Assessment of scatter components in high-resolution PET: correction by nonstationary convolution subtraction.
Assessment of scatter components in high-resolution PET: correction by nonstationary convolution subtraction.
复制标题
高分辨率 PET 中散射成分的评估：通过非平稳卷积减法进行校正。
DOI：
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发表时间：
1995
影响因子：
9.3
通讯作者：
R. Lecomte
中科院分区：
文献类型：
--
作者：
M. Bentourkia;P. Msaki;J. Cadorette;R. Lecomte
未标记
本文介绍了一种新的方法，以确定个人的散射核，并使用它们的散射校正的积分变换的投影。
方法
单个散射分量拟合线源的投影单指数。然后，每个散射分量的位置相关散射参数用于为投影中的每个点设计非稳态散射校正内核。这些内核中使用的卷积减法，连续删除对象，准直器和检测器的散射投影。该方法基于一个模型，该模型假设图像退化完全来自湮灭光子的康普顿相互作用，从而忽略了物体散射与准直器和检测器的进一步康普顿相互作用。
结果
对象散射分量的减法改进了用标准卷积减法获得的典型对比度。准直器散射分量很弱，因此可以安全地与目标散射组合进行校正。从图像中减去探测器散射并没有提高对比度，因为从热区域中删除计数而冷区域（背景）保持不变会降低统计准确性。
结论
减去对象和准直器散射仅改善对比度。减去探测器散射导致的图像清晰度的轻微增益并不证明以牺牲灵敏度为代价去除该分量是合理的。
UNLABELLED
This paper describes a new approach to determine individual scatter kernels and to use them for scatter correction by integral transformation of the projections.
METHODS
Individual scatter components are fitted on the projections of a line source by monoexponentials. The position-dependent scatter parameters of each scatter components are then used to design non-stationary scatter correction kernels for each point in the projection. These kernels are used in a convolution-subtraction method which consecutively removes object, collimator and detector scatter from projections. This method is based on a model which assumes that image degradation results exclusively from Compton interactions of annihilation photons, thus neglecting further Compton interactions of object scatters with collimator and detector.
RESULTS
Subtraction of the object scatter component improved contrast typical of what is obtained with standard convolution-subtraction methods. The collimator scatter component is so weak that it can be safely combined with object scatter for correction. Subtraction of detector scatter from images did not improve contrast because statistical accuracy is degraded by removing counts from hot regions while cold regions (background) remain unchanged.
CONCLUSION
Subtraction of object and collimator scatter improves contrast only. The slight gain in image sharpness resulting from the subtraction of detector scatter does not justify removal of this component at the expense of sensitivity.