Early detection and diagnosis of liver fibrosis is of critical importance. Currently the gold standard for diagnosing liver fibrosis is biopsy. However, liver biopsy is invasive and associated with sampling errors and can lead to complications such as bleeding. Therefore, developing noninvasive imaging techniques for assessing liver fibrosis is of clinical value. Ultrasound has become the first-line tool for the management of chronic liver diseases. However, the commonly used B-mode ultrasound is qualitative and can cause interobserver or intraobserver difference. Ultrasound backscatter envelope statistics parametric imaging is an important group of quantitative ultrasound techniques that have been applied to characterizing different kinds of tissue. However, a state-of-the-art review of ultrasound backscatter envelope statistics parametric imaging for liver fibrosis characterization has not been conducted. In this paper, we focused on the development of ultrasound backscatter envelope statistics parametric imaging techniques for assessing liver fibrosis from 1998 to September 2019. We classified these techniques into six categories: constant false alarm rate, fiber structure extraction technique, acoustic structure quantification, quantile–quantile probability plot, the multi-Rayleigh model, and the Nakagami model. We presented the theoretical background and algorithms for liver fibrosis assessment by ultrasound backscatter envelope statistics parametric imaging. Then, the specific applications of ultrasound backscatter envelope statistics parametric imaging techniques to liver fibrosis evaluation were reviewed and analyzed. Finally, the pros and cons of each technique were discussed, and the future development was suggested.

中文翻译：

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用于肝纤维化表征的超声反向散射包络统计参数成像：综述

肝纤维化的早期检测和诊断至关重要。目前诊断肝纤维化的金标准是活检。然而，肝活检是侵入性的，与取样错误有关，并可能导致出血等并发症。因此，开发用于评估肝纤维化的无创成像技术具有临床价值。超声已成为慢性肝病管理的一线工具。然而，常用的 B 型超声是定性的，可能会导致观察者间或观察者内的差异。超声反向散射包络统计参数成像是一组重要的定量超声技术，已应用于表征不同种类的组织。然而，尚未对用于肝纤维化表征的超声反向散射包络统计参数成像进行最先进的审查。在本文中，我们重点介绍了 1998 年至 2019 年 9 月评估肝纤维化的超声反向散射包络统计参数成像技术的发展。我们将这些技术分为六类：恒定误报率、纤维结构提取技术、声学结构量化、分位数–分位数概率图、多瑞利模型和 Nakagami 模型。我们介绍了通过超声反向散射包络统计参数成像评估肝纤维化的理论背景和算法。然后，回顾和分析了超声反向散射包络统计参数成像技术在肝纤维化评估中的具体应用。最后，讨论了每种技术的优缺点，并对未来的发展提出了建议。