CN109350865A

CN109350865A - A MRI-guided radiotherapy system imaging quality control phantom

Info

Publication number: CN109350865A
Application number: CN201811420054.8A
Authority: CN
Inventors: 邱建峰; 戎懿; 曹旻松; 陈迢
Original assignee: Taishan University
Current assignee: Taishan University
Priority date: 2018-11-26
Filing date: 2018-11-26
Publication date: 2019-02-19
Anticipated expiration: 2038-11-26
Also published as: CN109350865B; AU2019388593B2; AU2019388593A1; WO2020108459A1

Abstract

The invention discloses a kind of radiotherapy system imagery quality controll body moulds of guided by magnetic resonance, the diameter of first cylindrical-shaped structure and the second cylindrical-shaped structure is 35-45cm, can satisfy the demand of a wide range of interior image checking of dedicated magnetic resonance Radiation Therapy Simulation positioning system.The diameter of first cylindrical-shaped structure and the second cylindrical-shaped structure is 35-45cm, can satisfy the demand of a wide range of interior image checking of dedicated magnetic resonance Radiation Therapy Simulation positioning system.The inner hollow of first part, for wedge block along the axis annular array of the first cylindrical-shaped structure, wedge structure is solid material, is imaged in nuclear magnetic resonance image, for testing magnetic resonance system limiting resolution.Test fluid is full of inside first part.Part III is entity structure, is internally provided with several diameters not equal hole shape slot, test fluid is filled, for testing the spatial resolution of magnetic resonance system.The hollow square cylindrical bodies of second part and Part IV, for testing the geometric distortion of magnetic resonance system in nuclear magnetic resonance image.

Description

A kind of radiotherapy system imagery quality controll body mould of guided by magnetic resonance

Technical field

The invention belongs to a kind of imagings of the radiotherapy system of magnetic resonance field of radiation therapy more particularly to guided by magnetic resonance Quality control volume mould.

Background technique

Magnetic resonance has good soft tissue contrast, while without ionization radiation injury caused by X-ray.It is very suitable to need The patient for carrying out radiation physiotherapy carries out positioning imaging.With the raising of multimodal systems integration technology, magnet and electronics The integration of beam device, Co 60 equipment is gradually realized.More and more integral type magnetic resonance simulation of radiotherapy treatment positioning systems are asked Generation simultaneously puts into clinical application, such as: ViewRay equipment (magnetic field 0.35T+Co 60 system), the MRI-Linac equipment (magnetic field 1.5T 6MV Linac system) and independent positioning large aperture flat bed magnetic resonance system etc..

The magnetic resonance simulation of radiotherapy treatment positioning system of radiotherapy is exclusively used in compared with conventional magnetic resonance imaging system, is had There are the applicability and compatibility of radiotherapy.The hardware configurations such as examination couch, magnet aperture, magnet length and scanning sequence, Unique design is all had on the software configurations such as positioning software, some relevant special imaging parameters occur therewith.And magnetic resonance mould Radiotherapy treatment planning formulation will be directly applied to by drafting a system imaging, and imaging effect and radiological dose have direct relation.

In this case, the quality control and treatment of dedicated magnetic resonance Radiation Therapy Simulation positioning system guarantee test job, right Guarantee in radiation positioning and dosage, is extremely important.Currently, having complete perfect magnetic resonance quality control both at home and abroad System and quality assurance detect body mould, however these detection body moulds are not particularly suited for the matter of dedicated magnetic resonance Radiation Therapy Simulation positioning system Amount detection.Such as: dedicated magnetic resonance Radiation Therapy Simulation positioning system has the imaging region of large aperture (being greater than 60cm), for diameter The common Quality Control body mould of 20cm or so is unable to satisfy the demand of image checking in a wide range of.Secondly, dedicated magnetic resonance Radiation Therapy Simulation The examination couch of positioning system is flat type, and is equipped with special support frame and places various scanning coils, this requires detection body mould Different coil-types can be corresponded to targetedly to be tested.Most of all, the dedicated Radiation Therapy Simulation in part positions magnetic resonance System needs magnet to have opening, passes through convenient for the electron beam of linear accelerator, and this special designing cannot use the inspection of small size Body mould is surveyed to test.

Summary of the invention

For above-mentioned the technical problems existing in the prior art, the object of the present invention is to provide a kind of putting for guided by magnetic resonance Penetrate treatment system imagery quality controll body mould.The body mould can satisfy a wide range of interior of dedicated magnetic resonance Radiation Therapy Simulation positioning system The demand of image checking.

