CN108992083B - Cone beam computed tomography method for correcting image and system - Google Patents
Cone beam computed tomography method for correcting image and system Download PDFInfo
- Publication number
- CN108992083B CN108992083B CN201810923092.9A CN201810923092A CN108992083B CN 108992083 B CN108992083 B CN 108992083B CN 201810923092 A CN201810923092 A CN 201810923092A CN 108992083 B CN108992083 B CN 108992083B
- Authority
- CN
- China
- Prior art keywords
- die body
- image
- nested
- internal layer
- projection image
- 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.)
- Active
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
- A61B6/02—Devices for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
- A61B6/03—Computerised tomographs
- A61B6/032—Transmission computed tomography [CT]
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
- A61B6/40—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment with arrangements for generating radiation specially adapted for radiation diagnosis
- A61B6/4064—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment with 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 for radiation diagnosis, e.g. combined with radiation therapy equipment
- A61B6/46—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment with special arrangements for interfacing with the operator or the patient
- A61B6/461—Displaying means of special interest
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
- A61B6/52—Devices using data or image processing specially adapted for radiation diagnosis
- A61B6/5211—Devices using data or image processing specially adapted for radiation diagnosis involving processing of medical diagnostic data
- A61B6/5217—Devices using data or image processing specially adapted for radiation diagnosis involving processing of medical diagnostic data extracting a diagnostic or physiological parameter from medical diagnostic data
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
- A61B6/58—Testing, adjusting or calibrating apparatus or devices for radiation diagnosis
- A61B6/582—Calibration
Abstract
This application involves a kind of cone beam computed tomography method for correcting image and systems.The described method includes: carrying out circular scanning to nested die body, internal layer die body and gas medium respectively, and obtain nested phantom projection image, internal layer phantom projection image and background projection image, multipotency curve is obtained according to nested phantom projection image, internal layer phantom projection image and background projection image data for projection, according to multipotency curve acquisition list energy curve, according to multipotency curve and single energy curve, corrects projected image to be corrected and generate target cone beam computed tomography image.The volume with size of interior layer model are less than nested die body in this method, the lesser data value of length value is obtained according to internal layer phantom projection image, densely obtain the data value of multipotency curve front end portion, improve the accuracy of multipotency curve front end portion, it treats correcting orthographic projection image by the high multipotency curve of front end portion accuracy to be corrected, the accuracy of target cone beam computed tomography image generated is high.
Description
Technical field
This application involves Computed tomography fields, more particularly to a kind of cone beam computed tomography image
Bearing calibration, cone beam computed tomography image correction system, computer equipment and storage medium.
Background technique
Cone beam computed tomography (Cone Beam Computed Tomography, CT) is due to scanning speed
Fastly, the advantages that radiation utilization rate is high and at low cost, is widely used in medical diagnosis and therapy field.Due to the multipotency meeting of ray
Cause to contain artifact phenomenon in cone beam computed tomography image, this artifact phenomenon is known as beam hardening effect, cone of influence
The quality of beam computerized tomographic imaging image.
In order to correct artifact phenomenon, can be put it into the prior art using the uniform die body of cylinder as correction model body
Within the scope of imaging region, so that in the cone beam computed tomography image reconstructed, the outer profile comprising entire cylinder is utilized
The scan geometry parameter and forward projection algorithm of cone beam computed tomography system can simulation calculation go out different rays and wear
Cross cylinder die body length value and find it is right in the cylindrical wire integration data scanned in cone beam computed tomography system
The line integral value answered fits multipotency curve and single energy curve by length value and corresponding line integral value；To other objects into
When row scanning, so that it may multipotency line integral value be transformed to single energy line product using the corresponding relationship of multipotency curve and single energy curve
Score value completes hardening correcting, and the data after recycling correction carry out cone beam computed tomography image reconstruction, obtains no hardening
The CT image of artifact.
But the multipotency curve front end portion data that existing method is fitted are very few, multipotency curve front end portion data vulnerable to
Influence of noise, so that the accuracy that will lead to the front end portion of multipotency curve is low.
Summary of the invention
Based on this, it is necessary to for the accuracy low technical problem of the front end portion of above-mentioned multipotency curve, provide a kind of cone
Beam computerized tomographic imaging method for correcting image and system.
A kind of cone beam computed tomography method for correcting image, comprising the following steps:
Respectively to nested die body, internal layer die body and gas medium carry out circular scanning, and obtain nested phantom projection image,
Internal layer phantom projection image and background projection image, wherein nested die body is the outer layer die body die body set nested with internal layer die body
Part, nested die body are placed in the imaging visible area in the Pivot axle of circular scanning, and internal layer die body is placed on imaging can
In viewed area；
It is bent that multipotency is obtained according to nested phantom projection image, internal layer phantom projection image and background projection image data for projection
Line, according to multipotency curve acquisition list energy curve, wherein multipotency curve is used to indicate the relationship of multipotency line integral value and length value,
Single energy curve is used to indicate the relationship of single energy line integrated value and length value；
According to multipotency curve and single energy curve, corrects projected image to be corrected and generate target cone beam computed tomography
Image.
In one embodiment, circular scanning is carried out to nested die body, internal layer die body and gas medium respectively, and obtained embedding
The step of covering die body projected image, internal layer phantom projection image and background projection image, comprising the following steps:
It controls detector and circular scanning is carried out to nested die body respectively in each predeterminated position, and obtain nested die body each
The projected image of predeterminated position splices nested die body in the projected image of each predeterminated position and obtains nested phantom projection
Image, wherein predeterminated position is used for so that detector keeps continuous in the search coverage of each predeterminated position；
It controls detector and circular scanning is carried out to internal layer die body respectively in each predeterminated position, and obtain internal layer die body each pre-
If the projected image of position, internal layer die body is spliced in the projected image of each predeterminated position and obtains internal layer phantom projection figure
Picture；
It controls detector and circular scanning is carried out to gas medium respectively in each predeterminated position, and obtain gas medium each pre-
If the projected image of position splices gas medium in the projected image of each predeterminated position and obtains background projection image.
In one embodiment, cone beam computed tomography method for correcting image, further comprising the steps of:
According toObtain the diameter of imaging visible area, wherein L=Lsensor+Ladd, D is
Be imaged visible area diameter, SAD be radiographic source at a distance from Pivot axle, SDD be radiographic source it is vertical with detector away from
From, total length of the L for nested phantom projection image institute search coverage, LsensorFor the length of the detectable area of detector, Ladd
For the length of the extension search coverage of detector.
In one embodiment, the number of predeterminated position is at least [Ladd/Lsensor]+1, wherein [] is the symbol that rounds up
Number.
In one embodiment, the number of predeterminated position is N number of, and the distance being spaced between adjacent predeterminated position is Lstep
=Ladd/ (N-1), wherein N >=[Ladd/Lsensor]+1, [] is the symbol that rounds up, LstepBetween between adjacent predeterminated position
Every distance, N is positive integer.
