CT imaging apparatus and radiotherapy device

Abstract

The application provides a CT imaging device and a radiotherapy equipment. In the CT imaging device, the opening size of a collimator is adjusted so that the emitted X-ray beam can be switched between a cone beam and a fan beam, and when the cone beam is generated, data acquisition is performed by using a first detector, and when the fan beam is generated, data acquisition is performed by using a second detector. In this way, the switching between the cone beam imaging mode and the fan beam imaging mode is realized under the condition of sharing the same imaging radiation source, so that the same CT imaging device simultaneously integrates the cone beam imaging function and the fan beam imaging function, which not only can save the occupied space of the equipment, but also greatly reduces the system cost, and improves the use flexibility under different CT imaging modes.

Description

Technical Field

[0001] This invention relates to the field of medical imaging technology, and in particular to a CT imaging device and a radiotherapy equipment. Background Technology

[0002] Radiotherapy plays an increasingly important role in cancer treatment. In order to irradiate the tumor site more precisely and to better protect the critical organs around the tumor, a variety of imaging techniques are applied in the field of image-guided radiotherapy (IGRT), such as kV cone-beam CT (kV-CBCT) and kV fan-beam CT (kV-FBCT).

[0003] Cone-beam computed tomography (CBCT) uses an X-ray tube and area array detectors that rotate around the irradiated object in a single revolution to acquire projection data. The acquired image data is then reconstructed to obtain a three-dimensional image. Fan-beam computed tomography (FBCT), on the other hand, uses a linear array detector to acquire image data. The acquired image data is then reconstructed to obtain a two-dimensional image, requiring the stacking of multiple consecutive two-dimensional slices to form a three-dimensional image. In other words, CBCT has a larger scanning range, enabling rapid three-dimensional imaging; however, its image noise is also higher, resulting in relatively lower image quality. Conversely, FBCT has a smaller scanning range, but it achieves better two-dimensional imaging quality.

[0004] It is evident that CBCT and FBCT each possess distinct advantages, and in practical applications, different modes are selected for scanning based on specific needs. Currently, CBCT and FBCT are difficult to integrate into a single machine; different imaging systems are typically housed in separate devices. This not only requires significant space but also necessitates the independent configuration of components for each imaging system, greatly increasing system costs. Summary of the Invention

[0005] The purpose of this invention is to provide a CT imaging device to solve the problem that existing CT imaging devices are difficult to integrate cone-beam imaging mode and fan-beam imaging mode in the same machine.

[0006] To address the aforementioned technical problems, the present invention provides a CT imaging apparatus, comprising: an imaging radiation source for generating an imaging X-ray beam; a collimator located on the beam-emission side of the imaging radiation source and having an adjustable-sized opening for limiting the switching of the emitted X-ray beam between a cone beam and a fan beam; and a first detector and a second detector, the first detector being used to receive the X-rays of the cone beam when the cone beam is generated, and the second detector being used to receive the X-rays of the fan beam when the fan beam is generated.

[0007] Optionally, the first detector and the second detector are arranged along the X-ray beam path direction, and at least the detector arranged in front is movable, which can move back and forth to block or expose the detector arranged behind.

[0008] Optionally, the first detector is arranged in front of the second detector and is movable.

[0009] Optionally, the detectors arranged in front are movable at least axially within the scanning field of view of the CT imaging device.

[0010] Optionally, the aperture size of the collimator may be adjustable at least axially in the scanning field of view of the CT imaging device to switch between cone-beam and fan-beam configurations.

[0011] Optionally, the first detector is an area array detector, and the second detector is a linear array detector.

[0012] Another object of the present invention is to provide a radiotherapy device comprising a CT imaging apparatus as described above; and the radiotherapy device further comprising a therapeutic radiation source for emitting a therapeutic beam.

[0013] Optionally, the radiotherapy device further includes a treatment beam detector, which is disposed opposite to the treatment radiation source for receiving the treatment beam.

[0014] Optionally, the first detector in the CT imaging apparatus is movably configured and can move between a position opposite to the imaging radiation source and a position opposite to the treatment radiation source to receive a cone beam of X-rays when facing the imaging radiation source and a treatment beam when facing the treatment radiation source.

