JP2006204399A - X-ray ct apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray CT apparatus which can improve the stability and reliability of a specificity by efficiently refrigerating a converter circuit, an inverter circuit and other electric components or the like of an X-ray high-voltage apparatus mounted on a scanner rotating section even when the scanning is speeded up. <P>SOLUTION: An X-ray generating unit, an X-ray detecting unit and a scanner controlling device 9 to control a scanner are fixed to an inner peripheral surface of a rotation member 8 of the scanner rotating section, and those individual elements are incorporated and attached to the rotation member 8. An air intake aperture 19 is disposed in the rotation member 8 and the air flow at an outer peripheral side of the rotation member 8 generated by the rotation of the rotation member 8 is guided to the heat sink 14b through the air flow intake aperture 19 so that the electric components of the X-ray controlling device 14 including the semiconductor elements group for electric power 14a are refrigerated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an X-ray CT apparatus, and more particularly to an X-ray CT apparatus provided with a scanner gantry mechanism for efficiently cooling a mounting unit mounted on a scanner gantry rotating unit.

  In recent years, in X-ray CT systems, “a wide range of scanning is possible in a short time”, “continuous data can be obtained in the direction of the body axis, which enables the generation of 3D images”, and “X-ray detectors” A helical CT called a helical scan or a spiral scan having a multi-slice function having a feature such as “multiple rows of images can be taken and a large number of tomographic images can be taken at once” has been widely used.

  This spiral CT scanner gantry (hereinafter referred to as the gantry) is composed of a scanner fixing part and a scanner rotating part, and an X-ray generating unit (X-ray tube and a high voltage applied to the X-ray tube). High voltage generator and the like) and an X-ray detection unit (an X-ray detector and an amplifier for amplifying this output, etc.), a slip ring provided in the scanner fixing part, and a scanner rotating part. Electric power for generating required X-rays is supplied to the X-ray tube via a power transmission mechanism including a brush, and the scanner rotating unit is continuously rotated. The X-ray tube and the X-ray detector are spirally moved relative to the subject by continuously moving in the body axis direction of the subject.

Thus, the spiral CT must emit X-rays for a long time continuously from the X-ray tube mounted on the scanner rotating unit, so that the load on the X-ray tube increases, so a large capacity X-ray Although a tube is required, if the capacity of the X-ray tube is increased, the heat generated from the X-ray tube also increases.
Due to the temperature rise inside the gantry due to this heat generation, the inside of the gantry is cooled so that the electrical components such as the X-ray detector and high voltage generator mounted on the rotating part of the scanner are not affected by the temperature. This technique is disclosed in Patent Document 1.

In the X-ray CT apparatus disclosed in Patent Document 1, the exterior cover that covers the gantry is provided with an air intake port for taking air outside the exterior cover into the exterior cover and air inside the exterior cover. An air discharge port for discharging air to the outside of the cover is provided, and the scanner rotating part is provided with suction discharge means for sucking heat inside the outer cover and releasing the sucked heat. The inside of the scanner is cooled by taking it into the exterior cover and discharging the air inside the exterior cover to the outside of the exterior cover.
JP 2002-65659 A

Generally, an X-ray high-voltage device that generates a high voltage to be applied to the X-ray tube includes an inverter type X-ray high-voltage device in order to reduce the size and weight of the high-voltage transformer of the X-ray high-voltage device. It is used.
This inverter type X-ray high-voltage device includes a converter circuit that converts commercial AC power into DC voltage, an inverter circuit that converts the DC voltage into AC voltage having a frequency higher than the commercial power frequency, and the high-frequency AC A high voltage transformer that boosts the voltage to a high voltage and a high voltage rectifier that rectifies the boosted AC high voltage to a DC high voltage.

The converter circuit and the inverter circuit have a switching ability for conducting and non-conducting a large current of several hundred amperes, for example, for power such as an insulated gate bipolar transistor (hereinafter abbreviated as IGBT). It is composed of semiconductor elements.
This element generates power loss during the switching operation of the element from the non-conducting state to the conducting state, during the switching operation from the conducting state to the non-conducting state, and during the conducting state.
Due to this power loss, if the temperature of the power semiconductor element exceeds an allowable value, it causes thermal destruction. Therefore, in order to prevent this, the power semiconductor element generally has a large heat capacity called a heat sink with radiation fins. A method of fixing to metal and cooling it by blowing air from a fan is taken.
The motor for rotating the fan has a shaft attached in parallel with the rotation center axis of the rotating member of the scanner rotating unit.