In order to solve the above technical problems, the technical solution of the present invention is as follows:

A kind of radiotherapy system imagery quality controll body mould of guided by magnetic resonance, including four parts, respectively first Point, second part, Part III and Part IV, this four part is tubular structure, first part and Part III composition the One cylindrical-shaped structure, second part and Part IV form the second cylindrical-shaped structure, the first cylindrical-shaped structure and second cylindric Structure is isometrical, and its length ratio is 1:2.5-3.5；The diameter of first cylindrical-shaped structure and the second cylindrical-shaped structure is 35-45cm；

The combinatorial surface of first part and Part III is parallel with the axis of the first cylindrical-shaped structure, and first part is greater than the Three parts；The combinatorial surface of second part and Part IV is parallel with the axis of the first cylindrical-shaped structure, and second part is greater than the 4th Part；

The combinatorial surface of first part and Part III is overlapped with the combinatorial surface of second part and Part IV；

The inner hollow of first part, internal includes several wedge blocks, several wedge blocks are identical, wedge block Along the axis annular array of the first cylindrical-shaped structure, and the tip of wedge block is towards axis；

Part III is entity structure, is internally provided with the not equal cylindrical groove of several diameters, the axis of cylindrical groove and the The axis of one cylindrical-shaped structure is parallel；

Several hollow square cylinders, square cylinder and the second cylinder are provided with inside second part and Part IV The axis of shape structure is arranged in parallel, and several square cylinders are arranged in fenestral fabric；

First part, second part, the outer wall of Part III and Part IV and internal structure are total by that will not generate magnetic The material of vibration signal is made, and this four part is respectively provided with water filling port, to inject test fluid.

The diameter of first cylindrical-shaped structure and the second cylindrical-shaped structure is 35-45cm, can satisfy dedicated magnetic resonance radiotherapy The demand of a wide range of interior image checking of analog location system.

The inner hollow of first part, for wedge block along the axis annular array of the first cylindrical-shaped structure, wedge structure is real Body material, is imaged in nuclear magnetic resonance image, for testing magnetic resonance system limiting resolution.Test fluid is full of in first part Portion.

Part III is entity structure, is internally provided with several diameters not equal hole shape slot, hole shape slot is hollow, fills and surveys Test solution, for testing the spatial resolution of magnetic resonance system.

The hollow square cylindrical bodies of second part and Part IV, cylinder are used for as basic geometry test unit The geometric distortion of magnetic resonance system is tested in nuclear magnetic resonance image.

Preferably, the length of the first cylindrical-shaped structure is 8-12cm, the second cylindrical-shaped structure 35-45cm.

Length is suitable for the magnetic field center length of magnetic resonance imaging.

Preferably, along the direction perpendicular to first part and the combinatorial surface of Part III, first part and Part III Width ratio is 3:1.

Preferably, along the direction perpendicular to second part and the combinatorial surface of Part IV, second part and Part IV Width ratio is 3:1.

Preferably, the angle of the wedge structure is 2 °, and the angle for the ring structure that wedge structure surrounds is 180 °.

The angle for the ring structure that wedge block surrounds is limited to 180 °, is used for test limits resolution ratio.

For measuring modulation transfer function and limiting resolution.

Preferably, the material of the outer wall of first part, second part, Part III and Part IV and internal structure is to have Machine glass or 3D printing material.

Preferably, the side length of the square cylinder is 0.8-1.2cm, wall thickness 0.08-0.12cm.

It is further preferred that the quantity of the square cylinder is 90-120.

Preferably, cross lines mark is provided on the top plate and bottom plate of the body mould and left side plate.For laser Positioning.

It is further preferred that the cross lines mark is by etching or is printed in body mould surface.

Preferably, described that second cylindrical-shaped structure axial centerline is provided with hollow center terminal, center line The material of column and the material of square cylinder are identical.

Preferably, the outside of the body mould is provided with spirit level.With the levelness of adjusting body mould.

It preferably, include the pure water layer or overflow layer of 3cm inside large aperture test body mould.For testing the noise of magnetic resonance Than and the uniformity.

Preferably, test fluid is distilled water, nickel chloride, sodium chloride or cupric sulfate pentahydrate.Also other magnetic resonance are replaced by Standard test liquid.

The invention has the benefit that

Detailed description of the invention

The accompanying drawings constituting a part of this application is used to provide further understanding of the present application, and the application's shows Meaning property embodiment and its explanation are not constituted an undue limitation on the present application for explaining the application.

