Synchrotron Radiation µCT : A Reference Tool for the Characterization of Bone Samples

International audienceTomographic techniques are attractive for the analysis of bone micro-architecture since they are non-destructive and may provide images of bone samples in three dimensions. Currently, two modalities are available: x-ray µCT (Micro-Computerized Tomography) and MRI (Magnetic Resonance Imaging). Due to the typical dimensions of trabeculae, specific µCT or MRI devices had to be developed.1,2Whereas both types of devices may deliver 3D images of bone architecture, the characteristics of these images differ 3D images of bone architecture, the characteristics of these images differ meaningfully. First, the parameter that is imaged is related to the corresponding phenomenon, either the x-rays absorption coefficient in /lCT, or the protons’ magnetization in MRI. Second, the two modalities do not offer the same spatial resolution and image quality. For in vivo imaging, an inslice spatial resolution around 100-150µlm. with a generally larger slice thickness, is typically achievable with both modalities.3, 4However, the use of x-ray µlCT is restricted to peripheral sites, such as the forearm, and this typical spatial resolution might not be significantly improved considering the problem of dose delivery. For in vitro imaging, much higher spatial resolutions are attainable at this time. In µlMRI (Micro-MRI), images of bone samples with isotropic spatial resolution of 50 µlm have been reported.5In x-ray µlCT, images with voxel sizes up to 28 µlm are available.6, 7Furthermore, the use of x-rays generated from synchrotron sources permits a spatial resolution of 1µlm