Simultaneous visualization of micro-damage in cortical bone, trabecular bone, and intracortical vasculature for diagnosing osteoporosis: An animal model synchrotron imaging

Osteoporosis (OP) is difficult to diagnose through the three-dimensional visualization of micro-damage. In this study, aimed to make an objective diagnosis by visualizing micro-damage caused by OP using synchrotron radiation-based mu CT (SR-mu CT). Female mice (n = 12) were randomly divided into an ovariectomized group (OVX, n = 6) in which both ovaries were excised and OP occurred, and a sham-operated group (SHAM, n = 6). After six weeks, all femurs (left and right) were excised from both groups (n = 12 per group). Thereafter, femurs were randomly divided into SR-mu CT (OVX group, n = 6; SHAM group, n = 6) and mu CT (OVX group, n = 6; SHAM group, n = 6) groups. In the SR-mu CT group, micro-damage was visualized by manually segmenting the cortical bone, trabecular bone, and intracortical vasculature using a water-shedding algorithm. In addition, trabecular bone was obtained by automatic segmentation using mu CT. Cortical bone volume/total volume was greater (p = .015), and cortical thickness was greater in the SHAM group than in the OVX group (p = .007). Among the trabecular bone parameters, the bone volume/total volume (TV) in OVX was significantly lower than that in the SHAM group (p = .012). The canal volume was greater (p = .021) and lacuna volume was greater (p < .001) in the SHAM group than in the OVX group. We expect that it will be possible to analyze damage and recovery mechanisms in the field of rehabilitation. SR-mu CT has been proposed as an objective method for OP diagnosis as it allows the visualization of microstructures.

Automated summary

This study aimed to objectively diagnose osteoporosis (OP) by visualizing micro-damage caused by OP using synchrotron radiation-based mu CT (SR-mu CT). The results showed that the OVX group had smaller cortical bone volume and thickness, as well as lower trabecular bone volume/total volume compared to the SHAM group. In addition, the SHAM group had larger canal volume and lacuna volume than the OVX group.