CN116350249A - CT imaging device and radiotherapy equipment - Google Patents

Abstract

The invention provides a CT imaging device and radiation therapy equipment. In the CT imaging device, the size of the opening of the collimator is adjusted so that the emitted X-ray beam can be switched between the cone beam and the fan beam, and the first detector is used for data acquisition when the cone beam is generated, and the second detector is used for data acquisition when the fan beam is generated. Therefore, under the condition of sharing the same imaging radiation source, the mutual switching between the cone beam imaging mode and the fan beam imaging mode is realized, so that the same CT imaging device is integrated with the cone beam imaging function and the fan beam imaging function at the same time, the occupied space of equipment can be saved, the system cost is greatly reduced, and the use flexibility under different CT imaging modes is improved.

Description

CT imaging device and radiotherapy equipment

Technical Field

The invention relates to the technical field of medical imaging, in particular to a CT imaging device and radiation therapy equipment.

Background

Today's radiation therapy plays an increasingly important role in tumor therapy, and in order to irradiate tumor sites more precisely and protect critical organs around tumors better, various imaging means are applied in the field of image-guided radiotherapy (IGRT), such as kilovoltage cone beam CT (kV-CBCT) and kilovoltage fan beam CT (kV-FBCT), etc.

Cone Beam CT (CBCT) is specifically a three-dimensional image obtained by acquiring projection data by rotating a sphere tube and an area array detector around an irradiated body in a single revolution, and reconstructing the acquired image data. Fan-beam CT (FBCT) is a method of acquiring image data by using a linear array detector, and reconstructing the acquired image data to obtain a two-dimensional image, which requires stacking a plurality of consecutive two-dimensional slices to form a three-dimensional image. That is, CBCT has a large scanning range, which can realize rapid three-dimensional imaging, but its image noise is also large so that the image quality is relatively low; and FBCT has a smaller scan range, however it can achieve better two-dimensional imaging quality.

It can be seen that CBCT and FBCT have different advantages, respectively, and in practical application, different modes can be selected for scanning according to the requirements. In the prior art, CBCT and FBCT are difficult to integrate in the same machine, and different imaging systems are usually arranged in different devices respectively, which not only occupies a large space, but also greatly increases the system cost because corresponding components are required to be independently configured for each set of imaging system.

Disclosure of Invention

The invention aims to provide a CT imaging device which solves the problem that the existing CT imaging device is difficult to integrate a cone beam imaging mode and a fan beam imaging mode into the same machine.

In order to solve the above 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-exiting side of the imaging radiation source and having an adjustable-size opening for restricting the emitted X-ray beam from switching between a cone beam and a fan beam; and a first detector for receiving the X-rays of the cone beam at the time of generating the cone beam, and a second detector for receiving the X-rays of the fan beam at the time of generating the fan beam.

Optionally, the first detector and the second detector are arranged along a beam path direction of the X-ray, and at least the front arranged detector is movably arranged, and the front arranged detector can move back and forth to shield or expose the rear arranged detector.

Optionally, the first detector is arranged before the second detector and is movably arranged.

Optionally, the front arranged detector is movable at least in an axial direction of a scan field of view of the CT imaging device.

Optionally, the size of the opening of the collimator is adjustable at least in the axial direction of the scanning field of view of the CT imaging apparatus for switching between cone-beam and fan-beam.

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

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

Optionally, the radiotherapy apparatus further comprises a treatment beam detector disposed opposite the treatment radiation source for receiving a treatment beam.

Optionally, a first detector in the CT imaging apparatus is movably arranged and movable between a position opposite the imaging radiation source and a position opposite the treatment radiation source for receiving the cone beam of X-rays when facing the imaging radiation source and for receiving the treatment beam when facing the treatment radiation source.

Optionally, a central position of an imaging region of the CT imaging apparatus coincides with a central position of a treatment region of the radiotherapy apparatus.

