A CT-MRI same-position radiotherapy simulation positioning device

Abstract

The present invention provides a CT-MRI same-position radiotherapy simulation positioning device, which includes a headrest, a first positioning member, a second positioning member, a U-shaped head model and a position fixing plate. The first positioning member and the second positioning member have the same structure, and the headrest can be detachably connected to both of them. The first positioning member is fixed on the position placement plate on the CT simulation positioning machine, and the second positioning member is fixed on the front center of the position fixing plate. The U-shaped head model is detachably connected to the position fixing plate and the position placement plate, respectively, and the connection positions correspond one to one. The headrest and the U-shaped head model are both thermoplastic molding parts; the front of the position fixing plate is a plane and the back is provided with an adapter, and the adapter is adapted to the bottom surface of the head and neck combined coil used on the nuclear magnetic resonance scanner and is surface-fitted. The present invention allows the position of the CT image and the MRI image to be consistent when they are acquired, so that the registration and fusion effect of the MRI image and the CT image is more excellent, thereby improving the accuracy of the target area delineation to improve the radiotherapy effect.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a CT-MRI same-body radiotherapy simulation positioning device. Background Art

[0002] Tumor radiotherapy is a local treatment method that uses radiation to treat tumors. It requires accurate positioning and delineation of the tumor target area and its size. Among them, CT (Computed Tomography) images, MRI (Magnetic Resonance Imaging) images and image registration and fusion technology are commonly used to improve the accuracy of target area delineation.

[0003] However, the patient's body position when scanning on a CT simulation positioning machine to generate a CT image is different from that when scanning on a magnetic resonance imaging scanner to generate an MRI image, which affects the accuracy of target area delineation. Summary of the invention

[0004] In order to solve the above problems in the prior art, the present invention provides a CT-MRI same-position radiotherapy simulation positioning device, which can improve the accuracy of target area delineation.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] In a first aspect, the present invention provides a CT-MRI same-position radiotherapy simulation positioning device, comprising a headrest, a first positioning member, a second positioning member, a U-shaped head mold and a position fixing plate, wherein the headrest is detachably connected to the first positioning member and detachably connected to the second positioning member, the first positioning member and the second positioning member have the same structure, the first positioning member is fixed to the position placement plate on the CT simulation positioning machine, the second positioning member is fixed to the front center position of the position fixing plate, the U-shaped head mold is detachably connected to the position fixing plate and the position placement plate respectively, and the connection positions correspond one to one, the headrest and the U-shaped head mold are both thermoplastic molding members, the headrest is formed by a patient lying on a thermoplastic material above the first positioning member, and the U-shaped head mold is formed by a thermoplastic film stretched downward from the face of a patient lying on the headrest and fixed on the position placement plate;

[0007] The front side of the body position fixing plate is a plane and the back side is provided with an adaptor, and the adaptor is matched with the bottom side of the head and neck combined coil used on the nuclear magnetic resonance scanner and is surface-fitted.

[0008] The beneficial effect of the present invention is that the adapter is used to fit the bottom surface of the head and neck combined coil used on the nuclear magnetic resonance scanner, so that the upper surface of the position fixing plate is set horizontally. At this time, the position placement plate and the position fixing plate on the CT simulation positioning machine are also provided with a headrest and a U-shaped head model for fixing the patient's position, so that the position of the CT image and the MRI image when they are acquired is consistent, so that the registration and fusion effect of the MRI image and the CT image is more excellent, thereby improving the accuracy of the target area delineation and improving the radiotherapy effect.

[0009] Optionally, a spirit level is provided on the front of the body position fixing plate, and a water column is embedded in the center of the back of the body position fixing plate. When the headrest is connected with the second positioning member, the middle axis of the water column coincides with the middle axis of the headrest in vertical projection.

[0010] According to the above description, the level is used to ensure that the position fixation board is placed horizontally, thereby creating a plane environment identical to the position placement board, and the verticality of the water column in the scanning positioning image is used to ensure the horizontal verticality of the tomographic scanning line, thereby further improving the registration and fusion effect of the MRI image and the CT image.

[0011] Optionally, both the first positioning member and the second positioning member are positioning blocks that imitate the curve of the head and neck.

[0012] Optionally, a first positioning plate is provided below the first positioning member, and a second positioning plate is provided below the second positioning member, the first positioning member is fixed to a body position placement plate on a CT simulation positioning machine through the first positioning plate, and the second positioning member is fixed to a front center position of the body position fixing plate through the second positioning plate;

[0013] The U-shaped head mold is detachably connected to the body position fixing plate and the body position placing plate respectively, and is replaced by: the U-shaped head mold is detachably connected to the first positioning plate and the second positioning plate respectively.

