CN101532969A - System and method for phase-contrast imaging by use of X-ray gratings - Google Patents

System and method for phase-contrast imaging by use of X-ray gratings Download PDF

Info

Publication number
CN101532969A
CN101532969A CN 200810166472 CN200810166472A CN101532969A CN 101532969 A CN101532969 A CN 101532969A CN 200810166472 CN200810166472 CN 200810166472 CN 200810166472 A CN200810166472 A CN 200810166472A CN 101532969 A CN101532969 A CN 101532969A
Authority
CN
Grant status
Application
Patent type
Prior art keywords
ray
object
grating
absorption
system
Prior art date
Application number
CN 200810166472
Other languages
Chinese (zh)
Other versions
CN101532969B (en )
Inventor
康克军
黄志峰
丽 张
陈志强
李元景
刘以农
赵自然
刑宇翔
Original Assignee
同方威视技术股份有限公司
清华大学
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

Links

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
    • A61B6/48Diagnostic techniques
    • A61B6/484Diagnostic techniques involving phase contrast X-ray imaging

Abstract

The application relates to a system and a method for the phase-contrast imaging by use of X-ray gratings. The system comprises an X-ray device, a first absorption grating, a second absorption grating, a detection unit, a data processing unit and an imaging unit, wherein the X-ray device transmits an X-ray bundle to a detected object; the first and second absorption gratings are positioned in the direction of the X-ray bundle; the X-ray refracted by the detected object forms an X-ray signal with variable intensity through the first absorption grating and/or the second absorption grating; the detection unit receives and converts the X-ray with variable intensity into an electrical signal; the data processing unit processes and extracts refraction-angle information in the electrical signal, and utilizes the refraction-angle information to figure out pixel information; and the imaging unit constructs images of the object. In addition, the system and the method can also realize CT imaging by using a rotating structure to rotate the object so as to obtain refraction angles in a plurality of projection directions and the corresponding images, and use CT reconstruction algorithm to figureout refraction-index fault images of the detected object. According to the invention, the phase-contrast imaging of approximate decimeter-magnitude viewing fields under incoherent conditions can be realized by use of common X-ray machines or multi-seam collimator such as source gratings, as well as two absorption gratings.

Description

X射线光栅相衬成像系统及方法 X-ray phase-contrast imaging system and method grating

[0001] 技术领域 [0001] Technical Field

[0002] 本发明涉及透视成像领域,具体涉及用X射线对物体进行照相成像以及CT成像。 [0002] The present invention relates to fluoroscopic imaging, and in particular relates to an image forming objects using X-ray and CT imaging.

[0003] 背景技术 [0003] BACKGROUND OF THE INVENTION

[0004] 传统的X射线成像技术是利用物质材料对X射线的衰减特性来非破坏性地检查物体的内部结构。 [0004] The conventional X-ray imaging techniques is the use of biomass material to the attenuation characteristic X-ray non-destructive inspection of an internal structure of the object. 如果物体内部的各部分结构组成的密度差异明显,则传统的X射线成像技术的效果尤为显著。 If the difference in density of the internal structure of each part of the body composition significantly, the effect of the conventional X-ray imaging techniques is particularly significant. 但是,以轻元素(例如氢、炭、氮和氧)构成的物质,它们对X射线来说是弱吸收物质,所以用传统的X射线成像技术几乎看不到它们内部的具体结构。 However, to a light element (e.g. hydrogen, carbon, nitrogen and oxygen), a substance with a substance which is weakly absorbing X-rays, the so conventional X-ray imaging technology is almost not see a specific configuration of the interior thereof. 即使是用其它辅助的手段,例如给生物组织打上造影剂也很难得到清晰的图像。 Even with other auxiliary means, such as a biological tissue marked contrast agent it is difficult to obtain a clear image.

[0005] 二十世纪九十年代中期,由于第三代同步辐射装置的发展,硬X射线位相衬度成像(phase-contrast imaging,简称相衬成像)技术应运而生。 [0005] In the mid-1990s, the development of third generation synchrotron radiation device, hard X-ray phase contrast imaging (phase-contrast imaging, referred to as phase contrast imaging) technology is introduced. 相衬成像技术,就是通过捕捉X射线的相移信息来观察物体内部的电子密度变化,从而揭示物体的内部结构。 Phase contrast imaging technique, is to observe the electron density inside the object by capturing X-ray phase shift information, thereby revealing the internal structure of the object. 相衬成像技术使X射线成像的空间分辨率由毫米量级推进到微米量级甚至纳米量级,并将X射线成像可检测的物质范围由对X射线高吸收的重元素物质扩展到弱吸收的轻元素物质。 Phase contrast imaging X-ray imaging technology enables spatial resolution is propelled by the order of millimeters to microns or even nanometers, and the X-ray imaging range of substances can be detected by the heavy element substance extended X-ray absorption of the high-weak absorption the light element materials.

[0006] 至今,借助同步辐射射线源的高亮度和良好的相干性,相衬成像技术已经发展了至少4种的成像方法:干涉法、类同轴成像、衍射增强成像和光栅相衬成像等。 [0006] So far, by means of synchrotron radiation ray sources of high luminance and good coherence, phase contrast imaging methods have been developed for imaging of at least 4: interferometry, forming a coaxial type, the diffraction grating phase-contrast enhanced imaging and imaging . 这些技术与传统X射线成像技术、MRI技术、超声技术等各种现有成像技术相比具有独特的优势,因此,相衬成像技术已经成为X射线成像领域里最前沿的技术之一。 These various existing imaging techniques technology and traditional X-ray imaging, MRI technology, ultrasound technology has unique advantages compared to, therefore, phase contrast imaging technology has become one of the X-ray imaging in the forefront of technology. 然而,相衬成像技术对X射线源的苛刻要求和自身的成像特点,极大限制了它在医学上的临床应用。 However, the stringent requirements for phase contrast imaging X-ray source and the imaging characteristics of its own, which greatly limits its application in clinical medicine.

[0007] 首先,从X射线源方面来说,同步辐射装置的造价昂贵、体积庞大,视场小(十毫米量级),限制了它的应用范围。 [0007] First, the X-ray source side, the cost of expensive synchrotron radiation, bulky, small field of view (on the order of ten mm), limiting its scope of application. 另外一个选择是微焦点X射线源,它发出的X射线具有部分相干性,可以实现相衬成像。 Another option is a microfocus X-ray source, which emits X-rays having a partial coherence, phase contrast imaging can be achieved. 但是,微焦点X射线源亮度非常低,因此探测器需要曝光时间相当长(几十秒甚至几分钟),这也是临床应用所不能容忍的。 However, micro-focus X-ray source brightness is very low, so the detector requires a relatively long exposure time (several tens of seconds or even minutes), which is the clinical application can not tolerate. 如果能在通用X射线机上实现相衬成像,那么将是非常有实际价值和意义的事情。 If we can achieve phase contrast imaging on general purpose X-ray machine, it would be very practical value and significance of things.

[0008] 其次,从相衬成像方法的自身特点而言,干涉法、类同轴在实际使用中受到一定的限制。 [0008] Next, the phase contrast imaging method of its own characteristics, the interference method, subject to certain restrictions coaxial type in practical use. 由于干涉法、类同轴成像通过观察相干X射线的干涉现象或Fresnel衍射现象来获取位相信息,都需要具有很高空间相干性的X射线源和分辨率达微米量级的探测器。 Since interferometry, a coaxial type X-ray imaging by observing the interference of coherent Fresnel diffraction phenomena or to obtain phase information, the probe needs to have a high spatial coherence of the X-ray source and the resolution of the order of microns. 但是这两种装置都很昂贵,而且微米分辨率的探测器的面积一般都很小(几平方厘米左右),这就决定了整个成像系统的视场也比较小,从而做不了大样品的成像检查。 However, both devices are expensive, and the area of ​​the detector micron resolution are generally small (about a few square centimeters), which determines the field of view of the entire imaging system is relatively small, so that the imaging can not do a large sample an examination. 衍射增强成像方法虽然可以使用通用X射线机和分辨率不那么高的探测器来实现高对比度(密度分辨率)的物体边缘增强的成像,但是光路中单色晶体的单色作用使得视场扁小,单色光亮度降低。 Although the diffraction enhanced imaging method to achieve a high contrast (density resolution) of an object can be imaged edge enhancement using a general purpose machine and the X-ray detector resolution is not so high, but the effect of the monochromatic light path such that the field of view of the monochromator crystal flat small, monochromatic luminance decreases. 因此,这些相衬成像方法在医学临床应用中具有一定的局限性。 Thus, the phase-contrast imaging method has some limitations in medical clinical applications.

[0009] 在2002年,瑞士PSI(Paul Scherrer学院)的David C等人年在ESRF(European Synchrotron Radiation Facility,欧洲同步辐射装置)上用2个相位光栅和1个分析晶体形成的光路上首次实现了基于光栅衍射Tabot效应的硬X射线光栅相衬成像方法。 [0009] In 2002, the optical path Switzerland PSI (Paul Scherrer Institute) with the person-like David C 2 and a phase grating formed on the crystal analysis of ESRF (European Synchrotron Radiation Facility, European Synchrotron Radiation Facility) for the first time a phase-contrast X-ray imaging method based on hard diffraction gratings Tabot effect. 2003年,日本的Momose A等人在Spring-8上也展开了基于位相光栅和吸收光栅的光栅相衬成像方法的研究,提出用两个光栅提取一阶位相信息的技术。 In 2003, Japanese Momose A et al in the Spring-8 also carried out research on phase grating and absorption grating is the grating phase-contrast imaging method, the proposed technique to extract a first order phase information of two gratings. 在2003年,瑞士PSI的Weitkamp T和Pfeiffer F等人在David C工作的基础上在SLS(Swiss Light Source,瑞士光源)和ESRF上同样实现了基于2个光栅的相衬成像技术。 In 2003, PSI's Swiss Weitkamp T and Pfeiffer F et al on the basis of the work of David C on SLS (Swiss Light Source, the Swiss Light Source) and the ESRF also achieved based on phase contrast imaging technique two gratings. 然而,上述方法都是基于同步辐射射线源上进行的,视场都很小,极大限制了相衬成像的应用。 However, the above methods are based on a synchrotron radiation source for the field of view are small, which greatly limits the application of phase contrast imaging.

[0010] 在2006年,Pfeiffer F等人于2006年取得了重要的突破,他们使用三块功能不同的光栅实现了基于通用X射线机的光栅相衬成像方法,克服了衍射增强成像方法视场小的缺点,得到了接近64mm×64mm大小视场,从此为相衬成像技术的实际应用开拓了切实可行的道路。 [0010] In 2006, Pfeiffer F, who in 2006 made an important breakthrough, they use three different functions gratings grating phase-contrast imaging method based on common X-ray machines, to overcome the diffraction enhanced imaging field of view method minor faults, to give a close field of size 64mm × 64mm view, to develop a feasible way from practical application of phase contrast imaging technique. 但是,他们所建的光栅相衬成像系统的成像时间比较长(曝光时间为40秒),无法进行活体实验。 However, the imaging time they built grating phase-contrast imaging system is relatively long (40 seconds exposure time) can not be performed in vivo experiments. 这种方法使用了源光栅(sourcegrating)将X射线机射线源分成一系列宽度在25微米到50微米之间的、互不相干的线射线源。 This method uses the source grating (sourcegrating) the X-ray-ray source into a series of machine width, unrelated line between radiation source 25 microns to 50 microns. 单个线射线源的发出的X射线是部分相干的,与相位光栅作用产生Talbot效应。 X-ray radiation source emits single wire is partially coherent, with the phase grating to produce the Talbot effect action. 在本质上,这种成像方法利用源光栅使通用X射线机发出的非相干光产生部分相干性,再利用光栅衍射的Talbot效应来实现相衬成像。 In essence, such an image forming method using non-coherent source grating Universal emitted X-ray machine coherence light generating portion, and then using the Talbot effect diffraction grating to achieve phase-contrast imaging.

[0011] 因此,现已有的所有的相衬成像方法(包括光栅相衬成像方法)的本质是利用相干或者部分相干的X射线的干涉或衍射现象来增强辐射图像的低对比度分辨率(也就是密度分辨率)。 [0011] Accordingly, there is now the nature of all the phase-contrast imaging method (phase-contrast imaging method comprises a grating) is used to enhance the low contrast resolution of an image using coherent radiation or the coherent part of the X-ray diffraction or interference phenomena (also It is the density resolution). 因为通用X射线机发出的X射线是多色、非空间相干的,根据Talbot效应原理,对于现有的光栅相衬成像技术来说,必须使用3个不同功能的光栅来实现,而且,相位光栅和吸收光栅之间的距离(被称为Talbot距离)必须选取恰当,才能满足多色条件下Talbot效应的成像要求。 Since the X-rays emitted by general X-ray machine is polychromatic, non-coherent space, according to the principle of the Talbot effect, the prior art phase-contrast imaging of the grating, the grating must use three different functions is achieved, and the phase grating distance between the grating and the absorption (referred to as the Talbot distance) must be selected appropriately in order to meet the requirements of the Talbot effect under the imaging conditions multicolor. 为了实现在硬X射线的光栅衍射,对光栅的制作提出了很高的要求:微米量级周期的精度、大深宽比。 In order to achieve the hard X-ray diffraction grating, grating for making high demands made: accuracy microns cycle, large aspect ratio. 这些不利因素将极大限制光栅相衬成像技术在医学和工业上的实际应用。 These negative factors will greatly limit the practical application of phase contrast imaging grating technology in medicine and industry.