In the CT imaging device provided by the invention, the collimator with the adjustable opening size is arranged, so that the emitted X-ray beam can be switched between the cone beam and the fan beam by adjusting the opening size of the collimator under the condition of sharing the same imaging radiation source, and the first detector for receiving the cone beam and the second detector for receiving the fan beam are matched. Therefore, under the condition of sharing the same imaging radiation source, the mutual switching between the cone beam imaging mode and the fan beam imaging mode is realized, so that the same CT imaging device is integrated with the cone beam imaging function and the fan beam imaging function at the same time, the occupied space of equipment can be saved, the system cost is greatly reduced, and the use flexibility under different CT imaging modes is improved.

Drawings

Fig. 1 is a front view of a CT imaging apparatus in a cone-beam imaging mode in accordance with an embodiment of the present invention.

Fig. 2 is a cross-sectional view of the CT imaging apparatus shown in fig. 1 along the XZ plane in a cone-beam imaging mode.

Fig. 3 is a front view of a CT imaging apparatus in a fan beam imaging mode according to an embodiment of the present invention.

Fig. 4 is a cross-sectional view of the CT imaging apparatus shown in fig. 3 along the XZ plane in a fan beam imaging mode.

Fig. 5 is a front view of a CT imaging apparatus of one of the radiation therapy devices in a cone-beam imaging mode according to an embodiment of the present invention.

Fig. 6 is a front view of a CT imaging apparatus of one of the radiation therapy devices according to an embodiment of the present invention in a fan-beam imaging mode.

Fig. 7 is a front view of another radiation therapy device in accordance with an embodiment of the present invention, in which a first detector in a CT imaging apparatus can be shared with a treatment beam detector.

Wherein, the reference numerals are as follows:

110-an imaging reflection source;

a 120-collimator;

130 a-a first detector;

130 b-a second detector;

210-a therapeutic reflection source;

220-a treatment beam detector;

300-frame.

Detailed Description

As described in the background art, the fan-beam CT and the cone-beam CT in the prior art are disposed in different devices, which not only occupies a large space, but also has high cost, and the fan-beam CT scan imaging and the cone-beam CT scan imaging are required to be performed in different devices, respectively, so that the application is complicated.

To this end, the present invention provides a CT imaging apparatus that integrates both cone beam imaging and fan beam imaging functions. Specifically, the present invention provides a CT imaging apparatus comprising: an imaging radiation source for generating an imaging X-ray beam; a collimator with an adjustable opening size; and a first detector for receiving the cone beam at the time of generating the cone beam, and a second detector for receiving the fan beam at the time of generating the fan beam.

That is, in the CT imaging apparatus provided by the present invention, the collimator thereof has an opening whose size is adjustable, so that it is possible to switch the emitted X-ray beam between the cone beam and the fan beam by adjusting the opening size of the collimator while sharing the same imaging radiation source; and a first detector (e.g., an area array detector) may be used to receive the cone beam X-rays when emitting the cone beam, and a second detector (e.g., a line array detector) may be used to receive the fan beam X-rays when emitting the fan beam. Thus, the switching of different imaging modes can be realized by using the same imaging radiation source in the same equipment.

The CT imaging apparatus and the radiotherapy apparatus according to the present invention will be described in further detail with reference to FIGS. 1 to 4 and the embodiment. FIG. 1 is a front view of a CT imaging apparatus in a cone-beam imaging mode according to an embodiment of the present invention; FIG. 2 is a cross-sectional view of the CT imaging device shown in FIG. 1 along the XZ plane in a cone-beam imaging mode; FIG. 3 is a front view of a CT imaging device in fan-beam imaging mode in accordance with an embodiment of the present invention; fig. 4 is a cross-sectional view of the CT imaging apparatus shown in fig. 3 along the XZ plane in a fan beam imaging mode. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the invention. And relative terms such as "above," "below," "top," "bottom," "over" and "under" as illustrated in the accompanying drawings may be used to describe various elements' relationship to one another. These relative terms are intended to encompass different orientations of the element in addition to the orientation depicted in the figures. For example, if the device is inverted relative to the view in the drawings, an element described as "above" another element, for example, will now be below the element.

