JP2006075489A - X-ray ct apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray CT apparatus in which internal signal transmission has few noise, difficulty in mounting is improved, an occupied space is narrowed, signal deterioration is eliminated, and a production cost is reduced, and an X-ray CT apparatus of various numbers of slices, in which the degree of freedom in design corresponding to the form of circuit mounting is acquired. <P>SOLUTION: In the X-ray CT apparatus having an X-ray detector which detects X rays radiated from an X-ray tube, two or more data collection units which collect signals detected by the X-ray detector as an electric signal, a control section which collectively transmits data obtained by the data collection unit, a rotation section which carries and rotates these, a stationary section which supports the rotational movement, and an image processing section which carries out imaging of the data transmitted from the control section, an optical signal conversion section which is provided in each of data collection units and converts an output signal therefrom into an optical signal and an optical transmission section which carries out mutual daisy chain connection of the optical signal conversion sections are provided in the rotation section. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an X-ray projection data detection unit of an X-ray CT apparatus, and more particularly to a circuit configuration of a data acquisition system.

According to the prior art, the X-ray projection data detected by the detection element mounted on the rotating part of the X-ray CT apparatus is passed through a flexible substrate and a connector, an amplifier, an integrator, an analog-digital converter (ADC). To reach a data collection system.
Further, the data is digitized and then transmitted in parallel to the control unit, or serially transmitted to the control unit via parallel-serial conversion.
The data collected in the control unit on the rotating unit in this way is sent from the rotating unit to the fixed unit via a slip ring and a brush, and finally reaches the image processing apparatus on the fixed unit.

According to Patent Document 1, it is disclosed that optical communication is used in place of a slip ring and a brush as image data transmission between a rotating unit and a fixed unit of an X-ray CT apparatus. Optical communication is an advantageous transmission means in places where electrical wiring is difficult, such as between a rotating part and a fixed part. However, electrical wiring is used for transmission from the data collection system to the control unit on the rotating unit inside the rotating unit.
Japanese Patent Laid-Open No. 11-244276

  In recent years, multi-slicing has progressed in X-ray CT apparatuses, and the number of detection elements has greatly increased. Therefore, the amount of data transferred from the detection element substrate on which the detection elements are mounted is also increasing. For example, consider a case where detectors for 24 channels × 32 slices = 768 pixels are mounted on a single detection element substrate as a detector for 32 multi-slices. Usually, by arranging dozens of such detection element substrates and data acquisition substrates that amplify, integrate, and analog-to-digital conversion of the output from them, and connect them to each other, a large number of elements can be arranged in both the slice direction and the channel direction. Here, a case where 40 detection elements for 24 channels × 32 slices = 768 pixels are arranged is considered.

  The detection element substrate and the data collection substrate are usually connected in a one-to-one correspondence. In order to send and receive signals for the above 768 pixels, there are several mounting methods such as connecting with electric wires, flexible boards or connectors, or setting the detection element board and data collection board as one board from the beginning. There is.

  In arranging the detection substrates, the detection elements on the detection element substrate are arranged so as to form a predetermined curved surface that is almost equidistant from the X-ray tube. If the number of slices is less than 32 slices and the connection is made with an electric wire or flexible board, even if the data collection board is directly inserted into the connector on the flat motherboard, the electric wire and flexible board between the detection element board and the data collection board Due to flexibility, the detection element substrates can be arranged on the curved surface as described above. This motherboard has signal readout from the detection element, control of amplification, integration, and analog-digital conversion, and a relay point function for transmitting the digital signal after analog-digital conversion to the image processing unit. It is a control unit.

  However, for example, when the number of slices is 32 and the number of views is 24, the number of signal lines between the detection element substrate and the data collection substrate increases to 768. Accordingly, the wiring of the electric wire becomes complicated, and even if a flexible substrate is used, the wiring becomes thick and wide, and it becomes difficult to obtain flexibility that can be directly inserted into the mother board. As another aspect, as the number of slices or channels increases, the number of lines on the flexible substrate increases, the antenna effect of the flexible substrate increases, and noise may be easily picked up, which may affect image quality. Therefore, when the number of signal lines increases, it is conceivable to connect the detection element substrate and the data collection substrate with a connector instead of the flexible substrate.

