Testing device and method for cross image system

Abstract

The invention discloses a testing device and method for a cross image system, and belongs to the technical field of radiotherapy equipment. A testing device for a cross image system comprises two guide rails, the two guide rails are arranged in a cross shape and rotationally connected, a die body testing platform is arranged at the cross position of the two guide rails, the die body testing platform is installed on one guide rail, the die body testing platform is used for placing a die body main body, and the spatial position of the die body testing platform can be adjusted. An X-ray tube support and a flat panel detector support are connected to the guide rail in a sliding mode and located on the two sides of the die body testing platform respectively, the X-ray tube support is used for installing an X-ray tube body, and the installation angle and position of the X-ray tube body on the X-ray tube support can be adjusted. The flat panel detector support is used for installing the flat panel detector body, and the installation angle and position of the flat panel detector body on the flat panel detector support can be adjusted.

Description

Technical Field

[0001] The present invention relates to the technical field of radiotherapy equipment, and more specifically, to a testing device and method for a cross-image system. Background Art

[0002] With the development of medical imaging equipment technology, imaging equipment is used in medical diagnosis and patient treatment. In the application of radiotherapy equipment, medical imaging equipment can be used to locate the patient's tumor site. The cross-imaging system used in the gamma knife radiotherapy equipment adopts cross-angle stereoscopic plane imaging technology. Through computer control of two sets of imaging hardware systems composed of KV-level (diagnostic level) X-ray tube components, high-voltage generators, flat-panel detectors, and exposure controllers, the patient's anatomical structure or external implanted markers are perspectively projected in two directions to obtain a pair of cross-angle X-ray projection images. The obtained two-dimensional X-ray projection images and the three-dimensional CT images used for radiotherapy planning are subjected to 2D-3D image registration and 2D-3D geometric conversion to accurately detect the positioning error of the patient (lesion) on the radiotherapy equipment, and guide the radiotherapy equipment to move the treatment bed, correct the patient's position, and achieve accurate positioning of the patient before treatment. At present, when the cross-imaging system is installed on the gamma knife equipment, it is necessary to ensure the lowest exposure dose while ensuring image quality, because the exposure dose is harmful to the patient.

[0003] After searching, the patent document with the existing publication number CN112914591A provides an image-guided system calibration device and method. This method quickly completes the initial position installation of the flat-panel detector based on the laser beam and the phantom light path, and then realizes the precise positioning of the installation position of the flat-panel detector based on X-rays and markers (metal balls), and finally realizes the confirmation and verification of the final position of the flat-panel detector through alignment.

[0004] The above method is only applicable to calibrating a group of imaging devices, and cannot be applied to calibrating a cross-imaging system. In view of this, we propose a testing device and method for a cross-imaging system. Summary of the invention

[0005] 1. Technical issues to be solved

[0006] The object of the present invention is to provide a testing device and method for a cross-image system to solve the problems raised in the above background technology.

[0007] 2. Technical solution

[0008] The present invention is achieved through the following technical solutions:

[0009] A testing device for a cross-image system comprises two guide rails, which are arranged in a cross shape and are rotatably connected. A phantom test platform is provided at the intersection of the two guide rails, and the phantom test platform is installed on one of the guide rails. The phantom test platform is used to place a phantom body, and the spatial position of the phantom test platform can be adjusted. An X-ray tube bracket and a flat-panel detector bracket are slidably connected to the guide rails, and the X-ray tube bracket and the flat-panel detector bracket are respectively located on both sides of the phantom test platform. The X-ray tube bracket is used to install the X-ray tube body, and the installation angle and position of the X-ray tube body on the X-ray tube bracket are both adjustable. The flat-panel detector bracket is used to install the flat-panel detector body, and the installation angle and position of the flat-panel detector body on the flat-panel detector bracket are both adjustable.

[0010] A testing method for a cross-image system comprises the following steps:

[0011] S1. Install the X-ray tube body on the X-ray tube bracket, install the flat panel detector body on the flat panel detector bracket, and position the X-ray tube body and the flat panel detector body on the guide rail;

[0012] S2, placing the phantom body on the phantom test platform, and adjusting the position of the phantom body;

[0013] S3, according to the initial voltage, current and exposure time parameters of the X-ray tube body, controlling the X-ray tube body to emit a beam and forming a planar image on the flat panel detector body;

[0014] S4, adjusting the distance between the X-ray tube body and the phantom body and the distance between the X-ray tube body and the flat panel detector body to obtain a planar image that meets the first standard, and recording the distance between the X-ray tube body and the phantom body and the distance between the X-ray tube body and the flat panel detector body at this time;

[0015] S5, controlling the two X-ray tube bodies to emit beams, forming a plane image on the two flat panel detector bodies, and generating a three-dimensional phantom model using the two plane images;

