A Computational Framework Enabling Virtual Imaging Trials of 3D Quantitative Optoacoustic Tomography Breast Imaging

摘要 光声断层成像（OAT），也称为光声计算机断层成像，是一种非侵入性的成像技术。 正在积极开发用于乳腺癌成像和其他生物医学应用的成像模式。一 OAT的一个独特功能是能够根据与之相关的内源性光学对比度生成图像 与组织内血红蛋白的浓度和氧合状态，没有电离辐射， 空间分辨率的损失通常与纯光学技术（例如光学漫射）相关联 断层扫描因为侵袭性生长的恶性乳腺肿瘤往往处于缺氧状态并减少 由于与健康组织相比代谢活动显著增加， 经过优化和验证的OAT系统可以成为一种强大的工具，用于乳腺癌的管理， 肿瘤微血管密度及其血液氧合。 目前，还没有经过验证的OAT方法能够足够准确地用于广泛的临床成像， 乳房;重要问题，如最佳硬件和图像重建设计，解决 深部病变和定量成像仍未解决。由于光的竞争要求， 为了提供和声学检测，已经提出了用于乳房OAT的各种不同的系统设计;这 与X射线乳房X光摄影、乳房MRI和乳房超声不同，在这些领域中， 按模态使用。考虑到所涉及的大量参数， 由于时间和成本限制以及伦理问题，通过人体试验优化乳腺OAT。然而，在这方面， 虚拟成像试验（VITs），其中通过使用代表性数值 幻影和成像模型，可以提供一个快速和具有成本效益的手段，评估和优化新的 成像概念和技术，如OAT。目前缺乏对3D OAT进行VITs的能力。 该项目的主要目标是开发、验证和演示计算工具， 执行VITs，可以为临床上可行和有效的3D乳腺OAT技术的开发提供信息。 这将为研究人员在建模和验证定量OAT方面提供前所未有的控制水平 评估乳腺癌所需的肿瘤和组织氧饱和度分布的成像。的 结果将是第一次评估OAT基于任务的优点和能力， 在这些研究中可达到的目标对于将这项技术转化为临床至关重要。 该项目的具体目标是：目标1。开发多物理场模拟工具， 在3D乳房OAT中模拟真实测量数据; Aim 2.系统地发展和完善 定量OAT图像重建方法;目的3.进行物理实验， 验证计算模型;目标4.进行虚拟测试，以探索量化的OAT系统优化。

ABSTRACT Optoacoustic tomography (OAT), also known as photoacoustic computed tomography, is a non-invasive imaging modality actively being developed for breast cancer imaging and other biomedical applications. A unique feature of OAT is the ability to produce an image based on the endogenous optical contrast associated with the concentration and oxygenation state of hemoglobin within tissue, without ionizing radiation and without the loss of spatial resolution typically associated with purely optical techniques such as optical diffusion tomography. Because aggressively growing malignant breast tumors tend to be under hypoxia and decreased blood oxygen saturation due to substantially increased metabolic activity in comparison to healthy tissue, an optimized and validated OAT system can be a powerful tool for the management of breast cancer by assessing density of the tumor microvasculature and its blood oxygenation. Currently, there is no validated OAT method that is sufficiently accurate for widespread clinical imaging of the breast; important issues such as optimal hardware and image reconstruction designs, the ability to resolve lesions at depth, and quantitative imaging remain unresolved. Due to the competing requirements of light delivery and acoustic detection, a variety of different system designs for breast OAT have been proposed; this is unlike in x-ray mammography, breast MRI and breast ultrasound, where very similar implementations are in use per modality. Considering the large number of parameters involved, it is infeasible to systematically optimize breast OAT through human trials due to time- and cost-constraints and ethical concerns. However, virtual imaging trials (VITs), where an imaging study is conducted in silico by use of representative numerical phantoms and imaging models, can offer a rapid and cost-efficient means of assessing and optimizing new imaging concepts and technologies such as OAT. The ability to conduct VITs for 3D OAT is currently lacking. The broad objective of this project is to develop, validate, and demonstrate computational tools for performing VITs that can inform the development of clinically viable and effective 3D breast OAT technologies. This will afford researchers an unprecedented level of control in modeling and validating quantitative OAT imaging of the tumor and tissue oxygen saturation distributions necessary for assessing breast cancer. The results will be the first of their kind evaluating the task-based merits and capabilities of OAT and the knowledge attainable in these studies is critical for translating this technology to the clinic. The Specific Aims of the project are: Aim 1. To develop multi-physics simulation tools for the in silico simulation of realistic measurement data in 3D breast OAT; Aim 2. To systematically develop and refine quantitative OAT image reconstruction methods; Aim 3. To conduct physical experiments that will be used to validate the computational models; Aim 4. To conduct VITs to explore quantitative OAT system optimization.