[0015] Optionally, the center of the imaging area of ​​the CT imaging device coincides with the center of the treatment area of ​​the radiotherapy device.

[0016] The CT imaging device provided by this invention includes a collimator with an adjustable aperture size. This allows the emitted X-ray beam to switch between cone-beam and fan-beam modes by adjusting the collimator's aperture size when sharing the same imaging radiation source. It also includes a first detector for receiving the cone-beam beam and a second detector for receiving the fan-beam beam. Thus, it enables switching between cone-beam and fan-beam imaging modes while sharing the same imaging radiation source. This allows a single CT imaging device to integrate both cone-beam and fan-beam imaging functions, saving space, significantly reducing system costs, and improving the flexibility of use under different CT imaging modes. Attached Figure Description

[0017] Figure 1 This is a front view of a CT imaging device in cone-beam imaging mode according to an embodiment of the present invention.

[0018] Figure 2 for Figure 1 The CT imaging apparatus shown is a cross-sectional view along the XZ plane in cone-beam imaging mode.

[0019] Figure 3 This is a front view of a CT imaging device in fan-beam imaging mode according to an embodiment of the present invention.

[0020] Figure 4 for Figure 3 The CT imaging apparatus shown is a cross-sectional view along the XZ plane in fan-beam imaging mode.

[0021] Figure 5 This is a front view of the CT imaging device of one of the radiotherapy devices in cone-beam imaging mode according to an embodiment of the present invention.

[0022] Figure 6 This is a front view of the CT imaging device of one of the radiotherapy devices in one embodiment of the present invention in fan-beam imaging mode.

[0023] Figure 7 In another embodiment of the present invention, the first detector in the CT imaging device of a radiotherapy device can be used for the main view of the treatment beam detector.

[0024] The accompanying figure is labeled as follows:

[0025] 110 - Imaging reflection source;

[0026] 120-collimator;

[0027] 130a - First Detector;

[0028] 130b - Second detector;

[0029] 210 - Therapeutic reflex source;

[0030] 220-Therapeutic Beam Detector;

[0031] 300-Rack. Detailed Implementation

[0032] As described in the background section, in the prior art, fan-beam CT and cone-beam CT are installed in different devices, which not only requires a large space and is also costly, but also requires the fan-beam CT scanning and imaging to be performed separately in different devices, making the application quite cumbersome.

[0033] Therefore, the present invention provides a CT imaging device that integrates both cone-beam imaging and fan-beam imaging functions. Specifically, the CT imaging device provided by the present invention includes: an imaging radiation source for generating an X-ray beam for imaging; a collimator with an adjustable aperture size; and a first detector for receiving the cone beam when generating the cone beam, and a second detector for receiving the fan beam when generating the fan beam.

[0034] That is, in the CT imaging apparatus provided by the present invention, its collimator has an adjustable opening, thereby enabling the emitted X-ray beam to switch between a cone beam and a fan beam by adjusting the opening size of the collimator while sharing the same imaging radiation source; and, when emitting a cone beam, a first detector (e.g., an area array detector) can be used to receive the X-rays of the cone beam, while when emitting a fan beam, a second detector (e.g., a linear array detector) can be used to receive the X-rays of the fan beam. Thus, different imaging modes can be switched using the same imaging radiation source within the same device.

[0035] The following combination Figures 1-4 The CT imaging device and radiotherapy equipment proposed in this invention will be further described in detail with specific embodiments. Figure 1 This is a front view of a CT imaging device in cone-beam imaging mode according to an embodiment of the present invention; Figure 2 for Figure 1 The CT imaging apparatus shown is a cross-sectional view along the XZ plane in cone-beam imaging mode; Figure 3 This is a front view of a CT imaging device in fan-beam imaging mode according to an embodiment of the present invention; Figure 4 for Figure 3 The illustrated CT imaging apparatus is a cross-sectional view along the XZ plane in fan-beam imaging mode. The advantages and features of the invention will become clearer from the following description. It should be noted that the figures are all in a very simplified form and use non-precise scales, intended only to facilitate and clarify the illustration of embodiments of the invention. Relative terms such as “above,” “below,” “top,” “bottom,” “upper,” and “lower” shown in the figures are used to describe the relationships between various elements. These relative terms are intended to cover different orientations of elements other than those depicted in the figures. For example, if the apparatus is inverted relative to the view in the figures, an element described, for example, as being “above” another element would now be below that element.

