CABINET FOR MRI SYSTEM
With a view to cooling components for an MRI system neither more nor less and without the generation of noise or without a fear of moisture condensation, a component for which cooling with air suffices, out of the components for an MRI system, is cooled as an air-cooled component with cold air which is blown down from an air conditioner indoor machine, while a component to be cooled with air, out of the components for an MRI system, is cooled with cooling water.
The present invention relates to a cabinet for an MRI (Magnetic Resonance Imaging) system and more particularly to a cabinet for an MRI system able to cool components for the MRI system neither more nor less and without generating a noise or without a fear of moisture condensation.
Heretofore there has been known a surface temperature adjusting method for a magnet for an MRI system which method detects the temperature of the magnet and air-condition a room where the MRI system is installed to maintain the temperature of the magnet at an appropriate temperature (see, for example, Patent Literature 1).
A power supply unit for an air-cooled type MRI system is also known (see, for example, Patent Literature 2).
Further known is an MRI system wherein a coil is water-cooled (see, for example, Patent Literature 3).
[Patent Literature 1] Japanese Unexamined Patent Publication No. Hei 6 (1994) -165766
[Patent Literature 2] Japanese Unexamined Patent Publication No. 2000-139873
[Patent Literature 3] Japanese Unexamined Patent Publication No. 2004-267405
For example, a memory and a gradient amplifier are considered as components for an MRI system. The quantity of heat generated from a gradient amplifier is several times as large as that of a memory.
Therefore, in case of air-conditioning a room with components for an MRI system installed therein to maintain the temperature of components for the MRI system at an appropriate temperature as in the above conventional surface temperature adjusting method for a magnet for an MRI system, if the air conditioning is performed in conformity with the quantity of heat generated from the memory, there occurs insufficiency for the gradient amplifier. On the other hand, if the air conditioning is performed in conformity with the quantity of heat generated from the gradient amplifier, there occurs excess for the memory or an increase of noise of a fan which rotates at high speed for ensuring a required wind volume.
Cooling the components for the MRI system with water is considered as a solution to this problem, but if water cooling is performed in conformity with the quantity of heat generated from the memory, there occurs insufficiency for the gradient amplifier. On the other hand, if water cooling is performed in conformity with the quantity of heat generated from the gradient amplifier, there occurs excess for the memory, with a consequent fear of moisture condensation due to supercooling.
SUMMARY OF THE INVENTIONIt is desirable that problems described previously are solved.
In a first aspect of the invention there is provided a cabinet for an MRI system, comprising an indoor machine of a cooler adapted to blow down cold air, an air-cooled component including an electronic part installed below the cooler indoor machine and cooled with the cold air, and a water-cooled component including an electronic part installed below the air-cooled component and cooled with circulating cooling water.
In the cabinet for an MRI system according to the above first aspect, a component cooled sufficiently with air out of the components for the MRI system is cooled as an air-cooled component with cold air which is blown down from the cooler indoor machine. On the other hand, of the components for the MRI system, a component to be cooled with air is cooled with cooling water as a water-cooled component. That is, the components for the MRI system can be cooled neither more nor less. Besides, since air cooling is performed for only the air-cooled component, it is not necessary to rotate a fan at high speed and hence a noise does not occur. Further, since water cooling is performed for only the water-cooled component, moisture condensation caused by supercooling does not occur.
In a second aspect of the invention there is provided, in combination with the above first aspect, a cabinet for an MRI system wherein the heat of the cooler indoor machine is discharged outdoors by an outdoor machine of the cooler.
The heat from the cooler indoor machine may be discharged indoors, but the discharged heat may exert a bad influence on the indoor environment.
Therefore, in the cabinet for an MRI system according to the above second aspect, the heat from the cooler indoor machine is discharged outdoors by the cooler outdoor machine. Therefore, it is possible to prevent the discharged heat from exerting a bad influence on the indoor environment.
In a third aspect of the invention there is provided, in combination with the above first or second aspect, a cabinet for an MRI system wherein the cooling water circulates from the water-cooled component to the outdoors with dissipation of heat and then returns to the water-cooled component.