In one embodiment, it is thrown according to nested phantom projection image, internal layer phantom projection image and background projection image
The step of shadow data acquisition multipotency curve, comprising the following steps:
According to the line integral data for projection of nested phantom projection image die body nested with background projection image acquisition, according to embedding
The line integral data for projection for covering die body establishes the middle layer computer tomography image of nested die body, in the centre of nested die body
Layer computer tomography image segmentation goes out the region of nested die body and generates point domain computer tomography figure of nested die body
Picture divides domain computer tomography image to obtain first corresponding first length value of each detection in detector according to nested die body
First Line integrated value corresponding with the first length value；
The line integral data for projection that internal layer die body is obtained according to internal layer phantom projection image and background projection image, according to interior
The line integral data for projection of layer die body establishes the middle layer computer tomography image of internal layer die body, in the centre of internal layer die body
Layer computer tomography image segmentation goes out the region of internal layer die body and generates point domain computer tomography figure of internal layer die body
Picture divides domain computer tomography image to obtain first corresponding second length value of each detection in detector according to internal layer die body
The second line integral value corresponding with the second length value；
It is fitted according to the first length value, First Line integrated value, the second length value and the second line integral value and obtains multipotency song
Line.
In one embodiment, nested die body shape is cylinder, and internal layer die body shape is triangular prism.
A kind of cone beam computed tomography image correction system, comprising:
Projected image obtains module, for carrying out circular scanning to nested die body, internal layer die body and gas medium respectively, and
Obtain nested phantom projection image, internal layer phantom projection image and background projection image, wherein nested die body be outer layer die body and
The die body external member of internal layer die body nesting, nested die body are placed in the imaging visible area in the Pivot axle of circular scanning,
Internal layer die body is placed in imaging visible area；
Multipotency curve acquisition module, for according to nested phantom projection image, internal layer phantom projection image and background plane
Image projection data obtains multipotency curve, according to multipotency curve acquisition list energy curve, wherein multipotency curve is for indicating multipotency line
The relationship of integrated value and length value, single energy curve are used to indicate the relationship of single energy line integrated value and length value；
Projection image correction module to be corrected, for correcting projected image to be corrected according to multipotency curve and single energy curve
And generate target cone beam computed tomography image.
A kind of computer equipment can be run on a memory and on a processor including memory, processor and storage
Computer program, processor perform the steps of when executing computer program
Respectively to nested die body, internal layer die body and gas medium carry out circular scanning, and obtain nested phantom projection image,
Internal layer phantom projection image and background projection image, wherein nested die body is the outer layer die body die body set nested with internal layer die body
Part, nested die body are placed in the imaging visible area in the Pivot axle of circular scanning, and internal layer die body is placed on imaging can
In viewed area；
It is bent that multipotency is obtained according to nested phantom projection image, internal layer phantom projection image and background projection image data for projection
Line, according to multipotency curve acquisition list energy curve, wherein multipotency curve is used to indicate the relationship of multipotency line integral value and length value,
Single energy curve is used to indicate the relationship of single energy line integrated value and length value；
According to multipotency curve and single energy curve, corrects projected image to be corrected and generate target cone beam computed tomography
Image.
A kind of computer readable storage medium is stored thereon with computer program, when computer program is executed by processor
It performs the steps of
Respectively to nested die body, internal layer die body and gas medium carry out circular scanning, and obtain nested phantom projection image,
Internal layer phantom projection image and background projection image, wherein nested die body is the outer layer die body die body set nested with internal layer die body
Part, nested die body are placed in the imaging visible area in the Pivot axle of circular scanning, and internal layer die body is placed on imaging can
In viewed area；
It is bent that multipotency is obtained according to nested phantom projection image, internal layer phantom projection image and background projection image data for projection
Line, according to multipotency curve acquisition list energy curve, wherein multipotency curve is used to indicate the relationship of multipotency line integral value and length value,
Single energy curve is used to indicate the relationship of single energy line integrated value and length value；
According to multipotency curve and single energy curve, corrects projected image to be corrected and generate target cone beam computed tomography
Image.
Above-mentioned cone beam computed tomography method for correcting image and system, the volume of interior layer model are less than nested with size
Die body can obtain the lesser data value of length value according to internal layer phantom projection image, bent convenient for more densely obtaining multipotency
The data value of line front end part is high by front end portion accuracy in order to improve the accuracy of multipotency curve front end portion
Multipotency curve is treated correcting orthographic projection image and is corrected, the accuracy of target cone beam computed tomography image generated
It is high.
Detailed description of the invention
Fig. 1 is the applied environment figure of cone beam computed tomography method for correcting image in one embodiment；
Fig. 2 is the flow chart of cone beam computed tomography method for correcting image in one embodiment；
Fig. 3 is the flow chart of cone beam computed tomography method for correcting image in another embodiment；
Fig. 4 is that CBCT system scans top view in another embodiment；
Fig. 5 is nested die body structural schematic diagram in another embodiment；
Fig. 6 is projection splicing schematic illustration in another embodiment；
Fig. 7 is matched curve schematic diagram in another embodiment；
Fig. 8 is the structural schematic diagram of cone beam computed tomography image correction system in one embodiment；
Fig. 9 is the internal structure chart of computer equipment in one embodiment.
Specific embodiment
It is with reference to the accompanying drawings and embodiments, right in order to which the objects, technical solutions and advantages of the application are more clearly understood
The application is further elaborated.It should be appreciated that specific embodiment described herein is only used to explain the application, not
For limiting the application.
Cone beam computed tomography method for correcting image provided by the present application, can be applied to cone-beam as shown in Figure 1
In computed tomography imaging system, Fig. 1 is the application ring of cone beam computed tomography method for correcting image in one embodiment
Border figure.In cone beam computed tomography system shown in FIG. 1, detector 10 is located at the irradiation of the central ray 22 of radiographic source 21
On direction, detector 10 can be used for detecting and generating image, LsensorFor the length of the detectable area of detector, LaddTo visit
The length of the extension search coverage of device is surveyed, L is the total length of cone beam computed tomography system detectable area, detector 10
Vertical range with radiographic source 21 is SDD, and Pivot axle O is located on SDD, and Pivot axle O is at a distance from radiographic source 21
SAD, cone beam computed tomography system form imaging visible area 30 at Pivot axle O, and imaging visible area 30 can
With for placing nested die body, internal layer die body or object under test, the diameter of imaging visible area 30 is D.Detector shown in FIG. 1
Specific location, detector detectable area length and cone beam computed tomography system detectable area length only
It is intended to illustrate, is not especially limited.
In one embodiment, as shown in Fig. 2, Fig. 2 is cone beam computed tomography image rectification in one embodiment
The flow chart of method provides a kind of cone beam computed tomography method for correcting image, the cone being applied in Fig. 1 in this way
It is illustrated for beam computerized computed tomography (SPECT) system, comprising the following steps:
Step S210: circular scanning is carried out to nested die body, internal layer die body and gas medium respectively, and obtains nested die body
Projected image, internal layer phantom projection image and background projection image, wherein nested die body is that outer layer die body is nested with internal layer die body
Die body external member, nested die body is placed in the imaging visible area in the Pivot axle of circular scanning, and internal layer die body is placed
In imaging visible area.
Circular scanning is carried out to nested die body, obtains nested phantom projection image；Circular scanning is carried out to internal layer die body, is obtained
Take internal layer phantom projection image；Circular scanning is carried out to gas medium, obtains background projection image.
Nested die body and internal layer die body are the die bodys with matching relationship, include internal layer die body in nested die body, nested
Die body is less than nested die body with size by the removal available internal layer die body of outer layer die body, the volume of interior layer model.Nested mould
Body can be the shape of cylinder and internal layer die body is the shape of triangular prism.Nested die body and internal layer die body are also possible to other cylinders
With the combination of rib body.The material of nested die body and internal layer die body can be homogeneous substance, and homogeneous substance can be selected as equivalent water
Substance or pmma material etc..And nested die body can be combined by outer layer die body and internal layer die body, and it can be by body
The biggish nested die body of product has multiple lesser die bodys to be combined to obtain, and can be convenient the carrying and storage of nested die body.