[0012] 发明内容 [0012] SUMMARY OF THE INVENTION

[0013] 本发明提出一种采用非相干方法实现的相衬成像系统,其使用两个吸收光栅在多色、非空间相干的射线源(通用X射线机)下获得X光穿过物体后的一阶微分相移信息,从而由此重建物体的图像。 [0013] The present invention provides a phase contrast imaging system using noncoherent implemented method, which uses two absorption grating in a multicolor, non-spatially coherent X-ray source is obtained under (Universal X-ray machine) Light passing through the first differential phase shift information, to thereby reconstruct the image of the object.

[0014] 根据本发明的一个方面,提供一种X射线光栅相衬成像系统,用于对物体进行成像检测,该系统包括:X射线发射装置,用于向被检测物体发射X射线束,其中在大焦点光源情况下可以添加一个多缝准直器(即源光栅)来产生一组小焦点线光源以向被检测物体发射X射线束;第一和第二吸收光栅,二者依次位于X射线方向上,经被检测物体折射的X射线经由该第一和第二吸收光栅形成强度变化的X射线信号;检测单元,接收所述强度变化的X射线,将X射线信号转换为电信号;以及数据处理单元,处理所述电信号,提取电信号中的X射线折射角信息,并利用所述折射角信息取得物体的像素信息;成像单元,利用所述像素信息重建物体的X射线投影图像。 [0014] In accordance with one aspect of the present invention, there is provided an X-ray phase-contrast grating imaging system for imaging an object is detected, the system comprising: X-ray emission means for emitting X-ray beams to the object to be detected, wherein in the case of large focal spot can add more than one light source slit collimator (i.e., the source grating) to generate a set of small linear light sources to emit a focus X-ray beam to the object to be detected; the first and second absorption gratings, both located in order X the radiation direction, the refracted X-ray through the object is detected first and second X-ray signal intensity variation absorption grating is formed; detecting means, the intensity of the received X-rays changes, the X-ray signal into an electric signal; and a data processing unit, processing the electrical signal, extracting a refraction angle X-ray information in the electrical signal, and using the information acquired refraction angle of the object pixel; imaging unit, using reconstructed pixel information of the X-ray projection images of the object .

[0015] 根据本发明的第二方面,提供一种利用X射线对物体进行成像检测的方法,该方法包括:向被检测物体发射X射线束,其中在大焦点光源情况下可以添加一个多缝准直器(即源光栅)来产生一组小焦点线光源以向被检测物体发射X射线束;使经物体折射的X射线经由第一和第二吸收光栅形成强度变化的X射线信号;接收所述强度变化的X射线,并将接收到的X射线信号转换为电信号;以及从所述接收的电信号中,提取X射线束经过物体的折射角信息,以及利用预定的算法得出物体的像素信息。 [0015] According to a second aspect of the present invention, there is provided a method using X-ray imaging of the object detection, the method comprising: transmitting X-ray beam to the object to be detected, wherein in the case where large focal spot can add more than one light source slit a collimator (i.e., the source grating) to generate a set of small linear light sources to emit a focus X-ray beam to the object to be detected; the X-ray refracted by the object are formed of X-ray intensity change signal via a first and a second absorption grating; receiving the intensity change of X-rays, X-rays and converts the received signal into an electrical signal; and said received electrical signal, extracting a refraction angle information of the X-ray beam passes through the object, and the object obtained by using a predetermined algorithm pixel information.

[0016] 根据本发明的第三方面,提供一种X射线光栅相衬CT成像系统,其除了包括第一方面所述的系统组成外,还包括一个旋转结构,用于使得被检测的物体相对于X射线源和光栅、检测单元等进行旋转。 [0016] According to a third aspect of the present invention, there is provided a phase-contrast X-ray CT imaging system grating, which in addition to the first aspect includes a system consisting of an outer, further comprising a rotation mechanism for causing an object to be detected is relatively rotating the grating and the X-ray source, detecting unit and the like. 所述CT成像系统在CT模式下,可以通过旋转被检测的物体,获得各个投影角度下的折射角信息及相应的平面像素信息,进而利用预定算法来重构物体内部的折射率分布的断层图像。 The CT imaging system in CT mode, by rotating the object to be detected to obtain information on the refraction angle corresponding to the plane and the pixel information at each projection angle, and further by using a predetermined algorithm to reconstruct a refractive index distribution in the tomographic image of the object .

[0017] 本发明最大的优点是完全摆脱了对射线源相干性的依赖,没有Tablot距离的限制,而且能使用微米量级以上的周期的光栅实现近分米量级视场的非相干条件下的相衬成像。 [0017] The greatest advantage of the present invention is completely free from dependence on the coherence of the radiation source, there is no limitation Tablot distance, and can use more than micrometer period gratings near dm conditions the incoherent field of view of the order of the phase contrast imaging. 与传统X射线成像相比,本系统能够对弱吸收物质(例如乳腺、血管和肌肉等软组织、纤维材料、昆虫等)进行高对比度的成像。 Compared with the conventional X-ray imaging, the present system is capable of high-contrast imaging of the weak absorbing material (e.g. breast, blood vessels and other soft tissue and muscle, fibrous material, and insects). 与现有相衬成像相比,无需考虑光源的相干性条件,同时也降低了微米量级周期、大深宽比光栅的制作难度要求,并可很容易地推广到使用高能量(>40keV)X光进行相衬成像。 Compared with the conventional phase contrast imaging, regardless of the source coherence condition, but also reduces the cycle microns, large aspect ratio of the difficulty of making the grating requirements, and can be easily extended to high energy (> 40keV) X-ray phase contrast imaging. 而且,本发明的相衬成像系统与传统X射线成像系统天然兼容,只需要在传统X射线成像上架设两光栅平动旋转系统即可实现。 Furthermore, phase-contrast imaging system of the present invention with the conventional X-ray imaging system compatible natural, only need to set up two grating moving in the rotating system can be implemented on a conventional X-ray imaging. 本发明将进一步降低相衬成像实际应用的门槛,为相衬成像走向医学、生物学、工业材料等领域应用开拓崭新的思路和途径,具有重大的实际意义和应用价值。 The invention will further lower the threshold for the practical application of phase contrast imaging for the phase contrast imaging applications to medicine, biology, and other industrial materials to develop new ideas and approaches, it is of great practical significance and value.

[0018] 附图说明 [0018] BRIEF DESCRIPTION OF DRAWINGS

[0019] 图1示出本发明的光栅相衬成像系统的示意图; [0019] FIG. 1 shows a schematic grating phase-contrast imaging system according to the present invention;

[0020] 图2示出在不同焦点尺寸的射线源照射条件下,两个光栅使用相位步进技术时所对应的模拟光强变化曲线; [0020] FIG. 2 shows at different irradiation conditions of ray source focal spot size, the use of two phase stepping technique gratings corresponding analog intensity variation curve;

[0021] 图3示出X光与物体相互作用后的波阵面变化情况; [0021] FIG. 3 illustrates the wavefront of X-rays after interaction with the object changes;

[0022] 图4示出X射线被物体折射的示意图; [0022] FIG. 4 shows a schematic X-rays are refracted object;

[0023] 图5示出两个吸收光栅的对X射线的“光闸”作用; [0023] FIG. 5 shows two "shutter" effect on the absorption grating for X-rays;

[0024] 图6a和图6b分别示出根据本发明的CT模式的两种方式; [0024] Figures 6a and 6b illustrate two ways in accordance with the CT mode of the present invention;

[0025] 图7示出在利用光栅相位步进技术时检测面上某点在经被测物体折射后与未经折射情况下所检测的X射线的光强变化曲线的比较; [0025] FIG. 7 shows the grating phase stepping technique utilizing a detection surface of the object to be measured after comparison of light refracted X-ray intensity curve in the case where the detected without refraction;

[0026] 图8a-8d分别示出使用折射角重建图像的三个示例; [0026] FIGS. 8a-8d show three example uses a refraction angle of a reconstructed image;

[0027] 图9示出本发明中使用莫尔干涉法所测条纹的示意图; [0027] FIG. 9 shows a schematic view of the present invention using Moire interferometry measured fringes;

[0028] 图10示出根据本发明一个实施例的示意图,其中在射线源前面加一个多缝准直器(即源光栅);以及 [0028] FIG. 10 shows a schematic of one embodiment of the present invention, wherein the front-ray source plus a multi-slit collimator (i.e., the source grating); and

[0029] 图11示出根据本发明另一实施例的示意图,其中被测物体放置在两吸收光栅之间。 [0029] FIG. 11 shows a schematic view of another embodiment of the present invention, wherein the object is placed between the two absorption grating.

[0030] 具体实施方式 [0030] DETAILED DESCRIPTION

[0031] 根据本发明构思设计的一种X射线光栅相衬成像系统,参见附图1所示,其主要包括以下部分: [0031] According to an X-ray phase-contrast imaging system of grating design concept of the present invention, see Fig. 1, which includes the following components:

[0032] X射线发射装置(图1中用射线源表示),其用于向被检测物体(图中用物体表示)发射X射线束,其中在大焦点光源情况下可以添加一个多缝准直器(即源光栅)来产生一组小焦点线光源以向被检测物体发射X射线束;第一和第二吸收光栅(在图中分别表示为光栅A和光栅B,其周期分别为p1、p2),其平行地依次位于X射线束的发射方向上;检测单元,图中用探测器表示,用于接收所述X射线,通过信号转换技术(例如,数字化摄影技术(DR))将X射线信号转换为电信号;以及数据处理单元(图中并未示出),用于从所述电信号计算得出X射线经过被检测物体后的光强变化信息,并利用所述光强变化值计算得出X射线的折射角信息,以及利用折射角信息计算出所述被检测物体的像素信息;成像单元(图中未示出),根据所述的折射角信息(像素信息)重建物体的图像并显示出。 [0032] X-ray emission device (FIG. 1 by radiation source shown) for the object to be detected (object represented by the figure) emitted X-ray beam, wherein the light source in the case where large focal spot can add more than one slit collimator (i.e. the source grating) to generate a set of small linear light sources to emit a focus X-ray beam to the object to be detected; the first and second absorption grating (in the figures denoted as a grating and the grating B, which are periods p1, P2), which are sequentially positioned on the emitter parallel direction of the X-ray beam; detecting unit, FIG detector by said means for receiving the X-rays through the signal conversion techniques (e.g., digital photography (the DR)) to X ray signal into an electric signal; and a data processing unit (not shown) for detecting the light intensity change information object, and using the change in light intensity through the X-ray derived from the electrical signal calculation value calculated refraction angle X-ray information, and the information is calculated using the angle of refraction of the pixel information of an object to be detected; an imaging unit (not shown), the reconstruction of the refraction angle according to the object information (pixel information) and an image display.

[0033] 如后文所述,在X射线光栅相衬成像系统的CT使用模式中,可以获得多个投影面的折射角信息,病根据所述折射角信息利用预定CT构图算法来重构物体内部的折射率分布的断层图像。 [0033] As described later, in a mode using an X-ray CT imaging system phase-contrast grating, the angle of refraction can be obtained a plurality of projection information to reconstruct the object's disease patterning using a predetermined algorithm based on the CT information refraction angle a tomographic image of the interior of the refractive index profile.

[0034] 现就各组成部分及具体操作进一步说明。 [0034] Now on the components and the specific operation further described.