[0014] Optionally, the coverage area of ​​the U-shaped head mold is from the head to the shoulders, which matches the edge size of the body positioning fixation plate.

[0015] According to the above description, the U-shaped head model covers an area from the head to the shoulders, so as to fix the upper body area of ​​the patient as much as possible, so that the body position of the CT image and the MRI image is consistent when they are acquired.

[0016] Optionally, a plurality of fixing holes are distributed on the edge of the U-shaped head mold, and snap fasteners are arranged in the fixing holes, and the snap fasteners are used to be detachably connected to the body position fixing plate and the body position placement plate respectively.

[0017] Optionally, the body position fixing plate is detachably connected to the adapter.

[0018] Optionally, the adapter is arranged on the back side of the body position fixing plate corresponding to the second positioning member, and a support member is further arranged on the back side of the body position fixing plate in an area extending outside the head and neck combined coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the cooperation between the first positioning member and the body positioning plate involved in an embodiment of the present invention;

[0020] Figure 2 It is a three-dimensional schematic diagram of a headrest, a first positioning member, a U-shaped head mold and a body positioning plate involved in an embodiment of the present invention;

[0021] Figure 3 It is a three-dimensional schematic diagram of a body position fixing plate, a second positioning member and an adapter member involved in an embodiment of the present invention;

[0022] Figure 4 It is a schematic diagram of the back side of the body position fixing plate involved in the embodiment of the present invention;

[0023] Figure 5 A schematic diagram of a scanning positioning image involved in an embodiment of the present invention;

[0024] Figure 6 Another implementation scheme of the U-shaped head mold involved in the embodiment of the present invention;

[0025] Figure 7 A schematic diagram of the comparison of a CT image and an MRI image obtained in an embodiment of the present invention;

[0026] Figure 8 A schematic diagram showing the comparison of a CT image and an MRI image obtained by the prior art;

[0027] Description of reference numerals:

[0028] 1. Headrest;

[0029] 2. first positioning member; 21. first positioning plate; 22. mounting hole;

[0030] 3. U-shaped head mold; 31. Fixing hole;

[0031] 4. Body position fixing board; 41. Level; 42. Water column;

[0032] 5. Adapters;

[0033] 6. second positioning member; 61. second positioning plate;

[0034] 7. Support parts;

[0035] 100. Positioning board. DETAILED DESCRIPTION

[0036] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0037] Embodiment 1

[0038] Please refer to Figures 1 to 7 A CT-MRI same-position radiotherapy simulation positioning device comprises a headrest 1, a first positioning member 2, a second positioning member 6, a U-shaped head model 3 and a position fixing plate 4. The headrest 1 is detachably connected to the first positioning member 2 and the second positioning member 6. The first positioning member 2 and the second positioning member 6 have the same structure. A first positioning plate 21 is arranged below the first positioning member 2, and a second positioning plate 61 is arranged below the second positioning member 6. The first positioning member 2 is fixed to a position placement plate 100 on a CT simulation positioning machine through the first positioning plate 21. For example, a cylindrical protrusion is provided on the position placement plate 100. The holes and the cylindrical protrusions are aligned at the corresponding positions of the first positioning plate 21, so that the two are kept fixed; the second positioning member 6 is fixed to the front center position of the body position fixing plate 4 through the second positioning plate 61, and the U-shaped head mold 3 is detachably connected to the first positioning plate 21 and the second positioning plate 61 respectively, and the connection positions correspond one to one. The headrest 1 and the U-shaped head mold 3 are both thermoplastic molding parts. The headrest 1 is molded on the thermoplastic material above the first positioning member 2, and the U-shaped head mold 3 is molded by stretching the thermoplastic film from the face down of the patient lying on the headrest 1 and fixing it on the body position placement plate 100.

[0039] The front side of the body position fixing plate 4 is a plane and the back side is provided with an adapter 5, which is adapted to and in surface contact with the bottom side of the head and neck combined coil used on the MRI scanner. Specifically, in this embodiment, the body position fixing plate 4 extends from the head to the shoulder, wherein the head and neck area is located in the head and neck combined coil, that is, the adapter 5 is arranged on the back side of the body position fixing plate 4 corresponding to the second positioning member 6, which is also the back side position of the body position fixing plate 4 located in the head and neck combined coil, and a support member 7 is also arranged on the back side of the body position fixing plate 4 in the area extending out of the head and neck combined coil. Figure 3 As shown, the support member 7 in this embodiment is a support block arranged on the left and right sides, and the support block is made of soft plastic or rubber.