Fig. 1 is the three-dimensional figure structure schematic representation of body mould of the invention；

Fig. 2 is the three-dimensional figure structure schematic representation of another angle of body mould of the invention；

Fig. 3 is the main view schematic diagram of body mould of the invention；

Fig. 4 is the rearview structural representation of body mould of the invention；

Fig. 5 is the side view figure structure schematic representation of body mould of the invention；

Fig. 6 is the three-dimensional geometry distortion measurement schematic diagram of large aperture test body mould of the invention；

Fig. 7 is that the three-dimensional geometry distortion measurement of large aperture test body mould of the invention shows figure.

Wherein, 1, first part, 2, second part, 3, Part III, 4, Part IV, 5, center terminal, 6, square column Body, 7, cylindrical groove, 8, wedge block.

Specific embodiment

It is noted that following detailed description is all illustrative, it is intended to provide further instruction to the application.Unless another It indicates, all technical and scientific terms used herein has usual with the application person of an ordinary skill in the technical field The identical meanings of understanding.

It should be noted that term used herein above is merely to describe specific embodiment, and be not intended to restricted root According to the illustrative embodiments of the application.As used herein, unless the context clearly indicates otherwise, otherwise singular Also it is intended to include plural form, additionally, it should be understood that, when in the present specification using term "comprising" and/or " packet Include " when, indicate existing characteristics, step, operation, device, component and/or their combination.

As shown in Figure 1 and Figure 5, the radiotherapy system imagery quality controll body mould of a kind of guided by magnetic resonance, including four Point, respectively first part 1, second part 2, Part III 3 and Part IV 4, this four part is tubular structure, and first Point 1 and Part III 3 form the first cylindrical-shaped structure, second part 2 and Part IV 4 form the second cylindrical-shaped structure, first Cylindrical-shaped structure and the second cylindrical-shaped structure are isometrical, and its length ratio is 1:2.5-3.5；First cylindrical-shaped structure and the second cylinder The diameter of shape structure is 35-45cm, and the length of the first cylindrical-shaped structure is 8-12cm, and the length of the second cylindrical-shaped structure is 35- 45cm, to adapt to the magnetic field center length of magnetic resonance imaging.

The combinatorial surface of first part 1 and Part III 3 is parallel with the axis of the first cylindrical-shaped structure, and first part 1 is big In Part III 3, along the direction perpendicular to first part 1 and the combinatorial surface of Part III 3, first part 1 and Part III 3 Width ratio is 3:1.

The combinatorial surface of second part 2 and Part IV 4 is parallel with the axis of the first cylindrical-shaped structure, and second part 2 is greater than Part IV 4；Along the direction perpendicular to second part 2 and the combinatorial surface of Part IV 4, the width of second part 2 and Part IV 4 Degree is than being 3:1.

As shown in Figure 2 and Figure 4, the group of the combinatorial surface of first part 1 and Part III 3 and second part 2 and Part IV 4 Conjunction face is overlapped；The inner hollow of first part 1, internal includes several wedge blocks 8, several wedge blocks 8 are identical, wedge Shape block 8 is along the axis annular array of the first cylindrical-shaped structure, and the tip of wedge block 8 is towards axis；The angle of wedge block 8 is 2 °, the angle for the ring structure that wedge block 8 surrounds is 180 °.The angle for the ring structure that wedge block 8 surrounds is limited to 180 °, uses In test limits resolution ratio.

Part III 3 is entity structure, is internally provided with the not equal cylindrical groove 7 of several diameters, the axis of cylindrical groove 7 with The axis of first cylindrical-shaped structure is parallel；

As shown in figure 3, several hollow square cylinders 6 are provided with inside second part 2 and Part IV 4, it is rectangular Cylinder 6 and the axis of the second cylindrical-shaped structure are arranged in parallel, and several square cylinders are arranged in fenestral fabric；Square cylinder 6 side length is 0.8-1.2cm, wall thickness 0.08-0.12cm.The quantity of square cylinder 6 is 90-120.

First part 1, second part 2, the outer wall of Part III 3 and Part IV 4 and internal structure are by will not generate The material of magnetic resonance signal is made, and this four part is respectively provided with water filling port, to inject test fluid.