  However, in this case, since the connection portion between the detection element substrate and the data collection substrate is a hard connector, flexibility cannot be obtained. Therefore, in order to connect a plurality of data collection boards on the motherboard by directly inserting the data collection board into the motherboard, it is necessary that the motherboard is curved like the detection board arrangement. . It is not preferred from the viewpoint of cost and manufacturing processing technology that the motherboard itself is curved. Alternatively, a flexible substrate or an electric wire can be used for connection from the data collection substrate to the mother board, but in this case, a great effort is required in connection with the antenna effect and connection. Thus, there are various restrictions on connecting the data collection board to the motherboard.

  Further, in the case of 32 multi-slices or more, it is conceivable that the detection element substrate and the data collection substrate are integrated. In this case, there is a difficulty in connecting to the mother board as well as the reason for connecting the detecting element substrate and the data collecting substrate with the connector.

  Next, a case where the signal reading method is changed will be described. Up to this point, the case where signals from the data collection board are transmitted in parallel has been described, but the case where signals are transmitted serially will be described. The detector elements for 24 channels x 32 slices = 768 pixels are mounted on a single detector element substrate, but the readout line as serial can be switched by switching the readout of signals in the channel direction or slice direction over time. For example, 32 for the number of slices or 24 for the channel. In this case, in the same manner as described above, several tens of data acquisition boards for amplifying, integrating, and analog-digital conversion of the detection element boards and outputs from the detection element boards can be connected to each other. Here, consider the case where 40 sheets are arranged. Since the number of connection lines between the detection element substrate and the data collection board is reduced to 32, it is possible to connect the data collection boards on the mother board by connecting with an electric wire or a printed board.

However, as described above, it is inevitable that noise is generated by the antenna effect of the flexible substrate and consequently affects the image quality. Furthermore, as the number of slices increases from 32 to 64, 128, and 256, the number of lines on the flexible board increases and the antenna effect becomes stronger, and the influence of noise is further increased. As the number of slices increases, the serial transfer rate becomes very high. When a high-frequency signal is transmitted by using parallel-serial conversion by switching or the like in the middle, the high-frequency signal transmitted in the conventional electric wire is easily attenuated, so that an accurate signal cannot be obtained.
In addition, the space occupied by the flexible board restricts the degree of freedom of mounting, and its product cost is high.

  The present invention is a signal between a detection element substrate, a data collection substrate, and a mother board that can be optimized collectively by taking into account various circumstances such as noise, mounting difficulties, space, signal attenuation, manufacturing cost, and design flexibility as described above. A transmission method is provided.

In order to achieve the above object, the present invention collects an X-ray tube for irradiating X-rays, an X-ray detector for detecting the irradiated X-rays, and signals detected by the X-ray detector as electrical signals. A plurality of data collection units that output this as optical signals, and at least the X-ray tube, the X-ray detector, and the data collection unit are mounted, and are covered between the X-ray tube and the X-ray detector. A rotating unit that sandwiches the sample and rotates around the sample, a fixed unit that supports the rotational movement of the rotating unit, a relay unit that relays signal transmission between the rotating unit and the fixed unit, and the fixed unit that is provided in the fixed unit An X-ray CT apparatus including an image processing unit that images a signal transmitted from a control unit includes an optical signal transmission unit that transmits a signal by connecting the output of the data collection unit to the relay unit.
The optical transmission unit may transmit a signal via at least one of an optical transmission line and air.

  Further, an X-ray tube for irradiating X-rays, an X-ray detector for detecting the irradiated X-rays, a plurality of data collection units for collecting signals detected by the X-ray detector as electrical signals, and the data A control unit that controls the collection unit and collectively transmits the data obtained by the data collection unit, the X-ray tube, the X-ray detector, the data collection unit, and the control unit, A subject is sandwiched between the X-ray tube and the X-ray detector, a rotating part that rotates around the subject, a fixed part that supports the rotational movement of the rotating part, and a transmission provided from the control part provided in the fixed part An X-ray CT apparatus comprising: an image processing unit configured to image the processed data; the rotation unit is provided for each data collection unit, and converts the output signal from the data collection unit into an optical signal. A signal conversion unit and an optical transmission unit for connecting the optical signal conversion units to each other are provided.

