CN104730476A - Planar gradient coil for magnetic resonance microimaging - Google Patents
Planar gradient coil for magnetic resonance microimaging Download PDFInfo
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- CN104730476A CN104730476A CN201510090577.0A CN201510090577A CN104730476A CN 104730476 A CN104730476 A CN 104730476A CN 201510090577 A CN201510090577 A CN 201510090577A CN 104730476 A CN104730476 A CN 104730476A
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Abstract
Provided is a planar gradient coil assembly for magnetic resonance microimaging. A planar gradient coil is formed by a set of three micro planar gradient coil bodies in the orthogonal direction, and the planar gradient coil assembly sequentially comprises six planar coils of +-Gx, +-Gy and +-Gz from inside to outside from the geometric center of the coil structure, and the planar gradient coil assembly is achieved based on two opposite six-layer circuit boards.
Description
Technical field
The present invention relates to a kind of for the sterically defined plane gradient coil of magnetic resonance micro-imaging, especially there is three gradient directions, two-dimensional gradient field coil based on reverse Helmholtz coils.
Background technology
At present, in mr imaging technique field, have two kinds of magnets building strong static magnetic field, superconducting magnet and permanent-magnet, there is very big difference in both magnet structures and static magnetic field direction.Superconducting magnet is owing to being cylinder type, and the static magnetic field produced is along cylinder axis direction, and therefore corresponding gradient coil is implemented on the face of cylinder, and is joined the gradient magnetic produced on the orthogonal directions of three, space by coil cover.And pole plate is the permanent-magnet C type structure often of plane, static magnetic field direction is perpendicular to the plane at two pole plate places, correspondingly supporting gradient coil is plane, and the gradient magnetic of generation is consistent with static magnetic field direction, and magnetic field gradient directions has x, y and z equally to three kinds; The trend of winding wire is obtained by Target field approach and the design of stream function method usually.
When tiny sampler magnetic resonance imaging, the magnetic field gradient that original large scale gradient coil produces no longer is applicable to carrying out micro-imaging, grade is narrowed down to from meter level for sample yardstick, correspondingly magnetic field gradient value also will bring up to about 6500Gauss/cm from about 6.5Gauss/cm, thus the method for designing of traditional face of cylinder or plane pole plate type gradient coil is no longer applicable.In addition, determine gradient coil yardstick because sample yardstick is small small, then processing will be difficult to the coil that conventional target field and stream function approach design.
Patent of invention 2005800200242 " magnetic resonance imaging system with iron-assisted magnetic field gradient system ", disclose a kind of MR imaging apparatus, comprise main magnet (20), it is around inspection area (18) and the main field generated in inspection area; Magnetic field gradient system (30) is placed in the outside of main magnet.Its magnetic field gradient system complex structure, relates to the magnetic shielding measure between superconducting magnet; Especially, theoretical according to magnetic field analysis, the magnetic field that cylindrical coil produces is only applicable to the sample imaging with rotational symmetry feature, and for the objective body of two-dimension plane structure, the functional expansion mathematical model of cylinder or sphere is inapplicable.
Summary of the invention
The object of the invention is to overcome the deficiency that the whole body of prior art and position magnetic resonance imaging gradient coil can not carry out micro volume micro-imaging, propose a kind of micro plane-type gradient coil.Gradient coil of the present invention is by integrated with Minitype solenoid radio-frequency coil, and can carry out high-resolution magnetic resonance micro-imaging, the present invention may be used for superconducting magnet, also can be used for whole body permanent-magnet.
The technical solution adopted for the present invention to solve the technical problems is:
Plane gradient coil of the present invention is the miniature planar gradient coils set of one group of three orthogonal directions, uses multilayer printed circuit board manufacturing technology, realizes based on two pieces of 6 layer circuit boards staggered relatively.Described plane gradient coil groups from the geometric center of loop construction from inside to outside, is+-Gx ,+-Gy and+-Gz six gradient coils successively.
