Ultrasound backscattering from cancellous bone in vivo

Abstract

Osteoporosis is a musculoskeletal disease characterized by a loss of bone mass and a deterioration of trabecular bone microarchitecture. In recent years, significant progress has been made in the quantitative ultrasound technique, and it has become well established as a noninvasive tool for the assessment of bone status. This report will show the ultrasonic backscatter theory in cancellous bone, analyze the ultrasonic backscattering signals, and to investigate correlations among backscatter parameters and bone mineral density (BMD) in vivo. Ultrasonic backscattering measurements were performed on 1226 subjects (601 males and 625 females) at the right calcaneus in vivo using the novel ultrasonic backscatter bone system. Then, the subjects underwent DXA for the BMD at sites located on the lumbar spine (sBMD) and left hip (hBMD). Spectral centroid shift (SCS), mean trabecular bone spacing (Tb.Sp), backscatter coefficient (BC), and apparent integral backscatter coefficient (AIB) were calculated at the central frequencies of 3.5 and 5.0 MHz. Linear regression showed that the SCS at 3.5 MHz exhibited negative correlations with the sBMD (R=−0.66) and hBMD (R=−0.64). The SCS at 5.0 MHz was also found to be closely related to the sBMD (R=−0.68) and hBMD (R=−0.66). Tb.Sp at 3.5 MHz and 5.0 MHz exhibited negative correlations with the sBMD (R=−0.74) and hBMD (R=−0.66).The correlations between backscatter parameters and BMD were found to be statistically significant in both the male and female groups.