Effects of phase cancellation on broadband ultrasonic attenuation for in vitro human trabecular bone using a 2-D synthetic array

The average BV/TV, TB.Th and Tb.Sp for the trabecular bone are 0.154±0.052, 0.203±0.025 mm and 0.812±0.151 mm, respectively. After normalization with sample thickness, the average normalized BUA (nBUA) is 24.8±9.5 dB/MHz/cm and 19.2±5.5 dB/MHz/cm for PS and PI respectively. PS nBUA is significantly different than PI BUA (paired t-test, p<0.0001). On average, PS nBUA is 28.5% higher than PI BUA, and linear regression shows that PS nBUA can explain 81.2% of the variability in PI nBUA. Both PI nBUA and PS nBUA are highly correlated with BV/TV with coefficients of R=0.911 and R=0.898 (p<0.0001), respectively. Both PI nBUA and PS nBUA are also highly correlated with Young's modulus with coefficients of R=0.906 and R=0.822 (p<0.0001), respectively. Results show that phase cancellation does have a significant effect on BUA. However, both PS nBUA and PI nBUA correlate well with the structural parameter, BV/TV and mechanical strength parameter, Young's modulus.