X-ray CT apparatus

Abstract

To provide an X-ray CT apparatus capable of reducing manufacturing man hours for X-ray detectors formed in multi-rows in a body axial direction of a subject.SOLUTION: An X-ray CT apparatus includes an X-ray source for irradiating a subject with an X-ray, an X-ray detector for detecting an X-ray transmitting the subject, a signal processing part for acquiring a plurality of pieces of projection data on the basis of the electric signal output from the X-ray detector, and an image generation part for generating a tomographic image using the projection data. The X-ray detector includes a plurality of detector modules arranged in a channel direction. The detector module includes a sub-detector module arranged in the body axial direction of the subject. The sub-detector module is configured so that a plurality of tiling modules for converting the X-ray into an electric signal is associated with one collimator for removing a scattered ray.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] X-ray CT scanners are devices that generate tomographic images of a subject using multiple projection data obtained by detecting X-rays that pass through the subject from various directions. The tomographic images generated by X-ray CT scanners are used as medical images for diagnosing the subject. X-ray CT scanners have multiple rows of X-ray detectors arranged in the direction of the subject's body axis to enable imaging of a wide range in a short time.

[0003] Patent Document 1 discloses that in order to arrange X-ray detectors in multiple rows in the direction of the subject's body axis, components that correspond one-to-one to a collimator that removes scattered radiation and a tiling module that converts X-rays into electrical signals are arranged in the direction of the subject's body axis. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2016 / 0170038 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in Patent Document 1, insufficient consideration is given to the number of manufacturing steps required when increasing the number of rows of the X-ray detector. When arranging components in which collimators and tiling modules correspond one-to-one to each other in the body axis direction of a subject, it becomes necessary to align the collimators in the number corresponding to the number of tiling modules, which increases the number of manufacturing steps.

[0006] SUMMARY OF THE PRESENTLY PREFERRED EMBODIMENT An object of the present invention is to provide an X-ray CT apparatus capable of reducing the number of steps required for manufacturing X-ray detectors arranged in multiple rows in the axial direction of a subject. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention provides an X-ray CT device comprising an X-ray source which irradiates an object with X-rays, an X-ray detector which detects X-rays passing through the object, a signal processing unit which obtains a plurality of projection data based on an electrical signal output from the X-ray detector, and an image generating unit which generates a tomographic image using the projection data, wherein the X-ray detector comprises a plurality of detector modules arranged in a channel direction, the detector module comprises sub-detector modules which are arranged in the body axis direction of the object, and the sub-detector module is configured such that a plurality of tiling modules which convert X-rays into electrical signals are associated with one collimator which removes scattered rays. Effect of the Invention

[0008] According to the present invention, it is possible to provide an X-ray CT apparatus capable of reducing the number of manufacturing steps for X-ray detectors arranged in multiple rows in the body axis direction of a subject. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing the overall configuration of an X-ray CT apparatus. [Figure 2A] FIG. 2 is a diagram illustrating an example of a configuration of a detector module. [Figure 2B] FIG. 13 is a diagram illustrating another example of the configuration of the detector module. [Diagram 3] FIG. 2 is a perspective view showing an example of a configuration of a sub-detector module. [Figure 4] 13 is a diagram showing an example of a connection between a sub-detector module and a control board. FIG. [Diagram 5] 13 is a diagram showing an example of a connection between a sub-detector module and a control board. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of an 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 designated by the same reference numerals, and duplicated explanations will be omitted. EXAMPLES

[0011] The overall configuration of the X-ray CT apparatus will be described with reference to Fig. 1. 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.

[0012] The X-ray source 100 is a device, such as an X-ray tube device, that irradiates X-rays onto the subject 104. The X-rays irradiated from the X-ray source 100 are emitted radially from the focal point of the X-ray source 100.

