JP2002345804A - X-ray tube unit and device as well as its cooling method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means for efficiently cooling an X-ray tube with less noise and less electric power. SOLUTION: The X-ray tube 50 and an X-ray detector 81 sandwiching a subject are in opposite faces where the X-ray tube unit to be loaded on a gantry 31 for use that rotates the surrounding of the subject's somatic axis (CLb), of the X-ray CT device that reforms CT tomograms of the subject according to a detection output of the X-ray detector, while an accommodation vessel 45 of X-ray tubes which hermetically contains the inner X-ray tube 50 and cooling oil as well as an oil pump 46 that outwardly circulates the cooling oil contained in the above accommodation vessel and an air-cooling radiator 61 that dissipates the heat of the cooling oil circulated by the above oil pump are provided, whereas the heat-dissipating section of the above radiator 61 is installed in an angle almost vertical to the rotational direction of the gantry 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray tube unit and apparatus, and a cooling method and a program therefor. More particularly, the present invention relates to an X-ray tube and an X-ray detector opposed to each other with an object interposed therebetween. The present invention relates to an X-ray tube unit and an X-ray CT apparatus for reconstructing a CT tomographic image of a subject based on a detection output of the apparatus, which are mounted on a gantry rotating around a subject body axis, a cooling method and a program therefor.

[0002] Today, a rotating anode type X-ray tube capable of continuously and stably obtaining high-output X-rays is widely used in X-ray CT apparatuses, but most of supplied energy is converted into heat. Since the temperature of the tube becomes high, it is necessary to cool this efficiently.

[0003]

2. Description of the Related Art FIG. 8 is a view for explaining a conventional technique.
FIG. 2 shows a perspective view of a main part of a scanning gantry section in the T apparatus. In the figure, 40 'is a conventional X-ray tube unit,
Is a collimator for limiting the X-ray irradiation range in the direction of the subject body axis CLb, 81 is an X-ray detector opposed to the X-ray tube unit 40 ′ with the subject not shown interposed therebetween, and 31 is the X-ray imaging system. A gantry 77 supporting each component unit and rotating around the body axis, and 77 is a fan for cooling the entire scanning gantry unit (inside the housing).

Further, in this X-ray tube unit 40 ', 45 seals a rotating anode type X-ray tube and its insulating / cooling oil (hereinafter simply referred to as cooling oil) inside.
An X-ray tube housing 46; an oil pump 46 for forcibly circulating the cooling oil in the housing 45 to the outside;
Is an accumulator for smoothing the flow of cooling oil circulating outside in cooperation with the oil pump 46;
A radiator unit 0 'cools the cooling oil circulating to the outside (however, a partially cutaway view is shown).

[0005] The conventional radiator unit 60 'is composed of an air-cooled radiator (cooling coil) 61 for circulating cooling oil in a coil-shaped pipe to radiate heat and a radiator 6
1 and two blowers 63 for blowing air to the cooling coil, a motor 64 for rotating and driving the blower 63, and the entire structure including the radiator 61, the blower 63 and the motor 64 are covered. A radiator cover 62 'is provided on the rear side of the cooling coil to exhaust air sucked from the air inlets 65 provided on both side surfaces thereof.

Conventionally, the air taken in from the intake port 65 by the blower 63 is blown to the radiator (cooling coil) 61 while the gantry 31 rotates at a relatively high speed (about 80 rpm) in the direction of arrow a. Met.

[0007]

However, if the air is sucked from the air inlet 65 on the side of the radiator cover as in the above-described conventional system, the blower (fan) 63 is moved by the radiator 6.
For example, the cooling efficiency of the radiator 61 has been reduced due to the reason that the cooling air flow direction of the cooling air is greatly changed due to too close contact with the radiator 61.

Further, even when the gantry is stopped, the blower 6
3 has to be rotated, so that not only the wind noise (noise) of the blower 63 is loud, but also a large amount of power is consumed for the constant drive of the blower motor 64.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide an X-ray tube unit and apparatus capable of efficiently cooling an X-ray tube with low noise and low power, and its cooling. It is to provide a method and a program.

