Magnetic resonance imaging system and method of operation of a magnetic resonance imaging system

Abstract

This invention provides a magnetic resonance imaging (MRI) system and a method for operating the MRI system that support user-defined settings such as the start of demagnetization of a superconducting magnet. The MRI apparatus includes: a superconducting magnet, including a superconducting coil cooled to a normal temperature for superconductivity; and a coil cooling device that cools the superconducting coil to the normal temperature through heat conduction caused by contact between a heat-conducting component cooled via a cold head and the superconducting coil. The processor of the MRI system calculates the operable time (excitation completion time) from the start of demagnetization of the superconducting magnet to the next time the MRI apparatus can start operating, based on the demagnetization start time of the superconducting magnet and the design values ​​of the MRI apparatus, and displays the excitation completion time on the operation screen (250-1) of the display to notify the operator.

Description

Technical Field

[0001] This invention relates to a magnetic resonance imaging system and a method for operating the magnetic resonance imaging system, and more particularly to a technology that supports user settings such as demagnetization start of the magnetic resonance imaging device. Background Technology

[0002] Conventional magnetic resonance imaging (MRI) devices include a coil cooling device that cools the superconducting magnet (the superconducting coil contained in the superconducting magnet) that functions as a magnet that generates a static magnetic field to a temperature at which it becomes superconducting.

[0003] Conventional coil cooling devices require cryogenic (4K Kelvin) liquid helium to cool superconducting coils (e.g., Patent Document 1).

[0004] In this type of MRI device, if the current supply to the superconducting coil is stopped during periods when the MRI device is not in use, the current flowing through the superconducting coil changes, causing the superconducting coil to heat up. However, due to the vaporization of liquid helium, the heating of the superconducting coil is suppressed, and it remains in a normal state. Thus, the MRI device can be restarted immediately, but there is the problem of requiring a large amount of precious and expensive helium.

[0005] In addition, if it is determined that it is necessary to stop supplying current to the superconducting coil of the MRI device to eliminate the magnetic field, it is necessary to request the dispatch of professional technicians, and the facility will need to spend time adjusting the standby time or work schedule.

[0006] Therefore, in recent years, there have also been MRI devices that can cool superconducting magnets without the need for liquid helium (e.g., Patent Document 2).

[0007] The MRI device described in Patent Document 2 includes a coil cooling device that houses a superconducting coil and has a liquid helium-free cooling container and multiple refrigerators for cooling the superconducting coil within the cooling container. The refrigerators are mounted on a spool on which the superconducting coil is wound, and the compressed refrigerant gas (such as helium or nitrogen) expands to generate cooling energy to directly cool the spool, thereby cooling the superconducting coil mounted on the spool.

[0008] As described in Patent Document 2, in the case of an MRI device that does not use a coil cooling device with liquid helium, since the cooling is directly achieved by connecting the refrigerator to the superconducting magnet (a spool of wire with a superconducting coil wound inside a cooling container), if the superconducting magnet of the MRI device is demagnetized from the energized state or energized after demagnetization, the temperature of the superconducting magnet (superconducting coil) will easily rise during the demagnetization or energization period.

[0009] Therefore, in order to prevent quenching caused by temperature rise, a device that does not use liquid helium has been developed. This device can automatically stop the current to the superconducting magnet (superconducting coil) and demagnetize the magnetic field without the need for professional maintenance technicians.

[0010] Patent Document 1: Japanese Patent Application Publication No. 2018-068775

[0011] Patent Document 2: Japanese Patent Application Publication No. 2013-144099

[0012] The superconducting magnets in MRI machines need to be in a superconducting cryogenic state during imaging. On the other hand, due to the high power consumption of MRI machines (or to ensure safety in high magnetic field environments or to cope with power outages), it may be considered to demagnetize the magnetic field and disconnect the power supply when the MRI machine is not in use. In this case, the timing of demagnetization needs to be determined based on the operator and the environment of the facility.

[0013] That is, after demagnetization, restarting the system in order to re-energize it requires not only the time needed to control the current of the superconducting magnet, but also the time needed to cool down the temperature rise caused by the current control, so it cannot be restarted immediately.

[0014] Demagnetization is required depending on when the system should be restarted. Summary of the Invention

[0015] The present invention was made in view of this situation, and its object is to provide a magnetic resonance imaging system and a method of operating the magnetic resonance imaging system that can support user settings such as the start of demagnetization of a superconducting magnet.

[0016] The invention involved in the first aspect is a magnetic resonance imaging system, which includes a magnetic resonance imaging device, a processor, and a user interface. The magnetic resonance imaging device includes: a superconducting magnet, including a superconducting coil cooled to a first temperature to become superconducting by a coil cooling device; and a coil cooling device that cools the superconducting coil by heat conduction caused by contact between a heat-conducting component cooled by a cold head and the superconducting coil to bring it to the first temperature. The processor performs the following processing: based on the demagnetization start time of the superconducting magnet and the design values ​​of the magnetic resonance imaging device, it obtains the operable time from the start of the demagnetization of the superconducting magnet to the next time the magnetic resonance imaging device can start operating; and notifies the operator of the operable time through the user interface.

[0017] According to the first aspect of the present invention, when the superconducting magnet is demagnetized, the operator can be notified of the next operable time when the magnetic resonance imaging device can be restarted. Thus, the operator can easily determine whether the timing of initiating the demagnetization of the superconducting magnet is suitable for the operable time of the magnetic resonance imaging device.

[0018] In the first embodiment, the magnetic resonance imaging system according to the second aspect of the present invention preferably includes the demagnetization time from the start to the completion of demagnetization of the superconducting magnet and the excitation time from the start to the completion of excitation of the superconducting magnet. The processor obtains the operable time by adding the demagnetization time and the excitation time to the start of demagnetization.

[0019] In the second aspect, the magnetic resonance imaging system according to the third aspect of the present invention preferably includes, if the demagnetization control corresponding to the demagnetization time and the excitation control corresponding to the excitation time are made continuous, then when the temperature of the superconducting coil exceeds a second temperature higher than the first temperature, the design value of the magnetic resonance imaging device also includes the pre-excitation waiting time from the completion of demagnetization of the superconducting magnet to the start of excitation of the superconducting magnet, and the processor obtains the operable time obtained by adding the demagnetization time, the pre-excitation waiting time and the excitation time to the start of demagnetization.

[0020] According to the second or third embodiment of the present invention, the operator can determine the operable time for the superconducting magnet to complete excitation after demagnetization, based on the time at which the demagnetization of the superconducting magnet begins, thereby determining whether it can be completed before the start time of the magnetic resonance imaging device.

[0021] In the first embodiment, the magnetic resonance imaging system according to the fourth aspect of the present invention preferably includes the design values ​​of the magnetic resonance imaging device including the demagnetization time from the start to the completion of demagnetization of the superconducting magnet, the excitation time from the start to the completion of excitation of the superconducting magnet, and the post-excitation cooling time from the completion of excitation of the superconducting magnet to the temperature of the superconducting coil returning to the first temperature. The processor obtains the operable time by adding the demagnetization time, excitation time, and post-excitation cooling time to the start of demagnetization.

[0022] Therefore, the operator can determine the operational time after the superconducting magnet is demagnetized and excitation is completed, and the temperature of the superconducting coil further recovers to the first temperature, based on the timing of starting the demagnetization of the superconducting magnet. This allows the operator to determine whether the operation can be completed before the start time of the magnetic resonance imaging device (the start time of the superconducting coil at the first temperature).

[0023] In the first embodiment, the magnetic resonance imaging system according to the fifth aspect of the present invention preferably includes the following design values ​​for the magnetic resonance imaging device: a demagnetization standby time from the start of demagnetization of the superconducting magnet as instructed by the operator to the start of demagnetization of the superconducting magnet; a demagnetization time from the start to the completion of demagnetization of the superconducting magnet; an excitation time from the start to the completion of excitation of the superconducting magnet; and a post-excitation cooling time from the completion of excitation of the superconducting magnet to the temperature of the superconducting coil returning to the first temperature. The processor obtains the operable time by adding the demagnetization standby time, demagnetization time, excitation time, and post-excitation cooling time to the start of demagnetization.

[0024] Therefore, when there is a demagnetization standby time from the start of demagnetization of the superconducting magnet to the start of demagnetization of the superconducting magnet, the operator can grasp the operable time after the superconducting magnet is demagnetized and the temperature of the superconducting coil returns to the first temperature, including the demagnetization standby time, so as to determine whether it can be completed before the start time of the magnetic resonance imaging device (the start time of the superconducting coil at the first temperature).

[0025] In any of the first to fifth embodiments of the magnetic resonance imaging system according to the sixth embodiment of the present invention, the processor preferably performs the following processing: acquiring the demagnetization start time and the demagnetization time from the start to the completion of demagnetization of the superconducting magnet; acquiring the demagnetization completion time obtained by adding the demagnetization time to the demagnetization start time; and notifying the operator of the demagnetization completion time via a user interface.

[0026] According to the sixth aspect of the present invention, upon receiving a demagnetization start command to demagnetize the superconducting magnet, in addition to informing the operator of the next operational time of the magnetic resonance imaging device, the operator can also be informed of the demagnetization completion time of the superconducting magnet. This allows the operator to determine the period without a magnetic field. For example, when it is necessary to bring a magnetic object into the examination room equipped with the magnetic resonance imaging device, the operator can determine the time when the magnetic object can be brought in.

[0027] In any of the first to fifth embodiments of the present invention, the magnetic resonance imaging system according to the seventh embodiment preferably includes a memory that stores a calculation formula or table containing design values ​​of the magnetic resonance imaging device, and the processor performs the following process: using the demagnetization start time and the calculation formula or table, at least the operable time is obtained.

[0028] In the seventh aspect, the magnetic resonance imaging system according to the eighth aspect of the present invention preferably performs the following processing: predicting the temperature of the superconducting coil in at least one of the following conditions: the excitation of the superconducting magnet is completed and the cooling after the excitation of the superconducting magnet is completed, and notifying the operator of the predicted temperature via a user interface.

