Evaluation Method Of Cortical Bone And Cancellous Bone Strength Based On Quantitative Ultrasound

Osteoporosis is a common degenerative disease. With the aging of Chinese society, the number of osteoporotic population increases year by year. When osteoporotic fractures occur, patients and their families will carry a heavy burden of life and economic, affecting the quality of life and happiness index. At the same time, the financial implications of these huge increases in the number of osteoporotic fractures will have considerable impact on health care and social welfare systems. Screening for osteoporosis is the most effective and economical and feasible measure to prevent osteoporotic fractures (WHO). Currently, dual energy X ray (DEXA) is considered as the gold standard for bone condition assessment and osteoporosis diagnosis, which can be used to detect bone mineral density (BMD). However, the occurrence of osteoporotic fracture is due to the decrease of bone strength, which leads to brittle fracture of bone. It is known that the bone strength is not only related to bone mass BMD, but also to the microstructure of bone. At present, our country is vigorously promoting community medical construction, building a more reasonable social security system. Howerer, DEXA can not satisfy the demand of the mass screening and long-term dynamic tracking measurement due to their high expense, complex operation and X-ray exposure. Quantitative ultrasound (QUS) can not only detect the bone "quantity" information (BMD), but also the reaction of "quality" of the information (skeletal bone microstructure), and QUS has the advantages of low cost, high speed, portable, non ionizing radiation. It was considered diagnostic method of the most economical and effective alternative DEXA. According to different measurement methods and different parts of the measurement, the diagnosis of QUS in bone state is divided into cortical bone strength and cancellous bone strength evaluation method. However, the bone strength of cortical bone and cancellous bone strength study there are many problems, such as the low correlation between SOSFAS and DEXA, which is due to the low recognition rate of SOSFAS. Similarly, the cancellous bone porosity (the important indexes of bone strength bone size) diagnosis and evaluation, lack of effective evaluation model. In this study, we put forward an improved algorithm to improve the correlation between SOSFAS and DEXA measurement results, in view of the low recognition rate of cortical bone strength evaluation parameters (SOSFAS). At the same time, ultrasonic power spectrum based on the ultrasonic characteristic parameters of APF for evaluating the size of pine bone porosity, research and develop the multi parameter fusion assessment of cancellous bone strength bone model, through clinical trials to verify the effectiveness of the new model. The main research contents arc as follows:In view of cortical bone strength evaluation research, the following points arc mainly concentrated in the following two points:1. Building a test platform for bone strength of cortical bone double transceiver probe based on the structureIn view of bone health screening and general applicability and low cost, this research is designed based on a double transceiver probe structure of portable cortical bone (radius and tibia bone density testing site). The hardware cost of the instrument is less than 4000 ￥, the weight is less than 1.5 kg, the measurement repeatability is good (CVRMS=0.18), the measurement accuracy reaches the level of similar products, to meet the needs of osteoporosis screening and screening.2. Cortical bone strength evaluation parameters SOSFAS recognition algorithm researchAccording to the characteristics of the cortical bone parameters of SOSFAS high error rate problem, this study proposes a dynamic time window algorithm based on static time window, with double transceiver probe structure, we propose a simple and effective SOSFAS algorithm. The algorithm can effectively eliminate the influence of soft tissue thickness on the SOSFAS measurement results, and it has a better shielding effect on the system delay. Clinical trials have shown that the 1/3 measurement results of SOSFAS at the distal radius DEXA and the same location of the distal radius are significantly correlated (r=0.81, P<0.05), and the measurement accuracy is improved compared with the traditional SOSFAS measurement algorithm.According to the evaluation of cancellous bone strength, the main focus is on the following two points:3. Study on the ultrasonic evaluation parameters of cancellous bone microstructureIt is critical for trabecular microstructure of cancellous bone on bone strength influence. The theoretical study shows that the ultrasonic characteristic parameters can reflect the micro information, such as the direction, the thickness, the distance and the quantity of the trabecular bone. However, the research on the porosity of the trabecular bone is not too much. In the in vitro experiments, some researchers found that ultrasound scattering coefficient has a high correlation with the porosity of cancellous bone, but lack of effective clinical experimental data support in vivo experiment. In view of the application of ultrasonic power spectrum parameters in the detection of porosity in the composite, this paper adopts ultrasonic power ultrasonic transmission spectrum of the signal, study the relationship between ultrasonic power spectrum and characteristic parameters of cancellous bone porosity. Through the discovery of 50 clinical ultrasonic wave signal acquisition and analysis, ultrasonic power spectrum characteristic parameters of APF, PF, FB, LI-L4 DEXA and lumbar BMD measurement results show different correlation, among them, APF was significantly associated with lumbar spine BMD (r=-0.71, P<0.05). In addition, APF and BMD showing a linear relationship (especially the index relationship) is higher than that of APF, SOS and BUA, better discrimination of less bone holes and osteoporosis groups resolution, so it can be used as a new characteristic parameter evaluation of cancellous bone strength bone.4. Study on the evaluation model of cancellous bone strengthIn recent years, the cancellous bone trabecular structure has attracted more and more concerns, researchers have proposed a variety of new ultrasound evaluation parameters, but more of a theoretical model of single parameter. Therefore, this study collected 50 cases of the experimental data, a multi parameter linear regression method, constructed APF, BUA and SOS of bone strength evaluation model based on multi parameter, and the effectiveness of 52 cases of clinical trials to verify the model. The results show that using APF, BUA, SOS or BUA+SOS single parameter combination evaluation of BMD, DEXA and the maximum correlation is only 0.89, the minimum is 8.2% RMSE; when using APF+BUA+SOS multi parameter fusion BMD, correlation of up to 0.91, and 7.8% RMSE. At the same time,52 cases of clinical verification results show that the APF+BUA+SOS evaluation model can be used to improve the accuracy of clinical assessment of cancellous bone bone strength.Conclusion:the comprehensive strength evaluation method of cortical bone and cancellous bone bone strength evaluation method, can realize the peripheral bone (tibia and calcaneus, phalanx, radius) of the comprehensive evaluation, to provide theoretical and technical support for the construction of health assessment and health promotion of small closed loop system, so as to achieve the purpose of comprehensive evaluation of human bone health.