[0010]

The above-mentioned problem is solved, for example, by referring to FIG.
Is solved. That is, in the X-ray tube unit 40 of the present invention (1), the X-ray tube 50 and the X-ray detector 81 face each other across the subject, and the CT tomography of the subject is performed based on the detection output of the X-ray detector. An X-ray tube unit mounted on a gantry 31 rotating around a subject body axis CLb of an X-ray CT apparatus for reconstructing an image, and an X-ray tube for hermetically containing an X-ray tube 50 and cooling oil therein A sphere housing container 45, an oil pump 46 for circulating the cooling oil in the housing container to the outside, and an air-cooled radiator 61 for radiating the cooling oil circulated by the oil pump are provided. The surface is provided at an angle that is substantially perpendicular to the rotation direction of the gantry 31.

According to the present invention (1), the radiation surface of the radiator 61 is provided at an angle substantially perpendicular to the rotation direction of the gantry 31 (indicated by the arrow a). Sufficient wind is applied to the heat radiation surface, so that the cooling oil circulating through the radiator 61 can be efficiently cooled with less noise and less power.

The radiator 61 of the present invention (1)
It is sufficient that the heat radiation surface is provided at an angle substantially perpendicular to the rotation direction of the gantry 31, and the mounting position is not limited to that shown in FIG. For example, as shown in FIG. 6, the radiator 61 may be provided so as to be offset left and right on the rotation trajectory of the X-ray tube container 45, or as shown in FIG. It may be provided behind the storage container 45.

Preferably, in the present invention (2), in the above-mentioned present invention (1), the radiator 61 is provided on the front surface or the rear surface in the gantry rotation direction with respect to the container 45 of the X-ray tube.

FIG. 1 shows a case where the radiator 61 is provided on the front surface of the container 45 in the gantry rotation direction a. Therefore, such an X-ray tube unit 4
0 can be formed compactly as a whole.

Preferably, in the present invention (3),
In the present invention (1) or (2), the radiator 61
And a wind tunnel member 62 for guiding the air perpendicularly to the heat radiation surface.

Accordingly, the air around the rotating gantry 31 can be efficiently introduced to the heat radiation surface of the radiator 61. FIG. 1 is a partially cutaway view of the wind tunnel member 62.

Preferably, in the present invention (4),
In the present inventions (1) to (3), for example, FIG.
As shown in the figure, a plurality of air-cooled cooling fins 48 are provided at an angle substantially parallel to the gantry rotation direction on the outer peripheral surface of the X-ray tube container 45.

Therefore, when the gantry 31 rotates, not only the cooling oil circulating in the radiator 61 but also the cooling oil in the storage container 45 can be directly, quietly and efficiently cooled by the action of the cooling fins 48.

In the X-ray CT apparatus of the present invention (5), for example, as shown in FIG. 1, the X-ray tube 50 and the X-ray detector 81 face each other across the subject, and the X-ray detector detects the X-ray. An X-ray CT apparatus for reconstructing a CT tomographic image of a subject based on an output, wherein the X-ray is fixed to a gantry 31 that rotates around a subject body axis CLb. The tube unit 40, the blower unit 70 fixed at a predetermined position around the gantry, the radiator 61 is naturally cooled by air around the gantry when the gantry is rotating, and the blower unit 70 is started up when the gantry is stopped by turning on the radiator 61. Cooling control means (not shown) for forced air cooling.

According to the present invention (5), the radiator 61 is naturally cooled by air around the gantry when the gantry is rotated, and the radiator 61 is forcedly cooled by activating the blower unit 70 when the gantry is stopped. The cooling oil of the tube can be efficiently cooled with less noise and less power as a whole device.

