WO2015035867A1 - 旋转光栅锥形束ct - Google Patents

旋转光栅锥形束ct Download PDF

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WO2015035867A1
WO2015035867A1 PCT/CN2014/085759 CN2014085759W WO2015035867A1 WO 2015035867 A1 WO2015035867 A1 WO 2015035867A1 CN 2014085759 W CN2014085759 W CN 2014085759W WO 2015035867 A1 WO2015035867 A1 WO 2015035867A1
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image
grating
frame
ray source
rotating grating
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PCT/CN2014/085759
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English (en)
French (fr)
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梁月强
李宝生
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Liang Yueqiang
Li Baosheng
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Publication of WO2015035867A1 publication Critical patent/WO2015035867A1/zh
Priority to US15/017,631 priority Critical patent/US10105113B2/en

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/40—Arrangements for generating radiation specially adapted for radiation diagnosis
    • A61B6/4035—Arrangements for generating radiation specially adapted for radiation diagnosis the source being combined with a filter or grating
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/02—Arrangements for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
    • A61B6/03—Computed tomography [CT]
    • A61B6/032—Transmission computed tomography [CT]
    • A61B6/035—Mechanical aspects of CT
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/40—Arrangements for generating radiation specially adapted for radiation diagnosis
    • A61B6/4064—Arrangements for generating radiation specially adapted for radiation diagnosis specially adapted for producing a particular type of beam
    • A61B6/4085—Cone-beams
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/52—Devices using data or image processing specially adapted for radiation diagnosis
    • A61B6/5205—Devices using data or image processing specially adapted for radiation diagnosis involving processing of raw data to produce diagnostic data
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/52—Devices using data or image processing specially adapted for radiation diagnosis
    • A61B6/5258—Devices using data or image processing specially adapted for radiation diagnosis involving detection or reduction of artifacts or noise
    • A61B6/5282—Devices using data or image processing specially adapted for radiation diagnosis involving detection or reduction of artifacts or noise due to scatter
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/54—Control of apparatus or devices for radiation diagnosis
    • A61B6/547—Control of apparatus or devices for radiation diagnosis involving tracking of position of the device or parts of the device
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/02—Arrangements for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
    • A61B6/03—Computed tomography [CT]
    • A61B6/032—Transmission computed tomography [CT]
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/40—Arrangements for generating radiation specially adapted for radiation diagnosis
    • A61B6/4064—Arrangements for generating radiation specially adapted for radiation diagnosis specially adapted for producing a particular type of beam
    • A61B6/4078—Fan-beams
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/44—Constructional features of apparatus for radiation diagnosis
    • A61B6/4429—Constructional features of apparatus for radiation diagnosis related to the mounting of source units and detector units
    • A61B6/4435—Constructional features of apparatus for radiation diagnosis related to the mounting of source units and detector units the source unit and the detector unit being coupled by a rigid structure
    • A61B6/4441—Constructional features of apparatus for radiation diagnosis related to the mounting of source units and detector units the source unit and the detector unit being coupled by a rigid structure the rigid structure being a C-arm or U-arm

