Thayer School of Engineering, Dartmouth College, 14 Engineering Dr., Hanover, NH 03755, United States of America.
Phys Med Biol. 2017 Nov 10;62(23):8983-9000. doi: 10.1088/1361-6560/aa94b6.
A multimodal micro-computed tomography (CT) and multi-spectral structured light imaging (SLI) system is introduced and systematically analyzed to test its feasibility to aid in margin delineation during breast conserving surgery (BCS). Phantom analysis of the micro-CT yielded a signal-to-noise ratio of 34, a contrast of 1.64, and a minimum detectable resolution of 240 μm for a 1.2 min scan. The SLI system, spanning wavelengths 490 nm to 800 nm and spatial frequencies up to 1.37 [Formula: see text], was evaluated with aqueous tissue simulating phantoms having variations in particle size distribution, scatter density, and blood volume fraction. The reduced scattering coefficient, [Formula: see text] and phase function parameter, γ, were accurately recovered over all wavelengths independent of blood volume fractions from 0% to 4%, assuming a flat sample geometry perpendicular to the imaging plane. The resolution of the optical system was tested with a step phantom, from which the modulation transfer function was calculated yielding a maximum resolution of 3.78 cycles per mm. The three dimensional spatial co-registration between the CT and optical imaging space was tested and shown to be accurate within 0.7 mm. A freshly resected breast specimen, with lobular carcinoma, fibrocystic disease, and adipose, was imaged with the system. The micro-CT provided visualization of the tumor mass and its spiculations, and SLI yielded superficial quantification of light scattering parameters for the malignant and benign tissue types. These results appear to be the first demonstration of SLI combined with standard medical tomography for imaging excised tumor specimens. While further investigations are needed to determine and test the spectral, spatial, and CT features required to classify tissue, this study demonstrates the ability of multimodal CT/SLI to quantify, visualize, and spatially navigate breast tumor specimens, which could potentially aid in the assessment of tumor margin status during BCS.
介绍并系统分析了一种多模态微计算机断层扫描（CT）和多光谱结构光成像（SLI）系统，以测试其在乳腺癌保乳手术（BCS）中辅助边缘勾画的可行性。微 CT 的体模分析得到了 34 的信噪比、1.64 的对比度和 240μm 的最小可检测分辨率，扫描时间为 1.2 分钟。SLI 系统的波长范围为 490nm 至 800nm，空间频率高达 1.37 [Formula: see text]，用具有不同粒径分布、散射密度和血容量分数的水基组织模拟体模进行了评估。在假设样品垂直于成像平面的平面几何形状下，在 0%至 4%的所有血容量分数范围内，准确地恢复了 [Formula: see text]和相位函数参数 γ 的低散射系数，而与血容量分数无关。使用阶跃体模测试了光学系统的分辨率，从中计算出调制传递函数，得出最大分辨率为 3.78 周期/mm。测试了 CT 和光学成像空间之间的三维空间配准，结果表明精度在 0.7mm 以内。对一个带有小叶癌、纤维囊性疾病和脂肪的新鲜切除乳房标本进行了成像。微 CT 显示了肿瘤肿块及其刺突的可视化，SLI 对恶性和良性组织类型的光散射参数进行了表面量化。这些结果似乎是首次将 SLI 与标准医学断层扫描相结合，用于成像切除的肿瘤标本。虽然需要进一步研究以确定和测试用于分类组织的光谱、空间和 CT 特征，但本研究证明了多模态 CT/SLI 定量、可视化和空间导航乳房肿瘤标本的能力，这可能有助于评估 BCS 中的肿瘤边缘状态。
