WO2017111996A1 - Method and apparatus for recovering ct data of low credibility - Google Patents

Method and apparatus for recovering ct data of low credibility Download PDF

Info

Publication number
WO2017111996A1
WO2017111996A1 PCT/US2016/038462 US2016038462W WO2017111996A1 WO 2017111996 A1 WO2017111996 A1 WO 2017111996A1 US 2016038462 W US2016038462 W US 2016038462W WO 2017111996 A1 WO2017111996 A1 WO 2017111996A1
Authority
WO
WIPO (PCT)
Prior art keywords
region
projection
low credibility
module
tracks
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/US2016/038462
Other languages
French (fr)
Inventor
Ximiao Cao
Xueli Wang
Mengdie WANG
Chen Li
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Co
Original Assignee
General Electric Co
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
Application filed by General Electric Co filed Critical General Electric Co
Publication of WO2017111996A1 publication Critical patent/WO2017111996A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T12/00—Tomographic reconstruction from projections
    • G06T12/30—Image post-processing, e.g. metal artefact correction
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T12/00—Tomographic reconstruction from projections
    • G06T12/20—Inverse problem, i.e. transformations from projection space into object space
    • 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
    • A61B6/52—Devices using data or image processing specially adapted for radiation diagnosis

Definitions

  • the present invention relates to the technical field of Computed Tomography (CT), particularly to a method and apparatus for recovering CT data of low credibility.
  • CT Computed Tomography
  • a detector may collect X-rays that pass through an object to be scanned and convert those X-rays into electric signals. Those electric signals are recorded and then constitute CT original data, which is also called CT projection data. After reconstructing the CT projection data by a corresponding reconstruction algorithm, a CT image may be obtained.
  • the CT projection data would include data of low credibility. Artifacts would appear on the CT image obtained by reconstruction with those data.
  • the existing method for recovering data of low credibility in the CT projection data usually performs data recovery on one or more of three dimensions, i.e., view, a number of channels of the detector along the X-direction and a number of rows of the detector along the Z-direction generated by the projection data based on the three dimensions.
  • the accuracy of the data recovered by the existing method is not high enough, and the recovering effect is not good for the region where a density difference of objects is larger on the CT image.
  • One embodiment of the present invention provides a method for recovering CT data of low credibility, comprising: acquiring a low credibility region at a projection space; performing a forward projection on all or some of pixel points on a reconstructed image to obtain projection tracks; and recovering an overlapped region on which the projection tracks pass through the low credibility region.
  • Another embodiment of the present invention provides an apparatus for recovering CT data of low credibility, comprising: a low credibility region acquisition module for acquiring a low credibility region at a projection space; a forward projection module for performing a forward projection on all or some of pixel points on a reconstructed image to obtain projection tracks; and an overlapped region recovery module for recovering an overlapped region on which the projection tracks pass through the low credibility region.
  • FIG. 1 is a schematic flow chart illustrating one embodiment of a method for recovering CT data of low credibility of the present invention
  • FIG. 2 is a schematic flow chart illustrating one embodiment of acquiring a low credibility region at a projection space during the process of recovering CT data of low credibility of the present invention
  • FIG. 3 is a schematic flow chart illustrating one embodiment of acquiring a low credibility region at a projection space during the process of recovering CT data of low credibility of the present invention
  • Fig. 4 is a schematic flow chart illustrating one embodiment of recovering an overlapped region where the projection tracks pass through the low credibility region during the process of recovering CT data of low credibility of the present invention
  • Fig. 5 is a schematic diagram illustrating that a projection track passes through the low credibility region
  • Fig. 6 is a schematic diagram illustrating a credible region on the projection track as shown in Fig. 5 ;
  • Fig. 7 is a schematic diagram illustrating interpolation on the overlapped region on the projection track
  • Fig. 8A illustrates a reconstructed image obtained by reconstruction with the projection data containing data of low credibility
  • Fig. 8B illustrates a reconstructed image obtained by reconstruction after recovering the data of low credibility using the prior art