Preferably, in the present invention (6), in the present invention (5), a stop control means (not shown) for stopping the gantry 31 at a predetermined rotational position is provided. Therefore, the radiator 61 when the gantry is stopped can be intensively and reliably cooled by the fixed position blower unit 70.

In the method of cooling an X-ray tube unit according to the present invention (7), for example, as shown in FIG. 1, an X-ray tube 50 and an X-ray detector 81 face each other across a subject, and -Ray CT for reconstructing a CT tomographic image of the subject based on the detection output of the detector
4. The X-ray tube unit 40 according to claim 1, wherein the X-ray tube unit is fixed to a gantry in a method of cooling an X-ray tube unit used by being mounted on a gantry 31 rotating around a subject body axis of the apparatus. And a blower unit 70 fixed at a predetermined position in the periphery of the gantry. When the gantry is rotated, the radiator 61 is naturally cooled by the air in the periphery of the gantry, and when the gantry is stopped, the blower unit 70 is activated to force the radiator 61. Air cooling.

The program of the present invention (8) is a computer-executable program for causing a computer to execute the cooling method of the present invention (7).

Such a program includes a CD-ROM,
It can be provided to the X-ray CT apparatus by recording it on a recording medium such as a CD-R / W or by online distribution via a wired / wireless communication line.

[0025]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that the same reference numerals indicate the same or corresponding parts throughout the drawings.

FIG. 2 is a functional block diagram of an X-ray CT apparatus according to the embodiment. This apparatus is roughly divided into an X-ray fan beam XLFB and an X-ray fan beam XLFB.
Scanning gantry 30 for helical scanning and reading
And an imaging table 20 on which the subject 100 is placed and moved in the direction of the body axis CLb, and a remote operation console unit 10 for controlling these and operating an X-ray imaging technician or the like.

In the scanning gantry section 30, reference numeral 40 denotes an X-ray tube unit according to the embodiment (details will be described later);
Is a rotating anode type X-ray tube, 50A is an X-ray controller, and 80 is an X-ray tube.
A collimator that limits the exposure range of the line in the direction of the body axis CLb,
80A is a collimator control unit, and 81 is a large number (n = about 1000) of X-ray detecting elements arranged in the channel CH direction.
An X-ray detector (multi-detector) 82 arranged in, for example, four rows in the Lb direction generates a projection data of the subject 100 based on a detection signal of the X-ray detector 81 and collects the data. Reference numeral 31 denotes a gantry that rotatably supports the constituent units constituting the X-ray imaging system around the body axis CLb, and 31A denotes a rotation control unit that controls the rotation of the gantry 31.

The X-ray detector 81 may have an arbitrary number of one or more rows other than the above. FIG. 2 additionally shows x, y, and z coordinates fixed to the scanning gantry unit 30. Here, the z-axis is parallel to the direction of the subject body axis CLb.

In the operation console unit 10, X is X
A central processing unit for performing main control and processing (scan control, CT tomographic image reconstruction processing, etc.) of the X-ray CT apparatus;
PU, 11b are RAM, ROM used by CPU 11a
A memory (MM) 12 for inputting commands and data including a keyboard, a mouse, and the like; 13, a display device (CRT) for displaying a scan plan and a scanned / reconstructed CT tomographic image; 14 is a control interface for exchanging various control signals CS and monitor signals MS between the CPU 11a and the scanning gantry 30 and the imaging table 20, 15 is a data collection buffer for temporarily accumulating projection data from the data collection unit 82, A secondary storage unit 16 stores and stores various application programs necessary for control and operation of the X-ray CT apparatus, various calculation / correction data files, and the like, as well as finally storing and storing the projection data of the data acquisition buffer 15. It is a storage device (such as a hard disk device).

The cooling control means of the blower unit 70 in the present invention (5) and the stop control means of the gantry 31 in the present invention (6) are realized by executing a program of the CPU 11.