[0036] Combination Figures 1-4 As shown, the CT imaging device includes: an imaging radiation source 110, a collimator 120, a first detector 130a, and a second detector 130b.

[0037] The imaging radiation source 110 is used to generate X-rays for imaging. In a specific example, the imaging radiation source 110 can be a CT tube, which includes a cathode and an anode. The cathode has an electron generation source to generate electrons and emit them towards the anode target in the anode to radiate X-rays. The electron generation source in the cathode can be a hot cathode, such as a filament (specifically, a tungsten filament or a molybdenum filament); the electron generation source can also be a cold cathode that emits electrons through a field effect, such as a carbon nanotube or a silicon nanoneedle. Furthermore, the anode target in the anode can be made of elements with high atomic numbers, such as tungsten or molybdenum.

[0038] Furthermore, the CT tube is also connected to a high-voltage generator (not shown in the figure), which provides high voltage to the cathode or anode of the CT tube. In this embodiment, the electrical signal supplied to the CT tube can be adjusted according to the specific imaging mode performed by the CT imaging device. For example, when the CT imaging device performs fan-beam imaging, the voltage supplied to the CT tube can be reduced to decrease the discharge power, thereby reducing the generated X-rays; however, when the CT imaging device performs cone-beam imaging, the voltage supplied to the CT tube can be increased to increase the discharge power, thereby generating more X-rays to meet the requirements of cone-beam imaging.

[0039] Key reference Figure 2 and Figure 4 As shown, the collimator 120 is located on the beam-emission side of the imaging radiation source 110 and has an adjustable-sized opening for limiting the switching of the emitted X-ray beam between a cone beam and a fan beam. That is, when it is necessary to switch the cone X-ray beam to a fan X-ray beam, the size of the opening of the collimator 120 can be adjusted (e.g., decreasing the size of the opening in a predetermined direction) so that the emitted X-ray beam is a fan X-ray beam; or, when it is necessary to switch the fan X-ray beam to a cone X-ray beam, the size of the opening of the collimator 120 can be adjusted (e.g., increasing the size of the opening in a predetermined direction) so that the emitted X-ray beam is a cone X-ray beam.

[0040] In this embodiment, the scanning range of the cone-shaped X-ray beam is extended to a larger extent, at least axially, of the scanning field of view of the CT imaging device, compared to the scanning range of the fan-shaped X-ray beam (i.e., the scanning range of the cone-shaped X-ray beam has a larger area in the Z direction compared to the scanning range of the fan-shaped X-ray beam). Therefore, the size of the opening of the collimator 120 can be adjusted, at least axially, of the scanning field of view of the CT imaging device. Specifically, in cone-beam imaging mode, the collimator 120 can be configured to have a larger opening in the Z direction to restrict the cone-shaped beam; and in fan-shaped beam imaging mode, the collimator 120 can be configured to have a smaller opening in the Z direction to restrict the fan-shaped X-ray beam.

[0041] Continue to refer to Figures 1-4 As shown, the first detector 130a is used to receive the cone-shaped X-rays at the moment the cone-shaped beam is generated. That is, in the cone-beam imaging mode, the first detector 130a will be positioned relative to the imaging radiation source 110 and exposed within the scanning range of the cone-beam imaging mode to receive the cone-shaped X-rays. And, the second detector 130b is used to receive the fan-shaped X-rays at the moment the fan-shaped beam is generated. That is, in the fan-shaped beam imaging mode, the second detector 130b will be positioned relative to the imaging radiation source 110 and exposed within the scanning range of the fan-shaped beam imaging mode to receive the fan-shaped X-rays.

[0042] In an optional configuration, at least one of the first detector 130a and the second detector 130b may be movable, thereby allowing the first detector 130a and the second detector 130b to be alternately exposed within the scanning field of view of the CT imaging device.