  • Fig. 8C illustrates a reconstructed image obtained by reconstruction after recovering the data of low credibility using the technical solution of the present invention
  • Fig. 9 is a schematic block diagram illustrating one embodiment of an apparatus for recovering CT data of low credibility of the present invention.
  • FIG. 1 is a schematic flow chart illustrating one embodiment of a method 100 for recovering CT data of low credibility of the present invention.
  • Step 101 a low credibility region at a projection space is acquired.
  • the low credibility region may be a low credibility region on which a hardware defect is reflected onto the projection space, and may also be a low credibility region on which a metal on the scanned object is reflected onto the projection space.
  • the low credibility region may be a region on the projection space to which a metal region on the initial reconstructed image corresponds, and may also be a region on the projection space to which some known detector channels of low performance correspond, and may further be a region reflected onto the projection space due to the reasons such as tube spit.
  • the corresponding detector channel may be directly selected on the projection space, and a region composed of all data corresponding to the channel may be regarded as the low credibility region.
  • a region composed of all data for the view may be regarded as the low credibility region.
  • Step 101 may comprise the following Sub-Steps 201 to 202, i.e., a low credibility region at the projection space may be acquired by the following Sub-Steps 201 to 202.
  • Sub-Step 201 an objective region is selected on the reconstructed image.
  • the reconstructed image may be obtained by a method of reconstructing the CT image with projection data containing data of low credibility.
  • the objective region may be selected.
  • the objective region may be a region where an artifact resides, and may also be a region of a lower credibility considered by the user.
  • Sub-Step 202 a forward projection is performed on the objective region to obtain the low credibility region.
  • a forward projection may be performed on the objective region selected by Sub-Step 201, and a region of the objective region at the projection space, i.e., low credibility region, may just be obtained.
  • Step 101 may also comprise the following Sub-Steps 301 to 302, i.e., a low credibility region at the projection space may be acquired by the following Sub-Steps 301 to 302.
  • Sub-Step 301 artifact information is acquired on the reconstructed image.
  • the low credibility region is computed in accordance with the artifact information.
  • information such as the view, the number of channels of the detector along the X-direction, the number of rows of the detector along the Z-direction and the like may be computed from the direction of the steak artifact and the distance from the steak artifact to the rotation center, thereby determining the region of the steak artifact in the projection space.
  • the view, the number of channels and the number of rows of the ring artifact or the band artifact may be computed from the radius and the circumference coverage range of the ring artifact or the band artifact, thereby determining the region of the ring artifact or the band artifact in the projection space.
  • Step 102 a forward projection is performed on all or some of pixel points on a reconstructed image to obtain projection tracks.
  • a forward projection is performed on pixel points in a region on the reconstructed image where objects of larger densities (for example, metal, skeleton, etc.,) reside to obtain projection tracks of those pixel points.
  • objects of larger densities for example, metal, skeleton, etc.
  • a forward projection is performed on pixel points in a region on the reconstructed image where a density difference of objects is larger (for example, a region where substance of high density is adjacent to substance of low density) to obtain projection tracks of those pixel points.
  • Reconstructing an image as stated herein may be obtaining a reconstructed image by a method of CT image reconstruction with projection data containing data of low credibility.
  • Step 103 an overlapped region on which the projection tracks pass through the low credibility region is recovered.
  • Step 103 may include the following Sub-steps 401 to 403.
  • Sub-Step 401 an overlapped region is selected on the projection tracks.
  • the thinner curve is a projection track of one pixel point obtained by Step 102, and the thicker curve band represents a low credibility region obtained by Step 101. And the part on the thinner curve that passes through the thicker curve band is just the overlapped region.
  • Sub-Step 402 an interpolation is performed on the overlapped region in accordance with the trends of the projection tracks.
  • the projection tracks are sinusoidal curves, therefore in one embodiment of the present invention, an interpolation recovery may be performed for the overlapped region on the projection tracks in accordance with the trends of the sinusoidal curves.