Definitions

  • cone beam CT has been widely used in stomatology and tumor radiotherapy, and has the advantages of an open structure and convenient use.
  • fan beam CT there is still a disadvantage that the image density information is inaccurate.
  • the influence of the scattered photons on the projected image is the main reason for the inaccuracy of the fan beam CT image density.
  • the physical method For example, a limiting device is used to limit the range of the cone beam. Since the cone angle of the cone beam CT is smaller, the composition of the scattered photons in the projected image is also less. However, limiting the extent of the cone beam also limits the range of imaging. This method does not work for larger imaging targets.
  • Another physical method is to add an anti-scatter grid between the imaging target and the flat panel detector.
  • the backscattering grid can suppress scattered photons in the projected image, it also introduces noise, which is better for the case where the imaging target to the detector has a small distance.
  • the imaging target to detector distance is large (such as cone beam CT integrated into the accelerator used in image guided radiotherapy)
  • the effect of adding a backscatter grid is limited.
  • Another type of method is the post-processing method after projection image acquisition. For example, using the Monte Carlo algorithm, the distribution of scattered photons in the projected image can be accurately estimated. The effect of scattered photons is thus subtracted from the projected image, but even with some simplified computational techniques, the large computational amount of the Monte Carlo algorithm makes it impossible to produce high-resolution scattering distributions in a clinically acceptable time.
  • the analytical model is used to calculate the distribution of scattered photons. Although it has a fast calculation speed, it will produce large calculation deviation for complex imaging targets.
  • the noise suppression reconstruction algorithm can reduce the influence of the scattered photons in the projected image as noise when reconstructing the image.
  • a rotating grating cone beam CT imaging device that uses a grating to limit the X-rays emitted by a source to a plurality of narrow-angle cone beams or fan beams, and then move the narrow-angle cone beam or fan beam through the rotation of the grating. The position of the projection image of different regions of the imaging target is obtained, thereby greatly reducing the influence of scattered photons on the image quality.
  • the imaging device consists of a rack and its drive, a gantry angle sensor, an X-ray source equipped with a rotating grating, a flat panel detector, a main controller and an image reconstruction workstation.
  • the gantry drive drives the gantry to rotate around the imaging target during image acquisition.
  • An X-ray source equipped with a rotating grating and a flat panel detector are mounted on the frame and can be rotated together with the rack.
  • the X-ray source equipped with the rotating grating is composed of an X-ray source, a rotating grating driving device, a grating angle sensor and a rotating grating.
  • the rotating grating limits the X-rays emitted from the ray source to a plurality of narrow-angle cone beams or fan beams, and the grating gap positions at different rotation angles are different, so that the narrow-angle cone of the transmission grating can be changed when the rotating grating rotates.
  • the X-ray source equipped with the rotating grating rotates while the random frame rotates, and the rotating grating also rotates around the X-ray source to scan the projected image of the narrow-angle cone beam or the fan beam transmitted through the grating.
  • the entire flat panel detector to capture projection information of the entire volume image.
  • the projected image is not obtained by a cone beam projection, but is obtained by continuously reciprocating scanning of a plurality of narrow cone beams, which can remove more scattered lines and reduce the scattered photon pair projection.
  • the effect of the image is thus reconstructed into a high-resolution CT image.
  • the rotating grating angle sensor detects the rotation angle of the grating in real time and transmits the angle information to the main controller.
  • the main controller is used to synchronize the raster rotation and image acquisition of the flat panel detector.
  • the rack angle sensor detects the rotation angle of the rack in real time and transmits the angle information to the main controller.
  • main controller Record the gantry angle at the time of each projection image acquisition.
  • the acquired projection image, which is occluded by the grating is considered to be a scatter signal, and the portion not occluded by the grating is considered to be a superposition of the main X-ray signal and the scatter signal.
  • an interpolation algorithm such as cubic spline interpolation
  • the scattered signal that is not occluded by the grating can be estimated by the scatter signal of the occlusion portion of the grating.
  • the projection signal of the main X-ray can be obtained without subtracting the estimated scatter signal from the projection signal of the occlusion portion of the grating.
  • the image reconstruction workstation reconstructs the three-dimensional volume image by using the main X-ray projection signal, the corresponding gantry angle acquired from the main controller, and the FDK reconstruction algorithm, the compressed sensing reconstruction algorithm or the iterative optimization reconstruction algorithm.
  • the image forming apparatus can suppress the advantage of scattering photons to produce high-quality images by rotating a grating, that is, using a narrow cone beam or a fan beam, and obtain an open structure of the cone beam CT imaging apparatus.