As shown in fig. 1 to 4, the CT imaging apparatus includes: the radiation source 110, the collimator 120, and the first detector 130a and the second detector 130b are imaged.

Wherein the imaging radiation source 110 is used for generating X-rays for imaging. In a specific example, the imaging radiation source 110 may be a CT bulb including a cathode end having an electron generating source for generating electrons and an anode end that emits electrons to bombard an anode target in the anode end to radiate X-rays. Wherein the electron generating source in the cathode terminal may be a hot cathode, such as a filament (specifically, a tungsten filament or a molybdenum filament, etc.); the electron generating source may also be a cold cathode for field effect emission of electrons, such as carbon nanotubes or silicon nanoneedles, etc. And, the anode target in the anode end may include an element of high atomic number, such as tungsten or molybdenum, etc.

Further, the CT bulb is also connected to a high voltage generator (not shown) for providing a high voltage to the cathode or anode end of the CT bulb. In this embodiment, the electrical signal provided to the CT bulb may be adjusted for the specific imaging mode performed by the CT imaging apparatus. For example, when fan-beam imaging is performed for a CT imaging apparatus, the voltage supplied to the CT bulb may be reduced to reduce the discharge power, thereby reducing the generated X-rays; however, when the cone beam imaging is performed for the CT imaging device, the voltage provided to the CT bulb tube can be increased to increase the discharge power, so that more X-rays can be generated, and the requirement of the cone beam imaging is met.

Referring with great reference to fig. 2 and 4, the collimator 120 is located on the beam-exiting side of the imaging radiation source 110 and has an adjustable-size opening for restricting the switching of the emitted X-ray beam between cone and fan beams. That is, when it is desired to switch the cone-shaped X-ray beam to a fan-shaped X-ray beam, then the size of the opening of the collimator 120 can be adjusted (e.g., the size of the opening is reduced in a predetermined direction) such that the emitted X-ray beam is a fan-shaped X-ray beam; alternatively, when it is desired to switch the fan-shaped X-ray beam to a cone-shaped X-ray beam, the size of the opening of the collimator 120 can be adjusted (e.g., the size of the opening is increased in a predetermined direction) so that the emitted X-ray beam is a cone-shaped X-ray beam.

In this embodiment, the scanning range of the cone-shaped X-ray beam is extended to a larger range (i.e., the scanning range of the cone-shaped X-ray beam has a larger area in the Z direction with respect to the scanning range of the fan-shaped X-ray beam) at least in the axial direction of the scanning field of the CT imaging apparatus with respect to the scanning range of the fan-shaped X-ray beam, and therefore, the size of the opening of the collimator 120 can be adjusted at least in the axial direction of the scanning field of the CT imaging apparatus. Specifically, in the cone-beam imaging mode, the collimator 120 may be configured to have a larger opening in the Z direction to confine the cone-beam; and, in the fan beam imaging mode, the collimator 120 may be arranged with a smaller opening in the Z direction to confine the fan X-ray beam.

With continued reference to fig. 1-4, the first detector 130a is configured to receive the cone beam of X-rays at the time the cone beam is generated. That is, in the cone-beam imaging mode, the first detector 130a will be positioned opposite the imaging radiation source 110 and exposed to the scan range in the cone-beam imaging mode to receive the cone-beam X-rays. And, the second detector 130b is for receiving the X-rays of the fan beam at the moment of generating the fan beam. That is, in the fan beam imaging mode, the second detector 130b will be positioned opposite the imaging radiation source 110 and exposed to the scan range in the fan beam imaging mode to receive the fan beam X-rays.

Alternatively, at least one of the first detector 130a and the second detector 130b may be movably disposed, so that the first detector 130a and the second detector 130b are alternately exposed in the scan field of view of the CT imaging apparatus.