  • the part on which the projection track does not pass through the low credibility region may be regarded as a credible region. Therefore, an extrapolation may be performed on the overlapped region using the data within the credible region and in accordance with a sinusoidal change pattern of the projection track, so as to obtain the values of the projection track positioned within the overlapped region.
  • Fig. 7 shows a track of a projection track within the overlapped region, the projection track being obtained by performing an interpolation on the overlapped region. Thus, a complete projection track may be obtained.
  • the projection tracks may be sinusoidal-like curves or other curves of any higher powers, therefore in another embodiment of the present invention, an interpolation recovery may be performed for the overlapped region on the projection tracks in accordance with the trends and the change patters of the sinusoidal-like curves or the curves of higher powers.
  • Sub-Step 403 the projection tracks after being interpolated are weighted and summed.
  • the complete projection tracks obtained after interpolation may be weighted and summed.
  • the weights of the projection tracks may be equal.
  • the projection tracks of greater strength may be assigned greater weights as well.
  • the CT data after being recovered may further be merged with the CT data before being recovered.
  • Such merging process may be a weighted superimposing process, for instance, the projection data after being recovered may be trusted entirely while the data before being recovered may not be trusted at all.
  • the data after being recovered may also be trusted partly, in this way, the data before being recovered and the data after being recovered may be assigned with some weights respectively and the two may be weighted superimposed with each other.
  • the data as stated herein may be projection data, and may also be data of the reconstructed image, i.e., this merging may be performed at a projection space, and may also be performed at an image space.
  • the present invention also provides the corresponding apparatus.
  • Fig. 9 is a schematic block diagram illustrating one embodiment of an apparatus for recovering CT data of low credibility of the present invention.
  • an apparatus 900 may comprise: a low credibility region acquisition module 901 for acquiring a low credibility region at a projection space; a forward projection module 902 for performing a forward projection on all or some of pixel points on a reconstructed image to obtain a projection track; and an overlapped region recovery module 903 for recovering an overlapped region on which the projection tracks pass through the low credibility region.
  • the low credibility region acquisition module 901 may further comprise: an objective region selection module for selecting an objective region on the reconstructed image; and an objective region forward projection module for performing a forward projection on the objective region to obtain the low credibility region.
  • the low credibility region acquisition module 901 may further comprise: an artifact information acquisition module for acquiring artifact information on the reconstructed image; and a module for computing the low credibility region in accordance with the artifact information.
  • the forward projection module 902 may further comprise: a large density region forward projection module for performing a forward projection on pixel points in a region on the reconstructed image where objects of larger densities reside.
  • the forward projection module 902 may further comprise: a region of large difference forward projection module for performing a forward projection on pixel points in a region on the reconstructed image where a density difference of objects is larger.
  • the overlapped region recovery module 903 may further comprise: an overlapped region selection module for selecting the overlapped region on the projection tracks; an interpolation module for performing an interpolation on the overlapped region in accordance with the trends of the projection tracks; and a weighting and summing module for weighting and summing the projection tracks after being interpolated.
  • the interpolation module may further comprise: a sinusoidal trend interpolation module for performing an interpolation on the overlapped region in accordance with a trend of a sinusoidal curve.
  • the overlapped region recovery module 903 may further comprise: a data merging module for merging the CT data after being recovered with the CT data before being recovered.
  • the apparatus of the present invention is capable of recovering CT projection data more accurately while avoiding new artifacts due to inaccurate interpolation. Furthermore, the apparatus of the present invention can also reduce requirements for hardware on a CT image chain, thereby reducing the cost.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Apparatus For Radiation Diagnosis (AREA)
  • Image Processing (AREA)

