Error compensation method for improving the accuracy of biomodels obtained from CBCT data

Abstract

This paper presents a method of improving the accuracy of the tridimensional reconstruction of human bone biomodels by means of tomography, with a view to finite element modelling or surgical planning, and the subsequent manufacturing using rapid prototyping technologies. It is focused on the analysis and correction of the results obtained by means of cone beam computed tomography (CBCT), which is used to digitalize non-superficial biological parts along with a gauge part with calibrated dimensions. A correction of both the threshold and the voxel size in the tomographic images and the final reconstruction is proposed. Finally, a comparison between a reconstruction of a gauge part using the proposed method and the reconstruction of that same gauge part using a standard method is shown. The increase in accuracy in the biomodel allows an improvement in medical applications based on image diagnosis, more accurate results in computational modelling, and improvements in surgical planning in situations in which the required accuracy directly affects the procedure's results. Thus, the subsequent constructed biomodel will be affected mainly by dimensional errors due to the additive manufacturing technology utilized, not because of the 3D reconstruction or the image acquisition technology.