ULTRASOUND SCATTERING FROM A DISTRIBUTION OF SPHERES IN A TISSUE-MIMICKING PHAN

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 计算悬浮在水平方向矩形体模内的任意分布球体的声散射。这是通过多中心T矩阵的方法，其中球面展开和角谱展开被用来表示从球体的表面和幻影的表面，分别散射场。为了满足各种边界条件，计算变换矩阵以将球面展开与角谱展开、角谱展开与球面展开以及球面展开与平移球面展开相关联。对几种典型情况进行了数值算例计算。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Compute the acoustic scattering for an arbitrary distribution of spheres suspended within a horizontally oriented rectangular phantom. This is accomplished via the multicentered T-Matrix approach, in which spherical expansions and angular spectrum expansions are used to express the scattered fields from the surfaces of the spheres and the surfaces of the phantom, respectively. In order to satisfy the various boundary conditions, transformation matrices are computed to relate spherical expansions to angular spectrum expansions, angular spectrum expansions to spherical expansions, and spherical expansions to translated spherical expansions. The results of numerical examples are computed for some representative cases.