Numerical Assessment of Microwave Bone Imaging: Reconstruction of Realistic Phantoms for Diagnosing Different Bone Diseases

Microwave imaging (MWI) can be used as an alternative modality for monitoring human bone health. So far, studies on microwave bone imaging have considered bone as a homogenous tissue; however, bone is composed of a cortical and trabecular layer having significantly different dielectric properties and microarchitecture. The trabecular bone is more susceptible to diseases like osteoporosis. Contrarily, osteoarthritis, another significant bone disease, has a more severe impact on cortical bone. Therefore, considering cortical and trabecular bone as two different bone types is of paramount importance for diagnosing different bone diseases. To this end, this study has made the first attempt to design and reconstruct the cortical and trabecular bone phantoms separately. The bone phantoms were designed as a single-layered heel-shaped structure. A Distorted Born Iterative Method (DBIM) approach in combination with the Iterative Method with Adaptive Thresholding for Compressed Sensing (IMATCS) has been employed for solving the electromagnetic inverse scattering problem. The simulation results have shown that the cortical and the trabecular bone can be distinguished based on the reconstructed dielectric properties even for low values of the signal-to-noise ratio (SNR). The findings of this study have shown that the adopted approach can be used to reconstruct the cortical and trabecular bones with reasonable accuracy and hence aid in monitoring different bone diseases based on their reconstructed dielectric properties.