Simultaneous 3D Imaging of Bone and Vessel Microstructure in a Rat Model

Abstract

Analysis of bone microvascularization has generally been performed from 2D histology. The method proposed in this study enables for the first time to simultaneously analyze, in 3D, the microvascularization and bone microstructure in a rat model. The method is based on the use of quantitative synchrotron micro-computed tomography (SR-CT) coupled to an automatic image analysis procedure. It was applied to investigate the effect of intermittent parathyroid hormone (PTH) administration on angiogenesis and osteogenesis in rats. Rats were posthumously injected with a contrast agent and subsequently imaged. The algorithm allowed the reconstruction and the segmentation of both bone microstructure and microvascularization in cortical and trabecular regions. A large set of 3D quantitative parameters were then extracted from the bone and vascular networks. In particular, we propose a new parameter, utilizing the availability of both microstructures to relate the two, which we dub the vascular-trabecular interdistance (VTI). Due to the short acquisition times of SR-CT and the efficiency of the image analysis algorithm, a large data set was analyzed, which permitted statistical analysis of the measured parameters. Statistical analysis confirmed that treatment with PTH significantly modulated several bone and vessel parameters, including the VTI.

Vascular imaging with contrast agent in hard and soft tissues using microcomputed‐tomography

“…In 1987, Parfitt et al (Parfitt et al, 1987 standardized the symbols and units of the different bone microarchitecture parameters. Recently, other authors have studied vascular microarchitecture parameters, extrapolated from bone microarchitecture parameters (Bolland et al, 2008;Jia et al, 2010;Langer et al, 2011;Prisby et al, 2011;Roche et al, 2012) using radio-opaque contrast agent. To calculate the vascular microarchitecture parameters, the vascular tree should be visible almost in its entirety.…”

“…In imaging studies, a contrast agent is often used to highlight the vessels. Many contrast agents can be used: iodine, liquid fatty oil, resin, gold nanoparticles and the two most commonly used Microfil R and barium sulphate (Duvall et al, 2004;Marxen et al, 2004;Grabherr et al, 2007;Young et al, 2008;Mondy et al, 2009aMondy et al, , 2009bSchneider et al, 2009;Chien et al, 2010;Hallouard et al, 2010;Jia et al, 2010;Langer et al, 2011;Nyangoga et al, 2011;Pabst et al, 2014;Roche et al, 2012). We have made a lot of tests using these two contrast agents.…”

Parathyroid hormone for bone regeneration

“…PTH administration can also influence endothelial cells and stem cells which may aid in bone healing . The impact PTH has on vascular regeneration as well as proliferation may aid in its anabolic capabilities for bone regeneration applications.…”

Synchrotron Phase Tomography: An Emerging Imaging Method for Microvessel Detection in Engineered Bone of Craniofacial Districts

“…It was recently proved by this approach that the 10 μm medium resolution microCT is able to image with success medium and large blood vessels (Nebuloni et al, 2014 ). Moreover, Langer et al (Langer et al, 2011 ) successfully imaged the microvasculature with contrast agent in rat and mouse bone. While they proved that parts of the connectivity were not preserved (due to partial volume effect), a very large part of the contrast agent volume was retrieved.…”