基于超声背散射信号分析松质骨中的声阻抗

Analysis of Acoustic Impedance in Cancellous Bone using Ultrasonic Backscatter Signal

采用背散射法,研究用声阻抗评价松质骨状况。对松质骨中的超声散射特性进行了分析和讨论,并将分析结果和Faran理论模型进行比较分析;最后对理论和实验所得的牛胫骨、人离体跟骨和人在体跟骨松质骨中的声阻抗分布进行了分析讨论。结果表明松质骨中的声阻抗随入射频率的增加而非线性的增加,理论和实验结果是一致的。当患有骨质疏松时,松质骨密度将减小,因此,与健康松质骨中的声阻抗相比,患骨质疏松松质骨中的声阻抗较小。

Assessment of cancellous bone was presented using the acoustic impedance of the backscattered ultrasonic signal. The ultrasonic scattering characteristics in cancellous bone were analyzed and compared with Faran theory. The acoustic impedance of backscatter signals from bovine tibiae, human calcaneus in vitro and in vivo were measured and discussed, respectively. The experimental and theoretical results showed that acoustic impedance is a non-linear function of frequency, increasing with frequency. A good agreement was obtained in acoustic impedance of the experimental result and theoretical model. When the bone suffered from osteoporosis, the density will reduce. Therefore, compared with the acoustic impedance in the normal cancellous bone, the osteoporotic cancellous bones have small acoustic impedance. According to the measurement of acoustic impedance, the status of cancellous bone and the degree of osteoporotic fracture risk may be assessed.