Mobile head cone beam CT (Computed Tomography) performance detection die body and use method

Abstract

The invention discloses a movable head cone beam CT (Computed Tomography) performance detection die body. Comprising an imaging uniformity module, an imaging distortion module, an image dynamic range module, an imaging consistency module, an artifact and spread function imaging module, an imaging linear module, an imaging capability module, an imaging distance module, a low-contrast test module, a high-contrast test module and an imaging adherence test module which are detachably connected. According to the invention, the test requirement that the traditional detection die body or tool is difficult to achieve the head soft tissue imaging complexity is met, the performance test can be carried out on the head soft tissue imaging of the mobile head cone beam CT, and the deficiency of detection basis or standard at home and abroad is made up.

Description

Technical Field

[0001] The present invention relates to the technical field of medical X-ray detection, and in particular to a phantom for mobile head cone beam CT performance detection and a use method thereof. Background Art

[0002] Since the emergence of cone beam tomography (CBCT) in the last century, its X-ray inspection technology has become increasingly sophisticated. CBCT is one of the standard medical equipment in hospital radiology departments and other departments, and is also one of the necessary inspection equipment for radiological examinations of patients or examinees.

[0003] CBCT is the abbreviation of Cone beam CT. As the name implies, it is a device that reconstructs cone beam radiation into tomographic images by computer. Its principle is that the X-ray tube generator performs circumferential digital radiation around the examined part with a low radiation dose, and then the surrounding imaging images are intersected and sorted. The obtained data is reorganized and fitted in the computer to obtain a three-dimensional reconstructed image, and even each thin layer of the reconstructed image can be observed, which is convenient for radiologists to make clinical judgments. The types of equipment currently used mainly include oral CBCT, breast CBCT, C-arm CBCT and medical electron accelerator CBCT.

[0004] According to statistics, about 70%-85% of the diagnosis and treatment information of patients or examinees in hospitals comes from medical X-ray images. In clinical medicine, CBCT can obtain tomographic images of patients in cross sections, sagittal planes, coronal planes and various oblique planes. It contains a large amount of information and can intuitively display the internal structure, morphology and composition of human tissues or organs. Therefore, it is widely used. However, there are many factors that affect its imaging quality, which is not only related to the type and product quality of CBCT systems produced by domestic and foreign manufacturers, but also to the imaging principle and post-processing method of the equipment itself. In order to ensure the quality of X-ray imaging of clinical patients or examinees, and thus facilitate physicians to judge the imaging results and achieve better diagnosis and treatment effects, domestic and foreign countries have always attached importance to the performance testing of this type of equipment.

[0005] It is understood that in the acute stage of stroke and brain trauma, CT scan is preferred to understand structural damage and intracranial hemorrhage. The outline of blood in the brain can be clearly seen, including extradural, subdural and brain parenchymal damage. Accurate diagnosis of acute brain trauma is particularly important for choosing appropriate treatment methods, especially when such imaging examinations can be performed at the medical scene (ambulance, intensive care unit, emergency room, etc.) or directly at the scene of brain trauma (athletes or battlefield). Ordinary CT and magnetic resonance imaging are not suitable for these occasions (they are expensive, occupy a large area, and lack mobility). Mobile head cone beam CT is one of the new radiological diagnostic equipment at home and abroad. In recent years, the newly developed mobile head cone beam CT has its unique characteristics (mobile, light weight, small volume, low maintenance cost and low radiation dose, etc.), especially the imaging quality of brain tissue has reached the clinical diagnosis level, making it a new generation of CBCT. It is planned to be mainly used in neurosurgery, spinal surgery, craniofacial surgery, otolaryngology, ICU, emergency department, etc.

[0006] Before or during the clinical application of the device, the primary guarantee is whether its imaging performance meets the standard, whether it is stable, and whether it meets the actual needs of clinical X-ray diagnosis. However, the international consensus "Quality control in cone-beam computed tomography (CBCT)" and the health industry standard WS 818-2023 "Cone-beam X-ray computed tomography (CBCT) equipment quality control test standard" do not involve the content of mobile head cone beam CT performance testing. With the frequent use of mobile head cone beam CT equipment in various places in the world (medical institutions, high-speed railways, warships, etc.), the performance testing of mobile head cone beam CT equipment has become increasingly important, but there are currently no special testing tools and methods for mobile head cone beam CT. During the test, only some indicators of mobile head cone beam CT can be tested, and the current testing tools and methods are also used, which are completely out of touch with actual needs and problems. During the normal use of mobile head cone beam CT equipment, its imaging performance quality cannot be guaranteed, and the health and safety of patients and examinees cannot be guaranteed.