The diameter of first cylindrical-shaped structure and the second cylindrical-shaped structure is 35-45cm, can satisfy dedicated magnetic resonance radiotherapy The demand of a wide range of interior image checking of analog location system.The inner hollow of first part, wedge block 8 is along the first cylindric knot The axis annular array of structure, wedge structure are solid material, are imaged in nuclear magnetic resonance image, for testing the magnetic resonance system limit Resolution ratio.Test fluid is full of inside first part.Part III is entity structure, is internally provided with several diameters not equal hole Shape slot, hole shape slot is hollow, test fluid is filled, for testing the spatial resolution of magnetic resonance system.Second part and Part IV Hollow square cylindrical bodies, cylinder is as basic geometry test unit, for testing magnetic resonance system in nuclear magnetic resonance image Geometric distortion.

First part 1, second part 2, Part III 3 and the outer wall of Part IV 4 and the material of internal structure are organic Glass or 3D printing material.

Be provided in the top plate and bottom plate and left side plate of the body mould cross lines mark, be used for laser positioning, ten Font lines mark is by etching or is printed in body mould surface.

The axial centerline of second cylindrical-shaped structure is provided with hollow center terminal, the material of center terminal with it is rectangular The material of cylinder 6 is identical.The outside of the body mould is provided with spirit level, with the levelness of adjusting body mould.

It include the pure water layer or overflow layer of 3cm inside the test body mould of large aperture.For test magnetic resonance signal-to-noise ratio and Evenness.

Test fluid can be the test fluids such as distilled water, nickel chloride, sodium chloride or cupric sulfate pentahydrate.

Large aperture test body mould top half can be individually used for the guided by magnetic resonance radiotherapy system that there is plate to check location bed System uses.It can be used for having the magnetic resonance system of arc examination couch to use after the combination of top and the bottom.

Large aperture test body mould is main that magnetic resonance test solution is perfused in addition to internal entity structure.Test fluid can pass through body The bolt mouth at mould both ends is replaced.

On the magnetic resonance imaging image of body mould, square can be formed in the specific position of cross section, sagittal plane and coronal-plane Battle array grid image (the dark lattice of grid protocol no signal, the bright signal of surrounding test fluid) and point cloud chart are as (grid protocol no signal Dim spot, the bright signal of surrounding test fluid).

Above-mentioned grid column structure is connected in the form of Tenon in grid point of intersection, such as uses 3D printing grid, can be integrated Printing is completed, and is not required to connect.

Above-mentioned network has the center line column structure of overstriking to identify in the position of center line of body mould cylinder, cross-section to be It will form the column grid or dotted image of overstriking on scan image.To identifying body mould physical centre.

It include the pure water layer or overflow layer of 3cm inside large aperture test body mould, for testing the signal-to-noise ratio and of magnetic resonance Evenness.

It include the triangle organic glass or 3D printing material-structure on 45 degree of diagonal slopes, structure inside the test body mould of large aperture There are three groups, it is orthogonally located, for carrying out the test of space orientation accuracy in cross section, sagittal plane and coronal-plane.

It include the organic glass or 3D printing material-structure on 30 degree of long slopes inside the test body mould of large aperture, for testing magnetic Resonance scan thickness and layer deviation.

Contain star-like test structure, specially 2 degree of wedge-shaped organic glass or 3D printing material inside the test body mould of large aperture Matter structure, circumference is placed, for measuring modulation transfer function and limiting resolution.

Test body mould mating 3D digital dot array model in large aperture is stored with software on line and with mould software form.Pass through After DICOM browser or reading graph software are opened, the selection of any level, any FOV may be implemented.The macropore that scanning input obtains Diameter tests phantom image, can be by reading the visual field and matrix information in DICOM file head, by the correspondence of digital dot array model FOV model consubstantiality mould real image is registrated, is merged, and comparison shows practical grid and lattice position and image grid and dot matrix The difference of position, the spatial offset of quantitative analysis corresponding position, and derive appearance deviation.It is aobvious by double-colored display or 3d space Show, geometric distortion caused by intuitive showground deviation.

As shown in Figure 6 and Figure 7, the mating 3D digital processing software of large aperture test body mould, can be on computers by transferring Body mould DICOM sequence image, by information such as thickness, matrixes in automatic identification body mould locating piece and DICOM image, it is automatic really Determine the Quality Control test tomographic image in sequence image.To in Quality Control test layer image aforementioned grid or point cloud signal known automatically , do not determine the mass center or geometric center of grid apex angle or point using projection pattern, at the same determine body mould/picture centre, FOV and away from Image range from center 22.5cm/17.5cm/10cm.Digital processing software automatic measurement & calculation is different apart from body mould/picture centre The point of distance shows the difference on three different directions with unlike signal or color as the difference with actual position.To scheme Sheet form indicates field strength variation or geometric distortion in the FOV of phantom measurement.