[0035] X射线发射装置 [0035] X-ray emission device

[0036] 不同于前面背景技术中提到的3光栅相衬成像技术,本发明的相衬成像可以使用非相干的射线源直接照射。 [0036] 3 different from the grating phase contrast imaging technique mentioned in the foregoing background art, the present invention may be phase-contrast imaging using radiation sources directly irradiated with incoherent. 也就是说,本发明的相衬成像技术不依靠射线源的相干性(包括时间相干性和空间相干性),也不需要考虑光栅衍射或者Talbot效应,也能得到相衬图像。 That is, phase contrast imaging technique of the present invention does not depend on the coherence of the radiation source (including temporal coherence and spatial coherence), or does not need to consider the diffraction grating of the Talbot effect, the phase contrast image can be obtained. 当不需要考虑X射线的相干性时,成像系统可用几何光学近似理论来描述。 When not considering coherence X-rays, the imaging system may be used to describe the theory of geometrical optics approximation. 根据光衍射原理,X射线与光栅A不产生衍射的条件是: The principle of light diffraction, X-ray conditions with no diffraction grating A is:

[0037] [0037]

[0038] 可以看出,当光栅A的周期即p1越大,则方程式右侧的值越小,因此本发明采用较大周期的光栅也能够得到满足要求的相衬图像。 [0038] As can be seen, when the grating period A p1 i.e. the larger, the smaller the value of the right side of the equation, the present invention is thus the use of larger grating period of the phase contrast image can be obtained to meet the requirements. 假设光栅A的周期为20微米,射线源到光栅距离2米,则 Suppose the grating period A is 20 microns, the grating distance to the radiation source 2 meters is

[0039] [0039]

[0040] 而通用X射线机的焦点尺寸至少几十微米或几百微米以上,所以通用X射线机满足本发明系统的要求。 Above [0040] and common X-ray focus size machine at least several tens of microns or several hundreds of microns, so the general X-ray machine to meet the requirements of the present system. 20微米周期的光栅与现有光栅相衬成像技术要求2或4微米周期的光栅相比,制作难度将大大降低。 20 microns as compared to gratings the grating period of the prior art phase-contrast imaging in claim 2 or 4 micron period, difficulty level will be greatly reduced.

[0041] 然而,也并非射线源焦点尺寸越大就越好,它受制于两个吸收光栅的相位步进技术的精度要求。 [0041] However, it is not the larger-ray source focal spot size the better, it is subject to two phase stepping precision absorption grating technology. 图2所示,是在例如两吸收光栅的周期分别为20微米和22微米,源到光栅A距离2米,两光栅之间距离0.2米时,在不同焦点尺寸的射线源照射条件下,两光栅使用相位步进技术时某点所对应的模拟光强变化曲线。 As shown in FIG. 2, for example, in the two absorption grating period were 20 m and 22 m, the distance A source grating to 2 meters, 0.2 meters from the grating between the two, under the condition of different focal spot size of the irradiation ray source, two grating analog phase stepping technique using a point corresponding to the light intensity curve. 其中横坐标为步进大小(0.5微米/步),纵坐标为光强值。 Wherein the abscissa is the step size (0.5 micrometers / step), the ordinate is the light intensity value. 要注意的是,根据式(2)估算的结果,焦点尺寸为1微米的射线源发出的X射线是相干的,但为了方便和较大焦点的射线源进行比较,也同样在几何光学近似下的获得的。 It is noted that, according to formula (2) results of the estimation, focus size of the X-ray radiation emitted by the source 1 micron are coherent, but in order to facilitate comparison and a larger-ray source focal point, also in the geometrical optics approximation obtained. 从图2发现,焦点尺寸越大,光强变化曲线就越平滑,直至焦点尺寸等于220微米时成为一条直线。 , Found that the larger the focal spot size of FIG. 2, the smoother the curve of light intensity, until the focus size is equal to 220 micrometers HORIZ.POSITION. 也就是说相位步进技术不再起作用。 That is no longer active phase stepping technique. 当焦点尺寸大于220微米时,光强变化曲线呈现其它变化趋势。 When the focus size greater than 220 microns, the intensity variation curve exhibits other trends. 可以推算出射线源焦点尺寸的临界值为p0,critical: Can calculate the radiation source focal spot size threshold value is p0, critical:

[0042] [0042]

[0043] 根据图2所示,因为当焦点尺寸大于这个临界值时仍有光强变化,仍可根据这一点获得相衬效果的图像,但衬度效果没有当焦点尺寸小于p0,critical的情况要好。 [0043] According to FIG. 2, since the light intensity changes when the focus is still larger than the size threshold, the image can still be obtained that the phase contrast effect, but the contrast effect is not the case when the focal spot size of less than p0, critical to better. 根据上述结果,可以得出,在p0,critical范围内,焦点尺寸越小,光强变化曲线越陡,那么提取出来的相衬图像的衬度也越高。 From the above results, it can be concluded in p0, critical range, the smaller the spot size, the steeper the curve of change in light intensity, the contrast of phase contrast image of the extracted higher. 优选情况下,射线源焦点尺寸大小p0要求不超过p0,critical的一半。 Preferably, the radiation source focal point size was not exceeded p0 p0, the half critical. 当然,如果射线源焦点尺寸p0大于该临界值的话,也可以采用其他方式来解决此问题。 Of course, if p0-ray source focal spot size is larger than the threshold value, it may be other ways to solve this problem. 其中一种方法是在焦点尺寸大于p0的射线源之前放置多缝准直器(即源光栅)(例如,图10所示),其周期ps=Mp0,critical,M=1,2,3,...。 One method is to place multi-slit collimator focal spot size is larger than before the p0-ray source (i.e., source grating) (e.g., FIG. 10), which period ps = Mp0, critical, M = 1,2,3, .... 这样将大射线源细分为一系列等效的小焦点线射线源,为了提高图像衬度,每个小焦点线射线源的焦点尺寸大小p0,i也要求不超过p0,critical的一半。 Such a large number of equivalent ray source subdivided into small ray source focal line, in order to improve the image contrast, the focus of each of the small size of the focal line p0-ray source, i of p0 also requires no more than, half the critical. 当然,射线源焦点大小也可以大于p0,critical,这样相衬图像的衬度由当时的光强变化曲线来决定。 Of course, ray source focal spot size may be larger than p0, critical, so that the phase contrast image contrast is determined by the time of the light intensity curve. 自然,本领域技术人员可以理解,在采用多缝准直器(即源光栅)的情况下,所述距离l实际上是光栅A与该多缝准直器(即源光栅)之间的距离,而不是与实际射线源之间的距离。 Distance Naturally, the skilled artisan will be appreciated, in the case of multi-slit collimator (i.e., the source grating), and the fact that the grating A multi-slit collimator distance L (i.e., source grating) between the distance between the radiation source rather than the actual. 在射线源之前放置多缝准直器(即源光栅)来形成具有期望焦点大小的光源的方法为本领域技术人员所公知,因此这里将不再详述。 Multi-ray source is placed before the slit collimator (i.e., the source grating) having a light source to form a desired focal spot size method is known to those skilled in the art, and therefore will not be described in detail herein.

[0044] 由于射线源可以是焦点尺寸较大的X射线源,因此通常的商用X射线机即可满足要求。 [0044] Since the radiation source may be a large focus size of the X-ray source, it is often a commercial X-ray machine to meet the requirements. 区别于传统X射线成像,本发明的相衬成像技术要求射线装置的工作电压最好设置在5-40kVp条件下(具体数值由吸收光栅的金高度决定,也就是说金的高度越高,允许使用的工作电压则越高)。 Different from the conventional X-ray imaging, contrast imaging technique of the present invention requires operating voltage ray apparatus is preferably provided on the lower 5-40kVp conditions (specific values ​​determined by the height of the gold absorption grating, i.e. the higher the height of the gold, allowing use of the higher operating voltage).

[0045] 优选地,本系统适合使用小焦点源,它的焦点尺寸优选在10-1000微米之间。 [0045] Preferably, the present system is suitable for small focal spot, its focus size is preferably between 10-1000 microns. 但如果使用微焦点设备(焦点小于10微米),则由于射线源的空间相干性增加,吸收光栅将产生Talbot效应。 However, if using a microfocus device (focus less than 10 microns), the increase in coherence due to the spatial-ray source, absorption grating will produce the Talbot effect. 这种情况和Pfeiffer F的光栅相衬方法的原理一致。 This situation consistent with the principles and methods of the phase-contrast grating of Pfeiffer F. 这样,另外一块吸收光栅只有放置在Talbot距离的位置点上才能有比较好的成像效果。 Thus, an additional absorption grating are placed only on the position of the Talbot distance of the point in order to have better imaging results. 如果使用焦点大于100微米的射线装置,那么图像边缘模糊会增加,从而不利于图像衬度的增强。 If the device-ray focal point of greater than 100 microns, the edges of the image blur increases, which is not conducive to an enhanced image contrast. 对于这种情况,可以在射线源前面放置多缝准直器(即源光栅)(每条缝的宽度大小在10-200微米之间),如图10所示,其周期ps=Mp0,critical,M=1,2,3,...。 In this case, radiation source may be placed in front of the multi-slit collimator (i.e., the source grating) (each width of the slit size between 10-200 microns), 10, which period ps = Mp0, critical , M = 1,2,3, .... 这样将大射线源细分为一系列等效的小焦点尺寸线射线源,虽然图像的空间分辨率仍由射线源焦点尺寸决定,但各线射线源产生的衬度高的图像叠加在一起,仍能得到一个衬度相当高的相衬图像。 Such a large-ray source subdivided into a series of small focal spot size equivalent line-ray source, the spatial resolution of the image while still decide ray source focal spot size, but the image line high radiation sources to produce the respective liner superimposed together, still obtain a relatively high contrast image contrast.

[0046] 光栅部分 [0046] The grating portions

[0047] 通用X射线机发射的X射线束可以是扇束、锥束或平行束。 [0047] X-ray beam emitted by the general X-ray machine may be a fan-beam, cone-beam or a parallel beam. 本发明中优选地是锥束,因此本发明相衬成像系统所采用的两个吸收光栅的周期也优选地要求成几何比例关系,即: The present invention is preferably a cone-beam, thus the absorption grating period of two phase-contrast imaging system of the present invention also preferably employed proportional geometric requirements, namely:

[0048] [0048]

[0049] 其中,l为射线源到第一个光栅A的距离,d为两个吸收光栅A和B之间的距离。 [0049] wherein, l is the distance from radiation source to the first grating A, d is the distance between the absorption two gratings A and B.

[0050] 因此,与原有光栅相衬成像技术相比,本发明的相衬成像照相及其CT系统中两光栅之间的距离d,与所发射的X射线的波长λ无关,因此与Talbot距离无关,可根据实际情况需求由式(3)和(4)而定。 [0050] Therefore, as compared with the original phase contrast imaging grating, the distance d between the phase-contrast imaging camera according to the present invention and two grating CT system, independent of the wavelength λ of the emitted X-rays, thus Talbot independent of the distance, according to the actual needs of the situation by the formula (3) and (4) may be.

[0051] 又如图1所示,光栅部分包括两个吸收光栅,光栅A和光栅B,其结合使用用于提取穿过物体的X射线的一阶相位变化信息。 [0051] Another example is shown in FIG. 1, the grating portion comprises two absorption grating, and the grating A grating B, which in combination with a step for extracting the phase change through the X-ray information of the object. 具体地,对于吸收光栅,一般利用MEMS技术在硅片衬底上电镀上重金属材料(例如Au)线条作为光栅不透光部分;另外也可使用在重金属材料上刻划出光栅。 In particular, the absorption grating, typically on a silicon substrate using a heavy metal material (e.g. Au) as raster lines opaque portion electroplating MEMS technology; they may also be used on heavy metals depicts the grating material. 光栅A和光栅B平面都平行于探测器平面(XY方向)。 A grating and the grating plane B are parallel to the detector plane (XY direction). 光栅的面积大小决定了整个相衬成像系统的视场大小。 Grating determines the size of the area size of the overall field of view of phase contrast imaging system. 举例说明,若光栅的衬底为4英时硅片,则系统的视场在直径10cm的范围内。 Way of example, if the substrate is a grating 4 inches wafer, the field of view of the system is in the range of 10cm in diameter.

[0052] 优选地,两个吸收光栅的周期在0.1-30微米之间。 [0052] Preferably, the absorption grating is two cycles between 0.1 to 30 microns. 所述光栅使用重金属作为吸收材料,以金(Au)为例,金的高度由使用的X射线的能量决定,在10-100微米之间。 The heavy metal grating used as an absorbent material, gold (Au), for example, gold is determined by the height of the X-ray energy is used, between 10 to 100 microns. 例如,对20keV的X射线来说,金的高度大于16微米能阻挡90%的X射线,这样能获得衬度比较好的相衬图像。 For example, for 20keV X-ray, the height is greater than 16 microns of gold can block 90% of X-rays, so that good contrast can be obtained the phase contrast image. 其中,光栅A的周期为p1,光栅B的周期为p2,占空比(dutycycle)一般为1,也可以为其它占空比。 Wherein A is the grating period p1, B is the grating period p2, the duty cycle (dutycycle This is the) generally 1, may be a duty cycle other. 如图1所示,两个光栅之间的距离为d。 As shown in FIG. 1, the distance between the two grating d.