Circular scanning is carried out in imaging visible area and obtains nested phantom projection image for example, nested die body is placed on
Afterwards, the outer layer die body of nested die body can be taken away, leaves internal layer die body and continues circular scanning in imaging visible area
And obtain internal layer phantom projection image.
It is illustrated by taking the circular scanning of nested die body as an example, detector is located at the one of cone beam computed tomography system
The nested die body of side, X-ray bulb and detector in Pivot axle carries out circular scanning, and source focal spot is located at X-ray
Bulb, detector can be used for detecting X-ray bulb and issue X-ray, and X-ray bulb issues X-ray across embedding after every 1 ° of rotation
Set die body is attenuated a part, and remaining X-ray is detected by detector, forms the nested phantom projection image under the angle.If
The emission source of other rays or light also can be used to other rays of detection or light is applied in detector.
Gas medium be carry out above-mentioned circular scanning when nesting die body and internal layer die body at atmosphere.Gas medium
It can be the required atmosphere under imaging circumstances, for example, it may be air, rare gas, nitrogen, a certain proportion of mixed
Close gas, ionic steam, certain pressure intensity or temperature gas.Needs are such as imaged in vacuum environment, the state of gas medium can also
To replace with the state of no gas medium, to form vacuum environment.
Step S220: according to nested phantom projection image, internal layer phantom projection image and background projection image data for projection
Multipotency curve is obtained, according to multipotency curve acquisition list energy curve, wherein multipotency curve is for indicating multipotency line integral value and length
The relationship of value, single energy curve are used to indicate the relationship of single energy line integrated value and length value.
The volume of interior layer model and size are less than nested die body, according to internal layer phantom projection image can obtain length value compared with
Small data value, convenient for more densely obtaining the data value of multipotency curve front end portion, in order to improve multipotency curve front end
Partial accuracy.
Step S230: it according to multipotency curve and single energy curve, corrects projected image to be corrected and generates the calculating of target cone-beam
Machine tomographic imaging image.
The volume of above-mentioned cone beam computed tomography method for correcting image, interior layer model is less than nested die body with size,
The lesser data value of length value can be obtained according to internal layer phantom projection image, convenient for more densely obtaining multipotency curve front end
Partial data value, it is bent by the high multipotency of front end portion accuracy in order to improve the accuracy of multipotency curve front end portion
Line is treated correcting orthographic projection image and is corrected, and the accuracy of target cone beam computed tomography image generated is high.
In one embodiment, circular scanning is carried out to nested die body, internal layer die body and gas medium respectively, and obtained embedding
The step of covering die body projected image, internal layer phantom projection image and background projection image, comprising the following steps:
It controls detector and circular scanning is carried out to nested die body respectively in each predeterminated position, and obtain nested die body each
The projected image of predeterminated position splices nested die body in the projected image of each predeterminated position and obtains nested phantom projection
Image, wherein predeterminated position is used for so that detector keeps continuous in the search coverage of each predeterminated position.
In this step, the length of the detectable area of detector is less than cone beam computed tomography system detectable area
Length, by control detector detected on each predeterminated position, detecting area of the detector on each predeterminated position
Domain is stitched together search coverage length achieved, can be with the length phase of cone beam computed tomography system detectable area
It is together or even longer, it can satisfy the detection that single or a small amount of detector completes longer search coverage, can be effectively reduced into
This, while increasing investigative range and quality.Moreover, control detector carries out circumference to nested die body respectively in each predeterminated position
Scanning, the areas imaging of the nested phantom projection image obtained after splicing is larger, can be conducive to long in subsequent multipotency curve
The longer data value of angle value obtains more data values of multipotency curve rear end part, for being fitted the data of multipotency curve
It is bigger to be worth range, in order to obtain the higher multipotency curve of accuracy after being fitted.In addition, by each predeterminated position respectively to embedding
It covers die body and carries out circular scanning, increase areas imaging, correspondingly, the radius that visible area is imaged also can correspondingly increase,
So that cone beam computed tomography method for correcting image and cone beam computed tomography system can be adapted for volume and ruler
Very little bigger nested die body, internal layer die body and object under test.
It controls detector and circular scanning is carried out to internal layer die body respectively in each predeterminated position, and obtain internal layer die body each pre-
If the projected image of position, internal layer die body is spliced in the projected image of each predeterminated position and obtains internal layer phantom projection figure
Picture.
In this step, the volume of interior layer model is less than nested die body with size, may be easy to obtain the lesser number of length value
According to value, the accuracy of multipotency curve front end portion is improved.
It controls detector and circular scanning is carried out to gas medium respectively in each predeterminated position, and obtain gas medium each pre-
If the projected image of position splices gas medium in the projected image of each predeterminated position and obtains background projection image.
Above-mentioned cone beam computed tomography method for correcting image is carried out by control detector in each predeterminated position respectively
Circular scanning can obviously expand cone beam computed tomography method for correcting image and cone beam computed tomography system
Investigative range, while the data value of greater depth range can be obtained, obtain the multipotency curve that fit range more lengthens, Ke Yizeng
Add the accuracy of energy curve.
In one embodiment, cone beam computed tomography method for correcting image, further comprising the steps of:
According toObtain the diameter of imaging visible area, wherein L=Lsensor+Ladd, D is
Be imaged visible area diameter, SAD be radiographic source at a distance from Pivot axle, SDD be radiographic source it is vertical with detector away from
From, total length of the L for nested phantom projection image institute search coverage, LsensorFor the length of the detectable area of detector, Ladd
For the length of the extension search coverage of detector.
Above-mentioned cone beam computed tomography method for correcting image can rapidly obtain the diameter of imaging visible area,
It can also significantly know and circular scanning is carried out in each predeterminated position by control detector respectively, imaging visible area can be expanded
The diameter and range in domain carry out circumference in order to meet volume with larger-sized nested die body, internal layer die body and object under test
Scanning, improves the efficiency and accuracy of cone beam computed tomography method for correcting image, and does not need used in increase
Detector quantity or the negligible amounts for using detector, can reduce cost.
In addition, if L is greater than twice of Lsensor, two detectors also can be used and visited on multiple predeterminated positions
It surveys, in order to complete detecting to the search coverage of total length.
In one embodiment, the number of predeterminated position is at least [Ladd/Lsensor]+1, wherein [] is the symbol that rounds up
Number.
The number of above-mentioned cone beam computed tomography method for correcting image, predeterminated position is at least [Ladd/Lsensor]+1,
Ensure to complete the detection of larger search coverage with detector, the projected image of each predeterminated position after guaranteeing detection can correspond to
Spliced in institute's detecting location, avoid the occurrence of the missing in gap, in order to improve nested phantom projection image, internal layer die body is thrown
The accuracy of shadow image and background projection image, to improve the accuracy of multipotency curve.
In one embodiment, the number of predeterminated position is N number of, and the distance being spaced between adjacent predeterminated position is Lstep
=Ladd/ (N-1), wherein N >=[Ladd/Lsensor]+1, [] is the symbol that rounds up, LstepBetween between adjacent predeterminated position
Every distance, N is positive integer.
Above-mentioned cone beam computed tomography method for correcting image, predeterminated position can be evenly spaced distribution, convenient for visiting
The projected image of each predeterminated position after survey is simply spliced, and improves the efficiency of splicing, and reduce error rate.