  • Figure 1 is a schematic diagram of data communication between parts of Embodiment 1
  • FIG. 3 Schematic diagram of the operation of the rotating grating of Embodiment 1
  • Figure 1 illustrates an embodiment of a rotating grating cone beam CT imaging apparatus.
  • 101 in Fig. 1 is an X-ray source with a rotating grating that changes the position of the X-beam transmitted through the grating as the grating rotates.
  • 106 is a rotating grating of tungsten alloy material
  • 113 is a grating angle sensor
  • 114 is a rotating grating driving device.
  • the rotating grating limits the rays generated in the X-ray source to a plurality of narrow-angle cone beams.
  • 102 is a flat panel detector
  • 105 is an image reconstruction workstation
  • 107 is an image acquisition card mounted on an image reconstruction workstation.
  • 103 is the main controller.
  • the main controller drives the frame and grating rotation through the gantry drive and the rotary encoder drive.
  • the main controller acquires the angular signals of the gantry and the grating through the gantry angle sensor 104 and the grating angle sensor 113.
  • the main controller is also used to synchronize the X-ray source beam, the rotation of the grating and the projection signal acquisition of the flat panel detector. Its working process is:
  • the image reconstruction workstation sends a start image acquisition command to the main controller.
  • the main controller drives the grating to rotate at an angular velocity of 6 revolutions per second by rotating the grating drive.
  • the main controller drives the frame through the rack drive to rotate at an angular velocity of 6 degrees per second.
  • the main controller detects the grating rotation by the grating angle sensor, and sends a control signal to the flat panel detector when a new set of gratings enters between the X-ray source and the imaging target, and clears the image data of the flat panel detector.
  • the main controller sends a control signal to the X-ray source to cause the X-ray source to emerge.
  • the main controller reads the exposure start frame angle from the gantry angle sensor.
  • the image reconstruction workstation After the specified time of exposure, the image reconstruction workstation reads the image data of the flat panel detector through the image acquisition card.
  • the main controller sends a control signal to the X-ray source to stop the X-ray source from exiting.
  • the main controller reads the exposure end rack angle.
  • step d repeat the cycle according to steps d) e) f) g) h) i) until the frame completes a 360 degree rotation.
  • the image reconstruction workstation first preprocesses the projected image read from the detector, and uses the cubic spline interpolation algorithm to estimate the scattered signal without the occlusion portion of the grating by using the scatter signal of the occlusion portion of the grating, and the estimated scatter signal is never The projection image of the raster occlusion portion is removed.
  • the image reconstruction workstation reconstructs the three-dimensional volume image by using a compressed sensing reconstruction algorithm by using a projection image from which the scattered signal is removed, a gantry angle corresponding to the projected image acquired from the main controller.
  • the signal 108 in FIG. 1 is a control signal and response sent by the main controller to the X-ray source with the rotating grating; the signal 109 is the control signal and response sent by the main controller to the flat panel detector; the signal 110 is sent by the image reconstruction workstation.
  • the grating is a tungsten alloy material, and a set of gratings every 60 degrees, a total of six sets of gratings, which are 201, 202, 203, 204, 205, and 206 in order.
  • Each set of gratings consists of 6 slits, each slit is 3 mm wide, and the center of adjacent slits in the same group is 12 mm apart. Starting from 201, the latter set of grating gaps are offset from the previous set of grating gaps by 2 mm along the positive X direction in the figure.
  • FIG. 3 is a schematic view showing the operation of the rotating grating of Embodiment 1.
  • 301 is a C-arm frame
  • 106 is a rotating grating
  • 102 is a flat panel detector
  • 201 is a first group of gratings in a rotating grating
  • 206 is a sixth group of gratings in a rotating grating.
  • the X-ray source with the rotating grating and the flat panel detector are mounted on the frame, and the random frame rotates around the imaging target when the projection image is acquired.
  • the rotating grating limits the rays emitted by the X-ray source to a plurality of narrow cone beams (shown by dashed lines in the figure).
  • dashed lines shown by dashed lines in the figure.
  • the first group of gratings 201 in the rotating grating is located between the focus and the imaging target, and the rays emitted by the X-ray source pass through the grating, causing the flat panel detector to be exposed to a group of strip-like regions on the left side.
  • the exposure area is constantly switched from left to right and the projected image is passed back to the image reconstruction workstation.
  • the sixth set of gratings 206 in the rotating grating is rotated between the focus and the imaging target, as shown in the right figure of FIG. 3, the rays emitted by the X-ray source pass through the grating, causing the flat panel detector to be exposed to a group of strips on the right side.
  • the rotating grating needs to be rotated 360 rpm, that is, the imaging target 360 times is scanned in a left-to-right manner as described above to obtain sufficient reconstruction information.

