A simulation phantom for verification of setup correction accuracy metrics for an x-igrt device

Abstract

The utility model relates to a kind of simulation phantom for the positioning correction precision index verification of X-IGRT equipment, belong to medical field.The simulation phantom includes mark point square mould, spinal cord simulation structure, soft tissue simulation structure, and soft tissue simulation structure includes soft tissue lower half, soft tissue upper half;Upper end surface of soft tissue lower half is provided with upper cavity, and lower end surface of soft tissue upper half is formed with lower cavity, and upper cavity and lower cavity enclose closed cavity for accommodating mark point square mould.The utility model is equipped with skeletal simulation structure and mark point square mould of embedding 5 mark points simultaneously, meet the demand of the precision index test of hospital and manufacturer to carry out skeletal / gray scale registration and mark point registration simultaneously;Easy to process, assemble, avoid metal artifact on the basis of guaranteeing size, ensure image quality.

Description

Technical Field

[0001] This utility model relates to the field of medical technology, specifically a simulation model for verifying the positioning and calibration accuracy of X-IGRT equipment. Background Technology

[0002] X-IGRT (Image-Guided Radiotherapy) is a device used for radiotherapy. Its core function is to guide and adjust the implementation of radiotherapy through X-ray imaging technology to improve the accuracy and safety of treatment.

[0003] With the development of image-guided radiotherapy technology, manufacturers need phantoms to verify the accuracy indicators required by standards during product registration and testing. Simultaneously, hospitals also need simulation phantoms to accept the accuracy indicators of their equipment. Currently, the mainstream image-guided registration algorithms used in clinical practice include bone / grayscale registration methods and marker registration methods. Phantoms need to be compatible with the accuracy verification of these registration methods.

[0004] The following problems may arise when using the phantom:

[0005] 1. There are molds on the market made of uniform materials or with simulated structures. However, considering the requirements of hospitals for equipment acceptance, the use of molds made of uniform materials is questioned as not conforming to actual clinical conditions.

[0006] 2. Some molds have embedded markers, commonly made of lead dots, which present the following problems:

[0007] 2.1 If the diameter is small (e.g., 1mm), it is difficult to give an accurate location in the CT scan image, affecting the accuracy;

[0008] 2.2 If the diameter is large (e.g., 3mm), there will be more radioactive artifacts in the CT scan image, resulting in poor image quality and affecting the positional accuracy.

[0009] Based on this, the present utility model is proposed. Utility Model Content

[0010] This invention addresses the shortcomings of existing technologies by providing a simulation model for verifying the positioning and calibration accuracy of X-IGRT equipment. The technical solution is as follows:

[0011] A simulation phantom for verifying the positioning accuracy of an X-IGRT device includes a simulation phantom body. The simulation phantom body includes a marker point square phantom, a spinal simulation structure, and a soft tissue simulation structure. The soft tissue simulation structure includes a lower soft tissue portion and an upper soft tissue portion that is attached to the lower soft tissue portion. The upper end face of the lower soft tissue portion is provided with an inwardly recessed upper cavity, and the lower end face of the upper soft tissue portion forms an inwardly recessed lower cavity. The upper cavity and the lower cavity match each other, and the upper cavity and the lower cavity enclose a closed cavity for accommodating the marker point square phantom.

[0012] As a further embodiment of this utility model, the marker square mold includes a central marker point, four surrounding marker points (one, two, three, and four) embedded inside the marker square mold. The four surrounding marker points are located on the four corner sidewalls of the marker square mold and are not coplanar.

[0013] As a further embodiment of this invention, the lower half of the soft tissue covers the spinal simulation structure.

[0014] As a further embodiment of this utility model, the center marker point, the first marker point around the square mold, the second marker point around the square mold, the third marker point around the square mold, and the fourth marker point around the square mold are all made of ceramic beads with a diameter of 2-4 mm.

[0015] As a further embodiment of this invention, the marker square mold is made of a block with a side length exceeding 60mm.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] 1. It features both a skeletal simulation structure and a marker square model with 5 embedded marker points, meeting the accuracy requirements of hospitals and manufacturers for skeletal / grayscale registration and marker point registration testing.

[0018] 2. The five marker points are made using an independent processing method, avoiding the need to directly drill holes in the mold body and then implant the marker points, thus ensuring the accuracy of the implanted points.

[0019] 3. Use ceramic beads with a diameter of 2-4mm to mark the points. This will ensure the size of the markers while avoiding metal artifacts and guaranteeing image quality.

[0020] 4. The spinal simulation structure, marker point model, and soft tissue simulation structure are processed in separate blocks and then assembled one by one, which reduces the processing difficulty and facilitates standardized production. Attached Figure Description

[0021] Figure 1 This is a structural diagram of the simulation model used for verifying the positioning and calibration accuracy of X-IGRT equipment according to this utility model;

[0022] Figure 2 This is a schematic diagram of the assembled simulation model used for verifying the positioning accuracy index of X-IGRT equipment according to this utility model.

[0023] Figure 3 This is a schematic diagram of the marking point square model described in this utility model;

[0024] Figure 4 This is a schematic diagram of the lower half of the soft tissue described in this utility model;

[0025] Figure 5 This is a schematic diagram of the upper part of the soft tissue described in this utility model. Detailed Implementation

[0026] The present invention will be described in detail below with reference to specific embodiments. These embodiments are merely some, not all, implementations of the present invention. All other implementations obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] This invention proposes a simulation model that can be used to verify the positioning accuracy in various X-IGRT devices, such as CBCT (cone-beam CT, a medical imaging device that uses cone-beam X-rays for three-dimensional tomography), EPD (electronic field imaging device, a device used for patient positioning verification and dose monitoring in radiotherapy), and dual-column DR (a common medical imaging device).