Abstract

The present invention relates to a method and apparatus for recovering CT data of low credibility. The method comprises: acquiring a low credibility region at a projection space; performing a forward projection on all or some of pixel points on a reconstructed image to obtain projection tracks; and recovering an overlapped region on which the projection tracks pass through the low credibility region.

Description

METHOD AND APPARATUS FOR RECOVERING CT DATA
OF LOW CREDIBILITY
FIELD
[0001] The present invention relates to the technical field of Computed Tomography (CT), particularly to a method and apparatus for recovering CT data of low credibility.
BACKGROUND
[0002] In a CT device, a detector may collect X-rays that pass through an object to be scanned and convert those X-rays into electric signals. Those electric signals are recorded and then constitute CT original data, which is also called CT projection data. After reconstructing the CT projection data by a corresponding reconstruction algorithm, a CT image may be obtained.
[0003] Because of the reasons that the performance of some channels on the detector is degraded, the object to be scanned contains metal and the like, the CT projection data would include data of low credibility. Artifacts would appear on the CT image obtained by reconstruction with those data.
[0004] The existing method for recovering data of low credibility in the CT projection data usually performs data recovery on one or more of three dimensions, i.e., view, a number of channels of the detector along the X-direction and a number of rows of the detector along the Z-direction generated by the projection data based on the three dimensions. However, the accuracy of the data recovered by the existing method is not high enough, and the recovering effect is not good for the region where a density difference of objects is larger on the CT image.
[0005] Therefore, there is a need to provide a method and apparatus for recovering CT data of low credibility, which is capable of recovering CT data more accurately.
SUMMARY
[0006] One embodiment of the present invention provides a method for recovering CT data of low credibility, comprising: acquiring a low credibility region at a projection space; performing a forward projection on all or some of pixel points on a reconstructed image to obtain projection tracks; and recovering an overlapped region on which the projection tracks pass through the low credibility region.
[0007] Another embodiment of the present invention provides an apparatus for recovering CT data of low credibility, comprising: a low credibility region acquisition module for acquiring a low credibility region at a projection space; a forward projection module for performing a forward projection on all or some of pixel points on a reconstructed image to obtain projection tracks; and an overlapped region recovery module for recovering an overlapped region on which the projection tracks pass through the low credibility region.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present invention can be better understood in light of the following description of embodiments of the present invention with reference to the accompanying drawings, in which:
[0009] Fig. 1 is a schematic flow chart illustrating one embodiment of a method for recovering CT data of low credibility of the present invention;
[0010] Fig. 2 is a schematic flow chart illustrating one embodiment of acquiring a low credibility region at a projection space during the process of recovering CT data of low credibility of the present invention;
[0011] Fig. 3 is a schematic flow chart illustrating one embodiment of acquiring a low credibility region at a projection space during the process of recovering CT data of low credibility of the present invention;
[0012] Fig. 4 is a schematic flow chart illustrating one embodiment of recovering an overlapped region where the projection tracks pass through the low credibility region during the process of recovering CT data of low credibility of the present invention;
[0013] Fig. 5 is a schematic diagram illustrating that a projection track passes through the low credibility region;
[0014] Fig. 6 is a schematic diagram illustrating a credible region on the projection track as shown in Fig. 5 ;
[0015] Fig. 7 is a schematic diagram illustrating interpolation on the overlapped region on the projection track;
[0016] Fig. 8A illustrates a reconstructed image obtained by reconstruction with the projection data containing data of low credibility;
[0017] Fig. 8B illustrates a reconstructed image obtained by reconstruction after recovering the data of low credibility using the prior art;
[0018] Fig. 8C illustrates a reconstructed image obtained by reconstruction after recovering the data of low credibility using the technical solution of the present invention;
[0019] Fig. 9 is a schematic block diagram illustrating one embodiment of an apparatus for recovering CT data of low credibility of the present invention.
DETAILED DESCRIPTION
[0020] Hereafter, a detailed description will be given for preferred embodiments of the present disclosure. It should be pointed out that in the detailed description of the embodiments, for simplicity and conciseness, it is impossible for the Description to describe all the features of the practical embodiments in details. It should be understood that in the process of a practical implementation of any embodiment, just as in the process of an engineering project or a designing project, in order to achieve a specific goal of the developer and in order to satisfy some system-related or business-related constraints, a variety of decisions will usually be made, which will also be varied from one embodiment to another. In addition, it can also be understood that although the effort made in such developing process may be complex and time-consuming, some variations such as design, manufacture and production on the basis of the technical contents disclosed in the disclosure are just customary technical means in the art for those of ordinary skilled in the art relating to the contents disclosed in the present invention, which should not be regarded as insufficient disclosure of the present invention.
[0021] Unless defined otherwise, all the technical or scientific terms used in the Claims and the Description should have the same meanings as commonly understood by one of ordinary skilled in the art to which the present disclosure belongs. The terms "first", "second" and the like in the Description and the Claims of the present utility model do not mean any sequential order, number or importance, but are only used for distinguishing different components. The terms "a", "an" and the like do not denote a limitation of quantity, but denote the existence of at least one. The terms "comprises", "comprising", "includes", "including" and the like mean that the element or object in front of the "comprises", "comprising", "includes" and "including" covers the elements or objects and their equivalents illustrated following the "comprises", "comprising", "includes" and "including", but do not exclude other elements or objects. The term "coupled" or "connected" or the like is not limited to being connected physically or mechanically, nor limited to being connected directly or indirectly.