  By installing the inverter type X-ray high-voltage device with such a configuration in the scanner rotation unit, the number of units of the X-ray CT device can be reduced to three units: a gantry, a table, and a console with a built-in image processing unit. Since it can be configured only with this, it can be installed in a small space.

  The above X-ray CT apparatus has a minimum configuration of only three units, and can perform high-speed scans with a scan time of 0.5 seconds and can be used for cardiac diagnosis. To further reduce motion artifacts In order to increase the time resolution, it is desired to further increase the scan time, that is, to make one scan time 0.5 seconds or less.

However, if the scanning time is increased, the X-ray dose per unit time must be increased in inverse proportion to the scanner rotation time as compared with a conventional apparatus having a lower speed. In other words, in order to obtain a good tomographic image with less granular noise, a large amount of current flowing between the anode and cathode of the X-ray tube (hereinafter referred to as tube current) is caused to flow in inverse proportion to the scanner rotation speed, and a sufficient X-ray dose is obtained. It is necessary to irradiate the subject.
Therefore, due to the increase in tube current flowing in the X-ray tube, the X-ray tube needs to have a larger capacity than before, and the inverter type X-ray high voltage device that supplies power to this X-ray tube also has a large output Is required.

  For this reason, the current flowing through the power semiconductor element of the converter circuit and the inverter circuit increases, the loss of the power semiconductor element increases, and the fan that cools the heat sink needs to have a large cooling capacity. Will be large.

  However, as in the conventional case, when the motor shaft of the large cooling fan is arranged in parallel with the rotation center axis of the rotary member of the scanner rotating portion and the rotary member is rotated at a higher speed than the conventional case, the rotary member The acceleration in the centrifugal direction is approximately 2.8 times that of the conventional model (when the scan time is changed from 0.5 seconds to 0.3 seconds), which greatly increases the load applied to the cooling fan motor shaft of the heat sink for heat dissipation of the power semiconductor element. There is a concern that the bearings of the fan motor may be abnormally worn and eventually damaged.

  As described above, if the scanning speed is increased more than before, the power semiconductor element cannot be cooled by the air blown from the fan. Therefore, naturally, the technique disclosed in Patent Document 1 alone is used for the power. The semiconductor element becomes insufficiently cooled, and it becomes difficult to achieve the scan time of .05 seconds or less by mounting the converter circuit and the inverter circuit on the scanner rotating unit.

  Also, as the capacity of the X-ray tube is increased by increasing the scanning time, the heat generated from the X-ray tube also increases. Therefore, the converter circuit and the inverter circuit are not mounted on the scanner rotating unit. In addition, it is necessary to take measures to prevent the waste heat from the X-ray tube from affecting the electrical components and the X-ray detector mounted on the scanner rotating unit.

  An object of the present invention is made in view of the above problems, and even if the scan time is increased, a converter circuit, an inverter circuit, and other electrical components of an X-ray high-voltage device mounted on a scanner rotating unit It is an object of the present invention to provide an X-ray CT apparatus capable of efficiently cooling the above and improving the stability and reliability of characteristics.

  The purpose of the above is to provide a cooling target portion of one or more units for generating X-rays mounted on the rotating member of the scanner gantry rotating unit with the air fluid on the outer peripheral side of the rotating member generated by the rotation of the rotating member. Specifically, it is achieved by the following means.

(1) In an X-ray CT apparatus comprising a scanner gantry rotating unit in which one or more units for generating X-rays are attached to a rotating member provided so as to be rotatable with respect to the scanner gantry fixing unit. The air fluid on the outer peripheral side of the rotating member generated by the rotation of the rotating member is used as the cooling medium of the cooling target portion of the unit, and the cooling object portion is arranged on the rotating member in the direction in which the air fluid flows.
And the air fluid taking-in means which takes in the said air fluid to the said cooling object part is provided in either one or both of the said rotation member and the said cooling object part.
In this way, the cooling target part is arranged in the flow direction of the air fluid on the outer peripheral side of the rotating member generated by the rotation of the rotating member of the scanner rotating part, and the air fluid is used as a cooling medium of the cooling target part. Since the air fluid is taken into the cooling target part by the air fluid taking-in means, the cooling target part can be efficiently cooled.
Therefore, the conventional large cooling fan mounted on the rotating member of the scanner gantry for cooling the cooling target portion is unnecessary, and high-speed scanning is possible. Further, a cooling fan is provided at the fixed part of the scanner gantry, and the scanner rotating part is stopped at a position where the cooling target part of the rotating member is cooled by the air fluid blown from the cooling fan. The object to be cooled can be cooled even during stoppage.

