Combined XA/CT Imaging for Bone Density and Elasticity Evaluation: A Simulation Study

Osteoporosis is a significant public health concern that affects old adults and individuals with certain medical conditions. In this work, we demonstrate the proof of the principle of combining the emerging new radiological imaging technique, X-ray-induced acoustic (XA) imaging, and X-ray computed tomography (CT) for bone density and elasticity evaluation. This combined method is intended for use in single scanner that can perform both XA imaging and CT imaging simultaneously for the purpose of providing accurately registered anatomical localization of structures seen in the CT image to extract the elasticity information in XA imaging. We demonstrate that our nonlinear optimization algorithm can acquire the speed of sound information for bone. By combining the speed of sound and density information from CT, we can calculate the elasticity with an error of less than 1%. We conclude that using CT information as prior information is a feasible way to obtain elasticity information in XA imaging. These findings enable more accurate osteoporosis diagnosis through both bone density and bone strength evaluation using one integrated system in the future.