Multiple-image radiography
Multiple-image radiography
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DOI：
10.1088/0031-9155/48/23/006
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发表时间：
2003-12-07
影响因子：
3.5
通讯作者：
Muehleman, C
中科院分区：
文献类型：
--
作者：
Wernick, MN;Wirjadi, O;Muehleman, C
传统的射线照相术通过测量穿过物体的X射线束的衰减来产生物体的单一图像。当对弱吸收组织成像时，X射线衰减可能是与疾病相关的信息的次佳特征。在本文中，我们描述了一种新的相敏成像方法，称为多像射线成像(MIR)，它是对现有的衍射增强成像(DEI)技术的改进。本文详细阐述了我们在Wernick等人(2002 Proc.内部交响乐。生物医学。成像页129-32)。MIR同时从一组用一束X射线进行的测量中产生几幅图像。具体地说，MIR产生了三幅图像，分别描述了物体的折射、超小角度散射和衰减的影响。这三幅图像的对比度都很好，部分原因是它们几乎不会因为更高角度的散射而退化。MIR还提供了一个非常全面的天体描述，包括在一个狭窄的角度范围内，在每个图像像素上传输的X射线束的角强度谱。我们的实验是基于使用同步加速器光源获取的数据；然而，为了准备使用传统X射线源进行更实际的实施，我们开发并评估了为泊松噪声设计的算法，泊松噪声是光子限制成像的特征。结果表明，MIR能够在低光子计数水平下工作，因此该方法很有希望用于传统的X射线源。结果还表明，除了产生新类型的对象描述外，MIR产生的图像比其前身Del MIR结果更准确，Del MIR结果以体模和生物标本的平面图像的形式显示。文中还给出了MIR用于计算机断层扫描的初步演示。
Conventional radiography produces a single image of an object by measuring the attenuation of an x-ray beam passing through it. When imaging weakly absorbing tissues, x-ray attenuation may be a suboptimal signature of disease-related information. In this paper we describe a new phase-sensitive imaging method, called multiple-image radiography (MIR), which is an improvement on a prior technique called diffraction-enhanced imaging (DEI). This paper elaborates on our initial presentation of the idea in Wernick et al (2002 Proc. Int. Symp. Biomed. Imaging pp 129-32). MIR simultaneously produces several images from a set of measurements made with a single x-ray beam. Specifically, MIR yields three images depicting separately the effects of refraction, ultrasmall-angle scatter and attenuation by the object. All three images have good contrast, in part because they are virtually immune from degradation due to scatter at higher angles. MIR also yields a very comprehensive object description, consisting of the angular intensity spectrum of a transmitted x-ray beam at every image pixel, within a narrow angular range. Our experiments are based on data acquired using a synchrotron light source; however, in preparation for more practical implementations using conventional x-ray sources, we develop and evaluate algorithms designed for Poisson noise, which is characteristic of photon-limited imaging. The results suggest that MIR is capable of operating at low photon count levels, therefore the method shows promise for use with conventional x-ray sources. The results also show that, in addition to producing new types of object descriptions, MIR produces substantially more accurate images than its predecessor, DEL MIR results are shown in the form of planar images of a phantom and a biological specimen. A preliminary demonstration of the use of MIR for computed tomography is also presented.