[0043] For example, the first detector 130a and the second detector 130b are arranged along the X-ray beam path. In this case, at least the detector arranged in front can be movable, allowing it to move back and forth to block or expose the detector arranged behind. When the detector in front blocks the detector arranged behind, the detector in front is activated to receive the corresponding X-ray; conversely, when the detector arranged behind is exposed, it is activated to receive the corresponding X-ray. The detector in front is the one closer to the imaging radiation source 110. Furthermore, the detector arranged behind can be movable or fixed; there is no limitation here. For ease of explanation, a movable detector is defined as a movable detector. In this embodiment, the first detector 130a is a movable detector.

[0044] In this embodiment, the first detector 130a is positioned in front of the second detector 130b and is movable. See details for further information. Figure 1 and Figure 2 As shown, in cone-beam imaging mode, the first detector 130a will move to the relative position of the imaging radiation source 110 (at this time, the first detector 130a is correspondingly located within the scanning range of the cone beam) and block the second detector 130b. Then refer to... Figure 3 and Figure 4 As shown, in the fan-beam imaging mode, the first detector 130a moves out of the scanning range corresponding to the fan beam so that the second detector 130b is exposed to the relative position of the imaging radiation source 110. At this time, the second detector 130b is located within the scanning range of the fan beam.

[0045] Furthermore, in this embodiment, the first detector 130a for receiving cone-shaped X-ray beams is specifically a planar array detector (or a flat panel detector), and the second detector 130b for receiving fan-shaped X-ray beams is a linear array detector. In this embodiment, the planar array detector can specifically be a flat panel detector. Also, the linear array detector is specifically an arc-shaped detector, so that X-rays can be received perpendicularly or nearly perpendicularly by the arc-shaped detector, improving imaging accuracy.

[0046] As described above, the scanning range of the cone-shaped X-ray beam is extended to a greater extent, at least in the axial direction of the scanning field, compared to the scanning range of the fan-shaped X-ray beam. Therefore, the area of ​​the area array detector is larger than that of the linear array detector, at least in the axial direction of the scanning field (e.g., ...). Figure 2 and Figure 4 As shown, the first detector 130a has a larger area in the Z direction to satisfy the scanning field of view of the cone X-ray beam. Based on this, in this embodiment, by placing the first detector 130a in front of the second detector 130b, the first detector 130a can be closer to the imaging radiation source 110, thereby reducing the area of ​​the first detector 130a while satisfying the same scanning field of view, which is beneficial to further reduce costs.

[0047] In a specific example, the movable detector (the first detector 130a in this embodiment) can move axially within the scanning field of view of the CT imaging device. (See key reference) Figure 1 and Figure 3As shown, the first detector 130a can move along the Z-direction to block or expose the second detector 130b. Typically, the first detector 130a, the second detector 130b, and the imaging radiation source 110 are all mounted on a frame 300. This frame 300 has a large space along the axial direction of the scanning field of view, thus facilitating the movement of the first detector 130a along the axial direction of the scanning field of view. Furthermore, since the second detector 130b has a smaller size along the Z-direction, moving the first detector 130a to expose the second detector can shorten the movement distance, save space, and ensure the stability of the mechanical structure.

[0048] Continue to refer to Figure 1 and Figure 3 As shown, the gantry 300 is used to support the imaging radiation source 110, the collimator 120, and the first detector 130a and the second detector 130b. The gantry 300 also has a cavity for accommodating the irradiated object, with the imaging radiation source 110 and the detectors positioned on opposite sides of the cavity. During scanning, the irradiated object is placed within the cavity of the gantry 300, and the gantry 300 rotates the imaging radiation source 110, the collimator 120, and the first detector 130a and the second detector 130b in a certain direction and at a certain speed, so that the X-rays generated by the imaging radiation source 110, after passing through the collimator 120, are emitted as a cone-shaped or fan-shaped beam and then received by the first detector 130a or the second detector 130b after passing through the irradiated object.

[0049] It should be noted that, in this embodiment, the first detector 130a and the second detector 130b are arranged radially along the scanning field of view, and the detector arranged on the inner side (i.e., the first detector 130a) can move relative to the detector arranged on the outer side (i.e., the second detector 130b) along the axial direction of the scanning field of view to block or expose the detector arranged on the outer side. However, in other examples, the detector arranged on the inner side can also rotate about the axis of the scanning field of view to block or expose the detector arranged on the outer side (i.e., the first detector can rotate about the Z-axis relative to the second detector to block or expose the second detector).