Two pieces of 6 layer circuit board thickness positioned opposite are identical, are defined as top board and base plate respectively.Gap is left between two piece of 6 layer circuit board.In 6 wiring layers of every block circuit board, top layer and bottom are for arranging line, and 3 centres are used for coil cabling.Base plate has-Gx gradient coil lead-in wire port ,-Gy gradient coil lead-in wire port, and-Gz gradient coil lead-in wire port.Top board has the lead-in wire port of+Gx gradient coil ,+Gy gradient coil and+Gz gradient coil.-Gx the gradient coil being positioned at base plate is composed in series by the x-axis negative sense subcoil of the x-axis forward subcoil and generation reversed magnetic field that produce forward magnetic field respectively,-Gy gradient coil is also be composed in series by the y-axis negative sense subcoil of the y-axis forward subcoil and generation reversed magnetic field that produce forward magnetic field, and-Gz gradient coil is a z-axis negative sense subcoil producing reversed magnetic field.+ Gx the gradient coil being positioned at top board is composed in series by the x-axis negative sense subcoil of the x-axis forward subcoil and reversed magnetic field that produce forward magnetic field respectively, + Gy gradient coil is also be composed in series by the y-axis forward subcoil and generation reversed magnetic field y-axis negative sense subcoil that produce forward magnetic field, and+Gz gradient coil is a z-axis forward subcoil producing forward magnetic field.
When passing to DC current, the x-axis forward subcoil of base plate-Gx gradient coil and the x-axis forward subcoil of top board+Gx gradient coil produce perpendicular to coil plane forward magnetic field upwards, and the x-axis negative sense subcoil of the x-axis negative sense subcoil of base plate-Gx gradient coil and top board+Gx gradient coil produces perpendicular to the downward reversed magnetic field of coil plane, top board+Gx gradient coil and base plate-Gx gradient coil along x-axis orientation, define x to magnetic field gradient; The y-axis forward subcoil of base plate-Gy gradient coil and the y-axis forward subcoil of top board+Gy gradient coil produce perpendicular to coil plane forward magnetic field upwards, and the y-axis negative sense subcoil of the y-axis negative sense subcoil of base plate-Gy gradient coil and top board+Gy gradient coil produces perpendicular to the downward reversed magnetic field of coil plane, top board+Gy gradient coil and base plate-Gy gradient coil along y-axis orientation, define y to magnetic field gradient; And the z-axis negative sense subcoil of-Gz gradient coil of base plate can produce perpendicular to the downward reversed magnetic field of coil plane, the direction in the forward magnetic field of the x-axis forward subcoil generation of+Gz gradient coil of top board perpendicular to coil plane upwards, then whole gradient coil geometric center produce z to magnetic field gradient, magnetic field, geometric center place is zero.Choosing of the spacing of top board and base plate two pieces of circuit boards is then should make the magnetic field of space distribution at x, y and z to all according to 1 rank linear variability law distribution.
The present invention achieves three direction orthogonal magnetic gradient fields based on micro-planar structure dexterously, and the lower surface of top board and the spacing of plate upper surface are 5 millimeters, because the distance between upper lower coil is suitable, improves the linearity in magnetic field.Again due to employing is reverse Helmholtz coil arrangement, and compare with target field/stream function approach, design complexities reduces greatly.
Accompanying drawing explanation
Below in conjunction with accompanying drawing, the present invention will be further described with concrete enforcement.
Fig. 1 is top board Gx gradient coil cabling schematic diagram of the present invention;
Fig. 2 is top board Gy gradient coil cabling schematic diagram of the present invention;
Fig. 3 is top board Gz gradient coil cabling schematic diagram of the present invention;
Fig. 4 is base plate Gx gradient coil cabling schematic diagram of the present invention;
Fig. 5 is base plate Gy gradient coil cabling schematic diagram of the present invention;
Fig. 6 is base plate Gz gradient coil cabling schematic diagram of the present invention;
Fig. 7 is the coil structure of top board of the present invention and base plate.
