Comparison of HR-pQCT- and microCT-based finite element models

The bedrock of developing robust Virtual Physiological Human is a robust and accurate digital transformation of existing medical procedures. The development of high-resolution imaging systems such as HR-pQCT (High Resolution Peripheral Quantitative Computed Tomography) has provided clinicians with a powerful tool for a 3D visualisation of patients’ internal bone structures (e.g. trabecular regions) which are prone to the aging-related diseases such as osteoporosis. Building on HR-pQCT imaging advancement, the engineering FE (Finite Element) technique has also been incorporated to predict the mechanical characteristics of the monitored trabecular bone structures under certain loading scenarios.

 

Nevertheless, the reliability of the FE results are strongly coupled with the accuracy of the assessment of the trabecular bone structure from the clinical images. In this study we investigate the accuracy of HR-pQCT-based FE predictions with respect to those generated from high-resolution scans of the same specimens acquired with micro-Computed Tomography (MicroCT). This study focused on human cadaveric calcaneum, where the mechanical and microstructural properties of the trabecular tissue play a dominant role. A range of morphological and mechanical properties was evaluated for each sample (see figure).

 

Figure: An example of (a) microCT-based trabecular model and (b) its corresponding HR-pQCT-based microstructure

 

In summary, we have found that the morphology, and as a results the mechanical properties, of HR-pQCT-based models are considerably different to their corresponding microCT models. Our investigation has shown that this disparity is strongly attributed to the procedure to analyse the low-resolution images and to convert them to computational models. Further analyses are required to address whether more sophisticated image processing techniques may improve the accuracy of clinical models of the trabecular bone of the calcaneus.

 

Full text :

Alsayednoor, J., Metcalf, L., Rochester, J., Dall’Ara, E., McCloskey, E., Lacroix, D.Comparison of HR-pQCT- and microCT-based finite element models for the estimation of the mechanical properties of the calcaneus trabecular bone Biomechanics and Modeling in Mechanobiology (2018), pp 1-16

DOI: https://doi.org/10.1007/s10237-018-1051-6