JP2004261591A5 - - Google Patents
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- JP2004261591A5 JP2004261591A5 JP2004030577A JP2004030577A JP2004261591A5 JP 2004261591 A5 JP2004261591 A5 JP 2004261591A5 JP 2004030577 A JP2004030577 A JP 2004030577A JP 2004030577 A JP2004030577 A JP 2004030577A JP 2004261591 A5 JP2004261591 A5 JP 2004261591A5
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- magnetic field
- correction
- imaging apparatus
- resonance imaging
- irregular
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Claims (9)
前記補正磁場制御手段は、前記傾斜磁場に対して非線形に応答して発生する不整磁場を、前記傾斜磁場波形を規定する少なくとも一つのパラメータ毎に対応して補正することを特徴とする磁気共鳴イメージング装置。 A static magnetic field generating means for applying a static magnetic field to the measurement space, a gradient magnetic field generating means for applying a gradient magnetic field in each of the slice direction, the phase encoding direction, and the frequency encoding direction, and the irregular magnetic field induced by the application of the gradient magnetic field are corrected. A correction coil and calibration data are provided for each spatial component, and the current supplied to the correction coil is controlled based on the calibration data, thereby controlling the correction magnetic field corresponding to the temporal change of the irregular magnetic field for each spatial component. In a magnetic resonance imaging apparatus provided with a correction magnetic field control means for
The correction magnetic field control means corrects an irregular magnetic field generated in response to the gradient magnetic field in a nonlinear manner corresponding to at least one parameter that defines the gradient magnetic field waveform. apparatus.
前記パラメータの一つが前記傾斜磁場波形の振幅であり、
前記補正磁場制御手段は、前記振幅に対応して前記補正磁場を制御することを特徴とする磁気共鳴イメージング装置。 The magnetic resonance imaging apparatus according to claim 1.
One of the parameters is the amplitude of the gradient magnetic field waveform,
The magnetic resonance imaging apparatus characterized in that the correction magnetic field control means controls the correction magnetic field corresponding to the amplitude .
前記パラメータの一つが前記傾斜磁場波形の形状であり、
前記補正磁場制御手段は、前記形状に対応して前記補正磁場を制御することを特徴とする磁気共鳴イメージング装置。 The magnetic resonance imaging apparatus according to claim 1 or 2,
One of the parameters is the shape of the gradient magnetic field waveform,
The magnetic resonance imaging apparatus characterized in that the correction magnetic field control means controls the correction magnetic field corresponding to the shape .
前記補正磁場制御手段は、前記傾斜磁場の印加履歴に対応して前記補正磁場を制御することを特徴とする磁気共鳴イメージング装置。 The magnetic resonance imaging apparatus according to any one of claims 1 to 3 ,
The magnetic resonance imaging apparatus characterized in that the correction magnetic field control means controls the correction magnetic field corresponding to the application history of the gradient magnetic field .
前記較正データは前記空間成分毎のヒステリシス曲線を有し、
前記補正磁場制御手段は、前記ヒステリシス曲線にもとづいて前記補正磁場を制御することを特徴とする磁気共鳴イメージング装置。 The magnetic resonance imaging apparatus according to any one of claims 1 to 4 ,
The calibration data has a hysteresis curve for each spatial component;
The magnetic resonance imaging apparatus characterized in that the correction magnetic field control means controls the correction magnetic field based on the hysteresis curve .
前記空間成分は、更に局所空間成分を含み、
前記補正磁場制御手段は、更に前記局所空間成分に対応する補正コイルを備えたことを特徴とする磁気共鳴イメージング装置。 The magnetic resonance imaging apparatus according to any one of claims 1 to 5 ,
The spatial component further includes a local spatial component,
The magnetic resonance imaging apparatus, wherein the correction magnetic field control means further includes a correction coil corresponding to the local space component .
