Dehghani Hamid, Pogue Brian W, Shudong Jiang, Brooksby Ben, Paulsen Keith D
Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755, USA.
Appl Opt. 2003 Jun 1;42(16):3117-28. doi: 10.1364/ao.42.003117.
Near-infrared (NIR) optical tomography provide estimates of the internal distribution of optical absorption and transport scattering from boundary measurement of light propagation within biological tissue. Although this is a truly three-dimensional (3D) imaging problem, most research to date has concentrated on two-dimensional modeling and image reconstruction. More recently, 3D imaging algorithms are demonstrating better estimation of the light propagation within the imaging region and are providing the basis of more accurate image construction algorithms. As 3D methods emerge, it will become increasingly important to evaluate their resolution, contrast, and localization of optical property heterogeneity. We present a concise study of 3D reconstructed resolution of a small, low-contrast, absorbing and scattering anomaly as it is placed in different locations within a cylindrical phantom. The object is an 8-mm-diameter cylinder, which represents a typical small target that needs to be resolved in NIR mammographic imaging. The best resolution and contrast is observed when the object is located near the periphery of the imaging region (12-22 mm from the edge) and is also positioned within the multiple measurement planes, with the most accurate results seen for the scatter image when the anomaly is at 17 mm from the edge. Furthermore, the accuracy of quantitative imaging is increased to almost 100% of the target values when a priori information regarding the internal structure of imaging domain is utilized.
近红外（NIR）光学断层扫描通过对生物组织内光传播的边界测量来估计光吸收和传输散射的内部分布。尽管这是一个真正的三维（3D）成像问题，但迄今为止大多数研究都集中在二维建模和图像重建上。最近，3D成像算法在对成像区域内的光传播估计方面表现得更好，并为更精确的图像构建算法提供了基础。随着3D方法的出现，评估其分辨率、对比度以及光学特性异质性的定位将变得越来越重要。我们对一个小的、低对比度的吸收和散射异常体在圆柱形体模内不同位置放置时的3D重建分辨率进行了简要研究。该物体是一个直径8毫米的圆柱体，代表了近红外乳腺成像中需要分辨的典型小目标。当物体位于成像区域周边附近（距离边缘12 - 22毫米）且处于多个测量平面内时，观察到最佳分辨率和对比度，当异常体距离边缘17毫米时，散射图像的结果最为准确。此外，当利用关于成像域内部结构的先验信息时，定量成像的准确性提高到几乎目标值的100%。
