Model body for quality control detection of CT (Computed Tomography) simulator

Abstract

The invention provides a motif for quality control detection of a CT simulator, and relates to the field of motifs. The die body comprises a die body base and a die body main body; the die body base is provided with a leveling structure, leveling display structures are arranged on the periphery of the die body base, and horizontal scales are arranged on the front side and the rear side of the die body base respectively. Supporting structures are fixed to the two ends of the die body base respectively. The die body is erected between the two supporting structures, the two ends of the die body are rotationally connected with the two supporting structures correspondingly, and vertical scales are arranged on the outer sides, away from the die body, of the two supporting structures correspondingly; the mold body comprises a first module, a second module, a third module and a fifth module which are sequentially stacked. The first module is a mechanical performance detection module; the second module is a spatial resolution and high resolution detection module; the third module is a low-contrast resolution detection module and a high-contrast resolution detection module; the fourth module is an electron density module; the fifth module is a hollow water injection module. The detection link operation process is simplified, and the detection efficiency is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of phantoms, in particular to a phantom for CT simulator quality control detection. BACKGROUND

[0002] Radiotherapy is one of the three major means of tumor treatment and is an important non-invasive treatment method. In the whole process of radiotherapy, simulation positioning is the first link, which provides the image and body position reference for the subsequent scheme formulation and treatment, so the accuracy of the simulation positioning link is particularly important. The principle of a CT simulator is the same as that of a diagnostic CT machine, that is, X-ray imaging is used. Unlike the diagnostic CT machine, the CT simulator needs to provide high-precision positioning images in addition to high-quality images for radiotherapy. The CT simulator is composed of a gantry system, a positioning bed system and a laser lamp system as a whole, and each subsystem and the whole has corresponding precision requirements. In 2021, the National Cancer Center issued the "CT Simulator Quality Control Guide", which clearly stipulates the quality control items and frequency. Since there are many detection items, currently, multiple tools and phantoms are needed for quality control work, which requires multiple positioning and scanning to complete, making the detection work tedious and time-consuming, and some detection items cannot be quantitatively measured.

[0003] Therefore, the application provides a phantom for CT simulator quality control detection to solve the above technical problems. SUMMARY

[0004] The application provides a quality control detection phantom, which can complete daily quality control detection items such as laser system, positioning bed system, mechanical performance of gantry and image quality detection according to the NCC / T-RT 006-2021 "CT Simulator Quality Control Guide", so as to solve the problems of multiple detection links, single detection function, multiple positioning and inability to quantitatively measure some detection items, simplify the operation process and improve the detection efficiency.

[0005] Based on the above purpose, the application provides a phantom for CT simulator quality control detection, which comprises a phantom base and a phantom body.

[0006] The phantom base is provided with a leveling structure, the phantom base is provided with leveling display structures around, and the front and rear sides of the phantom base are respectively provided with horizontal direction scales.

[0007] Both ends of the phantom base are respectively fixed with support structures, the phantom body is arranged between the two support structures, both ends of the phantom body are respectively rotationally connected with the two support structures, and angle locking structures are respectively arranged between the two support structures and the phantom body.

[0008] Two of the support structures are respectively provided with vertical direction scales away from the outside of the phantom body.

[0009] The phantom body comprises module one, module two, module three, module four and module five which are stacked in sequence.

[0010] The module one is a mechanical performance detection module; the module two is a spatial resolution and high resolution detection module; the module three is a low contrast resolution and high contrast resolution detection module; the module four is an electron density module; and the module five is a hollow water injection module.

[0011] Optionally, each module is disc-shaped, and the main body of each module is made of polyethylene.

[0012] Optionally, the module one is embedded with five groups of metal cross lines, one of which is located at the center of the module one, and the other four are uniformly distributed around the center of the module one.

[0013] Optionally, the module two is integrated with a spatial integrity, layer thickness detection device, and a CT value linearity detection device.

[0014] Optionally, the module three is integrated with a low contrast resolution and high contrast resolution detection device.

[0015] Optionally, the module four is internally provided with a plurality of phantom inserts with different electron densities.

[0016] Optionally, the plurality of density phantom inserts at least include density phantom inserts of an inhaled lung, an exhaled lung, fat, breast, muscle, liver and four different density bone tissues.

[0017] Optionally, the module five is hollow inside and is provided with a sealable water injection hole at the top of the module.

[0018] Optionally, the peripheral side of each module is respectively provided with four groups of cross mark lines, and the four groups of cross mark lines are uniformly distributed around the center of the corresponding module.

