Usefulness of quantitative ultrasound in evaluating structural and mechanical properties of bone: Comparison of ultrasound, dual-energy X-ray absorptiometry, and mechanical testing of human phalanges in vitro.

none6INTRODUCTION: Ultrasound studies evaluating bone tissue generally concentrate on two parameters--velocity and attenuation. This study aimed to determine whether ultrasound signal analysis techniques could provide additional information on the structural and mechanical characteristics of bone. MATERIALS AND METHODS: In vitro measurements were made on 26 left index fingers from human cadavers. Ultrasound measurements at the distal metaphysis and epiphysis; dual-energy X-ray absorptiometry of the whole phalanx; micro-computed tomography at the distal quarter of the phalanx (that is, the distal epiphysis and metaphysis), and mechanical three-point bending tests were performed. Univariate and multivariate linear regression techniques were used to analyze the results. RESULTS: The ultrasound parameters, speed of sound and ultrasound peak amplitude correlated significantly with the three micro-computed tomography measures used to describe the characteristics of mineralized material (r=0.69-0.79, p<0.05). Low frequency ultrasound correlated significantly with micro-computed tomography parameters describing inter-trabecular or marrow spaces (r=0.68-0.78, p<0.05). Comparison of ultrasound parameters with geometric characteristics showed that while speed of sound and ultrasound peak amplitude were related to the cortical area, moment of inertia, and mechanical load (r=0.57-0.83, p< 0.05), the amplitude of the fastest part of the ultrasound signal and full width at 80% maximum of the low frequency peak were related to the relative area of the medullary canal (r=0.40-0.43, p