[0029] In any of the first to eighth embodiments of the magnetic resonance imaging system according to the ninth embodiment of the present invention, the processor preferably performs the following processing: receiving a schedule including the demagnetization start time and excitation start time of the superconducting magnet set by the user; and notifying the operator of the schedule via the user interface.

[0030] The operator can determine the schedule for the start times of demagnetization and excitation of the superconducting magnet, as well as the operational time at which the MRI scanner can be restarted. Therefore, if the operational time of the MRI scanner is later than the actual restart time, the operator can adjust the schedule appropriately to ensure that the operational time is earlier than the actual start time of imaging.

[0031] In the 9th aspect, the magnetic resonance imaging system according to the 10th aspect of the present invention preferably includes the start time of operation of the magnetic resonance imaging device in the schedule. The processor performs the following processing: checks whether the start time of operation is earlier than the time when it can be operated; and if the start time of operation is earlier than the time when it can be operated, notifies the operator of the conflicting start time of operation via the user interface, or instructs the schedule to be corrected.

[0032] The magnetic resonance imaging system according to the 11th aspect of the present invention preferably includes a temperature sensor for detecting the temperature of a superconducting magnet or a superconducting coil in any of the 1st to 10th aspects, and the processor notifies the operator of the temperature detected by the temperature sensor at each moment via a user interface.

[0033] In any of the first to eleventh embodiments of the present invention, the magnetic resonance imaging system according to the 12th embodiment preferably has a user interface with a consultation button for contacting a professional technician of the supplier of the magnetic resonance imaging device, and the processor performs the following processing: when the consultation button is operated, it is able to contact the professional technician and notify the supplier of the information that was notified to the operator via the user interface.

[0034] It allows operators to share information with the supplier's technical staff, contact them via a consultation button, and obtain advice as needed. Even if the MRI machine is out of service for several days, it can be operated without the need for technical staff, reducing hassle and time.

[0035] In any of the first to twelfth embodiments of the present invention, the magnetic resonance imaging system according to the 13th embodiment preferably has a user interface that can automatically notify the supplier of the magnetic resonance imaging device, and the processor performs the following processing: according to the operation of the operation button, the information that was notified to the operator via the user interface is notified to the supplier.

[0036] In any of the first to thirteenth embodiments of the present invention, the processor preferably performs the following processing: after the superconducting magnet is demagnetized, the temperature of the superconducting magnet is reduced by a coil cooling device and then the temperature rises by excitation and exceeds a temperature threshold; or after the excitation of the superconducting magnet is completed, the temperature of the superconducting magnet is reduced by a coil cooling device and falls below a temperature threshold. In at least one of these cases, the information that is supposed to be given to the operator via a user interface is notified to the supplier of the magnetic resonance imaging device.

[0037] In the 13th embodiment of the magnetic resonance imaging system according to the 15th embodiment of the present invention, the preferred operation button is an automatic notification start button, and the processor performs the following processing: in at least one of the following situations, the automatic notification start button is set to start, and after the demagnetization of the superconducting magnet is completed, the temperature of the superconducting magnet is reduced by the coil cooling device and then the temperature rises by excitation and exceeds the temperature threshold, and after the excitation of the superconducting magnet is completed, the temperature of the superconducting magnet is reduced by the coil cooling device and falls below the temperature threshold, the information that is supposed to be notified to the operator via the user interface is notified to the supplier of the magnetic resonance imaging device.

[0038] If the temperature of the superconducting magnet decreases, and then rises due to excitation, exceeding the temperature threshold, the temperature rise caused by demagnetization is defined as the first temperature rise, and the temperature rise caused by excitation is defined as the second temperature rise. If the temperature of the superconducting magnet exceeds the temperature threshold due to this second temperature rise, normal recovery operation begins, and the information intended for the operator is communicated to the supplier at this time. Similarly, if the excitation of the superconducting magnet is completed, and the temperature of the superconducting magnet decreases below the temperature threshold due to the coil cooling device, the temperature decrease caused by cooling after demagnetization is defined as the first temperature decrease, and the temperature decrease caused by cooling after excitation is defined as the second temperature decrease. If the temperature of the superconducting magnet falls below the temperature threshold due to this second temperature decrease, complete recovery towards the first temperature is initiated, and the information intended for the operator is communicated to the supplier at this time.

[0039] In the 13th embodiment, the magnetic resonance imaging system according to the 16th embodiment of the present invention preferably has an operation button that saves a schedule including the demagnetization start time and excitation start time of the superconducting magnet set by the user. When the user interface operates the save button, the schedule is saved in the memory, and the information that is notified to the operator through the user interface is notified to the supplier of the magnetic resonance imaging device.

[0040] The invention involved in the 17th aspect is a method of operating a magnetic resonance imaging system, the magnetic resonance imaging system comprising a magnetic resonance imaging device, a processor, and a user interface, the magnetic resonance imaging device comprising: a superconducting magnet including a superconducting coil cooled to a first temperature to become superconducting; and a coil cooling device that cools the superconducting coil by heat conduction caused by contact between a heat-conducting component cooled via a cold head and the superconducting coil to bring it to the first temperature, the method of operating the magnetic resonance imaging system comprising the following steps: the processor obtaining, based on the demagnetization start time of the superconducting magnet and the design values ​​of the magnetic resonance imaging device, the operable time from the start of demagnetization of the superconducting magnet to the next time the magnetic resonance imaging device can start operating; and the processor notifying the operator of the operable time via the user interface.

[0041] The method of operating the magnetic resonance imaging system according to the 18th aspect of the present invention, in the 17th aspect, preferably includes the following steps: the processor acquires the demagnetization start time and the demagnetization time from the start to the completion of the demagnetization of the superconducting magnet; the processor acquires the demagnetization completion time obtained by adding the demagnetization time to the demagnetization start time; and the processor notifies the operator of the demagnetization completion time via a user interface.

[0042] Invention Effects

[0043] According to the present invention, the operable time for the next restart of the magnetic resonance imaging device can be obtained based on the demagnetization start time of the superconducting magnet, and the operable time can be notified to the operator, thereby supporting user settings such as the start of demagnetization of the superconducting magnet. Attached Figure Description

[0044] Figure 1 This is a perspective view showing the appearance of a magnetic resonance imaging apparatus (MRI apparatus) applicable to the magnetic resonance imaging system involved in this invention.

[0045] Figure 2 This is a diagram showing the schematic internal structure of the magnetic resonance imaging system involved in this invention.

[0046] Figure 3 It means Figure 1 A diagram showing the cross-sectional structure of the magnet in the MRI device.

[0047] Figure 4 This is a diagram showing the interior of the operating room where the MRI equipment is operated.

[0048] Figure 5 This is a diagram illustrating a first embodiment of the magnetic resonance imaging system according to the present invention, and in particular, a diagram illustrating the operation screen of the display.

[0049] Figure 6This is a timing diagram used to illustrate the calculation method of Mode 1.

[0050] Figure 7 This is a timing diagram used to illustrate the calculation method of the second mode.

[0051] Figure 8 This is a diagram illustrating a second embodiment of the magnetic resonance imaging system according to the present invention, and in particular, a diagram illustrating the operation screen of the display.

[0052] Figure 9 This is a timing diagram showing the state of each part of the MRI apparatus in the second embodiment of the magnetic resonance imaging system according to the present invention.

[0053] Figure 10 It is a timing diagram used to illustrate the definition of each moment and time in the method of calculating time.

[0054] Figure 11 This is a graph showing an example of the temperature change curve when cooling from the critical temperature Tc.

[0055] Figure 12 It is a graph representing the function Δf(temp0, Δtime) that gives the temperature change after time Δtime from the initial temperature temp0.

[0056] Figure 13 This is a timing diagram showing the state of each part of the MRI apparatus in the third embodiment of the magnetic resonance imaging system according to the present invention.

[0057] Figure 14 This is a diagram illustrating a third embodiment of the magnetic resonance imaging system according to the present invention, and in particular, a diagram illustrating the operation screen of the display.

[0058] Figure 15 This is a timing diagram showing the state of each part of the MRI apparatus in the fourth embodiment of the magnetic resonance imaging system according to the present invention.

[0059] Figure 16 This is a schematic diagram illustrating the fifth embodiment of the magnetic resonance imaging system according to the present invention.

[0060] Figure 17 This is a graph illustrating an example of how coil temperature changes with time-controlled demagnetization / excitation.

[0061] Figure 18 This is a flowchart illustrating an embodiment of the working method of the magnetic resonance imaging system involved in this invention.

[0062] Symbol Explanation

[0063] 10- Magnetic Resonance Imaging system, 100- MRI apparatus, 102- Subject, 104- Magnet, 106- Gradient magnetic field coil, 107- Cold head, 108- Transmission coil, 110- Reception coil, 112- High-frequency magnetic field generator, 114- Gradient magnetic field power supply, 116- Receiver, 118- Timing controller, 120- Imaging space, 130- Bed table, 130A- Top plate, 200- Control device, 202- Processor, 204- Memory, 206- Input / output interface, 208, 300- Display, 210- Operation unit, 220- Operator, 230- Superconducting coil, 232- Vacuum vessel, 232a- Outer vessel, 232b- Inner vessel, 234- Radiation heat shielding plate, 236- Thermally conductive member, 238- Temperature sensor, 242, 246, 251, 252, 253- Display column, 244- "Start" button, 250-1, 250-2, 250-3, 250-5- Operation screen, 254- Radio button, 256, 257- List box, 258, 259- Input field, 260- Save button, 270- Coil temperature display unit, 271- Consultation button, 272- Automatic notification enable button, 310- Skilled technician. Detailed Description of the Preferred Embodiments

[0064] Hereinafter, preferred embodiments of the magnetic resonance imaging system and the operating method of the magnetic resonance imaging system according to the present invention will be described with reference to the accompanying drawings.