[0029] like Figures 1-5 As shown, the simulation phantom used for accuracy verification of X-ray image-guided equipment includes a simulation phantom body 1. The simulation phantom body 1 includes a marker point square phantom 11, a spinal simulation structure 12, a lower half of soft tissue 13, and an upper half of soft tissue 14 that is attached to the lower half of soft tissue 13. The lower half of soft tissue 13 and the upper half of soft tissue 14 constitute the soft tissue simulation structure. The upper end face of the lower half of soft tissue 13 forms an inwardly recessed upper cavity 131, and the lower end face of the upper half of soft tissue 14 forms an inwardly recessed lower cavity 141. The upper cavity 131 and the lower cavity 141 match and enclose a closed cavity; the marker point square phantom 11 is removably inserted into the cavity.

[0030] The marker mold 11 includes a central marker 111, four surrounding markers 112, 113, 114, and 115 embedded inside the mold. These four markers are located on the four corner sidewalls of the marker mold 11 and are not coplanar. The four markers are equidistant from the central marker 111 and are distributed asymmetrically at the four corners.

[0031] The spinal simulation structure 12 mimics the spine of a real patient. In this embodiment, the spinal simulation structure 12 has more than five vertebral segments, including the vertebral column and spinous processes. Each segment is individually fabricated to a density greater than 2 g / cm³. 3 Non-metallic materials (such as polytetrafluoroethylene) are 3D printed and then assembled into multiple sections.

[0032] In this embodiment, the lower half 13 and the upper half 14 of the soft tissue are selected with a density of 1 ± 0.2 g / cm³. 3 Non-metallic materials (such as plexiglass) are processed by casting. During the casting of the lower half 13 of the soft tissue, a spinal simulation structure 12 is embedded, so that the lower half 13 of the soft tissue covers the spinal simulation structure 12. After casting is completed, the upper cavity 131 and the lower cavity 141 are processed by cutting at corresponding positions on the lower half 13 and the upper half 14 of the soft tissue.

[0033] In this embodiment, the marker mold 11 is also made of plexiglass and processed into a cube with a side length exceeding 60mm (e.g., 64mm) by casting. Holes are then drilled at the corresponding positions of its center and four corners, which are neither horizontal nor vertical, with a hole diameter of 2~4mm (e.g., 3mm). Then, ceramic beads (e.g., high-purity zirconium oxide with a diameter of 2~4mm (e.g., 3mm) are embedded in the holes to create the center marker 111, the first four-sided marker 112, the second four-sided marker 113, the third four-sided marker 114, and the fourth four-sided marker 115 of the marker mold.

[0034] The specific steps for using it are as follows:

[0035] 1. The image guidance center point can be set on the center marker point 111 of the marker point square model, and it can simultaneously support image guidance using several methods such as skeleton registration, grayscale registration and marker point registration.

[0036] 2. Skeletal registration and grayscale registration methods: Image registration is performed using the skeletal or grayscale structures in the vicinity of the center marker point 111 of the marker square model.

[0037] 3. Marker point registration: Use the center marker point 111 of the marker point square model and the four non-coplanar marker points distributed around the four sides of the marker point square model, namely, marker point one 112, marker point two 113, marker point three 114, and marker point four 115, to perform image registration.

[0038] 4. At the same time, the simulation model body 1 can be kept in the same position, and image registration can be performed using bone registration, grayscale registration and marker point registration methods. The consistency of accuracy can be verified by comparing the different registration methods.

[0039] Furthermore, it should be understood that those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A simulation phantom for verifying the positioning accuracy of X-IGRT equipment, comprising a simulation phantom body, characterized in that: The simulation phantom body includes a marker point square model, a spinal simulation structure, and a soft tissue simulation structure. The soft tissue simulation structure includes a lower half of soft tissue and an upper half of soft tissue that fits into the lower half of soft tissue. The upper end face of the lower half of soft tissue is provided with an inwardly recessed upper cavity, and the lower end face of the upper half of soft tissue forms an inwardly recessed lower cavity. The upper cavity and the lower cavity match each other, and the upper cavity and the lower cavity enclose a closed cavity for accommodating the marker point square model.

2. The simulation model for verifying the positioning accuracy index of X-IGRT equipment according to claim 1, characterized in that: The marker square mold includes a center marker point implanted inside the marker square mold, and four surrounding marker points: marker point one, marker point two, marker point three, and marker point four. The four surrounding marker points are located on the four corner sidewalls of the marker square mold and are not coplanar.

3. The simulation model for verifying the positioning accuracy index of X-IGRT equipment according to claim 1, characterized in that: The lower half of the soft tissue covers the simulated spinal structure.

4. The simulation model for verifying the positioning accuracy index of X-IGRT equipment according to claim 2, characterized in that: The center marker, the first marker, the second marker, the third marker, and the fourth marker on the perimeter of the square mold are all made of ceramic beads with a diameter of 2-4 mm.

5. The simulation model for verifying the positioning accuracy index of X-IGRT equipment according to claim 1, characterized in that: The marker square mold is made of a block with a side length of more than 60mm.

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