Resolution improvement in emission optical projection tomography
Resolution improvement in emission optical projection tomography
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DOI：
10.1088/0031-9155/52/10/010
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发表时间：
2007-05-21
影响因子：
3.5
通讯作者：
Henkelman, R. Mark
中科院分区：
文献类型：
--
作者：
Walls, Johnathon R.;Sled, John G.;Henkelman, R. Mark
一种称为发射光学投影断层扫描（eOPT）的新成像技术，本质上是单光子发射计算机断层扫描（SPECT）的光学版本，提供分子特异性，微米至数十微米量级的分辨率和大样本覆盖范围（约1立方厘米）。它非常适合胚胎中的基因表达研究。重建的eOPT图像遭受随着距旋转轴的距离增加而模糊的问题。这种模糊部分是由透镜的点扩散函数的散焦引起的，该散焦函数随着离焦平面的物体距离而增加。在本文中，我们描述了一种基于正弦图的频率-距离关系的频率空间滤波器，用于对距离相关的点扩散函数进行去卷积，并在重建之前从eOPT正弦图中排除高度散焦的数据。所示的方法，以减少在半最大值的重建点扩散函数的体积约20%的原始，和体积在10%的最大值约6%的原始。作为说明，9.5天大的小鼠胚胎的脉管系统中的精细细节的可见性显著提高。
A new imaging technique called emission optical projection tomography (eOPT), essentially an optical version of single-photon emission computed tomography (SPECT), provides molecular specificity, resolution on the order of microns to tens of microns, and large specimen coverage (approximate to 1 cubic centimetre). It is ideally suited to gene expression studies in embryos. Reconstructed eOPT images suffer from blurring that worsens as the distance from the axis of rotation increases. This blur is caused in part by the defocusing of the lens' point-spread function, which increases with object distance from the focal plane. In this paper, we describe a frequency space filter based on the frequency-distance relationship of sinograms to deconvolve the distance-dependent point-spread function and exclude highly defocused data from the eOPT sinograms prior to reconstruction. The method is shown to reduce the volume at half-maximum of the reconstructed point-spread function to approximately 20% the original, and the volume at 10% maximum to approximately 6% the original. As an illustration, the visibility of fine details in the vasculature of a 9.5 day old mouse embryo is dramatically improved.