[0007] Therefore, there is an urgent need for a special detection phantom for mobile head cone beam CT performance testing to ensure the normal application of the equipment. Summary of the invention

[0008] On one hand, the present invention provides a phantom for testing the performance of a mobile cone-beam CT scan of the head, which is used to solve the problem that there is currently no equipment capable of comprehensively testing the performance of a mobile cone-beam CT scan of the head. On the other hand, the present invention provides a method for using the phantom for testing the performance of a mobile cone-beam CT scan of the head.

[0009] A first aspect of the present invention provides a phantom for mobile head cone beam CT performance testing, comprising a detachably connected imaging uniformity module, an imaging distortion module, an image dynamic range module, an imaging consistency module, an artifact and spread function imaging module, an imaging linearity module, an imaging capability module, an imaging distance module, a low contrast test module, a high contrast test module and an imaging adhesion test module;

[0010] The imaging uniformity module is used to measure the uniform distribution of mobile head cone beam CT images;

[0011] The imaging distortion module is used to measure the radiation distortion error and geometric distortion error of the mobile head cone beam CT image;

[0012] The image dynamic range module is used to measure the image dynamic range and axial imaging accuracy of mobile head cone beam CT images;

[0013] The imaging consistency module is used to measure the deviation and deformation error of the imaging size of the mobile head cone beam CT image in different areas;

[0014] The artifact and spread function imaging module is used to measure mobile head cone beam CT artifacts and image spread functions caused by different metals;

[0015] The imaging linearity module is used to measure the linearity and contrast-to-noise ratio of mobile head cone beam CT imaging;

[0016] The imaging capability module is used to test the contrast imaging capability of the mobile head cone beam CT;

[0017] The imaging distance module is used to test the distance error of the mobile head cone beam CT system;

[0018] The low contrast test module is used to test the low contrast resolution of mobile head cone beam CT imaging;

[0019] The high contrast test module is used to test the spatial intermittent resolution and the spatial continuous resolution;

[0020] The imaging adhesion test module is used to test whether there are image artifacts and image regularity in the imaging.

[0021] The mobile head cone beam CT performance testing phantom, preferably, the imaging uniformity module comprises a shell, a cavity is provided inside the shell, the cavity is filled with pure water, and the shell is made of transparent plastic material.

[0022] The mobile head cone beam CT performance detection phantom, preferably, the imaging distortion module includes a plurality of square slots, the plurality of square slots are alternately arranged to form a square, the density of the materials placed in the square slots is different, and the high-density material and the low-density material are alternately arranged.

[0023] The mobile head cone beam CT performance detection phantom, preferably, the image dynamic range module includes a first substrate and a plurality of steps, the first substrate is provided with a plurality of the steps, the thickness of adjacent steps gradually increases, the material of the first substrate is organic glass, and the material of the steps is copper.

[0024] The mobile head cone beam CT performance detection phantom, preferably, the imaging consistency module includes a second substrate, a first scale mark, a second scale mark, a third scale mark and a fourth scale mark, the first scale mark, the second scale mark, the third scale mark and the fourth scale mark form four equal parts on the surface of the second substrate, each of the parts is provided with an equal number of circular modules, and the interiors of the plurality of circular modules are provided with an equal number of segmentation areas.

[0025] The mobile head cone beam CT performance detection phantom, preferably, the artifact and spread function imaging module includes a first small module, a second small module, a third small module, a fourth small module and a fifth small module;

[0026] The first small module includes two semicircular modules, the semicircular modules are assembled into a circle, and the materials of the semicircular modules are organic glass and polytetrafluoroethylene;

[0027] The second small module includes organic glass with a plurality of titanium inserts;

[0028] The third small module includes organic glass with a plurality of lead inserts inserted therein;

[0029] The fourth small module includes organic glass with a cavity in the center, and a metal wire is suspended in the center of the cavity;

[0030] The fifth small module is made of organic glass.

[0031] In the mobile head cone beam CT performance testing phantom, preferably, the imaging linear module includes a plurality of circular areas, and the material density at the center of each of the circular areas is different.

[0032] The mobile head cone beam CT performance testing phantom, preferably, the imaging capability module includes multiple areas for placing materials, the material density in each of the areas for placing materials is different, and each material in the area for placing materials has multiple sizes.

[0033] In the mobile head cone beam CT performance testing phantom, preferably, the imaging distance module includes a plurality of imaging points, and the plurality of imaging points are arranged to form a square.

[0034] The mobile head cone beam CT performance testing phantom, preferably, the low contrast test module includes a third substrate and a plug-in, the third substrate is provided with a plug-in of different materials, and the CT contrast between the material of the plug-in and the material of the third substrate is 1%.

