Following the white rabbit: multiscale 2D3D correlative imaging of bone structure

Area of Science:

• Bone biology and biomechanics
• Multiscale imaging and materials science

Background:

• Bone research faces challenges bridging different scales due to its complex structure.
• Extrapolating human bone findings to animal models like rabbits is difficult.
• Rabbit bone, a common model, is underexplored at small scales.

Purpose of the Study:

• To investigate the hierarchical structure and porosity of rabbit bone across multiple scales.
• To highlight site-specific variations in bone structure.
• To demonstrate the utility of multimodal imaging workflows.

Main Methods:

• Combined 3D micro-computed X-ray tomography (15 µm and 2 µm voxel sizes) with 2D scanning electron microscopy (<0.5 µm pixel size) and transmission electron microscopy (<50 nm pixel size).
• Integrated 2D images into 3D data using image registration for spatial context.
• Analyzed endosteal, mid-cortex, and periosteal bone regions.

Main Results:

• Identified variations in osteocyte lacunae morphology across different bone regions (endosteal, mid-cortex, periosteal) and osteon types.
• Demonstrated site-specific structural differences within rabbit bone.
• Showcased how multimodal imaging provides broader spatial context for nanoscale findings.

Conclusions:

• Osteocyte lacunae morphology differs between primary osteons, secondary osteons, and periosteal bone in rabbits.
• Further 3D characterization of osteocyte lacunar morphology is needed to understand their role in bone remodeling.
• Sequential multimodal imaging workflows enhance understanding of bone structure across scales.