[0053] 检测单元 [0053] The detecting unit

[0054] 检测单元包括探测器,故图1中用探测器表示所述检测单元,用于检测和记录X射线的波阵面上的强度变化。 [0054] The detecting means comprises a detector, the detector represented by Fig. 1 so that the detecting unit, an intensity change in the wavefront of X-ray detection and recording. 优选地,所述探测器可以是矩阵探测器,其中的每个探测元可以检测射到该单元上的X射线的强度变化。 Preferably, the detector may be a detector array, wherein each detection element may change the intensity of the X-rays incident on the detection unit. 本系统中的(X射线)探测器,与其它相衬成像方法相比,对探测器的空间分辨率(象素大小)的要求不高:不必要求十几微米、甚至几微米的高分辨率,而是可只使用几十微米或几百微米量级的分辨率。 This system (X-ray) detectors, phase-contrast imaging as compared to other methods, the spatial resolution of the detector (pixel size) of less demanding: ten microns is not necessarily required, and even a few microns high resolution but can be used only tens or hundreds of microns micron resolution. 当然,如果探测器的空间分辨率越高,则最终相衬图像的信息越清晰。 Of course, if the higher spatial resolution of the detector, the sharper the final phase contrast image information. 由于相衬成像的优点是能提高图像的密度分辨率(对比度分辨率),所以数字化摄影技术DR对探测器的动态范围有比较高的要求(>12bits)。 Because of the advantages of phase contrast imaging is the ability to increase the density of image resolution (contrast resolution), so digital photography requires a relatively high DR (> 12bits) the dynamic range of the detector. 每个探测元可以探测到射到其上的X射线的光强变化(如图7所示)。 Each detection element can detect the change of light intensity incident thereon X-rays (Figure 7). 其中,光强可以转变为电信号。 Wherein the light intensity can be converted into an electric signal.

[0055] 提取X射线束经过物体的折射角信息 [0055] extracted refraction angle X-ray beam through the object information

[0056] 现以举例方式,说明利用例如数字化摄影技术(DR)从接收到的信号中提取X射线的一阶相位信息,以及进而得到折射角信息。 [0056] By way of example is now described using the example of digital photography (DR) extracting a first order X-ray phase information from the received signal, and thus the angle of refraction to obtain the information.

[0057] 众所周知,X射线具有“波粒二象性”。 [0057] is well known, X-rays having a "wave-particle duality." 以波动性来看,X射线具备透射、反射、折射、偏振、相干和不相干散射、衍射等波动性质。 In view of volatility, X-rays have transmission, reflection, refraction, polarization wave nature, the coherent and incoherent scatter, diffraction. 当X射线穿过某一物体的时候,X射线的振幅因为物体对它的吸收而减弱;同时,X射线与物质原子相干散射使X射线产生了相移(phaseshift),宏观上表现为X射线的波阵面产生变形。 When the X-rays passing through an object, the amplitude of the X-ray absorption of the object because of its weakened; at the same time, X-rays coherently scattered atoms and the material had the X-ray phase shift (phaseshift), X-ray showed macroscopically wavefront deformation. 也就是说,X射线在穿过物体时发生了折射现象,如图3所示。 That is, X-rays when the refraction through an object, as shown in FIG. 在宏观上,X射线与物质之间的相互作用可以用物质对X射线的复折射率n来描述: On the macro level, the interaction between the X-rays with matter substance can be described by an X-ray of the complex refractive index n:

[0058] n=1-δ-iβ (5) [0058] n = 1-δ-iβ (5)

[0059] 其中δ与物质的相移截面p相关,β与物质的线性吸收系数μ相关,它们之间的关系如下表示 [0059] wherein δ and substance-related phase shift sectional p, associated with beta] linear absorption coefficient μ substance, the relationship between them is represented as follows

[0060] [0060]

[0061] 其中λ为X射线的波长,δ被称为位相因子,β被称为吸收因子。 [0061] wherein λ is the wavelength of X-rays, δ is called phase factor, β is called absorption factor. 对X射线来说,δ一般为10-5左右,所以n小于1,因而X射线在物质分界面上只发生微小的折射,可用折射角Δθ表示(约为微弧度量级)。 For X-ray, [delta] is generally about 10-5, it is less than n 1, and thus a slight refraction at the boundary surface X-ray generating material is only available Δθ represents the angle of refraction (on the order of about microradians). 假设在二维XY平面上,X射线沿笛卡儿坐标系X轴方向传播,如图4所示,被物体折射的X射线的传播偏离原来方向的折射角近似为 Assuming a two-dimensional XY plane, the X-ray in a Cartesian coordinate system X-axis direction propagation, as shown, the object is refracted propagating the X-ray refraction angle deviates from the original direction to approximately 4

[0062] [0062]

[0063] 其中Φ(y)表示X射线沿传播路径M上的总相移。 [0063] where Φ (y) represents the total phase on X-ray M shift along the propagation path. 经过物体内部某几何点的X射线的相移为p(x,y)dx,则沿传播路径积分可求得总相移为 After X-rays with a geometry point inside the object shift is p (x, y) dx, the integral along the propagation path can be obtained for the total phase shift

[0064] [0064]

[0065] 结合式(7)和(8),得出 [0065] The binding of formula (7) and (8), obtained

[0066] [0066]

[0067] 式(9)表明,折射角Δθ是物体内部折射率一阶微分的沿传播路径的积分。 [0067] Formula (9) indicates that the object is an integral internal refraction angle Δθ order differential of a refractive index along the propagation path. 只要我们能够测量出折射X射线的折射角Δθ,就可根据式(9)并结合相衬CT重建方法求解出物体内部折射率n的分布。 As long as we are able to measure the X-ray refracted refraction angle Δθ, it can be according to formula (9) in combination with phase-contrast CT reconstruction method for solving the distribution of the refractive index n of the interior of the object.

[0068] 因此,如何测量折射角Δθ是本发明的两光栅相衬成像技术的核心。 [0068] Thus, how to measure the refraction angle Δθ is the core of the present invention, two grating phase contrast imaging technique. 根据几何光学近似理论,两吸收光栅的作用相当“光闸”一样。 The theory of geometrical optics approximation, two absorption grating effect equivalent "shutter" the same. 当两吸收光栅相对运动的时候,光栅对X射线来说就像闸门一样时开时闭,从而引起检测单元的探测元上的光强变化。 When the two gratings relative movement absorption grating for X-rays is as close as when the shutter opening time, thereby causing change in light intensity on the detection element detection unit. 例如参见图5所示,从两光栅相衬成像系统的二维平面图观察。 See, for example, as shown in FIG. 5, a two-dimensional phase-contrast imaging system is viewed in plan from the two gratings. 举例说明,在没有物体的情况下,X射线1被光栅A遮挡即被Au吸收,X射线2不被两光栅遮挡而顺利到达探测元。 Way of example, in the case where no object, X-rays 1 is blocked by the absorption grating A Au i.e., X-rays 2 is not blocked two grating successfully reach the detection element. 当在光路上放上物体后,X射线1被物体折射后的折射角为Δθ1,X射线2被物体折射后的折射角为Δθ2。 When the object is placed on the optical path, X-rays after being refracted angle of refraction of the object 1 ?? 1, X-rays after the object is refracted angle of refraction 2 is Δθ2. 这时情况发生变化,X射线1因折射而顺利避开两光栅的遮挡到达探测器,X射线2则被光栅B遮挡从而被Au吸收。 At this time the situation is changed, X-rays one by refraction successfully blocked to avoid two gratings to the detector, X-ray shield 2 were thus raster B is absorbed Au. 这样一来,探测器所探测到的光强变化反映了X射线被物体折射的情况。 Thus, the detector detects the reflected light intensity changes in the X-ray refracted by the object.

[0069] 具体地,例如利用数字化摄影技术(DR)通过相位步进技术或莫尔干涉测量法可得出折射角信息。 [0069] Specifically, for example, the use of digital photography (DR) by the phase stepping technique or Moire interferometry refraction angle information can be obtained.

[0070] 需要注意的是,本发明涉及的光栅相衬成像使用的射线源是多色射线源,因此本系统所获得的信息都是平均能量(λ)意义下的折射角信息( [0070] Note that, the present invention relates to a grating phase-contrast imaging using the radiation source is a polychromatic radiation source, the information obtained in this system are the average energy information refraction angle ([lambda]) Significance (

)、一阶相位信息( ), The first order phase information (

)和折射率信息( ) And a refractive index information (

)。 ).

[0071] 为帮助更好地理解本发明,下面分别讨论上述的相位步进(Phasestepping)技术和莫尔干涉测量法(Moire interferometry)。 [0071] To help better understand the present invention, are discussed below in the above-described phase stepping (Phasestepping) and Moire interferometry techniques (Moire interferometry).

[0072] 相位步进技术 [0072] phase stepping technique

[0073] 对于图5所示的系统,两光栅(A、B)相对运动:例如,光栅A固定不动,光栅B沿X方向在光栅周期p2距离范围内平移N(N>1)步(也可以光栅B固定不动,光栅A沿X方向步进)。 [0073] For the system shown in Figure 5, two gratings (A, B) relative movement: for example, A stationary grating, the grating in the X direction B grating period p2 translational distance N (N> 1) Step ( B may be stationary grating, the grating A stepping in the X direction). 光栅B每平移一步,系统采集一次图像;在平移距离范围内采集N张图像后,可获得每个象素(探测器的探测面上的每个点)在一个光栅周期内光强变化曲线的分布情况。 Each step of translating the grating B, a image acquisition system; N after capture images in the translation distance, obtained for each pixel (each point on the detection surface of the detector) of the light intensity curve within a grating period Distribution. 该光强变化函数的形状类似于正弦函数: The shape of the light intensity variation function similar to the sine function:

[0074] [0074]

[0075] 其中A表示振幅,B与光栅周期相关, [0075] where A represents the amplitude, B associated with the grating period,

表示相位。 It represents phase. 举例说明,取塑料模型(见附图8a)内部的某个象素与背景部分的某个象素的光强变化曲线进行比较,见图7(为更好地表现差异,两光栅相对平移了一个半周期)。 Illustration, taking a plastic model (see FIG. 8a) of a light intensity curve of a pixel and the background pixel portion will compare, see FIG. 7 (The better performance differences, the two gratings relative translation a half-cycle). 从图7可发现,当X射线被物体折射后,其光强变化曲线相对于背景的光强变化曲线发生了移动。 It can be found from FIG. 7, when the X-ray refracted by the object, the light intensity curve with respect to the background light intensity curve has moved. 光强变化曲线可用正弦函数来描述,那么光强变化曲线的移动Δf对应着正弦函数的相位变化Δ Light intensity variation curve can be used to describe the sine function, the light intensity variation curve corresponding to a phase change Δf mobile sine function Δ

. 显然,当两光栅相对运动一个周期p2,则正弦函数相位 Clearly, when the two gratings relative movement of one period p2, the phase of the sine function

变化2π,所以有 Changes 2π, so there

[0076] [0076]

[0077] 而Δf是由于X射线被折射引起的,它与折射角的关系是: [0077] and Δf due to X-rays due to refraction, the angle of refraction which relations are:

[0078] Δf=dΔθ (12) [0078] Δf = dΔθ (12)

[0079] 联合式(11)和(12),有 [0079] United formula (11) and (12), there is

[0080] [0080]

[0081] 由此,得到折射角和X射线的相位变化Δ [0081] Accordingly, the phase change and to obtain an X-ray refraction angle Δ

之间的关系,而Δ The relationship between, and Δ

也可以通过比较和计算得出。 It can be drawn by comparing and computing.

[0082] 举例说明在下述实验条件:X射线源的焦点尺寸为170微米,光栅A和光栅B周期分别为20和22微米,源与光栅A距离l为1916.4mm,两光栅距离d为191.6mm,探测器分辨率127微米。 [0082] illustrated in the following experimental conditions: X-ray source focal spot size of 170 microns, the grating period A and B raster 20 and 22 microns, respectively, the source and the grating distance A is l 1916.4mm, two grating distance d is 191.6mm , the detector resolution 127 microns. X射线发射装置设置为高压27kVp,电流9.6mA。 The X-ray emitting means is set to a high-pressure 27kVp, current is 9.6mA. 两光栅相对运动的步长1微米,共步进22步,每步各采集一张投影数据。 Two gratings relative movement in steps of 1 m, a total step 22 steps, each step a for each acquired projection data. 被测物体是直径1厘米的塑料模型(如图8a所示)。 1 cm in diameter measured object is a plastic model (FIG. 8a). 为尽量消除噪声的影响,每张投影图像共采集400张图像进行叠加。 To try to eliminate the influence of noise, each projection images were acquired image 400 superimposed. 最后根据式(13)计算的折射角图像如图8b所示。 The last image refraction angle of formula (13) shown in Figure 8b calculated. 从图8b发现,塑料模型内部的三个孔地结构的边缘清晰地表现出来了。 Found from FIG. 8b, three edges of the internal pore structure of the plastic model clearly shown. 图8c和8d显示了在同样系统条件下测量出来的小老鼠的后爪和尾巴的折射角图像。 FIGS. 8c and 8d shows a rear paw and tail image refraction angle measured under the same system conditions small rodents.

