US-12625208-B2 - Magnetic resonance system and gradient amplifier filter for magnetic resonance system

Abstract

The present invention relates to a magnetic resonance system and a gradient amplifier filter for a magnetic resonance system. The filter includes a plurality of non-magnetic core inductors and a printed circuit board having a multilayer structure, a plurality of filter capacitors being formed in a plurality of regions of the printed circuit board, respectively, wherein each non-magnetic core inductor is provided on the printed circuit board and spanning two of the plurality of filter capacitors.

Inventors

• Gang Ma
• Yanan Chen
• Tao He
• Haiyuan SUN
• Haoyang Gan

Assignees

• GE Precision Healthcare LLC

Dates

Publication Date

20260512

Application Date

20240710

Priority Date

20230726

Claims (13)

1. 1 . A gradient amplifier filter for a magnetic resonance system, comprising: a plurality of non-magnetic core inductors; and a printed circuit board having a multilayer structure, a plurality of filter capacitors being formed in a plurality of regions of the printed circuit board, respectively, wherein each non-magnetic core inductor is provided on the printed circuit board and spanning two of the plurality of filter capacitors.
2. 2 . The gradient amplifier filter according to claim 1 , characterized in that the printed circuit board comprises a plurality of stacked conductive layers, and a dielectric layer is provided between adjacent conductive layers, wherein the plurality of conductive layers comprise a plurality of signal layers and a plurality of ground layers arranged at intervals, the plurality of signal layers being connected together, each of the plurality of signal layers comprising a plurality of signal regions to form the plurality of filter capacitors with adjacent ground layers, and the plurality of signal regions of each signal layer being insulated from each other.
3. 3 . The gradient amplifier filter according to claim 2 , characterized in that a ground region is further formed on each signal layer, and the ground region of each signal layer is formed around the signal regions on the signal layer and is insulated from the signal regions.
4. 4 . The gradient amplifier filter according to claim 3 , characterized in that the ground region of each signal layer is electrically connected to the adjacent ground layers.
5. 5 . The gradient amplifier filter according to claim 1 , characterized in that the plurality of filter capacitors comprise a plurality of first capacitors formed side by side and a plurality of second capacitors formed side by side, the printed circuit board having symmetric first and second portions, the first portion comprising the plurality of first capacitors, the second portion comprising the plurality of second capacitors, the plurality of first capacitors and the plurality of second capacitors being opposite each other one to one, one of the plurality of non-magnetic core inductors spanning two adjacent first capacitors, and one of the plurality of non-magnetic core inductors spanning two adjacent second capacitors.
6. 6 . The gradient amplifier filter according to claim 5 , characterized in that areas of the plurality of first capacitors are different from each other, and areas of the plurality of second capacitors are different from each other.
7. 7 . The gradient amplifier filter according to claim 5 , characterized in that the distances between each two adjacent first capacitors are different, and the distances between each two adjacent second capacitors are different.
8. 8 . The gradient amplifier filter according to claim 2 , characterized in that two ends of each non-magnetic core inductor are each fixed by means of screws in regions in which two of the plurality of filter capacitors are located.
9. 9 . The gradient amplifier filter according to claim 8 , characterized in that a through hole for engaging with the screw is provided in a region of the printed circuit board in which each filter capacitor is located, the through hole passing through the plurality of conductive layers and the plurality of dielectric layers, an insulating region surrounding the through hole being provided on each ground layer, and the insulating region extending outwards from a hole wall of the through hole.
10. 10 . The gradient amplifier filter according to claim 1 , characterized in that each non-magnetic core inductor is an air core inductor.
11. 11 . The gradient amplifier filter according to claim 1 , characterized in that each non-magnetic core inductor comprises a flat conductive coil or a solenoid conductive coil.
12. 12 . The gradient amplifier filter according to claim 1 , characterized in that the filter is electrically connected to a gradient amplifier of the magnetic resonance system, and is arranged together with the gradient amplifier in a magnet housing of the magnetic resonance system.
13. 13 . A magnetic resonance system, comprising: a magnet housing in which a main magnet, a gradient coil, and a gradient amplifier are provided; and the gradient amplifier filter according to claim 1 , the filter comprising an input end connected to the gradient amplifier and an output end connected to the gradient coil.

