X-ray CT device

Abstract

The present invention provides an X-ray CT apparatus capable of reducing the manufacturing man-hour of an X-ray detector in a plurality of rows in the body axis direction of a subject. This X-ray CT device is provided with: an X-ray source that irradiates a subject with X-rays; an X-ray detector that detects X-rays transmitted through the subject; a signal processing unit that obtains a plurality of projection data on the basis of an electric signal output from the X-ray detector; and an image generation unit that generates a tomographic image using the projection data, characterized in that the X-ray detector is provided with a plurality of detector modules arranged in the channel direction, the detector modules are provided with sub-detector modules arranged in the body axis direction of the subject, and the sub-detector modules are arranged in the channel direction. The sub-detector modules are configured in such a manner that a collimator for removing scattered rays is correspondingly associated with a plurality of tiling modules for converting X-rays into electric signals.

Description

Technical Field

[0001] The present invention relates to an X-ray detector mounted on an X-ray CT (Computed Tomography) device. Background Art

[0002] An X-ray CT apparatus is an apparatus that generates a tomographic image of a subject 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 diagnosis of the subject. In an X-ray CT apparatus, in order to be able to perform wide-range imaging in a short time, the X-ray detector is arranged in multiple rows in the body axis direction of the subject.

[0003] Patent document 1 discloses that in order to arrange X-ray detectors in multiple rows in the body axis direction of the subject, components consisting of a collimator for removing scattered rays and a tiling module for converting X-rays into electrical signals are arranged in a one-to-one correspondence along the body axis direction of the subject.

[0004] Patent Document 1: U.S. Patent Application Publication No. 2016 / 0170038

[0005] However, Patent Document 1 does not adequately consider the manufacturing time required when the X-ray detector is arranged in a larger number of rows. When assemblies in which collimators and tile modules are arranged in a one-to-one correspondence along the body axis of the subject, it is necessary to align the number of collimators corresponding to the number of tile modules, thereby increasing the manufacturing time. Summary of the invention

[0006] Therefore, an object of the present invention is to provide an X-ray CT apparatus capable of reducing the number of steps required to manufacture X-ray detectors that are arranged in multiple rows in the body axis direction of a subject.

[0007] In order to achieve the above-mentioned purpose, the present invention is an X-ray CT device, comprising: an X-ray source for irradiating an object with X-rays; an X-ray detector for detecting X-rays that pass through the object; a signal processing unit for obtaining a plurality of projection data based on an electrical signal output from the X-ray detector; and an image generating unit for generating a tomographic image using the projection data, characterized in that the X-ray detector comprises a plurality of detector modules arranged along a channel direction, the detector modules comprise sub-detector modules arranged along a body axis direction of the object, the sub-detector modules being configured such that a plurality of tiled modules for converting X-rays into electrical signals are associated with a collimator for removing scattered rays.

[0008] Effects of the Invention

[0009] According to the present invention, it is possible to provide an X-ray CT apparatus capable of reducing the number of steps required to manufacture X-ray detectors that are arranged in multiple rows in the body axis direction of a subject. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a diagram showing the overall structure of an X-ray CT apparatus.

[0011] Figure 2A It is a diagram showing an example of the structure of a detector module.

[0012] Figure 2B It is a diagram showing another example of the structure of the detector module.

[0013] Figure 3 It is a perspective view showing an example of the structure of a sub-detector module.

[0014] Figure 4 This is a diagram showing an example of connection between the sub-detector modules and the control substrate.

[0015] Figure 5 This is a diagram showing an example of connection between the sub-detector modules and the control substrate.

[0016] Explanation of symbols

[0017] 100-X-ray source, 101-X-ray detector, 102-detector module, 103-rotating plate, 104-subject, 105-workbench, 110-signal processing unit, 111-image generating unit, 201-support block, 202-sub-detector module, 203-screw, 204-adhesive, 301-collimator, 302-tiling module, 303-substrate, 304-scintillator, 305-photodiode, 306-AD conversion unit, 401-control substrate, 402-flexible cable, 403-substrate mounting portion, 404-screw, 405-shielding portion, 501-stud, 502-heat conducting portion, 503-hole, CN-connector. DETAILED DESCRIPTION

[0018] Hereinafter, an embodiment of the X-ray CT apparatus according to 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 are denoted by the same reference numerals to omit repeated description.

[0019] [Example 1]

[0020] use Figure 1 The overall structure of the X-ray CT apparatus is described below. The X-ray CT apparatus includes an X-ray source 100 , an X-ray detector 101 , a rotating plate 103 , a table 105 , a signal processing unit 110 , and an image generating unit 111 .