The operation of X-ray CT imaging with this configuration will be outlined. The X-ray fan beam XLFB from the X-ray tube 50 passes through the subject 100 and is simultaneously incident on each detection row of the X-ray detector 81. The data collection unit 82 integrates and A / D converts each channel detection current signal of the X-ray detector 81 to generate corresponding projection data g ₁ (X, θ) to g ₄ (X, θ),
The data is stored in the data collection buffer 15. In addition, gantry 3
Projection similar to the above is performed at each view angle θ where 1 is slightly rotated, and thus projection data for one rotation of the gantry is collected and accumulated.

Further, the imaging table 20 is moved intermittently / continuously in the body axis direction of the subject 100 in accordance with the axial / helical scan method, and thus all projection data of a required imaging area of the subject 100 is collected and accumulated. Finally, these are stored in the secondary storage device 16. And
The CPU 11a executes the object 1 based on the obtained projection data in parallel with or after the scan.
The CT tomographic image of 00 is reconstructed and displayed on the display device 13. Next, the mechanical configuration of the scanning gantry unit 30 will be described.

FIG. 3 is a structural view of a main part of the scanning gantry unit according to the embodiment, and shows a mechanical structure of the scanning gantry unit 30. FIG. 3A is a front view, and FIG. 3B is a side view. In the drawing, reference numeral 91 denotes a bearing mechanism (fixing portion) that rotatably supports the gantry 31; 92, a bearing;
93 is a motor for driving the gantry 31, and 94 is a motor 93
Reference numeral 95 denotes a V-belt which transmits the rotational driving force of the pulley to the gantry 31.

An example of the X-ray tube unit 40 includes a container 45 for sealing and containing a rotating anode type X-ray tube and its cooling oil therein, and forcing the cooling oil in the container 45 to the outside. An oil pump 46 for circulation, an accumulator 47 for assisting the oil pump 46, and an air-cooled radiator unit 60 for cooling cooling oil circulating outside are provided. Details of each part will be described later.

On the other hand, the X-ray tube unit 40 is provided with a blower unit 70 provided at a fixed position of the gantry unit housing separately from the X-ray tube unit 40, and the X-ray tube unit 40 (particularly, the radiator unit 60) stopped at the fixed position is forcibly air-cooled. It is possible.

The cooling operation of the X-ray tube unit 40 will be briefly described.
5 and the gantry 3
When 1 rotates in the direction of arrow a at, for example, about 80 rpm,
The radiator unit 60 receives the wind accompanying the rotation of the gantry and naturally cools the cooling oil circulating therein. When the scan is completed and the gantry 31 stops at the fixed position, the blower unit 70 is activated to forcibly cool the radiator unit 60 by air.

It is to be noted that an example configuration for always stopping the gantry 31 at a fixed position is further provided. In the figure, reference numeral 32 denotes a plurality of markers (including a home position marker) provided at predetermined intervals on the peripheral surface of the gantry 31 by printing or the like, and 33 denotes an optical detector for detecting the passage of the marker 32. The light-emitting diode includes a light-emitting diode that irradiates light to the passing portion of the marker 32 and a phototransistor that detects reflected light from the marker passing portion. Also, 3
4 is a gantry 3 that has been decelerated to a low speed after scanning is completed.
1 is a brake mechanism for completely stopping at a fixed position and holding the stop.

With this configuration, the rotation speed of the gantry can be detected by measuring the detection pulse interval of each marker while the gantry is rotating. Further, in a state where the gantry 31 is decelerated to a predetermined low speed, the gantry 31 is completely braked when a predetermined number of markers are always detected from when the home position marker is detected. Thereby, the gantry 31 is always stopped at the fixed position. When the gantry 31 is started, the braking is released.

In place of the marker 32 formed by printing or the like, a magnetic material (permanent magnet or the like) is buried at a predetermined interval, and a passing magnetic field (N / S pole) is formed by a coil, a Hall element, a magnetoresistive element, or the like. You may comprise so that it may pick up. This makes it possible to construct a pickup system that is resistant to dirt.