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Abstract

一种旋转光栅锥形束CT成像设备，此成像设备由机架（301）、机架角度传感器（104）、装有旋转光栅（106）的X射线源（101）、平板探测器（102）、主控制器（103）和图像重建工作站（105）组成。与通常的锥形束CT成像设备相同，此成像设备也采用开放式结构。与通常的锥形束CT成像设备不同的是，射线源（101）发射出来的射线被旋转光栅（113）限制为多个窄锥形束或扇形束。在射线源（101）和探测器（102）绕成像目标旋转过程中，通过旋转光栅（106）的旋转使窄锥形束或扇形束在平板探测器（102）上的投影图像不断往复运动，以获取整个扫描区域内成像目标的投影信息。最后这些投影信息在图像重建工作站（105）中被重建为容积图像。通过此变焦点扫描的方式，既可以保留锥形束CT成像设备开放结构的优点，又获得了扇形束CT成像设备可以抑制散射光子产生高品质图像的优点。

Description

无标题 技术领域
X线成像设备
背景技术
目前，锥形束CT已经广泛的应用于口腔医学和肿瘤放疗，具有开放式结构，使用方便的优点。但是，与扇形束CT相比，仍存在图像密度信息不准确的缺点。
锥形束CT在获取投影图像时，散射光子对投影图像的影响，是导致扇形束CT图像密度不准确的主要原因。目前，主要有两类方法用来减少散射光子的影响：一类是物理的方法。比如采用限束装置限制锥形束的范围。因为锥形束CT的锥角越小，投影图像中散射光子的成分也越少。但是限制锥形束的范围的同时也限制了成像的范围。对于较大的成像目标此方法就不能适用。另一种物理的方法是在成像目标和平板探测器之间加反散射栅格。反散射栅格虽然可以抑制投影图像中的散射光子，但是也会引入噪声，对于成像目标到探测器距离较小的情况其效果较好。但对于成像目标到探测器距离较大的情况(比如图像引导放疗中使用的集成到加速器上的锥形束CT)，添加反散射栅格的效果有限。另一类方法是在投影图像采集后的后处理方法。比如采用monte carlo算法，可以准确的估计投影图像中散射光子的分布。从而从投影图像中减去散射光子的影响，但是即便采用一些简化计算技术，monte carlo算法超大的计算量使其不能在临床可接受的时间内产生高分辨率的散射分布。采用解析模型计算散射光子的分布，虽然具有较快的计算速度，但是对于复杂的成像目标，会产生较大的计算偏差。再比如噪声抑制重构算法在重构图像时将投影图像中的散射光子作为噪声，也可以在一定程度上减少它的影响。
虽然上述技术在减少散射光子的影响方面有其作用，但也都有其局限性。目前,锥形束CT重建图像密度准确性仍明显不及传统的扇形束CT。
考虑到，锥形束CT的锥角越小，投影图像中散射光子的成分也越少。我们发明了一种旋转光栅锥形束CT成像设备，利用光栅将射线源发出的X线限制为多个窄角锥形束或扇形束，再通过光栅的旋转移动窄角锥形束或扇形束的位置，获取成像目标不同区域的投影图像，从而大大减少了散射光子对图像质量的影响。
发明内容
受到扇形束CT的启发，考虑到越小的射束(或越窄的射束)散射光子的成分越小,我们发明了一种旋转光栅锥形束CT成像设备。
此成像设备由机架及其驱动装置、机架角度传感器、装有旋转光栅的X射线源、平板探测器、主控制器和图像重建工作站组成。机架驱动装置在图像采集过程中驱动机架围绕成像目标旋转。装有旋转光栅的X射线源和平板探测器安装在机架上，可随机架一同旋转。装有旋转光栅的X射线源由X射线源、旋转光栅驱动装置、光栅角度传感器和旋转光栅组成。旋转光栅限制射线源中发出的X线为多个窄角锥形束或扇形束，且位于不同旋转角度上的光栅缝隙位置不同，使得在旋转光栅转动时可以变换透过光栅的窄角锥形束或扇形束的位置。在采集投影图像的过程中，装有旋转光栅的X射线源在随机架旋转的同时，旋转光栅也在围绕X射线源旋转，使透过光栅的窄角锥形束或扇形束的投影图像扫描整个平板探测器，以获取整个容积图像的投影信息。这样，投影图像不是由一个锥形束投影得到的，而是通过多个窄锥形束不断往复扫描的方式得到的，窄锥形束可以使更多的散射线被去除，减少散射光子对投影图像的影响，从而重建出高清晰的CT图像。
旋转光栅角度传感器实时检测光栅的旋转角度，并将此角度信息传输给主控制器。主控制器用来同步光栅旋转和平板探测器的图像采集。
机架角度传感器实时检测机架的旋转角度，并将此角度信息传输给主控制器。主控制器 记录每一幅投影图像采集时的机架角度。
