Analysis of backscatter signals from bone using a two parameter and three parameter exponential fit

Abstract

Osteoporosis is a degenerative bone disease that causes normally porous bone tissue, called cancellous bone, to become more porous and weak. Ultrasonic techniques may be used to detect changes in cancellous bone caused by osteoporosis. The goal of the study is to determine if the decay in the amplitude of an ultrasonic backscatter signal from cancellous bone correlates with bone density. Ultrasonic backscatter measurements were performed on 29 specimens of cancellous bone prepared from the distal end of 5 human femurs. The backscatter amplitude decay constant was measured using a two parameter (BADC2) and three parameter (BADC3) exponential fit. Linear regression analysis was used to determine the correlation between BADC and bone density. BADC2 and BADC3 demonstrated highly significant (p < 0.001) linear correlations with bone density, however BADC2 yielded slightly stronger correlations (0.75 ? R ? 0.84) than BADC3 (0.64 ? R ? 0.76). The results of the study suggest that the decay in the amplitude of ultrasonic backscatter signals from cancellous bone may be sensitive to changes in bone caused by osteoporosis.