[0065] [External Appearance of MRI Apparatus]

[0066] Figure 1 is a perspective view showing the external appearance of a magnetic resonance imaging apparatus (MRI apparatus) applicable to the magnetic resonance imaging system according to the present invention.

[0067] Figure 1 The illustrated MRI apparatus 100 is provided with a magnet 104 that generates a static magnetic field, and a bed table 130 that includes a top plate 130A disposed on the front side of an imaging space 120 formed in the cylindrical portion of the magnet 104.

[0068] [Internal Structure of Magnetic Resonance Imaging System]

[0069] Figure 2 is a diagram showing the schematic internal structure of the magnetic resonance imaging system according to the present invention.

[0070] As shown in Figure 2 , the magnetic resonance imaging system 10 is constituted by an MRI apparatus 100 and a control device 200.

[0071] <MRI Apparatus>

[0072] The MRI device 100 includes: a magnet 104 that generates a uniform static magnetic field in an imaging space 120 in which the subject 102 is disposed; a gradient magnetic field coil 106 that generates a gradient magnetic field in the imaging space 120; an RF (Radio Frequency) coil (transmitting coil) 108 that generates a high-frequency magnetic field that causes the atomic nuclei of the atoms constituting the tissue of the subject 102 to generate nuclear magnetic resonance signals (NMR signals); and a receiving coil 110 that detects the NMR signals generated from the subject 102.

[0073] The subject 102 is typically positioned in the imaging space 120 lying on the top plate 130A of the bed 130. The receiving coil 110 uses a receiving coil corresponding to the examination site of the subject 102 and is positioned on the subject 102 on the bed 130.

[0074] The timing controller 118 sends control information to the high-frequency magnetic field generator 112 and the gradient magnetic field power supply 114 according to the imaging sequence, thereby controlling the acquisition of NMR signals based on the receiver 116.

[0075] The high-frequency magnetic field generator 112 generates a high-frequency current pulse at the Larmor frequency that induces nuclear magnetic resonance based on control information input from the timing controller 118, and sends it to the transmitting coil 108. An RF pulse corresponding to this high-frequency current pulse is then transmitted from the transmitting coil 108 to the subject 102.

[0076] The receiving coil 110 detects the NMR signal generated by the excitation of the atomic nuclei spin within the subject 102 by an RF pulse, amplifies the detected NMR signal, and transmits it to the control device 200 via the receiver 116. NMR signals are typically generated by gradient echo or spin echo and imaging sequence (pulse sequence), and the generated signal is called an echo signal.

[0077] Figure 1 The receiving coil 110 shown receives echo signals from the head of the subject 102, but is not limited to receiving echo signals from the head. Receiving coils corresponding to examination sites of the subject 102, such as the chest, abdomen, waist, shoulders, hands, and feet, can also be used and appropriately configured. Furthermore, the receiving coil also includes a soft, blanket-type receiving coil that covers the chest, abdomen, and waist.

[0078] The gradient magnetic field coil 106 is composed of an X-axis gradient magnetic field coil, a Y-axis gradient magnetic field coil, and a Z-axis gradient magnetic field coil that generate gradient magnetic fields Gx, Gy, and Gz in the X-axis, Y-axis, and Z-axis directions of the imaging space 120, respectively, and generates a gradient magnetic field in the imaging space 120 corresponding to the current supplied from the gradient magnetic field power supply 114.

[0079] The timing controller 118 controls each component to operate at pre-programmed times and intensities. In particular, the part of the program that records the RF pulse, gradient magnetic field Gx, Gy, Gz, and the time or intensity of signal reception is called the imaging sequence (pulse sequence).

[0080] Various pulse sequences are known depending on the purpose, but their detailed descriptions are omitted here.

[0081] <Magnet and Coil Cooling Device>

[0082] The magnet 104 that generates a static magnetic field can be either a magnet that generates a static magnetic field in the vertical direction or a magnet that generates a static magnetic field in the horizontal direction, but we will take a magnet that generates a static magnetic field in the horizontal direction as an example for explanation.

[0083] Figure 3 It means Figure 1 A diagram showing the cross-sectional structure of the magnet 104 of the MRI device.

[0084] like Figure 3 As shown, the magnet 104 uses a superconducting coil 230 wound into a cylindrical shape to generate a static magnetic field in the horizontal direction (the direction of the body axis of the subject 102). The superconducting coil 230 wound into a cylindrical shape is disposed inside a cylindrical vacuum container 232.

[0085] The vacuum container 232 has a dual structure consisting of an outer container 232a and an inner container 232b. The space between the outer container 232a and the inner container 232b is evacuated to a specified pressure and equipped with a radiative heat shield 234. A superconducting coil 230 is disposed inside the inner container 232b.

[0086] The space within the inner container 232b, where the superconducting coil 230 is disposed, is evacuated to a specified pressure. The imaging space 120 for the subject 102 is formed in the space near the central axis of the vacuum container 232.

[0087] The vacuum container 232 includes a cold head 107, the front end of which is inserted into the interior of the inner container 232b of the vacuum container 232. A compressor (not shown) is connected to the cold head 107, from which compressed refrigerant gas is supplied. The cold head 107, the compressor, and the like constitute a coil cooling device (cryogenic cooler) for cooling the superconducting coil 230 (magnet 104).

[0088] The cold head 107 generates a cooling effect through the adiabatic expansion of the refrigerant gas inside, thereby cooling the front end of the cold head 107. A highly thermally conductive heat-conducting component 236 is disposed between the front end of the cold head 107 and the superconducting coil 230, with one end of the heat-conducting component 236 connected to the cold head 107 and the other end connected to the superconducting coil 230. Thus, the coil cooling device cools the superconducting coil 230 by the heat conduction caused by the contact between the heat-conducting component 236 cooled by the cold head 107 and the superconducting coil 230, so that it reaches a normal temperature (hereinafter referred to as "normal temperature") such as the first superconducting temperature (e.g., 4K).

[0089] Furthermore, a portion of the cold head 107 is connected to the radiative heat shield 234 of the vacuum container 232 and the inner container 232b, and cools these.

[0090] In this way, the coil cooling device maintains the thermal equilibrium state of the magnet 104, thereby realizing a closed superconducting magnet. That is, the cooling capacity is controlled to cool the heat that invades the vacuum container 232 without being excessive or insufficient.

[0091] Furthermore, multiple temperature sensors 238 for monitoring the operating status are assembled in the magnet 104.

[0092] The vacuum container 232, which serves as the cooling container, is helium-saving. Here, helium saving means that the cooling container is in a state where there is no liquid helium or gaseous helium, or a state where gaseous helium is present but liquid helium is absent, or a state where the superconducting coil 230 is cooled by heat conduction from the heat-conducting component 236 that is in contact with the cold head 107, or a state where helium does not contact the superconducting coil 230, or a state where liquid helium and / or gaseous helium are present in the cooling container.

[0093] That is, the MRI device 100 to which the present invention is applied has a helium-saving coil cooling device.

[0094] Furthermore, in the case of a helium-saving coil cooling device, since there is no liquid helium in the cooling container, if the magnet 104 of the MRI device 100 is demagnetized from the energized state or energized after demagnetization, the heat generated by the superconducting coil 230 exceeds the cooling capacity of the helium-saving coil cooling device due to the change in the coil current flowing through the superconducting coil 230 during the demagnetization or energization period. Therefore, the temperature of the superconducting coil 230 (magnet 104) easily rises from the normal superconducting temperature.

[0095] That is, the magnet 104 of the superconducting coil of the MRI device 100 is cooled by a helium-saving coil cooling device, but the temperature of the superconducting coil 230 rises from the normal temperature according to the change of coil current during the demagnetization and excitation periods of the magnet 104.

[0096] <Control Device>

[0097] The control device 200, as hardware, includes a processor 202, a memory 204, an input / output interface 206, a display 208, and an operation unit 210.

[0098] The processor 202 is composed of a CPU (Central Processing Unit), which centrally controls all parts within the control device 200 and controls the operation of the MRI device 100 via the timing controller 118. It receives digital data (measurement data) of the echo signal through the receiver 116 and performs various signal processing such as image reconstruction.

[0099] Furthermore, the processor 202 receives a demagnetization start command to demagnetize the magnet 104 of the MRI device 100. If the demagnetization start time is reached, the demagnetization of the magnet 104 of the MRI device 100 is started. It also receives an excitation start command to excite the magnet 104. If the excitation start time is reached, the excitation of the magnet 104 is started.

[0100] Furthermore, if the processor 202 receives a degaussing start command, it notifies the operational time from the start of degaussing of the MRI device 100 to the next time the MRI device 100 can start operating, and also notifies the degaussing completion time of the MRI device 100, thereby supporting user settings for the start of degaussing and excitation of the MRI device 100. Details regarding the processing of supporting user settings for the start of degaussing and excitation will be described later.

[0101] The memory 204 includes flash memory, ROM (Read-only Memory), RAM (Random Access Memory), hard disk drive, etc. The flash memory, ROM, or hard disk drive is a non-volatile memory that stores the operating system, the program that enables the processor 202 to function as the control device 200 of the MRI apparatus 100, the calculation formulas or tables required for calculating the demagnetization completion time, excitation completion time, and cooling completion time of the magnet 104 (described later), and the design values ​​of the MRI apparatus 100, etc.

[0102] RAM functions as the working area for the processor 202 and temporarily stores programs stored in non-volatile memory. Alternatively, the processor 202 may also incorporate a portion of the memory 204 (RAM).

[0103] The input / output interface 206 includes a communication unit capable of connecting to a network and a connection unit capable of connecting to external devices. As the connection unit capable of connecting to external devices, USB (Universal Serial Bus) and HDMI (High-Definition Multimedia Interface) (HDMI is a registered trademark) can be used.

[0104] The processor 202 communicates with the devices (in this example, the timing controller 118 and the receiver 116) located in the MRI apparatus 100 via the input / output interface 206, thereby transmitting and receiving the required information. In addition, a portion of the timing controller 118 may be located on the control device 200 side.

