Image reconstruction system and method

Patent metadata

Field	Value
Publication number	US-10600214-B2
Application number	US-201816199016-A
Country	US
Kind code	B2
Filing date	Nov 23, 2018
Priority date	Sep 15, 2015
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

A method and system for image reconstruction are provided. A projection image of a projection object may be obtained. A processed projection image may be generated based on the projection image through one or more pre-process operations. A reconstructed image including an artifact may be reconstructed based on the processed projection image. The artifact may be a detector edge artifact, a projection object edge artifact, and a serrated artifact. The detector edge artifact, the projection object edge artifact, and the serrated artifact may be removed from the reconstructed image.

First claim

We claim:

1. A method comprising:
obtaining a projection image of a projection object, the projection image being acquired by an imaging device, the imaging device including a radiation source and a detector;
reconstructing, by the processor, the projection image to generate a reconstructed image including an artifact, the artifact including at least a serrated artifact caused by arcing of the radiation source; and
removing, by the processor, the artifact in the reconstructed image, the removing the artifact in the reconstructed image including removing at least the serrated artifact.

2. The method of claim 1 , wherein the reconstructing the projection image to generate the reconstructed image further comprises:
pre-processing, by the processor, the projection image to generate a processed projection image; and
reconstructing, by the processor, the processed projection image to generate the reconstructed image, wherein the pre-processing the projection image further including:
segmenting a region of interest in the projection image to generate a segmented projection image;
generating a negative film of the segmented projection image; and
correcting a geometrical error of the negative film of the segmented projection image to generate the processed projection image.

3. The method of claim 2 , the reconstructing the processed projection image to generate the reconstructed image including:
filtering the processed projection image to generate a filtered projection image including a highlighted artifact and an X-ray attenuation artifact;
correcting the highlighted artifact and the X-ray attenuation artifact in the filtered projection image to generate a first image; and
performing back projection to generate the reconstructed image based on the first image.

4. The method of claim 2 , the segmenting a region of interest in the projection image to generate a segmented projection image comprising:
determining an average gray value of one or more pixels of the projection image;
for each pixel of the one or more pixels of the projection image, assigning a first mark or a second mark to the pixel based on a relationship between a gray value of the pixel and the average gray value; and
determining a boundary of the region of interest based on the assigned mark of each pixel of the one or more pixels of the projection image.

5. The method of claim 4 , the boundary of the region of interest is determined based on a seed filling algorithm.

6. The method of claim 1 , the reconstructed image including a tomographic image, and the removing the artifact including:
determining a mapping position of a detector edge of the detector in the tomographic image;
determining a projection object edge of the projection object in the tomographic image;
determining an intersection point corresponding to the projection object edge and the mapping position of the detector edge;
determining dislocation information of the intersection point based on the intersection point and the serrated artifact; and
removing the serrated artifact based on the intersection point and the dislocation information of the intersection point.

7. The method of claim 6 , the determining a mapping position of the detector edge in the tomographic image including:
determining a first geometric position relationship between the radiation source and the detector;
determining a second geometric position relationship between the projection image and the tomographic image;
determining mapping coordinates of pixels in the projection image based on the first geometric position relationship and the second geometric position relationship; and
determining the mapping position of the detector edge based on the mapping coordinates of pixels in the projection image and an imaging area of the detector in the projection image.

8. The method of claim 6 , the dislocation information of the intersection point is a horizontal distance between the intersection point and a point on an edge of the serrated artifact.

9. The method of claim 6 , the removing the serrated artifact based on the intersection point and the dislocation information of the intersection point including:
creating a projection object template of the tomographic image;
removing the serrated artifact in the projection object template to obtain a corrected projection object template; and
removing the serrated artifact in the tomographic image based on the corrected projection object template.

10. A method for removing a scattered artifact in a tomographic image of a mammary gland, the tomographic image being acquired by an imaging device that includes a radiation source and a detector, the artifact caused by arcing of the radiation source, the method comprising:
determining a mapping position of a detector edge of the detector in the tomographic image;
determining a mammary gland edge of the mammary gland in the tomographic image;
determining an intersection point corresponding to the mammary gland edge and the mapping position of the detector edge;
determining dislocation information of the intersection point based on the intersection point and the serrated artifact; and
removing the serrated artifact based on the intersection point and the dislocation information of the intersection point.

11. The method of claim 10 , the determining a mapping position of the detector edge in the tomographic image including:
determining a first geometric position relationship between the radiation source and the detector;
determining a second geometric position relationship between a projection image of the mammary gland and the tomographic image;
determining mapping coordinates of pixels in the projection image based on the first geometric position relationship and the second geometric position relationship; and
determining the mapping position of the detector edge based on the mapping coordinates of pixels in the projection image and an imaging area of the detector in the projection image.

12. The method of claim 10 , the dislocation information of the intersection point is a horizontal distance between the intersection point and a point on an edge of the serrated artifact.

13. The method of claim 10 , the removing the serrated artifact based on the intersection point and the dislocation information of the intersection point including:
creating a projection object template of the tomographic image;
removing the serrated artifact in the projection object template to obtain a corrected projection object template; and
removing the serrated artifact in the tomographic image based on the corrected projection object template.

14. A system comprising:
at least one storage medium including a set of instructions for image processing;
at least one processor in communication with the at least one storage medium, wherein
when executing the set of instructions, the at least one processor is configured to direct the system to:
obtain a projection image of a projection object, the projection image being acquired by an imaging device, the imaging device including a radiation source and a detector;
reconstruct the projection image to generate a reconstructed image including an artifact, the artifact at least including a serrated artifact caused by arcing of the radiation source; and
remove the artifact in the reconstructed image, the removing the artifact in the reconstructed image at least including removing the serrated artifact.

15. The system of claim 14 , wherein to reconstruct the projection image to generate a reconstructed image, the at least one processor is further configured to direct

Assignees

• Shanghai United Imaging Healthcare Co Ltd

Inventors

• Yang Le
• Zhou Haihua
• Feng Juan
• Cui Kai
• Qi Ji
• Zhang Na
• Chen Hao
• Niu Jie
• Han Yecheng
• Teng Wanli
• Ma Yange

Classifications

• A61B6/032

  Transmission computed tomography [CT] · CPC title

• G06T7/12

  Edge-based segmentation · CPC title

• G06T7/13

  Edge detection · CPC title

• A61B5/0095

  by applying light and detecting acoustic waves, i.e. photoacoustic measurements · CPC title

• A61B6/00

  Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment (instruments measuring radiation intensity for application in the field of nuclear medicine, e.g. in vivo counting, G01T1/161) · CPC title