[0021] The X-ray source 100 is a device, such as an X-ray tube device, that irradiates X-rays to the subject 104. The X-rays irradiated from the X-ray source 100 are radially radiated from the focal point of the X-ray source 100.

[0022] The X-ray detector 101 is a device that detects X-rays that have passed through the subject 104, converts the X-rays into electrical signals, and transmits the electrical signals to the signal processing unit 110. The X-ray detector 101 includes a plurality of detector modules 102 arranged along the channel direction. The structure of the detector module 102 will be described later using FIG. 2. In the X-ray detector 101, the direction toward the focus of the X-ray source 100 is set as the Y direction, the body axis direction of the subject 104 is set as the Z direction, and the channel direction, which is a direction orthogonal to the Y direction and the Z direction, is set as the X direction.

[0023] The rotating plate 103 is a device that carries and rotates the X-ray source 100 and the X-ray detector 101. As the rotating plate 103 rotates, X-rays that have passed through the subject are detected from various directions.

[0024] The table 105 is a device for placing the subject 104 , and moves the subject 104 in the body axis direction of the subject 104 or in a direction perpendicular to the body axis.

[0025] The signal processing unit 110 is a device that controls each unit and receives an electrical signal sent from the X-ray detector 101 , such as an MPU (Micro-Processing Unit). The signal processing unit 110 obtains a plurality of projection data based on the received electrical signal and sends the obtained projection data to the image generating unit 111 .

[0026] The image generator 111 is a device, such as a GPU (Graphics Processing Unit), that generates a tomographic image using a plurality of projection data sent from the signal processor 110. The tomographic image generated by the image generator 111 is displayed on a display device such as a liquid crystal display as a medical image for diagnosis of the subject 104.

[0027] use Figure 2A and Figure 2B The detector module 102 will be described. The detector module 102 includes a plurality of sub-detector modules 202 and a support block 201 .

[0028] The plurality of sub-detector modules 202 are arranged along the body axis direction of the subject 104 and fixed to the support block 201. It is also preferred that the upper surfaces of the sub-detector modules 202 are arranged so as to face the focal point of the X-ray source 100. Figure 3This will be described later.

[0029] The support block 201 is a component that supports a plurality of sub-detector modules 202. Figure 2A The sub-detector module 202 is fixed by screws 203, or as Figure 2B In this way, the sub-detector module 202 is fixed by the adhesive 204. In addition, the screws 203 and the adhesive 204 may be used together. As described later, the sub-detector module 202 becomes a heat source, so a material with a relatively large thermal conductivity, such as aluminum, is used in the support block 201 to release the heat generated in the sub-detector module 202. In addition, the adhesive 204 is also preferably excellent in thermal conductivity.

[0030] use Figure 3 The sub-detector module 202 is described. The sub-detector module 202 includes a collimator 301 , a substrate 303 , and a plurality of tile modules 302 .

[0031] The tile module 302 has a scintillator 304, a photodiode 305, and an AD converter 306. The scintillator 304 is a component that converts X-rays into visible light, and emits an amount of visible light corresponding to the amount of incident X-rays. The photodiode 305 is an element that converts visible light into an electrical signal, and sends an electrical signal corresponding to the amount of incident visible light to the AD converter 306. The electrical signal sent to the AD converter 306 is an analog signal. In addition, a plurality of detection elements are formed on the XZ plane of the scintillator 304 and the photodiode 305, and an analog signal is output for each detection element. The AD converter 306 converts the analog signal sent from the photodiode 305 into a digital signal. When converting the analog signal into a digital signal, since the AD converter 306 generates heat, the sub-detector module 202 having the tile module 302 having the AD converter 306 becomes a heat source.

[0032] The substrate 303 is a component that supports the plurality of tile modules 302. A material with a relatively high thermal conductivity, such as aluminum, is used for the substrate 303 to release the heat generated by the AD converter 306 of the tile module 302. In addition, for example, the thickness of the adhesive layer applied between the substrate 303 and the tile module 302 may be adjusted so that the X-ray incident surfaces of the tile module 302 become the same plane. In addition, a material with a relatively high thermal conductivity is used for the adhesive layer.

[0033] The collimator 301 is a component that removes scattered rays generated in the subject 104, etc., and has a grid or slit formed of a material with a relatively large atomic number, such as tungsten, and is arranged on the side closer to the X-ray source 100 than the tiling module 302. The tungsten grid can be formed using a 3D printer. The collimator 301 is mounted on the plurality of tiling modules 302 and fixed by an adhesive in such a manner that a line connecting each of the plurality of detection elements of the tiling module 302 and the focus of the X-ray source 100 passes through the holes in the grid or the gaps in the slits. Figure 3 , the state before a collimator 301 is mounted on four tiling modules 302 is illustrated.