[0022] In order to make the purpose, the technical solutions and the advantages of the invention more apparent, the technical solutions of the present invention will be set forth clearly and fully in the following by combining with specific embodiments of the invention and the corresponding accompanying drawings. Obviously, the described embodiments are merely part— not all— of the embodiments in the present invention. In view of the embodiments in the present invention, other embodiments made by one of ordinary skilled in the art without inventive work all fall within the scope of protection of the invention.
[0023] In accordance with the embodiments of the present invention, a method for recovering CT data of low credibility is provided.
[0024] Referring to Fig. 1, which is a schematic flow chart illustrating one embodiment of a method 100 for recovering CT data of low credibility of the present invention.
[0025] As shown in Fig. 1, in Step 101, a low credibility region at a projection space is acquired.
[0026] The low credibility region may be a low credibility region on which a hardware defect is reflected onto the projection space, and may also be a low credibility region on which a metal on the scanned object is reflected onto the projection space. For example, the low credibility region may be a region on the projection space to which a metal region on the initial reconstructed image corresponds, and may also be a region on the projection space to which some known detector channels of low performance correspond, and may further be a region reflected onto the projection space due to the reasons such as tube spit.
[0027] For the situation of known detector channels of low performance, the corresponding detector channel may be directly selected on the projection space, and a region composed of all data corresponding to the channel may be regarded as the low credibility region. For the situation of tube spit, a region composed of all data for the view may be regarded as the low credibility region.
[0028] In one embodiment of the present invention, referring to Fig. 2, Step 101 may comprise the following Sub-Steps 201 to 202, i.e., a low credibility region at the projection space may be acquired by the following Sub-Steps 201 to 202. [0029] In Sub-Step 201, an objective region is selected on the reconstructed image.
[0030] The reconstructed image may be obtained by a method of reconstructing the CT image with projection data containing data of low credibility. On the reconstructed image, the objective region may be selected. The objective region may be a region where an artifact resides, and may also be a region of a lower credibility considered by the user.
[0031] In Sub-Step 202, a forward projection is performed on the objective region to obtain the low credibility region.
[0032] A forward projection may be performed on the objective region selected by Sub-Step 201, and a region of the objective region at the projection space, i.e., low credibility region, may just be obtained.
[0033] In another embodiment of the present invention, referring to Fig. 3, Step 101 may also comprise the following Sub-Steps 301 to 302, i.e., a low credibility region at the projection space may be acquired by the following Sub-Steps 301 to 302.
[0034] In Sub-Step 301, artifact information is acquired on the reconstructed image.
[0035] For some artifacts of specific styles, for example, steak artifact, ring artifact, band artifact and the like, information such as their shapes, positions, sizes and the like may be recognized from the reconstructed image.
[0036] In Sub-Step 302, the low credibility region is computed in accordance with the artifact information.
[0037] For example, information such as the view, the number of channels of the detector along the X-direction, the number of rows of the detector along the Z-direction and the like may be computed from the direction of the steak artifact and the distance from the steak artifact to the rotation center, thereby determining the region of the steak artifact in the projection space. For another example, the view, the number of channels and the number of rows of the ring artifact or the band artifact may be computed from the radius and the circumference coverage range of the ring artifact or the band artifact, thereby determining the region of the ring artifact or the band artifact in the projection space.
[0038] In Step 102, a forward projection is performed on all or some of pixel points on a reconstructed image to obtain projection tracks.
[0039] In one embodiment of the present invention, a forward projection is performed on pixel points in a region on the reconstructed image where objects of larger densities (for example, metal, skeleton, etc.,) reside to obtain projection tracks of those pixel points. [0040] In another embodiment of the present invention, a forward projection is performed on pixel points in a region on the reconstructed image where a density difference of objects is larger (for example, a region where substance of high density is adjacent to substance of low density) to obtain projection tracks of those pixel points.
[0041] Reconstructing an image as stated herein may be obtaining a reconstructed image by a method of CT image reconstruction with projection data containing data of low credibility.
[0042] In Step 103, an overlapped region on which the projection tracks pass through the low credibility region is recovered.
[0043] The part that the projection tracks obtained by Step 102 pass through the low credibility region obtained by Step 101 is just the portion that needs to be recovered in Step 103. In one embodiment of the present invention, with reference to Fig. 4, Step 103 may include the following Sub-steps 401 to 403.
[0044] In Sub-Step 401, an overlapped region is selected on the projection tracks.
[0045] Referring to Fig. 5, in Fig. 5, the thinner curve is a projection track of one pixel point obtained by Step 102, and the thicker curve band represents a low credibility region obtained by Step 101. And the part on the thinner curve that passes through the thicker curve band is just the overlapped region.
[0046] In Sub-Step 402, an interpolation is performed on the overlapped region in accordance with the trends of the projection tracks.