In one embodiment, it is thrown according to nested phantom projection image, internal layer phantom projection image and background projection image
The step of shadow data acquisition multipotency curve, comprising the following steps:
According to the line integral data for projection of nested phantom projection image die body nested with background projection image acquisition, according to embedding
The line integral data for projection for covering die body establishes the middle layer computer tomography image of nested die body, in the centre of nested die body
Layer computer tomography image segmentation goes out the region of nested die body and generates point domain computer tomography figure of nested die body
Picture divides domain computer tomography image to obtain first corresponding first length value of each detection in detector according to nested die body
First Line integrated value corresponding with the first length value.
In this step, in dividing in the computer tomography image of domain for nested die body, the numerical value in the region of nested die body is set
It is set to 1, is set as 0 other than the region of nested die body.According to the geometric parameter of cone beam computed tomography system, a certain
A series of fan-beam x-ray paths are generated using forward projection algorithm simulation under scanning angle.Divide domain computer to nested die body
Tomographic imaging image calculates separately the length that every ray passes through nested die body, and after every ray actually cuts through nested die body
Line integral data for projection can be searched out in the line integral data for projection of nested die body respectively.
The line integral data for projection that internal layer die body is obtained according to internal layer phantom projection image and background projection image, according to interior
The line integral data for projection of layer die body establishes the middle layer computer tomography image of internal layer die body, in the centre of internal layer die body
Layer computer tomography image segmentation goes out the region of internal layer die body and generates point domain computer tomography figure of internal layer die body
Picture divides domain computer tomography image to obtain first corresponding second length value of each detection in detector according to internal layer die body
The second line integral value corresponding with the second length value.
In this step, in dividing in the computer tomography image of domain for internal layer die body, the numerical value in the region of internal layer die body is set
It is set to 1, is set as 0 other than the region of internal layer die body.According to the geometric parameter of cone beam computed tomography system, a certain
A series of fan-beam x-ray paths are generated using forward projection algorithm simulation under scanning angle.Divide domain computer to internal layer die body
Tomographic imaging image calculates separately the length that every ray passes through internal layer die body, and after every ray actually cuts through internal layer die body
Line integral data for projection can be searched out in the line integral data for projection of internal layer die body respectively.
It is fitted according to the first length value, First Line integrated value, the second length value and the second line integral value and obtains multipotency song
Line.
In this step, by the first length value and corresponding First Line integrated value and the second length value and corresponding second line
Integrated value carries out curve fitting, and obtains multipotency curve.Origin tangent line is sought to leading to zeroaxial multipotency curve again, this is cut
Line is single energy curve.
Above-mentioned cone beam computed tomography method for correcting image can quickly and easily be fitted to obtain multipotency curve.
In one embodiment, it is cylinder that nested die body, which is shape, and internal layer die body shape is triangular prism.
Above-mentioned cone beam computed tomography method for correcting image, the combination of cylinder and triangular prism is easily disassembled and assembles,
Facilitate the carrying and storage of nested die body and internal layer die body.
In another embodiment, as shown in figure 3, Fig. 3 is cone beam computed tomography image in another embodiment
The flow chart of bearing calibration, the cone beam computed tomography method for correcting image provided in the present embodiment, includes the following steps:
1) it obtains in CBCT (Cone Beam Computed Tomography, cone beam computed tomography) system
System geometric parameter, CBCT system are as shown in Figure 1, comprising: Pivot axle O is SAD, SAD=at a distance from radiographic source 21
The vertical range of 23cm, detector 10 and radiographic source 21 is SDD, SDD=63cm, the length of the detectable area of detector
Lsensor=13cm, wide W=13cm, the matrix that the detection element array on detector is 1024 × 1024, detector detect first size
For 0.127mm × 0.127mm, CT image reconstruction number is 401, and voxel size is 0.2mm × 0.2mm × 0.2mm, CBCT system
Top view of uniting is as shown in Figure 1.
2) diameter of imaging visible area (FOV) is calculated according to system geometric parameter, D is the diameter that visible area is imaged,
Nested die body of the diameter less than D is made as correction model body, nested die body material is homogeneous substance.It should be appreciated that imaging
Visible area is theoretically expansible maximum imaging region, calculation formula are as follows:
Wherein, L=Lsensor+Ladd, D is the diameter that visible area is imaged, SAD be radiographic source and Pivot axle away from
From SDD is the vertical range of radiographic source and detector, total length of the L for nested phantom projection image institute search coverage, Lsensor
For the length of the detectable area of detector, Ladd=43cm is the length of the extension search coverage of detector.The FOV of calculating is straight
Diameter D=18.7cm, as shown in figure 4, Fig. 4 is that CBCT system scans top view in another embodiment.The nested die body of production selects
Being taken as outer layer is the nested combinations that cylindrical body, internal layer are triangular prism.Cylindrical body a height of 10cm, diameter 15cm.The cross of triangular prism
Section is equilateral triangle, and side length 13cm, center is overlapped with cylindrical body axle center.This combination is quick detachable and assembles, die body material
Material be selected as with pmma material similar in water density, as shown in figure 5, Fig. 5 is nested die body structure in another embodiment
Schematic diagram.It is cylinder with internal layer is the nested combination of triangular prism that nested die body, which is outer layer, is also possible to the group of other cylinders Yu rib body
It closes；Homogeneous substance can be selected as substance or pmma material of equivalent water etc..
3) nested die body is put within the scope of the FOV in CBCT system, and the detector in CBCT system is placed in one end,
So that imaging on the detector can see the edge of nested die body.X-ray bulb and detector surround die body circular scanning,
X-ray bulb issues X-ray and is attenuated a part across nested die body after every 1 ° of rotation, and remaining X-ray is detected by detector,
Form the nested phantom projection image under the angle.It is every after a circular scanning, detector is translated to another extreme direction
A distance Lstep=10.75cm is translated N=4 times altogether.LstepLess than or equal to the length L of detectorsensor, and meet Lsensor
+Ladd=N × Lstep.Until detector is moved to the other end, imaging on the detector is again it can be seen that the edge of nested die body
When complete circular scanning after stop continuing to scan on.5 × 360 projected images are thus obtainedN=0,1,2 ...,
359, i=0,1,2 ..., 4.N indicates which projection angle, i indicate which time translation of detector.In addition, scanning mode can also
Think and arrives next angle scanning again after detector has translated under each angle.
4) the outer layer cylinder die body of nested die body is removed into CBCT system, only scans remaining triangular prism die body, obtain 5 ×
360 projected imagesN, with 3) unanimously, scanning mode repeats step 3) for the definition of i.
5) 4) internal layer triangular prism die body in is also removed into CBCT system, empty scanning only is carried out to air, obtains 5 × 360
Projected imageN, with 3) unanimously, scanning mode repeats step 3) for the definition of i.At this point, air is the gas under imaging circumstances
Body atmosphere.
6) utilize image mosaic technology to 5 × 360 perspective views the projected image under same scan angle in step 3)
PictureSpliced, i.e., the projected image under identical n difference i is successively spliced, is obtained complete nested under each angle
Phantom projection image Pnest(n), as shown in fig. 6, Fig. 6 is projection splicing schematic illustration in another embodiment.