FIG. 4 is a structural view of a main part of the X-ray tube unit according to the embodiment, FIG. 4 (A) is a front view, FIG. 4 (B) is a plan view seen from above, and FIG. It is the side view seen from the radiator side.

FIG. 4B is a sectional view of the X-ray tube container 45. A cylindrical support member 54 made of a synthetic resin or the like is fixed inside the container 45, thereby fixing and supporting the X-ray tube 50 inside the container. This X-ray tube 5
Reference numeral 0 denotes a glass envelope 51 for keeping the inside of the tube in a vacuum, a filament (cathode) 52 for generating thermoelectrons, and a target (rotary anode) 5 made of a facing umbrella-shaped tungsten disk or the like.
3, a rotating anode element (rotor) 53a integrally formed with the target 53, and a support structure for an X-ray tube anode shaft including a bearing 55 for rotatably supporting the rotor 53a. On the other hand, a stator is provided inside the support member 54.
A (stator coil) 56 is embedded, and generates a rotating magnetic field (about 130 to 160 Hz) to be applied to the rotor.

When a rotating magnetic field is generated in the stator 56, an eddy current flows in the rotor, and the rotating anode 53 rotates at a predetermined speed (780).
(0-9600 rpm). In this state, the thermoelectrons generated in the filament 52 are accelerated by a high voltage kV.
Focus and collide with a small focus on target 53, X
Generate a line. In order to sufficiently cool the heat generated in the rotating anode 53 at that time and to sufficiently maintain insulation between the rotating anode 53 and the container 45, a cooling oil (insulating oil) is previously provided in the container 45. Are filled to capacity.

Referring also to FIG. 4A, the cooling oil is sucked by an oil pump 46 via a pipe 41a, introduced into an accumulator 47 via a pipe 41b, and furthermore through a pipe 41c. Radiator unit 6
It is led to 0.

In FIG. 4C, the radiator unit 60 is provided so as to surround a periphery of the radiator 61 with a radiator 61 having a front surface (a plane in the drawing) as a cooling surface (radiation surface). A rectangular duct-shaped wind tunnel member 6 for guiding air perpendicular to the heat dissipation surface
2 is provided.

The radiator 61 is bent in parallel with the heat radiating surface to circulate the cooling oil therein, and the radiator 61 is in contact with (attached to) the cooling coil 61a to assist the heat radiation of the cooling coil 61a. And a plurality of cooling fins 61b for cooling the cooling oil in the cooling coil efficiently by air passing perpendicularly to the heat radiating surface. One example of the wind tunnel member 62 is provided such that the area of the intake port is larger than the area of the exhaust port, whereby a large amount of cold air is taken in from the outside (around the gantry 31), and the cold air is supplied between the cooling fins 61b. At a high speed, thereby increasing the heat radiation effect of the cooling oil.

Further, the cooling oil radiated by the cooling coil 61a is sucked by the oil pump 46 via the pipe 41d, and is returned to the X-ray tube container 45 via the pipe 41e.

FIG. 5 is a flowchart of the X-ray CT imaging processing according to the embodiment. The control sequence is such that the X-ray tube unit 40 is naturally cooled by the scan operation of the subject, and forcedly cooled by the blower unit 70 when the scan is stopped. Is shown. This control is executed by the CPU 11a.

Preferably, a scout scan (corresponding to two-dimensional X-ray imaging) of the subject 100 is performed in advance, and then input to this processing. In this state, the X-ray tube unit 40 is stopped at a fixed position, and is forcedly cooled by the blower unit 70. In step S11, the technician sets scan parameters, and in step S12, presses a "CONFIRM" button. In step S13, the X-ray tube 50 is started based on the set scan parameters (tube voltage kV, tube current mA, etc.). Step S
At 14, it is determined whether or not the gantry 31 needs to be tilted.
If necessary, the gantry 31 is tilted in step S15, and if not, the process in step S15 is skipped.

