Baikejiang Reheman, Zhang Wei, Li Changqing
J Xray Sci Technol. 2017;25(3):341-355. doi: 10.3233/XST-16183.
Diffuse optical tomography (DOT) has attracted attentions in the last two decades due to its intrinsic sensitivity in imaging chromophores of tissues such as hemoglobin, water, and lipid. However, DOT has not been clinically accepted yet due to its low spatial resolution caused by strong optical scattering in tissues. Structural guidance provided by an anatomical imaging modality enhances the DOT imaging substantially. Here, we propose a computed tomography (CT) guided multispectral DOT imaging system for breast cancer imaging. To validate its feasibility, we have built a prototype DOT imaging system which consists of a laser at the wavelength of 650 nm and an electron multiplying charge coupled device (EMCCD) camera. We have validated the CT guided DOT reconstruction algorithms with numerical simulations and phantom experiments, in which different imaging setup parameters, such as projection number of measurements and width of measurement patch, have been investigated. Our results indicate that an air-cooling EMCCD camera is good enough for the transmission mode DOT imaging. We have also found that measurements at six angular projections are sufficient for DOT to reconstruct the optical targets with 2 and 4 times absorption contrast when the CT guidance is applied. Finally, we have described our future research plan on integration of a multispectral DOT imaging system into a breast CT scanner.
在过去二十年中，扩散光学层析成像（DOT）因其对组织中诸如血红蛋白、水和脂质等发色团成像具有内在敏感性而备受关注。然而，由于组织中强烈的光散射导致其空间分辨率较低，DOT尚未被临床所接受。解剖成像模态提供的结构引导可显著增强DOT成像效果。在此，我们提出一种用于乳腺癌成像的计算机断层扫描（CT）引导多光谱DOT成像系统。为验证其可行性，我们构建了一个原型DOT成像系统，该系统由一台波长为650纳米的激光器和一台电子倍增电荷耦合器件（EMCCD）相机组成。我们通过数值模拟和体模实验验证了CT引导的DOT重建算法，其中研究了不同的成像设置参数，如测量投影数和测量斑块宽度。我们的结果表明风冷EMCCD相机足以用于透射模式DOT成像。我们还发现，当应用CT引导时，六个角度投影的测量对于DOT重建具有2倍和4倍吸收对比度的光学目标就足够了。最后，我们描述了将多光谱DOT成像系统集成到乳腺CT扫描仪中的未来研究计划。
