Preeminent Medical Photonics Education & Research, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan.
Institute of Engineering, Tokyo University of Agriculture and Technology, Koganei-shi, Tokyo 184-8588 Japan.
Ultrasound Med Biol. 2024 Apr;50(4):592-599. doi: 10.1016/j.ultrasmedbio.2024.01.002. Epub 2024 Jan 17.
Hepatic fibrosis has recently been evaluated using ultrasonography or magnetic resonance elastography. Although the shear wave velocity (SWV) obtained using point shear wave elastography (pSWE) provides a valuable measure of fibrosis, underlying steatosis may affect its measurement.
Using hepatic fibrosis samples, this study evaluated the effect of steatosis on the shear wave velocity of pSWE (V) and viscoelastic properties (assessed by dynamic mechanical analysis) of rat liver. Fifty rats with various grades of steatosis and fibrosis underwent open abdominal in vivo V measurements using a commercial ultrasound scanner. The mechanical properties of hepatic tissue were also characterized under ex vivo conditions using dynamic mechanical analysis and the Zener model of viscoelasticity.
Fibrosis and steatosis progression influenced V and elasticity. The SWV computed using the Zener model and V showed a substantial correlation (r > 0.8). Fibrosis progression increased SWV. Steatosis was also related to SWV. Steatosis progression obscured the SWV change associated with fibrosis progression.
We conclude that steatosis progression affects the evaluation of fibrosis progression. This finding could aid discrimination of non-alcoholic steatohepatitis from non-alcoholic fatty liver disease using SWV.
肝纤维化最近已通过超声或磁共振弹性成像进行评估。尽管使用点剪切波弹性成像（pSWE）获得的剪切波速度（SWV）可提供纤维化的有价值的测量值，但潜在的脂肪变性可能会影响其测量。
本研究使用肝纤维化样本，评估了脂肪变性对 pSWE（V）剪切波速度和大鼠肝粘弹性特性（通过动态力学分析评估）的影响。五十只不同程度脂肪变性和纤维化的大鼠在开放腹部的体内 V 测量中使用商业超声扫描仪进行了 V 测量。还使用动态力学分析和粘弹性的泽纳模型在体外条件下对肝组织的机械性能进行了特征描述。
纤维化和脂肪变性的进展影响 V 和弹性。泽纳模型计算的 SWV 和 V 之间存在很强的相关性（r>0.8）。纤维化进展增加了 SWV。脂肪变性也与 SWV 相关。脂肪变性的进展掩盖了与纤维化进展相关的 SWV 变化。
我们得出结论，脂肪变性的进展会影响纤维化进展的评估。这一发现可能有助于使用 SWV 区分非酒精性脂肪性肝炎和非酒精性脂肪肝。