获取的投影图像，被光栅遮挡部分被认为是散射信号，没有被光栅遮挡的部分被认为是主X线信号和散射信号的叠加。采用插值算法，比如三次样条插值，可以通过光栅遮挡部分的散射信号估计没有被光栅遮挡部分的散射信号。这样，没有被光栅遮挡部分的投影信号减去估计的散射信号，就可以得到主X线的投影信号。
图像重建工作站利用这些主X线投影信号、从主控制器获取的对应的机架角度,采用FDK重建算法、压缩感知重建算法或迭代优化重建算法重建三维容积图像。
此成像设备通过旋转光栅的方式，即利用了窄锥形束或扇形束可以抑制散射光子产生高品质图像的优点，又获得了锥形束CT成像设备的开放式结构。
附图说明
图1实施例1各部分间数据通信示意图
图2实施例1旋转光栅图
图3实施例1旋转光栅工作示意图
具体实施方式
具体实施例1
图1展示了一个旋转光栅锥形束CT成像设备的实施例。
图1中101为带有旋转光栅的X射线源，当光栅旋转时，可以改变透过光栅的X射束的位置。其中106为钨合金材料的旋转光栅、113为光栅角度传感器、114为旋转光栅驱动装置。旋转光栅将X射线源中产生的射线限制为多个窄角锥形束。图1中102为平板探测器，105为图像重建工作站，107为安装在图像重建工作站上的图像采集卡。
图1中103为主控制器。主控制器通过机架驱动装置和旋转光栅驱动装置驱动机架和光栅旋转。主控制器通过机架角度传感器104和光栅角度传感器113获取机架和光栅的角度信号。主控制器还用来同步X射线源出束、光栅的旋转与平板探测器的投影信号采集工作。其工作过程为：
a)图像重建工作站发送开始图像采集命令给主控制器。
b)主控制器通过旋转光栅驱动装置驱动光栅以每秒6转的角速度旋转。
c)主控制器通过机架驱动装置驱动机架以每秒6度的角速度旋转。
d)主控制器通过光栅角度传感器检测到光栅旋转，并当新的一组光栅进入X射线源和成像目标之间时发送控制信号给给平板探测器，清除平板探测器的图像数据。
e)主控制器发送控制信号给X射线源，使X射线源出束。
f)主控制器从机架角度传感器读取曝光起始机架角度。
g)曝光指定时间后，图像重建工作站通过图像采集卡读取平板探测器的图像数据。
h)主控制器发送控制信号给X射线源，使X射线源停止出束。
i)主控制器读取曝光结束机架角度。
j)重新回到步骤d)，依照步骤d)e)f)g)h)i)往复循环，直到机架完成360度旋转。
图像重建工作站先要对从探测器读取的投影图像进行预处理，通过三次样条插值算法利用光栅遮挡部分的散射信号估计没有被光栅遮挡部分的散射信号，并将此估计散射信号从没有被光栅遮挡部分的投影图像中去除。
最后，图像重建工作站利用去除了散射信号的投影图像、从主控制器获取的此投影图像对应的机架角度,采用压缩感知重建算法重建三维容积图像。
图1中信号108为主控制器发送给带有旋转光栅的X射线源的控制信号和应答；信号109为主控制器发送给平板探测器的控制信号和应答；信号110是图像重建工作站发送给平 板探测器的控制信号和读取的投影图像；信号111是主控制器发送给机架驱动装置的控制信号和机架角度传感器发送给主控制器的机架角度；信号112是图像重建工作站发送给主控制器的控制信号和返回的各个投影图像对应的机架角度等信息。
图2展示了实施例1中的旋转光栅，光栅是钨合金材质，每隔60度一组光栅，共6组光栅，依次是201、202、203、204、205、206。每组光栅由6条缝隙构成，每个缝隙宽3mm，同一组中相邻缝隙中心间距12mm。从201开始，后一组光栅缝隙比前一组光栅缝隙，整体沿图中X正方向偏移2mm。
图3展示了实施例1旋转光栅工作的示意图。图3中301为C型臂机架，106为旋转光栅，102为平板探测器，201为旋转光栅中第1组光栅，206为旋转光栅中第6组光栅。带有旋转光栅的X射线源与平板探测器都安装在机架上，在采集投影图像时，随机架一起绕成像目标旋转。旋转光栅将X射线源发出的射线限制为多个窄锥形束(如图中虚线所示)。图3左图中旋转光栅中第1组光栅201位于焦点和成像目标之间，X射线源发出的射线通过光栅，使平板探测器略靠左边的一组条状区域曝光。在光栅旋转过程中，曝光区域从左到右不断切换位置，并将投影图像传回图像重建工作站。直到旋转光栅中第6组光栅206旋转到焦点和成像目标之间，如图3右图所示，X射线源发出的射线通过光栅，使平板探测器略靠右边的一组条状区域曝光，完成对成像目标的一次完整扫描。在机架旋转一周的过程中，旋转光栅需要旋转360转，即以上述从左至右的方式扫描成像目标360遍，以获得足够的重建信息。