The heat from the cooling water of an increased temperature may be dissipated indoors, but the dissipated heat may exert a bad influence on the indoor environment.
Therefore, in the cabinet for an MRI system according to the above third aspect, the cooling water of an increased temperature is conducted outdoors, allowing its heat to be dissipated outdoors. Thus, it is possible to prevent the dissipated heat from exerting a bad influence on the indoor environment.
In a fourth aspect of the invention there is provided, in combination with any of the above first to third aspects, a cabinet for an MRI system further comprising a heat insulating material for heat-insulating the air-cooled component and the water-cooled component from the exterior.
When the transfer of heat is performed between the interior and the exterior through a cabinet case, there may occur a case where one exerts a bad influence on the other.
Therefore, in the cabinet for an MRI system according to the above fourth aspect, the interior and the exterior of the cabinet are heat-insulated using a heat insulating material. As a result, the transfer of heat can no longer be performed between the interior and the exterior of the cabinet and it is possible to prevent one from exerting a bad influence on the other.
In a fifth aspect of the invention there is provided, in combination with any of the above first to fourth aspects, a cabinet for an MRI system including a digital signal processing circuit as the electronic part of the air-cooled component.
In the cabinet for an MRI system according to the above fifth aspect, not water cooling, but air cooling is performed for a digital signal processing circuit which generates heat in a smaller quantity than a power circuit. As a result, it is possible to prevent the digital signal processing circuit from being supercooled.
In a sixth aspect of the invention there is provided, in combination with the above fifth aspect, a cabinet for an MRI system wherein the digital signal processing circuit includes a CPU and a memory.
In the cabinet for an MRI system according to the above sixth aspect, not water cooling, but air cooling is performed for a CPU and a memory both generating heat in a smaller quantity than the power circuit. As a result, it is possible to prevent the CPU and memory from being supercooled.
In a seventh aspect of the invention there is provided, in combination with any of the above first to sixth aspects, a cabinet for an MRI system including a power circuit as the electronic part of the water-cooled component.
In the cabinet of an MRI system according to the above seventh, not air cooling, but water cooling is performed for a power circuit which generates a large quantity of heat. As a result, the power circuit can be cooled sufficiently.
In an eighth aspect of the invention there is provided, in combination with the above seventh aspect, a cabinet for an MRI system wherein the power circuit includes an RF amplifier and a gradient amplifier.
In the cabinet for an MRI system according to the above eighth aspect, not air cooling, but water cooling is performed for an RF amplifier and a gradient amplifier both generating a large quantity of heat. As a result, the RF amplifier and the gradient amplifier can be cooled sufficiently.
In the cabinet for an MRI system according to the invention, of the components for the MRI system, a component for which air cooling suffices is cooled with cold air blown down from the cooler outdoor machine, while a component to be cooled with water is cooled with cooling water, each component can be cooled neither more nor less. Besides, since air cooling is performed for only the air-cooled component, it is necessary to rotate the fan at high speed and hence a noise does not occur. Likewise, since water cooling is performed for only the water-cooled component, moisture condensation caused by supercooling does not occur.
The cabinet for the MRI system according to the invention can be utilized for obtaining a tomographic image of a subject.
Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings.
The invention will be described below in more detail by way of embodiments thereof. However, the invention is not limited by the following embodiments.
First EmbodimentIn the MRI system 100, a magnet assembly 1 has a spatial portion (bore) for insertion therein of a subject and includes, in a surrounding relation to the spatial portion, an X-axis gradient coil 1X for forming an X-axis gradient magnetic field, a Y-axis gradient coil 1Y for forming a Y-axis gradient magnetic field, a Z-axis gradient coil 1Z for forming a Z-axis gradient magnetic field, a transmission coil 1T to provide RF pulses for exciting a spin of an atomic nucleus in the subject, a receiving coil 1R for detecting an NMR signal generated from the subject, and a pair of permanent magnets 1M for forming a static magnetic field.