7) utilize image mosaic technology to 5 × 360 perspective views the projected image under same scan angle in step 4)
PictureSpliced, connecting method obtains complete internal layer phantom projection image P under each angle with 6)prism(n)。
8) utilize image mosaic technology to 5 × 360 perspective views the projected image under same scan angle in step 5)
PictureSpliced, connecting method obtains complete background projection image P under each angle with 6)air(n)。
9) by background projection image P complete under each angleair(n) respectively with the complete nested mould under corresponding angle
Body projected image Pnest(n) and complete internal layer phantom projection image Pprism(n) make the logarithmic transformation of corresponding pixel value, respectively
It is converted to the line integral data for projection I_nest (n) of nested die body and with the line integral data for projection I_prism (n) of internal layer die body
Formula are as follows:
I_nest (n)=ln (Pair(n)./Pnest(n))
I_prism (n)=ln (Pair(n)./Pprism(n))
Wherein, ln () indicates that the truth of a matter is the logarithm operation of e, the fortune of being divided by of two matrix corresponding position elements of/expression
It calculates.
10) using the line integral data for projection I_nest (n) and I_prism (n) of nested die body and internal layer die body respectively into
Row CT image reconstruction, method for reconstructing are filter back-projection algorithm, respectively obtain the nested die body of 401 512 × 512 sizes and interior
Layer die body CT image chooses the 201st intermediate tomographic image respectively；CT method for reconstructing can choose filter back-projection reconstruction algorithm.
11) it is partitioned among two width respectively using the OTSU maximum between-cluster variance Threshold sementation in image Segmentation Technology
Respective nested die body and internal layer triangular prism die body in layer CT image.Die body subfield value is set as 1, the picture number other than die body
Value is set as 0；Cutting techniques are Threshold segmentation.
12) the CBCT system geometric parameter according to set by 1), 2) He 3) emulates the image after 11) middle segmentation respectively
The scanning process of radiographic source and detector in practical Cone-Beam CT generates a series of fan-beam X-rays using forward projection algorithm simulation
Path.For the CT image after the segmentation of above-mentioned two width, every ray is calculated separately under 0 ° from radiographic source to different detections member lines
On the length of die body that is partitioned into CT image.And every ray actually cut through the line integral data for projection after die body can be with
Respectively in step 9) the line integral data for projection I_nest (n) and I_prism (n) of nested die body and internal layer die body center row
It is searched out in data.CT image after each segmentation calculates separately to obtain 1024 length values, and searches out 1024 projections
Value.All length value is constituted into set d, all projection values are constituted into set I.
13) T data are less than or equal to all projection values in step 12) set I and corresponding length Value Data carries out index
Fitting is greater than T data to all projection values in step 12) set I and corresponding length Value Data carries out 4 order polynomial fittings.
Fitting formula are as follows:
Wherein a, b, c and k0~k4To be fitted obtained coefficient, T value is chosen for the solution of following formula:
Multipotency matched curve poly_curve is obtained, then seeks origin tangent line to zeroaxial multipotency curve is led to, it should
Tangent line is single energy curve mono_line, as shown in fig. 7, Fig. 7 is matched curve schematic diagram in another embodiment；Curve is quasi-
Conjunction method can choose as exponential fitting, fitting of a polynomial and their combination fitting.
14) detector is translated into go back to CBCT system centre position, recycles the same condition of scanning, scan simulated humanbody head
Mould obtains the multipotency line integral value of emulational head model.According to multipotency curve poly_curve and multipotency line integral value, correspondence can be calculated
Length data.According to single energy curve mono_line and calculated length data, the line integral projection value of single energy can be obtained,
To complete the correction of multipotency line integral value.CT image reconstruction is finally carried out, the target cone without hardening artifact after being corrected
Beam computerized tomographic imaging image.
Above-mentioned cone beam computed tomography method for correcting image can effectively solve the fitting of multipotency curve front end and inaccurately ask
Topic；The curve section of fitting is bigger, and the curve of fitting is more accurate；Die body designs nested styles, is easily carried and kept.
It should be understood that although each step in the flow chart of Fig. 2 to 3 is successively shown according to the instruction of arrow,
It is these steps is not that the inevitable sequence according to arrow instruction successively executes.Unless expressly stating otherwise herein, these steps
There is no stringent sequences to limit for rapid execution, these steps can execute in other order.Moreover, in Fig. 2 to 3 at least
A part of step may include that perhaps these sub-steps of multiple stages or stage are not necessarily in same a period of time to multiple sub-steps
Quarter executes completion, but can execute at different times, the execution in these sub-steps or stage be sequentially also not necessarily according to
Secondary progress, but in turn or can replace at least part of the sub-step or stage of other steps or other steps
Ground executes.
In one embodiment, as shown in figure 8, Fig. 8 is cone beam computed tomography image rectification in one embodiment
The structural schematic diagram of system provides a kind of cone beam computed tomography image correction system in the present embodiment, comprising: projection
Image collection module 310, multipotency curve acquisition module 320 and projection image correction module 330 to be corrected, in which:
Projected image obtains module 310, sweeps for carrying out circumference to nested die body, internal layer die body and gas medium respectively
It retouches, and obtains nested phantom projection image, internal layer phantom projection image and background projection image, wherein nested die body is outer layer
The die body die body external member nested with internal layer die body, nested die body are placed on the imaging visible area in the Pivot axle of circular scanning
In domain, internal layer die body is placed in imaging visible area.
Circular scanning is carried out to nested die body, obtains nested phantom projection image；Circular scanning is carried out to internal layer die body, is obtained
Take internal layer phantom projection image；Circular scanning is carried out to gas medium, obtains background projection image.
Nested die body and internal layer die body are the die bodys with matching relationship, include internal layer die body in nested die body, nested
Die body is less than nested die body with size by the removal available internal layer die body of outer layer die body, the volume of interior layer model.Nested mould
Body can be the shape of cylinder and internal layer die body is the shape of triangular prism.Nested die body and internal layer die body are also possible to other cylinders
With the combination of rib body.The material of nested die body and internal layer die body can be homogeneous substance, and homogeneous substance can be selected as equivalent water
Substance or pmma material etc..And nested die body can be combined by outer layer die body and internal layer die body, and it can be by body
The biggish nested die body of product has multiple lesser die bodys to be combined to obtain, and can be convenient the carrying and storage of nested die body.
Circular scanning is carried out in imaging visible area and obtains nested phantom projection image for example, nested die body is placed on
Afterwards, the outer layer die body of nested die body can be taken away, leaves internal layer die body and continues circular scanning in imaging visible area
And obtain internal layer phantom projection image.
It is illustrated by taking the circular scanning of nested die body as an example, detector is located at the one of cone beam computed tomography system
The nested die body of side, X-ray bulb and detector in Pivot axle carries out circular scanning, and source focal spot is located at X-ray
Bulb, detector can be used for detecting X-ray bulb and issue X-ray, and X-ray bulb issues X-ray across embedding after every 1 ° of rotation
Set die body is attenuated a part, and remaining X-ray is detected by detector, forms the nested phantom projection image under the angle.If
The emission source of other rays or light also can be used to other rays of detection or light is applied in detector.
Gas medium be carry out above-mentioned circular scanning when nesting die body and internal layer die body at atmosphere.Gas medium
It can be the required atmosphere under imaging circumstances, for example, it may be air, rare gas, nitrogen, a certain proportion of mixed
Close gas, ionic steam, certain pressure intensity or temperature gas.Needs are such as imaged in vacuum environment, the state of gas medium can also
To replace with the state of no gas medium, to form vacuum environment.