For example, the first detector 130a and the second detector 130b are arranged along the direction of the beam path of the X-rays, at this time, at least the front arranged detector may be movably disposed, so that the front arranged detector may be reciprocally moved to block or expose the rear arranged detector, and when the front arranged detector blocks the rear arranged detector, the front arranged detector is activated for receiving the corresponding X-rays; conversely, when the rear arranged detector is exposed, the rear arranged detector is activated for receiving the corresponding X-rays. Wherein the front detector is the detector that is closer to the imaging radiation source 110. In addition, the detectors arranged at the back can be movably arranged or can be fixedly arranged, and the arrangement is not limited herein. For convenience of description, the movable detector is hereinafter defined as a movable detector, and in this embodiment, the first detector 130a is a movable detector.

In this embodiment, the first detector 130a is arranged before the second detector 130b and is movably disposed. Referring specifically to fig. 1 and 2, in a cone-beam imaging mode, the first detector 130a will be moved to a relative position to the imaging radiation source 110 (where the first detector 130a is correspondingly within the scanning range of the cone-beam) and the second detector 130b will be shielded. Referring next to fig. 3 and 4, in the fan-beam imaging mode, the first detector 130a is moved 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, and the second detector 130b is located within the scanning range of the fan-beam.

Further, the first detector 130a for receiving the cone beam X-rays in this embodiment is specifically an area array detector (or may be referred to as a flat panel detector), and the second detector 130b for receiving the fan beam X-rays is a line array detector. In this embodiment, the area array detector may be a flat panel detector. And the linear array detector is specifically an arc detector, so that X-rays can be received by the arc detector vertically or nearly vertically, and the imaging precision is improved.

As described above, the scanning range of the cone-shaped X-ray beam is extended to a larger range with respect to the scanning range of the fan-shaped X-ray beam at least in the axial direction of the scanning field of view, and thus the area of the area array detector has a larger area with respect to the linear array detector at least in the axial direction of the scanning field of view (as shown in fig. 2 and 4, the first detector 130a has a larger area in the Z-direction) so as to satisfy the scanning field of view of the cone-shaped X-ray beam. Based on this, in the present embodiment, by disposing the first detector 130a before the second detector 130b, the first detector 130a may be made closer to the imaging radiation source 110, so that the area of the first detector 130a may be reduced while satisfying the same scan field of view, which is advantageous for further cost reduction.

In a specific example, the movable detector (i.e., the first detector 130a in this embodiment) is specifically movable in the axial direction of the scanning field of view of the CT imaging apparatus. Referring specifically to fig. 1 and 3, the first detector 130a may be moved along the Z direction to block or expose the second detector 130b. Generally, the first detector 130a, the second detector 130b, and the imaging radiation source 110 are disposed on a gantry 300, and the gantry 300 has a large space in the axial direction of the scan field of view, so that the first detector 130a can easily move on the gantry 300 along the axial direction of the scan field of view. Also, since the second probe 130b has a small size in the Z direction, by moving the first probe 130a to expose the second probe, a moving distance can be shortened to save space and secure stability of a mechanical structure.

With continued reference to fig. 1 and 3, the gantry 300 is used to carry the imaging radiation source 110, the collimator 120, and the first and second detectors 130a, 130b. And, the gantry 300 also has a cavity for receiving the irradiated body, and the imaging radiation source 110 and the detector are disposed at opposite sides of the cavity. During the scanning process, the irradiated body is placed in the cavity of the gantry 300, and the gantry 300 drives the imaging radiation source 110, the collimator 120, the first detector 130a and the second detector 130b to rotate according to a certain direction and a certain speed, so that the X-rays generated by the imaging radiation source 110 are received by the first detector 130a or the second detector 130b after the cone beam or the fan beam emitted by the collimator 120 passes through the irradiated body.

It should be noted that, in the present embodiment, the first detector 130a and the second detector 130b are arranged along the radial direction of the scan field of view, and the inner-arranged detector (i.e., the first detector 130 a) may relatively move along the axial direction of the scan field of view to shield or expose the outer-arranged detector (i.e., the second detector 130 b). However, in other examples, the detectors arranged on the inner side may also be moved rotationally about the axis of the scan field of view, for example, to block or expose the detectors arranged on the outer side (i.e., the first detector may be moved rotationally about the Z-axis relative to the second detector to block or expose the second detector).