[0016] S6, adjusting the angle between the two guide rails to obtain a three-dimensional phantom model that meets the second standard, and recording the angle between the two guide rails at this time;

[0017] S7. Adjust the voltage, current and exposure time parameters of the X-ray tube body within the range allowed by the imaging dose to obtain a three-dimensional phantom model that meets the second standard, and record the voltage, current and exposure time parameters of the X-ray tube body at this time;

[0018] S8. Install and debug the X-ray tube body and the flat-panel detector body according to the recorded distance between the X-ray tube body and the phantom body, the distance between the X-ray tube body and the flat-panel detector body, the angle between the two guide rails, and the voltage, current, and exposure time parameters of the X-ray tube body.

[0019] As an optional solution of the technical solution of this application document, S1 includes the following sub-steps:

[0020] S101, installing a cross laser light at the beam outlet of the X-ray tube body;

[0021] S102, adjusting the flat panel detector body so that the projection of the cross laser light on the flat panel detector body is aligned with the cross mark on the panel of the flat panel detector body.

[0022] As an optional solution of the technical solution of this application document, S2 includes the following sub-steps:

[0023] S201, generating a three-dimensional phantom model of the phantom body by using the plane image projected by the phantom body on the two flat-panel detector bodies, and obtaining the phantom center coordinates of the three-dimensional phantom model;

[0024] S202, obtaining the focal coordinates of the two X-ray tube bodies in the coordinate system where the three-dimensional phantom model is located, and calculating the error distance between the phantom center coordinates and the focal coordinates;

[0025] S203: Adjust the position of the phantom body until the error distance is smaller than a set error threshold.

[0026] As an optional solution of the technical solution of this application document, the error threshold is 0.5mm.

[0027] As an optional solution of the technical solution of the present application document, the distance between the X-ray tube body and the phantom body is 1500mm-2100mm, and the distance between the X-ray tube body and the flat panel detector body is 3000mm.

[0028] As an optional solution of the technical solution of this application document, the angle between the guide rails is 70°-110°.

[0029] As an optional solution of the technical solution of this application document, the voltage is 100KV-140KV.

[0030] As an optional solution of the technical solution of this application document, the current is 100mA-200mA.

[0031] As an optional solution of the technical solution of this application document, the exposure time is 0.05s-0.1s.

[0032] 3. Beneficial effects

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1) The present application can adjust the angle between the two X-ray tube bodies in the cross-imaging system by setting two cross-shaped guide rails, which is used to test the imaging quality of the cross-imaging system at different angles, thereby solving the defect that the prior art can only calibrate one group of imaging equipment.

[0035] 2) This application can obtain the usage parameters of the X-ray tube body and the flat-panel detector body by testing different SAD values, S ID values, θ values, and the voltage value, current value, and exposure time of the X-ray tube body in sequence, and guide the installation and debugging of the X-ray tube body and the flat-panel detector. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the overall structure of a test device for a cross-imaging system;

[0037] Figure 2 It is a schematic diagram of the planar layout structure of the X-ray tube main body of a test device for a cross-image system;

[0038] In the figure: 1. guide rail; 101. X-ray tube bracket; 102. flat panel detector bracket; 103. X-ray tube body; 104. flat panel detector body; 2. phantom test platform; 3. phantom body. DETAILED DESCRIPTION

[0039] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0040] Embodiment 1:

[0041] See also Figure 1 The present invention provides a testing device for a cross imaging system, comprising two guide rails 1, which are arranged in a cross shape and are rotatably connected. A phantom test platform 2 is provided at the intersection of the two guide rails 1, and the phantom test platform 2 is installed on one of the guide rails 1. The phantom test platform 2 is used to place a phantom body 3, and the spatial position of the phantom test platform 2 can be adjusted. An X-ray tube bracket 101 and a flat panel detector bracket 102 are slidably connected to the guide rail 1. The X-ray tube bracket 101 and the flat panel detector bracket 102 are respectively located on both sides of the phantom test platform 2. The X-ray tube bracket 101 is used to install an X-ray tube body 103, and the installation angle and position of the X-ray tube body 103 on the X-ray tube bracket 101 can be adjusted. The flat panel detector bracket 102 is used to install a flat panel detector body 104, and the installation angle and position of the flat panel detector body 104 on the flat panel detector bracket 102 can be adjusted.