[0047] In the projection space of some CT machines, the projection tracks are sinusoidal curves, therefore in one embodiment of the present invention, an interpolation recovery may be performed for the overlapped region on the projection tracks in accordance with the trends of the sinusoidal curves. As shown in Fig. 6, the part on which the projection track does not pass through the low credibility region may be regarded as a credible region. Therefore, an extrapolation may be performed on the overlapped region using the data within the credible region and in accordance with a sinusoidal change pattern of the projection track, so as to obtain the values of the projection track positioned within the overlapped region. Fig. 7 shows a track of a projection track within the overlapped region, the projection track being obtained by performing an interpolation on the overlapped region. Thus, a complete projection track may be obtained.
[0048] In the projection space of other CT machines, the projection tracks may be sinusoidal-like curves or other curves of any higher powers, therefore in another embodiment of the present invention, an interpolation recovery may be performed for the overlapped region on the projection tracks in accordance with the trends and the change patters of the sinusoidal-like curves or the curves of higher powers.
[0049] In Sub-Step 403, the projection tracks after being interpolated are weighted and summed.
[0050] In one embodiment of the present invention, when a plurality of projection tracks pass the same low credibility region, the complete projection tracks obtained after interpolation may be weighted and summed. The weights of the projection tracks may be equal. The projection tracks of greater strength may be assigned greater weights as well.
[0051] In one embodiment of the present invention, the CT data after being recovered may further be merged with the CT data before being recovered. Such merging process may be a weighted superimposing process, for instance, the projection data after being recovered may be trusted entirely while the data before being recovered may not be trusted at all. The data after being recovered may also be trusted partly, in this way, the data before being recovered and the data after being recovered may be assigned with some weights respectively and the two may be weighted superimposed with each other. The data as stated herein may be projection data, and may also be data of the reconstructed image, i.e., this merging may be performed at a projection space, and may also be performed at an image space.
[0052] So far, a method for recovering CT data of low credibility according to the embodiments of the present invention has been described. In comparison with Fig. 8A, Fig. 8B and Fig. 8C, it can be seen that the method of the present invention is capable of recovering CT projection data more accurately while avoiding new artifacts due to inaccurate interpolation. Furthermore, the method of the present invention can also reduce requirements for hardware on a CT image chain, thereby reducing the cost.
[0053] Similar to the method, the present invention also provides the corresponding apparatus.
[0054] Fig. 9 is a schematic block diagram illustrating one embodiment of an apparatus for recovering CT data of low credibility of the present invention.
[0055] As shown in Fig. 9, an apparatus 900 may comprise: a low credibility region acquisition module 901 for acquiring a low credibility region at a projection space; a forward projection module 902 for performing a forward projection on all or some of pixel points on a reconstructed image to obtain a projection track; and an overlapped region recovery module 903 for recovering an overlapped region on which the projection tracks pass through the low credibility region.
[0056] In one embodiment of the present invention, the low credibility region acquisition module 901 may further comprise: an objective region selection module for selecting an objective region on the reconstructed image; and an objective region forward projection module for performing a forward projection on the objective region to obtain the low credibility region.
[0057] In another embodiment of the present invention, the low credibility region acquisition module 901 may further comprise: an artifact information acquisition module for acquiring artifact information on the reconstructed image; and a module for computing the low credibility region in accordance with the artifact information.
[0058] In one embodiment of the present invention, the forward projection module 902 may further comprise: a large density region forward projection module for performing a forward projection on pixel points in a region on the reconstructed image where objects of larger densities reside.
[0059] In another embodiment of the present invention, the forward projection module 902 may further comprise: a region of large difference forward projection module for performing a forward projection on pixel points in a region on the reconstructed image where a density difference of objects is larger.
[0060] In one embodiment of the present invention, the overlapped region recovery module 903 may further comprise: an overlapped region selection module for selecting the overlapped region on the projection tracks; an interpolation module for performing an interpolation on the overlapped region in accordance with the trends of the projection tracks; and a weighting and summing module for weighting and summing the projection tracks after being interpolated.
[0061] In one embodiment of the present invention, the interpolation module may further comprise: a sinusoidal trend interpolation module for performing an interpolation on the overlapped region in accordance with a trend of a sinusoidal curve.
[0062] In one embodiment of the present invention, the overlapped region recovery module 903 may further comprise: a data merging module for merging the CT data after being recovered with the CT data before being recovered.
[0063] So far, an apparatus for recovering CT data of low credibility according to the embodiments of the present invention has been described. In comparison with Fig. 8A, Fig. 8B and Fig. 8C, it can be seen that similar to the above method, the apparatus of the present invention is capable of recovering CT projection data more accurately while avoiding new artifacts due to inaccurate interpolation. Furthermore, the apparatus of the present invention can also reduce requirements for hardware on a CT image chain, thereby reducing the cost.
[0064] The above descriptions are merely embodiments of the invention and are not intended to restrict the scope of the invention. All kinds of variations and modifications could be made to the present invention to those skilled in the art. Any modifications, alternatives and improvements made within the spirit and principles of the present invention shall fall within the scope of the appended claims.