[0105] The display 208 serves as part of the user interface for displaying MRI images and displaying operation screens when receiving input from the operation unit 210. Furthermore, in the manual setting of the schedule of the MRI device 100, which includes the start of demagnetization and the start of excitation, if there is a conflict between the time of completion of demagnetization and excitation of the MRI device 100 and the schedule, the display 208 notifies the operator of a warning or instructs the operator to correct the schedule.

[0106] The operation unit 210 includes a mouse, keyboard, etc., and uses the operation screen of the display 208 to function as part of the user interface for receiving input from the operator.

[0107] [Implementation of Magnetic Resonance Imaging Systems]

[0108] Figure 4 This is a diagram showing the interior of the operating room where the MRI equipment is operated.

[0109] like Figure 4 As shown, a control device 200 (reference) is installed in the control room. Figure 2 The control device 200 controls the MRI device 100 located in the examination room and processes the echo signals output from the MRI device 100 to generate MRI images.

[0110] Operator 220 can use keyboard, mouse and other operating units 210 ( Figure 2 The MRI device 100 is controlled by the control device 200 via the display 208 and the control device 200.

[0111] In addition, Figure 4 In the control room, there is a window for the operator 220 to observe the situation in the inspection room.

[0112] <First Implementation>

[0113] Figure 5This is a diagram illustrating a first embodiment of the magnetic resonance imaging system according to the present invention, and in particular, a diagram illustrating the operation screen of the display.

[0114] When demagnetizing the magnet 104 of the MRI device 100 is initiated, the operator 220 may request confirmation of the time at which the MRI device 100 can start operating next (e.g., the excitation completion time when re-excitation is performed after demagnetization).

[0115] Figure 5 The operation screen 250-1 shown, in the case of starting the demagnetization of the magnet 104, is a screen used to confirm the excitation completion time of the next excitation. For example, it can be accessed by... Figure 4 The operation screen of the display 208 shown displays the "Off" button used to demagnetize the magnet 104.

[0116] exist Figure 5 The operation screen 250-1 shown includes: a display bar 242, which indicates the current status of the magnetic field of the MRI device 100 (magnetic field on / off); a "Start" button 244, which starts demagnetization; and a display bar 246, which, when demagnetization has started, displays the next time when the MRI device 100 can start operating (in this example, the excitation completion time).

[0117] The processor 202 obtains the operable time (e.g., the excitation completion time) from the start of demagnetization to the next time the MRI device 100 can start operating by adding the demagnetization time and the excitation time at the start of demagnetization, and displays the obtained excitation completion time in the display bar 246 of the operation screen 250-1.

[0118] In addition, the demagnetization time and excitation time can be stored in memory 204 as design values ​​of the MRI device 100 in advance, and the processor 202 can read them from memory 204 and use them as needed.

[0119] Furthermore, the user operation start time before pressing the "Start" button 244 is the current time, which changes constantly. The excitation completion time is obtained by the processor 202 based on the constantly changing user operation start time and displayed in the display bar 246. The display bar 246 can be updated in seconds or at regular intervals such as minutes. When the "Start" button 244 is pressed, the operation time is fixed as the user operation start time, and the excitation completion time of the MRI device 100 is displayed in the display bar 246.

[0120] Calculation Method for Excitation Completion Time

[0121] Next, the calculation method for the excitation completion time will be explained.

[0122] There are two methods for calculating the excitation completion time: Mode 1 and Mode 2.

[0123] (Calculation method for mode 1)

[0124] The calculation method for Mode 1 is the same as the calculation method for the case where excitation can be performed immediately after demagnetization. Figure 6 This is a timing diagram used to illustrate the calculation method of Mode 1.

[0125] like Figure 6 As shown, the calculation method for the first mode is the calculation method for the case where the temperature of the superconducting coil will not exceed the second temperature (critical temperature Tc in this example) which is higher than the normal temperature (first temperature) even if it is immediately energized after demagnetization. The calculation method can be used to calculate each time and temperature using the following formula.

[0126] [Formula 1]

[0127] Demagnetization completion time = Demagnetization start time + Demagnetization time

[0128] = User operation start time + Standby time + Demagnetization time

[0129] [Formula 2]

[0130] Excitation completion time = Demagnetization completion time + Excitation time

[0131] [Formula 3]

[0132] Excitation post-cooling completion time = Excitation completion time + Excitation post-cooling time

[0133] [Formula 4]

[0134] Temperature immediately after excitation = Temperature before demagnetization (current temperature) + Temperature rise caused by demagnetization + Temperature rise caused by excitation

[0135] [Formula 5]

[0136] Temperature after cooling is complete = Temperature before demagnetization (current temperature)

[0137] (Calculation method for mode 2)

[0138] Regarding the calculation method for the second mode, if the demagnetization control corresponding to the demagnetization time and the excitation control corresponding to the excitation time are continuous, then it is the calculation method corresponding to the case where the temperature of the superconducting coil exceeds the critical temperature Tc (i.e., the case where a waiting time before excitation is generated after demagnetization in a manner that does not exceed the critical temperature Tc). Figure 7 This is a timing diagram used to illustrate the calculation method of the second mode.

[0139] If re-energization occurs immediately after demagnetization, the temperature of magnet 104 (superconducting coil) may sometimes exceed the critical temperature Tc due to the combined temperature rise caused by demagnetization and re-energization. In this case, if... Figure 7 As shown in (C), in order to ensure that the temperature of the superconducting coil does not exceed the critical temperature Tc, during the period from the completion of demagnetization to the start of excitation, as follows: Figure 7 As shown in (B), the magnetic field needs to be set to the off time (i.e., the pre-excitation waiting time before excitation begins).

[0140] The calculation method for the second mode is the same as the calculation method for the waiting time before excitation, which can be used to calculate each moment and temperature using the following formula.

[0141] [Formula 1]

[0142] Demagnetization completion time = Demagnetization start time + Demagnetization time

[0143] = User operation start time + Standby time + Demagnetization time

[0144] [Formula 2']

[0145] Excitation completion time = Demagnetization completion time + Waiting time before excitation + Excitation time

[0146] [Formula 3]

[0147] Excitation post-cooling completion time = Excitation completion time + Excitation post-cooling time

[0148] [Formula 4']

[0149] The temperature immediately after excitation is completed = critical temperature Tc

[0150] [Formula 5]

[0151] Temperature after cooling is complete = Temperature before demagnetization (current temperature)

[0152] Here, the pre-excitation waiting time in [Equation 2'] is the solution to the following equation.

[0153] [Formula 6]

[0154] Critical temperature Tc - (temperature immediately after demagnetization + Δf (temperature immediately after demagnetization, waiting time before excitation)) = temperature rise caused by excitation

[0155] Furthermore, the post-excitation cooling time in [Equation 3] is the solution to the following equation.

[0156] [Formula 7]

[0157] Critical temperature Tc + Δf (critical temperature Tc, cooling time after excitation) = temperature before demagnetization (current temperature)

[0158] Where Δf represents the state when the superconducting coil stops heating, as described later. Figure 12 As shown, this represents the temperature change of a superconducting coil as it decreases from an initial temperature temp0 to a normal temperature by a coil cooling device, using the initial temperature (temp0) and cooling time (time) as parameters.

[0159] The definitions of each moment and time in [Equation 1] to [Equation 5] above are as follows.

[0160] • Demagnetization start time: The actual time when demagnetization begins (the time when the user operation starts plus the demagnetization standby time, or the time when the user operation starts if there is no demagnetization standby time).

[0161] • User operation start time: The moment when the user indicates demagnetization via the demagnetization start button, etc.

[0162] • Demagnetization standby time: Preparation time for demagnetization of 100 pairs of MRI devices

[0163] • Demagnetization time: The time required for the magnetic field to be present (on) and for it to disappear (off) from the present state (static magnetic field).

[0164] • Pre-excitation waiting time: The time from the completion of demagnetization to the start of excitation.

[0165] • Demagnetization completion time: The moment when the magnetic field (static magnetic field) disappears.

[0166] • Excitation time: The time required to change from a state without a magnetic field (off) to a state with a magnetic field (on).

[0167] • Post-excitation cooling time: The time it takes for the temperature to rise due to excitation and then return to normal operating temperature through cooling.

[0168] According to the first embodiment, in the case of the MRI device corresponding to the first mode, the operable time (excitation completion time) obtained by adding the demagnetization time and the excitation time to the demagnetization start time can be obtained, and the excitation completion time can be displayed in the display bar 246 of the operation screen 250-1. In the case of the MRI device corresponding to the second mode, the operable time (excitation completion time) obtained by adding the demagnetization time, the pre-excitation waiting time and the excitation time to the demagnetization start time can be obtained, and the excitation completion time can be displayed in the display bar 246 of the operation screen 250-1.

[0169] Alternatively, the excitation completion time can be displayed on operation screen 250-1 instead of the excitation completion time, or both the excitation completion time and the excitation cooling completion time can be displayed on operation screen 250-1. The excitation cooling completion time can be calculated by adding the excitation cooling time to the excitation completion time.

[0170] Furthermore, in the case of an MRI device corresponding to the first mode, the processor 202 can calculate the temperature immediately after excitation and the temperature after cooling after excitation using the aforementioned [Equation 4] and [Equation 5], respectively, and display them on the display 208. In the case of an MRI device corresponding to the second mode, the processor 202 can calculate the temperature immediately after excitation and the temperature after cooling after excitation using the aforementioned [Equation 4'] and [Equation 5], respectively, and display them on the display 208.

[0171] <Second Implementation Method>

[0172] Figure 8 This is a diagram illustrating a second embodiment of the magnetic resonance imaging system according to the present invention, and in particular, a diagram illustrating the operation screen of the display.

[0173] In situations where it is necessary to bring magnetic objects into the examination room, hospital staff may request that the magnetic field of the MRI machine be reduced.

