Shear Wave Reciprocity for Breast Imaging

摘要： 我们提出了一种新的超声成像方法，称为剪切波互易成像(Sri)。 根据组织的声速和衰减生成图像。这些声学特性承载着 重要的诊断信息，但在传统的B超图像中，除了伪影外，不会显示出来。为 例如，在乳房成像中，BIRADS描述符所依赖的后部特征(阴影/增强) 这些属性。与产生变化的散斑图像的传统B模式成像不同 组织声阻抗，我们建议SRI作为一种衰减/声音的无斑点成像方法 速度参数。SRI图像是对B型和弹性成像图像的补充 使用与常规超声相同的背向散射成像几何结构。SRI依赖于 机械互易性，用于测量声辐射力的局部变化，它与衰减和 声速。虽然使用类似于ARFI成像的声辐射力脉冲，但SRI被设计为 对弹性属性不敏感，并具体成像衰减/声速参数。的目标是 本项目是在线阵成像系统上实现SRI，测试其灵敏度和分辨率 通过活组织检查前的活体测量，验证乳房切除的体外乳腺组织中的SRI。我们 预计SRI提供的额外信息最终将改善病变分类并减少 替换B超对病变衰减的定性估计所需的活检次数 利用参数声学图像进行阴影处理。

Abstract: We propose a new ultrasound image formation method, which we call shear-wave reciprocity imaging (SRI), to produce images based on the sound speed and attenuation of tissue. These acoustic properties carry important diagnostic information but are not revealed in conventional B-mode images except as artifacts. For example, in breast imaging the “posterior features” (shadowing/enhancement) BiRADS descriptor depends on these properties. In contrast to conventional B-mode imaging that produces speckle images of variations in tissue acoustic impedance, we propose SRI as a method for speckle-free imaging of an attenuation/sound speed parameter. SRI images are complementary to both B-mode and elastography images yet are produced using the same backscatter imaging geometry as conventional ultrasound. SRI relies on the principle of mechanical reciprocity to measure local variations in acoustic radiation force, which relate to attenuation and sound speed. While using acoustic radiation force impulses similar to ARFI imaging, SRI is designed to be insensitive to elastic properties and to specifically image the attenuation/sound speed parameter. The aims of this project are to implement SRI on a linear-array imaging system, characterize its sensitivity and resolution through in vivo measurements prior to biopsy, and validate SRI in ex vivo breast tissue from mastectomy. We expect that the additional information provided by SRI will ultimately improve lesion categorization and reduce the number of biopsies required by replacing qualitative estimates of lesion attenuation from B-mode shadowing with parametric acoustic images.