Multipotency curve acquisition module 320, for being thrown according to nested phantom projection image, internal layer phantom projection image and background
Shadow image projection data obtains multipotency curve, according to multipotency curve acquisition list energy curve, wherein multipotency curve is for indicating multipotency
The relationship of line integral value and length value, single energy curve are used to indicate the relationship of single energy line integrated value and length value.
The volume of interior layer model and size are less than nested die body, according to internal layer phantom projection image can obtain length value compared with
Small data value, convenient for more densely obtaining the data value of multipotency curve front end portion, in order to improve multipotency curve front end
Partial accuracy.
Projection image correction module 330 to be corrected, for correcting perspective view to be corrected according to multipotency curve and single energy curve
Picture simultaneously generates target cone beam computed tomography image.
Above-mentioned cone beam computed tomography image correction system, accuracy high multipotency curve in front end portion is to be corrected
Projected image is corrected, and the accuracy of target cone beam computed tomography image generated is high.
Specific restriction about cone beam computed tomography image correction system may refer to above for cone-beam meter
The restriction of calculation machine tomographic imaging method for correcting image, details are not described herein.Above-mentioned cone beam computed tomography image rectification system
Modules in system can be realized fully or partially through software, hardware and combinations thereof.Above-mentioned each module can be in the form of hardware
It is embedded in or independently of the storage that in the processor in computer equipment, can also be stored in a software form in computer equipment
In device, the corresponding operation of the above modules is executed in order to which processor calls.
In one embodiment, a kind of computer equipment is provided, which can be server, internal junction
Composition can using as shown in figure 9, Fig. 9 as the internal structure chart of computer equipment in one embodiment.The computer equipment includes logical
Cross processor, memory and the network interface of system bus connection.Wherein, the processor of the computer equipment is for providing calculating
And control ability.The memory of the computer equipment includes non-volatile memory medium, built-in storage.The non-volatile memories are situated between
Matter is stored with operating system and computer program.The built-in storage is operating system and computer in non-volatile memory medium
The operation of program provides environment.The network interface of the computer equipment is used to communicate with external terminal by network connection.It should
To realize a kind of cone beam computed tomography method for correcting image when computer program is executed by processor.
It will be understood by those skilled in the art that structure shown in Fig. 9, only part relevant to application scheme is tied
The block diagram of structure does not constitute the restriction for the computer equipment being applied thereon to application scheme, specific computer equipment
It may include perhaps combining certain components or with different component layouts than more or fewer components as shown in the figure.
In one embodiment, a kind of computer equipment is provided, including memory, processor and storage are on a memory
And the computer program that can be run on a processor, processor perform the steps of when executing computer program
Respectively to nested die body, internal layer die body and gas medium carry out circular scanning, and obtain nested phantom projection image,
Internal layer phantom projection image and background projection image, wherein nested die body is the outer layer die body die body set nested with internal layer die body
Part, nested die body are placed in the imaging visible area in the Pivot axle of circular scanning, and internal layer die body is placed on imaging can
In viewed area；
It is bent that multipotency is obtained according to nested phantom projection image, internal layer phantom projection image and background projection image data for projection
Line, according to multipotency curve acquisition list energy curve, wherein multipotency curve is used to indicate the relationship of multipotency line integral value and length value,
Single energy curve is used to indicate the relationship of single energy line integrated value and length value；
According to multipotency curve and single energy curve, corrects projected image to be corrected and generate target cone beam computed tomography
Image.
In one embodiment, it is also performed the steps of when processor executes computer program
It controls detector and circular scanning is carried out to nested die body respectively in each predeterminated position, and obtain nested die body each
The projected image of predeterminated position splices nested die body in the projected image of each predeterminated position and obtains nested phantom projection
Image, wherein predeterminated position is used for so that detector keeps continuous in the search coverage of each predeterminated position；Detector is controlled each
Predeterminated position carries out circular scanning to internal layer die body respectively, and obtains internal layer die body in the projected image of each predeterminated position, internally
Layer die body is spliced in the projected image of each predeterminated position and obtains internal layer phantom projection image；Detector is controlled each default
Position carries out circular scanning to gas medium respectively, and obtains gas medium in the projected image of each predeterminated position, is situated between to gas
Matter is spliced in the projected image of each predeterminated position and obtains background projection image.
In one embodiment, it is also performed the steps of when processor executes computer program
According toObtain the diameter of imaging visible area, wherein L=Lsensor+Ladd, D is
Be imaged visible area diameter, SAD be radiographic source at a distance from Pivot axle, SDD be radiographic source it is vertical with detector away from
From, total length of the L for nested phantom projection image institute search coverage, LsensorFor the length of the detectable area of detector, Ladd
For the length of the extension search coverage of detector.
In one embodiment, it is also performed the steps of when processor executes computer program
According to the line integral data for projection of nested phantom projection image die body nested with background projection image acquisition, according to embedding
The line integral data for projection for covering die body establishes the middle layer computer tomography image of nested die body, in the centre of nested die body
Layer computer tomography image segmentation goes out the region of nested die body and generates point domain computer tomography figure of nested die body
Picture divides domain computer tomography image to obtain first corresponding first length value of each detection in detector according to nested die body
First Line integrated value corresponding with the first length value；Internal layer die body is obtained according to internal layer phantom projection image and background projection image
Line integral data for projection, according to the line integral data for projection of internal layer die body establish the middle layer computerized tomography of internal layer die body at
As image, goes out the region of internal layer die body in the middle layer computer tomography image segmentation of internal layer die body and generate internal layer die body
Divide domain computer tomography image, according to internal layer die body divide domain computer tomography image obtain detector in it is each
Corresponding second length value of detection member and the corresponding second line integral value of the second length value；According to the first length value, First Line product
Score value, the second length value and the second line integral value are fitted and obtain multipotency curve.
In one embodiment, a kind of computer readable storage medium is provided, computer program is stored thereon with, is calculated
Machine program performs the steps of when being executed by processor
Respectively to nested die body, internal layer die body and gas medium carry out circular scanning, and obtain nested phantom projection image,
Internal layer phantom projection image and background projection image, wherein nested die body is the outer layer die body die body set nested with internal layer die body
Part, nested die body are placed in the imaging visible area in the Pivot axle of circular scanning, and internal layer die body is placed on imaging can
In viewed area；
It is bent that multipotency is obtained according to nested phantom projection image, internal layer phantom projection image and background projection image data for projection
Line, according to multipotency curve acquisition list energy curve, wherein multipotency curve is used to indicate the relationship of multipotency line integral value and length value,
Single energy curve is used to indicate the relationship of single energy line integrated value and length value；
According to multipotency curve and single energy curve, corrects projected image to be corrected and generate target cone beam computed tomography
Image.
In one embodiment, it is also performed the steps of when computer program is executed by processor
It controls detector and circular scanning is carried out to nested die body respectively in each predeterminated position, and obtain nested die body each
The projected image of predeterminated position splices nested die body in the projected image of each predeterminated position and obtains nested phantom projection
Image, wherein predeterminated position is used for so that detector keeps continuous in the search coverage of each predeterminated position；Detector is controlled each
Predeterminated position carries out circular scanning to internal layer die body respectively, and obtains internal layer die body in the projected image of each predeterminated position, internally
Layer die body is spliced in the projected image of each predeterminated position and obtains internal layer phantom projection image；Detector is controlled each default
Position carries out circular scanning to gas medium respectively, and obtains gas medium in the projected image of each predeterminated position, is situated between to gas
Matter is spliced in the projected image of each predeterminated position and obtains background projection image.