[0050] In another alternative embodiment, the first and second detectors can be arranged circumferentially around the axis of the scanning field of view. In this case, both the first and second detectors can be configured to rotate and move around the Z-axis, so that the first and second detectors alternately move to positions opposite to the imaging radiation source 110.

[0051] In the CT imaging device provided in this embodiment, by setting an adjustable collimator 120 and matching it with a first detector 130a and a second detector 130b under different imaging modes, it is possible to perform fan-beam scanning imaging and cone-beam scanning imaging respectively with the first detector 130a and the second detector 130b under the same imaging radiation source 110. This allows the CT imaging device to integrate fan-beam imaging and cone-beam imaging functions, which greatly saves system space and also saves system costs.

[0052] Based on the CT imaging device described above, this embodiment also provides a radiotherapy device, which integrates the CT imaging device described above, and further includes a therapeutic radiation source for emitting a therapeutic beam (i.e., a therapeutic beam). The following is in conjunction with... Figures 5-7 The radiotherapy equipment in this embodiment will be described, wherein... Figure 5 This is a front view of the CT imaging device of a radiotherapy device according to one embodiment of the present invention in cone-beam imaging mode. Figure 6 This is a front view of the CT imaging device of a radiotherapy device in fan-beam imaging mode according to one embodiment of the present invention. Figure 7 In another embodiment of the present invention, the first detector in the CT imaging device of a radiotherapy device can be used for the main view of the treatment beam detector.

[0053] Combination Figures 5-7 As shown, in the radiotherapy device, its therapeutic radiation source 210 is used to emit a therapeutic beam (e.g., a therapeutic X-ray beam) that will irradiate the treatment area to perform radiotherapy (RT).

[0054] Furthermore, the radiotherapy equipment includes a CT imaging device for acquiring CT images of the imaging area. Specifically, the imaging radiation source 110 in the CT imaging device emits an imaging beam (e.g., an imaging X-ray beam). The emitted imaging beam is adjusted into a cone or fan beam after passing through the collimator 120 and irradiates the imaging area. After passing through the imaging area, the cone or fan beam is received by a first detector 130a or a second detector 130b for further generation of CT images related to the imaging area.

[0055] Specifically, the radiotherapy equipment in this embodiment can monitor the treatment area using a CT imaging device before and / or during radiotherapy, so as to adjust the treatment position and treatment conditions according to the changes in the target area of ​​the treatment area, thereby realizing image-guided radiotherapy (IGRT).

[0056] In this embodiment, the imaging area of ​​the CT imaging device and the treatment area of ​​the radiotherapy at least partially overlap. Specifically, the range of the imaging area of ​​the CT imaging device can be greater than or equal to the range of the treatment area of ​​the radiotherapy to ensure that image data within the treatment area can be acquired. That is, the path of the cone-beam imaging mode (or the path of the fan-shaped X-ray beam in the fan-beam imaging mode) of the CT imaging device intersects with the path of the treatment beam, resulting in an overlap in their irradiation ranges. In this embodiment, the paths of the cone-beam and fan-shaped X-ray beams are orthogonal to the path of the treatment beam.

[0057] In one embodiment, the center position of the imaging area of ​​the CT imaging device coincides with the center position of the treatment area of ​​the radiotherapy device. That is, the center position of the imaging area along the axial direction (Z-axis) of its scanning field of view coincides with the center position of the treatment area in the corresponding direction (Z-axis). In this case, the accelerators in the imaging system and the radiotherapy system can be arranged coplanarly (for example, the accelerators in the imaging system and the radiotherapy system can be arranged on the same rotating ring) so that the center positions of the imaging area and the treatment area coincide. It should be noted that the "center position coincidence" described here is not limited to the case of zero center offset. When the two center positions are slightly offset within a predetermined range, it still falls within the scope of "center position coincidence".

[0058] Furthermore, the energy level of the imaging beam generated by the imaging reflector 110 in the CT imaging apparatus may be the same as or different from the energy level of the treatment beam generated by the treatment radiation source 210. For example, the X-ray beam generated by the imaging radiation source 110 may have a kilovolt (kV) energy level, while the X-ray beam generated by the treatment radiation source 210 may have a megavolt (MV) energy level.

