Accuracy and reproducibility of mouse cortical bone microporosity as quantified by desktop microcomputed tomography

Abstract

Bone's microporosity plays important roles in bone biology and bone mechanical quality. In this study, we explored the accuracy and reproducibility of nondestructive desktop μCT for 3D visualization and subsequent morphometric analysis of mouse cortical bone microporosity including the vascular canal network and osteocyte lacunae. The accuracy of measurements was evaluated in five murine fibula using confocal laser scanning microscopy (CLSM) in conjunction with Fluorescein isothiocyanate (FITC) staining as the reference method. The reproducibility of μCT-derived cortical bone microstructural indices was examined in 10 fibulae of C57Bl/6J male mice at a nominal resolution of 700 nanometer. Three repeated measurements were made on different days. An excellent correlation between μCT and CLSM was observed for both mean lacuna volume (r = 0.98, p = 0.002) and for mean lacuna orientation (r = 0.93, p = 0.02). Whereas the two techniques showed no significant differences for these parameters, the mean lacuna sphericity acquired from μCT was significantly higher than CLSM (p = 0.01). Reproducibility was high, with precision errors (PE) of 1.57–4.69% for lacuna parameters, and of 1.01–9.45% for vascular canal parameters. Intraclass correlation coefficient (ICC) showed a high reliability of the measurements, ranging from 0.998–1.000 for cortical parameters, 0.973–0.999 for vascular canal parameters and 0.755–0.991 for lacuna parameters. In conclusion, desktop μCT is a valuable tool to quantify the 3D characteristics of bone vascular canals as well as lacunae which can be applied to intact murine bones with high accuracy and reproducibility. Thus, μCT might be an important tool to improve our understanding of the physiological and biomechanical significance of these cannular and lacunar structure in cortical bone.

Mechanical Loading Differentially Affects Osteocytes in Fibulae from Lactating Mice Compared to Osteocytes in Virgin Mice: Possible Role for Lacuna Size

“…We previously showed that the osteocyte lacunae are becoming smaller and more spherical with aging [ 19 , 28 ]. The findings of the present study indicate that bones with smaller lacunae respond less to mechanical loading than bones with larger lacunae, suggesting that smaller lacunae in aged bones are a potential causative factor for the reduced bone mechanoresponsiveness with aging.…”

“…Image processing and segmentation of osteocyte lacunar network were performed using our previously reported technique [ 28 ]. Briefly, a histogram-based global thresholding method was applied to the reconstructed images to segment the mineralized tissue and nonmineralized structures.…”

Comparative Analysis of Bone Structural Parameters Reveals Subchondral Cortical Plate Resorption and Increased Trabecular Bone Remodeling in Human Facet Joint Osteoarthritis

“…Binary images were further processed using ImageJ (Version 1.49v, National Institute of Health, Bethesda, MD, USA) to close pores prior to measurement of the SCP thickness (SCP.Th). The accuracy (coefficient of variation <0.5%) and reproducibility (intraclass correlation coefficient: 0.999–1.00) of volumetric assessments are very high for routine desktop μCT scanners [ 34 ].…”

An Automated Step-Wise Micro-Compression Device for 3D Dynamic Image-Guided Failure Assessment of Bone Tissue on a Microstructural Level Using Time-Lapsed Tomography

“…Nevertheless, it is important to note that although SR imaging does negatively affect the mechanical bone properties, it does not affect the microstructure itself. A recent study found high reproducibility and inter-class correlations of microstructural bone parameters (Hemmatian et al, 2017) indicating that there are no significant microstructural changes at this level of resolution even after multiple image acquisitions. Additionally, it should be mentioned that our studies used whole femurs that were notched in the mid-diaphysis of the bones.…”