(2) In the case of the X-ray CT apparatus having the configuration in which the unit is attached to the inner peripheral side of the rotating member of the scanner rotating unit, the air fluid taking-in means takes in the air fluid provided in the rotating member And an air fluid introducing means for guiding the air fluid taken in from the intake port to the cooling target portion.
On the other hand, in the case of the X-ray CT apparatus configured to attach the unit to the outer peripheral side of the rotating member of the scanner rotating unit, the air fluid intake means is an air fluid introducing means for guiding the air fluid to the cooling target part. And this air fluid introduction means is provided in the said cooling object part.
With this configuration, in any X-ray CT apparatus configured to mount the unit on the inner peripheral side and the outer peripheral side of the rotating member of the scanner rotating unit, the cooling fluid is generated by the rotation of the rotating member. Can be cooled.

(3) By using the following means as the air fluid introducing means, the air fluid can be efficiently guided to the cooling target portion.
1) An intake hood member is provided at the intake port of the rotating member.
2) An intake guide member is provided at the intake port of the rotating member.
3) Air intake angle variable means is provided on the intake guide member.
4) The take-in guide member is provided with take-in guide opening / closing means that closes when the rotation member is accelerated and opens at the end of the acceleration.

(4) At least the inverter circuit of the X-ray control device including the converter circuit in the X-ray high voltage device, the inverter circuit, and the control unit for controlling these circuits, and the inverter circuit for controlling the cooling target unit. In the case of the control unit, at least a passage through which the air fluid flows is provided in a heat sink including a plurality of fins that dissipate heat generated by the power semiconductor element of the inverter circuit.
The heat sink is provided with an attachment member for attaching all or part of the X-ray control apparatus including the heat sink to the rotating member, and a guide means for guiding the air fluid is provided on the attachment member.
Thus, by providing the heat sink that dissipates heat generated by the power semiconductor elements used in the converter circuit and the inverter circuit to the fins, the passage of the air fluid can be provided to efficiently cool the power semiconductor elements. As a result, a large cooling fan is not required and high-speed scanning is possible.

(5) The air fluid can be flowed efficiently by making the shape of the heat sink as follows.
1) A heat sink with a wide entrance and a narrow exit for the passage of air fluid.
2) A heat sink having a shape having a passage for discharging the air fluid that has passed through the passage of the heat sink to the outside of the rotating member.
3) Guide means for guiding the air fluid to a mounting member that attaches all or part of the X-ray control device including the heat sink to the rotating member, and the air fluid that has passed through the passage of the heat sink to the outside of the rotating member. A heat sink with a discharge passage.

The cooling target part is arranged in a direction in which the air fluid flows on the outer peripheral side of the rotating member generated by the rotation of the rotating member of the scanner rotating part, and the air fluid is collected by using the air fluid as a cooling medium of the cooling target part. Since the air fluid is taken into the cooling target portion by the insertion means, the cooling target portion can be efficiently cooled.
In particular, the power semiconductor element is efficiently cooled by providing a passage through which the air fluid flows in a heat sink that dissipates heat generated by the power semiconductor element of the converter circuit and the inverter circuit in the X-ray high voltage apparatus to the fins. Therefore, a large cooling fan is not necessary, and high-speed scanning is possible.
In this way, even if the scan time is increased, the converter circuit, inverter circuit, and other electrical components of the X-ray high-voltage device mounted on the scanner rotating unit can be efficiently cooled to ensure stable characteristics and reliability. High X-ray CT system can be provided.

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

FIG. 1 is an external view of an X-ray CT apparatus provided with a gantry according to the present invention, and is composed of a gantry 1, a table 2 on which a subject is placed, and a console 3.
An opening 4 into which a subject is inserted is provided at the center of the gantry 1, and a table 2 is disposed on the front surface of the gantry 1.
The height of the table 2 is configured to be electrically adjustable, and a top plate 5 on which the subject is placed is provided on the upper surface of the table 2, and the top plate 5 is used for positioning the subject at the imaging position. The gantry 1 can be slid electrically.
On the console 3, an input device 6 such as a keyboard and a mouse, and a CRT monitor 7 as a display device for displaying various information such as patient information and imaging conditions and a captured tomographic image are arranged.
Inside the console 3, an image processing device (not shown) and a control device (not shown) for controlling the entire system are housed and connected to the gantry 1 and the table 2. The gantry 1 and the table 2 are It is controlled by the control device.