[0059] Furthermore, the radiotherapy device also includes a treatment beam detector 220 for receiving the treatment beam. In a specific embodiment, the treatment beam detector 220 may be, for example, an area array detector (or a flat panel detector).

[0060] In one alternative approach, the key reference is... Figure 5 and Figure 6 As shown, the treatment beam detector 220 is positioned opposite the treatment radiation source 210 and is used only to receive treatment beams associated with the treatment radiation source 210.

[0061] During radiotherapy, the treatment area can be treated with a therapeutic radiation source 210, and the treatment beam detector 220 receives the treatment beam to detect or monitor its status (e.g., radiation dose) based on the received beam. Furthermore, image data of the imaging area (including the treatment area) can be acquired using a CT imaging device to obtain a CT image of the imaging area. It should be understood that the CT imaging device can switch between cone-beam imaging mode and fan-beam imaging mode, thus allowing adjustment of its imaging mode as needed to obtain image data in the corresponding mode. For example… Figure 5 The diagram above exemplarily illustrates the structure of a CT imaging device in cone-beam imaging mode. Figure 6 The diagram above provides an example of a CT imaging device in fan-beam imaging mode. The specific adjustment method of the imaging mode of the CT imaging device can be referred to the above embodiment, and will not be repeated here.

[0062] That is, in Figure 5 and Figure 6 In the radiotherapy equipment shown, a set of detectors (i.e., first detector 130a and second detector 130b) is provided for the imaging radiation source 110 of the CT imaging device; and a set of detectors (i.e., treatment radiation source 210) is also provided for the treatment radiation source 210 used for radiotherapy. The imaging system and the radiotherapy system in the radiotherapy equipment are relatively independent. In this case, the imaging system can be set coplanarly with the accelerator in the radiotherapy system, or it can be set separately.

[0063] In another alternative solution, the key reference is... Figure 7 As shown, the first detector 130a in the CT imaging device can also be used as a treatment beam detector; that is, the first detector 130a used for cone-beam imaging is also used for data acquisition of the treatment beam. Specifically, the first detector 130a is movable, allowing it to move between a position opposite to the imaging radiation source 110 and a position opposite to the treatment radiation source 210. Figure 7 In the radiotherapy equipment shown, the imaging system can usually be set coplanarly with the accelerator in the radiotherapy system.

[0064] As described above, the energy level of the imaging beam generated by the imaging reflection source 110 can be the same as or different from the energy level of the treatment beam generated by the treatment radiation source 210. When the energy levels of the imaging beam and the treatment beam are the same, the first detector 130a can be directly used for acquiring both the imaging beam and the treatment beam; when the energy levels of the imaging beam and the treatment beam are different, the first detector 130a can be adjusted to enable it to acquire beams of different energy levels. For example, a dual-layer detector can be used to construct the first detector 130a to meet the acquisition requirements of beams of different energy levels.

[0065] Continue to refer to Figures 5-7 As shown, the radiotherapy equipment also includes a gantry 300. The CT imaging device (including an imaging radiation source 110, a collimator 120, a first detector 130a, and a second detector 130b), the therapeutic radiation source 210, and the therapeutic beam detector 220 can all be mounted on the gantry 300. The gantry 300 can drive the imaging radiation source 110, the collimator 120, the first detector 130a, the second detector 130b, the therapeutic radiation source 210, and the therapeutic beam detector 220 to rotate in a predetermined direction and at a predetermined speed.

[0066] As described above, the imaging system and the accelerator in the radiotherapy system can be arranged in the same plane. For example, the imaging system and the accelerator in the radiotherapy system can be arranged on the same rotating ring. Alternatively, the imaging system and the accelerator in the radiotherapy system can be arranged in a different plane. For example, the imaging system and the accelerator in the radiotherapy system can be arranged on different rotating rings so that they can rotate independently of each other.

