Zhao Jingxin, Zhai Fei, Cheng Jun, He Qiong, Luo Jianwen, Yang Xueping, Shao Jinhua, Xing Huichun
Beijing Ditan Hospital, Capital Medical University, Beijing, China.
Hisky Medical Technology Co., Ltd, Beijing, China.
PLoS One. 2017 Jan 20;12(1):e0170073. doi: 10.1371/journal.pone.0170073. eCollection 2017.
Transient elastography quantifies the propagation of a mechanically generated shear wave within a soft tissue, which can be used to characterize the elasticity and viscosity parameters of the tissue. The aim of our study was to combine numerical simulation and clinical assessment to define a viscoelastic index of liver tissue to improve the quality of early diagnosis of liver fibrosis. This is clinically relevant, as early fibrosis is reversible. We developed an idealized two-dimensional axisymmetric finite element model of the liver to evaluate the effects of different viscoelastic values on the propagation characteristics of the shear wave. The diagnostic value of the identified viscoelastic index was verified against the clinical data of 99 patients who had undergone biopsy and routine blood tests for staging of liver disease resulting from chronic hepatitis B infection. Liver stiffness measurement (LSM) and the shear wave attenuation fitting coefficient (AFC) were calculated from the ultrasound data obtained by performing transient elastography. Receiver operating curve analysis was used to evaluate the reliability and diagnostic accuracy of LSM and AFC. Compared to LSM, the AFC provided a higher diagnostic accuracy to differentiate early stages of liver fibrosis, namely F1 and F2 stages, with an overall specificity of 81.48%, sensitivity of 83.33% and diagnostic accuracy of 81.82%. AFC was influenced by the level of LSM, ALT. However, there are no correlation between AFC and Age, BMI, TBIL or DBIL. Quantification of the viscoelasticity of liver tissue provides reliable measurement to identify and differentiate early stages of liver fibrosis.
瞬时弹性成像可量化机械产生的剪切波在软组织中的传播，其可用于表征组织的弹性和黏度参数。我们研究的目的是结合数值模拟和临床评估来定义肝组织的黏弹性指数，以提高肝纤维化早期诊断的质量。这在临床上具有相关性，因为早期纤维化是可逆的。我们建立了一个理想化的肝脏二维轴对称有限元模型，以评估不同黏弹性值对剪切波传播特性的影响。根据99例因慢性乙型肝炎感染导致肝病分期而接受活检和常规血液检查的患者的临床数据，验证了所确定的黏弹性指数的诊断价值。通过瞬时弹性成像获得的超声数据计算肝脏硬度测量值（LSM）和剪切波衰减拟合系数（AFC）。采用受试者工作特征曲线分析来评估LSM和AFC的可靠性和诊断准确性。与LSM相比，AFC在区分肝纤维化早期阶段（即F1和F2期）方面具有更高的诊断准确性，总体特异性为81.48%，敏感性为83.33%，诊断准确性为81.82%。AFC受LSM、ALT水平的影响。然而，AFC与年龄、体重指数、总胆红素或直接胆红素之间无相关性。肝组织黏弹性的量化为识别和区分肝纤维化早期阶段提供了可靠的测量方法。