Superconducting magnets may be used instead of the pair of permanent magnets 1M.
The X-axis gradient coil 1X, Y-axis gradient coil 1Y, Z-axis gradient coil 1Z and transmission coil 1T are connected to an X-axis gradient coil driver 3X, Y-axis gradient coil driver 3Y, Z-axis gradient coil driver 3Z and RF power amplifier 4, respectively.
The X-axis gradient coil driver 3X, Y-axis gradient coil driver 3Y, Z-axis gradient coil driver 3Z and RF power amplifier 4 include an X-axis gradient amplifier, Y-axis gradient amplifier, Z-axis gradient amplifier and RF amplifier, respectively.
In accordance with a command issued from a computer 7 a sequence memory 8 operates the gradient coil drivers 3X, 3Y and 3Z on the basis of a pulse sequence stored therein, causing gradient magnetic fields to be generated from the gradient coils 1X, 1Y and 1Z, and at the same time operates a gate modulator 9 to modulate a carrier output signal provided from an RF oscillator 10 into a pulse signal having a predetermined timing, a predetermined envelope shape and a predetermined phase. The pulse signal is then applied as an RF pulse to an RF power amplifier 4, in which it is power-amplified, then the thus-amplified signal is applied to the transmission coil 1T.
The receiving coil 1R is connected to a preamplifier 5.
The preamplifier 5 amplifies an NMR signal provided from a subject and received by the receiving coil 1R and inputs it to a phase detector 12. In accordance with a reference signal outputted from the RF oscillator 10 the phase detector 12 detects the phase of an NMR signal provided from the preamplifier 5 and provides the detected signal to an AD converter 11. The AD converter 11 converts an analog signal after the phase detection into digital data and inputs the digital data to the computer 7.
The computer 7 not only takes charge of an overall control such as receiving information inputted from an operator console 13, but also reads digital data from the AD converter 11, performs an arithmetic operation to generate an image and display the image and a message on a display 6.
The computer 7 includes a CPU and a memory.
The cabinet 200 for the MRI system is provided with an air conditioner indoor machine 30 adapted to suck up air whose temperature has risen within the cabinet and blow down moisture-adjusted cold air into the cabinet, an air-cooled component 40 installed below the air conditioner indoor machine 30 and cooled with air, a water-cooled component 50 installed below the air-cooled component 40 and cooled with water, and a heat insulating material 70 which covers the surface of the cabinet.
The computer 7 is accommodated in a computer unit 41 of the air-cooled component 40. The sequence memory 8, gate modulator 9 and RF oscillator 10 are accommodated in a transmission unit 42. The preamplifier 5, phase detector 12 and AD converter 11 are accommodated in a receiving unit 43. An interface circuit for the display 6 and the operator console 13 is accommodated in an IO unit 44.
A stabilized power supply is accommodated in a stabilized power supply unit 51 of the water-cooled component 50. The RF power amplifier 4 is accommodated in an RF unit 52. The X-axis gradient coil driver 3X and a power supply for the X-axis gradient coil are accommodated in an X-axis gradient unit 53. The Y-axis gradient coil driver 3Y and a power supply for the Y-axis gradient coil are accommodated in a Y-axis gradient unit 54. The Z-axis gradient coil driver 32 and a power supply for the Z-axis gradient coil are accommodated in a Z-axis gradient coil 55.
An air conditioner pipe 32 leaves the air conditioner indoor machine 30, extends through a wall W and gets into an air conditioner outdoor machine 31. A refrigerant circulates through the air conditioner pipe 32 and the heat from the air conditioner indoor machine 30 is discharged outdoors by the air conditioner outdoor machine 31.
A cooling water pipe 62 leaves the water-cooled component 50, extends through the wall W and gets into a cooling water pump chiller 61 disposed outdoors. Cooling water whose temperature has risen within the water-cooled component 50 passes through the cooling water pipe 62, gets into the cooling water pump chiller 61, dissipates heat in the cooling water pump chiller 61 to reduce the temperature thereof, then passes through the cooling water pipe 62 and returns to the water-cooled component 50.