[0019] Optionally, the outer surfaces of the two support structures are respectively provided with cross mark lines corresponding to the center of the phantom body.

[0020] Compared with the existing CT simulator quality control phantom, the phantom for CT simulator quality control detection provided in the application can complete CT simulator related mechanical performance detection through fewer positioning times by using one phantom, and can complete image quality detection through integrated image quality detection modules, thereby reducing the complexity and repeatability of positioning and simplifying the operation process. The phantom can quantify the error of a laser lamp and simultaneously solve the problem of insufficient positioning level of the existing CT simulator detection phantom. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the drawings needed to be used in the description of the specific embodiments or prior art will be briefly introduced as follows. The drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0022] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. It will be appreciated that the drawings described are for purposes of illustration only and are not intended to limit the present application thereto. Moreover, the same reference numerals in the entire drawings denote the same elements. In the drawings:

[0023] Figure 1 A front view of a phantom for CT simulator quality control detection provided by an embodiment of the present application;

[0024] Figure 2 A top view of a phantom for CT simulator quality control detection shown in Figure 1

[0025] Figure 3 A left view of a phantom for CT simulator quality control detection shown in Figure 1

[0026] Figure 4 A right view of a phantom for CT simulator quality control detection shown in Figure 1

[0027] Figure 5 A module 1 view of a phantom for CT simulator quality control detection provided by an embodiment of the present application;

[0028] Figure 6 A module 2 view of a phantom for CT simulator quality control detection provided by an embodiment of the present application.

[0029] ​​​Icon: 1-Module body, 11-Module 1, 12-Module 2, 13-Module 3, 14-Module 4, 15-Module 5, 111-Module side cross line, 2-Module base, 21-Balance nut, 22-Level bubble, 23-Base scale line, 31-Left side stand, 311-Left side rotating shaft, 32-Right side stand, 321-Right side rotating shaft, 312-Left side stand top metal ball, 322-Right side stand top metal ball, 112-Module top cross line, 151-Water injection hole, 313-Tightening nut, 314-Key groove, 315-Left side stand scale line, 316-Left side stand cross line, 323-Right side stand cross line, 324-Right side stand scale line, 325-Pointer, 326-Rotation scale, 113-Module 1 inner metal cross line, 141-Module 4 inner plug. DETAILED DESCRIPTION

[0030] Example embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings. While example embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0031] It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "includes", "including" and "has" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order in which they are described, unless specifically identified as an order dependent step. It is also to be understood that additional or alternative steps can be employed.

[0032] Although the terms first, second, third, and the like can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can be only used to distinguish one element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second", and the like are used herein to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of example embodiments.

[0033] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0034] Example 1

[0035] like Figures 1-6 As shown, this embodiment provides a phantom for quality control testing of a CT simulator, the phantom for quality control testing of a CT simulator including a phantom base and a phantom body;

[0036] The mold base is equipped with a leveling structure, preferably in the form of four horizontal adjustment nuts at the four corners of the base. A leveling display structure is provided around the mold base, preferably a cylindrical spirit level. Horizontal graduations are provided on the front and rear sides of the mold base.

[0037] The two ends of the mold base are respectively fixed with support structures, preferably columns.

[0038] The mold body is mounted between the two columns, and both ends of the mold body are rotatably connected to the two columns respectively. Preferably, both ends of the mold body have protruding rotating shafts that extend beyond the mold body and are connected to the columns through the rotating shafts. The mold body can rotate ±5° (clockwise and counterclockwise) through the rotating shafts. Furthermore, there is a pointer at the end of one side shaft and a ±5° rotation scale on the outer surface of the side column.

[0039] Angle locking structures are respectively provided between the two columns and the mold body. Preferably, there is a horizontal protruding keyway at the end of the other side shaft. Furthermore, there is a nut that can be tightened at the top and bottom of the keyway.

[0040] Vertical graduations are provided on the outer sides of the two pillars; furthermore, a metal ball with a diameter of 1mm is embedded in the center of the top of each pillar.

[0041] The phantom body comprises module one, module two, module three, module four and module five which are stacked in sequence.

[0042] The module one is a mechanical performance detection module; the module two is a spatial resolution and high resolution detection module; the module three is a low contrast resolution and high contrast resolution detection module; the module four is an electron density module; and the module five is a hollow water injection module. Each module is in a cylindrical shape with a diameter of 20 cm and a thickness of 5 cm. Each module is made of polyethylene except that the inside is embedded with an insert.

[0043] As Figures 1-6 shown in the optional solution of the embodiment, five groups of metal cross lines are embedded in the module one, one group of which is located at the center of the module one and the other four groups of which are uniformly distributed around the center of the module one.