[0013] The X-ray detector 101 is a device that detects X-rays transmitted through a subject 104, converts the X-rays into an electric signal, and transmits the electric signal to a signal processing unit 110. The X-ray detector 101 includes a plurality of detector modules 102 arranged in a channel direction. The configuration of the detector modules 102 will be described later with reference to FIG. 2. In the X-ray detector 101, the direction toward the focus of the X-ray source 100 is defined as the Y direction, the direction of the body axis of the subject 104 is defined as the Z direction, and the channel direction that is perpendicular to the Y direction and the Z direction is defined as the X direction.

[0014] The rotating plate 103 is a device that rotates while mounting the X-ray source 100 and the X-ray detector 101. By the rotation of the rotating plate 103, X-rays that pass through the subject are detected from various directions.

[0015] The table 105 is a device on which the subject 104 is placed, and moves the subject 104 in the direction of the subject's 104 body axis or in a direction perpendicular to the body axis.

[0016] The signal processing unit 110 is a device, such as an MPU (Micro-Processing Unit), that controls each unit and receives an electrical signal transmitted from the X-ray detector 101. The signal processing unit 110 obtains a plurality of projection data based on the received electrical signal and transmits the obtained projection data to the image generating unit 111.

[0017] The image generating unit 111 is a device, such as a GPU (Graphics Processing Unit), that generates a tomographic image using a plurality of projection data transmitted from the signal processing unit 110. The tomographic image generated by the image generating 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.

[0018] 2A and 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.

[0019] The multiple sub-detector modules 202 are aligned along the body axis direction of the subject 104 and fixed on a support block 201. It is preferable that the sub-detector modules 202 are arranged such that the upper surfaces of the sub-detector modules 202 face the focal point of the X-ray source 100. The configuration of the sub-detector modules 202 will be described later with reference to FIG.

[0020] The support block 201 is a member that supports multiple sub-detector modules 202, and the sub-detector modules 202 are fixed by screws 203 as shown in Fig. 2A, or by adhesive 204 as shown in Fig. 2B. The screws 203 and adhesive 204 may be used together. As will be described later, the sub-detector modules 202 are a heat source, so that the support block 201 is made of a material with a relatively high thermal conductivity, such as aluminum, in order to dissipate heat generated by the sub-detector modules 202. It is also preferable that the adhesive 204 also has excellent thermal conductivity.

[0021] The sub-detector module 202 will be described with reference to Fig. 3. The sub-detector module 202 includes a collimator 301, a substrate 303, and a plurality of tiling modules 302.

[0022] The tiling module 302 has a scintillator 304, a photodiode 305, and an AD conversion unit 306. The scintillator 304 is a member 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 electric signal, and transmits an electric signal corresponding to the amount of incident visible light to the AD conversion unit 306. The electric signal transmitted to the AD conversion unit 306 is an analog signal. Note that 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 conversion unit 306 converts the analog signal transmitted from the photodiode 305 into a digital signal. When converting an analog signal into a digital signal, the AD conversion unit 306 generates heat, and therefore the sub-detector module 202 including the tiling module 302 having the AD conversion unit 306 becomes a heat source.

[0023] The substrate 303 is a member that supports the multiple tiling modules 302. A material with relatively high thermal conductivity, such as aluminum, is used for the substrate 303 so that heat generated by the AD conversion unit 306 of the tiling module 302 can be dissipated. Also, for example, the thickness of an adhesive layer applied between the substrate 303 and the tiling module 302 may be adjusted so that the X-ray incidence surfaces of the tiling modules 302 are flush with each other. Note that a material with relatively high thermal conductivity is used for the adhesive layer.

[0024] The collimator 301 is a member for removing scattered radiation generated by the subject 104, etc., and is a lattice or slit made of a material with a relatively large atomic number, such as tungsten, and is disposed closer to the X-ray source 100 than the tiling module 302. The tungsten lattice may be formed using a three-dimensional printer. The collimator 301 is mounted on a plurality of tiling modules 302 and fixed by adhesive so that lines connecting each of a plurality of detection elements of the tiling module 302 and the focal point of the X-ray source 100 pass through the holes or slits of the lattice. FIG. 3 illustrates a state before one collimator 301 is mounted on four tiling modules 302.

