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

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 计算任意分布的悬浮在水平方向的矩形体模中的球体的声散射。这是通过多中心T-矩阵方法实现的，其中球面展开和角谱展开分别用于表示球面和体模表面的散射场。为了满足各种边界条件，计算了变换矩阵，以将球面展开与角谱展开联系起来，将角谱展开与球面展开联系起来，并将球面展开与平移球面展开联系起来。给出了几个典型算例的计算结果。

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.