[0035] The mobile head cone beam CT performance detection phantom, preferably, the high contrast test module includes a strip high contrast test module and a fan-shaped high contrast test module, and the imaging uniformity module, the imaging distortion module, the image dynamic range module, the imaging consistency module, the artifact and spread function imaging module, the imaging linearity module, the imaging capability module, the imaging distance module, the low contrast test module, the strip high contrast test module, the fan-shaped high contrast test module and the imaging close test module are connected in sequence.

[0036] In the mobile head cone beam CT performance testing phantom, preferably, the structure of the imaging adhesion test module includes uniformly distributed and equidistant metal grids.

[0037] A second aspect of the present invention provides a method for using a mobile head cone beam CT performance testing phantom, including the mobile head cone beam CT performance testing phantom, and the specific method of using includes the following steps:

[0038] Install a mobile head cone beam CT performance test phantom on the test vehicle;

[0039] The testing vehicle is used to adjust the mobile head cone beam CT performance testing phantom up, down, left, and right;

[0040] After the positioning is completed, the mobile head cone beam CT selects the clinical normal beam output mode to shoot and image the phantom, and then analyzes the image results of each module to determine whether the various detection indicators of the mobile head cone beam CT meet the standards;

[0041] The inspection vehicle includes a pulley, a vehicle body and an adjusting device. The pulley is provided at the bottom of the vehicle body, and the adjusting device is provided on the vehicle body. The adjusting device includes a bracket, an X-direction adjusting device, a Y-direction adjusting device and a Z-direction adjusting device. The Z-direction adjusting device is arranged on the bracket, the X-direction adjusting device is arranged on the Z-direction adjusting device, the Y-direction adjusting device is arranged on the X-direction adjusting device, and the phantom for mobile head cone beam CT performance inspection is arranged on the Y-direction adjusting device.

[0042] The method for using the mobile head cone beam CT performance detection phantom, preferably, the X-axis adjustment device includes an X-axis crank, an X-axis connecting plate, an X-axis adjustment screw, an X-axis guide rod and an X-axis connecting block, the X-axis connecting plate is fixed to the Z-axis adjustment device, one end of the X-axis adjustment screw is connected to the X-axis crank, the other end of the X-axis adjustment screw is rotatably fixed to the X-axis connecting plate, the X-axis guide rods are provided on both sides of the X-axis adjustment screw, the X-axis connecting block is fixed to the X-axis adjustment screw and sleeved on the X-axis guide rod, and the Y-axis adjustment device is fixedly provided on the X-axis connecting block.

[0043] In the method for using the mobile head cone beam CT performance detection phantom, preferably, the Y-axis adjustment device includes a limit adjustment plate, an adjustment component and a fixed plate, the limit adjustment plate is fixed to the X-axis connecting block, the fixed plate is rotatably connected to the limit adjustment plate through the adjustment component, and the limit adjustment plate covers the top of the fixed plate, and the other end of the fixed plate is connected to the mobile head cone beam CT performance detection phantom.

[0044] In the method for using the mobile head cone beam CT performance detection phantom, preferably, the adjustment component includes a rotating shaft and an adjusting bolt, the plate body of the fixed plate and the plate body of the limit adjustment plate are connected through the rotating shaft, and the end of the fixed plate and the end of the limit adjustment plate are fixed through the adjusting bolt.

[0045] The method for using the mobile head cone beam CT performance detection phantom, preferably, the Z-axis adjustment device includes a Z-axis crank, a Z-axis adjustment screw, a Z-axis guide rod and a Z-axis connecting block, one end of the Z-axis adjustment screw is connected to the Z-axis crank, the other end of the Z-axis adjustment screw is rotatably fixed to the bracket, the Z-axis guide rods are provided on both sides of the Z-axis adjustment screw, the Z-axis adjustment screw is provided with the Z-axis connecting block, and the Z-axis connecting block is sleeved on the Z-axis guide rod, and the X-axis connecting plate is fixed on the Z-axis connecting block.

[0046] The beneficial effects are:

[0047] The invention provides a complete set of mobile head cone beam CT performance test tools to protect the imaging performance quality of the device, which is helpful for clinical physicians to better judge the conditions of abnormal tissues such as brain damage, hemorrhage, tumors, etc. of patients or examinees.