The rotation unit further includes a parallel-serial conversion unit that is connected between the plurality of data collection units and the optical signal conversion unit and performs parallel-serial conversion on signals from the plurality of data collection units. It is characterized by.
Each of the optical signal conversion units includes an input unit and an output unit, and an output unit of one optical signal conversion unit is connected to an input unit of another optical signal conversion unit by one of the optical transmission units. In addition, at least one input unit among all the optical signal conversion units is not connected to any other optical signal conversion unit.

The output of one of the optical signal converters is connected to the controller via one of the optical transmitters.
The optical transmission unit may be at least one of an optical transmission line and air.
In addition, a relay unit that performs signal transmission by a combination of a slip ring and a brush or optical transmission is provided between the rotating unit and the fixed unit.

  According to the X-ray CT apparatus according to the present invention, a detection element substrate and data that can be optimized together for various circumstances such as noise, mounting difficulties, space, signal attenuation, manufacturing cost, and design flexibility as described above. To provide a signal transmission method between the collection board and the motherboard, reduce noise, improve mounting difficulties, narrow the occupied space, eliminate signal degradation, reduce manufacturing cost, and various slice numbers and views Design flexibility can be obtained corresponding to various circuit implementations in several X-ray CT systems.

  Hereinafter, an embodiment of an X-ray CT apparatus according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is an overall configuration diagram showing an X-ray CT apparatus according to the present embodiment, an X-ray tube 3 for irradiating X-rays, a collimator 4 for limiting the X-ray irradiation range, and detecting X-rays as electrical signals. X-ray detector 2 for conversion, data collection unit 1 for collecting projection data from the X-ray detector 2, parallel-serial conversion unit 15 for converting parallel signals into serial signals, optical signal conversion for converting serial signals into optical signals Unit 16, collecting the converted optical signal and controlling the data collection unit 1 etc., X-ray tube 3, collimator 4, X-ray detector 2, data collection circuit 1, parallel-serial conversion unit 15, It is collected by the rotating unit 51 equipped with the optical signal conversion unit 16 and the control unit 17, the image processing unit 61 that performs image reconstruction using the signal (projection data) from the data acquisition circuit 1, and the control unit 17. Relay unit 19 that sends the received signal from the rotating disk side to the image processing unit 61 side, and image processing from the relay unit 19 Controls the transmission line 61 that is responsible for signal transmission to 61, the image display unit 62 that displays the results of image processing, the input device 52 that starts imaging and sets and inputs parameters, and the X-ray tube 3 and X-ray detector 2. A control device 53, a bed 54 that can be moved by mounting a subject, and the like.

  Next, a general operation of the X-ray CT apparatus will be described with reference to FIG. When the start of imaging is input from the input device 52, X-rays are emitted from the X-ray source 3 toward the subject 55 placed on the bed 54. The X-rays pass through the subject 55 and then enter the X-ray detector 2 as transmitted X-rays at step 501. In step 502, the incident X-rays are converted into light by an element called a scintillator, for example. In step 503, the optical signal is converted into an electric signal by an optical-electric conversion element such as a photodiode. In step 504, the converted electrical signal is amplified and integrated in the data acquisition circuit 1. In step 506, analog-digital conversion or the like is further performed to obtain projection data. Note that during normal imaging, the rotary disk 51 on which the X-ray tube 3 and the X-ray detector 2 are mounted rotates, and projection data is acquired from around the subject 55. In addition to the projection data, correction data for image correction is stored in the image processing unit 61 together with the projection data, and image correction processing and reconstruction calculation are also performed here. As a result, a tomographic image of the subject 55 is obtained and displayed on the image display unit 62.

  In this embodiment, after being converted into a digital signal in step 506, the parallel signal is converted into a serial signal in step 506, and the number of signal lines is reduced. In step 507, the serial signal is converted into an optical signal. In step 508, the optical signal thus obtained is sent to the relay unit 19. In step 509, a signal is transmitted from the rotating unit to the fixed unit via the relay unit 19. In step 510, the signal that has entered the fixed unit reaches the image processing unit 61 via the transmission path 63, and is used for subsequent image processing.

