METHOD FOR ADJUSTING STATIC MAGNETIC FIELD HOMOGENEITY, STATIC MAGNETIC FIELD GENERATION DEVICE FOR MAGNETIC RESONANCE IMAGING, MAGNETIC FIELD ADJUSTMENT SYSTEM, AND PROGRAM
First Claim
1. A method for adjusting the homogeneity of a static magnetic field generated by static magnetic field generation unit in a measurement space by placing magnetic field correction unit that generates a corrected magnetic field, including:
- measuring a static magnetic field generated by the static magnetic field generation unit;
expanding the spatial distribution of the measured static magnetic field in a series;
first magnetic field adjustment for correcting the irregular magnetic field components of high-order terms from among the irregular magnetic field components that are expended in a series; and
second magnetic field adjustment for adjusting the irregular magnetic field components of low orders, to be executed after the first magnetic field adjustment.
4 Assignments
0 Petitions
Accused Products
Abstract
In order to avoid the duplication of the period and cost required for magnetic field adjustment, minimize the magnetic field adjustment period in a final installation site, and achieve highly efficient magnetic field adjustment of a magnet, a method for adjusting the homogeneity of a static magnetic field generated in a measurement space by a static magnetic field generation means by disposing magnetic field correction means for generating a corrected magnetic field with respect to the static magnetic field comprises: a step for measuring the static magnetic field generated by the static magnetic field generation means; a step for expanding the spatial distribution of the measured static magnetic field in a series; a first magnetic field adjustment step for correcting a high-order term irregular magnetic field components expanded in a series; and a second step for adjusting a low-order irregular magnetic field component, the second step being performed after the first adjustment step.
22 Citations
18 Claims
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1. A method for adjusting the homogeneity of a static magnetic field generated by static magnetic field generation unit in a measurement space by placing magnetic field correction unit that generates a corrected magnetic field, including:
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measuring a static magnetic field generated by the static magnetic field generation unit; expanding the spatial distribution of the measured static magnetic field in a series; first magnetic field adjustment for correcting the irregular magnetic field components of high-order terms from among the irregular magnetic field components that are expended in a series; and second magnetic field adjustment for adjusting the irregular magnetic field components of low orders, to be executed after the first magnetic field adjustment. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9)
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2. A method for adjusting the homogeneity of the static magnetic field generated by static magnetic field generation unit in a measurement space by placing magnetic field correction unit which generates a corrected magnetic field, including:
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measuring a static magnetic field generated by the static magnetic field generation unit; expanding the spatial distribution of the measured static magnetic field in a series; first magnetic field adjustment for adjusting the irregular magnetic field components of high-order terms from among the irregular magnetic field components that are expanded in a series, in a first installation site at which the static magnetic field generation unit is placed; and second magnetic field adjustment for adjusting the irregular magnetic field components of low orders from among the irregular magnetic fields that are expanded in a series, after the static magnetic field generation unit is transferred to a second installation site which is different from the first site.
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10. A static magnetic field generation device for magnetic resonance imaging which generates a static magnetic field in an imaging space in which an examination target is placed, comprising:
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a static magnetic field generation unit; and a magnetic field correction unit configured to adjust the static magnetic field, wherein the magnetic field correction unit comprises shim trays having plural storage portions for storing magnetic body pieces, that are first shim trays for adjusting at least the irregular magnetic field of high-order terms and second shim trays for adjusting at least the irregular magnetic field of low orders. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A magnetic field adjustment system for adjusting the homogeneity of a static magnetic field generated by a static magnetic field generation device, comprising:
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magnetic field measurement unit configured to measure the magnetic field distribution of the static magnetic field; a storage unit configured to store a magnetic field correction unit to be used for adjusting the homogeneity of the static magnetic field; and a calculation unit configured to calculate the shim quantity using the magnetic field distribution measured by the magnetic field measurement unit and the information of the magnetic field correction unit stored in the storage unit, wherein the calculation unit performs, from the measured magnetic field distribution, a first calculation for calculating the shim quantity for correcting the irregular magnetic field of high-order terms and a second calculation for calculating the shim quantity for correcting the irregular magnetic field of low-order terms. - View Dependent Claims (17, 18)
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Specification