[0025] As illustrated in Fig. 3, the sub-detector module 202 is configured by associating a plurality of tiling modules 302 with one collimator 301. With such a configuration, even when the X-ray detector is configured with more rows, the number of collimators 301 that require alignment can be reduced, and the manufacturing man-hours for the X-ray detector with multiple rows in the body axis direction of the subject can be reduced. Note that the tiling modules 302 may not only be arranged two-dimensionally in the body axis direction and the channel direction as illustrated in Fig. 3, but may also be arranged only in the body axis direction or only in the channel direction.

[0026] 4 and 5, the connection between the sub-detector module 202 and the control board 401 will be described. The control board 401 is a board that controls the AD conversion units 306 of the sub-detector module 202. Flexible cables 402 are connected to each of the AD conversion units 306 of the sub-detector module 202, and each of the flexible cables 402 is connected to a connector CN of the control board 401.

[0027] The control board 401 is fixed to the board mounting part 403 using screws 404 or studs 501. The board mounting part 403 may have a hole 503 for passing the flexible cable 402. As illustrated in FIG. 5, the board mounting part 403 has a T-shape in the XY plane, the support block 201 is disposed on the upper surface, and the control board 401 is fixed to the side surface. The board mounting part 403 is made of a material with a relatively high thermal conductivity, such as aluminum, so as to dissipate heat transmitted from the sub-detector module 202 through the support block 201. Since the control board 401 becomes a heat source during operation, it is preferable to provide a heat conductive part 502 between the control board 401 and the board mounting part 403. The board mounting part 403 is directly or indirectly connected to the rotating plate 103, and heat transmitted to the board mounting part 403 is dissipated to the rotating plate 103.

[0028] Also, in order to protect the control board 401 from X-rays, a shielding portion 405 may be provided on the board mounting portion 403. The shielding portion 405 is made of a material with a relatively large atomic number, such as lead, and is arranged so as to hide the control board 401 from the focus of the X-ray source 100. The arrangement of the shielding portion 405 is not limited to the examples in Figs. 4 and 5, and the shielding portion 405 may be arranged, for example, in a gap between the sub-detector modules 202. By limiting the arrangement of the shielding portion 405 to the gap between the sub-detector modules 202, it is possible to ensure the heat dissipation property and reduce the weight of the board mounting portion 403 while protecting the control board 401 from X-rays.

[0029] The above describes the embodiments of the present invention. Note that the present invention is not limited to the above embodiments, and the components can be modified and embodied without departing from the scope of the invention. In addition, multiple components disclosed in the above embodiments may be appropriately combined. Furthermore, some components may be deleted from all the components shown in the above embodiments. [Explanation of symbols]

[0030] 100: X-ray source, 101: X-ray detector, 102: detector module, 103: rotating plate, 104: subject, 105: table, 110: signal processing unit, 111: image generation unit, 201: support block, 202: sub-detector module, 203: screw, 204: adhesive, 301: collimator, 302: tiling module, 303: board, 304: scintillator, 305: photodiode, 306: AD conversion unit, 401: control board, 402: flexible cable, 403: board mounting unit, 404: screw, 405: shielding unit, 501: stud, 502: heat conduction unit, 503: hole, CN: connector.

Claims

1. 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, The X-ray detector includes a plurality of detector modules arranged in a channel direction, the detector module includes sub-detector modules arranged in a body axis direction of the subject, The sub-detector module is an X-ray CT apparatus characterized in that a plurality of tiling modules that convert X-rays into electrical signals are associated with one collimator that removes scattered radiation.

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

3. 3. The X-ray CT apparatus according to claim 2, A control board for controlling the AD conversion unit and a board attachment part to which the control board is fixed, 2. An X-ray CT apparatus, wherein the substrate mounting portion is made of a material having a relatively high thermal conductivity.

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

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

6. 2. The X-ray CT apparatus according to claim 1, An X-ray CT apparatus further comprising a support block for supporting the sub-detector module, the support block being made of a material having a relatively high thermal conductivity.

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

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