Furthermore, in another alternative, the first detector and the second detector may also be circumferentially arranged around the axis of the scan field of view. At this time, the first detector and the second detector may each be rotatably movable about the Z axis such that the first detector and the second detector alternately move to positions opposite the imaging radiation source 110.

In the CT imaging apparatus provided in this embodiment, by setting the collimator 120 with an adjustable opening and matching the first detector 130a and the second detector 130b in different imaging modes, it is realized that the fan-beam scanning imaging and the cone-beam scanning imaging are correspondingly performed under the same imaging radiation source 110 with the first detector 130 and the second detector 130b, so that the CT imaging apparatus integrates the fan-beam imaging function and the cone-beam imaging function, which greatly saves the system space and also saves the system cost.

Based on the CT imaging apparatus as described above, there is also provided in the present embodiment a radiation therapy apparatus having the CT imaging apparatus as described above integrated therein, and a therapeutic radiation source for emitting a therapeutic harness (i.e., a therapeutic beam) is also provided in the radiation therapy apparatus. The radiation therapy device of the present embodiment will be described with reference to fig. 5 to 7, wherein fig. 5 is a front view of a CT imaging apparatus of one of the radiation therapy devices of an embodiment of the present invention in a cone-beam imaging mode; FIG. 6 is a front view of a CT imaging device of one of the radiation therapy devices in a fan-beam imaging mode, in accordance with one embodiment of the present invention; fig. 7 is a front view of another radiation therapy device in accordance with an embodiment of the present invention, in which a first detector in a CT imaging apparatus can be shared with a treatment beam detector.

As shown in connection with fig. 5-7, in the radiation therapy apparatus, a therapeutic radiation source 210 is configured to emit a therapeutic beam (e.g., a therapeutic X-ray beam) that is to be irradiated to a treatment region for Radiation Therapy (RT).

And, in the radiotherapy apparatus, a CT imaging device thereof is used for capturing CT images of an imaging region. Specifically, the imaging radiation source 110 in the CT imaging apparatus is configured to emit an imaging beam (for example, an X-ray beam for imaging), and the emitted imaging beam is adjusted to a cone beam or a fan beam after passing through the collimator 120 and irradiates an imaging region, and the cone beam or the fan beam is received by the first detector 130a or the second detector 130b after passing through the imaging region, so as to further generate a CT image related to the imaging region.

Specifically, the radiotherapy apparatus in this embodiment may monitor at least the treatment region with the CT imaging device before and/or during the radiotherapy, so as to correspondingly adjust the treatment position, the treatment condition, and the like according to the target area change of the treatment region, thereby implementing Image Guided Radiotherapy (IGRT).

Wherein the imaging region of the CT imaging device and the treatment region of the radiation therapy at least partially overlap. Specifically, the range of the imaging region of the CT imaging apparatus may be equal to or greater than the range of the treatment region of the radiation treatment to ensure that image data within the treatment region can be acquired. That is, the CT imaging apparatus intersects the path of its cone-shaped X-ray beam (or the path of its fan-shaped X-ray beam in the fan-shaped beam imaging mode) and the path of the therapeutic beam in the cone-shaped beam imaging mode such that the irradiation ranges of both have overlap, in this embodiment, the cone-shaped X-ray beam and the path of the fan-shaped X-ray beam are orthogonal to the path of the therapeutic beam.

In an embodiment, the central position of the imaging region of the CT imaging apparatus coincides with the central position of the treatment region of the radiotherapy device. That is, the center position of the imaging region in the axial direction (Z axis) of the scanning field thereof coincides with the center position of the treatment region in the corresponding direction (Z axis). At this time, the accelerators in the imaging system and the radiation therapy system may be arranged coplanar (e.g., the accelerators in the imaging system and the radiation therapy system may be arranged on the same rotating ring) so that the center position of the imaging region and the center position of the treatment region coincide. It should be noted that, the "center position coincidence" described herein is not limited to the case of the center zero shift, and still falls within the scope of the "center position coincidence" when the two center positions slightly shift within the predetermined range.

