High-speed panoramic 3D photoacoustic computed tomography of the breast

摘要（最多30行） 目的：研制两种新型高速三维乳腺光声计算机断层扫描仪（PACT） 系统诊断良性，非典型和恶性病变-导致更精简和准确的 减少不必要的后续成像和良性乳腺活检。 临床意义：筛查性乳腺X线摄影检测到的异常结果导致检查，包括 额外的成像，通常以额外的乳房X线照片视图、断层合成和/或超声的形式，以及 乳腺活检的可能性。活检有相当大的副作用，如疼痛和出血， 在大多数情况下（60 - 70%）是不必要的，因为乳房X线摄影的假阳性率很高。的 副作用、成本和检查的延迟给患者造成相当大的压力。PACT结合了 漫射光学断层成像的功能性光学对比度和超声的高空间分辨率 没有斑点伪影。近红外光在乳腺组织中的衰减系数仅为 乳房X射线-使足够的光学渗透，但光有更高的软组织对比度比 x光片在高空间和时间分辨率下具有丰富的功能对比度，并且不使用电离辐射 或外源性造影剂，3D乳腺PACT有可能减少不必要的良性乳腺癌 作为乳腺X线摄影的辅助诊断工具。可能的长期乳腺成像 应用不仅包括诊断，而且还包括筛查、对术前系统性免疫应答的评估， 治疗和明确的手术计划。 挑战：需要大量创新来开发有效用于临床的PACT成像系统 乳房成像以前的PACT乳腺成像仪具有明显的局限性，包括次优的光线 递送、有限的检测视图、非各向同性空间分辨率和长扫描时间。仍存在 迫切需要更先进的PACT乳腺成像技术。 解决方案：我们的新技术获得了初步的深度和清晰的体内乳腺图像， 在开发PACT系统后，我们提出了3D功能性乳房成像的进一步创新，以克服 上述限制。目的1：研制一种单次屏气三维乳腺成像系统， 各向同性3D分辨率和双波长对比度（模型I）。目的2：开发快照3D乳房 PACT系统（模型II）使用声学遍历的概念。它可以达到极致的成像速度 （单次激光发射），对于没有运动伪影的3D高分辨率功能和动态成像是理想的。 两种系统均可进行弹性成像。要成像的对比度包括血管分布、浓度和氧气 血红蛋白饱和度、弹性以及肿瘤体积和形状。目的3：测试PACT用于诊断 良性、非典型和恶性乳腺病变，并与组织病理学金标准进行比较。

ABSTRACT (30 Lines Max) Objective: Develop two innovative high-speed 3D breast photoacoustic computed tomography (PACT) systems to diagnose benign, atypical, and malignant lesions — leading to a more streamlined and accurate workup that reduces unnecessary follow-up imaging and benign breast biopsies. Clinical significance: Abnormal findings detected by screening mammography lead to workups including additional imaging, usually in the form of extra mammogram views, tomosynthesis, and/or ultrasound, and possibility of breast biopsy. Biopsies have considerable side effects such as pain and bleeding, and are unnecessary in the majority (60 – 70%) of cases because of the high false-positive rate of mammography. The side effects, costs, and delays of the workups cause considerable stress to patients. PACT combines the functional optical contrast of diffuse optical tomography and the high spatial resolution of ultrasonography without speckle artifacts. The attenuation coefficient of near-IR light in breast tissue is only twice that of mammographic x-ray—enabling adequate optical penetration, but light has far higher soft-tissue contrast than x-ray. With rich functional contrast at high spatial and temporal resolutions and without using ionizing radiation or exogenous contrast agents, 3D breast PACT has the potential to reduce unnecessary benign breast biopsies by serving as a diagnostic tool adjunct to mammography. Possible long-term breast imaging applications include not only diagnosis, but also screening, assessment of response to pre-operative systemic therapy, and definitive surgical planning. Challenges: Numerous innovations are required to develop a PACT imaging system effective for clinical breast imaging. Previous PACT breast imagers possess significant limitations, including suboptimal light delivery, limited detection view, non-isotropic spatial resolution, and long scanning times. There remains an imperative need for more advanced PACT breast imaging technologies. Solutions: Encouraged by the preliminary deep and clear in vivo breast images acquired by our newly developed PACT system, we propose further innovations for 3D functional breast imaging to overcome the above-mentioned limitations. Aim 1: To develop a single-breath-hold 3D breast imaging system with nearly isotropic 3D resolutions and dual-wavelength contrasts (Model I). Aim 2: To develop a snapshot 3D breast PACT system (Model II) using the concept of acoustic ergodicity. It can reach the ultimate imaging speed (single laser shot), desirable for 3D high-resolution functional and dynamic imaging without motion artifacts. Both systems can perform elastography. Contrasts to be imaged include vascularity, concentration and oxygen saturation of hemoglobin, elasticity, and tumor volume and shape. Aim 3: To test PACT for the diagnosis of benign, atypical, and malignant breast lesions by comparing with the gold standard of tissue pathology.