[0048] Traditional detection phantoms or tools are difficult to meet the test requirements of the complexity of head soft tissue. The present invention can perform performance testing on mobile head cone beam CT for head soft tissue imaging, making up for the lack of domestic and international detection standards and methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of the structure of the mobile head cone beam CT performance test phantom;

[0050] Figure 2 It is a structural schematic diagram of the imaging uniformity module;

[0051] Figure 3 It is a structural schematic diagram of the imaging distortion module;

[0052] Figure 4 It is a structural diagram of the image dynamic range module;

[0053] Figure 5 is a structural diagram of an imaging consistency module;

[0054] Figure 6 It is a schematic diagram of the structure of the artifact and spread function imaging module;

[0055] Figure 7 It is a structural diagram of the imaging linear module;

[0056] Figure 8 is a schematic diagram of the structure of the imaging capability module;

[0057] Fig. 9 It is a structural schematic diagram of the imaging distance module;

[0058] Fig.10 It is a structural diagram of a low contrast test module;

[0059] Figure 11-1 It is a structural schematic diagram of the sector resolution module;

[0060] Figure 11-2 It is a bar resolution test module;

[0061] Fig.12 It is a structural schematic diagram of an imaging adhesion test module;

[0062] Fig.13 A three-dimensional image of the inspection vehicle;

[0063] Fig.14 This is the rear view of the test vehicle.

[0064] In the figure,

[0065] 1. X-axis crank handle; 2. X-axis connecting plate; 3. X-axis adjusting screw rod; 4. X-axis guide rod;

[0066] 5. X-axis connecting block; 6. Limit adjustment plate; 7. Mobile head cone beam CT performance detection phantom; 8. Fixed plate; 9. Rotating shaft; 10. Adjustment bolt; 11. Z-axis crank; 12. Z-axis adjustment screw rod; 13. Z-axis guide rod; 14. Z-axis connecting block; 15. Bracket; 16. Car body; 17. Pulley; 18. Connection hole; 19. Shell; 20. Cavity; 21. Water inlet;

[0067] 22. A square tank for placing low-density materials; 23. A square tank for placing high-density materials;

[0068] 24. first substrate; 25. step; 26. second substrate; 27. first scale mark;

[0069] 28, second scale mark; 29, third scale mark; 30, fourth scale mark;

[0070] 31. circular module; 32. first small module; 33. second small module; 34. third small module; 35. fourth small module; 36. circular area; 37. area for placing materials; 38. imaging point; 39. plug-in; 40. third substrate; 41. connecting rod;

[0071] 42. Metal grid; 43. Compensation rod; 44. Imaging uniformity module;

[0072] 45. Imaging distortion module; 46. Image dynamic range module; 47. Imaging consistency module; 48. Artifact and spread function imaging module; 49. Imaging linearity module; 50. Imaging capability module;

[0073] 51. Imaging distance module; 52. Low contrast test module; 53. Bar high contrast test module;

[0074] 54. Fan-shaped high contrast test module; 55. Imaging adhesion test module; 56. Fixed plate;

[0075] 57. The fifth small module. DETAILED DESCRIPTION

[0076] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0077] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner" and "outer" indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the system or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used to define components only for the convenience of distinguishing the above components. If not otherwise stated, the above terms have no special meanings and cannot be understood as indicating or implying relative importance.

[0078] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0079] The present invention provides a phantom for performance testing of a mobile cone beam CT of the head, comprising a detachably connected imaging uniformity module, an imaging distortion module, an image dynamic range module, an imaging consistency module, an artifact and spread function imaging module, an imaging linearity module, an imaging capability module, an imaging distance module, a low contrast test module, a high contrast test module and an imaging adhesion test module; the imaging uniformity module is used to measure the uniform distribution of a mobile cone beam CT image of the head; the imaging distortion module is used to measure the radiation distortion error and the geometric distortion error of the mobile cone beam CT image of the head; the image dynamic range module is used to measure the image dynamic range and the accuracy of axial imaging of the mobile cone beam CT image of the head; the imaging consistency module is used to measure the uniform distribution of a mobile cone beam CT image of the head; the imaging uniformity ... Deviations and deformation errors of the imaging size of mobile head cone beam CT images in different areas; the artifact and spread function imaging module is used to measure the mobile head cone beam CT artifacts and spread functions caused by different metals; the imaging linearity module is used to measure the linearity and contrast-to-noise ratio of mobile head cone beam CT imaging; the imaging capability module is used to test the contrast imaging capability of mobile head cone beam CT; the imaging distance module is used to test the distance error of the mobile head cone beam CT system; the low contrast test module is used to test the low contrast resolution of mobile head cone beam CT imaging; the high contrast test module is used to test the spatial intermittent resolution and spatial continuous resolution; the imaging close test module is used to test whether there are image artifacts in the imaging. The traditional detection phantom or tool of the present invention is difficult to meet the test requirements of the complexity of the soft tissue of the head. The present invention can image the soft tissue of the head, making up for the lack of domestic and foreign detection standards.