Hereinafter, the gantry of the X-ray CT apparatus according to the present invention will be described.
FIG. 2 is a diagram showing the configuration of the gantry of the X-ray CT apparatus according to the first embodiment of the present invention in which the X-ray generation unit and the X-ray detection unit are mounted on the inner peripheral surface of the scanner rotation unit.

  In FIG. 2, a scanner gantry 1 includes a scanner fixing unit (not shown) and a scanner rotating unit. The scanner rotating unit includes an X-ray generation unit, an X-ray detection unit, and a scanner on the inner peripheral surface of the rotating member 8. The scanner control device 9 for controlling the rotating unit is mounted, and the scanner control device 9 generates a scanner control signal corresponding to the operation command from the console 3, and the rotation of the rotary drive motor 10 based on the control signal A driving force is transmitted to the rotating member 8 through the power transmission belt 11, and the rotating member 8 is rotated at a predetermined rotational speed for scanning.

The X-ray generation unit includes an X-ray irradiation device (X-ray beam and collimator) 12 that irradiates a subject inserted in the opening 4 and placed at an imaging position, and an X-ray irradiation device 12 Commercially provided by a power transmission means comprising a high voltage generator 13 for generating a high voltage to be applied between the anode and cathode of the X-ray tube, and a slip ring provided in the scanner fixing portion (not shown) and a brush provided in the scanner rotating portion. An X-ray control device 14 that generates and controls an AC voltage having a frequency higher than the frequency of the commercial power source that is input to the high-voltage generator 13 when power from an AC power source is input, and the X-ray irradiation device 12 X An X-ray rod cooling device 15 that cools the wire rod is fixed to the inner peripheral surface of the rotating member 8.
The X-ray control device 14 and the high voltage generator 13 constitute an X-ray high voltage device, and the X-ray control device 14 includes a filament heating device for heating the filament of the X-ray tube. ing.
The X-ray irradiation apparatus includes an anode driving device that rotates the anode of the X-ray tube.

  The X-ray detection unit is disposed at a position facing the X-ray irradiation device 12 with the subject interposed therebetween, and an X-ray detector 16 for detecting X-rays transmitted through the subject, and the X-ray detector The amplifiers 17 and 18 amplify the electric signal output from 16, and are fixed to the rotating member 8.

  The X-ray control device 14 includes a power semiconductor element group 14a corresponding to a circuit configuration described later, a heat sink 14b that dissipates heat generated from the power semiconductor element group, and the commercial AC power source using a converter circuit described later. A capacitor 14c for smoothing the voltage converted into direct current, a control unit 14d for controlling the conduction time of the power semiconductor element group 14a and controlling the voltage input to the high voltage generator 13, and the respective elements electrically The wiring group 14e and the like are connected to each other.

  In this configuration, the elements of the X-ray control device 14 are integrated and fixed to the rotating member 8, and the rotating member 8 generated by the rotation of the rotating member 8 by the air fluid intake 19 provided in the rotating member 8. The air fluid on the outer peripheral side is guided to the heat sink 14b to cool the electrical components of the X-ray control device 14 including the power semiconductor element group 14a.

FIG. 3 shows a circuit configuration of an inverter-type X-ray high voltage device including the X-ray control device 14 and the high voltage generator 13.
This inverter type X-ray high voltage apparatus is configured to convert an AC voltage from a commercial AC power supply 20 by a converter circuit 21 as shown in the figure by means of power transmission means between the slip ring of the scanner fixing unit and the brush of the scanner rotating unit (not shown). The direct current voltage is smoothed by a capacitor 22 and converted into alternating current having a frequency higher than that of the commercial power source by an inverter circuit 23. The high frequency transformer 24 converts the converted high frequency alternating voltage into a predetermined tube. The voltage (voltage between the anode and cathode of the X-ray tube) is boosted to a voltage that can be obtained, and the boosted AC voltage is converted to a DC high voltage by the high voltage rectifier circuit 25, and this voltage is converted to a high voltage smoothing capacitor. 26 is applied between the anode and cathode of the X-ray tube 27 after smoothing. A filament heating circuit for heating the filament of the X-ray tube 27 to a predetermined temperature and controlling the tube current of the X-ray tube 27 is not shown.