  Next, the configuration of the detection element and the data collection unit according to the present embodiment will be described in detail. On the X-ray detector 2, an element (such as the above scintillator) that converts X-rays into light is mounted on the X-ray incident side of the light detection element. When expressed as an X-ray detection element, an element that converts X-rays into light and a light detection element are combined. When the X-ray detector and the data collection unit are separate, as shown in Figs. 3 and 4, the output signal from the photodiode, which is a photodetection element, for example, is analog to the data collection unit via a flexible board or connector. It is transmitted in the signal state. This corresponds to the transmission between steps 503 and 504 in FIG. The transmitted analog signal passes through the data collection circuit 100, the parallel-serial conversion unit 15, and the optical signal conversion unit 16, and passes through the transmission unit 18 as serial data of the optical digital signal in the optical signal conversion unit 16. Sent. 3 and 4 exemplify 8 slices or more and 32 slices or more, respectively, the number of slices is not limited to this and may be any number. The numbers shown are only a commonly used specification. Further, although the number of channels is not shown, there is no particular limitation other than that described separately in this embodiment.

  In addition to the above structure, as shown in FIG. 5, the X-ray detector 20 and the data collection unit 100 may be integrated. Thus, in the case of the configuration in which the X-ray detector 20 and the data collection unit 100 are integrated, the problem of noise due to the antenna effect or the like generated in the flexible PC board or the connector cable can be improved. In FIG. 5, the number of slices is illustrated as 32 slices or more, but the number of slices is not limited to this and may be any number. The numbers shown are only a commonly used specification. In addition, although the number of channels is expressed as 24, there is no particular limitation other than that described separately in this embodiment. In addition, the configuration of the detection element and the data collection unit is not limited to the above, and any configuration may be used as long as incident X-rays are converted into electric or optical signals and can be processed later.

  3 to 5, the processing of steps 504 and 505 in FIG. 2 such as amplification, integration, and analog-digital conversion may be realized by a commercially available chip in the data collection unit 100, and the above functions are summarized. It may be performed by a dedicated chip called an ASIC that can be executed in this way, or another circuit element may be provided. Here, unlike a commercially available chip, the ASIC chip can reduce the number of wirings, so the number of flexible substrate lines described above can be reduced.

Next, a configuration for transmitting the signals collected by the data collection unit to the rotation unit and the relay unit of the fixed unit will be described.
The data collected by the data collection unit 100 as described above is output in parallel for each pixel when, for example, there are 24 channels × 32 slices = 768 pixels on one detection element substrate as shown in FIG. Therefore, the data is obtained from 768 or more signal lines. Here, as shown in FIG. 6, in the parallel-serial conversion unit 15, parallel signals from 768 signal lines are combined into serial signals from one signal line. This corresponds to step 506 in FIG. The combined serial signals are sent to the optical signal converter 16 in step 507 of FIG. 2, where they are converted from electrical signals to optical signals. The optical signal thus converted is sent to the input unit of the adjacent optical signal conversion unit 16B via the optical transmission unit 18A as shown in FIG. In the adjacent optical signal converter, the electrical signals from the data collectors 101B, 102B,... Electrically connected thereto are serially converted and further converted into light by the optical signal converter 16B. It is done. The serial optical signal sent from the optical transmission unit 18A is added to the signal obtained by the optical signal conversion unit 16B to become a serial signal having a new double length.

In the same manner, the adjacent optical signal converters generate longer serial signals.
Here, it is assumed that 40 X-ray detectors 20 and the data collection unit 100 are arranged. In this case, the 40th optical signal converter 16Z generates a signal 40 times as long as that obtained by each parallel-serial converter 15.
The connection method of the optical transmission unit as described above is usually called a daisy chain. The above processing corresponds to step 508 in FIG.

  Note that the optical transmission unit 18A in FIG. 7 can use a device such as an optical fiber cable that can transmit light so as not to leak, but since it is connected adjacently, an optical signal is blown into the air by optical coupling. Also good. This can reduce the wiring effort. Optical coupling refers to a configuration in which a light-emitting device such as a laser or LED and a light-receiving device such as a MOS or CCD in which the light emitted from the light-emitting device is installed within the reach of the air are arranged as a set. Optical coupling enables non-contact communication between a light emitting device and a light receiving device. Here, light is defined as a light emitting device and a light receiving device, but the communication medium is not limited to light, but may be infrared rays, ultraviolet rays, or other electromagnetic waves. In this case, the light emitting device and the light receiving device may be any devices that can receive and transmit electromagnetic waves of that wavelength.