[0083] 莫尔干涉测量法 [0083] Moire interferometry

[0084] 使得光栅A和光栅B基本上平行,但两者相对地旋转一微小角度ε。 [0084] such that the gratings A and B are substantially parallel to the grating, but both are relatively rotated by a slight angle ε. 根据莫尔干涉的原理,当X射线照射到这两块光栅后,在探测器上会观测到莫尔条纹,条纹周期为 The principle of Moire interference, when the X-ray irradiation to these two gratings on the detector will be observed moire fringe period

[0085] [0085]

[0086] 如图9所示。 [0086] as shown in FIG. 可见,ε越小,w越大。 Visible, [epsilon] is, the greater w. 当X射线经物体折射后,其对应的莫尔条纹也将产生相应的形变,设其偏移量为Δf,则折射角可通过式(15)求出: When the X-ray refracted by the object, the corresponding moiré will produce a corresponding strain, provided with an offset of [Delta] f, the refraction angle may be calculated by the formula (15):

[0087] [0087]

[0088] 由此也可以计算得出折射角信息。 [0088] It can also be calculated refraction angle information.

[0089] 综合上述,可以通过两种信息提取技术得到所需的折射角信息。 [0089] The above can be obtained by two kinds of information desired refraction angle information extraction technology.

[0090] 图像显示 [0090] The image display

[0091] 利用前述方法获得的X射线折射角(Δθ)信息,可通过一定的算法,例如线性映射法、查表算法,等得出这个点上的像素信息。 [0091] obtained by the above method of the X-ray refraction angle (Delta] [theta) information by a certain algorithm, such as a linear mapping method, the algorithm look-up table, other pixel information on that point is derived. 例如,可以利用线性映射法计算像素值的公式来实现: For example, the pixel value can be calculated using the linear mapping approach to achieve:

[0092] [0092]

[0093] 其中,z为0-255范围内的像素数值。 [0093] wherein, z is a pixel value in the range 0-255. 这样,X射线经过物体上的每一点所发生的折射角Δθ就可以转化为这一点的像素信息。 Thus, X-rays after refraction angle Δθ occurring every point on the object that can be converted to pixel information. 利用得到的关于物体每一点的像素信息,可以得出物体的图像象素值并在显示器上显示。 Using pixel information obtained at each point on the object, pixel values ​​of the object image can be obtained and displayed on the display.

[0094] CT图像重建 [0094] CT image reconstruction

[0095] 源光栅探测器三者不动,旋转物体;或者物体不动,源光栅探测器三者同时绕物体旋转,均可实现对物体的相衬CT成像。 [0095] The source grating detector three fixed, rotation of the object; or the object does not move, the source grating detector about the object while rotating the three, can achieve the object of the contrast CT imaging.

[0096] 对每一个投影角度φ,均采用相位步进技术或莫尔干涉测量法计算当前投影角度的折射角信息Δθφ: [0096] For each projection angle φ, phase stepping techniques are used to calculate the current or moire interference measurement projection angle refraction angle information Δθφ:

[0097] [0097]

[0098] 其中l表示X射线传播路径。 [0098] wherein l represents the X-ray propagation paths.

[0099] 而传统CT技术的基于线性衰减系数的投影数据表达公式为 [0099] Based on the conventional CT projection data expressing the linear attenuation coefficient of formula

[0100] [0100]

[0101] 其中U表示 [0101] wherein U represents

I和I0分别为出射光强和入射光强。 I and I0 are the outgoing light intensity and incident light intensity. 我们发现,式(17)与式(18)非常类似。 We found a very similar formula (17) and (18). 因此可以借鉴传统CT重建算法来重建物体的折射率n(或相位因子δ)分布。 Reference can be conventional CT reconstruction algorithms to reconstruct a refractive index n (or phase factor [delta]) distribution of an object.

[0102] 如图6所示,本发明的两光栅相衬CT成像系统,根据物体旋转中心轴与光栅平行方向(图1中Z方向)相互关系,可将CT模式分为2种方式:物体旋转中心轴与光栅平行方向互相平行的方式(平行方式,如图6a所示);物体旋转中心轴与光栅平行方向互相垂直的方式(垂直方式,如图6b所示)。 [0102] As shown in FIG. 6, the two phase-contrast grating of the present invention a CT imaging system, the object according to the rotation center axis parallel to the grating direction (Z direction in FIG. 1) relationship, CT mode can be divided into two ways: object rotate the central axis of the grating parallel to the direction parallel to each other (parallel fashion, Figure 6a); the central axis of rotation of the object is perpendicular to the grating direction parallel fashion (vertically, as shown in FIG. 6b). 这两种方式的相衬CT重建公式是不一样的。 Phase contrast CT reconstruction formula of these two methods is not the same.

[0103] 1)平行方式 [0103] 1) a parallel manner

[0104] 在平行模式里,折射角信息Δθψ可看作一个在XOY平面里的矢量,其矢量方向始终垂直于投影方向。 [0104] In the parallel mode, the angle of refraction can be regarded as a Δθψ information in the XOY plane in the vector, which is always perpendicular to the vector direction of the projection direction. 因此,Δθφ的矢量方向会随着投影方向的改变而改变,因此就不能直接使用传统衰减CT的重建算法(μ不随投影方向改变而改变)来计算物体的折射率n(或相位因子δ)断层图像。 Thus, the vector direction will change with Δθφ projection direction is changed, and therefore can not be used directly in the reconstruction algorithm conventional CT attenuation ([mu] without changing the projection direction change over) to calculate the refractive index n (or phase factor [delta]) object faults image. 而因采用针对一阶微分投影数据的CT重建算法,需要使用希耳伯特(Hilbert)滤波器对一阶微分投影数据进行滤波,然后再反投影,重建出折射率n(或相位因子δ)断层图像。 And by using CT reconstruction algorithm for first-order differential projection data required Hilbert (in Hilbert) first-order differential filter for filtering the projection data, and then back projection, to reconstruct the refractive index n (or phase factor [delta]) tomographic image.

[0105] 若射线源和物体之间的距离比较远,且射线源张角较小的情况下,可使用一阶微分投影数据的平行束CT重建公式来近似重建折射率n(或相位因子δ)断层图像: [0105] If the distance between the radiation source and the object relatively far-ray source and an opening angle is small, the parallel-beam CT reconstruction using first-order differential equation to approximate projection data reconstructed refractive index n (or a phase factor δ ) tomographic images:

[0106] [0106]

[0107] 其中式(19)是在频域极坐标系描述。 [0107] wherein formula (19) described in the frequency domain is a polar coordinate system. -jsign(ρ)即是希尔伯特(Hilbert)滤波函数。 -jsign (ρ) is the Hilbert i.e. (in Hilbert) filter function.

是折射角Δθφ在频域极坐标上的表示形式。 Δθφ refraction angle is the frequency domain representation in polar coordinates.

[0108] 当然也可直接采用一阶微分投影数据的扇束CT重建公式重建折射率n(或相位因子δ)断层图像,其重建公式在实数域极坐标描述为 [0108] Of course, can be directly used a fan-beam CT reconstruction order differential equation projection data reconstructed refractive index n (or phase factor [delta]) tomographic image reconstruction formula in polar coordinates which describe the real number domain

[0109] [0109]

[0110] 其中,Θ(φ,s)是折射角Δθφ在实数域极坐标表示。 [0110] where, Θ (φ, s) is represented in refraction angle Δθφ polar real domain. R是源和物体的距离,D是源和探测器的距离,s是探测器上的像素点距离探测器中心的距离,U为反投影权重因子: R is the distance of the source and the object, D is the distance of source and detector, s is the distance from the detector pixels on the detector center, U is backprojection weighting factors:

[0111] [0111]

[0112] 实际上射线源发射出来的是锥束X射线,因此可以直接采用一阶微分投影数据的锥束CT重建公式折射率n(或相位因子δ)断层图像,其重建公式用FDK型表述: [0112] Indeed radiation source is emitted from an X-ray cone beam, and thus can be used directly n (or phase factor [delta]) tomographic image reconstruction of cone beam CT refractive index of first-order differential equation of projection data, which FDK reconstruction type expressed by the formula :

[0113] [0113]

[0114] 其中, [0114] wherein,

[0115] [0115]

[0116] [0116]

[0117] [0117]

[0118] Θφ(Y,Z)表示折射角, [0118] Θφ (Y, Z) represents a refraction angle,

是空间向量所指定的点, Space vector designated point,

是X射线传播方向在xy平面的投影, X-ray projection in the xy plane of the direction of propagation,

是xy平面中和 It is an xy plane, and

垂直的方向,R是射线源和物体间距离,D是射线源和探测器间的距离,Y表示探测器单元的横坐标,Z表示探测器单元的纵坐标。 Vertical direction, R is the distance between the radiation source and the object, D is the distance between the ray source and detector, Y abscissa detector unit, Z represents the ordinate detector unit.

[0119] 2)垂直方式 [0119] 2) in a vertical manner

[0120] 在平行模式里,折射角信息Δθψ可看作一个垂直于在XOY平面的矢量(Z方向),它不随着投影方向改变而改变,因此可以直接采用传统CT里面的平行束,扇束或锥束等重建公式,重建出 [0120] In the parallel mode, the angle of refraction Δθψ information may be considered in a vector perpendicular to the XOY plane (Z direction), which does not change with changes in projecting direction, and therefore can be directly used inside a conventional parallel beam CT, fan beam cone beam reconstruction formula or the like, reconstructed

(或相位因子 (Or phase factor

断层图像。 Tomographic image.

[0121] 需要说明的是,本发明的两光栅相衬成像照相及其CT系统中,被检测物体也可以放置在两个吸收光栅之间,如图11所示,原理如上所述,同样也能获得相衬图像。 [0121] Incidentally, according to the present invention, two grating phase contrast photographing and CT imaging systems, an object to be detected may be placed between the two absorption grating, as shown in FIG. 11, the principle described above, also phase contrast image can be obtained.

[0122] 根据本发明,CT扫描方式可以分为两种,即源和探测器不动,物体自身旋转;或者物体不动,源和探测器绕物体旋转。 [0122] According to the present invention, CT scanning can be divided into two types, i.e., the source and detector do not move, rotating the object itself; or the object does not move, the source and detector rotate about the object. 为实现自动检测的功能,本发明的X射线光栅相衬成像系统进一步包括机械致动系统,受本发明成像系统的控制单元的控制,该机械致动系统包括:旋转装置,用于仅使被检测物体发生相对地旋转。 To perform the functions of the automatic detection, X-ray phase-contrast imaging raster system of the invention further includes a mechanical actuation system, controlled by the control unit of the imaging system of the present invention, the mechanical actuation system comprising: a rotating means for causing only detecting an object occurs rotate relatively. 此时,或者仅有被检测的物体发生旋转,而X射线发射装置-光栅-检测单元保持不动;或者,X射线发射装置-光栅-检测单元旋转装置,而物体保持不动。 At this time, the object to be detected or only rotated, and the X-ray emission device - grating - detecting means remains stationary; Alternatively, the X-ray emission device - grating - detecting means rotating means, while the object remains stationary. 在被检测物体不方便旋转,例如被检测物体过分庞大时,这是尤其方便的。 In the rotation detection object is not convenient, for example when the object to be detected excessively large, which is particularly convenient. 当然,所述物台旋转装置和X射线发射装置-光栅-检测单元旋转装置可以同时存在于该机械控制系统中,或者可以仅采用其中一种装置。 Of course, the rotary stage and the X-ray emission device apparatus - grating - detecting unit rotating means may be present in the machine control system simultaneously, or may be using only one device.

[0123] 现有技术中已经有多种关于像素处理的具体方法,例如拉伸和突出某部分的像素等,本发明在此处可以借鉴使用。 [0123] There are several prior art has been on the specific pixel processing methods, such as drawing a pixel and the protruding portion or the like, the present invention herein may be used for reference. 上述处理过程可以通过计算机来实现,其中可以对获得的投影数据进行处理,包括原始数据处理和显示、折射角信息提取、对折射角投影数据重建出物体图像以及绘制三维立体图像等等,并通过显示器显示出来。 The above-described process may be realized by a computer, which can be obtained by processing the projection data, including raw data processing and display, information extraction refraction angle, the refraction angle projection data of the object image and the reconstructed three-dimensional image rendering, etc., and by The display shows up. 也就是,本申请所涉及的数据处理单元和显示单元可以由计算机实现。 That is, the data processing unit and a display unit according to the present application may be implemented by a computer. 计算机可以是高性能的单个PC,也可以是工作站或机群。 The computer may be a high-performance single PC, it can be a workstation or cluster. 显示器可以是CRT传统显示器也可以是液晶显示器。 The display may be a CRT display may be a conventional liquid crystal display. 另外,检测单元和数据处理及显示单元可以集成在一个设备上。 Further, the detection unit and a data processing and display unit may be integrated in one device.

[0124] 综上所述,利用本发明提供的X射线相衬成像系统,可以实现两种成像模式,即照相成像模式和CT成像模式,其对于被检测的物体可以分别实现平面成像和立体成像。 [0124] As described above, phase-contrast X-ray imaging system provided by the present invention may be implemented both imaging modes, i.e., image forming mode and a CT imaging mode, which can be implemented separately for the stereoscopic imaging plane of the imaging and the object to be detected .

