(F. Peyrin)
Purpose and context
Although new imaging techniques are developed, bone micro-architecture is still difficult to evaluate in vivo. X-ray radiography is a low cost and minimally invasive technique which is potentially attractive for screening osteoporotic patients. The goal of this study was to evaluate the relevance of bone texture analysis for the investigation of bone micro-architecture.
Methods
This work was performed in the context of the RNTS “MODATOS” (Modeling bone texture) project in partnership with the CEA-LETI, Grenoble, the CHUs of Nîmes (P.O. Kotzki) and Lille (X. Marchandise), and the company DMS. The ultimate aim of the project was to study the possibility of evaluating bone texture from new biphotonic flat panel densitometry systems developed by the LETI and DMS. The question was to determine whether or not the texture parameters measured on a 2D radiograph could reflect 3D bone micro-architecture and optimize the acquisition conditions of the radiographic images (spatial resolution, energy and so on) for this purpose. Forty calcaneum samples prepared at the CHU in Nîmes, including two cortical bones, were imaged by 3D synchrotron micro-CT at 15 µm. This required management of a very large quantity of data (up to 1024x1024x3000 voxels per volume). The so-obtained 3D images were used both to extract 3D architecture parameters and to simulate radiographic projections using the LETI’s SIMBAD software
Results
This study made it possible to select a small number of parameters (co-occurrence, mathematic morphology, fractal dimension and so on) well correlated to the architectural measurements. It was shown that the variance of some 3D architecture parameters (bone surface to bone volume, trabecular thickness ....) could be explained at up to 95% by two texture parameters used in the multiple regression models
Collaborations and acknowledgements
This work was done in collaboration in the framework of a RNTS project with the CEA-LETI Grenoble, CHU-Nîmes, CHU-Lille, and DMS Nîmes.