[0080] The entire technical process is described in detail below using a mobile head cone beam CT performance testing phantom as an example.

[0081] Example 1

[0082] like Figure 1-Figure 10 , Figure 11-1 , Figure 11-2 and Fig.12 The phantom shown is for mobile head cone beam CT performance testing, comprising a detachably connected imaging uniformity module 44, an imaging distortion module 45, an image dynamic range module 46, an imaging consistency module 47, an artifact and spread function imaging module 48, an imaging linearity module 49, an imaging capability module 50, an imaging distance module 51, a low contrast test module 52, a high contrast test module and an imaging adhesion test module 55.

[0083] Among them, a mobile head cone beam CT performance detection phantom 7 also includes a fixed plate 56. Preferably, an imaging uniformity module 44, an imaging distortion module 45, an image dynamic range module 46, an imaging consistency module 47, an artifact and spread function imaging module 48, an imaging linearity module 49, an imaging capability module 50, an imaging distance module 51, a low contrast test module 52, a high contrast test module, an imaging adhesion test module 55 and a fixed plate 56 are arranged and connected in sequence.

[0084] Among them, the imaging uniformity module 44, the imaging distortion module 45, the image dynamic range module 46, the imaging consistency module 47, the artifact and spread function imaging module 48, the imaging linearity module 49, the imaging capability module 50, the imaging distance module 51, the low contrast test module 52, the high contrast test module and the imaging adhesion test module 55 are surrounded by connecting holes 18, and the connecting holes 18 are provided with connecting rods 41 to achieve the function of fixing each module;

[0085] The connecting rod 41 is a long rod type dose detector, which can fix each module on the one hand, and replace the dose detector on the other hand, and also has the function of measuring the dose; the number of connecting rods 41 can be 4 as shown in the figure, and the number of connecting rods 41 can also be 3, which can measure the dose at 0 o'clock, 3 o'clock, 6 o'clock and 9 o'clock.

[0086] A compensation rod 43 is provided at the center of the imaging uniformity module 44, the imaging distortion module 45, the image dynamic range module 46, the imaging consistency module 47, the artifact and spread function imaging module 48, the imaging linearity module 49, the imaging capability module 50, the imaging distance module 51, the low contrast test module 52, the high contrast test module and the imaging adhesion test module 55.

[0087] like Figure 2As shown, the imaging uniformity module 44 includes a shell 19, a cavity 20 is provided inside the shell 19, the cavity 20 is in a round shape, the shell 19 is made of transparent plastic, a water inlet 21 is provided on the shell 19, the water inlet 21 is connected to the cavity 20, and the cavity 20 is filled with pure water.

[0088] The imaging uniformity module 44 is used to measure the uniform distribution of the mobile head cone beam CT image. A uniform distribution indicates that the imaging quality of the device is good.

[0089] like Figure 3 As shown, the imaging distortion module 45 includes a plurality of square slots, which are alternately arranged to form a square, and the density of the materials placed in the square slots is different, and the square slots 23 for placing high-density materials and the square slots 22 for placing low-density materials are alternately arranged. Among them, the materials in the square slots 23 for placing high-density materials are all the same, and the materials in the square slots 22 for placing low-density materials are all the same.

[0090] The imaging distortion module 45 is used to measure the radiation distortion error and geometric distortion error of the mobile head cone beam CT image to indicate whether there is deformation or image distortion between the imaging result and the actual situation.

[0091] like Figure 4 As shown, the image dynamic range module 46 includes a first substrate 24 and a plurality of steps 25 . The first substrate 24 is provided with a plurality of steps 25 , and the thickness of adjacent steps 25 gradually increases. The material of the first substrate 24 is organic glass, and the material of the steps 25 is copper.

[0092] The image dynamic range module 46 is used to measure the image dynamic range and axial imaging accuracy of the mobile head cone beam CT image, which indicates the imaging resolution and imaging capability of tissues of different thicknesses.

[0093] like Figure 5 As shown, the imaging consistency module 47 includes a second substrate 26, a first scale mark 27, a second scale mark 28, a third scale mark 29 and a fourth scale mark 30. The first scale mark 27, the second scale mark 28, the third scale mark 29 and the fourth scale mark 30 form four equal parts on the surface of the second substrate 26, and each of the parts is provided with an equal number of circular modules 31, and the interiors of the plurality of circular modules 30 are provided with an equal number of partition areas.

[0094] The imaging consistency module 47 is used to measure the deviation of the imaging size and the deformation error of the mobile head cone beam CT image in different areas, indicating that the imaging results of each involved area are consistent within the entire field of view.

