高频超声影像肝脏包膜几何特征定量评价患者肝硬化程度

Geometric features of liver capsule on high-frequency ultrasonic images in quantitatively evaluation of liver cirrhosis

目的探讨基于高频超声图像的肝脏包膜线几何特征定量评价乙型肝炎肝硬化程度的可行性。方法收集48例轻、中、重度乙型肝炎肝硬化患者(轻度肝硬化组、中度肝硬化组、重度肝硬化组)及20名正常志愿者(正常对照组)肝包膜的二维高频声像图,结合人工监督与梯度优化方法获取包膜线及其形状控制点,提取包膜线的连续线段数、形状控制点的夹角均值及夹角方差3个参数,分别评估肝包膜轮廓线的连续性和平滑度。结果随着肝硬化程度的逐渐加重,连续线段长度和达到成像切面总宽度的80%时所需要的线段数量逐渐增多,夹角均值和方差也逐渐增大;除中、重度肝硬化组间的线段数量差异无统计学意义外(P=0.149),其余组别各参数的比较差异均有统计学意义(P<0.05)。结论肝包膜的几何特征分析可较准确地诊断不同程度肝硬化,可望为肝硬化的非侵入性评估提供一种量化处理方法。

Objective To discuss the feasibility of quantitative evaluation of degree of liver cirrhosis with liver capsule geornetric features of high-frequency ultrasonic images.Methods Totally 48 patients with mild,moderate,severe liver cirrhosis（mild liver cirrhosis group,moderate liver cirrhosis group,severe liver cirrhosis group） and 20 healthy volunteers（control group） underwent two-dimensional high-frequency ultrasonography.Lines of liver capsule and their shape-control points were obtained,and continuous line numbers of liver capsule,angle mean and angle variance of the shape-control points were extracted using manual supervision and gradient optimization methods to assess the continuity and smooth of liver capsule.Results With the increasing degree of liver cirrhosis,continuous line numbers,the sum of the length of which reached 80%of the total width of the image,increased gradually,and the angle mean and angle variance increased too.Except that there were not significant differences of line numbers between moderate liver cirrhosis group and severe liver cirrhosis group（P = 0.149）,there were significant differences between any other two groups（P〈0.05）.Conclusion Geometric features analysis of liver capsule can accurately assess the degree of liver cirrhosis,and can be expected to provide a new method for the non-invasive and quantitative evaluation of the liver cirrhosis.