[0125] 实施例1 [0125] Example 1

[0126] 在照相成像模式下,被检测的物体相对地固定,然后采用相位步进技术或莫尔干涉测量法,采集X射线经过物体后的折射角信息,并利用各点的折射角信息对物体进行X射线透视成像,从而获得该物体的平面图像。 [0126] In the image forming mode, the object to be detected is relatively fixed, then the phase stepping technique or using Moire interferometry, information acquired after X-ray refraction angle of the object, and use point information of each of the refraction angle ray fluoroscopic imaging objects X, thereby obtaining an image of the object plane.

[0127] 其中如果使用的探测器是X光胶片或者PI板或者DR探测器设备,可获得两光栅特定相对位置时的物体的透视图像。 [0127] wherein if the detector perspective image of an object using a specific relative position of the X-ray film or plate, or PI DR detector device is obtained when the two gratings. 单个透视图像显示了物体内部各个结构的边界的类似一阶微分的增强效果。 Single fluoroscopic image showing a similar order differential effect of reinforcing the respective structures of the inner boundary of the object. 如果是DR探测器设备,可使用采用相位步进技术或莫尔干涉测量法计算得到物体的折射角图像(相衬图像)。 If DR detector device, may be employed using the phase stepping technique or Moire interferometry image calculated refraction angle (phase contrast image) of the object.

[0128] 实施例2 [0128] Example 2

[0129] 在CT成像模式下,被检测物体应能够相对于系统的其他部分如光栅、射线源转动。 [0129] In the CT imaging mode, the object to be detected with respect to the rest of the system, such as a grating, radiation source is rotated. 所以,为被检测物体设置一种转动装置,用来旋转被检测的物体,或者是设置一种转动结构使得被检测的物体不动而射线源、光栅等相对地旋转。 Therefore, the object to be detected by a rotary means for rotating the object to be detected, or the structure is arranged such that a rotary body to be detected is stationary and the radiation source, grating rotate relatively. 所述的转动装置或转动结构并未在图中示出,其根据已有公知常识可以具有多种实现方式。 Rotating said rotatable structure or device not shown in the figures, based on common general knowledge may have been a variety of implementations. 并且,这样的转动装置或结构与成像系统的控制部分连接,使得转动与系统(步进和其他)动作相适应。 Further, such a rotation control means or part of the structure of the imaging system is connected, so that rotation of the system (and other step) adapted actions. 根据相衬CT成像原理,该利用本发明的系统进行物体的CT成像可以获得对物体的各个投影方向进行X射线平面成像,然后将获得的各方向平面投影数据进行相关的CT重建处理,从而获得被检测物体的折射率的断层图像,或立体图像。 The principle of phase contrast CT imaging, using the system object of the present invention can be obtained CT imaging plane of the imaging X-ray projection direction of each object, and each of the flat projection data obtained were related to the CT reconstruction process, to thereby obtain refractive index detection tomographic image of an object, or stereoscopic image.

[0130] 尽管已经详细描述了本发明,但是本领域技术人员将理解的是,对于目前所给出的公开内容,在不脱离这里所描述的本发明概念的精神范围内可以做出变形。 [0130] While the present invention has been described in detail, those skilled in the art will understand that, for the present disclosure given, within the spirit of scope of the concepts described herein without departing from the present invention can be made deformable. 因此,并不意味着本发明的范围局限于所示出的和所描述的特定实施例。 Thus, specific and does not imply that the scope of the invention described in the illustrated embodiment limited to the embodiment.

Claims (46)