In figure: 1 top board produces the x-axis forward subcoil of+Gx gradient coil in forward magnetic field, 2 top boards produce the x-axis negative sense subcoil of+Gx gradient coil of reversed magnetic field, 5 top boards produce the y-axis forward subcoil of+Gy gradient coil in forward magnetic field, 6 top boards produce the y-axis negative sense subcoil of+Gy gradient coil of reversed magnetic field, 9 top boards produce the z-axis forward subcoil of+Gz gradient coil in forward magnetic field, 14 base plates produce the x-axis forward subcoil of-Gx gradient coil in forward magnetic field, 15 base plates produce the x-axis negative sense subcoil of-Gx gradient coil of reversed magnetic field, 18 base plates produce the y-axis forward subcoil of-Gy gradient coil in forward magnetic field, 19 base plates produce the y-axis negative sense subcoil of-Gy gradient coil of reversed magnetic field, 22 base plates produce the z-axis negative sense subcoil of-Gz gradient coil of reversed magnetic field, the electric current input pin of 3 top board+Gx gradient coils, the electric current output pin of 4 top board+Gx gradient coils, the electric current input pin of 7 top board+Gy gradient coils, the electric current output pin of 8 top board+Gy gradient coils, the electric current input pin of 10 top board+Gz gradient coils, the electric current output pin of 11 top board-Gz gradient coils, the electric current input pin of 12 base plate-Gx gradient coils, the electric current output pin of 13 base plate-Gx gradient coils, the electric current input pin of 16 base plate-Gy gradient coils, the electric current output pin of 17 base plate-Gy gradient coils, the electric current input pin of 20 base plate-Gz gradient coils, the electric current output pin of 21 base plate-Gz gradient coils.
Embodiment
The miniature planar gradient coils set of the present invention three orthogonal directions from the geometric center of loop construction from inside to outside, is+-Gx ,+-Gy and+-Gz six planar coils, as shown in Figure 7 successively.
Plane gradient coil groups of the present invention adopts two pieces of 6 layer circuit boards realizations positioned opposite.In 6 layers of wiring layer of every block circuit board, layer top layer wiring layer and bottom wiring layer are for line of walking, and in the middle of having 3, wiring layer is for coil cabling.In top board, the input and output pin of two Gx subcoils and correspondence thereof is positioned at this circuit board the 5th layer, the input and output pin of two Gy subcoils and correspondence thereof is positioned at this circuit board the 4th layer, and the Gz coil of top board and the input and output pin of correspondence thereof are positioned at the 3rd layer of this circuit board.In base plate, the input and output pin of two Gx subcoils and correspondence thereof is positioned at the 2nd layer, and the input and output pin of two Gy subcoils and correspondence thereof is positioned at the 3rd layer, and Gz coil and corresponding input and output pin thereof are positioned at the 4th layer.
The cabling of+Gx the gradient coil of top board of the present invention and the-Gx gradient coil of base plate is respectively shown in Fig. 1 and Fig. 4.As shown in Figure 1 and Figure 4, top board is three coils: the rhythmo structure that+Gx gradient coil ,+Gy gradient coil and+Gz gradient coil stack, and+Gx gradient coil and+Gy gradient coil are made up of two the sub-coils producing forward and negative sense magnetic field again respectively; + Gz gradient coil is formed to subcoil to the z producing forward magnetic field by one; Base plate in like manner, the rhythmo structure that-Gx gradient coil of serving as reasons ,-Gy gradient coil and-Gz gradient coil stack ,-Gx gradient coil and-Gy gradient coil are made up of two the sub-coils producing forward and negative sense magnetic field again respectively;-Gz gradient coil is made up of to subcoil the z that produces reversed magnetic field.
Generation x is accessed to the electric current of magnetic field gradient by the electric current input pin 3 of top board+Gx gradient coil, flow through the x-axis negative sense subcoil 15 of the x-axis forward subcoil 1 of+Gx gradient coil of top board, the x-axis negative sense subcoil 2 of+Gx gradient coil of top board, the electric current output pin 4 of top board+Gx gradient coil, the electric current input pin 12 of base plate-Gx gradient coil, the x-axis forward subcoil 14 of base plate-Gx gradient coil and base plate-Gx gradient magnetic successively, then drawn by the electric current output pin 13 of base plate-Gx gradient coil.
The cabling of+Gy the gradient coil of top board of the present invention and the-Gy gradient coil of base plate is respectively shown in Fig. 2 and Fig. 5.As shown in Figure 2 and Figure 5, generation y is accessed to the electric current of gradient magnetic by the electric current input pin 7 of top board+Gy gradient coil, flow through the y-axis forward subcoil 5 of+Gy gradient coil of top board successively, the y-axis negative sense subcoil 6 of top board+Gy gradient coil, the electric current output pin 8 of top board+Gy gradient coil, the electric current input pin 16 of base plate-Gy gradient coil, base plate produces the y-axis negative sense subcoil 19 of the y-axis forward subcoil 18 of-Gy gradient coil in forward magnetic field and the-Gy gradient coil of base plate generation reversed magnetic field, then drawn by the electric current output pin 17 of base plate-Gy gradient coil.
