JP2007125231A - X-ray ct apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray CT apparatus which can easily and surely transmit high-speed data from a rotating body side to a mount side for achieving high-quality and speedy generation of a tomographic image. <P>SOLUTION: The X-ray CT apparatus has: the rotating body 11 of a cylindrical shape with an opening in a first direction and with a bottom 111 formed in a second direction opposite to the first direction; and the mount 12 housing the rotating body 11 rotatably with the center of the axis of the cylindrical shape as the center of rotation. A communication means 24 for communicating between the side of the rotating body 11 and the side of the mount 12 is provided in the vicinity of the center of the rotation of the rotating body 11 at each of the bottom 111 of the rotating body 11 and the side wall part 121 of the mount 12 opposing the rotating body 11. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an X-ray CT apparatus, and more particularly to an X-ray CT diagnostic apparatus that performs high-speed data communication between a rotating body side and a fixed body (mounting base) side.

  An optical transmission device that transmits data as a light beam propagating in space between a rotating body and a stationary body can rotate 180 ° without being restricted by the use of a cable, and can slip. Since a mechanical contact portion is not required unlike a transmission device using a ring, there is an advantage of high reliability.

  Such an optical transmission device between a rotating body and a fixed body is used in, for example, an X-ray CT (Computed Tomography) apparatus which is one of medical image diagnostic apparatuses. That is, the X-ray CT apparatus has a rotating body and a fixed body, both of which have a cavity, and a subject (human body) can enter the cavity. The rotator is provided with an X-ray tube and an X-ray detector. When the rotator is rotated, X-rays are irradiated from the X-ray tube toward the subject, for example, scanning is performed in a spiral shape. . X-rays that have passed through the subject are detected by an X-ray detector and taken out as an electrical signal. After this signal is digitized, it is converted into a light beam by a light emitting element and transmitted to the stationary body. The light beam transmitted to the fixed body side is received by the light receiving element, and the digital data obtained as an electrical signal is subjected to image processing, whereby tomographic image information of the subject is acquired.

  Specifically, each component used in the optical transmission device between the rotating body and the fixed body will be described. As the light emitting element, a light emitting diode (LED) or a laser diode (LD) can be used, for example, a large size exceeding 100 Mbps. When carrying out capacity / high-speed transmission, an LD is usually used in many cases. A photodiode (PD) is generally used as the light receiving element.

  3 to 5 are diagrams showing a conventional configuration of an X-ray CT apparatus. As shown in FIG. 3, an X-ray irradiator 21 and an X-ray detector 22 are mounted on the same rotator 11 inside the gantry of the conventional X-ray CT apparatus 1.

  Then, the rotating body 11 rotates around the subject P placed on the bed 14 with the body axis direction as the center, and the X-ray detector 22 collects projection data at each angle, which is collected by the computer. A tomogram can be obtained by reconstructing with. Since the X-ray detector 22 is in the rotating body 11, as shown in FIG. 4, the X-ray detector 22 is provided in a portion that is not rotated from the communication means 24 a provided in the rotating body 11 (hereinafter referred to as a fixed body 13). It is necessary to send the collected projection data to the communication means 24b.

  FIG. 4 is a block diagram showing a specific conventional configuration of the X-ray CT apparatus. As shown in FIG. 4, the conventional X-ray CT apparatus 1 includes an X-ray irradiation unit 21 such as an X-ray tube that irradiates a subject P placed on a bed 14 with an X-ray, and an X-ray irradiation. A body axis direction of the subject P placed on the bed 14, which is disposed opposite to the unit 21 and incorporates an X-ray detection unit 22 that detects X-rays from the X-ray irradiation unit 21 through the subject P. And a rotator 11 having an X-ray irradiator 21 and an X-ray detector 22 configured in an annular shape so that the rotator 11 is rotatable, and a gantry 12 that accommodates the rotator 11 and rotatably supports it. .

(Information communication system)
In addition, as the “information communication system”, the rotating body 11 includes a data collection unit 23 that collects projection data obtained by the X-ray detection unit 22, and a communication unit that transmits projection data collected by the data collection unit 23. On the other hand, the gantry 12 (fixed body 13) is provided with a communication unit 24b for receiving projection data transmitted from the communication unit 24a.

  Here, the structure of the rotary body 11 and the fixed body 13 is demonstrated with reference to drawings. FIG. 5 is a front view and a side view showing a conventional configuration of the rotating body 11 and the fixed body 13 installed in the X-ray CT apparatus. As shown in FIG. 5, the rotating body 11 according to the present embodiment is fixed to a gantry (mounting base) 12 and has an annular shape that is slightly smaller than the fixing body 13 that forms an annular shape. Opposing to each other with a predetermined gap.