In addition, the energy level of the imaging beam generated by imaging reflection source 110 in a CT imaging device may be the same as or different from the energy level of the therapeutic beam generated by therapeutic radiation source 210. For example, the X-ray beam generated by imaging radiation source 110 may have kilovoltage (kV) energy levels, and the X-ray beam generated by therapeutic radiation source 210 may have Megavoltage (MV) energy levels.

Further, the radiotherapy apparatus further comprises a treatment beam detector 220, the treatment beam detector 220 being adapted to receive a treatment beam. In a specific embodiment, the treatment beam detector 220 may be, for example, an area array detector (or a flat panel detector).

In an alternative, and with particular reference to fig. 5 and 6, the treatment beam detector 220 is positioned opposite the treatment radiation source 210 and is configured to receive only the treatment beam associated with the treatment radiation source 210.

Wherein during an operation of performing radiation treatment, a treatment region may be irradiated with a treatment radiation source 210 and a treatment beam received by the treatment beam detector 220 to detect or monitor a condition (e.g., radiation dose, etc.) of the treatment beam based on the received beam. And, image data of the imaging region (including the treatment region) may be acquired with a CT imaging device to obtain a CT image of the imaging region. It should be appreciated that the CT imaging apparatus is capable of switching between a cone beam imaging mode and a fan beam imaging mode, and thus can adjust its imaging mode as desired and obtain image data in the corresponding mode. For example, fig. 5 is an exemplary schematic diagram showing a structure of a CT imaging apparatus in a cone beam imaging mode, fig. 6 is an exemplary schematic diagram showing a structure of a CT imaging apparatus in a fan beam imaging mode, and a specific adjustment manner of the imaging mode of the CT imaging apparatus may refer to the foregoing embodiments, which are not described herein.

That is, in the radiotherapy apparatus shown in fig. 5 and 6, a set of detectors (i.e., a first detector 130a and a second detector 130 b) are provided corresponding to the imaging radiation source 110 of the CT imaging apparatus; and, a set of detectors (i.e., therapeutic radiation source 210) is also provided for therapeutic radiation source 210 for radiation therapy. The imaging system and the radiation therapy system in the radiation therapy device are relatively independent, in which case the imaging system may or may not be disposed coplanar with the accelerator in the radiation therapy system.

In another alternative, referring to fig. 7 with emphasis, the first detector 130a in the CT imaging apparatus may be shared with the treatment beam detector, i.e. the first detector 130a for cone-beam imaging is also used for data acquisition of the treatment beam. In particular, the first detector 130a is movably disposed such that the first detector 130a is movable between a position opposite the imaging radiation source 110 and a position opposite the treatment radiation source 210. In the radiation therapy device shown in fig. 7, the imaging system can be generally co-planar with an accelerator in the radiation therapy system.

As described above, the imaging beam produced by the imaging reflection source 110 may have the same or different energy levels as the therapeutic beam produced by the therapeutic radiation source 210. In the case where the energy level of the imaging beam and the energy level of the therapeutic beam are the same, then the first detector 130a may be directly adapted for acquisition of the imaging beam and the therapeutic beam; in the case that the energy levels of the imaging beam and the therapeutic beam are different, the first detector 130a may be adjusted to have the collection performance of the beams with different energy levels, for example, a dual-layer detector may be used to form the first detector 130a so as to meet the collection of the beams with different energy levels.

With continued reference to fig. 5-7, the radiation therapy apparatus further includes a gantry 300, the CT imaging modality (including the imaging radiation source 110, the collimator 120, and the first and second detectors 130a, 130 b), the therapeutic radiation source 210, and the therapeutic beam detector 220 may all be disposed on the gantry 300, and the gantry 300 may rotate 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 in a predetermined direction and at a predetermined speed.

As described above, the imaging system may be arranged coplanar with the accelerator in the radiation therapy system, in which case the accelerator in the imaging system and the radiation therapy system may be arranged on the same rotating ring, for example; alternatively, the imaging system may be positioned non-coplanar with the accelerator in the radiation therapy system, in which case, for example, the accelerators in the imaging system and the radiation therapy system may be positioned on separate rotating rings to rotate independently of each other.