Claims (9)

  1. 本发明公开了一种旋转光栅锥形束CT成像设备，其特征在于此设备由机架及其驱动装置、机架角度传感器、装有旋转光栅的X射线源、平板探测器、主控制器和图像重建工作站组成。
  2. 根据权利要求1所述的机架及其驱动装置，其特征在于机架驱动装置在图像采集过程中驱动机架围绕成像目标旋转。
  3. 根据权利要求1所述的装有旋转光栅的X射线源，其特征在于旋转光栅在图像采集的过程中围绕X射线源旋转。
  4. 根据权利要求1所述的装有旋转光栅的X射线源，其特征在于旋转光栅限制射线源中发出的X线为多个窄角锥形束或扇形束。
  5. 根据权利要求1所述的旋转光栅，其特征在于旋转光栅由位于不同旋转角度上的几组光栅构成，使得在旋转光栅转动时可以变换透过光栅的窄角锥形束或扇形束的位置。
  6. 根据权利要求1所述的装有旋转光栅的X射线源，其特征在于此射线源安装在机架上，在采集投影图像的过程中随机架一起旋转，且在随机架旋转的同时，旋转光栅也在围绕X射线源旋转，使透过光栅的窄角锥形束或扇形束的投影图像扫描整个平板探测器，并不断重复这个扫描过程。
  7. 权利要求1所述的平板探测器，其特征在于此探测器安装在机架上，在采集投影图像的过程中随机架一起旋转。
  8. 权利要求1所述的图像重建工作站，其特征在于此图像重建工作站利用从探测器读取的投影图像中被光栅遮挡部分的投影信号估计窄角锥形束或扇形束部分中散射信号的分布，并将估计的散射信号从投影图像中去除。
  9. 权利要求1所述的图像重建工作站，其特征在于此图像重建工作站利用已去除散射信号的投影图像、从主控制器获取的此投影图像对应的旋转光栅角度和机架角度,采用FDK重建算法、压缩感知重建算法或迭代优化重建算法重建三维容积图像。
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