IEEE Trans Ultrason Ferroelectr Freq Control. 2021 Jul;68(7):2602-2605. doi: 10.1109/TUFFC.2021.3066796. Epub 2021 Jun 29.
The modeling of source a distributions of finite spatial extent in ultrasound and medical imaging applications is a problem of longstanding interest. In time-domain methods, such as the finite-difference time-domain or pseudospectral approaches, one requirement is the representation of such distributions over a grid, normally Cartesian. Various artifacts, including staircasing errors, can arise. In this short contribution, the problem of the representation of distribution over a grid is framed as an optimization problem in the Fourier domain over a preselected set of grid points, thus maintaining control over computational cost and allowing the fine-tuning of the optimization to the wavenumber range of interest for a particular numerical method. Numerical results are presented in the important special case of the spherical cap or bowl source.
在超声学和医学成像应用中，对有限空间范围源分布的建模是一个由来已久的问题。在时域方法中，如有限差分时域或伪谱方法，一个要求是在网格上表示这种分布，通常是笛卡尔网格。会出现各种伪影，包括阶梯误差。在这篇简短的文章中，将网格上分布的表示问题作为在预选择的网格点集上的傅里叶域中的优化问题来解决，从而保持对计算成本的控制，并允许根据特定数值方法的感兴趣的波数范围对优化进行微调。在球形帽或碗形源的重要特殊情况下给出了数值结果。