  In the converter circuit 21 and the inverter circuit 23 of the inverter type X-ray high-voltage device, the power semiconductor element of the converter circuit 21 is configured by combining a plurality of these using a silicon rectifier to form a full-wave rectifier circuit. The AC voltage is converted into DC voltage by full-wave rectification, and an inverter circuit of a full-wave bridge is formed by combining a plurality of these using an insulated gate bipolar transistor (IGBT) for the power semiconductor element of the inverter circuit 23. This is an example using a circuit configured to convert direct current to alternating current.

  The control unit 14d is an imaging condition (tube voltage, tube current, imaging time) set by inputting from the input device 6 of the console 3, the tube voltage detected by the tube voltage detector 28 and the tube current detector 29, The tube current is input to the control unit 14d to generate a control signal that matches the detected tube voltage, the tube voltage set by the tube current, and the tube current. The control signal is supplied to the drive circuit 30 (30a, 30b, 30c, 30d) is amplified to a predetermined value, and this output is input to the gate of the IGBT of the inverter circuit 23 to control the switching of the IGBT.

In this way, the inverter type X-ray high voltage device comprises the X-ray control device 14 with the converter circuit 21, the smoothing capacitor 22, the inverter circuit 23, the control unit 14d, and the drive circuit 30 (the filament heating circuit not shown). The high voltage transformer 24, the high voltage rectifier 25, the high voltage smoothing capacitor 26, the tube voltage detector 28, and the tube current detector 29 constitute the high voltage generator 10, and the rotating member as described above. Fastens to 5.
The high voltage transformer 24, the high voltage rectifier 25, the high voltage smoothing capacitor 26, the tube voltage detector 28, the tube current detector 29, and the high voltage portion and the low voltage portion that constitute the high voltage generator 10 are insulated. The electrical components such as the heating transformer of the filament heating circuit are housed in a container filled with insulating oil for the purpose of ensuring withstand voltage and cooling.

  As described in [Problems to be Solved by the Invention], the power semiconductor elements of the converter circuit 21 and the inverter circuit 23 generate power loss during the switching operation and the conduction operation. Therefore, these power semiconductor elements are attached to the heat sink 14b.

FIG. 4 shows an example of implementation of the X-ray control device 14.
The power semiconductor elements of the silicon rectifier 14a1 of the converter circuit 21 and the insulated bipolar transistor (IGBT) 14a2 of the inverter circuit 23 are attached to a heat sink 14b made of a metal having a large heat capacity with a radiation fin 14b1, and in the vicinity thereof. A smoothing capacitor 14c and a control unit 14d are arranged as shown.
In this mounting, the shape of the heat dissipating fins 14b1 of the heat sink 14b is such that the air fluid generated by the rotation of the rotating member 8 from the air fluid intake port 19 of FIG. A plurality of groove-shaped air passages are provided, the fin is cooled with the air fluid, heat of the power semiconductor element is radiated to the fin, and the power semiconductor element is cooled.

The X-ray control device 14 mounted as shown in FIG. 4 is attached to the rotating member 8 of the gantry 1 as shown in FIG. 5 (a).
FIG. 5 (b) is a diagram showing the flow of the air fluid that flows into and out of the cooling fin 14b1 of the X-ray control device 14 that is the cooling target portion.
In FIG.5 (b), the X-ray control device 14 is provided with a mounting member 14f for mounting the control device to the rotating member 8, and the upper surface 14g of the mounting member 14f is fixed in contact with the inner wall of the rotating member 8. The mounting member 14f is attached to the rotating member so that the air fluid from the air fluid intake port 19 provided in the rotating member 8 shown in 2 passes through the groove-shaped air fluid passage provided in the heat radiating fin.

