Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130 USA.
IEEE Trans Med Imaging. 2013 Jun;32(6):1097-110. doi: 10.1109/TMI.2013.2254496. Epub 2013 Mar 22.
Existing approaches to image reconstruction in photoacoustic computed tomography (PACT) with acoustically heterogeneous media are limited to weakly varying media, are computationally burdensome, and/or cannot effectively mitigate the effects of measurement data incompleteness and noise. In this work, we develop and investigate a discrete imaging model for PACT that is based on the exact photoacoustic (PA) wave equation and facilitates the circumvention of these limitations. A key contribution of the work is the establishment of a procedure to implement a matched forward and backprojection operator pair associated with the discrete imaging model, which permits application of a wide-range of modern image reconstruction algorithms that can mitigate the effects of data incompleteness and noise. The forward and backprojection operators are based on the k-space pseudospectral method for computing numerical solutions to the PA wave equation in the time domain. The developed reconstruction methodology is investigated by use of both computer-simulated and experimental PACT measurement data.
现有的针对声介质不均匀的光声计算机断层成像（PACT）的图像重建方法仅限于介质的弱变化，计算负担重，并且/或者不能有效地减轻测量数据不完整和噪声的影响。在这项工作中，我们开发并研究了一种基于精确光声（PA）波动方程的 PACT 离散成像模型，该模型有助于克服这些限制。这项工作的一个主要贡献是建立了一种实现与离散成像模型相关的匹配正向和反向投影算子对的程序，该程序允许应用广泛的可以减轻数据不完整和噪声影响的现代图像重建算法。正向和反向投影算子基于 k 空间伪谱法，用于在时域中计算 PA 波动方程的数值解。所开发的重建方法通过使用计算机模拟和实验 PACT 测量数据进行了研究。