[0040] Since the models of MRI scanners on the market are different, there are at least three types of bottom surfaces in MRI scanners using head-neck combined coils. For example, the bottom surface of the head-neck combined coil used in the GE3.0T superconducting MRI magnetic imaging examination equipment used in this embodiment is arc-shaped, and the adapter 5 is an arc-shaped plate that fits the arc-shaped bottom surface. Therefore, the body position fixing plate 4 in this embodiment is detachably connected to the adapter 5, and different types of head-neck combined coils can be replaced with different adapters 5. In this embodiment, it is necessary to select ABS plastic to design the body position fixing plate 4 according to the width and aperture size of the head-neck combined coil of the MRI scanner to connect the head-neck combined coil.

[0041] In this embodiment, a level 41 is provided on the front of the body position fixing plate 4, and a water column 42 is embedded in the center of the back of the body position fixing plate 4. When the headrest 1 is connected with the second positioning member 6, the middle axis of the water column 42 coincides with the middle axis of the headrest 1 in vertical projection. Figure 3 As shown, the horizontal placement of the body position fixing plate 4 is ensured by providing a level gauge 41 in both the horizontal and vertical directions, thereby creating a plane environment identical to the body position placing plate 100. At this time, the level gauge 41 is placed at the edge of the body position fixing plate 4 away from the second positioning member 6, which corresponds to the position of the patient's arm. When the patient lies down, the patient only needs to slightly lift his arm to allow the nursing staff to observe the situation of the level gauge 41.

[0042] like Figure 6 As shown, there is a long column on the right side of the patient's head, which is the development of the water column 42 in the scanning positioning image, and the multiple horizontal lines with arrows on the patient's head are assumed tomographic scanning lines. When the water column 42 is not vertical in the scanning positioning image, the tomographic scanning line does not scan the patient's head vertically, which will affect the registration and fusion effect of the MRI and CT images. Therefore, the verticality of the tomographic scanning line is ensured by the verticality of the water column 42 in the scanning positioning image, thereby further improving the registration and fusion effect of the MRI image and the CT image.

[0043] In this embodiment, the first positioning member 2 and the second positioning member 6 are both positioning blocks that imitate the curve of the head and neck. The detachable connection between the headrest 1 and the first positioning member 2 and the detachable connection between the headrest 1 and the second positioning member 6 are both snap connections. Since the thermoplastic material is placed on the first positioning member 2 in advance, the positioning block that imitates the curve of the head and neck can save consumables and is easy to disassemble.

[0044] like Figure 2 and Figure 6 It is a different implementation of the U-shaped head mold 3. Figure 2 The coverage area of ​​the middle U-shaped head mold 3 is only the head. Figure 6The coverage area of ​​the middle U-shaped head mold 3 is from the head to the shoulder, which matches the edge size of the position fixing plate 4. Meanwhile, in other embodiments, the coverage area of ​​the U-shaped head mold 3 can also wrap the head and neck. Therefore, the U-shaped head mold 3 is used to fix the upper body area of ​​the patient so that the body position of the CT image and the MRI image is consistent when they are acquired.

[0045] In this embodiment, a plurality of fixing holes 31 are distributed on the edge of the U-shaped head mold 3, and a buckle is disposed in the fixing hole 31, and the buckle is used to detachably connect with the first positioning plate 21 and the second positioning plate 61. Figure 2 The top of the middle U-shaped head mold 3 has two fixing holes 31, and one is provided on each side of the bottom. Figure 6 There are two fixing holes 31 on the top, two fixing holes 31 on each side of the neck, and two fixing holes 31 on each side of the shoulder. Correspondingly, corresponding mounting holes 22 are also provided on the first positioning plate 21 and the second positioning plate 61 for buckling connection with the buckle.

[0046] In other embodiments, it is possible to consider not setting the first positioning plate 21 and the second positioning plate 61. In this case, the first positioning member 2 is fixed on the position placement plate 100 on the CT simulation positioning machine, and the second positioning member 6 is fixed on the front center of the position fixing plate 4. The U-shaped head mold 3 is detachably connected to the position fixing plate 4 and the position placement plate 100, and the connection positions correspond one to one. In this case, the mounting holes 22 are set on the position placement plate 100 and the position fixing plate 4. In other words, the buckles on the U-shaped head mold 3 can be detachably connected to the mounting holes 22 on the first positioning plate 21 and the second positioning plate 61, and can also be detachably connected to the position fixing plate 4 and the position placement plate 100. Compared with the latter, the former is more compatible with the application scenarios where the nuclear magnetic coil is relatively narrow, and the effect is better.

