Investigation of Moiré Pattern-based Phase Retrieval Approach for Differential Phase-contrast Cone Beam CT Imaging Using a Hospital-grade Tube.
Investigation of Moiré Pattern-based Phase Retrieval Approach for Differential Phase-contrast Cone Beam CT Imaging Using a Hospital-grade Tube.
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DOI：
10.1117/12.911342
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Conover D
中科院分区：
文献类型：
--
作者：
Cai W;Ning R;Yu Y;Liu J;Conover D
相位步进算法是基于光栅的差相对比成像（DPC）中常用的相位恢复算法，该算法需要多个强度图像来计算一个DPC图像。数据采集效率不高，特别是在使用DPC成像或基于DPC的来束CT （DPC- cbct）成像进行动态成像的情况下。一种基于傅立叶变换的方法已经被开发用于光学条纹图分析，并且最近被应用到基于同步加速器的DPC层析成像系统中。在本研究中，将该方法进一步发展为带有医院级x射线管的台式DPC-CBCT成像系统。其关键思想是在干涉图的傅里叶域中分离载波条纹和目标信息，并利用目标信息重建差分相位信息。相位恢复只需要一个干涉图，代价是空间分辨率。该方法采用波纹条纹作为载波条纹，并通过扫描图像来评价该方法。研究了不同载波条纹频率的干涉图，并从对比度、噪声和清晰度等方面评价了重建图像的质量。结果表明，基于傅里叶变换的方法可以有效地恢复DPC图像，重建的相位系数比基于衰减的对比度具有更好的对比度。空间分辨率在模拟研究中是可以接受的，但不如步进法的结果好。基于傅里叶变换的相位恢复方法能够大大简化数据采集，提高时间分辨率，使动态DPC-CBCT成像成为可能。它是有希望的灌注成像，空间分辨率不是一个问题。
The phase stepping algorithm is commonly used for phase retrieval in grating-based differential phase-contrast (DPC) imaging, which requires multiple intensity images to compute one DPC image. It is not efficient for data acquisition, especially in the case of dynamic imaging using either DPC imaging or DPC-based come beam CT (DPC-CBCT) imaging. A Fourier transform-based approach has been developed for fringe pattern analysis in optics, and it was recently implemented into a synchrotron-based DPC tomography system. In this research, this approach is further developed for a bench-top DPC-CBCT imaging system with a hospital-grade x-ray tube. The key idea is to separate carrier fringes and object information in Fourier domain of the interferogram and to reconstruct the differentiated phase information using the object information. Only one interferogram is required for phase retrieval at a cost of spatial resolution. The fringes of moiré patterns are used as the carrier fringes, and a phantom is scanned to evaluate the approach. Various interferograms with different carrier fringe frequencies are investigated and the reconstruction image quality is evaluated in terms of contrast, noise and sharpness. The results indicated that the DPC images can be effectively retrieved using the Fourier transform-based approach and the reconstructed phase coefficient showed better contrast compared to that of attenuation-based contrast. The spatial resolution is acceptable in the phantom studies although it is not as good as the results of phase-stepping approach. The Fourier transform-based phase retrieval approach is able to greatly simplify data acquisition, to improve the temporal resolution and to make it possible for dynamic DPC-CBCT imaging. It is promising for perfusion imaging where spatial resolution is not a concern.
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影响因子：
19.6
作者：
Pfeiffer, F;Weitkamp, T;David, C
通讯作者：
David, C
DOI：
10.1117/12.878492
发表时间：
2011-03-16
期刊：
Proceedings of SPIE--the International Society for Optical Engineering
影响因子：
--
作者：
Yu Y;Ning R;Cai W
通讯作者：
Cai W
影响因子：
--
作者：
TAKEDA, M;INA, H;KOBAYASHI, S
通讯作者：
KOBAYASHI, S
影响因子：
3.8
作者：
Momose, Atsushi;Yashiro, Wataru;Takeda, Yoshihiro
通讯作者：
Takeda, Yoshihiro
DOI：
10.1143/jjap.42.l866
发表时间：
2003-07-15
期刊：
JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS
影响因子：
--
作者：
Momose, A;Kawamoto, S;Suzuki, Y
通讯作者：
Suzuki, Y