Impact of Cortical Bone Thickness on the Parameters of Fast and Slow Ultrasound Wave based on 2-D Simulation

Abstract

Quantitative Ultrasound (QUS) has been introduced to measure the quality of human bones using ultrasound and become one of the prevention methods for Osteoporosis diseases. Because of the porous composition inherent in human cancellous bone, the generation of both fast and slow waves occurs, and these waves exhibit a distinct association with the cancellous bone structure, particularly the extent of porosity. Nonetheless, the presence of these waves is also contingent upon the anisotropy of cancellous bone, and it is noteworthy that most human cancellous bones are enveloped by cortical bone, which may influence the parameters of the fast and slow waves. Therefore, the aim of this study is to perform a 2-Dimensional (2-D) simulation utilizing the through transmission (TT) measurement method. The primary focus is to examine the impact of cortical thickness on the parameters of both the fast and slow waves. The cortical thickness will be added to the cancellous bone models and the thickness will be varied. Then, the fast and slow wave parameters will be compared in terms of correlation coefficient to identify which wave is affected more. The result shows that the cortical thickness causes increasing in attenuation and velocity for both fast and slow waves. The increase in attenuation is due to sonometry effects while the different longitudinal velocities of water and bone material may contribute to the behaviors for phase velocity measurements. However, the fast wave shows more correlation with the cortical thickness for attenuation (R2 = 0.76) and phase velocity (R2 = 0.77) parameters. This is due to fast wave corresponding to the solid structure and increasing cortical thickness also increase the solid structure. Thus, analyzing fast waves against human cancellous bone, cortical bone thickness needs to be considered to ensure accurate measurements.