In one embodiment, it is also performed the steps of when computer program is executed by processor
According toObtain the diameter of imaging visible area, wherein L=Lsensor+Ladd, D is
Be imaged visible area diameter, SAD be radiographic source at a distance from Pivot axle, SDD be radiographic source it is vertical with detector away from
From, total length of the L for nested phantom projection image institute search coverage, LsensorFor the length of the detectable area of detector, Ladd
For the length of the extension search coverage of detector.
In one embodiment, it is also performed the steps of when computer program is executed by processor
According to the line integral data for projection of nested phantom projection image die body nested with background projection image acquisition, according to embedding
The line integral data for projection for covering die body establishes the middle layer computer tomography image of nested die body, in the centre of nested die body
Layer computer tomography image segmentation goes out the region of nested die body and generates point domain computer tomography figure of nested die body
Picture divides domain computer tomography image to obtain first corresponding first length value of each detection in detector according to nested die body
First Line integrated value corresponding with the first length value；Internal layer die body is obtained according to internal layer phantom projection image and background projection image
Line integral data for projection, according to the line integral data for projection of internal layer die body establish the middle layer computerized tomography of internal layer die body at
As image, goes out the region of internal layer die body in the middle layer computer tomography image segmentation of internal layer die body and generate internal layer die body
Divide domain computer tomography image, according to internal layer die body divide domain computer tomography image obtain detector in it is each
Corresponding second length value of detection member and the corresponding second line integral value of the second length value；According to the first length value, First Line product
Score value, the second length value and the second line integral value are fitted and obtain multipotency curve.
Those of ordinary skill in the art will appreciate that realizing all or part of the process in above-described embodiment method, being can be with
Relevant hardware is instructed to complete by computer program, the computer program can be stored in a non-volatile computer
In read/write memory medium, the computer program is when being executed, it may include such as the process of the embodiment of above-mentioned each method.Wherein,
To any reference of memory, storage, database or other media used in each embodiment provided herein,
Including non-volatile and/or volatile memory.Nonvolatile memory may include read-only memory (ROM), programming ROM
(PROM), electrically programmable ROM (EPROM), electrically erasable ROM (EEPROM) or flash memory.Volatile memory may include
Random access memory (RAM) or external cache.By way of illustration and not limitation, RAM is available in many forms,
Such as static state RAM (SRAM), dynamic ram (DRAM), synchronous dram (SDRAM), double data rate sdram (DDRSDRAM), enhancing
Type SDRAM (ESDRAM), synchronization link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM
(RDRAM), direct memory bus dynamic ram (DRDRAM) and memory bus dynamic ram (RDRAM) etc..
Each technical characteristic of above embodiments can be combined arbitrarily, for simplicity of description, not to above-described embodiment
In each technical characteristic it is all possible combination be all described, as long as however, the combination of these technical characteristics be not present lance
Shield all should be considered as described in this specification.
The several embodiments of the application above described embodiment only expresses, the description thereof is more specific and detailed, but simultaneously
It cannot therefore be construed as limiting the scope of the patent.It should be pointed out that coming for those of ordinary skill in the art
It says, without departing from the concept of this application, various modifications and improvements can be made, these belong to the protection of the application
Range.Therefore, the scope of protection shall be subject to the appended claims for the application patent.
Claims (10)
1. a kind of cone beam computed tomography method for correcting image, which comprises the following steps:
Circular scanning is carried out to nested die body, internal layer die body and gas medium respectively, and obtains nested phantom projection image, internal layer
Phantom projection image and background projection image, wherein the nesting die body is the outer layer die body mould nested with the internal layer die body
Body external member, the nesting die body are placed in the imaging visible area in the Pivot axle of circular scanning, the internal layer die body
It is placed in the imaging visible area；
It is obtained according to the nested phantom projection image, the internal layer phantom projection image and the background projection image data for projection
Multipotency curve is taken, according to the multipotency curve acquisition list energy curve, wherein the multipotency curve is for indicating multipotency line integral value
With the relationship of length value, single energy curve is used to indicate the relationship of single energy line integrated value and length value；
According to the multipotency curve and single energy curve, corrects projected image to be corrected and generate target cone-beam computer tomography
Image.
2. cone beam computed tomography method for correcting image according to claim 1, which is characterized in that described right respectively
Nested die body, internal layer die body and gas medium carry out circular scanning, and obtain nested phantom projection image, internal layer phantom projection figure
The step of picture and background projection image, comprising the following steps:
It controls detector and circular scanning is carried out to the nested die body respectively in each predeterminated position, and obtain the nested die body
In the projected image of each predeterminated position, the nested die body is spliced simultaneously in the projected image of each predeterminated position
Obtain the nested phantom projection image, wherein the predeterminated position is used for so that the detector is in each predeterminated position
Search coverage keep continuous；
It controls the detector and circular scanning is carried out to the internal layer die body respectively in each predeterminated position, and obtain in described
Layer die body each predeterminated position projected image, to the internal layer die body each predeterminated position projected image carry out
Splice and obtains the internal layer phantom projection image；
It controls the detector and circular scanning is carried out to the gas medium respectively in each predeterminated position, and obtain the gas
Body medium each predeterminated position projected image, to the gas medium each predeterminated position projected image carry out
Splice and obtains the background projection image.
3. cone beam computed tomography method for correcting image according to claim 2, which is characterized in that further include following
Step:
According toObtain the diameter of the imaging visible area, wherein L=Lsensor+Ladd, D is institute
State imaging visible area diameter, SAD be radiographic source with the Pivot axle at a distance from, SDD for the radiographic source with it is described
The vertical range of detector, L are the detectable area of the detector and the total length for extending search coverage, LsensorIt is described
The length of the detectable area of detector, LaddFor the length of the extension search coverage of the detector.
4. cone beam computed tomography method for correcting image according to claim 3, which is characterized in that the predeterminated position
Number be at least [Ladd/Lsensor]+1, wherein [] is the symbol that rounds up.
5. cone beam computed tomography method for correcting image according to claim 4, which is characterized in that the predeterminated position
Number be it is N number of, the distance being spaced between adjacent predeterminated position be Lstep=Ladd/ (N-1), wherein N >=[Ladd/Lsensor]
+ 1, [] is the symbol that rounds up, LstepThe distance being spaced between the adjacent predeterminated position, N are positive integer.
6. cone beam computed tomography method for correcting image according to claim 1, which is characterized in that described according to institute
It states nested phantom projection image, the internal layer phantom projection image and the background projection image data for projection and obtains multipotency curve
The step of, comprising the following steps:
Number is projected with the line integral that the background projection image obtains the nested die body according to the nested phantom projection image
According to establishing the middle layer computer tomography figure of the nested die body according to the line integral data for projection of the nested die body
Picture goes out described in region and the generation of the nested die body in the middle layer computer tomography image segmentation of the nested die body
Nested die body divides domain computer tomography image, divides domain computer tomography image to obtain according to the nested die body
First corresponding first length value of each detection and the corresponding First Line integrated value of first length value in detector；Wherein, institute
Stating the first length value is the length value that ray passes through the nested die body；
Number is projected according to the line integral that the internal layer phantom projection image and the background projection image obtain the internal layer die body
According to establishing the middle layer computer tomography figure of the internal layer die body according to the line integral data for projection of the internal layer die body
Picture goes out described in region and the generation of the internal layer die body in the middle layer computer tomography image segmentation of the internal layer die body
Internal layer die body divides domain computer tomography image, divides domain computer tomography image to obtain according to the internal layer die body
First corresponding second length value of each detection and the corresponding second line integral value of second length value in the detector；Its
In, second length value is the length value that ray passes through the internal layer die body；
It is fitted according to first length value, the First Line integrated value, second length value and the second line integral value
And obtain the multipotency curve.
