed analysis, while the 18 μm protocol is useful for global monitoring.
