Quantification of the bone lacunocanalicular network from 3D X‐ray phase nanotomography images

Abstract

Summary There is a growing interest in developing 3D microscopy for the exploration of thick biological tissues. Recently, 3D X‐ray nanocomputerised tomography has proven to be a suitable technique for imaging the bone lacunocanalicular network. This interconnected structure is hosting the osteocytes which play a major role in maintaining bone quality through remodelling processes. 3D images have the potential to reveal the architecture of cellular networks, but their quantitative analysis remains a challenge due to the density and complexity of nanometre sized structures and the need to handle and process large datasets, for example, 20483 voxels corresponding to 32 GB per individual image in our case. In this work, we propose an efficient image processing approach for the segmentation of the network and the extraction of characteristic parameters describing the 3D structure. These parameters include the density of lacunae, the porosity of lacunae and canaliculi, and morphological features of lacunae (volume, surface area, lengths, anisotropy etc.). We also introduce additional parameters describing the local environment of each lacuna and its canaliculi. The method is applied to analyse eight human femoral cortical bone samples imaged by magnified X‐ray phase nanotomography with a voxel size of 120 nm, which was found to be a good compromise to resolve canaliculi while keeping a sufficiently large field of view of 246 μm in 3D. The analysis was performed on a total of 2077 lacunae showing an average length, width and depth of 17.1 μm × 9.2 μm × 4.4 μm, with an average number of 58.2 canaliculi per lacuna and a total lacuno‐canalicular porosity of 1.12%. The reported descriptive parameters provide information on the 3D organisation of the lacuno‐canalicular network in human bones.

Simulated Increase in Monoarticular Hip Muscle Strength Reduces the First Peak of Knee Compression Forces During Walking

“…Finally, morphometric parameters, such as the canalicular and LCN (canaliculi þ lacunae) total volume fraction (Ca.V/BV and LCN.V/BV in %, respectively) where BV is the bone volume, the canalicular diameter (Ca.D in mm), and the canalicular number in function of the distance to their closest lacuna (Ca.N) were quantified. This parameter was obtained by measuring the number of holes in a surface growing from the lacunar wall to a surface 12 mm away from it (Yu 2021).…”

Osteocyte pericellular and perilacunar matrices as markers of bone–implant mechanical integrity

“…These lacunae are all connected together through canaliculi, 400 nm in diameter (Varga et al, 2014;Yu et al, 2020). It is estimated that one lacuna is connected to 58 canaliculi, on average, in human femoral diaphysis (Yu et al, 2021). Even with their micrometer and nanometer scales, both lacunae and canaliculi play a role in the tissue mechanical response (Hemmatian et al, 2021;Verbruggen et al, 2012, Figs.…”

Polychromatic neutron phase-contrast imaging of weakly absorbing samples enabled by phase retrieval

“…The benefit of the latter is that no gratings or other specialized elements are needed to measure the phase shift. Therefore, propagation-based phase-contrast imaging has evolved into a very powerful tool in X-ray imaging (Alloo et al, 2022;Bidola et al, 2017;Wieland et al, 2021;Yu et al, 2021) but has only been investigated for neutrons in a very few cases (Allman et al, 2000;Jacobson et al, 2004;Lehmann et al, 2005;McMahon et al, 2003).…”