  1. 1.一种X射线光栅相衬成像系统,用于对物体进行透视成像,该系统包括: 1. An X-ray phase-contrast imaging grating system for fluoroscopic imaging of objects, the system comprising:
    X射线发射装置,用于向被检测物体发射X射线束; X-ray emission means for emitting X-ray beams to the object to be detected;
    第一和第二吸收光栅,位于X射线束的发射方向上,用于取得X射线束经过物体的折射角信息; First and second absorption grating, located in the emission direction of the X-ray beam, X-ray beams for acquiring information through the refraction angle of the object;
    检测单元,位于被检测物体和所述第一、第二吸收光栅的后面,用于接收经所述经被检测物体折射的X射线,并将其转换为可识别的电信号;以及 Detecting means located in the object to be detected and the first, second behind the absorption grating, for receiving the said object to be detected by X-ray refraction, and converted into electric signals recognizable; and
    数据处理单元,用于处理所述电信号并从其中计算出X射线束在所述物体的各平面位置处的折射角信息; A data processing unit for processing the electrical signal and wherein the calculated X-ray beam at a refraction angle information in each of said object plane position;
    成像单元,用于重建物体的图像。 Image forming means for reconstructing an image of the object.
  2. 2.如权利要求1的系统,其中,所述X射线装置发射非相干的X射线束,其能量范围在几KeV到几百KeV之间。 2. The system of claim 1, wherein said X-ray device emits incoherent X-ray beam, the energy range between several hundreds of KeV to several KeV.
  3. 3.如权利要求2的系统,其中,该X射线装置包括X射线源,该X射线源的焦点尺寸p0满足: 3. A system as claimed in claim 2, wherein the X-ray apparatus comprising X-ray focus size p0 satisfies source, the X-ray source:
    其中λ为X射线的波长,p0为X射线发射装置的焦点尺寸,p1为所述第一吸收光栅(A)的周期,l为所述第一吸收光栅与所述X射线发射装置的射线源之间的距离。 Wherein λ is the wavelength of X-rays, p0 is the focus size of the X-ray emission device, p1 of the first grating absorption (A) of the cycle, l is the first absorption grating and the X-ray radiation source emitting means the distance between.
  4. 4.如权利要求3的系统,其中,所述X射线源的焦点尺寸不大于所述X射线发射装置的临界焦点尺寸的一半,其中所述X射线发射装置的临界焦点尺寸p0,critical为其中p2为所述第二吸收光栅的周期,d为所述第一吸收光栅与所述第二吸收光栅之间的距离。 4. The system of claim 3, wherein said X-ray source focus size is no more than half the critical focus size of the X-ray emission device, wherein a critical focus size of the X-ray emitting means p0, critical in which p2 is the second period of the absorption grating, d is the first and the second absorbent absorption grating distance between the grating.
  5. 5.如权利要求1的系统,其中,所述X射线发射装置发射锥形的X射线束。 5. The system of claim 1, wherein said X-ray emitting means for emitting a conical X-ray beam.
  6. 6.如权利要求1的系统,其中所述第一和第二吸收光栅(A,B)之间的距离满足方程式其中p1、p2分别为第一、第二光栅的周期,l为所述X射线发射装置与第一吸收光栅之间的距离,d为第一和第二吸收光栅之间的距离。 6. The system of claim 1, wherein a distance between said first and second absorption gratings (A, B) satisfies the equation wherein p1, p2, respectively a first, a second grating period, l is the X ray emission device and a distance between the first absorption grating, d is the distance between the first and second absorption gratings.
  7. 7.如权利要求4的系统,其中X射线源的焦点尺寸大小为10-1000微米。 7. The system of claim 4, wherein the focus of the X-ray source size of 10 to 1000 microns.
  8. 8.如权利要求6的系统,其中所述第一吸收光栅和第二吸收光栅的周期p1、p2在0.1微米-30微米之间。 8. The system of claim 6, wherein said first and second absorption grating period p1 absorption grating, p2 between 0.1 microns to 30 microns.
  9. 9.如权利要求4的系统,其中 9. The system as claimed in claim 4, wherein
    所述X射线发射装置包括多缝准直器,其中所述X射线源的焦点尺寸大于所述X射线发射装置的临界焦点尺寸的一半,所述X射线发射装置的临界焦点尺寸为 The X-ray emission device comprising a multi-slit collimator, wherein the focus size of the X-ray source is greater than half the critical focus size of the X-ray emission device, the X-ray emitting means critical focus size is
    所述多缝准直器的周期ps=Mp0,critical,M=1,2,3,...,放置在所述X射线发射装置与所述第一吸收光栅之间,并且其中所述多缝准直器每条缝的宽度不大于所述X射线发射装置的临界焦点尺寸的一半。 The multi-slit collimator period ps = Mp0, critical, M = 1,2,3, ..., is placed between the X-ray emission means and the first absorption grating, and wherein said plurality each slit collimator slit width no greater than half the X-ray emission means critical focus size.
  10. 10.如权利要求1或8的系统,其中所述第一和第二吸收光栅采用重金属作为吸收材料,所述吸收材料的厚度为10微米-100微米。 10. The system of claim 1 or claim 8, wherein said first and second heavy metal absorption grating as the absorbing material employed, the thickness of the absorbing material is 10 micrometer to 100 micrometers.
  11. 11.如权利要求1的系统,其中所述检测单元包括矩阵结构的探测元,每个探测元用于检测X射线的强度变化并转化为可识别的电信号。 11. The system of claim 1, wherein said detecting means comprises a detecting element matrix structure, each detection element for detecting a change in the intensity of X-rays into electrical signals and recognizable.
  12. 12.如权利要求1的系统,所述数据处理单元通过对所述电信号进行计算得出X射线的光强变化,并利用所述光强变化的值计算得出X射线经过被检测物体的折射角。 12. The system of X-rays through the object to be detected claim, said data processing unit by the electrical signal change in light intensity calculated X-ray, and is calculated using the change in light intensity value derived angle of refraction.
  13. 13.如权利要求12的系统,其中所述数据处理单元通过所述折射角信息,计算得出对于所述被检测物体成像的像素信息。 13. The system of claim 12, wherein said data processing unit through the refraction angle information calculated pixel information with respect to the imaged object is detected.
  14. 14.如权利要求1的系统,其中所述被检测物体位于所述X射线发射装置与所述第一和第二吸收光栅之间。 14. The system of claim 1, wherein said detected object is located between the X-ray emission means and the first and second absorption gratings.
  15. 15.如权利要求1的系统,其中所述第一吸收光栅和第二吸收光栅分别位于被检测物体的两侧。 15. The system of claim 1, wherein said first and second absorption grating absorption grating on each side of the object to be detected.
  16. 16.如权利要求1的系统,其中所述的第一吸收光栅和第二吸收光栅之间具有一个微小角度ε,使得在测量单元的检测面上产生莫尔条纹;由此可以得到在设置被检测物体和未设置被检测物体时在检测面上测量的莫尔条纹变化量;该变化量根据预定的关于所述莫尔条纹变化与折射角之间的关系式,得出X射线经过被检测物体时的折射角信息。 16. The system of claim 1, having a slight angle ε between wherein said first and second absorption grating absorption grating, so that the detection surface of the generation of moire measurement unit; can be obtained by setting and detecting an object change amount detecting moire measurement object on the detection surface is not provided; the amount of change in accordance with a predetermined relationship between on the moire fringes changes the angle of refraction, it is obtained through the X-ray detector angle of refraction information objects.
  17. 17.如权利要求14或15的系统,其中所述第一吸收光栅和第二吸收光栅与一个步进移动装置相连接,使得第一、第二吸收光栅之一不动,而另一吸收光栅在平行于光栅平面的方向上步进动作。 17. The system of claim 14 or claim 15, wherein the first grating and absorption grating is connected to a second absorption step with a mobile device, such that the first and second absorption grating fixed one, while the other absorption grating in a direction parallel to the plane of the grating stepping operation.
  18. 18.一种利用X射线对物体进行相衬成像的方法,该方法包括下述步骤: 18. An X-ray phase contrast imaging of objects, the method comprising the steps of:
    向被检测物体发射X射线束; Transmitting to the object to be detected X-ray beam;
    使经折射的X射线束穿过第一和第二吸收光栅(A,B),从而在检测面上形成强度变化的X射线信号; So that the refracted X-ray beam through the first and second absorption gratings (A, B), thereby forming the X-ray signal intensity variations in the detection plane;
    接收所述强度变化的X射线,将X射线信号转换为可识别的电信号;以及 Receiving said change in intensity X-rays, the X-ray signal into an electrical signal recognizable; and
    从所述可识别的电信号,计算X射线的光强变化,以及利用所述光强变化值计算出X射线的折射角信息; Electrical signals from said identifiable, calculate X-ray intensity variation, and change with the light intensity value information calculated refraction angle of X-rays;
    利用获得的折射角信息,计算得出被折射物体的图像。 Angle of refraction by using the information obtained, the calculated image of the object is refracted.
  19. 19.如权利要求18的方法,其中所述X射线为非相干的X射线,其能量范围在几KeV到几百KeV之间。 19. The method of claim 18, wherein the X-ray non-coherent X-rays, which KeV energy range between a few to hundreds KeV.
  20. 20.如权利要求18或19的方法,其中,所述第一和第二吸收光栅之间的距离满足方程式: 20. A method as claimed in claim 18 or 19, wherein the distance between the first and second absorption grating satisfies the equation:
    其中p1为所述第一吸收光栅的周期,p2为所述第二吸收光栅的周期,d为所述第一吸收光栅与所述第二吸收光栅之间的距离,l为所述第一吸收光栅与X射线发射装置之间的距离。 Wherein p1 is the first absorption grating period, p2 is the second period of the absorption grating, d is the first and the second absorbent absorption grating distance between the grating, l is the first absorption It means the distance between the grating and the X-ray emission.
  21. 21.如权利要求18的方法,其中所述第一吸收光栅和第二吸收光栅的周期在0.1微米-30微米之间。 21. The method of claim 18, wherein said first and second absorption grating absorption grating period is between 0.1 microns to 30 microns.
  22. 22.如权利要求18的方法,其中还包括利用所述折射角信息,计算得出被检测物体的像素信息。 22. The method as claimed in claim 18, further comprising utilizing the refraction angle information calculated pixel information detected object.
  23. 23.如权利要求18的方法,其中使所述被检测物体位于所述X射线发射装置与所述第一和第二吸收光栅之间。 23. The method of claim 18, wherein the detection object is located between the X-ray emitting means and the first and second absorption gratings.
  24. 24.如权利要求18的方法,其中使所述第一吸收光栅和第二吸收光栅分别位于被检测物体的两侧。 24. The method as claimed in claim 18, wherein said first and second absorption grating absorption grating on each side of the object to be detected.
  25. 25.如权利要求18的方法,其中所述第一和第二吸收光栅在成像过程中提取所述X射线经过被检测物体后的折射角信息,其使用了相位步进法或者莫尔干涉法。 25. The method as claimed in claim 18, wherein said first and second absorption grating is extracted through the X-ray refraction angle information of the detected object in the imaging process, which uses a phase-stepping method or moire interferometry .
  26. 26.如权利要求25的方法,其中所述相位步进法包括,第一、第二吸收光栅之一不动,而另一吸收光栅在垂直于光栅缝隙和X射线束的方向上步进动作。 26. The method of claim 25, wherein the phase-stepping method comprises, first, one second absorption grating does not move, while the other absorption grating in a direction perpendicular to the X-ray beam and slit grating stepping operation .
  27. 27.如权利要求26的方法,其中在所述的步进动作过程中,测量X射线在检测面上的光强变化曲线,并且将所取得的光强变化曲线与未放置物体时的背景X射线的光强变化曲线相比较,从而得到光强曲线的移动量,根据预定的关于光强曲线移动量和折射角之间的关系式得出折射角信息。 27. The method of claim 26, wherein in said step operation measured during the X-ray intensity curve in the optical detection surface, and the light intensity curve obtained when the background object is not placed X ray intensity curve is compared to obtain the amount of movement of the light intensity curve, obtained in accordance with a predetermined refraction angle information about the relationship between light intensity and amount of movement of the refraction angle of the curve.
  28. 28.如权利要求25的方法,其中所述莫尔干涉法包括: 28. The method as claimed in claim 25, wherein said moire interferometer comprising:
    所述的第一吸收光栅和第二吸收光栅之间具有一个微小角度ε;测量在设置被检测物体和未设置被检测物体时在检测面上测量的莫尔条纹变化量;根据预定的关于所述莫尔条纹变化与折射角之间的关系式,得出X射线经过被检测物体时的折射角信息。 Having a slight angle ε between the first and second absorption grating absorption grating; measuring object to be detected and measured moire amount detection surface changes when the object to be detected is not set in the setting; on the basis of a predetermined the relationship between said moire changes in refraction angle, the refraction angle obtained X-ray information through the object to be detected.
  29. 29.一种X射线光栅相衬CT成像系统,用于对物体进行CT成像,该系统包括: X-ray phase-contrast grating 29. A CT imaging system, a CT image for an object, the system comprising:
    X射线发射装置,用于向被检测物体发射X射线束; X-ray emission means for emitting X-ray beams to the object to be detected;
    第一和第二吸收光栅,位于X射线束的发射方向上,操作用于取得X射线束经过物体的折射角信息; First and second absorption grating, located in the emission direction of the X-ray beam, an operation for obtaining X-ray beam after refraction angle information of the object;
    检测单元,位于被检测物体和所述第一、第二吸收光栅的后面,用于接收经所述经被检测物体折射的X射线,并将其转换为可识别的电信号;以及 Detecting means located in the object to be detected and the first, second behind the absorption grating, for receiving the said object to be detected by X-ray refraction, and converted into electric signals recognizable; and
    数据处理单元,用于处理所述电信号并从其中计算出X射线在所述物体的各平面位置处的折射角信息; A data processing unit for processing the electrical signal and wherein the calculated refraction angle of X-ray information in the object plane of the respective positions;
    转动装置,其操作用于使得被检测的物体相对于系统的其他部分转动; Rotating means operable such that the detected object relative to other portions of the system of rotation;
    成像单元,通过利用折射角信息重建物体的CT图像。 An imaging unit CT reconstructed image of the object by using refraction angle information.
  30. 30.如权利要求29的系统,其中所述X射线发射装置发射非相干的X射线,其能量范围在几KeV到几百KeV之间。 30. The system as claimed in claim 29, wherein said X-ray emitting means for emitting a non-coherent X-rays, which KeV energy range between a few to hundreds KeV.
  31. 31.如权利要求29的系统,包括一个控制单元,该控制单元与所述转动装置相连接,用于控制所述被检测物体相对地转动。 31. The system as claimed in claim 29, comprising a control unit, which control unit is connected to said rotation means for controlling the detected object relatively rotated.
  32. 32.如权利要求29-31中任一所述的系统,其中 The system according to any one of claims 29-31 32., wherein
    所述的第一吸收光栅和第二吸收光栅之间具有一个微小角度ε,使得在所述测量单元的检测面上产生莫尔条纹; Between the first absorption grating and absorption grating having a second slight angle ε, such that moire fringes on the detection surface of the measuring unit;
    其中通过比较在设置被检测物体和未设置被检测物体时在检测面上测量的莫尔条纹,得到莫尔条纹的变化量; Wherein by comparing the detected object is provided and not provided on the detection surface to be measured of the object detecting moire obtained variation amount of moiré;
    由该莫尔条纹变化量,所述数据处理单元根据预定的关于所述莫尔条纹变化与折射角之间的关系式,得出X射线经过被检测物体时的折射角信息。 The moire fringes by the change amount according to the data processing unit on a predetermined relationship between changes in the Moire fringes and the refraction angle, the refraction angle obtained through the X-ray information of the detected object.
  33. 33.如权利要求29-31中任一所述的系统,其中所述第一吸收光栅和第二吸收光栅与一个步进移动装置相连接,该步进移动装置使得第一、第二吸收光栅之一不动,而另一吸收光栅在垂直于光栅缝隙和X射线束的方向上在被移动光栅的一个周期范围内步进动作,由此得出X射线在所述检测单元的检测面上的光强曲线; 33. The system of any one of claim 29-31 wherein said first grating and absorption grating is connected to a second absorption step a mobile device, the mobile device such that a first step, a second absorption grating one does not move, while the other absorption grating in a direction perpendicular to the grating and the X-ray slit beam range is within a period of the moving grating stepping operation, it follows that the detection surface of the X-ray detection unit light intensity curve;
    通过比较在设置被检测物体和未设置被检测物体时的所述X射线光强曲线,可得出X射线光强曲线的移动量; And the object to be detected is not provided when the detected X-ray intensity curve of the object by comparing the set amount of movement of the X-ray intensity curve can be drawn;
    根据关于所述光强曲线移动量和X射线经过被检测物体时的折射角之间的关系式,得出所述折射角信息。 The refraction angle according to information regarding the amount of movement of the light intensity curve and the relationship between the X-ray after refraction angle when the object to be detected, obtained.
  34. 34.如权利要求33的系统,其中控制单元还控制所述步进移动装置相连接,用于控制它的步进动作。 34. The system as claimed in claim 33, wherein the control unit further controls the stepping movement device connected to it for controlling the stepping operation.
  35. 35.如权利要求29的系统,其中所述的转动装置在控制下使得被检测的物体在完成一次X射线的扫描成像后,转动一定的角度;然后系统重复X射线束的扫描成像。 35. The system of claim 29, wherein said rotating means such that the object to be detected under control after the completion of a X-ray scan imaging, a certain rotation angle; scanning imaging system then repeats the X-ray beam.
  36. 36.如权利要求29的系统,其中通过预定的CT重构算法利用获得的平面图像数据来实现重构物体内部的折射率分布的断层图像。 36. The system as claimed in claim 29, wherein the plane image data obtained by a predetermined algorithm using the CT tomographic image reconstruction to achieve the refractive index distribution inside the reconstructed object.
  37. 37.一种X射线光栅相衬CT成像方法,用于对物体进行CT成像,该系统包括: An X-ray phase-contrast grating 37. A CT imaging method for CT imaging of objects, the system comprising:
    向被检测物体发射X射线束; Transmitting to the object to be detected X-ray beam;
    使经折射的X射线束穿过第一和第二吸收光栅(A,B),从而在检测面上形成强度变化的X射线信号; So that the refracted X-ray beam through the first and second absorption gratings (A, B), thereby forming the X-ray signal intensity variations in the detection plane;
    接收所述强度变化的X射线,将X射线信号转换为可识别的电信号; Receiving said change in intensity X-rays, the X-ray signal into electrical signals can be identified;
    从所述可识别的电信号,计算X射线的光强变化,以及利用所述光强变化值计算出X射线的折射角信息; Electrical signals from said identifiable, calculate X-ray intensity variation, and change with the light intensity value information calculated refraction angle of X-rays;
    利用获得的折射角信息,计算得出被折射物体的平面图像; Angle of refraction by using the information obtained, calculated refracted image of the object plane;
    转动被检测物体,重复上述步骤,并对获得的多个平面图像进行处理从而获得该被检测物体的CT图像。 Rotation of the object to be detected, repeating the above steps, a plurality of planar images obtained and processed to obtain a CT image of the detected object.
  38. 38.如权利要求37的方法,其中所述X射线为非相干的X射线,其能量范围在几KeV到几百KeV之间。 38. The method as claimed in claim 37, wherein the X-ray non-coherent X-rays, which KeV energy range between a few to hundreds KeV.
  39. 39.如权利要求37的方法,其中,所述第一和第二吸收光栅之间的距离满足方程式: 39. The method of claim 37, wherein the distance between the first and second absorption gratings satisfy the equation:
    其中p1为所述第一吸收光栅的周期,p2为所述第二吸收光栅的周期,d为所述第一吸收光栅与所述第二吸收光栅之间的距离,l为所述第一吸收光栅与X射线发射装置之间的距离。 Wherein p1 is the first absorption grating period, p2 is the second period of the absorption grating, d is the first and the second absorbent absorption grating distance between the grating, l is the first absorption It means the distance between the grating and the X-ray emission.
  40. 40.如权利要求37的方法,其中还包括利用所述折射角信息,根据预定的算法计算得出被检测物体的像素信息。 40. The method of claim 37, further comprising utilizing the refraction angle information obtained pixel information of the detected object in accordance with a predetermined calculation algorithm.
  41. 41.如权利要求37的方法,其中所述第一和第二吸收光栅在成像过程中提取所述X射线经过被检测物体后的折射角信息,使用了相位步进法或者莫尔干涉法。 41. The method as claimed in claim 37, wherein said first and second absorption grating extracted refraction angle of the X-ray information through the object to be detected using the phase-stepping method or moire interferometry during imaging.
  42. 42.如权利要求41的方法,其中所述相位步进法包括,第一、第二吸收光栅之一不动,而另一吸收光栅在垂直于光栅缝隙的方向上步进动作。 42. The method as claimed in claim 41, wherein the phase-stepping method comprises, first, one second absorption grating does not move, while the other absorption grating in a direction perpendicular to the grating slits stepping operation.
  43. 43.如权利要求41的方法,其中在所述的步进动作过程中,测量X射线在检测面上的光强变化曲线,并且将所取得的光强变化曲线与未放置物体时的背景X射线的光强变化曲线相比较,从而得到光强曲线的移动量,根据预定的关于光强曲线移动量和折射角之间的关系式得出折射角信息。 43. The method of claim 41, wherein during the step operation, the measured X-ray intensity curve in the optical detection surface, and the light intensity curve obtained when the background object is not placed X ray intensity curve is compared to obtain the amount of movement of the light intensity curve, obtained in accordance with a predetermined refraction angle information about the relationship between light intensity and amount of movement of the refraction angle of the curve.
  44. 44.如权利要求41的方法,其中所述莫尔干涉法包括: 44. The method as claimed in claim 41, wherein said moire interferometer comprising:
    使得所述的第一吸收光栅和第二吸收光栅之间具有一个微小角度ε;测量在设置被检测物体和未设置被检测物体时在检测面上测量的莫尔条纹变化量;根据预定的关于所述莫尔条纹变化与折射角之间的关系式,得出X射线经过被检测物体时的折射角信息。 Having such a slight angle ε between the first and second absorption gratings absorption grating; measuring a detected object is provided and not provided on the detection surface to be measured when detecting an object change amount moire fringes; on according to a predetermined the relationship between the moire fringes and the angle of refraction changes, the refraction angle is obtained through the X-ray information of the detected object.
  45. 45.如权利要求37的方法,其中在射线源为大焦点光源的情况下,添加一个多缝准直器,其优选为源光栅,来产生一组小焦点线光源以向被检测物体发射X射线束。 45. The method of claim 37, wherein in the case where the radiation source is a major focus of the light source, adding a multi-slit collimator, which is preferably a source grating to produce a set of small linear light sources to focus the object to be detected emitted X ray beam.
  46. 46.如权利要求37的方法,其中,所述X射线束为平行束、扇束和锥束形式之一。 46. ​​The method as claimed in claim 37, wherein the X-ray beam is a parallel beam, fan beam and cone-beam one form.
CN 200810166472 2007-11-23 2008-10-09 System and method for phase-contrast imaging by use of X-ray gratings CN101532969B (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
CN200710178014 2007-11-23
CN200710178014.2 2007-11-23
CN 200810166472 CN101532969B (en) 2007-11-23 2008-10-09 System and method for phase-contrast imaging by use of X-ray gratings