  In the first embodiment configured as described above, when an operator inputs an imaging start signal to the input device 6 of the console 3, this signal controls the entire system of the X-ray CT apparatus built in the console 3. Is transmitted from a control device (not shown) to a scanner control device 9 that controls a scanner rotation unit via a signal transmission means (not shown) using a slip ring and a brush, and the rotary member 8 is rotationally driven from the scanner control device 9 A command to rotate the motor 10 is output and a command to irradiate X-rays from the X-ray tube of the X-ray irradiation device 12 is output. Thereby, the X-ray irradiation apparatus 12 and the X-ray detection unit (X-ray detector 16 and amplifiers 17 and 18 that amplify the output of the detector) start imaging while rotating around the subject. At this time, photographing data for each predetermined rotation angle is transmitted to an image processing device (not shown) built in the console 3 via a signal transmission means (not shown) using a slip ring and a brush, and the image processing is performed. Various kinds of image processing are performed by the apparatus, and a tomographic image of the subject is displayed on the CRT monitor 7 of the console 3 after completion of imaging.

  In such an operation, since the air fluid generated by the rotation of the rotating member 8 is taken into the heat sink 14b of the X-ray control device 14, the flow of the air fluid in the X-ray control device 14 that is the cooling target portion 6, the heat dissipating fin 14b1 is cooled by the air fluid, and the heat of the power semiconductor element is dissipated to the fin.

  As a result, the power semiconductor element can be efficiently cooled, so that a conventional large fan for cooling the heat sink is not required, and the X-ray height mounted on the scanner rotating part can be increased even if the scanning time is increased. The converter circuit and inverter circuit of the voltage device can operate stably without being affected by temperature.

  Next, a modification of the structure of the rotating member of the gantry and the shape of the heat sink for cooling the power semiconductor element according to the first embodiment of the present invention will be described with reference to FIGS.

FIG. 7 shows a modification of the rotating member of the scanner rotating unit.
FIG. 7 (a) is an example in which an air fluid intake hood 31 is provided at the air fluid intake port 19 of the rotating member 8. By this, the air fluid for cooling the X-ray control device 14 as the cooling target portion is efficiently taken in. Can do.
FIG. 7 (b) is an example in which an air fluid intake guide 32 is provided at the air fluid intake port 19 of the rotating member 8.The air fluid intake guide 32 is provided with means for adjusting the angle at which the air fluid is taken in (not shown). ) By adjusting the angle to an optimum value, the X-ray control device 14 as the cooling target portion can be efficiently cooled. Further, the air fluid intake guide 32 is closed at the start of rotation of the rotary member 8, and the guide 32 is opened when the rotary member 8 reaches the set rotation speed, so that the air fluid is taken in by the amount of acceleration. The load applied to the rotating member 8 is reduced, and the rotating member 8 can reach the set rotational speed at high speed.
As a result, a series of photographing times can be shortened.

FIG. 8 shows a modification of the shape of the heat sink.
In FIG. 8 (a), the mounting member 35 attached to the rotating member is a heat sink 33 having a shape protruding from the fin 34, and the protruding portion of the mounting member 35 is the air fluid intake hood 31 or the air fluid intake guide 32 of FIG. It plays the same role as.
FIG. 8 (b) shows that the air fluid intake port of the heat sink 36 is wide, the air fluid discharge port that has passed through the fins 37 is narrowed, and it is easy to take in a lot of air fluid. It is a heat sink shaped to be faster. As described above, since the amount of air fluid to be taken in is large and the discharge speed of the warm air fluid that has passed through the fins is increased, the power semiconductor element can be efficiently cooled.
FIG. 8 (c) shows a heat sink 39 configured to discharge the air fluid that has passed through the fin 40 to the outside of the rotating member 8, and since the warmed air fluid is discharged to the outside of the rotating member, other than the X-ray control device The influence on electrical components can be reduced.
Fig. 8 (d) is a heat sink 42 in the shape of a combination of Fig. 8 (a) and Fig. 8 (c), and each feature is exhibited, and Fig. 8 (a) or Fig. 8 (c) is independently used. The cooling effect is greater than when it is used.

  Although not shown, a cooling fan is provided in the scanner fixing part of the X-ray CT apparatus having the above-described configuration, and the scanner rotating part is stopped and held at a position where the air blown from the cooling fan flows into the cooling target part. In addition, if a means for cooling with the cooling fan is provided, the cooling target portion can be cooled even when scanning is stopped, and the cooling effect can be further increased.

