Nonlinear Ultrasound Through-Transmission for Evaluating Porosity in Bone-Mimicking Phantoms

This study investigates the application of a nonlinear ultrasound through-transmission technique for the assessment of bone quality in the context of osteoporosis screening. Aluminum foam phantoms, fabricated with controlled variations in pore size (Pores Per Inch, PPI) and relative density (RD), were employed to simulate the microstructural characteristics of trabecular bone. Nonlinear wave propagation at 11.25 MHz was analyzed across samples with 10, 20, and 40 PPI and RD ranges of 4-6% and 8-10%. Experimental results revealed that low-PPI, high-RD structures exhibited significantly greater energy transmission, consistent with osteoporotic bone morphology, whereas high-PPI foams demonstrated pronounced attenuation, mimicking healthy trabecular architecture. The method shown high sensitivity to microstructural differences, underscoring its potential as a noninvasive, radiation-free modality for early osteoporosis detection. Future studies should focus on comparing the diagnostic performance of nonlinear versus linear ultrasound techniques for osteoporosis screening. Moreover, validation using biological bone specimens is crucial to improve diagnostic precision and reinforce the method's clinical relevance.