Department of Imaging Sciences, University of Rochester Medical Center, Rochester, New York, USA.
Department of Electrical and Computer Engineering, University of Rochester, Rochester, New York, USA.
Ultrasound Med Biol. 2019 Apr;45(4):895-901. doi: 10.1016/j.ultrasmedbio.2018.12.002. Epub 2019 Jan 23.
Shear wave propagation in the liver has been a robust subject of research, with shear wave speed receiving the most attention. The correlation between increased shear wave speed and increased fibrosis in the liver has been established as a useful diagnostic tool. In comparison, the precise mechanisms of shear wave attenuation, and its relation to diseased states of the liver, are less well-established. This study focused on the hypothesis that steatosis adds a viscous (lossy) component to the liver, which increases shear wave attenuation. Twenty patients' livers were scanned with ultrasound and with induced shear wave propagation, and the resulting displacement profiles were analyzed using recently developed estimators to derive both the speed and attenuation of the shear waves within 6-cm regions of interest. The results were compared with pathology scores obtained from liver biopsies taken under ultrasound guidance. Across these cases, increases in shear wave attenuation were linked to increased steatosis score. This preliminary study supports the hypothesis and indicates the possible utility of the measurements for non-invasive and quantitative assessment of steatosis.
剪切波在肝脏中的传播一直是研究的热点，其中剪切波速度受到了最多的关注。剪切波速度的增加与肝脏纤维化的增加之间的相关性已被确立为一种有用的诊断工具。相比之下，剪切波衰减的确切机制及其与肝脏病变状态的关系尚未得到很好的建立。本研究的重点是假设脂肪肝会给肝脏增加一个粘性（损耗性）成分，从而增加剪切波衰减。我们对 20 名患者的肝脏进行了超声扫描和诱导剪切波传播，并用最近开发的估计器对产生的位移轮廓进行了分析，以在 6cm 的感兴趣区域内得出剪切波的速度和衰减。结果与超声引导下肝活检获得的病理评分进行了比较。在这些病例中，剪切波衰减的增加与脂肪肝评分的增加有关。这项初步研究支持了这一假设，并表明这些测量值可能可用于非侵入性和定量评估脂肪肝。