The serial optical signal generated by the last optical signal conversion unit 16Z is sent to the control unit 17 via the optical transmission unit 18Z. The signals collected by the control unit 17 are sent to the relay unit 19, where they are transmitted from the rotating unit to the fixed unit. The above processing corresponds to step 509 in FIG. At this time, the signal transmission form may be an optical signal or may be converted into an electrical signal once. Alternatively, modulation or amplification may be performed to send from the rotating unit to the fixed unit. These signal conversion, modulation, and amplification may be performed by either the control unit 17 or the relay unit 19.
Finally, in step 510 of FIG. 2, the image processing data reaches the image processing unit 61.

Next, the data transmission capability according to this embodiment will be described.
In FIG. 7, the data collection units 101A, 102A,..., 102Z have an analog-digital conversion function with a resolution of 18 bits. Further, as the parallel-serial converters 15A to 15Z, a parallel / serial converter having a SERDES (serializer / digitalizer) circuit with a maximum speed of 1 Gbps can be used. Furthermore, as the optical signal conversion units 16A to 16Z, an optical connector having a transmission unit and a reception unit corresponding to optical transmission at the maximum speed of 1 Gbps can be used.

  When scanning is performed from the detection element substrate 2 in FIG. 7 at a view rate of 1800 View / sec, the transfer rate per detection element substrate is: view rate × number of pixels (number of slices × number of channels) × resolution = 1800 × (32 × 24) × 1825Mbps. When considering the serial-data transmission of the detection element board at the maximum transmission speed of 1 Gbps of the SERDES (serializer / digitalizer) circuit 15, it can be calculated as 1G ÷ 25M40. In other words, it is theoretically possible to transmit data of up to 40 detector element substrates in a daisy chain. In an example of the X-ray CT apparatus, since the total number of channels is about 900, and this detection element substrate is about 40, all detection element substrates can be covered with a daisy chain as shown in FIG. If the transmission speed of the parallel-serial converter 15 is slower, or if the number of pixels on the detection element substrate is larger, the optical signal converter 16 and the parallel-serial converter 15 coupled in a daisy chain are grouped into several sets. The control unit 17 may output each group separately. For example, the optical transmission unit 18G in FIG. 7 may be opened, the optical transmission units 18G and 18Z may be input to the control unit 17 in parallel, and the input unit of the optical transmission unit 16H may be opened.

Further, consider a 256-slice detector. In this case, under the same conditions as above,
View rate × number of pixels (number of slices × number of channels) × resolution = 1800 × (256 × 24) × 18200 Mbps. In other words, since the transfer rate is about 200 Mbps, about 5 daisy chains are possible. Furthermore, since the transmission speed of the 1024 slices is about 800 Mbps, a plurality of detection element substrates can be daisy chained if a parallel-serial conversion unit with a higher transmission speed, for example, 3 Gbps is used. In this case, since it depends also on the performance of the optical connector as the optical signal conversion unit, it is necessary to consider using a higher performance optical signal conversion unit.
In this way, the interface of the control unit 17 is greatly improved by using the signal that has been input to the control unit in parallel in the state of an electrical signal as the input of one optical transmission line as in this embodiment. Simplification is possible.

  In addition, the use of optical transmission also eliminates signal attenuation in high frequency electrical signals. Even when the transmission path is long, attenuation can be eliminated by using an erbium-doped fiber amplifier, which is an optical amplifier, in the middle of the optical transmission unit 18. Moreover, even if only the present confirmation is possible, parallel-serial conversion up to about 10 Gbps is possible, so that it is possible to cope with a considerable number of pixels according to the present embodiment. Furthermore, since optical transmission is resistant to noise and can be handled in a complicated manner by using an optical cable or the like, the degree of freedom to the next connection destination is large. As a result, the degree of freedom in designing the rotating part is greatly improved.

  In the first embodiment, the image processing unit 61 is placed outside the rotating unit. However, in the present example, the image processing unit 61 is mounted on the rotating unit. Since the configuration of this embodiment is a partial modification of the configuration shown in FIGS. 1 and 2 described in the first embodiment, only that portion will be described.