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN 200810166472 CN101532969B (en) 2007-11-23 2008-10-09 System and method for phase-contrast imaging by use of X-ray gratings

Publications (2)

Publication Number Publication Date
CN101532969A true true CN101532969A (en) 2009-09-16
CN101532969B CN101532969B (en) 2013-04-17

Family

ID=41103699

Family Applications (2)

Application Number Title Priority Date Filing Date
CN 200810005766 CN101576515B (en) 2007-11-23 2008-02-04 System and method for X-ray optical grating contrast imaging
CN 200810166472 CN101532969B (en) 2007-11-23 2008-10-09 System and method for phase-contrast imaging by use of X-ray gratings

Family Applications Before (1)

Application Number Title Priority Date Filing Date
CN 200810005766 CN101576515B (en) 2007-11-23 2008-02-04 System and method for X-ray optical grating contrast imaging

Country Status (1)

Country Link
CN (2) CN101576515B (en)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011130896A1 (en) * 2010-04-19 2011-10-27 清华大学 X ray source grating stepping imaging system and image method
CN102579066A (en) * 2012-02-17 2012-07-18 天津大学 X-ray coaxial phase-contrast imaging method
CN102655809A (en) * 2009-12-10 2012-09-05 皇家飞利浦电子股份有限公司 Apparatus for phase-contrast imaging comprising a displaceable X-ray detector element and method
CN102656644A (en) * 2009-12-10 2012-09-05 皇家飞利浦电子股份有限公司 Non-parallel grating arrangement with on-the-fly phase stepping, X-ray system and use
CN102781327A (en) * 2009-12-10 2012-11-14 皇家飞利浦电子股份有限公司 Phase contrast imaging
CN103068311A (en) * 2010-08-19 2013-04-24 富士胶片株式会社 Radiography system and image-processing method therefor
CN103365068A (en) * 2012-04-01 2013-10-23 中国科学院高能物理研究所 Grating shearing three-dimensional imaging system and grating shearing three dimensional imaging method
US9001969B2 (en) 2010-02-04 2015-04-07 Fujifilm Corporation Radiation imaging system
CN104516010A (en) * 2014-12-31 2015-04-15 清华大学 X-ray beam intensity monitoring device and X-ray inspection system
CN104582573A (en) * 2012-08-20 2015-04-29 皇家飞利浦有限公司 Aligning source-grating-to-phase-grating distance for multiple order phase tuning in differential phase contrast imaging
WO2015058702A1 (en) 2013-10-23 2015-04-30 曹红光 Photon count-based radiation imaging system, method, and apparatus
WO2015066977A1 (en) * 2013-11-11 2015-05-14 中国科学技术大学 Apparatus and method for x-ray grating phase-contrast imaging
CN105228524A (en) * 2013-05-22 2016-01-06 西门子股份公司 Phase-contrast x-ray imaging device
RU2572644C2 (en) * 2010-10-19 2016-01-20 Конинклейке Филипс Электроникс Н.В. Differential phase-contrast imaging
RU2573114C2 (en) * 2010-10-19 2016-01-20 Конинклейке Филипс Электроникс Н.В. Image forming by differential phase contrast
WO2016070739A1 (en) 2014-11-04 2016-05-12 同方威视技术股份有限公司 Multi-energy spectrum x-ray grating imaging system and imaging method
WO2016070771A1 (en) 2014-11-04 2016-05-12 清华大学 X-ray phase-contrast imaging system and imaging method
CN105612584A (en) * 2013-10-07 2016-05-25 西门子医疗有限公司 Phase contrast X-ray imaging device and phase grating therefor
CN105931292A (en) * 2016-06-13 2016-09-07 南京理工大学 Multidirectional Moire chromatography method based on affine calibration
CN106153646A (en) * 2015-04-08 2016-11-23 清华大学 X ray imaging system and method

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9297772B2 (en) 2013-07-30 2016-03-29 Industrial Technology Research Institute Apparatus for amplifying intensity during transmission small angle—X-ray scattering measurements

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006063048B3 (en) 2006-02-01 2018-03-29 Siemens Healthcare Gmbh Focus / detector system of an X-ray apparatus for generating phase contrast images
CN101011253B (en) 2006-02-01 2011-06-15 保罗谢勒研究所 Focus-detector arrangement for generating projective or tomographic phase contrast recordings

Cited By (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102655809A (en) * 2009-12-10 2012-09-05 皇家飞利浦电子股份有限公司 Apparatus for phase-contrast imaging comprising a displaceable X-ray detector element and method
CN102656644A (en) * 2009-12-10 2012-09-05 皇家飞利浦电子股份有限公司 Non-parallel grating arrangement with on-the-fly phase stepping, X-ray system and use
CN102781327A (en) * 2009-12-10 2012-11-14 皇家飞利浦电子股份有限公司 Phase contrast imaging
CN102656644B (en) * 2009-12-10 2016-11-16 皇家飞利浦电子股份有限公司 Means a non-parallel grating having a phase stepping instant, x-ray system and the use of
RU2545319C2 (en) * 2009-12-10 2015-03-27 Конинклейке Филипс Электроникс Н.В. Phase-contrast image formation
US9001969B2 (en) 2010-02-04 2015-04-07 Fujifilm Corporation Radiation imaging system
US9134259B2 (en) 2010-04-19 2015-09-15 Tsinghua University X-ray source grating stepping imaging system and image method
DE112010005498T5 (en) 2010-04-19 2013-02-07 Tsinghua University Step lattice imaging system with X-ray radiation source and imaging techniques
JP2013524897A (en) * 2010-04-19 2013-06-20 清華大学 Step imaging system and an imaging method for X-ray source grating
WO2011130896A1 (en) * 2010-04-19 2011-10-27 清华大学 X ray source grating stepping imaging system and image method
CN103068311A (en) * 2010-08-19 2013-04-24 富士胶片株式会社 Radiography system and image-processing method therefor
RU2573114C2 (en) * 2010-10-19 2016-01-20 Конинклейке Филипс Электроникс Н.В. Image forming by differential phase contrast
RU2572644C2 (en) * 2010-10-19 2016-01-20 Конинклейке Филипс Электроникс Н.В. Differential phase-contrast imaging
CN102579066A (en) * 2012-02-17 2012-07-18 天津大学 X-ray coaxial phase-contrast imaging method
CN103365068B (en) * 2012-04-01 2016-03-09 中国科学院高能物理研究所 Shearing grating and three-dimensional imaging system three-dimensional imaging method of shearing grating
CN103365067B (en) * 2012-04-01 2016-12-28 中国科学院高能物理研究所 Raster image forming apparatus and method for cutting may be three-dimensional dynamic observation
CN103365067A (en) * 2012-04-01 2013-10-23 中国科学院高能物理研究所 Grating shearing imaging device and method capable of realizing three-dimensional dynamic observation
CN103365068A (en) * 2012-04-01 2013-10-23 中国科学院高能物理研究所 Grating shearing three-dimensional imaging system and grating shearing three dimensional imaging method
RU2631183C2 (en) * 2012-08-20 2017-09-19 Конинклейке Филипс Н.В. Adjustment of distance from source lattice to phase lattice for multiple order phase settings in differential phase-contrast imaging
CN104582573A (en) * 2012-08-20 2015-04-29 皇家飞利浦有限公司 Aligning source-grating-to-phase-grating distance for multiple order phase tuning in differential phase contrast imaging
CN104582573B (en) * 2012-08-20 2018-09-28 皇家飞利浦有限公司 The differential phase-contrast imaging source grating aligned in distance to the multi-stage phase grating for phase tuning
CN105228524A (en) * 2013-05-22 2016-01-06 西门子股份公司 Phase-contrast x-ray imaging device
CN105612584A (en) * 2013-10-07 2016-05-25 西门子医疗有限公司 Phase contrast X-ray imaging device and phase grating therefor
WO2015058702A1 (en) 2013-10-23 2015-04-30 曹红光 Photon count-based radiation imaging system, method, and apparatus
CN104622492A (en) * 2013-11-11 2015-05-20 中国科学技术大学 X-ray grating phase-contrast imaging device and method
WO2015066977A1 (en) * 2013-11-11 2015-05-14 中国科学技术大学 Apparatus and method for x-ray grating phase-contrast imaging
WO2016070739A1 (en) 2014-11-04 2016-05-12 同方威视技术股份有限公司 Multi-energy spectrum x-ray grating imaging system and imaging method
CN105628718A (en) * 2014-11-04 2016-06-01 同方威视技术股份有限公司 Multi-energy-spectrum X-ray grating imaging system and imaging method
WO2016070771A1 (en) 2014-11-04 2016-05-12 清华大学 X-ray phase-contrast imaging system and imaging method
EP3059579A4 (en) * 2014-11-04 2017-08-02 Nuctech Company Limited Multi-energy spectrum x-ray grating imaging system and imaging method
CN104516010A (en) * 2014-12-31 2015-04-15 清华大学 X-ray beam intensity monitoring device and X-ray inspection system
CN106153646A (en) * 2015-04-08 2016-11-23 清华大学 X ray imaging system and method
CN105931292A (en) * 2016-06-13 2016-09-07 南京理工大学 Multidirectional Moire chromatography method based on affine calibration

Also Published As

Publication number Publication date Type
CN101576515B (en) 2012-07-04 grant
CN101576515A (en) 2009-11-11 application
CN101532969B (en) 2013-04-17 grant

Similar Documents

Publication Publication Date Title
Mayo et al. X-ray phase-contrast microscopy and microtomography
US6504892B1 (en) System and method for cone beam volume computed tomography using circle-plus-multiple-arc orbit
US7522698B2 (en) Focus/detector system of an X-ray apparatus for generating phase contrast recordings
US6345194B1 (en) Enhanced high resolution breast imaging device and method utilizing non-ionizing radiation of narrow spectral bandwidth
US7924973B2 (en) Interferometer device and method
Chapman et al. Diffraction enhanced x-ray imaging
Momose et al. Phase tomography by X-ray Talbot interferometry for biological imaging
Momose et al. Phase‐contrast radiographs of nonstained rat cerebellar specimen
Yagi et al. Refraction‐enhanced x‐ray imaging of mouse lung using synchrotron radiation source
US7433444B2 (en) Focus-detector arrangement of an X-ray apparatus for generating projective or tomographic phase contrast recordings
Herzen et al. Quantitative phase-contrast tomography of a liquid phantom using a conventional x-ray tube source
US7693256B2 (en) Phase-contrast X-ray imaging
US7564941B2 (en) Focus-detector arrangement for generating projective or tomographic phase contrast recordings with X-ray optical gratings
US7945018B2 (en) Method for producing projective and tomographic images using an X-ray system
US7983381B2 (en) X-ray CT system for x-ray phase contrast and/or x-ray dark field imaging
US5818901A (en) Medical examination apparatus for simultaneously obtaining an MR image and an X-ray exposure of a subject
Zhou et al. Development of phase-contrast X-ray imaging techniques and potential medical applications
Stutman et al. Talbot phase-contrast x-ray imaging for the small joints of the hand
WO2004058070A1 (en) X-ray imaging system and imaging method
Momose et al. Four-dimensional X-ray phase tomography with Talbot interferometry and white synchrotron radiation: dynamic observation of a living worm
US20120099702A1 (en) Correction method for differential phase contrast imaging
Wen et al. Spatial harmonic imaging of X-ray scattering--initial results
JP2008545981A (en) Interferometer for quantitative phase contrast imaging and tomography with incoherent polychromatic x-ray source
Huang et al. Alternative method for differential phase-contrast imaging with weakly coherent hard x rays
US20010038680A1 (en) X-ray phase-contrast medical micro-imaging methods

Legal Events

Date Code Title Description
C06 Publication
C10 Entry into substantive examination
REG Reference to a national code

Ref country code: HK

Ref legal event code: DE

Ref document number: 1137510

Country of ref document: HK

C14 Grant of patent or utility model
REG Reference to a national code

Ref country code: HK

Ref legal event code: GR

Ref document number: 1137510

Country of ref document: HK