[0042] In the present device, the X-ray tube body 103 can be installed through the X-ray tube bracket 101, and the flat panel detector body 104 can be installed through the flat panel detector bracket 102. The distance SAD between the X-ray tube body 103 and the phantom body 3 and the distance S ID between the X-ray tube body 103 and the flat panel detector body 104 can be adjusted by moving the X-ray tube bracket 101 and the flat panel detector bracket 102; the angle θ between the two X-ray tube bodies 103 can be changed by relatively rotating the two guide rails 1; the spatial position of the phantom body 3 in the cross-imaging system can be adjusted through the phantom test platform 2; the user can calibrate different X-ray tube bodies 103 and flat panel detector bodies 104 through the present device, and obtain appropriate SAD values, S ID values, θ values, and voltage values, current values, and exposure time of the X-ray tube body 103, which are used to guide the installation of the X-ray tube body 103 and the flat panel detector body 104.

[0043] Embodiment 2:

[0044] The present application provides a testing method for a cross-image system, which is applied to a testing device for a cross-image system described in Example 1, and includes the following steps:

[0045] S1, installing the X-ray tube body 103 on the X-ray tube bracket 101, installing the flat panel detector body 104 on the flat panel detector bracket 102, and positioning the X-ray tube body 103 and the flat panel detector body 104 on the guide rail 1;

[0046] S2, placing the phantom body 3 on the phantom test platform 2, and adjusting the position of the phantom body 3;

[0047] S3, according to the initial voltage, current and exposure time parameters of the X-ray tube main body 103, controlling the X-ray tube main body 103 to emit a beam, and forming a planar image on the flat panel detector main body 104;

[0048] S4, adjusting the distance between the X-ray tube body 103 and the phantom body 3 and the distance between the X-ray tube body 103 and the flat panel detector body 104 to obtain a planar image that meets the first standard, and recording the distance between the X-ray tube body 103 and the phantom body 3 and the distance between the X-ray tube body 103 and the flat panel detector body 104 at this time;

[0049] S5, controlling the two X-ray tube bodies 103 to emit beams, forming a plane image on the two flat panel detector bodies 104, and generating a three-dimensional phantom model using the two plane images;

[0050] S6, adjusting the angle between the two guide rails 1 to obtain a three-dimensional phantom model that meets the second standard, and recording the angle between the two guide rails 1 at this time;

[0051] S7. Within the range allowed by the imaging dose, the voltage, current and exposure time parameters of the X-ray tube body 103 are adjusted to obtain a three-dimensional phantom model that meets the second standard, and the voltage, current and exposure time parameters of the X-ray tube body 103 are recorded at this time;

[0052] S8. Install and debug the X-ray tube body 103 and the flat panel detector body 104 according to the recorded distance between the X-ray tube body 103 and the phantom body 3, the distance between the X-ray tube body 103 and the flat panel detector body 104, the angle between the two guide rails 1, and the voltage, current and exposure time parameters of the X-ray tube body 103.

[0053] In the above method, both the first standard and the second standard adopt the relevant provisions in National Standard YY1650-2019, National Standard YY1650-2019, and National Standard YY0741-2009.

[0054] S1 includes the following sub-steps:

[0055] S101, installing a cross laser lamp at the beam outlet of the X-ray tube body 103;

[0056] S102 , adjusting the flat panel detector body 104 so that the projection of the cross laser light on the flat panel detector body 104 is aligned with the cross mark on the panel of the flat panel detector body 104 .

[0057] S2 includes the following sub-steps:

[0058] S201, generating a three-dimensional phantom model of the phantom body 3 by using the plane image projected on the two flat panel detector bodies 104, and obtaining the phantom center coordinates of the three-dimensional phantom model;

[0059] S202 , obtaining the focal coordinates of the two X-ray tube bodies 103 in the coordinate system where the three-dimensional phantom model is located, and calculating the error distance between the phantom center coordinates and the focal coordinates.

[0060] S203 , adjusting the position of the phantom body 3 until the error distance is smaller than a set error threshold, the error threshold being 0.5 mm.

[0061] The experimental data obtained by using the above method are as follows:

[0062] Table 1: S ID=3000, SAD / S ID=0.5

[0063]

[0064]

[0065] Table 2: S ID=3000, SAD / S ID=0.6

[0066]

[0067] Table 3: S ID=3000, SAD / S ID=0.7

[0068]

[0069] Among them, the imaging quality A refers to the imaging quality of the three-dimensional phantom model, and the judgment criteria are as follows:

[0070] condition Spatial resolution Contrast resolution Image uniformity Effective imaging area scope ≥2.5lp / mm ≤2.3％ ≤2.5％ ≥95％

[0071] From the above experimental data, it can be seen that the distance between the X-ray tube body 103 and the phantom body 3 is 1500mm-2100mm, the distance between the X-ray tube body 103 and the flat panel detector body 104 is 3000mm, the angle between the guide rails 1 is 70°-110°, the voltage is 100KV-140KV, the current is 100mA-200mA, and the exposure time is 0.05s-0.1s, and a clear three-dimensional phantom model can be obtained.