Description

CROSS REFERENCE TO RELATED APPLICATIONS The present application claims priority and benefit of Chinese Patent Application No. 202310927658.6 filed on Jul. 26, 2023, which is incorporated herein by reference in its entirety. TECHNICAL FIELD The present invention relates to the field of medical imaging, and in particular to a magnetic resonance system and a gradient amplifier filter for a magnetic resonance system. BACKGROUND Magnetic resonance (MR) technology is one of the main imaging methods in modern medicine. A magnetic resonance system typically includes a gradient coil that interacts with a main magnetic field generated by a main magnet to generate a magnetic field gradient, so as to perform spatial position encoding of a magnetic resonance signal received from a human body, enabling reconstruction of an image of a body tissue on the basis of the encoded magnetic resonance signal. The gradient coil is usually close to the main magnet, e.g., integrated in a housing of a scanning device together with the main magnet, a cavity for accommodating a scan subject being formed in the housing. The scanning device having the main magnet and the gradient coil is provided in a scan room, and the scan room and an equipment room are each separate building spaces physically spaced apart from each other. The gradient coil typically requires a large drive current, and the drive current is provided via a gradient amplifier. In the prior art, the gradient amplifier is provided in the equipment room. One reason is that the accommodating space of the magnet housing in the scan room is limited, and another reason is that when the gradient amplifier and a component connected thereto are close to the main magnet, magnetic saturation may occur due to the influence of the main magnetic field, thereby seriously affecting imaging quality. SUMMARY One aspect of the present invention provides a gradient amplifier filter for a magnetic resonance system, comprising a plurality of non-magnetic core inductors and a printed circuit board having a multilayer structure, a plurality of filter capacitors being formed in a plurality of regions of the printed circuit board, respectively, wherein each non-magnetic core inductor is provided on the printed circuit board and across two of the plurality of filter capacitors. Another aspect of the present invention provides a magnetic resonance system, comprising a magnet housing and the gradient amplifier filter described above, a main magnet, a gradient coil and a gradient amplifier being provided in the magnet housing, and the filter comprising an input end connected to the gradient amplifier and an output end connected to the gradient coil. It should be understood that the brief description above is provided to introduce, in a simplified form, concepts that will be further described in the detailed description. The brief description above is not meant to identify key or essential features of the claimed subject matter. The scope is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any deficiencies raised above or in any section of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be better understood by reading the following description of non-limiting examples with reference to the accompanying drawings, wherein FIG. 1 shows a schematic structural diagram of an exemplary magnetic resonance system 100 according to some embodiments; FIG. 2 shows a schematic structural diagram of a magnetic resonance system 200 according to some embodiments of the present invention; FIG. 3 shows a schematic structural diagram of a gradient amplifier filter according to some embodiments of the present invention; FIG. 4 shows a sectional view of a printed circuit board in FIG. 3; FIG. 5 shows a schematic structural diagram of a signal layer of the printed circuit board in FIG. 4; FIG. 6 shows an equivalent circuit diagram of the gradient amplifier filter in FIG. 3; FIG. 7 and FIG. 8 respectively show different winding methods of a coil of a non-magnetic core inductor in FIG. 3; FIG. 9 shows a plurality of through holes provided on the printed circuit board in FIG. 3; and FIG. 10 and FIG. 11 each show a schematic diagram of an attenuation test performed on a gradient amplifier filter according to an embodiment of the present invention, wherein FIG. 10 shows a result of a common mode attenuation test, and FIG. 11 shows a result of a differential mode attenuation test. Together with the following description, the accompanying drawings illustrate and explain structural principles, methods, and principles described herein. In the accompanying drawings, the thickness and dimensions of the components may be enlarged or otherwise modified for clarity. Well-known structures, materials, or operations are not shown or described in detail to avoid obscuring the components and systems descri