In step S16, the rotation of the gantry 31 is started, and in step S17, the rotation of the blower unit 70 is stopped. As a result, the gantry 31 rotates, and the X-ray tube unit 40 (particularly, the radiator 61) is naturally cooled by the cool air accompanying the rotation of the gantry 31. On the other hand, by stopping the blower unit 70 in this section, wind noise (noise) and power consumption can be reduced.

In step S18, the photographing table 20 is moved to the scanning position, and in step S19, the completion of the scan preparation for each of the activated units is awaited.

In this way, when the scan preparation is completed, the X-ray imaging technician proceeds to step S20 by clicking "START".
The user presses the "SCAN" button to start scanning (X-ray irradiation) and reading from the first scan position. In step S21, the subject is scanned and projection data is collected. In step S22, it is determined whether or not the scanning of all the processes is completed. If not, the process returns to step S21.

Thus, when the scanning is completed,
In step S23, the blower unit 70 is started, and in step S24, the gantry 31 is stopped at a fixed position. Accordingly, the X-ray tube unit 40 (particularly, the radiator 61) stopped at a fixed position is forcibly moved by the blower unit 70.
It is intensively air-cooled.

In step S25, a CT tomographic image of the subject is reconstructed based on the obtained projection data. In step S26, the obtained CT tomographic image is displayed on the display device 13.

FIGS. 6 and 7 are main part configuration diagrams (1) and (2) of a scanning gantry according to another embodiment. FIG. 6 shows various arrangements of the radiator unit 60. FIG. The radiator unit 60 only needs to be provided at an angle at which the heat radiation surface of the radiator 61 is substantially perpendicular to the rotation direction of the gantry 31, and the mounting position is not limited to that shown in FIG. For example, as shown in FIG. 6, the radiator unit 61 may be provided so as to be offset left and right on the rotation trajectory of the X-ray tube container 45. In this case, since there is no obstacle (such as the X-ray tube container 45) in the intake and exhaust paths of the radiator unit 60, the cooling efficiency of the radiator 61 is improved. Alternatively, as shown in FIG. 6, the radiator unit 60 is connected to the X-ray tube container 4.
5 may be provided behind. Even with such an arrangement, sufficient cooling efficiency can be obtained.

FIG. 7A shows a case where the mounting position of the blower unit 70 is different from that of FIG.
As shown, the radiator unit 60 when the gantry is stopped
The gantry 31 can be stopped so that the heat radiating surface faces the ceiling of the scanning gantry section 30. In this case, the blower unit 7
As 0, one or more cooling fans 73 on the ceiling of the scanning gantry unit 30 can be used. Preferably, the duct 7
In step 4, the cool air is guided to the radiator unit 60, and the radiator unit 60 when the gantry is stopped is forcibly and intensively air-cooled.

FIG. 7B shows another example of the tube container 45. The storage container 45 of this example is provided with a plurality of cooling fins 48 on its outer periphery to improve cooling efficiency. FIG. 7B is a partially cutaway view of the wind tunnel member 62.

In the above embodiment, an example in which the invention is applied to an X-ray CT apparatus using a fan beam system (a so-called RR system) has been described. It is apparent that the present invention can be applied to an X-ray CT apparatus of a so-called RS system or the like which is arranged in a plurality of rows in a ring shape concentric with the orbit. Even in this case, the rotating X-ray tube unit is efficiently cooled by natural air.

Although a plurality of preferred embodiments of the present invention have been described, it is needless to say that various changes can be made in the configuration, control, and combination of these components without departing from the spirit of the present invention. There is no.

[0059]

As described above, according to the present invention, the X-ray tube can be efficiently cooled with less noise and less power.
This greatly contributes to improving the maintainability and operation reliability of the tube unit.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a functional block diagram of the X-ray CT apparatus according to the embodiment.

FIG. 3 is a configuration diagram of a main part of a scanning gantry unit according to the embodiment.

FIG. 4 is a main part configuration diagram of an X-ray tube unit according to the embodiment.

