We thank Ferraioli et al. for their interest in our article. We appreciate their concern, and would like to provide more details about how we measured liver stiffness using real-time tissue elastography. With regard to the first question, we previously described how we set the region of interest (ROI) for measuring elasticity by real-time tissue elastography. The area of the ROI placed on both the liver and the spleen parenchyma was within 2 x 1 cm. The size of the ROI in the small vessels was usually within 0.3 X 0.5 cm. We used mean values derived from five measurements. We identified from these that the elastic ratio is not influenced by the size of the ROI. The maximum and minimum lengths of the ROI measured in our previous study were 1.90 ± 0.12 (range, 1.5-2.0) and 0.90 ± 0.11 (range, 0.6-1.0) cm for the liver and spleen parenchyma, and 0.44 ± 0.07 (range, 0.3-0.5) and 0.28 ± 0.01 (range, 0.2-0.3) cm for small vessels.2 We also previously found that interobserver agreement in determining fibrosis stage at different liver sites and the elastic ratio calculated by the two examiners closely correlated, and did not significantly differ. This evidence indicated that a small variation in the size of the ROI would not affect the value of the elastic ratio determined using real-time tissue elastography.
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机译：我们感谢Ferraioli等。对他们对我们文章的兴趣。我们感谢他们的关注，并希望提供更多有关我们如何使用实时组织弹性成像技术测量肝硬度的详细信息。关于第一个问题，我们先前描述了如何设置感兴趣区域（ROI）以通过实时组织弹性成像技术测量弹性。放置在肝脏和脾实质上的ROI面积在2 x 1 cm之内。小血管中ROI的大小通常在0.3 X 0.5 cm之内。我们使用了从五次测量得出的平均值。我们从中发现，弹性比不受ROI大小的影响。在我们先前的研究中，测量的ROI的最大和最小长度分别为1.90±0.12（范围1.5-2.0）和0.90±0.11（范围0.6-1.0）cm（肝脏和脾实质），以及0.44±0.07（范围， 0.3-0.5）和0.28±0.01（范围0.2-0.3）厘米（小血管）。2我们先前还发现观察者之间在确定不同肝脏部位的纤维化分期方面的一致性与两位检查者计算出的弹性比密切相关，没有明显的不同。该证据表明，ROI大小的微小变化不会影响使用实时组织弹性成像确定的弹性比值。
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