Claims

What is claimed is:
1. A method for recovering CT data of low credibility, comprising:
acquiring a low credibility region at a projection space;
performing a forward projection on all or some of pixel points on a reconstructed image to obtain projection tracks; and
recovering an overlapped region on which the projection tracks pass through the low credibility region.
2. The method according to Claim 1, wherein the step of acquiring a low credibility region at a projection space further comprises:
selecting an objective region on the reconstructed image; and
performing a forward projection on the objective region to obtain the low credibility region.
3. The method according to Claim 1, wherein the step of acquiring a low credibility region at a projection space further comprises:
acquiring artifact information on the reconstructed image; and
computing the low credibility region in accordance with the artifact information.
4. The method according to Claim 1, wherein the step of performing a forward projection on all or some of pixel points on a reconstructed image to obtain projection tracks further comprises:
performing a forward projection on pixel points in a region on the reconstructed image where objects of larger densities reside.
5. The method according to Claim 1, wherein the step of performing a forward projection on all or some of pixel points on a reconstructed image to obtain projection tracks further comprises:
performing a forward projection on pixel points in a region on the reconstructed image where a density difference of objects is larger.
6. The method according to Claim 1, wherein the step of recovering an overlapped region on which the projection tracks pass through the low credibility region further comprises:
selecting the overlapped region on the projection tracks;
performing an interpolation on the overlapped region in accordance with trends of the projection tracks; and
weighting and summing the projection tracks after being interpolated.
7. The method according to Claim 6, wherein the step of performing an interpolation on the overlapped region in accordance with trends of the projection tracks further comprises: performing an interpolation on the overlapped region in accordance with a trend of a sinusoidal curve.
8. The method according to Claim 6, further comprising:
merging the CT data after being recovered with the CT data before being recovered.
9. An apparatus for recovering CT data of low credibility, comprising:
a low credibility region acquisition module for acquiring a low credibility region at a projection space;
a forward projection module for performing a forward projection on all or some of pixel points on a reconstructed image to obtain projection tracks; and
an overlapped region recovery module for recovering an overlapped region on which the projection tracks pass through the low credibility region.
10. The apparatus according to Claim 9, wherein the low credibility region acquisition module further comprises:
an objective region selection module for selecting an objective region on the reconstructed image; and
an objective region forward projection module for performing a forward projection on the objective region to obtain the low credibility region.
11. The apparatus according to Claim 9, wherein the low credibility region acquisition module further comprises:
an artifact information acquisition module for acquiring artifact information on the reconstructed image; and
a module for computing the low credibility region in accordance with the artifact information.
12. The apparatus according to Claim 9, wherein the forward projection module further comprises:
a large density region forward projection module for performing a forward projection on pixel points in a region on the reconstructed image where objects of larger densities reside.
13. The apparatus according to Claim 9, wherein the forward projection module further comprises:
a region of large difference forward projection module for performing a forward projection on pixel points in a region on the reconstructed image where a density difference of objects is larger.
14. The apparatus according to Claim 9, wherein the overlapped region recovery module further comprises:
an overlapped region selection module for selecting the overlapped region on the projection tracks;
an interpolation module for performing an interpolation on the overlapped region in accordance with trends of the projection tracks; and
a weighting and summing module for weighting and summing the projection tracks after being interpolated.
15. The apparatus according to Claim 14, wherein the interpolation module further comprises:
a sinusoidal trend interpolation module for performing an interpolation on the overlapped region in accordance with a trend of a sinusoidal curve.
16. The apparatus according to Claim 14, wherein the overlapped region recovery module further comprises:
a data merging module for merging the CT data after being recovered with the CT data before being recovered.
PCT/US2016/038462 2015-12-23 2016-06-21 Method and apparatus for recovering ct data of low credibility Ceased WO2017111996A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201510977018.1A CN106910227B (en) 2015-12-23 2015-12-23 A method and device for recovering CT data with low reliability
CN201510977018.1 2015-12-23

Publications (1)

Publication Number Publication Date
WO2017111996A1 true WO2017111996A1 (en) 2017-06-29

Family

ID=59091108

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2016/038462 Ceased WO2017111996A1 (en) 2015-12-23 2016-06-21 Method and apparatus for recovering ct data of low credibility