[0174] Therefore, the processor 202 of the control device 200 uses Figure 8 The operation screen 250-2 of the display 208 shown can receive the demagnetization start time from the operator 220, and start the demagnetization of the magnet 104 of the MRI device 100 from the demagnetization start time, calculate the time when the demagnetization of the magnet 104 is completed, and display the demagnetization completion time on the operation screen 250-2.

[0175] Thus, operator 220 can confirm the time period during which the magnetic object is safely brought into the inspection room.

[0176] In addition, Figure 8 In the diagram, symbol 251 is the display bar that shows the demagnetization completion time, and symbols 252 and 253 are the display bars that show the excitation completion time (predicted temperature) and the cooling completion time (predicted temperature) after excitation and cooling to normal temperature, respectively.

[0177] Ideally, imaging based on the MRI device 100 should be performed after the magnet 104 has been fully cooled to its normal temperature. However, imaging can be performed as soon as excitation is completed. Therefore, the excitation completion time and the cooling completion time can be monitored in display bar 252 and display bar 253.

[0178] Furthermore, symbol 254 is a radio button for enabling the setting of the excitation start date and time and the demagnetization start date and time, respectively; symbols 256 and 257 are list boxes for setting the demagnetization start date and the excitation start date, respectively. Moreover, symbols 258 and 259 are input fields for receiving the demagnetization start time (moment) of the demagnetization start date and the excitation start time (moment), respectively.

[0179] Furthermore, the user can use the operation screen 250-2 to set the demagnetization start date and time and the excitation start date and time. Symbol 260 is the "Save Button" for saving the user-set schedule, and symbol 261 is the "Cancel Button" for canceling the saved schedule.

[0180] Figure 9 This is a timing diagram showing the state of each part of the MRI apparatus in the second embodiment of the magnetic resonance imaging system according to the present invention.

[0181] Figure 9 (A) is a timing diagram showing the state of an MRI examination based on the MRI device 100, illustrating the period during the examination (examination period) and the period during which a magnetic object can be introduced.

[0182] like Figure 9 As shown in (B), the coil cooling device of the MRI device 100 is always in the on state.

[0183] like Figure 9 As shown in (C), during an examination based on the MRI device 100 (during the examination period), the magnetic field of the magnet 104 is turned on, and during the period when a magnetic object can be introduced, the magnetic field of the magnet 104 is turned off.

[0184] exist Figure 9 In the example shown, demagnetization begins at 11 o'clock, and the magnetic field in the on state gradually decreases from 11 o'clock until the magnetic field is turned off.

[0185] Figure 9 (D) is a graph showing the time-varying temperature of the superconducting coil 230 contained in the magnet 104.

[0186] like Figure 9 As shown in (D), the temperature of the coil at normal operating temperature begins to rise due to demagnetization at 11 o'clock. This is because the current flowing through the superconducting coil 230 changes due to demagnetization, and the heat generated by the superconducting coil 230 exceeds the cooling capacity per unit time based on the coil cooling device.

[0187] If the demagnetization of magnet 104 is completed (excitation becomes off), then a magnetic material can be introduced.

[0188] In the second embodiment, the processor 202 calculates the demagnetization completion time of the magnet 104 and displays the demagnetization completion time in the display bar 251 of the operation screen 250-2. Thus, the operator 220 can know the demagnetization completion time.

[0189] Once the demagnetization of magnet 104 is complete, the current flowing through superconducting coil 230 becomes zero, and the heating of the superconducting coil stops. On the other hand, the coil cooling device remains on, so the temperature of the superconducting coil 230 (magnet 104), which rose due to demagnetization, gradually decreases and returns to its normal temperature.

[0190] If the magnetic object brought into the examination room is removed and the examination based on the MRI device 100 is started, the processor 202 starts the excitation of the magnet 104 according to the excitation start instruction.

[0191] If the magnet 104 is energized (if current flows through the superconducting coil 230), the coil temperature, which has dropped to normal temperature, rises due to the energization. This is because the current flowing through the superconducting coil 230 changes due to the energization, and the heat generated by the superconducting coil 230 exceeds the cooling capacity per unit time based on the coil cooling device.

[0192] If the magnet 104 is energized (energization is turned on), the current flowing through the superconducting coil 230 becomes constant, and the heating of the superconducting coil 230 stops. On the other hand, the coil cooling device is always turned on, so the temperature of the superconducting coil 230 (magnet 104) that rose due to energization gradually decreases and returns to normal temperature.

[0193] The processor 202 predicts the excitation completion time of the magnet 104 and displays the excitation completion time in the display bar 252 of the operation screen 250-2. After the excitation is completed, it predicts the cooling completion time when the temperature returns to normal and displays the cooling completion time in the display bar 253 of the operation screen 250-2.

[0194] Furthermore, the coil temperatures at the excitation completion time and cooling completion time are predicted and displayed in display columns 252 and 253, respectively.

[0195] Figure 10 It is a timing diagram used to illustrate the definition of each moment and time in the method of calculating time.

[0196] like Figure 10 As shown, the definitions of each moment and time in the above calculation method are as follows.

[0197] • Demagnetization start time: The actual time when demagnetization begins (the time when the user operation starts plus the demagnetization standby time, or the time when the user operation starts if there is no demagnetization standby time).

[0198] • User operation start time: The moment when the user indicates demagnetization via the demagnetization start button, etc.

[0199] • Demagnetization standby time: Preparation time for demagnetization of 100 pairs of MRI devices

[0200] • Demagnetization time: The time required for the magnetic field to be present (on) and for it to disappear (off) from the present state (static magnetic field).

[0201] The demagnetization time is stored in memory 204 as a design value for the MRI device 100.

[0202] Demagnetization completion time: The moment when the magnetic field (static magnetic field) disappears.

[0203] The processor 202 can read the demagnetization time from the memory 204 and calculate the demagnetization completion time using the aforementioned [Equation 1].

[0204] Furthermore, in [Equation 1], in the case of an MRI device that does not require a demagnetization standby time, the demagnetization completion time can be determined by setting the demagnetization standby time to zero.

[0205] • Cooling time after demagnetization: The time it takes for the temperature to return to normal after the temperature rises due to demagnetization and through cooling.

[0206] • Cooling completion time after demagnetization: The moment when the temperature returns to normal after the temperature rises due to demagnetization and then cools down.

[0207] The cooling time after demagnetization is stored in memory 204 as a design value for the MRI device 100.

[0208] The processor 202 reads the demagnetization cooling time from the memory 204 and calculates the cooling completion time after demagnetization using the following formula.

[0209] [Formula 8]

[0210] Demagnetization completion time = Demagnetization completion time + Demagnetization cooling time

[0211] The following definitions of each moment and time in excitation are based on the definitions of demagnetization and excitation as described above.

[0212] • Excitation start time: The time when the user indicates excitation via the excitation start button, etc.

[0213] • Excitation time: The time required to change from a state without a magnetic field (off) to a state with a magnetic field (on).

[0214] The excitation time is stored in memory 204 as a design value for the MRI device 100.

[0215] • Post-excitation cooling time: The time it takes for the temperature to rise due to excitation and then return to normal operating temperature through cooling.

[0216] • Post-excitation cooling completion time: The time when the temperature returns to normal after rising due to excitation and cooling.

[0217] The post-excitation cooling time is stored in memory 204 as a design value of the MRI device 100, or it is calculated based on the temperature change information stored in memory 204.

[0218] The processor 202 can read the post-excitation cooling time from the memory 204, or calculate the post-excitation cooling time based on the temperature change information stored in the memory 204, and calculate the post-excitation cooling completion time using the aforementioned [Equation 3].

[0219] Next, the method for predicting the temperature change of magnet 104 (superconducting coil) will be explained.

[0220] In order to predict the temperature change of magnet 104, the following information is stored in memory 204.

[0221] • Temperature rise caused by demagnetization: The temperature rise from normal temperature during the demagnetization period.

[0222] • Temperature rise caused by excitation: The temperature rise from normal temperature during the excitation period.

[0223] • A function f representing the temperature change curve as the temperature decreases from the critical temperature Tc, or a table representing the temperature change curve.

[0224] Figure 11 This is a graph showing an example of the temperature change curve when cooling from the critical temperature Tc, such as... Figure 11 As shown in (B), the temperature change curve is represented by the function f(time) which represents the temperature (temp) with time as a parameter.

[0225] The function f can be obtained in the following way: (e.g.) Figure 11 As shown in (A), the coil cooling device was set to off during the design process. After the temperature of the magnet 104 rose to the critical temperature Tc, the coil cooling device was set to on again, and the temperature change of the magnet 104 was measured.

[0226] Figure 12 It is a graph representing the function Δf(temp0, Δtime) that gives the temperature change after time Δtime from the initial temperature temp0.

[0227] The definition of Δf(temp0, Δtime) can be expressed by the following formula.

[0228] [Formula 9]

[0229] Δf(temp0,Δtime)=f(time0+Δtime)-temp0

[0230] Here, time0 is the value that satisfies temp0=f(time0).

[0231] like Figure 11 As shown, the function f is monotonically decreasing, therefore uniquely determined, and can be expressed as time0 = f. -1 (temp0).

[0232] Based on the above, we can determine the demagnetization, excitation, and temperature changes caused by the cooling of the coil cooling device.

[0233] (Temperature immediately after excitation is completed)

[0234] For example, the temperature immediately after excitation is completed can be calculated as follows.

[0235] [Formula 10]

[0236] Temperature immediately after excitation = Temperature before demagnetization + Temperature rise caused by demagnetization + Δf(Temperature before demagnetization + Temperature rise caused by demagnetization, (Excitation start time - Demagnetization completion time)) + Temperature rise caused by excitation

[0237] (Temperature change when re-energized without sufficient cooling after demagnetization)

[0238] like Figure 7 As shown in (C), the temperature of the superconducting coil changes when it is re-energized without sufficient cooling after demagnetization.

[0239] Furthermore, the cooling time after excitation can be calculated using the following formula.