[0095] like Figure 6As shown, the artifact and spread function imaging module 48 includes a first small module 32, a second small module 33, a third small module 34, a fourth small module 35 and a fifth small module 57;

[0096] The first small module 32 includes two semicircular modules, the semicircular modules are assembled into a circle, the materials of the semicircular modules are organic glass and polytetrafluoroethylene, half of the semicircular module is high-density polytetrafluoroethylene, and the other half is organic glass, and the boundary line is used to test the imaging line spread function;

[0097] The second small module 33 includes organic glass with a plurality of titanium inserts inserted therein, and the third small module 34 includes organic glass with a plurality of lead inserts inserted therein; the second small module 33 and the third small module 34 are artifact modules for imaging artifacts;

[0098] The fourth small module 35 includes organic glass with a cavity in the center, and a metal wire is suspended in the center of the cavity; that is, the metal wire is located in the center of the entire cavity, suspended in the air, and fixed at both ends, for testing the point spread function;

[0099] The fifth small module 57 is made of organic glass.

[0100] like Figure 7 As shown, the imaging linear module 49 includes a plurality of circular regions 36 , and the material density at the center of each circular region 36 is different.

[0101] The imaging linearity module 49 is used to measure the linearity and contrast-to-noise ratio of mobile head cone beam CT imaging, indicating the difference between the imaging capability of different human tissue densities and the actual size.

[0102] like Figure 8 As shown, the imaging capability module 50 includes a plurality of areas 37 for placing materials, the material density in each area 37 for placing materials is different, and each material in the area 37 for placing materials has a plurality of sizes.

[0103] The imaging capability module 50 is used to test the contrast imaging capability of the mobile head cone beam CT.

[0104] like Fig. 9 As shown, the imaging distance module 51 includes a plurality of imaging points 38, and the plurality of imaging points 38 are arranged to form a square. Preferably, the size of the imaging point 38 is 2 mm, the center distance between adjacent imaging points 38 is 10 mm, and the imaging points 38 are composed of 80 points in total.

[0105] The imaging distance module 51 is used to test the distance error of the mobile head cone beam CT system, which indicates the deviation between the imaging size and the actual size.

[0106] like Fig.10As shown, the low contrast test module 52 includes a third substrate 40 and a plug-in 39. A plug-in 39 made of different materials is arranged on the third substrate 40. The CT contrast between the material of the plug-in 39 and the material of the third substrate 40 is 1%. The sizes of the plug-ins 39 are arranged in a circle from large to small, and the size of the plug-in 39 is 2-15 mm.

[0107] The low contrast test module 52 is used to test the low contrast resolution of the mobile head cone beam CT imaging, which indicates the low-density tissue imaging capability of the device.

[0108] like Figure 11-1 and Figure 11-2 As shown, the high contrast test module includes a bar-shaped high contrast test module 53 and a fan-shaped high contrast test module 54 .

[0109] An imaging uniformity module 44, an imaging distortion module 45, an image dynamic range module 46, an imaging consistency module 47, an artifact and spread function imaging module 48, an imaging linearity module 49, an imaging capability module 50, an imaging distance module 51, a low contrast test module 52, a strip high contrast test module 53, a fan-shaped high contrast test module 54 and an imaging adhesion test module 55 are connected in sequence.

[0110] The two high contrast test modules use space discontinuity (such as Figure 11-2 ) resolution test and spatial continuity (such as Figure 11-1 ) resolution test, which indicates the ability to distinguish the minimum size of the image, indicating that the device has strong imaging capabilities. The high contrast test module is used to test spatial intermittent resolution and spatial continuous resolution.

[0111] like Fig.12 As shown, the imaging adhesion test module 55 includes metal grids 42 that are evenly distributed and equally spaced.

[0112] The imaging adhesion test module 55 is used to test whether there are image artifacts and image regularity in the imaging.

[0113] Example 2

[0114] like Fig.13 and Fig.14 A method for using a mobile head cone beam CT performance testing phantom is shown, characterized in that it includes the mobile head cone beam CT performance testing phantom 7 described in Example 1. The specific method of using includes the following steps:

[0115] Step S1: installing a mobile head cone beam CT performance testing phantom 7 on a testing vehicle;

[0116] Step S2: the inspection vehicle is capable of adjusting the upper, lower, left and right devices of the mobile head cone beam CT performance inspection phantom 7;

[0117] The inspection vehicle includes a pulley 17, a vehicle body 16 and an adjusting device. The pulley 17 is provided at the bottom of the vehicle body 16, and the adjusting device is provided on the vehicle body 16. The adjusting device includes a bracket 15, an X-direction adjusting device, a Y-direction adjusting device and a Z-direction adjusting device. The Z-direction adjusting device is arranged on the bracket 15, the X-direction adjusting device is arranged on the Z-direction adjusting device, the Y-direction adjusting device is arranged on the X-direction adjusting device, and the phantom 7 for mobile head cone beam CT performance inspection is arranged on the Y-direction adjusting device.