Country Status (2)

Country Link
CN (1) CN106910227B (en)
WO (1) WO2017111996A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080056437A1 (en) * 2006-08-30 2008-03-06 General Electric Company Acquisition and reconstruction of projection data using a stationary CT geometry
US20120155617A1 (en) * 2010-12-15 2012-06-21 Sandeep Dutta Phantom for spectral ct image system calibration
US20140270448A1 (en) * 2013-03-15 2014-09-18 University Of Macau System and method for attenuation correction in emission computed tomography

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7792238B2 (en) * 2008-02-18 2010-09-07 General Electric Company Method and system for reconstructing cone-beam projection data with reduced artifacts
CN103106676B (en) * 2013-02-05 2016-04-06 南方医科大学 A kind of X ray CT image rebuilding method based on the filtering of low dosage data for projection
CN103617598B (en) * 2013-11-10 2016-08-31 北京工业大学 A kind of CT image metal artifact minimizing technology based on track
CN103793890A (en) * 2014-03-05 2014-05-14 南方医科大学 Method for recovering and processing energy spectrum CT images

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080056437A1 (en) * 2006-08-30 2008-03-06 General Electric Company Acquisition and reconstruction of projection data using a stationary CT geometry
US20120155617A1 (en) * 2010-12-15 2012-06-21 Sandeep Dutta Phantom for spectral ct image system calibration
US20140270448A1 (en) * 2013-03-15 2014-09-18 University Of Macau System and method for attenuation correction in emission computed tomography

Also Published As

Publication number Publication date
CN106910227B (en) 2023-06-13
CN106910227A (en) 2017-06-30

Similar Documents

Publication Publication Date Title
Li et al. Rethinking multi-contrast mri super-resolution: Rectangle-window cross-attention transformer and arbitrary-scale upsampling
US9263164B2 (en) Method and device for correcting artefacts during X-ray imagery, especially computer tomography, with a moving modulator field
CN109920020B (en) Cone beam CT (computed tomography) pathologic projection reconstruction artifact suppression method
Sanaat et al. Deep‐TOF‐PET: Deep learning‐guided generation of time‐of‐flight from non‐TOF brain PET images in the image and projection domains
Mishra et al. Automatic lesion border selection in dermoscopy images using morphology and color features
US20140211911A1 (en) Ct apparatus and an image processing method used by the same
CN109870471B (en) Single-grating-detection cone-beam CT angle sequence scattering acquisition method
WO2017111996A1 (en) Method and apparatus for recovering ct data of low credibility
Sarfati et al. Guiding the classification of hepatocellular carcinoma on 3D CT-scans using deep and handcrafted radiological features
WO2017111997A1 (en) Method and apparatus for recovering raw ct projection data and ct imaging system
KR20210050830A (en) Apparatus and method for improving area segmentation performance in medical image data
CN121121403A (en) Methods, devices, electronic devices, storage media and products for image recognition of cerebral hemorrhage
WO2016032683A1 (en) Method for removing streak from detector cell with performance difference
Armstrong et al. Reduced-count myocardial perfusion SPECT with resolution recovery
Kang Assessment of coronary stenosis using coronary CT angiography in patients with high calcium scores: current limitations and future perspectives
Ruiz Muñoz et al. Comparison of projection and reconstruction techniques in sinograms for breast lesion classification
WO2017111998A1 (en) Apparatus and method for data recovery of raw ct projection data and ct imaging system
Tong et al. PEPC-Net: Progressive Edge Perception and Completion Network for Precise Identification of Safe Resection Margins in Maxillofacial Cysts
Liu et al. Dual Diffusion Models with Unified Weight Fusion Framework for Denoising and Deblurring in Cardiac-gated Myocardial Perfusion SPECT
Wen et al. A superpixel based post-processing approach for segmenting dermoscopy images
RU2778112C2 (en) Method for building synthetic ct images based on mri image data
Wang et al. Development and evaluation of data-driven respiratory gating methods with simulated list-mode PET data
Rong Progress and Regional Application of Artificial Intelligence in Cancer Diagnosis: A Case Study of Qinghai University Affiliated Cancer Hospital
Nguyên et al. Comparison between a count-based and geometrical approach for the assessment of left ventricular dyssynchrony using myocardial perfusion scintigraphy
Wang et al. TD-Net: A Tri-domain network for sparse-view CT reconstruction

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16879516

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 16879516

Country of ref document: EP

Kind code of ref document: A1