Cloutier Guy, Destrempes François, Yu François, Tang An
Laboratory of Biorheology and Medical Ultrasonics, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), 900 St-Denis, Montréal, Québec, H2X 0A9, Canada.
Department of Radiology, Radio-oncology, and Nuclear Medicine, Université de Montréal, Montréal, Québec, Canada.
Insights Imaging. 2021 Sep 9;12(1):127. doi: 10.1186/s13244-021-01071-w.
Quantitative ultrasound (QUS) aims at quantifying interactions between ultrasound and biological tissues. QUS techniques extract fundamental physical properties of tissues based on interactions between ultrasound waves and tissue microstructure. These techniques provide quantitative information on sub-resolution properties that are not visible on grayscale (B-mode) imaging. Quantitative data may be represented either as a global measurement or as parametric maps overlaid on B-mode images. Recently, major ultrasound manufacturers have released speed of sound, attenuation, and backscatter packages for tissue characterization and imaging. Established and emerging clinical applications are currently limited and include liver fibrosis staging, liver steatosis grading, and breast cancer characterization. On the other hand, most biological tissues have been studied using experimental QUS methods, and quantitative datasets are available in the literature. This educational review addresses the general topic of biological soft tissue characterization using QUS, with a focus on disseminating technical concepts for clinicians and specialized QUS materials for medical physicists. Advanced but simplified technical descriptions are also provided in separate subsections identified as such. To understand QUS methods, this article reviews types of ultrasound waves, basic concepts of ultrasound wave propagation, ultrasound image formation, point spread function, constructive and destructive wave interferences, radiofrequency data processing, and a summary of different imaging modes. For each major QUS technique, topics include: concept, illustrations, clinical examples, pitfalls, and future directions.
定量超声（QUS）旨在量化超声与生物组织之间的相互作用。QUS技术基于超声波与组织微观结构之间的相互作用来提取组织的基本物理特性。这些技术提供了关于在灰度（B模式）成像中不可见的亚分辨率特性的定量信息。定量数据既可以表示为全局测量值，也可以表示为叠加在B模式图像上的参数图。最近，主要的超声设备制造商已经推出了用于组织表征和成像的声速、衰减和背散射软件包。目前，已确立和新兴的临床应用有限，包括肝纤维化分期、肝脂肪变性分级和乳腺癌表征。另一方面，大多数生物组织已通过实验性QUS方法进行了研究，文献中也有定量数据集。这篇教育综述探讨了使用QUS进行生物软组织表征的一般主题，重点是向临床医生传播技术概念，并为医学物理学家提供专门的QUS材料。在单独标识的子部分中还提供了先进但简化的技术描述。为了理解QUS方法，本文回顾了超声波的类型、超声波传播的基本概念、超声图像形成、点扩散函数、相长和相消波干涉、射频数据处理以及不同成像模式的总结。对于每种主要的QUS技术，主题包括：概念、图示、临床实例、陷阱和未来方向。
