基于超声射频信号的脂肪肝评估研究

发布时间：2018-02-28 07:25

本文关键词： 非酒精性脂肪肝组织定征衰减系数质心频率　出处：《深圳大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着人民生活水平的提高,膳食结构中不断增加的含脂量及缺乏运动的生活方式,非酒精性脂肪肝(Nonalcoholic fatty liver,NAFLD)呈现发病率上升、且年轻化的趋势。虽然非酒精性脂肪肝被公认为属于良性病变,轻度时并无明显症状,但它是许多慢性肝脏疾病的早期阶段。一旦从单纯性脂肪肝发展为脂肪性肝炎,如果不及时治疗,进而会引发肝纤维化和肝硬化。因而,脂肪肝的早期诊断对于脂肪肝的临床治疗起着关键作用。本文通过采集超声B模式的射频(Radio frequency,RF)回波数据,然后对其采用组织定征的方法提取特征参数,对离体大鼠脂肪肝模型进行评估研究。众所周知,RF信号内含有丰富的微观组织信息,因此通过不同的信号处理方式可计算组织的质心频率、谱斜率、截距以及中频幅度等参数。然后利用统计分析的方式并利用参数的值域分布对大鼠离体脂肪肝组织进行评估研究。本文中,通过仿真平台生成不同衰减系数的仿真数据,然后用本实验的参数提取算法处理仿真数据,并将处理结果与仿真设置参数对比,验证并优化算法。再次,通过对不同衰减系数的仿真参数进行统计分析,得出各参数的理论变化趋势。最后,将算法应用于离体大鼠脂肪肝数据处理中,提取各参数并进行统计分析,接着将结果与病理切片分析结果进行评估分析。结果表明:质心频率、频谱斜率、截距以及中频幅度都有一定的分期效果,但是质心频率与频谱斜率的分期效果较其它参数更优。
[Abstract]:With the improvement of people's living standard, the increasing amount of fat in dietary structure and the lack of exercise lifestyle, the incidence of nonalcoholic fatty liver with nonalcoholic fatty plus NAF LDD increased. Although nonalcoholic fatty liver is recognized as a benign disease and has no obvious symptoms in mild stage, it is the early stage of many chronic liver diseases. Once it develops from simple fatty liver to fatty hepatitis, Early diagnosis of fatty liver plays a key role in the clinical treatment of fatty liver if it is not treated in time, which can lead to liver fibrosis and cirrhosis. Then the characteristic parameters were extracted by tissue characterization, and the model of fatty liver in vitro was evaluated. It is well known that the RF signal contains abundant microstructural information. Therefore, the centroid frequency and spectral slope of the tissue can be calculated by different signal processing methods. The parameters such as intercept and if amplitude are used to evaluate the fatty liver tissue in vitro using statistical analysis and the range distribution of the parameters. In this paper, the simulation data of different attenuation coefficients are generated by the simulation platform. Then the parameter extraction algorithm of this experiment is used to process the simulation data, and the processing results are compared with the simulation setting parameters to verify and optimize the algorithm. Thirdly, through the statistical analysis of the simulation parameters with different attenuation coefficients, Finally, the algorithm is applied to the data processing of rat fatty liver in vitro, and the parameters are extracted and analyzed statistically. Then the results were evaluated with the results of pathological section analysis. The results showed that the centroid frequency, spectral slope, intercept and intermediate frequency amplitude all had certain staging effect. But the centroid frequency and spectrum slope are better than other parameters.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB559;R575.5

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