[0067] In summary, the CT imaging device provided in this embodiment has a collimator with an adjustable aperture size, which allows the imaging beam generated under the same imaging radiation source to switch between a fan-shaped beam and a cone-shaped beam. It is equipped with a first detector for receiving the cone-shaped beam for cone-shaped beam data acquisition and a second detector for receiving the fan-shaped beam for fan-shaped beam data acquisition. This enables the switching between cone-beam imaging mode and fan-beam imaging mode when sharing the same imaging radiation source, so that the same CT imaging device integrates both cone-beam imaging and fan-beam imaging functions.

[0068] Furthermore, by integrating the CT imaging device provided in this embodiment into the radiotherapy equipment, the radiotherapy equipment can adjust its CT imaging mode according to the needs when performing image-guided radiotherapy, thereby improving the flexibility of the equipment.

[0069] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Regarding the methods disclosed in the embodiments, since they correspond to the devices disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section description.

[0070] While the present invention has been disclosed above with reference to preferred embodiments, these embodiments are not intended to limit the invention. For any person skilled in the art, many possible variations and modifications can be made to the technical solutions of the present invention based on the disclosed technical content, or equivalent embodiments can be modified accordingly, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, shall still fall within the protection scope of the present invention.

[0071] Furthermore, it should be recognized that the terminology described herein is used only to describe particular embodiments and not to limit the scope of the invention. It must be noted that the singular forms “a” and “an” used herein and in the appended claims include plural bases unless the context clearly indicates otherwise. For example, a reference to “a step” or “an apparatus” means a reference to one or more steps or apparatuses, and may include secondary steps and secondary apparatuses. All conjunctions used should be understood in the broadest sense. And the word “or” should be understood to have the definition of logical “or” rather than logical “exclusive OR”, unless the context clearly indicates otherwise.

Claims

1. A CT imaging device, characterized in that, include: An imaging radiation source for generating an X-ray beam for imaging; and capable of reducing the generated X-rays when the CT imaging device performs fan-beam imaging, and capable of generating more X-rays when the CT imaging device performs cone-beam imaging. A collimator, located on the beam-out side of the imaging radiation source and having an adjustable-sized opening, is used to limit the switching of the emitted X-ray beam between a cone beam and a fan beam; In cone-beam imaging mode, the collimator has a larger opening along the axial direction of the scanning field of view; in fan-beam imaging mode, the collimator has a smaller opening along the axial direction of the scanning field of view; and, A first detector and a second detector, the first detector being used to receive the X-rays of the cone beam at the moment the cone beam is generated, and the second detector being used to receive the X-rays of the fan beam at the moment the fan beam is generated.

2. The CT imaging device as described in claim 1, characterized in that, The first detector and the second detector are arranged along the X-ray beam path, and at least the detector arranged in front is movable, and the detector arranged in front can move back and forth to block or expose the detector arranged behind.

3. The CT imaging apparatus as described in claim 2, characterized in that, The first detector is positioned in front of the second detector and is movable.

4. The CT imaging apparatus as described in claim 2, characterized in that, The detectors arranged in front are movable at least along the axis of the scanning field of view of the CT imaging device.

5. The CT imaging apparatus as described in claim 1, characterized in that, The aperture size of the collimator is adjustable at least along the axial direction of the scanning field of view of the CT imaging device to switch between cone beam and fan beam.

6. The CT imaging apparatus as described in claim 1, characterized in that, The first detector is an area array detector, and the second detector is a linear array detector.

7. A radiotherapy device, characterized in that, The device includes a CT imaging apparatus as described in any one of claims 1-6; and the radiotherapy apparatus further includes a therapeutic radiation source for emitting a therapeutic beam.

8. The radiotherapy device as described in claim 7, characterized in that, The radiotherapy device also includes a treatment beam detector, which is disposed opposite to the treatment radiation source for receiving the treatment beam.

9. The radiotherapy device as described in claim 7, characterized in that, The first detector in the CT imaging device is movable and can move between a position opposite to the imaging radiation source and a position opposite to the treatment radiation source, for receiving a cone beam of X-rays when facing the imaging radiation source and for receiving a treatment beam when facing the treatment radiation source.

10. The radiotherapy device as described in claim 7, characterized in that, The center of the imaging area of ​​the CT imaging device coincides with the center of the treatment area of ​​the radiotherapy device.

Images