In summary, in the CT imaging apparatus provided in this embodiment, the collimator with an adjustable opening size is provided, so that the imaging beam generated under the same imaging radiation source can be switched between the fan beam and the cone beam, and the first detector for receiving the cone beam is matched with the second detector for receiving the fan beam to perform data acquisition of the cone beam, so that the mutual switching between the cone beam imaging mode and the fan beam imaging mode under the condition of sharing the same imaging radiation source is realized, and the same CT imaging apparatus is integrated with both the cone beam imaging function and the fan beam imaging function.

Furthermore, when the CT imaging apparatus provided in this embodiment is integrated in a radiotherapy apparatus, the radiotherapy apparatus may be enabled to correspondingly adjust a CT imaging mode of the radiotherapy apparatus according to a requirement when performing image-guided radiotherapy, thereby improving flexibility of use of the apparatus.

The embodiments in this specification are described in a progressive manner, and identical and similar parts between the embodiments are all mutually referred to. For the method disclosed in the embodiment, the description is relatively simple because of corresponding to the device disclosed in the embodiment, and the relevant points are referred to in the description of the method section.

While the invention has been described in terms of preferred embodiments, the above embodiments are not intended to limit the invention. Many possible variations and modifications of the disclosed technology can be made by anyone skilled in the art without departing from the scope of the technology, or the technology can be modified to be equivalent. Therefore, any simple modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention still fall within the scope of the technical solution of the present invention.

It should also be understood that the terminology described herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. It must be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to "a step" or "an apparatus" means a reference to one or more steps or apparatuses, and may include sub-steps as well as sub-apparatuses. All conjunctions used should be understood in the broadest sense. And, the word "or" should be understood as having the definition of a logical "or" rather than a logical "exclusive or" unless the context clearly indicates the contrary.

Claims (10)

1. A CT imaging apparatus, comprising:

an imaging radiation source for generating an imaging X-ray beam;

a collimator located on the beam-exiting side of the imaging radiation source and having an adjustable-size opening for restricting the emitted X-ray beam from switching between a cone beam and a fan beam; the method comprises the steps of,

a first detector for receiving the X-rays of the cone beam at the moment of generating the cone beam and a second detector for receiving the X-rays of the fan beam at the moment of generating the fan beam.

2. The CT imaging modality of claim 1, wherein the first detector and the second detector are arranged along a beam path of X-rays and at least a front arranged detector is movably disposed, the front arranged detector being reciprocally movable to block or expose the rear arranged detector.

3. The CT imaging modality of claim 2, wherein the first detector is arranged before the second detector and is movably disposed.

4. The CT imaging modality of claim 2, wherein the front disposed detector is movable in at least an axial direction of a scan field of view of the CT imaging modality.

5. The CT imaging modality of claim 1, wherein the collimator has an opening size that is adjustable at least in an axial direction of a scan field of view of the CT imaging modality to effect switching between cone beam and fan beam.

6. The CT imaging modality of claim 1, wherein the first detector is an area array detector and the second detector is a linear array detector.

7. A radiation therapy device comprising a CT imaging apparatus according to any one of claims 1 to 6; and, the radiotherapy apparatus further comprises a therapeutic radiation source for emitting a therapeutic beam.

8. The radiation therapy device defined in claim 7, further comprising a therapeutic beam detector disposed opposite the therapeutic radiation source for receiving a therapeutic beam.

9. The radiation therapy device defined in claim 7, wherein the first detector in the CT imaging apparatus is movably disposed and movable between a position opposite the imaging radiation source and a position opposite the treatment radiation source for receiving X-rays of the cone beam when facing the imaging radiation source and receiving the treatment beam when facing the treatment radiation source.

10. The radiation therapy device defined in claim 7, wherein a center position of an imaging region of said CT imaging apparatus coincides with a center position of a treatment region of said radiation therapy device.

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