[0047] The working principle of this embodiment is as follows:

[0048] S1. The patient lies on the body position placement board 100 on the CT simulation positioning machine in a supine position, and the patient's head contacts the thermoplastic material above the first positioning member 2. After the thermoplastic material is cooled and formed, a headrest 1 is obtained. The patient lying on the headrest 1 is stretched downward from the face using a thermoplastic film and fixed on the body position placement board 100. After the thermoplastic film is cooled and formed, a U-shaped head mold 3 is obtained.

[0049] The thermoplastic material is first heated to 35-50°C and then coated on the first positioning member 2. At this time, the patient's head rests on the thermoplastic material, and after the thermoplastic material cools down, a headrest 1 suitable for the patient is formed. At the same time, after the thermoplastic film is heated to 35-50°C, the patient lying on the headrest 1 is stretched downward from the face to form a head mold suitable for the patient's face, and then stretched downward and fixed to the body positioning plate 100 through a buckle, and after waiting for the thermoplastic film to cool down, a U-shaped head mold 3 suitable for the patient is formed.

[0050] S2, the patient lies on the headrest 1 in a supine position, the U-shaped head model 3 covers the patient's face and is fixed to the body positioning plate 100, and is sent to the CT simulation positioning machine for CT positioning scanning, and the scanned CT image is transmitted to the radiotherapy planning system;

[0051] S3, fit the adapter 5 on the body position fixing plate 4 with the bottom surface of the head and neck combined coil used in the MRI scanner, buckle the headrest 1 on the second positioning piece 6 of the body position fixing plate 4, and the patient lies on the headrest 1 in the same supine position as in CT positioning, and cover the U-shaped head model 3 on the patient's face and fix it to the body position fixing plate 4;

[0052] S4, when the front side of the body position fixing plate 4 is in a horizontal position, the head and neck combined coil is covered and the body position fixing plate 4 is sent into a nuclear magnetic resonance scanner for nuclear magnetic resonance simulation positioning scanning, and the MRI image obtained by the scanning is transmitted to the radiotherapy planning system;

[0053] In this embodiment, in step S4, the front side of the body position fixing plate 4 is in a horizontal position, which includes:

[0054] Adjust the body position fixing plate 4 by observing the level 41 so that the front side of the body position fixing plate 4 is in a horizontal position;

[0055] When the patient lies on the body position fixing plate 4 , the patient only needs to slightly lift his arms so that the nursing staff can observe the situation of the level 41 .

[0056] Therefore, in step S4 , the body position fixing plate 4 simulates the effect of the body position placing plate 100 .

[0057] In this embodiment, in step S4, transmitting the scanned MRI image to the radiotherapy planning system includes:

[0058] Determine whether the water column 42 in the scanning positioning image is vertical. If so, transmit the MRI image obtained by subsequent scanning to the radiotherapy planning system. Otherwise, adjust the patient's position until the water column 42 in the scanning positioning image is vertical, and then transmit the MRI image obtained by subsequent scanning to the radiotherapy planning system.

[0059] Therefore, the body position in the MRI scanner in step S4 and the body position in the CT simulation positioning machine in step S2 are ensured to be consistent during scanning through the horizontal body position fixing plate 4, the level 41 and water column 42 thereon, the headrest 1 and the U-shaped head model 3 adapted to the user.

[0060] S5. Perform image registration and target area delineation on the CT image and MRI image for use in radiotherapy.

[0061] In this embodiment, the thermoplastic material is baked in an oven, and the thermoplastic film is softened by heating with water.

[0062] In combination with the first embodiment, it can be seen that this embodiment has the following three improvements:

[0063] 1. Pass Figure 7 It can be seen that the MRI image obtained by this embodiment is clear, the image quality is not affected by the device, and the registration and fusion effect with the CT image is good. The fused image can clearly show the position and size of the tumor target area, while the MRI image obtained by the prior art is not good. Figure 8 , where the two circles at the same position in the upper and lower figures show obvious differences, that is, there is a large misalignment between the MRI image and the CT image during registration, and the registration and fusion effect is poor.

[0064] When scoring the image registration, the overlap rate (Dice coefficient, a set similarity measurement function) and Hausdorff distance (HD) algorithm are used to evaluate the accuracy of the registration. In the prior art, the scores of MRI images and CT images before fusion are usually 30 to 40 points, and the scores after fusion by software are usually 60 to 70 points, while in this embodiment, the scores of MRI images and CT images before fusion are usually 80 to 90 points, and the scores after fusion by software are usually above 90 points. Therefore, in this embodiment, the positions of CT images and MRI images when they are acquired are kept consistent, so that the registration and fusion effect of MRI images and CT images is more excellent, thereby improving the accuracy of target area delineation and improving the effect of radiotherapy.