FIG. 9 is a diagram showing the configuration of the gantry of the X-ray CT apparatus according to the second embodiment of the present invention in which the X-ray generation unit and the X-ray detection unit are mounted on the outer peripheral surface of the scanner rotating unit.
In FIG. 9, a gantry 50 includes a scanner fixing portion (not shown) and a scanner rotating portion, and an X-ray generating unit, an X-ray detecting unit, and a scanner rotating portion on the outer peripheral surface of the rotating member 51 of the scanner rotating portion. The scanner control device 52 for controlling the operation is fixed, the scanner control device 52 generates a scanner control signal corresponding to the operation command from the console 3, and the rotational driving force of the rotational drive motor 53 is based on the control signal. Is transmitted to the rotating member 51 via the power transmission belt 54, and the rotating member 51 is rotated at a predetermined rotational speed for scanning.

The X-ray generation unit and the X-ray detection unit have the same configuration as that of the first embodiment of FIG. 2, and the difference from the first embodiment is that the heat sink 57b of the X-ray control device 57 is attached. 5 (b), FIG. 8 (a), FIG. 8 (b), FIG. 8 (c), and FIG. 8 (d) are fixed in contact with the outer peripheral surface of the rotating member 51. Therefore, it is not necessary to provide an air fluid intake port in the rotating member 51.
Further, in the second embodiment of FIG. 9 described above, the heat sink is arranged in a direction in which the flow direction of the air fluid generated by the rotation of the rotation member 50 coincides with the flow direction of the air in the air passage provided in the fin of the heat sink 57b. Since it is attached, it is not necessary to dispose the heat sink on the outer peripheral surface of the rotating member that is perpendicular to the rotating direction of the rotating member and to cool it with a large fan as in the prior art, and the large fan becomes unnecessary.

  In addition, although not shown in the drawings, a structure having the same function as the air fluid intake hood and the air fluid intake guide shown in the modification of the first embodiment may be attached to the upper surface of the heat sink 57b.

  As described above, even if the cooling target portion (X-ray control apparatus in the case of the present embodiment) is fixed on the outer peripheral surface of the rotating member, the same effect as that of the first embodiment can be obtained.

  In FIG. 9, 56 is a high voltage generator, 57 is an X-ray irradiation device, 58 is an X-ray tube cooling device, 59 is an X-ray detector, and 60 and 61 are output amplifiers of the X-ray detector.

  In the gantry X-ray CT apparatus shown in FIG. 9 configured as described above, a cooling fan is provided in the scanner fixing portion, and the scanner rotating portion is located at a position where air from the cooling fan flows into the cooling target portion. If a means for stopping and holding is used and cooling with the cooling fan is taken, the cooling target portion can be cooled even when scanning is stopped, and the cooling effect can be further increased.

  In the above embodiment, the case where the object to be cooled is an X-ray control device has been described. However, the present invention is not limited to this, and the cooling target portion is configured by an electrical component that is easily affected by the temperature mounted on the rotating member. The same effects as described above can be obtained even when applied to an apparatus such as an X-ray detector, an amplifier for amplifying this output, a scanner control apparatus, or the like.

  In the above embodiment, the silicon rectifier element is used for the power semiconductor element of the converter circuit, and the IGBT is used for the power semiconductor element of the inverter circuit. However, the present invention is limited to these power semiconductor elements. However, the present invention is effective when applied to cooling of elements using other power semiconductor elements such as thyristors and bipolar transistors.

  Furthermore, of the converter circuit and the inverter circuit, in the case of an X-ray CT apparatus in which the converter circuit is not mounted on the scanner rotating unit, it is natural that the inverter circuit and the subsequent parts should be cooled by the above means.

  In the above embodiment, the means for taking the air fluid as the cooling medium into the portion to be cooled is not limited to the air fluid intake hood and the air fluid intake guide described in the embodiment, and the air fluid is effective. Any means may be used as long as it is a means for capturing automatically. Further, the heat sink composed of fins for radiating the heat of the power semiconductor element is not limited to the above embodiment, and any shape heat sink may be used as long as the shape of the passage through which the air fluid flows effectively. .