FIG. 5 is a flowchart of an X-ray CT imaging process according to the embodiment.

FIG. 6 is a configuration diagram (1) of a main part of a scanning gantry according to another embodiment.

FIG. 7 is a main configuration diagram (2) of a scanning gantry section according to another embodiment.

FIG. 8 is a diagram illustrating a conventional technique.

DESCRIPTION OF SYMBOLS 10 Operation console unit 20 Imaging table 30 Scanning gantry unit 31 Gantry 40 X-ray tube unit 45 X-ray tube storage container 46 Oil pump 47 Accumulator 48 Cooling fin 50 X-ray tube 60 Radiator unit 61 Radiator 61a Cooling Coil 61b Cooling fin 62 Wind tunnel member 70 Blower unit 71 Blower 72 Motor 80 Collimator 81 X-ray detector 82 Data acquisition unit (DAS) 91 Bearing mechanism 92 Bearing 93 Motor 94 Pulley 95 V belt 100 Subject

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuhiko Hayakawa 127-7 Asahigaoka, Hino-shi, Tokyo Inside GE Yokogawa Medical Systems Co., Ltd. (72) Inventor Katsumasa Nose 4-77 Asahigaoka, Hino-shi, Tokyo 127 GE Yokogawa Medical System Corporation F-term (reference) 4C092 AA01 AB26 AB30 AC01 AC17 BD17 BE02 4C093 AA22 BA03 CA35 EC45

Claims (8)

[Claims] An X-ray tube and an X-ray detector face each other across a subject, and a CT of the subject is detected based on a detection output of the X-ray detector.
An X-ray tube unit mounted on a gantry rotating about an object body axis of an X-ray CT apparatus for reconstructing a tomographic image, comprising: an X-ray tube in which an X-ray tube and cooling oil are sealed and housed; A storage container, an oil pump that circulates cooling oil in the storage container to the outside, and an air-cooled radiator that radiates the cooling oil circulated by the oil pump, wherein a radiator of the radiator has a heat radiation surface in a rotating direction of the gantry. An X-ray tube unit provided at an angle substantially perpendicular to the X-ray tube. 2. The X-ray tube unit according to claim 1, wherein the radiator is provided on a front surface or a rear surface of the X-ray tube in the gantry rotation direction with respect to the container. 3. The X-ray tube unit according to claim 1, further comprising a wind tunnel member for guiding air perpendicular to a heat radiation surface of the radiator. 4. A plurality of air-cooled cooling fins are provided at an angle substantially parallel to the gantry rotation direction of the outer peripheral surface of the container of the X-ray tube. The X-ray tube unit according to one. 5. An X-ray tube and an X-ray detector are opposed to each other across a subject, and CT of the subject is detected based on a detection output of the X-ray detector.
An X-ray CT apparatus for reconstructing a tomographic image, wherein the X-ray tube unit according to any one of claims 1 to 3 fixed to a gantry rotating around an object body axis, and a predetermined part around the gantry. A blower unit fixed to a position, and cooling control means for naturally cooling the radiator with air around the gantry when the gantry rotates, and for cooling the radiator by forcibly cooling the radiator when the gantry stops. X-ray CT device. 6. The X-ray CT apparatus according to claim 5, further comprising stop control means for stopping the gantry at a predetermined rotation position. 7. An X-ray tube and an X-ray detector face each other across a subject, and the CT of the subject is detected based on a detection output of the X-ray detector.
4. A method for cooling an X-ray tube unit mounted on a gantry rotating around an object body axis of an X-ray CT apparatus for reconstructing a tomographic image, wherein the X-ray tube unit is fixed to the gantry. And a blower unit fixed at a predetermined position around the gantry.The radiator is naturally cooled by air around the gantry when the gantry rotates, and the blower unit is activated when the gantry stops. A method for cooling an X-ray tube unit, comprising forcibly cooling a radiator with air. 8. A computer-executable program for causing a computer to execute the cooling method according to claim 7.