+ Gz the gradient coil of top board of the present invention and the cabling of base plate-Gz gradient coil is respectively shown in Fig. 3 and Fig. 6.As shown in Figure 3 and Figure 6, generation z is accessed to the electric current of gradient magnetic by the electric current input pin 10 of top board+Gz gradient coil, flow through successively top board+Gz gradient coil produce forward magnetic field z-axis produce the z-axis negative sense subcoil 22 of-Gz gradient coil of reversed magnetic field to subcoil 9, top board+Gy to the electric current input pin 20 of the electric current output pin 11 of gradient coil, base plate-Gz gradient coil and base plate, then drawn to the electric current output pin 21 of gradient coil by base plate z.
Figure 7 shows that the present invention comprises+-Gx ,+-Gy and+-Gz respectively organize the combination assumption diagram of gradient coil.When producing three direction gradient magnetics, top board is parallel with base plate staggered relatively, parallel distance between the lower surface of top board and plate upper surface is 5 millimeters, when passing to 1 Ampere currents, the spatial gradient magnetic field of 25 KHz/millimeter, 26 KHz/millimeter and 27 KHz/millimeter is produced respectively, for the location of Magnetic resonance imaging interior of articles in central area.
Claims (5)
1. a magnetic resonance micro-imaging plane gradient coil, it is characterized in that, described plane gradient coil is the miniature planar gradient coils set of one group of three orthogonal directions, described plane gradient coil groups from the geometric center of loop construction from inside to outside, be+-Gx ,+-Gy and+-Gz six planar coils successively, realize based on two pieces of 6 layer circuit boards staggered relatively.
2. according to magnetic resonance micro-imaging plane gradient coil according to claim 1, it is characterized in that, in described two pieces 6 layer circuit boards positioned opposite, the layer top layer wiring layer of every block circuit board and bottom wiring layer are for line of walking, and in the middle of 3, wiring layers are used for coil cabling; In top board, the input and output pin of two Gx subcoils and correspondence thereof is positioned at this circuit board the 5th layer, the input and output pin of two Gy subcoils and correspondence thereof is positioned at this circuit board the 4th layer, and the Gz coil of top board and the input and output pin of correspondence thereof are positioned at the 3rd layer of this circuit board; In base plate, the input and output pin of two Gx subcoils and correspondence thereof is positioned at the 2nd layer, and the input and output pin of two Gy subcoils and correspondence thereof is positioned at the 3rd layer, and Gz coil and corresponding input and output pin thereof are positioned at the 4th layer.
3. according to magnetic resonance micro-imaging plane gradient coil according to claim 2, it is characterized in that,-Gx the gradient coil being positioned at described base plate is composed in series by the x-axis negative sense subcoil of the x-axis forward subcoil and generation reversed magnetic field that produce forward magnetic field respectively,-Gy gradient coil is composed in series by the y-axis negative sense subcoil of the y-axis forward subcoil and generation reversed magnetic field that produce forward magnetic field, and-Gz gradient coil is a z-axis negative sense subcoil producing reversed magnetic field; + Gx the gradient coil being positioned at described top board is composed in series by the x-axis negative sense subcoil of the x-axis forward subcoil and reversed magnetic field that produce forward magnetic field respectively, + Gy gradient coil is also be composed in series by the y-axis forward subcoil and generation reversed magnetic field y-axis negative sense subcoil that produce forward magnetic field, and+Gz gradient coil is a z-axis forward subcoil producing forward magnetic field.
4. according to the magnetic resonance micro-imaging plane gradient coil described in Claims 2 or 3, it is characterized in that, when to often organize gradient coil pass to DC current time, the x-axis forward subcoil of base plate-Gx gradient coil and the x-axis forward subcoil of top board+Gx gradient coil produce perpendicular to coil plane forward magnetic field upwards, and the x-axis negative sense subcoil of base plate-Gx gradient coil and the x-axis negative sense subcoil of top board+Gx gradient coil produce perpendicular to the downward reversed magnetic field of coil plane; Top board+Gx gradient coil and base plate-Gx gradient coil, along x-axis orientation, define x to magnetic field gradient; The y-axis forward subcoil of base plate-Gy gradient coil and the y-axis forward subcoil of top board+Gy gradient coil produce perpendicular to coil plane forward magnetic field upwards, and the y-axis negative sense subcoil of base plate-Gy gradient coil and the y-axis negative sense subcoil of top board+Gy gradient coil produce perpendicular to the downward reversed magnetic field of coil plane; Top board+Gy gradient coil and base plate-Gy gradient coil, along y-axis orientation, define y to magnetic field gradient; The z-axis negative sense subcoil of-Gz gradient coil of base plate produces perpendicular to the downward reversed magnetic field of coil plane, the z-axis forward subcoil of+Gz gradient coil of top board produces perpendicular to coil plane forward magnetic field upwards, then whole gradient coil geometric center produce z to magnetic field gradient, magnetic field, geometric center place is zero.
