一种双能X线骨密度仪的测量算法研究

Research on a Measurement Algorithm of Dual Energy X-Ray Absorptiometry

双能X线骨密度仪测量骨密度是用2种不同能量的X线对人体进行成像,根据软组织和骨骼对不同能量的透过性不同,排除图像中软组织的影响,求得人体骨密度值。为了提高双能X线骨密度仪测量骨密度的准确度,提出了一种基于对数拟合的改进算法。先对现有双能X线骨密度测量算法进行研究,介绍了目前常见的骨密度测量算法,包括理论公式计算法和拟合法。在此基础上,提出了一种基于对数拟合的改进算法。该算法拟合公式简单,拟合所需数据更少,更加符合骨密度值和X射线透过值之间的关系。最后通过实验,证明了该算法在实际测量中,可以有效排除骨密度测量过程中软组织的影响,准确度较高。

The dual energy X-ray absorptiometry uses X-rays of two different energies to image the human body. The different permeability of soft tissues and bones to different energies is used to obtain bone density value without influence of soft tissues. In order to improve the accuracy of dual-energy X-ray bone density measurement, an improved algorithm based on logarithmic fitting is proposed. The current common bone density measurement algorithms are introduced, including theoretical formula calculation methods and fitting methods. Based on this, an improved algorithm based on logarithmic fitting is proposed. The algorithm has a simple fitting formula, requires less fitting data, and is more in line with the relationship between the bone density value and the X-ray transmission value. Finally, through experiments, it is proved that this algorithm can effectively exclude the influence of soft tissue during the measurement of bone density in actual measurement, and the accuracy is higher.