[0118] The X-direction adjustment device includes an X-direction crank 1, an X-direction connecting plate 2, an X-direction adjustment screw 3, an X-direction guide rod 4 and an X-direction connecting block 5. The X-direction connecting plate 2 is fixed to the Z-direction adjustment device, one end of the X-direction adjustment screw 3 is connected to the X-direction crank 1, and the other end of the X-direction adjustment screw 3 is rotatably fixed to the X-direction connecting plate 2. X-direction guide rods 4 are provided on both sides of the X-direction adjustment screw 3. The X-direction connecting block 5 is fixed on the X-direction adjustment screw 3 and sleeved on the X-direction guide rod 4. The Y-direction adjustment device is fixed on the X-direction connecting block 5.

[0119] The Y-axis adjustment device includes a limit adjustment plate 6, an adjustment component and a fixed plate 8. The limit adjustment plate 6 is fixed to the X-axis connecting block 5. The fixed plate 8 is rotatably connected to the limit adjustment plate 6 through the adjustment component. In addition, the limit adjustment plate 6 covers the top of the fixed plate 8. The other end of the fixed plate 8 is connected to a mobile head cone beam CT performance detection phantom 7.

[0120] The adjustment assembly includes a rotating shaft 9 and an adjusting bolt 10 . The plate body of the fixed plate 8 is connected to the plate body of the limit adjustment plate 6 via the rotating shaft 9 . The end of the fixed plate 8 is fixed to the end of the limit adjustment plate 6 via the adjusting bolt 10 .

[0121] The Z-axis adjustment device includes a Z-axis crank 11, a Z-axis adjustment screw 12, a Z-axis guide rod 13 and a Z-axis connecting block 14. One end of the Z-axis adjustment screw 12 is connected to the Z-axis crank 11, and the other end of the Z-axis adjustment screw 12 is rotatably fixed on the bracket 15. Z-axis guide rods 13 are provided on both sides of the Z-axis adjustment screw 12. A Z-axis connecting block 14 is provided on the Z-axis adjustment screw 12, and the Z-axis connecting block 14 is sleeved on the Z-axis guide rod 13. The X-axis connecting plate 2 is fixed on the Z-axis connecting block 14.

[0122] Step S3: After the positioning is completed, the mobile head cone beam CT selects the clinical normal beam output mode to shoot and image the phantom, and then analyzes the image results of each module to determine whether the various detection indicators of the mobile head cone beam CT meet the standards.

[0123] The working process of the device of the inspection vehicle capable of adjusting the upper, lower, left and right positions of the mobile head cone beam CT performance inspection phantom 7 is as follows:

[0124] When the upper and lower positions of the mobile head cone-beam CT performance detection phantom 7 need to be adjusted, the Z-direction crank 11 is manually cranked to adjust the position of the Z-direction connection block 14, thereby adjusting the upper and lower positions of the mobile head cone-beam CT performance detection phantom 7;

[0125] When the left-right position of the mobile head cone-beam CT performance detection phantom 7 needs to be adjusted, the X-direction crank 1 is manually cranked to adjust the position of the X-direction guide rod 4, thereby adjusting the left-right position of the mobile head cone-beam CT performance detection phantom 7;

[0126] When the pitch position of the mobile head cone-beam CT performance detection phantom 7 needs to be adjusted, the fixing plate 8 is released by tightening the adjusting bolt 10, and the pitch position of the mobile head cone-beam CT performance detection phantom 7 is adjusted by rotating the fixing plate 8 around the rotating shaft 9.