5., according to magnetic resonance micro-imaging plane gradient coil according to claim 1, it is characterized in that, described top board parallel with base plate staggered relatively time, the lower surface of top board and the spacing of plate upper surface are 5 millimeters.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109613459A (en) * | 2018-12-06 | 2019-04-12 | 厦门大学 | The micro-fluidic plane gradient coil of superconducting pulse nuclear magnetic resonance chemical analyser and mounting bracket |
| CN110007259A (en) * | 2018-01-04 | 2019-07-12 | 布鲁克碧奥斯平股份公司 | NMR shimming system |
| WO2021028620A1 (en) * | 2019-08-12 | 2021-02-18 | Aalto University Foundation Sr | Devices and methods for influencing magnetic fields |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001000413A (en) * | 1999-06-21 | 2001-01-09 | Ge Yokogawa Medical Systems Ltd | Method for manufacturing gradient coil, gradient coil unit, gadient coil and mri equipment |
| CN1336558A (en) * | 2000-04-19 | 2002-02-20 | Ge医疗系统环球技术有限公司 | Method for measuring magnetic field, method for producing gradient coil, gradient coil and magnetic resonance imaging arrangement |
| CN101460860A (en) * | 2006-05-03 | 2009-06-17 | 普拉德研究及开发股份有限公司 | Downhole micro magnetic resonance analyzer |
| WO2011063342A1 (en) * | 2009-11-20 | 2011-05-26 | Viewray Incorporated | Self shielded gradient coil |
| CN102445674A (en) * | 2010-09-22 | 2012-05-09 | 特斯拉工程有限公司 | Gradient coil sub-assemblies |
| CN104134511A (en) * | 2014-07-22 | 2014-11-05 | 中国科学院电工研究所 | Zero magnetic space system device and adjustment method thereof |
| CN104267359A (en) * | 2014-10-20 | 2015-01-07 | 包头市稀宝博为医疗系统有限公司 | Gradient coil used for magnetic resonance imaging |
-
2015
- 2015-02-28 CN CN201510090577.0A patent/CN104730476A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001000413A (en) * | 1999-06-21 | 2001-01-09 | Ge Yokogawa Medical Systems Ltd | Method for manufacturing gradient coil, gradient coil unit, gadient coil and mri equipment |
| CN1336558A (en) * | 2000-04-19 | 2002-02-20 | Ge医疗系统环球技术有限公司 | Method for measuring magnetic field, method for producing gradient coil, gradient coil and magnetic resonance imaging arrangement |
| CN101460860A (en) * | 2006-05-03 | 2009-06-17 | 普拉德研究及开发股份有限公司 | Downhole micro magnetic resonance analyzer |
| WO2011063342A1 (en) * | 2009-11-20 | 2011-05-26 | Viewray Incorporated | Self shielded gradient coil |
| CN102445674A (en) * | 2010-09-22 | 2012-05-09 | 特斯拉工程有限公司 | Gradient coil sub-assemblies |
| CN104134511A (en) * | 2014-07-22 | 2014-11-05 | 中国科学院电工研究所 | Zero magnetic space system device and adjustment method thereof |
| CN104267359A (en) * | 2014-10-20 | 2015-01-07 | 包头市稀宝博为医疗系统有限公司 | Gradient coil used for magnetic resonance imaging |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110007259A (en) * | 2018-01-04 | 2019-07-12 | 布鲁克碧奥斯平股份公司 | NMR shimming system |
| CN109613459A (en) * | 2018-12-06 | 2019-04-12 | 厦门大学 | The micro-fluidic plane gradient coil of superconducting pulse nuclear magnetic resonance chemical analyser and mounting bracket |
| WO2021028620A1 (en) * | 2019-08-12 | 2021-02-18 | Aalto University Foundation Sr | Devices and methods for influencing magnetic fields |
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Application publication date: 20150624 |