JP2002336216A5 - - Google Patents

Claims (10)

A magnetic resonance imaging apparatus comprising a static magnetic field generation device having a pair of upper and lower static magnetic field generation sources arranged across a space in which a subject is placed, and a container storing each static magnetic field generation source, The static magnetic field source comprises one or more superconducting coils, and the container contains a cryogen that maintains the superconducting coils at a constant temperature,
Measuring means installed in at least one of the containers for transmitting an electrical signal corresponding to the amount of cryogen, a calculation means for inputting a signal from the measuring means and calculating a cryogen amount and / or a change in the amount of the cryogen, and at least A magnetic resonance imaging apparatus, comprising: a cryogen amount in one container and / or a display unit that displays a change in the cryogen amount.   The magnetic resonance imaging apparatus according to claim 1, wherein the measurement unit is provided for each container, and the display unit displays a cryogen amount and / or a change in the cryogen amount in each container. Imaging device.   3. The magnetic resonance imaging apparatus according to claim 1, further comprising means for issuing a warning when the amount of the cryogen reaches a predetermined lower limit value or when the change in the amount of the cryogen exceeds a predetermined value. A magnetic resonance imaging apparatus.   4. The magnetic resonance imaging apparatus according to claim 1, wherein the measurement unit and the calculation unit are controlled so that measurement by the measurement unit and calculation by the calculation unit are performed at desired time intervals. A magnetic resonance imaging apparatus comprising control means for performing   A pair of cryostuds for storing superconducting coils disposed opposite to each other to provide a space for imaging a subject based on a magnetic resonance phenomenon, and upper superconductivity disposed near the bottom of the upper cryostud A coil, a cryogen filled in the upper cryostud for cooling the upper superconducting coil, a lower superconducting coil disposed near the top of the lower cryostud, and a cooling for the lower superconducting coil A cryogen filled in the lower cryostud, an upper liquid level sensor provided on the upper cryostat and detecting the liquid level of the cryogen filled therein, and a lower cryostud The lower liquid level sensor that detects the level of the cryogen filled in and the detection signals from the upper and lower liquid level sensors are individually processed. A measurement circuit, an arithmetic circuit for calculating the amount of residual cryogen in the upper and lower cryostats based on individual measurement signals from the measurement circuit, and an upper and lower cryostud based on the calculation results of the arithmetic circuit An open type magnetic resonance imaging apparatus having a display device for individually displaying the amount of residual cryogen in the medium. A storage device for storing the calculation result of the calculation circuit and the allowable lower limit residual cryogen amount of the cryogen in the upper and lower cryostats, the allowable decrease amount per unit time or the allowable decrease rate;
The arithmetic circuit further calculates a residual cryogen amount, a reduction amount per unit time, or a reduction rate based on the current calculation result and the previous calculation result stored in the storage device, and the calculation result and the storage 6. The open type magnetic resonance imaging apparatus according to claim 5, wherein the permissible lower limit residual cryogen amount, the permissible decrease amount per unit time, or the permissible decrease rate of each cryogen stored in the apparatus is compared and calculated.   When the comparison result by the arithmetic circuit exceeds the allowable lower limit residual cryogen amount, the allowable decrease amount per unit time, or the allowable decrease rate of the cryogen in the upper and lower cryostats, the display device is 7. The open type magnetic resonance imaging apparatus according to claim 6, wherein an alarm is individually issued for the side cryostud.   8. The magnetism according to claim 7, wherein the amount of the cryogen in the upper and lower cryostats and the amount of the cryogen decreased per unit time are measured, and the date and time when the cryogen amount is replenished is predicted and displayed on the display device. Resonance imaging device.   In the magnetic resonance imaging apparatus provided with a static magnetic field generation apparatus having a pair of upper and lower static magnetic field generation sources arranged across a space in which a subject is placed, and a container storing each static magnetic field generation source, each static magnetic field The generation source includes one or more superconducting coils, and the container includes a cryogen that maintains the superconducting coil at a constant temperature, and a measuring unit that measures the amount of the cryogen, and the measuring unit is a portion of the portion immersed in the cryogen. A magnetic resonance imaging apparatus comprising a material having an internal resistance of zero.   The magnetic resonance imaging apparatus according to claim 9, wherein the measuring unit measures a voltage applied to the material and measures a length from one end of the material to a liquid surface of a cryogen.