Patent Application
20250107761
The present application claims priority from Japanese Patent Application JP 2023-171891 filed on Oct. 3, 2023, the content of which is hereby incorporated by reference into this application.
The present invention relates to an X-ray detector mounted on an X-ray computed tomography (CT) apparatus.
The X-ray CT apparatus is an apparatus that generates a tomographic image of a subject by using a plurality of projection data obtained by detecting X-rays transmitted through the subject from various directions. The tomographic image generated by the X-ray CT apparatus is used as a medical image for diagnosing the subject. In the X-ray CT apparatus, an X-ray detector is multi-sliced in a body axis direction of the subject to enable wide-range imaging in a short time.
US2016/0170038A discloses that, in order for the X-ray detector to be multi-sliced in the body axis direction of the subject, components in which a collimator that removes scattered rays and a tiling module that converts X-rays into an electric signal are in one-to-one correspondence are arranged in the body axis direction of the subject.
However, in US2016/0170038A, sufficient consideration is not given to manufacturing man-hours in a case where the X-ray detector is further multi-sliced. In a case where the components in which the collimator and the tiling module are in one-to-one correspondence are arranged in the body axis direction of the subject, it is necessary to align the number of collimators corresponding to the number of tiling modules, which increases the manufacturing man-hours.
An object of the present invention is to provide an X-ray CT apparatus capable of reducing manufacturing man-hours of an X-ray detector that is multi-sliced in a body axis direction of a subject.
In order to achieve the above object, according to an aspect of the present invention, there is provided an X-ray CT apparatus comprising: an X-ray source that irradiates a subject with X-rays; an X-ray detector that detects the X-rays transmitted through the subject; a signal processing unit that obtains a plurality of projection data based on an electric signal output from the X-ray detector; and an image generation unit that generates a tomographic image by using the projection data, in which the X-ray detector includes a plurality of detector modules that are arranged in a channel direction, the detector module includes sub-detector modules that are arranged in a body axis direction of the subject, and the sub-detector module is configured such that a plurality of tiling modules that convert the X-rays into an electric signal are associated with one collimator that removes scattered rays.
According to the present invention, it is possible to provide an X-ray CT apparatus capable of reducing manufacturing man-hours of an X-ray detector that is multi-sliced in a body axis direction of a subject.
Hereinafter, examples of an X-ray CT apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the following description and the accompanying drawings, components having the same functional configuration will be denoted by the same reference numerals, and duplicated descriptions will not be repeated.
An overall configuration of an X-ray CT apparatus will be described with reference to
The X-ray source 100 is a device that irradiates a subject 104 with X-rays and is, for example, an X-ray tube device. The X-rays applied from the X-ray source 100 are radially emitted from a focus of the X-ray source 100.
The X-ray detector 101 is a device detecting the X-rays transmitted through the subject 104, converts the X-rays into an electric signal, and transmits the electric signal to the signal processing unit 110. The X-ray detector 101 comprises a plurality of detector modules 102 that are arranged in a channel direction. A configuration of the detector module 102 will be described below with reference to
The rotation plate 103 is a device that mounts the X-ray source 100 and the X-ray detector 101 and rotates. The X-rays that transmit through the subject are detected from various directions by the rotation of the rotation plate 103.
The table 105 is a device on which the subject 104 is placed and moves the subject 104 in the body axis direction or a direction orthogonal to a body axis of the subject 104.
The signal processing unit 110 is a device that controls each unit and receives the electric signal transmitted from the X-ray detector 101, and is, for example, a micro-processing unit (MPU). The signal processing unit 110 obtains a plurality of projection data based on the received electric signal and transmits the obtained projection data to the image generation unit 111.
The image generation unit 111 is a device that generates a tomographic image using the plurality of projection data transmitted from the signal processing unit 110, and is, for example, a graphics processing unit (GPU). The tomographic image generated by the image generation unit 111 is displayed on a display device such as a liquid crystal display and is used as a medical image for diagnosing the subject 104.
The detector module 102 will be described with reference to
The plurality of sub-detector modules 202 are arranged along the body axis direction of the subject 104 and are fixed on the support block 201. In addition, it is preferable that the sub-detector modules 202 are disposed such that their upper surfaces face the focus of the X-ray source 100. A configuration of the sub-detector module 202 will be described below with reference to
The support block 201 is a member that supports the plurality of sub-detector modules 202. The sub-detector module 202 is fixed by a screw 203 as shown in
The sub-detector module 202 will be described with reference to
The tiling module 302 includes a scintillator 304, a photodiode 305, and an AD conversion unit 306. The scintillator 304 is a member converting X-rays into visible light and emits an amount of visible light corresponding to an amount of incident X-rays. The photodiode 305 is an element converting visible light into an electric signal and transmits an electric signal corresponding to an amount of incident visible light to the AD conversion unit 306. The electric signal that is transmitted to the AD conversion unit 306 is an analog signal. A plurality of detection elements are formed on an XZ plane of the scintillator 304 and the photodiode 305, and the analog signal is output for each detection element. The AD conversion unit 306 converts the analog signal transmitted from the photodiode 305 into a digital signal. In a case of converting the analog signal into the digital signal, since the AD conversion unit 306 generates heat, the sub-detector module 202, which includes the tiling module 302 having the AD conversion unit 306, serves as a heat source.
The substrate 303 is a member that supports the plurality of tiling modules 302. In order to dissipate the heat generated by the AD conversion unit 306 of the tiling module 302, a material having a relatively large thermal conductivity, for example, aluminum, is used for the substrate 303. In addition, for example, a thickness of the adhesive layer applied between the substrate 303 and the tiling module 302 may be adjusted such that X-ray incidence surfaces of the tiling modules 302 are flush with each other. The adhesive layer having a relatively large thermal conductivity is used.
The collimator 301 is a member removing scattered rays generated by the subject 104 or the like, includes a grid or a slit formed of a material having a relatively large atomic number, for example, tungsten, and is disposed on the X-ray source 100 side with respect to the tiling module 302. The grid made of tungsten may be formed using a three-dimensional printer. The collimator 301 is mounted on the plurality of tiling modules 302 such that a line connecting each of a plurality of detection elements provided in the tiling module 302 and the focus of the X-ray source 100 passes through a hole of the grid or a gap of the slit, and is fixed by an adhesive.
As illustrated in
A connection between the sub-detector module 202 and the control board 401 will be described with reference to
The control board 401 is fixed to a board attachment part 403 using a screw 404 or a stud 501. In addition, the board attachment part 403 may have a hole 503 for allowing the flexible cable 402 to pass through. As illustrated in
In addition, in order to protect the control board 401 from X-rays, a shielding part 405 may be provided on the board attachment part 403. The shielding part 405 is made of a material having a relatively large atomic number, for example, lead, and is disposed to hide the control board 401 from the focus of the X-ray source 100. The disposition of the shielding part 405 is not limited to the example of
The examples of the present invention have been described above. The present invention is not limited to the above examples, and the components can be modified and embodied without departing from the spirit of the invention. In addition, a plurality of the components disclosed in the above examples may be combined as appropriate. Further, some components may be deleted from all the components shown in the above examples.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-171891 | Oct 2023 | JP | national |
