Jiang H, Paulsen K D, Osterberg U L, Patterson M S
Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
Phys Med Biol. 1998 Mar;43(3):675-93. doi: 10.1088/0031-9155/43/3/018.
The image reconstruction enhancement schemes of total variation minimization, dual meshing and iterative spatial filtering have been applied to laboratory data collected from continuous light illumination of tissue-like phantoms. Experiments include both single- and multi-target cases where variations in object size (4 mm to 20 mm), position (centred to near boundary) and contrast with the background (2:1 to 8:1) have been explored. The results show that dramatic improvements in image quality have been obtained in terms of geometric and spatial resolution measures relative to those previously reported for continuous light, but quantitative information on the actual optical properties of embedded heterogeneities is still lacking. Specifically, the geometric characteristics of object size, position and shape are generally accurate to 10-20% and the spatial resolution metrics of background-to-object size and neighbouring-edge separation are approximately 10:1. Direct comparisons are also made with images obtained with intensity-modulated light under identical experimental conditions. Images from intensity-modulated light are found to be superior to continuous light in several important ways, most notably in terms of the ability to quantitatively discriminate the optical property values of embedded targets from the surrounding background. Continuous-light images are also found to have centrally located artefacts in many instances which do not appear in the corresponding intensity-modulated cases.
总变差最小化、对偶网格划分和迭代空间滤波等图像重建增强方案已应用于从类组织体模的连续光照中收集的实验室数据。实验包括单目标和多目标情况，其中研究了物体尺寸（4毫米至20毫米）、位置（中心到近边界）以及与背景的对比度（2:1至8:1）的变化。结果表明，相对于先前报道的连续光图像，在几何和空间分辨率测量方面，图像质量有了显著提高，但仍缺乏关于嵌入异质性实际光学特性的定量信息。具体而言，物体尺寸、位置和形状的几何特征通常精确到10%-20%，背景与物体尺寸以及相邻边缘间距的空间分辨率指标约为10:1。还在相同实验条件下与强度调制光获得的图像进行了直接比较。发现强度调制光的图像在几个重要方面优于连续光图像，最显著的是在从周围背景中定量区分嵌入目标的光学特性值的能力方面。还发现连续光图像在许多情况下存在位于中心的伪影，而在相应的强度调制情况下则不存在。