[0240] [Formula 11]

[0241] Cooling time after excitation = f -1 (Typical temperature) -f -1 (Temperature immediately after excitation is completed)

[0242] (Reasons for needing the temperatures at excitation and cooling completion)

[0243] like Figure 8 As shown, the excitation completion time and the predicted temperature at the excitation completion time are displayed in display bar 252 of operation screen 250-2, and the cooling completion time and the predicted temperature at the cooling completion time are displayed in display bar 253.

[0244] The reason for requiring the temperatures at which excitation and cooling are complete is that hospital staff want to confirm whether the patient's examination (imaging) can begin without any problems several hours later, and to alleviate any anxiety. Confirmation of magnetic field recovery (excitation complete or cooled to normal temperature) can be determined by whether the temperature of magnet 104 is low, and is therefore displayed on operation screen 250-2.

[0245] <Third Implementation Method>

[0246] Figure 13 This is a timing diagram showing the state of each part of the MRI apparatus in the third embodiment of the magnetic resonance imaging system according to the present invention.

[0247] in addition, Figure 13 (A) to (D) are respectively with Figure 9 The timing diagrams shown in (A) to (D) correspond to those of the second embodiment, so their detailed descriptions are omitted.

[0248] The third embodiment is an embodiment in which demagnetization and excitation are controlled when an inspection interval (e.g., an idle time of more than 2.5 hours) is generated.

[0249] According to the hospital, there are sometimes several hours of free time during a day of examinations.

[0250] In the examination room (shielded room) where the MRI device 100 is installed, it is safer to be without a magnetic field, so hospital staff have a request to reduce the magnetic field.

[0251] Therefore, after demagnetization begins, the time until recovery is displayed, allowing it to be determined whether the inspection schedule will be affected even if demagnetization is performed.

[0252] exist Figure 13 In the example shown in (A), the period from 11:00 to 14:00 is the idle time for inspection.

[0253] Figure 14 This is a diagram illustrating a third embodiment of the magnetic resonance imaging system according to the present invention, and in particular, a diagram illustrating the operation screen of the display.

[0254] Operator 220 Figure 14 In the operation screen 250-3 shown, enter the demagnetization start time (moment) in input field 258 and the excitation start time (moment) in input field 259.

[0255] Here, the degaussing start time entered in input field 258 is the start time of the idle time for inspection. As shown in [Formula 1], processor 202 calculates the degaussing completion time based on the degaussing start time and the degaussing time, and displays the degaussing completion time in display field 251. Thus, operator 220 can know the degaussing completion time. In addition, when the user operation start time for degaussing is indicated by a degaussing start button or other input, processor 202 can calculate the degaussing completion time using [Formula 1].

[0256] Furthermore, the excitation completion time and cooling completion time, calculated based on the excitation start time entered in input field 259, are displayed in display fields 252 and 253, respectively. Thus, the operator 220 can determine the end time of the inspection idle time (the time when the inspection can resume).

[0257] According to the third embodiment, the operator 220 can control the power supply of the magnet 104 (superconducting coil) by considering the recovery time on the operation screen 250-3, so that the magnetic field can be controlled by hospital staff even within a few hours.

[0258] <Fourth Implementation>

[0259] Figure 15 This is a timing diagram showing the state of each part of the MRI apparatus in the fourth embodiment of the magnetic resonance imaging system according to the present invention.

[0260] in addition, Figure 15 (A) to (D) are respectively with Figure 9 The timing diagrams shown in (A) to (D) correspond to those of the second embodiment, so their detailed descriptions are omitted.

[0261] The fourth implementation method is the implementation method for controlling demagnetization and excitation on the hospital's rest days.

[0262] Depending on the hospital, the use of all MRI machines 100 may be suspended on rest days and public holidays. Furthermore, the absence of magnetic fields in the shielded room where the MRI machines 100 are located is considered safer, therefore hospital staff may request that the magnetic field be reduced.

[0263] exist Figure 15 In the example shown in (A), the schedule is to stop examinations based on MRI device 100 between 11:00 a.m. on Saturday and 2:00 p.m. three days later (after public holidays).

[0264] That is, operator 220 will Figure 14The radio button 254 on the operation screen 250-3 is set to "On," enabling the setting of the excitation start date and time, as well as the demagnetization start date and time. The demagnetization start date and excitation start date can be set in list boxes 256 and 257. Furthermore, as mentioned above, the demagnetization start time and excitation start time can also be input through input fields 258 and 259.

[0265] Here, the degaussing start date and time are set according to the degaussing start date set in list box 256 and the degaussing start time entered in input field 258. The degaussing completion time calculated based on the degaussing start time is displayed in display field 251. Thus, the operator 220 can know the degaussing start date and degaussing completion time.

[0266] Furthermore, the excitation start date and time are set according to the excitation start date set in list box 257 and the excitation start time entered in input field 259. The excitation completion time and cooling completion time calculated based on the excitation start time are displayed in display fields 252 and 253. Thus, the operator 220 can keep track of the excitation start date, excitation completion time, and cooling completion time.

[0267] According to the fourth embodiment, excitation is completed even during holidays when the operator 220 is not present, thereby enabling the MRI device 100 to be used immediately on weekdays.

[0268] <Time control and calculation-based inspection functions>

[0269] The processor 202 has the function of checking whether the timing control of demagnetization / excitation is inconsistent with the calculation.

[0270] The time involved in demagnetization and excitation of the MRI device 100 equipped with a helium-saving coil cooling device ( Figure 10 The times shown are as follows.

[0271] (1) Demagnetization standby time: 30 minutes

[0272] (2) Demagnetization time: 60 minutes

[0273] (3) Excitation time: 60 minutes

[0274] (4) Time to return to normal temperature: 120 minutes

[0275] These times are stored in memory as design values ​​for each type of MRI device (e.g., E.Smart, E.Synergy).

[0276] Magnet 104 (superconducting coil 230) is always in a cooled state (only the compressor driven by the main power supply switches to the backup power). With demagnetization / excitation time controlled by a schedule, demagnetization takes more than one day; therefore, the time control for demagnetization / excitation will not fundamentally contradict the calculation. Furthermore, the start time for excitation is specified by the operator.

[0277] On the other hand, when the operator 220 wants to set the demagnetization / excitation within a time shorter than 2.5 hours, it will be intercepted in the calculation process because it is not within the time of (1) to (3) (or (1) to (4)) mentioned above.

[0278] Processor 202 checks whether there is a contradiction between the excitation start time and the demagnetization start time (i.e., the following is true).

[0279] A. Excitation completion time - User operation start time > Demagnetization standby time (1) + Demagnetization time (2) + Excitation time (3)

[0280] like Figure 10 As shown, the processor 202 determines whether the total time of (1) to (3) above is within the time from the start of the user operation to the completion of the excitation.

[0281] Although the time (4) for the MRI device 100 to return to normal temperature after excitation is not necessary for the contradiction determination, the time (4) can be further added in order to notify the MRI device 100 that it is in a stable state, and the contradiction determination is made by taking into account the total time of (1) to (4) above.

[0282] Furthermore, in the case of an MRI device that does not require a demagnetization standby time from the start of magnet demagnetization to the start of magnet demagnetization, the demagnetization standby time (1) is of course zero.

[0283] If the processor 202 receives a demagnetization start command, it obtains the operable time from the start of demagnetization of the magnet 104 to the next time the MRI device 100 can start operating, based on the received demagnetization start time and the design values ​​of the MRI device 100. It can calculate the demagnetization completion time according to [Equation 1]. If the demagnetization completion time is calculated, it can calculate the excitation completion time from the demagnetization completion time according to [Equation 2] or [Equation 2']. If the excitation completion time is further calculated, it can calculate the post-excitation cooling completion time according to [Equation 3].

[0284] Therefore, the processor 202 can calculate the operable time (excitation completion time or excitation cooling completion time) when the MRI device 100 can be restarted based on the demagnetization start time and the design values ​​of the MRI device 100 (standby time, demagnetization time, excitation time, pre-excitation waiting time, post-excitation cooling time, etc.).

[0285] Furthermore, the aforementioned calculation formulas can be stored in memory 204, and the design values ​​of the MRI device 100 can be stored along with the calculation formulas as constants. Alternatively, a table corresponding to each calculation formula can be stored in memory 204 instead of the individual calculation formulas. The processor 202 can read the required calculation formulas or tables from memory 204 and use the calculation formulas or tables to obtain the runtime, etc.

[0286] Furthermore, if the processor 202 determines that the user-set start time of the MRI device 100 is earlier than the time when it can be run, it is a contradiction with the user-set start time.

[0287] When the processor 202 determines that there is a conflict between the user-set start time and the scheduled operation, it may notify the user of the conflicting content through the operation screen of the display 208, or instruct the user to correct the schedule such as the user-set start time through the operation screen of the display 208.

[0288] B. Processor 202 checks whether the predicted temperature immediately after excitation is below the critical temperature Tc.

[0289] The temperature immediately after excitation is completed can be calculated using the above [Equation 10].

[0290] If the temperature immediately after excitation, as calculated by [Equation 10], exceeds the critical temperature Tc, it is not suitable to restart the MRI device 100. The operator 220 can access the operation via the display screen 208. Figure 8 The temperature immediately after excitation is completed is confirmed by displaying bar 252 on the operation screen 250-2. Preferably, if the temperature immediately after excitation exceeds the critical temperature Tc, the processor 202 will, for example, change the temperature displayed on display bar 252 of the operation screen 250-2 to red text and issue a warning to the operator 220.

[0291] <Fifth Implementation>

[0292] Figure 16 This is a schematic diagram illustrating a fifth embodiment of the magnetic resonance imaging system according to the present invention, particularly showing a system for communication and information sharing between the hospital side and the supplier side.

[0293] exist Figure 16 Even if the power supply to the main body of the MRI device 100 is cut off for several days due to reasons such as a planned power outage at Hospital A, as long as the demagnetization / excitation time control, the state of the magnetic field, and the temperature of the magnet 104 are visualized, the professional technicians 310 on the supplier side of the MRI device 100 can remotely access Hospital A to easily confirm the recovery status of the MRI device 100.