  A laser diode (LD) is provided as a communication means (light emitting element) 24 a for transmitting projection data received from a built-in data collection unit 23 (not shown) on the surface of the rotating body 11 facing the fixed body 13. A plurality of annular elements are arranged on the outer edge side of the surface, and a photodiode (PD) as a communication unit (light receiving element) 24b for receiving projection data received from the communication unit 24a is provided on the surface of the fixed body 13 facing the rotating body 11. ) Is installed on the in-plane edge side.

(Image processing system)
The gantry 12 has an “image processing system” as an “image processing system”, an image processing unit 31 that performs image processing of projection data received via the communication unit 24 b, a rotation driving unit 32 that rotates the rotating body 11, and X-ray irradiation. A scan control unit 33 that performs scan control on the unit 21 and controls the rotation drive unit 32, an overall control unit 34 that controls the image processing unit 31 and the scan control unit 33, and an image obtained by the overall control unit 34 A display unit 35 for displaying a medical image processed by the processing unit 31 and a power supply unit 36 for supplying power to the overall control unit 34 are provided.

JP-A-7-283789

  In recent years, X-ray CT apparatuses have evolved to the point that cardiac imaging can be targeted as a new imaging region. However, in the above-mentioned form, when a moving part such as the heart is photographed and an attempt is made to realize high-quality and speedy tomographic image generation, it is clear that there will be limitations due to the following reasons. It was.

In order to obtain a moving part like a heart as a high-quality tomographic image, there are the following points.
(1) Multi-row: In order to collect projection data of the entire heart at once, it is desirable that the X-ray detector be multi-row.
(2) High resolution: The more projection data is collected at a fine pitch (X-ray detector width and rotation angle increment), the more detailed projection information can be obtained.
(3) High-speed rotation: Since it is desired to collect projection data at the moment when the heart is not moving, it is desirable that the rotating body rotate at a speed that allows one rotation at the moment when the heart is not moving, and high-speed rotation is required.

  Therefore, in order to obtain a moving part like a heart as a high-quality tomographic image, the projection data collected when the above (1) and (2) are realized becomes a larger amount of data than before. On the other hand, in order to reduce the inspection time, if a large amount of projection data is not stored in the rotator 11 and is quickly transferred to the fixed body 13, the amount of data transfer required per single time (= transmission speed) Becomes larger (faster).

  In order to realize high-quality and speedy tomographic image generation by cardiac imaging, it is indispensable to realize high-speed data transmission from the rotating body 11 to the fixed body 13. In the structure of the conventional X-ray CT apparatus provided with the communication means 24 at the peripheral portion of 12 (fixed body 13), since the hole is opened at the center of the gantry 12, the rotating body 11 and the fixed body 13 are necessarily formed. The communication area performed between the rotating body 11 and the stationary body 13 is limited to the opposing surfaces of the rotating body 11 and the fixed body 13.

  That is, in the conventional communication structure, there is a problem that a stable signal is received at any rotational position, and it is difficult to suppress variation at each angle, the amount of data to be transmitted becomes large, or the rotation of the rotating body 11 The higher the speed, the more high-speed communication must be realized, and a technique for ensuring the image quality is required.

  The present invention has been made in view of the above problems, and its purpose is to perform high-speed data transmission from the rotating body side to the fixed body (mounting base) side in order to realize high-quality and speedy image generation. An object of the present invention is to provide an X-ray CT apparatus which can be easily and reliably performed.

  The X-ray CT apparatus according to the first aspect of the present invention for solving the above-described problem is a cylindrical shape in which a first direction is opened and a bottom is formed in a second direction opposite to the first direction. Communication means for performing communication between the rotating body side and the gantry side, and a gantry that rotatably accommodates the rotator with the cylindrical shaft center as a center of rotation. The rotating body is provided in the vicinity of the center of rotation of the rotating body at each of the bottom of the rotating body and the side wall of the gantry facing the rotating body.

  In this way, by adopting a structure in which communication performed between the rotating body and the gantry is performed in the vicinity of the rotation center, the communication synchronization technology does not depend on the rotation speed and the like between the rotating body side and the fixed body side. Even if a technology capable of high-speed data transmission from a rotating body to a stationary body to realize high-quality and speedy tomographic image generation is developed in the future, a structure that can respond to it will be realized. An X-ray CT apparatus provided can be provided.

  An X-ray CT apparatus according to a second aspect of the present invention for solving the above-described problem has a cylindrical outer shape, and includes a rotating body having an X-ray irradiation unit and an X-ray detection unit therein, An X-ray CT apparatus having an opening for accommodating the rotating body in a direction and supporting the rotating body so as to be rotatable about the first direction as an axis. At the bottom center of the surface in the first direction and at the center of rotation of the surface in the second direction opposite to the first direction of the side wall of the gantry facing the rotating body. Communication means for sending an electrical signal output from the X-ray detection unit to the gantry side is provided at a corresponding position.