7. existing according to claim 1 to cone beam computed tomography method for correcting image, feature described in 6 any one
In the nesting die body shape is cylinder, and the internal layer die body shape is triangular prism.
8. a kind of cone beam computed tomography image correction system, which is characterized in that the system comprises:
Projected image obtains module, for carrying out circular scanning to nested die body, internal layer die body and gas medium respectively, and obtains
Nested phantom projection image, internal layer phantom projection image and background projection image, wherein it is described nesting die body be outer layer die body and
The die body external member of the internal layer die body nesting, it is visual that the nesting die body is placed on the imaging in the Pivot axle of circular scanning
In region, the internal layer die body is placed in the imaging visible area；
Multipotency curve acquisition module, for according to the nested phantom projection image, the internal layer phantom projection image and described
Background projection image data for projection obtains multipotency curve, according to the multipotency curve acquisition list energy curve, wherein the multipotency is bent
Line is used to indicate the relationship of multipotency line integral value and length value, and single energy curve is for indicating single energy line integrated value and length value
Relationship；
Projection image correction module to be corrected, for correcting projection to be corrected according to the multipotency curve and single energy curve
Image simultaneously generates target cone beam computed tomography image.
9. a kind of computer equipment including memory, processor and stores the meter that can be run on a memory and on a processor
Calculation machine program, which is characterized in that the processor realizes any one of claims 1 to 7 institute when executing the computer program
The step of cone beam computed tomography method for correcting image stated.
10. a kind of computer readable storage medium, is stored thereon with computer program, which is characterized in that the computer program
Cone beam computed tomography method for correcting image described in any one of claims 1 to 7 is realized when being executed by processor
Step.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810923092.9A CN108992083B (en) | 2018-08-14 | 2018-08-14 | Cone beam computed tomography method for correcting image and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810923092.9A CN108992083B (en) | 2018-08-14 | 2018-08-14 | Cone beam computed tomography method for correcting image and system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108992083A CN108992083A (en) | 2018-12-14 |
| CN108992083B true CN108992083B (en) | 2019-06-28 |
Family
ID=64596597
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810923092.9A Active CN108992083B (en) | 2018-08-14 | 2018-08-14 | Cone beam computed tomography method for correcting image and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108992083B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11335038B2 (en) * | 2019-11-04 | 2022-05-17 | Uih America, Inc. | System and method for computed tomographic imaging |
| CN111553849B (en) * | 2020-03-28 | 2023-03-24 | 中国人民解放军战略支援部队信息工程大学 | Cone beam CT geometric artifact removing method and device based on local feature matching |
| CN112489046B (en) * | 2020-12-25 | 2023-01-31 | 上海深博医疗器械有限公司 | AI auxiliary measurement volume compensation method and device for flexible scanning image |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5473663A (en) * | 1994-09-12 | 1995-12-05 | General Electric Company | Method for evaluating the performance of detectors in a computed tomography system |
| US6000847A (en) * | 1996-07-08 | 1999-12-14 | Cedars-Sinai Medical Center | Regulation technique for densitometric correction |
| CN103559729A (en) * | 2013-11-18 | 2014-02-05 | 首都师范大学 | Method for iterating and reconstructing double-energy-spectrum CT image |
| CN205831813U (en) * | 2016-05-24 | 2016-12-28 | 广州华端科技有限公司 | A kind of cone-beam CT system correction die body |
| CN108051458A (en) * | 2017-11-27 | 2018-05-18 | 首都师范大学 | A kind of X-ray energy spectrum method of estimation based on rational fraction fitting multipotency drop shadow curve |
| CN108109183A (en) * | 2016-11-25 | 2018-06-01 | 上海东软医疗科技有限公司 | Beam hardening correction method and device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7298812B2 (en) * | 2006-03-31 | 2007-11-20 | General Electric Company | Image-based material decomposition |
-
2018
- 2018-08-14 CN CN201810923092.9A patent/CN108992083B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5473663A (en) * | 1994-09-12 | 1995-12-05 | General Electric Company | Method for evaluating the performance of detectors in a computed tomography system |
| US6000847A (en) * | 1996-07-08 | 1999-12-14 | Cedars-Sinai Medical Center | Regulation technique for densitometric correction |
| CN103559729A (en) * | 2013-11-18 | 2014-02-05 | 首都师范大学 | Method for iterating and reconstructing double-energy-spectrum CT image |
| CN205831813U (en) * | 2016-05-24 | 2016-12-28 | 广州华端科技有限公司 | A kind of cone-beam CT system correction die body |
| CN108109183A (en) * | 2016-11-25 | 2018-06-01 | 上海东软医疗科技有限公司 | Beam hardening correction method and device |
| CN108051458A (en) * | 2017-11-27 | 2018-05-18 | 首都师范大学 | A kind of X-ray energy spectrum method of estimation based on rational fraction fitting multipotency drop shadow curve |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108992083A (en) | 2018-12-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8509380B2 (en) | Inverse geometry volume computed tomography systems | |
| CN108992083B (en) | Cone beam computed tomography method for correcting image and system | |
| CN106373165B (en) | Tomography composograph method for reconstructing and system | |
| EP0502187B1 (en) | Parallel processing method and apparatus based on the algebra reconstruction technique for reconstructing a three-dimensional computerized tomography | |
| NL2011005B1 (en) | Method and apparatus for iterative reconstruction. | |
| US8731266B2 (en) | Method and system for correcting artifacts in image reconstruction | |
| US9824467B2 (en) | Iterative image reconstruction | |
| US20110081071A1 (en) | Method and apparatus for reduction of metal artifacts in ct images | |
| JP5133690B2 (en) | Image reconstruction using voxel-dependent interpolation | |
| US9196061B2 (en) | Systems and methods for performing truncation artifact correction | |
| US7747057B2 (en) | Methods and apparatus for BIS correction | |
| US8433119B2 (en) | Extension of the field of view of a computed tomography system in the presence of interfering objects | |
| CN101109719A (en) | Radiation imaging apparatus and radiation imaging method | |
| JP2010223963A (en) | Method and system for inspection of containers | |
| US7916828B1 (en) | Method for image construction | |
| CN109146800B (en) | Cone beam computed tomography method for correcting image and system | |
| Park et al. | A fully GPU-based ray-driven backprojector via a ray-culling scheme with voxel-level parallelization for cone-beam CT reconstruction | |
| US20050175144A1 (en) | Methods and apparatus for artifact reduction in cone beam CT image reconstruction | |
| US9965875B2 (en) | Virtual projection image method | |
| US20060013355A1 (en) | Method for the reconstruction of sectional images from detector measurement data of a tomography device | |
| US9237873B2 (en) | Methods and systems for CT projection domain extrapolation | |
| JP2021511875A (en) | Non-spectral computed tomography (CT) scanner configured to generate spectral volume image data | |
| US10089758B1 (en) | Volume image reconstruction using projection decomposition | |
| CN111956248A (en) | X-ray imaging method, device, equipment and storage medium | |
| US8577113B2 (en) | Image reconstruction for truncated detector array |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |