Densitometry test of bone tissue: Validation of computer simulation studies

Bone densitometry measurements are performed to predict the fracture risk in bones. However, the sensitivity of these predictions are not satisfactory. One of the explanations is that densitometry ignores the (architectural) structural aspects of the bone. The effects of varying architectural parameters on the densitometry parameters can be effectively assessed by considering a 3-D image of a bone and vary the bone structure parameters in a controlled manner and determine the consequence of these changes on a simulated (virtual) densitometry analysis. In this paper we present such a computer simulation of densitometry analysis of bone. The simulation allows quantification of densitometry parameters, such as BMD and BMC, on the basis of computed tomography bone scans. The aim of the presented study is the evaluation of our method by comparing its results to the results from real densitometry (DEXA) tests. For the evaluation we selected three femoral bones. These items were CT scanned and individual computer models were created. In addition, the densitometry parameters of these items were assessed by a clinical DEXA scanner. The densitometry parameters obtained from the simulations were very close to the results from the DEXA densitometry measurements. We therefore conclude that our method can be employed in the research on the influence of changes in bone structure on densitometry test results.