Practical problems in the preparation, acquisition and image processing of a cortical phantom

Aims The use of phantoms for micro-CT in biomedical research was already presented in literature for segmentation procedure, repeatability measures, densitometric calibration and in general for the improvement of micro-CT images [1-4]. Moreover, a high quality image was required to improve the accuracy of histomorphometric measurements. In particular these studies were performed for trabecular bone. The interest in the study of trabecular bone was due to the complex structure of this compound with thin trabeculae. In fact the quality of the image was dependent by the beam hardening and partial volume effects. The cortical bone was characterized by a thick structure with pores. A similar study could be performed for the cortical bone in order to find the limitations in the acquisition and reconstruction processes. Therefore, no phantoms commercially available were found. The aims of the present work were: a) the study of the limitation of the realization of a phantom which reproduce the structure of cortical specimens; b) the analysis of the effects on the image quality caused by the interaction between a polychromatic X-ray beam and the phantom in the acquisition process; c) the analysis of the effect of the application of a Gaussian filter on the signal to noise ratio in the reconstruction process.