The following effects are obtained by the MRI system 100 and the cabinet 200 for the MRI system according to the first embodiment.
(1) Since the air-cooled component 40 is cooled with cold air and the water-cooled component 50 is cooled with cooling water, both can be cooled neither more nor less.
(2) Since only the air-cooled component 40 smaller in the amount of heat generated than the water-cooled component 50 is cooled with air, it is not necessary to rotate the fan at high speed and hence the generation of noise does not occur.
(3) Since only the water-cooled component 50 large in the amount of heat generated is cooled with water, there is no fear of the component small in the amount of heat generated being supercooled with moisture condensation.
(4) Since the cabinet in question is independent of the room temperature environment, it can be installed in any desired place, for example, an operation room or a machine room and therefore it is possible to enhance the degree of freedom of the installation place.
Second EmbodimentPropylene glycol or ethylene glycol may be used as cooling water.
Many widely different embodiments of the invention may be configured without departing from the spirit and the scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.
Claims
1. A cabinet for an MRI system, comprising an indoor machine of a cooler adapted to blow down cold air, an air-cooled component including an electronic part installed below the cooler indoor machine and cooled with the cold air, and a water-cooled component including an electronic part installed below the air-cooled component and cooled with circulating cooling water.
2. A cabinet for an MRI system according to claim 1, wherein the heat of the cooler indoor machine is discharged outdoors by an outdoor machine of the cooler.
3. A cabinet for an MRI system according to claim 1, wherein the cooling water circulates from the water-cooled component to the outdoors with dissipation of heat and then returns to the water-cooled component.
4. A cabinet for an MRI system according to claim 2, wherein the cooling water circulates from the water-cooled component to the outdoors with dissipation of heat and then returns to the water-cooled component.
5. A cabinet for an MRI system according to claim 1, further comprising a heat insulating material for heat-insulating the air-cooled component and the water-cooled component from the exterior.
6. A cabinet for an MRI system according to claim 2, further comprising a heat insulating material for heat-insulating the air-cooled component and the water-cooled component from the exterior.
7. A cabinet for an MRI system according to claim 3, further comprising a heat insulating material for heat-insulating the air-cooled component and the water-cooled component from the exterior.
8. A cabinet for an MRI system according to claim 1, including a digital signal processing circuit as the electronic part of the air-cooled component.
9. A cabinet for an MRI system according to claim 2, including a digital signal processing circuit as the electronic part of the air-cooled component.
10. A cabinet for an MRI system according to claim 3, including a digital signal processing circuit as the electronic part of the air-cooled component.
11. A cabinet for an MRI system according to claim 5, including a digital signal processing circuit as the electronic part of the air-cooled component.
12. A cabinet for an MRI system according to claim 8, wherein the digital signal processing circuit includes a CPU and a memory.
13. A cabinet for an MRI system according to claim 9, wherein the digital signal processing circuit includes a CPU and a memory.
14. A cabinet for an MRI system according to claim 10, wherein the digital signal processing circuit includes a CPU and a memory.
15. A cabinet for an MRI system according to claim 11, wherein the digital signal processing circuit includes a CPU and a memory.
16. A cabinet for an MRI system according to claim 1, including a power circuit as the electronic part of the water-cooled component.
17. A cabinet for an MRI system according to claim 2, including a power circuit as the electronic part of the water-cooled component.
18. A cabinet for an MRI system according to claim 3, including a power circuit as the electronic part of the water-cooled component.
19. A cabinet for an MRI system according to claim 5, including a power circuit as the electronic part of the water-cooled component.
20. A cabinet for an MRI system according to claim 16, wherein the power circuit includes an RF amplifier and a gradient amplifier.
Type: Application
Filed: Jun 14, 2007
Publication Date: Dec 20, 2007
Inventors: Tsunemoto Suzuki (Tokyo), Kengo Nakajima (Tokyo)
Application Number: 11/763,128
International Classification: F25D 23/12 (20060101);