( a ) テスト傾斜磁場の印加によって誘起される前記不整磁場を空間成分毎に求めて、該不整磁場を補正する較正データを空間成分毎に得る工程と、 (a) obtaining the irregular magnetic field induced by applying the test gradient magnetic field for each spatial component, and obtaining calibration data for correcting the irregular magnetic field for each spatial component;
( b ) 前記( a )の工程を前記テスト傾斜磁場の振幅を変えて繰り返し、該振幅毎でかつ前記空間成分毎に前記較正データを得る工程と、 (b) repeating the step (a) while changing the amplitude of the test gradient magnetic field to obtain the calibration data for each amplitude and for each spatial component;
( c ) 前記較正データに基づいて、印加される傾斜磁場の振幅に対応して前記不整磁場を空間成分毎に打ち消すような補正電流を求める工程と、 (c) obtaining a correction current based on the calibration data so as to cancel the irregular magnetic field for each spatial component corresponding to the amplitude of the applied gradient magnetic field;
( d ) 前記( c )の工程で求めた空間成分毎の補正電流を、対応する空間成分の補正磁場を発生する補正コイルに、前記傾斜磁場の印加に同期して供給する工程と、 (d) supplying a correction current for each spatial component obtained in the step (c) to a correction coil that generates a correction magnetic field for the corresponding spatial component in synchronization with the application of the gradient magnetic field;
とを備えることを特徴とする不整磁場補正方法。An irregular magnetic field correction method comprising:
前記工程( b )と( c )の間に
( e ) 前記( b )の工程を前記テスト傾斜磁場の形状を変えて繰り返し、該形状毎に前記較正データを得る工程を有し、
前記( c )の工程において、印加される傾斜磁場の形状にも対応して前記不整磁場を打ち消すよう補正電流を求めることを特徴とする不整磁場補正方法。 The irregular magnetic field correction method according to claim 7,
Between the steps (b) and (c)
(e) repeating the step (b) while changing the shape of the test gradient magnetic field, and obtaining the calibration data for each shape,
In the step (c), the irregular magnetic field correction method is characterized in that a correction current is obtained so as to cancel the irregular magnetic field corresponding to the shape of the applied gradient magnetic field.
前記較正データが前記空間成分毎のヒステリシス曲線であり、前記( c )の工程において、該ヒステリシス曲線に基づいて前記補正電流を求めることを特徴とする不整磁場補正方法。
The irregular magnetic field correction method according to claim 7 or 8,
The method for correcting an irregular magnetic field, wherein the calibration data is a hysteresis curve for each spatial component, and the correction current is obtained based on the hysteresis curve in the step (c).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004030577A JP4343726B2 (en) | 2003-02-12 | 2004-02-06 | Magnetic resonance imaging apparatus and irregular magnetic field correction method |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003033333 | 2003-02-12 | ||
| JP2004030577A JP4343726B2 (en) | 2003-02-12 | 2004-02-06 | Magnetic resonance imaging apparatus and irregular magnetic field correction method |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| JP2004261591A JP2004261591A (en) | 2004-09-24 |
| JP2004261591A5 true JP2004261591A5 (en) | 2006-05-11 |
| JP4343726B2 JP4343726B2 (en) | 2009-10-14 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2004030577A Expired - Fee Related JP4343726B2 (en) | 2003-02-12 | 2004-02-06 | Magnetic resonance imaging apparatus and irregular magnetic field correction method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4343726B2 (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4763267B2 (en) * | 2004-11-08 | 2011-08-31 | 株式会社日立メディコ | Magnetic resonance imaging system |
| JP4969933B2 (en) * | 2006-07-18 | 2012-07-04 | 株式会社日立メディコ | Magnetic resonance imaging system |
| JP5502308B2 (en) * | 2007-12-20 | 2014-05-28 | 株式会社東芝 | Magnetic resonance imaging system |
| JP5883207B2 (en) * | 2007-12-28 | 2016-03-09 | 株式会社東芝 | Magnetic resonance imaging apparatus and control program for magnetic resonance imaging apparatus |
| JP5416960B2 (en) * | 2008-12-17 | 2014-02-12 | 株式会社東芝 | Magnetic resonance imaging system |
| JP5666779B2 (en) * | 2009-01-27 | 2015-02-12 | 株式会社東芝 | Magnetic resonance imaging system |
| JP5559506B2 (en) * | 2009-10-07 | 2014-07-23 | 株式会社日立メディコ | Magnetic resonance imaging apparatus and residual magnetic field suppression method |
| US9453897B2 (en) | 2010-08-26 | 2016-09-27 | Hitachi Medical Corporation | Magnetic resonance imaging apparatus and vibrational error magnetic field reduction method |
| JP2012183233A (en) | 2011-03-07 | 2012-09-27 | Toshiba Corp | Magnetic resonance imaging apparatus |
| JPWO2013002232A1 (en) * | 2011-06-30 | 2015-02-23 | 株式会社日立メディコ | Magnetic resonance imaging apparatus and method of measuring gradient magnetic field output waveform thereof |
| EP3581955A1 (en) * | 2018-06-12 | 2019-12-18 | Koninklijke Philips N.V. | Determination of higher order terms of the three-dimensional impulse response function of the magnetic field gradient system of a magnetic resonance imaging system |
| CN111623698B (en) * | 2020-05-22 | 2021-10-01 | 北京控制工程研究所 | Eddy current displacement sensor circuit with nonlinear correction function |
| CN113296037A (en) * | 2021-05-21 | 2021-08-24 | 电子科技大学 | High-field magnetic resonance gradient controller |
| CN114814684B (en) * | 2022-06-23 | 2022-09-16 | 中科微影(浙江)医疗科技有限公司 | Optimized imaging method, device, equipment and medium for small nuclear magnetic resonance equipment |
-
2004
- 2004-02-06 JP JP2004030577A patent/JP4343726B2/en not_active Expired - Fee Related
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