[0294] like Figure 14 As shown, if the user sets the demagnetization start time and excitation start time using the input fields 258 and 259 of the operation screen 250-3 on the display 208, the demagnetization completion time, excitation completion time, and cooling completion time are calculated and displayed in the display fields 251, 252, and 253 of the operation screen 250-3, respectively. However, in the fifth embodiment, in Figure 16 In the operation screen 250-5 of the display 208 shown, and Figure 14 Similarly, in the operation screen 250-3 shown, the demagnetization completion time, excitation completion time, and cooling completion time are displayed in the display bars 251, 252, and 253 of the operation screen 250-5, respectively.

[0295] and, Figure 16 The operation screen 250-5 shown has a coil temperature display unit 270, and the processor 202 displays the temperature of the superconducting coil (magnet 104) at all times on the coil temperature display unit 270.

[0296] That is, the MRI device 100 includes a temperature sensor 238 (reference) for detecting the temperature of the magnet 104 or the superconducting coil 230. Figure 3 The processor 202 displays the temperature detected by the temperature sensor 238 at each moment on the coil temperature display unit 270 of the operation screen 250-5. This coil temperature display unit 270 displays a graph representing the coil temperature with the horizontal axis set to the time axis. Furthermore, it is preferable to also display the critical temperature Tc on the graph. Moreover, since the coil temperature can be predicted, the coil temperature display unit 270 can display not only the monitored coil temperature but also the predicted coil temperature.

[0297] In the fifth embodiment, such as Figure 16 As shown, the demagnetization completion time, excitation completion time, cooling completion time, and coil temperature information displayed on the hospital-side operation screen 250-5 are notified to the supplier-side via the network. Information indicating the status of the MRI device 100 in hospital A is displayed on the supplier-side display screen 300, thereby enabling the hospital-side and supplier-side to share information.

[0298] According to the fifth embodiment, for example, even if the MRI device 100 stops operating for several days, the supplier does not need to send a professional technician 310, thus reducing trouble and time.

[0299] [Methods for notifying suppliers]

[0300] <Consultation>

[0301] Figure 16The operation screen 250-5 shown has a consultation button 271 for contacting the supplier's professional technicians 310. If the operator 220 operates (clicks) the consultation button 271, the processor 202 can consult with the professional technicians 310 (by phone and / or by sending emails automatically, etc.) and notify the supplier of the information displayed on the operation screen 250-5 (the information notified to the operator 220) and display it on the supplier's side display screen 300.

[0302] <Automatic Notification>

[0303] Figure 16 The operation screen 250-5 shown has an automatic notification enable button 272. If the operator 220 sets the automatic notification enable button 272 to be enabled, the processor 202 will notify the supplier of the information displayed on the operation screen 250-5 and display it on the supplier's display 300 when the specified conditions are met.

[0304] The conditions for meeting the specified conditions can be defined as the case where the temperature of the superconducting coil 230 exceeds the temperature threshold Th and / or is below the temperature threshold Th.

[0305] Figure 17 This is a graph illustrating an example of how coil temperature changes with time-controlled demagnetization / excitation.

[0306] like Figure 17 As shown, the temperature of the superconducting coil 230, which has been cooled to its normal temperature, rises due to demagnetization. This temperature rise is defined as the first temperature rise.

[0307] Next, after the temperature rises due to demagnetization, the temperature of the superconducting coil 230 decreases through cooling based on the coil cooling device. This temperature decrease is designated as the first temperature decrease.

[0308] After the first temperature drop, the temperature of the superconducting coil 230 rises due to excitation. This temperature rise is designated as the second temperature rise.

[0309] Next, after the temperature rises due to excitation, the temperature of the superconducting coil 230 decreases due to cooling by a coil cooling device. This temperature decrease is designated as the second temperature decrease.

[0310] If automatic notification is enabled via the automatic notification enable button 272, such as Figure 17 As shown, if the temperature exceeds the temperature threshold Th due to the second temperature rise, the processor 202 will notify the supplier of the information displayed on the operation screen 250-5 at the moment the temperature threshold Th is exceeded, and display it on the supplier's side display 300.

[0311] If the temperature exceeds the temperature threshold Th due to a second temperature rise, the MRI device 100 normally begins to resume operation, preferably notifying the supplier at that moment.

[0312] Furthermore, if automatic notifications are enabled, such as Figure 17 As shown, if the temperature drops below the temperature threshold Th due to the second temperature drop, the processor 202 can notify the supplier of the information displayed on the operation screen 250-5 at the moment when the temperature drops below the temperature threshold Th, and display it on the supplier's side display 300.

[0313] If the temperature drops below the temperature threshold Th due to a second temperature drop, the MRI device 100 is fully recovering, and the supplier should preferably be notified at this time.

[0314] In addition, as a specified condition, setting automatic notification activation via the automatic notification activation button 272 is also one of the conditions, but it is also possible to only consider the case where the temperature exceeds the temperature threshold Th due to the second temperature rise or falls below the temperature threshold Th due to the second temperature drop without setting the automatic notification activation button 272.

[0315] <Saving Schedule>

[0316] like Figure 14 As shown, the operation screen 250-3 of the display 208 has a save button 260 for saving a schedule that includes the user-set demagnetization start time and excitation start time of the magnet 104. When the operator 220 sets the schedule and operates (clicks) the save button 260, the processor 202 saves the user-set schedule in the memory 204 and displays it on the screen. Figure 16 The information shown on the operation screen 250-5 (the information notified to the operator 220) is communicated to the supplier and displayed on the supplier's side display 300.

[0317] Therefore, the operator 220 does not need to consider notifying the supplier, but can automatically notify the supplier of the information displayed on the operation screen 250-3 in conjunction with the operation of the save button 260.

[0318] In addition, the operation button for automatically notifying the supplier of the information displayed on the operation screen 250-3 is not limited to the automatic notification start button 272 or the save button 260.

[0319] How Magnetic Resonance Imaging Systems Work

[0320] Figure 18 This is a flowchart illustrating an embodiment of the working method of the magnetic resonance imaging system involved in this invention.

[0321] Figure 2The processor 202 of the magnetic resonance imaging system 10 shown is in accordance with Figure 18 The flowchart shown receives various instruction inputs from the operation unit 210 and performs processing corresponding to the received instruction inputs.

[0322] exist Figure 18 In step S100, the processor 202 determines whether it has received a confirmation command to start demagnetizing the magnet 104 via a user interface including the display 208 and the operation unit 210. For example, the processor 202 in... Figure 4 On the operation screen of the display 208 shown, when the "off" button for demagnetizing the magnet 104 is pressed, a confirmation command to start demagnetizing is received.

[0323] Upon receiving a confirmation command to begin demagnetization (in the case of "Yes"), the processor 202 calculates the demagnetization completion time when the demagnetization of the magnet 104 begins, the excitation completion time when the next excitation of the magnet 104 is completed after demagnetization, the time when the MRI device 100 can be restarted after demagnetization, and the cooling completion time after excitation (steps S102 to S108).

[0324] These times can be calculated based on the current time and the design values ​​of the MRI device 100 stored in the memory 204. Furthermore, if the operable time is the excitation completion time or the cooling completion time after excitation, it is not necessary to calculate the operable time. If the time between the excitation completion time and the cooling completion time after excitation (for example, an intermediate time) is used, that time can be set as the operable time.

[0325] Next, the processor 202 displays the four time points calculated in steps S102 to S108 on the operation screen (step S110). Additionally, in Figure 5 The excitation completion time is displayed in the display bar 246 of the operation screen 250-1 shown, but as mentioned above, it can display 4 times.

[0326] Next, the processor 202 determines whether to turn on the "Start" button 244 to begin demagnetization (step S111). If the "Start" button 244 is not turned on ("No"), the process returns to step S102 and repeats steps S102 to S110.

[0327] With the "Start" button 244 turned on ("Yes"), the process transitions to step S112, where the processor 202 determines whether a degaussing date and time have been specified. The degaussing date and time can be... Figure 14 The operation screen shown in 250-3 is specified.

[0328] If the processor 202 determines in step S112 that a degaussing date and time have been specified (if "Yes"), it then determines whether the degaussing start date and time have been saved (step S114). Whether the degaussing start date and time have been saved can be determined by pressing the save button 260 (see reference). Figure 14 Whether it is turned on is used to determine this.

[0329] In step S114, if it is determined that the demagnetization start date and time are not saved ("No"), return to step S112; if it is determined that the demagnetization start date and time are saved ("Yes"), proceed to step S116.

[0330] In step S116, the processor 202 puts the system into standby mode while the magnet 104 is energized until the demagnetization start date and time. If the demagnetization start date and time are reached, the process transitions to step S118, where the demagnetization of the magnet 104 begins.

[0331] On the other hand, in step S112, if it is determined that no demagnetization date and time are specified ("No"), the processor 202 transitions the process to step S118, where the demagnetization of the magnet 104 begins.

[0332] If demagnetization of magnet 104 begins, processor 202 transitions the process to step S120, where it is determined whether an excitation date and time have been specified. The excitation date and time can be determined by... Figure 14 The operation screen shown in 250-3 is specified.

[0333] In step S120, if it is determined that an excitation date and time have been specified ("yes"), processor 202 then determines whether the excitation start date and time have been saved (step S122). Whether the excitation start date and time have been saved can be determined by using the save button 260 (see reference). Figure 14 Whether it is turned on is used to determine this.

[0334] In step S122, if it is determined that the excitation start date and time have not been saved ("No"), then return to step S120; if it is determined that the excitation start date and time have been saved ("Yes"), then proceed to step S124.

[0335] In step S124, the processor 202 puts the system into standby mode while the magnet 104 is demagnetized until the excitation start date and time. If the excitation start date and time are reached, the process transitions to step S126, where the magnet 104 is excited.