In FIG. 1, the case where the image processing unit 61 is installed outside the rotating unit, for example, the console, is illustrated. However, the image processing unit 61 may be mounted on the rotating side. As a result, the transmission line 64 is replaced with a configuration like the relay unit 19. At this time, the output of the image processing unit 61 is sent via the relay unit 19 to the image display unit 62 mounted on the fixed unit side console or the like. At this time, in FIG. 2, the processing by the image processing unit is performed immediately after step 507 or immediately after step 508. When the image processing unit handles an electric signal, image processing is performed after converting the optical signal into an electric signal, and the resultant electric signal is passed through the relay unit. Further, when the image processing unit handles an optical signal, the image processing may be performed with the optical signal as it is, and the optical signal obtained as a result may be passed through the relay unit. May be converted into an electrical signal.
Note that the contents described in Japanese Patent Laid-Open No. 11-244276 may be used as a configuration of optical transmission in the relay unit according to the present embodiment. This avoids errors during transmission.

  When configured as described above, transmission from the X-ray detector 2 that handles many signals to the image processing unit 61 is processed in the rotating unit while interposing optical transmission, and is reconfigured outside the rotating unit. Since only image data needs to be sent, transmission speed and image processing speed are improved in addition to noise reduction.

In the first embodiment, the optical transmission is performed from the data collection unit 1 to the control unit 17, but in this embodiment, the optical transmission is performed from the output of the data collection unit 1 to the reception unit of the relay unit 19. Since the configuration of the present embodiment is basically the same as that shown in FIGS. 1 and 2 described in the first embodiment, only step 509 and subsequent steps in FIG. 2 will be described.
FIG. 8 shows the configuration from the optical signal conversion unit 16 to the image processing unit 61 in the present embodiment.The data acquisition circuit 1, the X-ray detector 2, the X-ray tube 3, the collimator 4, The parallel-serial converter 15 and the like are not shown.

  In FIG. 8, the image reconstruction data converted into a high-frequency signal of light by the optical signal converter 16 is sent to the controller 17 via the optical transmitter 18. An optical signal amplifying unit 171 for amplifying an optical signal is provided either in the control unit or before and after the control unit. The optical signal amplifier 171 is, for example, an erbium-doped fiber amplifier. The amplified optical high-frequency signal is irradiated from a light emitting unit 191 provided at least one on the outer periphery of the rotating unit 52 via an optical fiber cable 192. The light emitting unit 191 is directed in the radial direction from the optical fiber cable 192 by a T coupler or the like. The light emitting unit 191 mounted on the rotating unit and rotating is received by the light receiving unit 193 arranged almost entirely on the inner periphery of the fixed unit at the outer periphery thereof. The light receiving unit 193 has a configuration in which a large number of photodiodes and CCDs are arranged on the circumference and includes an amplifier and an electro-optical conversion element. The received light signal is converted into an electric signal, amplified, and again, Convert to optical signal.

In the above description, a configuration in which there are a plurality of light emitting units 191 and transmits an optical signal from the inner periphery to the outer periphery to reach the image processing unit 61 is shown. However, the number of the light emitting units 191 may be one, The direction of the light receiving portion 193 may be any direction as long as it is directed to the light receiving portion 193 on the fixed portion side, and the light receiving portion 193 may be anywhere as long as it can receive a signal from the light emitting portion 191 on the fixed portion side. However, the image processing unit 61 is not limited to being disposed on the fixed unit side, and may be mounted on the rotating side. In this case, the transmission line 64 portion is transmitted by the relay unit 19.
Here, it is also possible to form an image directly from the light state by configuring the image processing unit with a computer that can directly handle the converted optical signal.

Alternatively, the optical signal received by the light receiving unit 193 of the relay unit 19 is converted into an electrical signal and then sent to the image processing device 61. Thereafter, the image processing unit performs image reconstruction, and the reconstructed image is displayed on the display device.
As in the first embodiment, the medium for transmitting a signal is not limited to light but may be electromagnetic waves having various wavelengths such as infrared rays.
Note that the contents described in Japanese Patent Laid-Open No. 11-244276 may be used as a configuration of optical transmission in the relay unit according to the present embodiment. This avoids errors during transmission.