[0044] Further, the module two is integrated with a spatial integrity, layer thickness detection device and a CT value linearity detection device.

[0045] Further, the module three is integrated with a low contrast resolution and high contrast resolution detection device.

[0046] Further, the module four is internally provided with a plurality of phantom inserts with different electron densities.

[0047] Further, the plurality of phantom inserts are divided into an inner circle and an outer circle, and the inner circle and the outer circle are uniformly distributed.

[0048] Further, the plurality of phantom inserts at least include density phantom inserts of an inhaled lung, an exhaled lung, fat, breast, muscle, liver and four different density bone tissues.

[0049] Further, the module five is hollow inside and is provided with a sealable water injection hole at the top of the module.

[0050] Further, each module is provided with four groups of cross mark lines on the circumferential side, and the four groups of cross mark lines are uniformly distributed around the center of the corresponding module.

[0051] Further, the outer surfaces of the two support structures are provided with cross mark lines corresponding to the center of the phantom body.

[0052] Embodiment two

[0053] As Figures 1-6 shown, the laser lamp detection implementation scene is as follows:

[0054] Place the phantom on the CT bed, and position the phantom according to the laser system of the gantry or the external laser system. Place the phantom on the CT bed, and adjust the phantom so that the laser lights in the sagittal and transverse directions coincide with the cross lines 111 and 112 on the surface of the module 1 11. Adjust the four balance nuts 21 of the base of the phantom so that the bubbles in the level bubbles 22 around the base are in the center position. Rotate the phantom slightly by rotating the shafts 311 and 321, and adjust the height of the bed so that the horizontal laser lights (in the coronal direction) coincide with the horizontal cross lines 111 on both sides of the module 1. Use the screw nuts 313 to fix the key grooves 314 so that the phantom body is fixed. At this time, the coincidence of the laser lights in the sagittal and horizontal directions at the distal end of the phantom with the mark lines on the surface of the phantom can be observed.

[0055] Axial scanning is performed with the minimum layer thickness and layer spacing.

[0056] The five groups of cross mark lines 113 in the module 1 11 are evaluated. First, the height difference of the horizontal lines of the cross mark lines on both sides at the center is measured to determine the coplanarity of the horizontal laser lights. Whether the cross mark lines on both sides appear simultaneously in the first layer image is observed to determine the coplanarity of the laser lights in the transverse direction. According to the appearance of the cross lines in the sagittal, coronal and transverse directions, the corresponding relationship with the scanning plane is measured and calculated.

[0057] The coincidence of the cross mark lines 113 with the center of the image is observed by using the grid mark line tool of the scanning image to determine the coincidence of the laser indicating center with the scanning center point.

[0058] The verticality of the sagittal laser light with the scanning plane is determined by the coincidence of the vertical cross lines 316 and 323 on the columns of the base of the phantom with the sagittal laser light, or the coincidence of the sagittal cross line 112 on the surface of the phantom with the sagittal laser light.

[0059] The movement accuracy of the laser light in each direction is checked in turn by using the scale lines 23, 315 and 324 around the base of the phantom and on the columns.

[0060] The surface cross lines of the module 1 are aligned with the laser light in the gantry, the bed is withdrawn to the external laser positioning layer, and whether the external laser light is aligned with each of the cross lines on the surface of the module 1 is observed to determine the verticality of the sagittal and coronal laser lights with the scanning plane.

[0061] Example Three

[0062] Positioning bed detection implementation scenario:

[0063] Place the phantom on the CT positioning bed, and position the phantom according to the laser light system. Place the phantom on the CT positioning bed, and adjust the phantom so that the laser lights in the sagittal and transverse directions coincide with the cross lines 111 and 112 on the surface of the module one 11. Adjust the four balancing nuts 21 of the phantom base so that the bubbles in the level bubbles 22 around the phantom base are in the center position. Gently rotate the phantom by rotating the shafts 311 and 321, and adjust the height of the bed so that the horizontal laser lights (in the coronal direction) coincide with the horizontal cross lines 111 on both sides of the module one. Use the tightening nut 313 to fix the key groove 314 so that the phantom body is fixed.

[0064] After positioning, use the scale line 23 of the phantom base and the scale lines 315 and 324 of the side columns to move the CT positioning bed in and out and up and down, compare the readings of the CT simulation machine coordinate indication panel with the scale values of the phantom base and the side columns, and calculate the movement accuracy of the CT positioning bed.