Claims

1. A test device for a cross-image system, characterized in that: The invention comprises: two guide rails (1), the two guide rails (1) are arranged in a cross shape and are rotatably connected, a phantom test platform (2) is provided at the intersection of the two guide rails (1), the phantom test platform (2) is installed on one of the guide rails (1), the phantom test platform (2) is used to place a phantom body (3), the spatial position of the phantom test platform (2) can be adjusted, an X-ray tube bracket (101) and a flat panel detector bracket (102) are slidably connected to the guide rails (1), and the X-ray tube bracket (101) and the ... The X-ray tube support (101) and the flat-panel detector support (102) are respectively located on both sides of the phantom test platform (2); the X-ray tube support (101) is used to install the X-ray tube body (103); the installation angle and position of the X-ray tube body (103) on the X-ray tube support (101) are both adjustable; the flat-panel detector support (102) is used to install the flat-panel detector body (104); the installation angle and position of the flat-panel detector body (104) on the flat-panel detector support (102) are both adjustable.

2. A test method for a cross-image system, applied to the test device for a cross-image system as claimed in claim 1, characterized in that: The following steps are involved: S1. Installing the X-ray tube body (103) on the X-ray tube support (101), installing the flat panel detector body (104) on the flat panel detector support (102), and positioning the X-ray tube body (103) and the flat panel detector body (104) on the guide rail (1); S2, placing the phantom body (3) on the phantom test platform (2), and adjusting the position of the phantom body (3); S3, controlling the X-ray tube body (103) to emit a beam according to the initial voltage, current and exposure time parameters of the X-ray tube body (103), and forming a planar image on the flat panel detector body (104); S4, adjusting the distance between the X-ray tube body (103) and the phantom body (3) and the distance between the X-ray tube body (103) and the flat panel detector body (104) to obtain a planar image that meets the first standard, and recording the distance between the X-ray tube body (103) and the phantom body (3) and the distance between the X-ray tube body (103) and the flat panel detector body (104) at this time; S5, controlling the two X-ray tube bodies (103) to emit beams, forming a plane image on two flat panel detector bodies (104), and generating a three-dimensional phantom model using the two plane images; S6, adjusting the angle between the two guide rails (1) to obtain a three-dimensional phantom model that meets the second standard, and recording the angle between the two guide rails (1) at this time; S7. Within the range allowed by the imaging dose, the voltage, current and exposure time parameters of the X-ray tube body (103) are adjusted to obtain a three-dimensional phantom model that meets the second standard, and the voltage, current and exposure time parameters of the X-ray tube body (103) are recorded at this time; S8. Install and debug the X-ray tube body (103) and the flat-panel detector body (104) according to the recorded distance between the X-ray tube body (103) and the phantom body (3), the distance between the X-ray tube body (103) and the flat-panel detector body (104), the angle between the two guide rails (1), and the voltage, current, and exposure time parameters of the X-ray tube body (103).

3. A testing method for a cross-image system according to claim 2, characterized in that: The S1 comprises the following sub-steps: S101, installing a cross laser lamp at the beam outlet of the X-ray tube body (103); S102, adjusting the flat panel detector body (104) so ​​that the projection of the cross laser light on the flat panel detector body (104) is aligned with the cross mark on the panel of the flat panel detector body (104).

4. A testing method for a cross-image system according to claim 2, characterized in that: The S2 comprises the following sub-steps: S201, generating a three-dimensional phantom model of the phantom body (3) by using the planar image projected by the phantom body (3) onto the two flat-panel detector bodies (104), and obtaining the phantom center coordinates of the three-dimensional phantom model; S202, obtaining the focal coordinates of two X-ray tube bodies (103) in the coordinate system where the three-dimensional phantom model is located, and calculating the error distance between the phantom center coordinates and the focal coordinates; S203, adjusting the position of the phantom body (3) until the error distance is smaller than a set error threshold.

5. A testing method for a cross-image system according to claim 4, characterized in that: The error threshold is 0.5 mm.

6. A method for testing a cross-image system according to claim 2, characterized in that: The distance between the X-ray tube body (103) and the phantom body (3) is 1500 mm-2100 mm, and the distance between the X-ray tube body (103) and the flat panel detector body (104) is 3000 mm.

7. A testing method for a cross-image system according to claim 2, characterized in that: The included angle between the guide rails (1) is 70°-110°.

8. A testing method for a cross-image system according to claim 2, characterized in that: The voltage is 100KV-140KV.

9. A testing method for a cross-image system according to claim 2, characterized in that: The current is 100mA-200mA.

10. A testing method for a cross-image system according to claim 2, characterized in that: The exposure time is 0.05s-0.1s.

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