[0034] like Figure 3 As shown in the example, the sub-detector module 202 is configured such that a plurality of tiled modules 302 are associated with one collimator 301. With this structure, even when the X-ray detector is arranged in multiple rows, the number of collimators 301 that need to be aligned can be reduced, thereby reducing the manufacturing man-hours of the X-ray detector arranged in multiple rows in the body axis direction of the subject. Figure 3 As illustrated, the tiling modules 302 are not only arranged two-dimensionally along the body axis direction and the channel direction, but can also be arranged only along the body axis direction, or only along the channel direction.

[0035] use Figure 4 and Figure 5 , the connection between the sub-detector module 202 and the control substrate 401 is described. The control substrate 401 is a substrate for controlling the AD conversion unit 306 of the sub-detector module 202. The AD conversion unit 306 of the sub-detector module 202 is connected to a flexible cable 402, and the flexible cable 402 is connected to the connector CN of the control substrate 401.

[0036] The control substrate 401 is fixed to the substrate mounting portion 403 using screws 404 and studs 501. In addition, the substrate mounting portion 403 may have a hole 503 for passing the flexible cable 402. Figure 5 As shown in the example, the substrate mounting portion 403 has a T-shape on the XY plane, the support block 201 is arranged on the upper surface, and the control substrate 401 is fixed on the side. A material with a relatively large thermal conductivity, such as aluminum, is used in the substrate mounting portion 403 to release the heat transferred from the sub-detector module 202 via the support block 201. In addition, the control substrate 401 becomes a heat source when operating, so it is preferable to provide a heat conducting portion 502 between the control substrate 401 and the substrate mounting portion 403. In addition, the substrate mounting portion 403 is directly or indirectly connected to the rotating plate 103, and the heat transferred to the substrate mounting portion 403 is released to the rotating plate 103.

[0037] Furthermore, in order to protect the control substrate 401 from X-rays, a shielding portion 405 may be provided on the substrate mounting portion 403. The shielding portion 405 is made of a material with a relatively large atomic number, such as lead, and is configured to hide the control substrate 401 from the focal point of the X-ray source 100. In addition, the configuration of the shielding portion 405 is not limited to Figure 4 or Figure 5 For example, a shielding portion 405 may be disposed in the gap of the sub-detector module 202. By limiting the configuration of the shielding portion 405 to the gap of the sub-detector module 202, it is possible to protect the control board 401 from X-rays while ensuring the heat dissipation of the board mounting portion 403 and reducing the weight.

[0038] The embodiments of the present invention are described above. In addition, the present invention is not limited to the above embodiments, and the constituent elements can be modified and concretized within the scope of the main purpose of the invention. In addition, multiple constituent elements disclosed in the above embodiments can be appropriately combined. Furthermore, some constituent elements can also be deleted from all the constituent elements shown in the above embodiments.

Claims

1. An X-ray CT apparatus comprising: an X-ray source for irradiating an object with X-rays; an X-ray detector for detecting X-rays transmitted through the object; a signal processing unit for obtaining a plurality of projection data based on an electrical signal output from the X-ray detector; and an image generating unit for generating a tomographic image using the projection data, wherein: The X-ray detector comprises a plurality of detector modules arranged along the channel direction. The detector module includes sub-detector modules arranged along the body axis direction of the subject. The sub-detector module is configured such that a plurality of tile modules for converting X-rays into electrical signals are associated with one collimator for removing scattered rays.

2. The X-ray CT apparatus according to claim 1, characterized in that: The tiling module has an AD conversion unit that converts an analog signal into a digital signal. The X-ray CT device further includes a substrate supporting the plurality of tile modules, wherein the substrate is made of a material having a relatively high thermal conductivity.

3. The X-ray CT apparatus according to claim 2, characterized in that: It also includes: a control substrate for controlling the AD conversion unit; and a substrate mounting unit for fixing the control substrate. The substrate mounting portion is made of a material with a relatively large thermal conductivity.

4. The X-ray CT apparatus according to claim 3, characterized in that: The board mounting portion is provided with a shield portion that protects the control board from the X-rays.

5. The X-ray CT apparatus according to claim 4, characterized in that: The shielding portion is disposed in a gap between the sub-detector modules.

6. The X-ray CT apparatus according to claim 1, characterized in that: A supporting block for supporting the sub-detector module is also provided, and the supporting block is made of a material with a relatively large thermal conductivity.

7. The X-ray CT apparatus according to claim 1, characterized in that: The tiling modules are arranged along at least one direction of the channel direction and the body axis direction.

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