[0065] Move the CT bed in the in-out direction, and finely adjust the position of the phantom so that the metal ball 312 at the top of the side column 31 and the metal ball 322 at the top of the side column 32 are both located at the intersection of the laser lights.

[0066] Scan the phantom, and calculate the vertical deviation of the bed from the scanning plane during the in-out movement by measuring the position coordinates of the two metal balls and the distance between the two metal balls.

[0067] Example Four

[0068] Image quality detection scenario

[0069] Fill the module five 15 with pure water through the water injection hole 151.

[0070] Place the phantom on the CT positioning bed, and position the phantom according to the laser light system. Place the phantom on the CT positioning bed, and adjust the phantom so that the laser lights in the sagittal and transverse directions coincide with the cross lines 111 and 112 on the surface of the module one 11. Adjust the four balancing nuts 21 of the phantom base so that the bubbles in the level bubbles 22 around the phantom base are in the center position. Gently rotate the phantom by rotating the shafts 311 and 321, and adjust the height of the bed so that the horizontal laser lights (in the coronal direction) coincide with the horizontal cross lines 111 on both sides of the module one. Use the tightening nut 313 to fix the key groove 314 so that the phantom body is fixed.

[0071] Perform thin layer scanning of the entire phantom at a voltage of 120 kV and a current of 300 mAs.

[0072] Analyze and measure the module two 12 to obtain the spatial integrity, layer thickness, and CT value linearity results.

[0073] The analysis and measurement module three 13 obtains low resolution and high contrast resolution results.

[0074] The analysis and measurement module four 14 obtains CT-electronic density curves.

[0075] The analysis and measurement module five 15 obtains CT value accuracy, image noise and uniformity results.

[0076] It should finally be stated that, for the person skilled in the art, it is apparent that the present application is not limited to the details of the above-described exemplary embodiments, but can be implemented in other concrete forms without departing from the spirit or the basic characteristics of the present application. Therefore, the embodiments should be considered as exemplary and non-limiting, the scope of the present application being defined by the claims appended hereto and not by the above description, and all the variations falling within the meaning and the scope of the equivalent elements of the claims are intended to be encompassed by the present application.

[0077] Furthermore, it should be understood that, although the present description is made according to embodiments, not every embodiment contains only one independent technical solution, and the present description is described in this way only for the sake of clarity, the person skilled in the art should consider the present description as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that the person skilled in the art can understand.

Claims

1. A phantom for CT simulator quality control testing, characterized by, The phantom base and the phantom body are included; The phantom base is provided with a leveling structure, and the phantom base is provided with leveling display structures around the phantom base. The two ends of the phantom base are respectively fixed with support structures, and the phantom body is arranged between the two support structures and is rotatably connected to the two support structures. The outer sides of the two support structures away from the phantom body are respectively provided with vertical direction scales. The phantom body includes module one, module two, module three, module four and module five which are sequentially stacked. The module one is a mechanical performance detection module, the module two is a spatial resolution and high resolution detection module, the module three is a low contrast resolution and high contrast resolution detection module, the module four is an electron density module, and the module five is a hollow water injection module.

2. Phantom for CT simulator quality control detection according to claim 1, characterized in that, Each module is in the shape of a disc, and the main body of each module is made of polyethylene.

3. Phantom for CT simulator quality control detection according to claim 2, characterized in that, Five groups of metal cross lines are embedded in the module one, one of which is located at the center of the module one, and the other four groups are uniformly distributed around the center of the module one.

4. The phantom for CT simulator quality control detection of claim 2, wherein, The module two is integrated with a spatial integrity, layer thickness detection device, and a CT value linearity detection device.

5. The phantom for CT simulator quality control detection of claim 2, wherein, The module three is integrated with a low contrast resolution and high contrast resolution detection device.

6. The phantom for CT simulator quality control detection of claim 2, wherein, The module four is internally provided with a plurality of phantom inserts with different electron densities.

7. Phantom for CT simulator quality control detection according to claim 6, characterized in that, The plurality of phantom inserts at least include density phantom inserts of an inhalation lung, an exhalation lung, fat, breast, muscle, liver and four different density bone tissues.

8. The phantom for CT simulator quality control detection of claim 2, wherein, The module five is hollow, and a sealable water injection hole is arranged at the top of the module.

9. The phantom for CT simulator quality control detection of claim 2, wherein, The peripheral side of each module is respectively provided with four groups of cross mark lines, and the four groups of cross mark lines are uniformly distributed around the center of the corresponding module.

10. The phantom for CT simulator quality control detection of claim 2, wherein, The outer surfaces of the two support structures are respectively provided with cross mark lines corresponding to the center of the phantom body.

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