[0336] On the other hand, in step S120, if it is determined that the excitation date and time are not specified (in the case of "No"), the processor 202 transitions the process to step S126, where the excitation process of the magnet 104 is performed.

[0337] In addition, during the excitation process, excitation begins after confirming that demagnetization has been completed and that the actual temperature has dropped to a temperature suitable for excitation. In the absence of a specified excitation date and time, in this example, in the MRI device corresponding to Mode 1, excitation begins immediately after demagnetization is completed. In the MRI device corresponding to Mode 2, excitation begins after a waiting period before standby excitation following demagnetization.

[0338] [other]

[0339] In this embodiment, each process of the processor is executed by any computer. Furthermore, any computer can execute these processes via a processor as hardware, a program as software, or a combination thereof. In this case, the processor is configured to cooperate with the program to execute the various processes in this embodiment, and can function as units or means in this embodiment. Moreover, the execution order of the processor-based processes is not limited to the order described and can be appropriately varied. Any computer can be a general-purpose computer, a special-purpose computer, a workstation, or other system capable of executing the processes.

[0340] A processor can be composed of one or more hardware components, and the type of hardware is not limited. For example, a processor can be composed of programmable logic devices such as CPUs (Central Processing Units), MPUs (Micro Processing Units), FPGAs (Field Programmable Gate Arrays), dedicated circuits for performing specific processes such as ASICs (Application Specific Integrated Circuits), GPUs (Graphics Processing Units), or NPUs (Neural Processing Units). Furthermore, the type of hardware can be a combination of different types of hardware. When multiple hardware components are configured to execute one or more processes of a certain processor, these multiple hardware components can exist in physically separate devices or in the same device. Moreover, in any embodiment, the steps of each processor-based process are not limited to the steps described above and can be appropriately modified. Additionally, the hardware can be composed of circuits, such as those combining semiconductor elements.

[0341] Furthermore, the program can be software such as firmware or microcode. It can also be, for example, a group of program modules, each of which can be implemented by a processor configured to execute that function. The program can also be program code or multiple code segments stored on one or more non-transitory computer-readable media (e.g., storage media or other memory). The program can be divided and stored on multiple non-transitory computer-readable media existing in physically separate devices. Program code or code segments can represent any combination of procedures, functions, subroutines, routines, subroutines, modules, software packages, classes, commands, data structures, or program statements. Program code or code segments can be connected to other code segments or hardware circuitry by sending and receiving information, data, arguments, parameters, or memory contents.

[0342] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

Claims

1. A magnetic resonance imaging system, comprising a magnetic resonance imaging device, a processor, and a user interface, wherein, The magnetic resonance imaging apparatus includes: a superconducting magnet comprising a superconducting coil cooled to a first temperature to become superconducting; and a coil cooling device that cools the superconducting coil by heat conduction caused by contact between a heat-conducting component cooled via a cold head and the superconducting coil, thereby bringing it to the first temperature. The processor performs the following processing: Based on the demagnetization start time of the superconducting magnet and the design value of the magnetic resonance imaging device, obtain the time from the start of the demagnetization of the superconducting magnet to the next time the magnetic resonance imaging device can start operating. and The operator is notified of the operational availability via the user interface.

2. The magnetic resonance imaging system according to claim 1, wherein, The design values ​​for the magnetic resonance imaging device include the demagnetization time from the start to the completion of demagnetization of the superconducting magnet and the excitation time from the start to the completion of excitation of the superconducting magnet. The processor obtains the operable time by adding the demagnetization time and the excitation time to the demagnetization start time.

3. The magnetic resonance imaging system according to claim 2, wherein, If the demagnetization control corresponding to the demagnetization time and the excitation control corresponding to the excitation time are made continuous, then when the temperature of the superconducting coil exceeds a second temperature that is higher than the first temperature, The design parameters of the magnetic resonance imaging device also include the waiting time from the completion of demagnetization of the superconducting magnet to the start of excitation of the superconducting magnet. The processor obtains the runnable time by adding the demagnetization time, the waiting time, and the excitation time to the demagnetization start time.

4. The magnetic resonance imaging system according to claim 1, wherein, The design values ​​of the magnetic resonance imaging device include the demagnetization time from the start to the completion of demagnetization of the superconducting magnet, the excitation time from the start to the completion of excitation of the superconducting magnet, and the post-excitation cooling time from the completion of excitation of the superconducting magnet until the temperature of the superconducting coil returns to the first temperature. The processor obtains the runnable time by adding the demagnetization time, the excitation time, and the post-excitation cooling time to the demagnetization start time.

5. The magnetic resonance imaging system according to claim 1, wherein, The design values ​​of the magnetic resonance imaging device include the demagnetization standby time from the start of demagnetization of the superconducting magnet as instructed by the operator to the start of demagnetization of the superconducting magnet, the demagnetization time from the start to the completion of demagnetization of the superconducting magnet, the excitation time from the start to the completion of excitation of the superconducting magnet, and the post-excitation cooling time from the completion of excitation of the superconducting magnet to the temperature of the superconducting coil returning to the first temperature. The processor obtains the operable time by adding the demagnetization standby time, the demagnetization time, the excitation time, and the post-excitation cooling time to the demagnetization start time.

6. The magnetic resonance imaging system according to claim 1, wherein, The processor performs the following processing: Obtain the demagnetization start time and the demagnetization time of the superconducting magnet from start to completion; Obtain the demagnetization completion time by adding the demagnetization time to the demagnetization start time; and The operator is notified of the demagnetization completion time via the user interface.

7. The magnetic resonance imaging system according to claim 1, further comprising a memory storing calculation formulas or tables containing design values ​​for the magnetic resonance imaging device. The processor performs the following processing: Using the demagnetization start time and the calculation formula or table, at least the operable time can be obtained.

8. The magnetic resonance imaging system according to claim 7, wherein, The processor performs the following processing: The temperature of the superconducting coil is predicted under at least one of the following conditions: excitation of the superconducting magnet is complete, or cooling of the superconducting magnet after excitation is complete. The predicted temperature is then communicated to the operator via the user interface.

9. The magnetic resonance imaging system according to claim 1, wherein, The processor performs the following processing: Receive a schedule containing the user-defined demagnetization start time and excitation start time of the superconducting magnet; and The schedule is notified to the operator via the user interface.

10. The magnetic resonance imaging system according to claim 9, wherein, The schedule includes the start time of operation of the magnetic resonance imaging device. The processor performs the following processing: Check whether the start time of the operation is earlier than the runnable time; and If the start time of the run is earlier than the runnable time, the operator is notified of the contradiction between the start time and the start time via the user interface, or the schedule is instructed to be corrected.

11. The magnetic resonance imaging system according to claim 1, further comprising a temperature sensor for detecting the temperature of the superconducting magnet or the superconducting coil. The processor notifies the operator of the temperature detected by the temperature sensor at each moment via the user interface.

12. The magnetic resonance imaging system according to claim 1, 9, or 11, wherein, The user interface includes a consultation button for consulting with technical personnel from the supplier of the magnetic resonance imaging device. The processor performs the following processing: When the consultation button is activated, the user can consult with the technical expert and the information communicated to the user via the user interface will be sent to the supplier.

13. The magnetic resonance imaging system according to claim 1, 9, or 11, wherein, The user interface has operation buttons that can automatically notify the supplier of the magnetic resonance imaging device. The processor performs the following processing: Based on the operation of the operation button, the information that was notified to the operator via the user interface is then notified to the supplier.

14. The magnetic resonance imaging system according to claim 1, 9, or 11, wherein, The processor performs the following processing: In the event of at least one of the following: after the superconducting magnet is demagnetized, its temperature is lowered by the coil cooling device and then rises to exceed a temperature threshold due to excitation; or after the excitation of the superconducting magnet is completed, its temperature is lowered by the coil cooling device and falls below the temperature threshold, the information that was previously communicated to the operator via the user interface will be communicated to the supplier of the magnetic resonance imaging device.

15. The magnetic resonance imaging system according to claim 13, wherein, The operation button is the automatic notification activation button. The processor performs the following processing: In the event that at least one of the following occurs: the automatic notification activation button is set to on, the superconducting magnet is demagnetized, and the temperature of the superconducting magnet decreases through the coil cooling device and then rises to exceed a temperature threshold due to excitation; or the superconducting magnet is excited and the temperature of the superconducting magnet decreases to below the temperature threshold through the coil cooling device, the information that was previously communicated to the operator via the user interface will be communicated to the supplier of the magnetic resonance imaging device.

16. The magnetic resonance imaging system according to claim 13, wherein, The operation button is a save button for saving a schedule that includes the user-defined demagnetization start time and excitation start time of the superconducting magnet. When the save button is pressed, the user interface saves the schedule in memory and notifies the supplier of the magnetic resonance imaging device of the information that was communicated to the operator via the user interface.

17. A method for operating a magnetic resonance imaging system, wherein, The magnetic resonance imaging system includes a magnetic resonance imaging device, a processor, and a user interface. The magnetic resonance imaging apparatus includes: a superconducting magnet comprising a superconducting coil cooled to a first temperature to become superconducting; and a coil cooling device that cools the superconducting coil by heat conduction caused by contact between a heat-conducting component cooled via a cold head and the superconducting coil, thereby bringing it to the first temperature. The operation method of the magnetic resonance imaging system includes the following steps: The processor obtains the operable time from the start of the demagnetization of the superconducting magnet to the next time the magnetic resonance imaging device can start operating, based on the demagnetization start time of the superconducting magnet and the design value of the magnetic resonance imaging device. and The processor notifies the operator of the runnable time via the user interface.

18. The method of operating the magnetic resonance imaging system according to claim 17, further comprising the following steps: The processor acquires the demagnetization start time and the demagnetization time of the superconducting magnet from start to completion; The processor obtains the demagnetization completion time by adding the demagnetization time to the demagnetization start time; and The processor notifies the operator of the demagnetization completion time via the user interface.

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