  An X-ray CT apparatus according to a third aspect of the present invention for solving the above problem is the X-ray CT apparatus according to the first or second aspect, wherein the communication means is disposed at the rotation center position. A light source that converts the electrical signal output from the X-ray detection unit into light and outputs the light, and a light receiver that is disposed at the rotation center position of the side wall and receives the light from the light source and outputs the electrical signal It is characterized by comprising.

  According to the present invention, since data transmission / reception performed between the rotating body and the fixed body (mounting base) is performed near the rotation center of the rotating body, it depends on the rotation speed of the rotating body and the data transfer speed. Even if a technology that can transmit data at high speed from a rotating body to a fixed body to realize high-quality and speedy tomographic image generation can be developed in the future, it is possible to respond to it. An X-ray CT apparatus having a structure can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description will be given only when necessary.

  FIG. 1 is an exploded perspective view showing a configuration in an embodiment of an X-ray CT apparatus according to the present invention. As shown in FIG. 1, an X-ray irradiation unit 21 and an X-ray detection unit 22 are mounted on the same rotating body 11 inside the gantry of the X-ray CT apparatus 1 of the present embodiment.

  Then, the rotating body 11 rotates around the subject P placed on the bed 14 around the body axis direction, and the X-ray detection unit 22 collects projection data at each angle, which is collected by the computer. A tomogram can be obtained by reconstructing with.

  The rotating body 11 has a cylindrical shape with an opening in the first direction and a bottom 111 formed in a second direction opposite to the first direction. The shape is accommodated in the second direction. That is, the gantry 12 is also open in the first direction. A disk-shaped fixed body 13 is installed on the side wall 121 of the gantry 12 so as to face the bottom 111 of the rotating body 11 and have a predetermined gap with respect to the rotating body 11. The rotating body 11 is supported by a bearing so as to be rotatable with respect to the fixed body 13.

  Therefore, since the X-ray detector 22 is in the rotating body 11, the communication means 24 a provided on the bottom 111 of the rotating body 11 is provided on the side wall 121 of the gantry 12 (the surface facing the fixed body 13 with respect to the rotating body 11). The collected projection data is sent to the communication means 24b.

  FIG. 2 is a cross-sectional view showing a configuration in an embodiment of the X-ray CT apparatus according to the present invention. As shown in FIG. 2, the X-ray CT apparatus 1 of the present embodiment includes an X-ray irradiation unit 21 such as an X-ray tube that irradiates a subject P placed on a bed 14 with X-rays, The body of the subject P placed on the bed 14, which is disposed opposite to the ray irradiation unit 21 and incorporates an X-ray detection unit 22 that detects X-rays from the X-ray irradiation unit 21 through the subject P. A rotating body 11 in which an X-ray irradiation unit 21 and an X-ray detection unit 22 are configured in an annular shape so as to be rotatable around an axial direction, the rotating body 11, and a fixed body 13 that rotatably supports the rotating body 11. And a gantry 12 in which is stored. In addition, the side wall part said to this claim points out the surface by the side of the 2nd direction which opposes the rotary body 11 in the mount frame 12, and in this embodiment, this fixed body 13 is between the mount frame 12 and the rotary body 11. Since it is interposed, the surface on the second direction side facing the rotating body 11 in the fixed portion 13 constitutes the side wall portion 121.

(Information communication system)
In addition, as the “information communication system”, the rotating body 11 includes a data collection unit 23 that collects projection data obtained by the X-ray detection unit 22, and a communication unit that transmits projection data collected by the data collection unit 23. 24a is provided, and in particular, the communication means 24a is disposed in the vicinity of the rotational center position by the support member 111a on the bottom 111 of the rotator 11 (the side facing the gantry 12 and the fixed body 13). In the present embodiment, the support member 111 a constitutes the bottom portion 111.

  On the other hand, the projection data transmitted from the communication means 24a is located at the rotation center position of the rotating body 11 on the surface of the fixing body 13 (side wall 121) facing the rotating body 11 of the fixed body 13 stored and installed on the gantry 12. Is provided.

  Specifically, communication for converting projection data (electrical signal) received from a built-in data collection unit 23 (not shown) into a light beam and transmitting the light beam on the surface of the rotating body 11 facing the fixed body 13. As the means 24 a, one (or a group) of laser diodes (LD) as light emitting elements are disposed in the vicinity of the rotation axis of the rotating body 11, and the communication means 24 a is disposed on the opposite surface 131 of the rotating body 11 in the fixed body 13. As a communication means 24b for converting the light beam received from the light into projection data of an electric signal, one (or one group) of photodiodes (PD) as light receiving elements are installed in the vicinity of the rotation axis of the rotating body 11 on the surface. Has been.