[0127] After positioning is completed, the mobile head cone beam CT selects the clinical normal beam output mode to capture and image the phantom, and then analyzes the image results of each module to determine whether the various detection indicators of the device meet the standards.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A phantom for mobile head cone beam CT performance testing, characterized in that: It includes a detachably connected imaging uniformity module, an imaging distortion module, an imaging dynamic range module, an imaging consistency module, an artifact and spread function imaging module, an imaging linearity module, an imaging capability module, an imaging distance module, a low contrast test module, a high contrast test module and an imaging adhesion test module; The imaging uniformity module is used to measure the uniform distribution of mobile head cone beam CT images; The imaging distortion module is used to measure the radiation distortion error and geometric distortion error of the mobile head cone beam CT image; The image dynamic range module is used to measure the image dynamic range and axial imaging accuracy of mobile head cone beam CT images; The imaging consistency module is used to measure the deviation and deformation error of the imaging size of the mobile head cone beam CT image in different areas; The artifact and spread function imaging module is used to measure the mobile head cone beam CT artifacts and image spread functions caused by different metals; The imaging linearity module is used to measure the linearity and contrast-to-noise ratio of mobile head cone-beam CT imaging; The imaging capability module is used to test the contrast imaging capability of the mobile head cone beam CT; The imaging distance module is used to test the distance error of the mobile head cone beam CT system; The low contrast test module is used to test the low contrast resolution of mobile head cone beam CT imaging; The high contrast test module is used to test the spatial intermittent resolution and the spatial continuous resolution; The imaging adhesion test module is used to test whether there are image artifacts and image regularity in the imaging.

2. The mobile head cone beam CT performance testing phantom according to claim 1, characterized in that: The imaging consistency module includes a second substrate, a first scale mark, a second scale mark, a third scale mark and a fourth scale mark, wherein the first scale mark, the second scale mark, the third scale mark and the fourth scale mark form four equal parts on the surface of the second substrate, each of the parts is provided with an equal number of circular modules, and an equal number of segmentation areas are provided inside the plurality of circular modules.

3. The mobile head cone beam CT performance testing phantom according to claim 1, characterized in that: The artifact and spread function imaging module includes a first small module, a second small module, a third small module, a fourth small module and a fifth small module; The first small module includes two semicircular modules, the semicircular modules are assembled into a circle, and the materials of the semicircular modules are organic glass and polytetrafluoroethylene; The second small module includes organic glass with a plurality of titanium inserts; The third small module includes organic glass with a plurality of lead inserts inserted therein; The fourth small module includes organic glass with a cavity in the center, and a metal wire is suspended in the center of the cavity; The fifth small module is made of organic glass.

4. The mobile head cone beam CT performance testing phantom according to claim 1, characterized in that: The imaging linear module includes a plurality of circular areas, and the material density at the center of each of the circular areas is different.

5. The mobile head cone beam CT performance testing phantom according to claim 1, characterized in that: The imaging capability module includes a plurality of areas for placing materials, the material density in each of the areas for placing materials is different, and each material in the areas for placing materials has a plurality of sizes.

6. The mobile head cone beam CT performance testing phantom according to claim 1, characterized in that: The imaging distance module includes a plurality of imaging points, and the plurality of imaging points are arranged to form a square.

7. The mobile head cone beam CT performance testing phantom according to claim 1, characterized in that: The low contrast test module comprises a third substrate and an inserter, wherein the inserter made of a different material is arranged on the third substrate, and the CT contrast between the material of the inserter and the material of the third substrate is 1%.

8. The mobile head cone beam CT performance testing phantom according to claim 1, characterized in that: The high contrast test module includes a strip high contrast test module and a sector high contrast test module, and the imaging uniformity module, the imaging distortion module, the image dynamic range module, the imaging consistency module, the artifact and spread function imaging module, the imaging linearity module, the imaging capability module, the imaging distance module, the low contrast test module, the strip high contrast test module, the sector high contrast test module and the imaging adhesion test module are connected in sequence.

9. The mobile head cone beam CT performance testing phantom according to claim 1, characterized in that: The structure of the imaging adhesion test module includes metal grids that are evenly distributed and equidistant.

10. A method for using a mobile head cone beam CT performance testing phantom, characterized in that: The method comprises the mobile head cone beam CT performance testing phantom according to any one of claims 1 to 9, and the specific method of using the phantom comprises the following steps: Install a mobile head cone beam CT performance test phantom on the test vehicle; The testing vehicle is used to adjust the mobile head cone beam CT performance testing phantom up, down, left, and right; After the positioning is completed, the mobile head cone beam CT selects the clinical normal beam output mode to shoot and image the phantom, and then analyzes the image results of each module to determine whether the various detection indicators of the mobile head cone beam CT meet the standards; The inspection vehicle includes a pulley, a vehicle body and an adjusting device. The pulley is provided at the bottom of the vehicle body, and the adjusting device is provided on the vehicle body. The adjusting device includes a bracket, an X-direction adjusting device, a Y-direction adjusting device and a Z-direction adjusting device. The Z-direction adjusting device is arranged on the bracket, the X-direction adjusting device is arranged on the Z-direction adjusting device, the Y-direction adjusting device is arranged on the X-direction adjusting device, and the phantom for mobile head cone beam CT performance inspection is arranged on the Y-direction adjusting device.

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