[0065] 2. In order to achieve consistency between MRI images and CT images, it is necessary to either introduce the latest MRI simulation positioning machine worth 20 million yuan or spend nearly 2 million yuan to modify the MRI bed and repurchase the matching coil. However, this embodiment uses the existing head and neck combined coil and only adds a body position fixing plate 4 that matches the bottom of the head and neck combined coil. The hospital does not need to modify the MRI bed or repurchase the matching coil. The body position fixing plate 4 and consumables cost only a few thousand yuan, so the modification cost can be greatly reduced.

[0066] 3. The present invention places a body position fixing plate 4 in the head and neck combined coil of the MRI scanner, buckles the headrest 1 corresponding to the patient, lets the patient lie on it and buckles the U-shaped head mold 3, and then performs horizontal adjustment to perform MRI scanning. Compared with conventional methods, it only takes less than one minute longer. Therefore, the device of this embodiment has greater practical value and feasibility.

[0067] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0068] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0069] In the present invention, unless otherwise clearly specified and limited, when a first feature is “on” or “below” a second feature, it may be that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, when a first feature is “above”, “above” or “above” a second feature, it may be that the first feature is directly above or obliquely above the second feature, or it may simply mean that the first feature is higher in level than the second feature. When a first feature is “below”, “below” or “below” a second feature, it may be that the first feature is directly below or obliquely below the second feature, or it may simply mean that the first feature is lower in level than the second feature.

[0070] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0071] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A CT-MRI same-position radiotherapy simulation positioning device, characterized in that: The invention comprises a headrest, a first positioning member, a second positioning member, a U-shaped head mold and a body position fixing plate, wherein the headrest is detachably connected to the first positioning member and the second positioning member, the first positioning member and the second positioning member have the same structure, the first positioning member is fixed to the body position placement plate on the CT simulation positioning machine, the second positioning member is fixed to the front center position of the body position fixing plate, the U-shaped head mold is detachably connected to the body position fixing plate and the body position placement plate respectively, and the connection positions correspond one to one, the headrest and the U-shaped head mold are both thermoplastic molding members, the headrest is formed by a patient lying on the thermoplastic material above the first positioning member, and the U-shaped head mold is formed by a thermoplastic film stretched downward from the face of a patient lying on the headrest and fixed on the body position placement plate; The front side of the body position fixing plate is a plane and the back side is provided with an adapter, and the adapter is adapted to and surface-fitted with the bottom side of the head and neck combined coil used on the nuclear magnetic resonance scanner; A spirit level is provided on the front of the body position fixing plate, and a water column is embedded in the center of the back of the body position fixing plate. When the headrest is connected with the second positioning member, the middle axis of the water column coincides with the middle axis of the headrest in vertical projection.

2. A CT-MRI same-body radiotherapy simulation positioning device according to claim 1, characterized in that: The first positioning member and the second positioning member are both positioning blocks that imitate the curve of the head and neck.

3. A CT-MRI same-body radiotherapy simulation positioning device according to claim 2, characterized in that: A first positioning plate is provided below the first positioning member, and a second positioning plate is provided below the second positioning member. The first positioning member is fixed to a body position placement plate on a CT simulation positioning machine through the first positioning plate, and the second positioning member is fixed to a front center position of the body position fixing plate through the second positioning plate; The U-shaped head mold is detachably connected to the body position fixing plate and the body position placing plate respectively, and is replaced by: the U-shaped head mold is detachably connected to the first positioning plate and the second positioning plate respectively.

4. The CT-MRI same-body radiotherapy simulation positioning device according to claim 1, characterized in that: The U-shaped head mold covers an area from the head to the shoulders, which matches the edge size of the body position fixing plate.

5. The CT-MRI same-body radiotherapy simulation positioning device according to claim 1, characterized in that: A plurality of fixing holes are distributed on the edge of the U-shaped head mold, and buckles are arranged in the fixing holes. The buckles are used to be detachably connected to the body position fixing plate and the body position placement plate respectively.

6. The CT-MRI same-body radiotherapy simulation positioning device according to claim 1, characterized in that: The body position fixing plate is detachably connected to the adapter.

7. The CT-MRI same-body radiotherapy simulation positioning device according to claim 1, characterized in that: The adapter is arranged on the back side of the body position fixing plate corresponding to the second positioning member, and a support member is also arranged on the back side of the body position fixing plate in an area extending out of the head and neck combined coil.

Images