  As described above, in the rotating body 11 and the fixed body 13, the communication means 24 a and 24 b are disposed in the vicinity of the rotation axis of the rotating body 11, so that the projection data can be transferred from the rotating body 11 to the fixed body 13 at one point. It can be carried out. Since transmission can be performed at one point near the rotation center of the rotating body 11 and reception can be performed at one point near the position of the fixed body 13 facing the rotation center, special techniques are required to communicate in a ring shape as in the past. It is possible to easily adopt and implement a high-speed communication technology without any problems.

  Currently available communication technologies include charge coupled communication and radio wave communication in addition to the above laser communication. If femtosecond communication that will be realized in the future is put to practical use, terabit speed (Tbps) communication technology can be smoothly applied to an X-ray CT diagnostic apparatus.

  Each of the communication units 24a and 24b includes a laser diode and a photodiode, and the laser diode and the photodiode of the communication unit 24a are arranged at positions corresponding to the photodiode and the laser diode of the communication unit 24b. It is good as composition. In this case, mutual communication between the rotating body 11 side and the fixed body 13 (the gantry 12) side is possible, and the X-ray irradiation unit 21 and the X-ray detection unit 22 can be easily controlled from the fixed body 13 (the gantry 12) side. Become.

(Image processing system)
The gantry 12 has an “image processing system” as an “image processing system”, an image processing unit 31 that performs image processing of projection data received via the communication unit 24 b, a rotation driving unit 32 that rotates the rotating body 11, and X-ray irradiation. A scan control unit 33 that performs scan control on the unit 21 and controls the rotation drive unit 32, an overall control unit 34 that controls the image processing unit 31 and the scan control unit 33, and an image obtained by the overall control unit 34 A display unit 35 for displaying a medical image processed by the processing unit 31 and a power supply unit 36 for supplying power to the overall control unit 34 are provided.

  With the configuration described above, data transmission / reception performed between the rotating body and the fixed body (mounting base) is performed near the rotation center of the rotating body. In the future, even if a technology that can accurately transmit data without depending on speed and can transmit data at high speed from a rotating body to a stationary body to realize high-quality and speedy tomographic image generation will be developed. An X-ray CT apparatus having a structure capable of responding to the above can be provided.

  The X-ray CT apparatus according to the present invention does not target the whole body of the subject but exerts further effects by using the target focused on a part of the subject such as the heart. The reason why high-capacity communication and high-speed communication are required between the rotating body and the fixed body is that there is a background corresponding to cardiac imaging.

  Each above-mentioned embodiment is an example of the present invention, and the present invention is not limited to the above-mentioned embodiment. In addition, various modifications can be made according to the design and the like as long as they do not depart from the technical idea of the present invention.

1 is an exploded perspective view showing a configuration in an embodiment of an X-ray CT apparatus according to the present invention. The block diagram which shows the structure in one Embodiment of the X-ray CT apparatus which concerns on this invention. The disassembled perspective view which shows the conventional structure of a X-ray CT apparatus. The block diagram which shows the conventional structure of a X-ray CT apparatus. The figure which shows the structure of the rotary body and fixed body of the conventional X-ray CT apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 X-ray CT apparatus 11 Rotating body 111 Bottom part 12 Base 121 Side wall part 13 Fixed body 14 Bed 21 X-ray irradiation part 22 X-ray detection part 23 Data collection part 24 Communication means 31 Image processing part 32 Rotation drive part 33 Scan control part 34 General control unit 35 Display unit 36 Power supply unit P Subject

Claims (3)

A rotating body having a cylindrical shape in which a first direction is opened and a bottom is formed in a second direction opposite to the first direction;
A gantry that rotatably accommodates the rotating body with the cylindrical shaft center as a rotation center;
Communication means for performing communication between the rotating body side and the gantry side is provided in the vicinity of the rotation center of the rotating body at each of a bottom portion of the rotating body and a side wall portion of the gantry facing the rotating body. An X-ray CT apparatus characterized by that. A rotating body having a cylindrical outer shape and having an X-ray irradiation unit and an X-ray detection unit therein;
In an X-ray CT apparatus comprising: an opening for accommodating the rotating body in a first direction; and a gantry that rotatably supports the rotating body with the first direction as an axis.
The bottom of the rotating body facing the gantry, the position of the rotation center of the surface in the first direction,
The electrical signal output from the X-ray detection unit is placed at a position corresponding to the rotation center portion of the surface in the second direction opposite to the first direction of the side wall portion facing the rotating body in the gantry. An X-ray CT apparatus comprising a communication means for sending to the gantry side. The communication means includes a light source that converts an electrical signal output from the X-ray detection unit disposed at the rotation center position into light, and outputs the light.
The X-ray CT apparatus according to claim 1, further comprising: a light receiver that is disposed at the rotation center position of the side wall portion and outputs an electric signal in response to light from the light source.

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