Abstract:
Recent progress regarding shortwave-infrared (SWIR) molecular imaging technology has inspired another modality of noninvasive diagnosis for early breast cancer detection in which previous mammography or sonography would be compensated. Although a SWIR fluorescence image of a small breast cancer of several millimeters was obtained from experiments with small animals, detailed numerical analyses before clinical application were required, since various parameters such as size as well as body hair differed between humans and small experimental animals. In this study, the feasibility of SWIR was compared against visible (VIS) and near-infrared (NIR) region, using the Monte Carlo simulation in voxelized media. In this model, due to the implementation of the excitation gradient, fluorescence is based on rational mechanisms, whereas fluorescence within breast cancer is spatially proportional to excitation intensity. The fluence map of SWIR simulation with excitation gradient indicated signals near the upper surface of the cancer, and stronger than those of the NIR. Furthermore, there was a dependency on the fluence signal distribution on the contour of the breast tissue, as well as the internal structure, due to the implementation of digital anatomical data for the Visible Human Project. The fluorescence signal was observed to become weaker in all regions including the VIS, the NIR, and the SWIR region, when fluorescence-labeled cancer either became smaller or was embedded in a deeper area. However, fluorescence in SWIR alone from a cancer of 4 mm diameter was judged to be detectable at a depth of 1.4 cm.
摘要:
有关短波红外(SWIR)分子成像技术的最新进展激发了另一种用于早期乳腺癌检测的无创诊断方式,其中可以补偿先前的乳房X线照相术或超声检查。尽管从小动物的实验中获得了几毫米的小乳腺癌的SWIR荧光图像,需要在临床应用之前进行详细的数值分析,因为人类和小型实验动物之间的各种参数,如大小和体毛不同。在这项研究中,将SWIR的可行性与可见光(VIS)和近红外(NIR)区域进行了比较,在体素化介质中使用蒙特卡罗模拟。在这个模型中,由于激励梯度的实施,荧光是基于合理的机制,而乳腺癌内的荧光在空间上与激发强度成正比。具有激发梯度的SWIR模拟的注量图指示癌症上表面附近的信号,比NIR强。此外,对乳房组织轮廓的注量信号分布有依赖性,以及内部结构,由于可见人体项目的数字解剖数据的实施。在包括VIS在内的所有区域观察到荧光信号变弱,NIR,和SWIR区域,当荧光标记的癌症变得更小或嵌入更深的区域时。然而,仅SWIR中的来自4mm直径的癌症的荧光被判断为在1.4cm的深度处可检测到。