Assessment of bone mineral content from 3D synchrotron radiation microtomography images

Synchrotron Radiation /spl mu/CT (SR /spl mu/CT) may provide 3D images with spatial resolution as high as one micrometer. The SR /spl mu/CT system developed at ESRF was already used to quantify trabecular bone architecture in bone samples. In this work we propose for the first time to use SR /spl mu/CT to assess the mineral content in bones. This quantification is possible thanks to the monochromaticity and high photon flux of the X-ray beam extracted from synchrotron radiation. For this purpose, we relate the reconstructed gray levels of the images to a degree of mineralization in bone. We propose a calibration method to estimate the 3D distribution of hydroxyapatite concentrations within the sample. This method if compared to a reference microradiography technique. Finally, we illustrate the possibilities of the method on 3D images of human biopsies from osteoporotic patients before and after a treatment with bisphosphonates.