  With the configuration as described above, the loss of photoelectric conversion is reduced, the power consumption is reduced, and the optical transmission that is resistant to electromagnetic noise and easy to mount can be widely used for the entire transmission path. As a result, the image quality and image processing speed of the reconstructed image are improved, and the degree of freedom in designing the X-ray CT apparatus is improved.

1 is an overall configuration diagram showing an entire remote service system according to an embodiment of the present invention. The flowchart for demonstrating the signal transmission of the X-ray CT apparatus by one Example of this invention. (A) The figure which shows an example of a structure of the X-ray detector and data collection part by one Example of this invention, (b) Another example of a structure of the X-ray detector and data collection part by one Example of this invention FIG. The figure which shows another example of a structure of the X-ray detector and data collection part by one Example of this invention. The figure which shows another example of a structure of the X-ray detector and data collection part by one Example of this invention. The figure which shows the principal part of the circuit structure by one Example of this invention. The figure which shows an example of the state which connected the X-ray detector by one Example of this invention, the data collection part, the parallel-serial conversion part, and the optical signal conversion part, and the optical transmission line. The figure which shows the relay of the optical transmission between the rotation part and fixed part by one Example of this invention.

Explanation of symbols

  1 data acquisition circuit, 2 X-ray detector, 3 X-ray tube, 4 collimator, 15 parallel-serial conversion unit, 16 optical signal conversion unit, 17 control unit, 18 transmission unit, 19 relay unit, 51 turntable, 52 inputs Device, 53 control device, 54 bed, 61 image processing unit, 62 image display unit

Claims (8)

An X-ray tube that emits X-rays;
An X-ray detector for detecting the irradiated X-ray;
A plurality of data collection units for collecting signals detected by the X-ray detector as electrical signals and outputting them as optical signals;
A rotating unit that mounts at least the X-ray tube, the X-ray detector, and the data acquisition unit, sandwiches the subject between the X-ray tube and the X-ray detector, and rotates around the subject;
A fixed part that supports the rotational movement of the rotating part;
A relay unit that is provided in the fixed unit and relays signal transmission between the rotating unit and the fixed unit;
An X-ray CT apparatus comprising: an image processing unit that images the signal transmitted from the data collection unit;
An X-ray CT apparatus comprising an optical signal transmission unit for transmitting a signal by connecting an output from a data collection unit to a relay unit.   The X-ray CT apparatus according to claim 1, wherein the optical transmission unit transmits a signal via at least one of an optical transmission line and air. An X-ray tube that emits X-rays;
An X-ray detector for detecting the irradiated X-ray;
A plurality of data collection units for collecting signals detected by the X-ray detector as electrical signals;
A control unit that controls the data collection unit and transmits the data obtained by the data collection unit together;
A rotating unit that mounts the X-ray tube, the X-ray detector, the data acquisition unit, and the control unit, sandwiches the subject between the X-ray tube and the X-ray detector, and rotates around the subject When,
A fixed part that supports the rotational movement of the rotating part;
In an X-ray CT apparatus comprising: an image processing unit that is provided in the fixed unit and images data transmitted from the control unit;
The rotation unit includes an optical signal conversion unit that is provided for each data collection unit and converts an output signal from the data collection unit into an optical signal, and an optical transmission unit that connects the optical signal conversion units to each other. An X-ray CT apparatus characterized by that.   The rotation unit further includes a parallel-serial conversion unit that is connected between the plurality of data collection units and the optical signal conversion unit and performs parallel-serial conversion on signals from the plurality of data collection units. The X-ray CT apparatus according to claim 3.   Each of the optical signal conversion units includes an input unit and an output unit, and an output unit of one optical signal conversion unit is connected to an input unit of another optical signal conversion unit by one of the optical transmission units, 5. The X-ray CT apparatus according to claim 3, wherein at least one input unit among all the optical signal conversion units is not connected to any other optical signal conversion unit.   6. The output of one of the optical signal converters is connected to the control unit via one of the optical transmission units. X-ray CT system.   The X-ray CT apparatus according to claim 3, wherein the optical transmission unit is at least one of an optical transmission line and air.   8. The X-ray CT apparatus according to claim 3, wherein the signal transmission between the rotating part and the fixed part is based on a combination of a slip ring and a brush or optical transmission.

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