Ultrasound phantom-free regularized local attenuation imaging

临床超声成像为诊断和治疗随访提供了不同的成像模式。灰度B模式成像提供解剖信息，多普勒模式用于测量血流和组织运动，弹性成像模式可评估组织的机械特性。最近，主要的超声放射学制造商开始发布用于组织表征和成像的声速、衰减和反向散射包。这些成像模式进入被称为“定量超声”（QUS）成像的类别，其目的是基于组织与传播的超声波的相互作用来提供组织的基本物理性质的签名。本申请旨在进一步开发这些QUS成像方法之一，即已知随病理变化的局部衰减的量化。QUS成像的领域特别旨在提供声散射体或细胞的亚分辨率特性，以用于生物组织表征的目的。这些方法中的一些的一个缺点是需要校准体模测量来补偿扫描器和波与声穿透组织的相互作用特性的混杂效应。在这个建议中，提出了一种无幻像正则化局部衰减测量方法，用于肝脏疾病的诊断成像。该方法的理论框架依赖于在传输的压缩波的带宽内的不同频率处的类似波衍射效应的假设。所提出的成像方法的验证将依赖于计算机模拟、体外凝胶体模实验和临床射频图像的处理。将通过考虑背景噪声、同质或异质组织、衰减对比以及是否存在具有不同组织特征的夹杂物（肿瘤）等各种条件来评估耐用性。地面实况测量将可用于与拟议的成像方法进行比较。技术创新将与我们的工业合作伙伴西门子医疗的产品开发优先事项保持一致。

Clinical ultrasound imaging provides different imaging modes for the purpose of diagnosis and therapy follow-up. Gray-scale B-mode imaging gives anatomy information, Doppler modes are used for measuring flow and tissue motion, and elastography modes allow assessing the mechanical property of tissues. Very recently, major ultrasound radiology manufacturers started releasing speed of sound, attenuation, and backscatter packages for tissue characterization and imaging. Those imaging modes enter into the category known as "quantitative ultrasound" (QUS) imaging, which aims providing a signature of a fundamental physical property of a tissue based on its interaction with propagating ultrasound waves. This application aims to further develop one of these QUS imaging methods, namely the quantification of the local attenuation known to change with pathology. The field of QUS imaging specifically aims to provide sub-resolution characteristics of acoustic scatterers or cells for the purpose of biological tissue characterization. One drawback of some of these methods is the requirement of a calibration phantom measurement to compensate for confounding effects of scanner and wave interaction characteristics with the insonified tissue. In this proposal, a phantom-free regularized local attenuation measurement method is proposed for applications in diagnostic imaging of liver diseases. The theoretical framework of the method relies on the assumption of similar wave diffraction effects at different frequencies within the bandwidth of the transmitted compression wave. Validation of the proposed imaging method will rely on computer simulations, in vitro gel phantom experiments and processing of clinical radiofrequency images. Robustness will be assessed by considering various conditions of background noise, homogeneous or heterogeneous tissues, attenuation contrasts, and presence or not of an inclusion (tumor) with different tissue characteristics. Ground truth measurements will be available for comparison with the proposed imaging method. Technological innovations will be made in line with product development priorities of our industrial partner, Siemens Healthcare.