1 is an external view of an X-ray CT apparatus according to an embodiment of the present invention. 1 is a diagram showing a configuration of a gantry of an X-ray CT apparatus according to a first embodiment of the present invention. The figure which shows the circuit structure of the inverter type | mold X-ray high voltage apparatus mounted in a scanner rotation part. Mounting diagram of the X-ray control device mounted on the scanner rotation unit. FIG. 5A is a diagram in which the mounted X-ray control device of FIG. 4 is attached to a rotating member, and FIG. 5B is a diagram showing the flow of air flowing into and out of cooling fins of the X-ray control device. The figure which shows the flow of the air in the X-ray control apparatus in a scanner rotation part. (A) is a diagram in which an air intake hood is provided at the air intake port of the rotating member, and (B) is a diagram in which an air intake guide is provided at the air intake port of the rotating member. (A) is a diagram showing a heat sink shaped to protrude the mounting member attached to the rotating member more than the fin, (B) is a diagram showing a heat sink shaped so that the air intake port is wide and the air outlet that has passed through the fin is narrow, FIG. 9C is a view showing a heat sink having a shape for discharging the air that has passed through the fins to the outside of the rotating member, and FIG. 9D is a view showing a heat sink having a shape in which FIGS. 8A and 8C are combined. The figure which shows the structure of the gantry of the X-ray CT apparatus which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

  1 scanner gantry, 2 table, 3 console, 4 openings, 5 top plate, 6 input device, 7 CRT monitor, 8 rotating member, 9 scanner control device, 10 rotation drive motor, 12 X-ray irradiation device, 13 high Voltage generator, 14 X-ray control device, 14a Power semiconductor element group, 14a1 Silicon rectifier, 14a2 Insulated gate bipolar transistor, 14b Heat sink, 14b1 fin, 14d control unit, 14f Rotating member mounting member, 16 X-ray detection 17, 18 Amplifier, 19 Air intake, 21 Converter circuit, 23 Inverter circuit, 24 High voltage transformer, 27 X-ray tube, 30 Drive circuit, 31 Air intake hood, 32 Air intake guide, 33 Heat sink, 34 Fin , 35 Mounting member, 36 Heat sink, 37 Fin, 38 Mounting member, 39 Heat sink, 40 Fin, 41 Mounting member, 42 Heat sink, 43 Fin , 44 Mounting member, 50 Scanner gantry, 51 Rotating member, 52 Scanner control device, 53 Rotation drive motor, 55 X-ray irradiation device, 56 High voltage generator, 57 X-ray control device, 57a Power semiconductor element group, 57b Heat sink , 57d control unit

Claims (10)

  An X-ray CT apparatus comprising a scanner gantry rotating unit in which one or more units for generating X-rays are attached to a rotating member provided so as to be rotatable with respect to a scanner gantry fixing unit. An air fluid on the outer peripheral side of the rotating member generated by the rotation of the rotating member is used as a cooling medium of the object to be cooled, and the cooling object portion is arranged on the rotating member in a direction in which the air fluid flows. Line CT device.   2. The apparatus according to claim 1, further comprising a cooling fan provided in the scanner gantry fixing portion, and means for stopping the scanner rotating portion at a position where the cooling target portion is cooled by air blown from the cooling fan. X-ray CT system.   3. The X-ray CT apparatus according to claim 1, wherein an air fluid intake unit that takes in the air fluid into the cooling target portion is provided in one or both of the rotating member and the cooling target portion.   4. The air fluid taking-in means of the scanner rotating portion having a configuration in which the unit is attached to the inner peripheral side of the rotating member according to claim 3, and an intake port for taking in the air fluid provided in the rotating member; An X-ray CT apparatus comprising air fluid introduction means for guiding the air fluid taken in from the inlet to the cooling target portion.   4. The air fluid intake means of the scanner rotating part configured to attach the unit to the outer peripheral side of the rotating member according to claim 3, wherein the air fluid introducing means guides the air fluid to the cooling target part. An X-ray CT apparatus characterized in that an air fluid introduction means is provided in the cooling target part.   5. The X-ray CT apparatus according to claim 4, wherein the air fluid introduction means is an intake hood member provided at an intake port of the rotating member.   5. The X-ray CT apparatus according to claim 4, wherein the air fluid introducing means is an intake guide member provided at an intake port of the rotating member.   6. The X-ray CT apparatus according to claim 5, wherein the air fluid introducing means is an intake hood member provided at the air fluid intake port of the cooling target portion.   6. The X-ray CT apparatus according to claim 5, wherein the air fluid introducing means is an intake guide member provided at the air fluid intake port of the cooling target portion.   3. The cooling circuit according to claim 1, wherein the cooling target unit is at least the inverter circuit of an X-ray control device including a converter circuit, an inverter circuit, and a control unit that controls the converter circuit of the X-ray high voltage device mounted on the rotating member. And an X-ray CT apparatus characterized by being a control unit for controlling the same.

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