3D digital dot array model can calculate the brightness amplitude of body mould water signal, pass through the correspondence of digital dot array model FOV model consubstantiality mould real image is registrated, is merged, and the signal difference of each spatial position in display image is compared with pseudo-colours Signal amplitude and signal-to-noise ratio different, change to compare multi-channel coil with spatial position.

Large aperture test body mould test fluid and internal various structures can the scanning imagery at CT simultaneously, be similarly applied to CT The quality of the radiotherapy system of guidance controls and quality assurance.

The foregoing is merely preferred embodiment of the present application, are not intended to limit this application, for the skill of this field For art personnel, various changes and changes are possible in this application.Within the spirit and principles of this application, made any to repair Change, equivalent replacement, improvement etc., should be included within the scope of protection of this application.

Claims

1. A magnetic resonance guided radiotherapy system imaging quality control phantom, characterized in that: it comprises four parts, which are respectively a first part, a second part, a third part and a fourth part, and these four parts are all cylindrical structures , the first part and the third part form the first cylindrical structure, the second part and the fourth part form the second cylindrical structure, the first cylindrical structure and the second cylindrical structure are equal in diameter, and their length ratio is 1:2.5 -3.5; the diameter of the first cylindrical structure and the second cylindrical structure is 35-45 cm;

The combined surface of the first part and the third part is parallel to the axis of the first cylindrical structure, and the first part is larger than the third part; the combined surface of the second part and the fourth part is parallel to the axis of the first cylindrical structure, and the second part greater than the fourth part;

The combined surface of the first part and the third part coincides with the combined surface of the second part and the fourth part;

The interior of the first part is hollow, and the interior includes several wedge-shaped blocks, the several wedge-shaped blocks are identical, the wedge-shaped blocks are annularly arranged along the axis of the first cylindrical structure, and the tips of the wedge-shaped blocks face the axis;

The third part is a solid structure, and a plurality of cylindrical grooves with different diameters are arranged inside, and the axis of the cylindrical groove is parallel to the axis of the first cylindrical structure;

The second part and the fourth part are provided with several hollow square cylinders, the square cylinders are arranged parallel to the axis of the second cylindrical structure, and the several square cylinders are arranged in a grid-like structure;

The outer walls and internal structures of the first part, the second part, the third part and the fourth part are all made of materials that do not generate magnetic resonance signals, and the four parts are all provided with water injection ports for injecting the test liquid.

2 . The imaging quality control phantom of the magnetic resonance guided radiotherapy system according to claim 1 , wherein the length of the first cylindrical structure is 8-12 cm, and the length of the second cylindrical structure is 35-45 cm. 3 .

3 . The imaging quality control phantom of the magnetic resonance guided radiotherapy system according to claim 1 , wherein: along the direction perpendicular to the combined plane of the first part and the third part, the width ratio of the first part and the third part is 3:1.

4 . The imaging quality control phantom of the magnetic resonance guided radiotherapy system according to claim 1 , wherein: along the direction perpendicular to the combined plane of the second part and the fourth part, the second part and the fourth part have The width ratio is 3:1.

5 . The imaging quality control phantom of the magnetic resonance guided radiotherapy system according to claim 1 , wherein the angle of the wedge-shaped structure is 2°, and the angle of the annular structure enclosed by the wedge-shaped structure is 180°. 6 .

6 . The imaging quality control phantom of the magnetic resonance guided radiotherapy system according to claim 1 , wherein the material of the outer wall and the inner structure of the first part, the second part, the third part and the fourth part is plexiglass. 7 . or 3D printing materials.

7 . The imaging quality control phantom of the magnetic resonance guided radiotherapy system according to claim 1 , wherein the side length of the square column is 0.8-1.2 cm, the wall thickness is 0.08-0.12 cm, and the square column is 0.08-0.12 cm. 8 . The number of bodies is 90-120.

8 . The imaging quality control phantom of a magnetic resonance guided radiotherapy system according to claim 1 , wherein the top plate, the bottom plate and the left and right side plates of the phantom are provided with cross-shaped line marks, and the cross-shaped line The logo is etched or printed on the surface of the phantom.

9 . The imaging quality control phantom of the magnetic resonance guided radiotherapy system according to claim 1 , wherein a hollow centerline column is arranged at the position of the center axis of the second cylindrical structure, and the centerline column is The material is the same as that of the square cylinder.

10 . The imaging quality control phantom of the magnetic resonance guided radiotherapy system according to claim 1 , wherein a bubble-type level is provided outside the phantom. 11 .