Relationships of quantitative ultrasound parameters with cancellous bone microstructure in human calcaneus in vitro

Abstract

Ultrasound parameters (attenuation, phase velocity, and backscatter), bone mineral density (BMD), and microarchitectural features were measured on 29 human cancellous calcaneus samples in vitro. Regression analysis was performed to predict ultrasound parameters from BMD and microarchitectural features. The best univariate predictors of the ultrasound parameters were the indexes of bone quantity: BMD and bone volume fraction (BV/TV). The most predictive univariate models for attenuation, phase velocity, and backscatter coefficient yielded adjusted squared correlation coefficients of 0.69-0.73. Multiple regression models yielded adjusted correlation coefficients of 0.74-0.83. Therefore attenuation, phase velocity, and backscatter are primarily determined by bone quantity, but multiple regression models based on bone quantity plus microarchitectural features achieve slightly better predictive performance than models based on bone quantity alone.

Relationships of linear and nonlinear ultrasound parameters with porosity and trabecular spacing in trabecular-bone-mimicking phantoms

“…18 Wear et al also found that the nBUA was highly correlated to the porosity (r ¼ À0.85) but not significantly to the trabecular spacing (r ¼ À0.22) in 29 human calcaneal trabecular bone samples. 16 As found in Figs. 3(a) and 3(b), the dependence of the SOS on the porosity and the trabecular spacing exhibited a behavior opposite to that of the nBUA.…”

“…15 Wear et al also observed that the SOS was negatively correlated with the porosity (r ¼ À0.77) and the trabecular spacing (r ¼ À0.25) in 29 human calcaneal trabecular bone samples. 16 As predicted by using Biot's theory for elastic wave propagation in fluid-saturated porous media, the slow wave velocity in trabecular bone increases with increasing porosity, and the fast wave exhibits an opposite dependence on the porosity. 17 Hence, the positive correlations of the SOS with the porosity and the trabecular spacing obtained in the present study underpins the fact that the signals transmitted through the phantoms consisting of water-saturated aluminum foams correspond to the slow wave.…”

“…These results may help explain findings by other researchers investigating the relationships of the nBUA with the microarchitectural parameters in human trabecular bone. 16,18 For instance, Padilla et al observed that the nBUA was highly correlated with the porosity (r ¼ À0.83) and the trabecular spacing (r ¼ À0.79) in 37 human femoral trabecular bone samples. 18 Wear et al also found that the nBUA was highly correlated to the porosity (r ¼ À0.85) but not significantly to the trabecular spacing (r ¼ À0.22) in 29 human calcaneal trabecular bone samples.…”

“…This finding is contrary to the behavior in human trabecular bone. 15,16 For instance, Wear et al reported that the phase velocity decreased monotonically with increasing porosity for porosities from 86% to 98% in 53 human calcaneal trabecular bone samples. 15 Wear et al also observed that the SOS was negatively correlated with the porosity (r ¼ À0.77) and the trabecular spacing (r ¼ À0.25) in 29 human calcaneal trabecular bone samples.…”

Correlations of linear and nonlinear ultrasound parameters with density and microarchitectural parameters in trabecular bone

“…5 The relationships of SOS and nBUA with BMD and microarchitectural parameters not only in human calcaneus but also in femur in vitro have been extensively reported by a number of authors. [6][7][8][9][10][11] In contrast, few authors investigated nonlinear ultrasonic behaviors of bone. [12][13][14][15][16][17][18] The nonlinear elastic parameter B/A is defined as the first-order pressure derivative of the elastic modulus (the bulk modulus for a fluid).…”