Full-open permanent magnetism magnetic body for magnetic resonance image-forming

A magnetic resonance imaging, open technology, applied in applications, permanent magnets, measurement of magnetic variables, etc., can solve problems affecting the stability and uniformity of the magnetic field working area, adverse effects of magnetic field uniformity, and easy vibration of magnetic poles. Achieve the effect of improving the uniformity and stability of the magnetic field, improving the shimming efficiency, and reducing the total weight

Active Publication Date: 2008-06-04
BEIJING WANDONG MEDICAL TECH CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] 2) The structure of the C-type magnet is asymmetrical, which makes the magnetic field on the side close to the vertical yoke in the working area smaller, which adversely affects the uniformity of the magnetic field
[0009] 3) The C-shaped yoke makes the upper permanent magnet main pole a cantilever structure. When the equipment is disturbed by the outside world or its own machinery, the magnetic pole is more likely to vibrate, which affects the stability and uniformity of the magnetic field working area
[0010] 4) Due to the high stress requirements inside the upper yoke, steel with higher strength is generally used, but the magnetic permeability of steel is not high, so there is a higher requirement for the cross-sectional area of ​​the yoke, resulting in the The volume is too large, which ends up making the total weight of the magnet very large

Method used

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  • Full-open permanent magnetism magnetic body for magnetic resonance image-forming
  • Full-open permanent magnetism magnetic body for magnetic resonance image-forming
  • Full-open permanent magnetism magnetic body for magnetic resonance image-forming

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0059] In this embodiment, the static magnetic field strength of the magnetic resonance imaging working area is 4000 Gauss, the main magnetic pole material is NdFeB rare earth permanent magnet, and the rest of the magnet is made of electrical pure iron. The main dimensions of the magnet main structure are: total height 1900mm, length 2800mm, width 650mm, the shortest distance between the two vertical yokes 1a and 1b is 1900mm, the shortest distance between the two horizontal yokes 2a and 2b is 1100mm, the upper and lower pole rings The distance between them is 450mm, the diameter of 10 balls in the working area is 400mm, the uniformity of the magnetic field is less than 20ppm, and the total weight of the magnet is less than 16 tons.

[0060] Such as figure 1 as shown, figure 1 It is an appearance view of a fully open permanent magnet for magnetic resonance imaging according to the first embodiment of the present invention. The upper and lower horizontal yokes 2a, 2b are para...

Embodiment 2

[0072] In this example, refer to Figure 7 and Figure 8 Be explained. in, Figure 7 It is an appearance diagram of a fully open permanent magnet for magnetic resonance imaging according to the second embodiment of the present invention, Figure 8 It is a front view of a fully open permanent magnet for magnetic resonance imaging according to the second embodiment of the present invention. The specific magnet structure is similar to that of Embodiment 1, and only the upper part will be described here.

[0073] Part of the material is removed from the side of the middle part of the transverse yoke 2a away from the main magnetic pole 3a, and the transverse yoke after material removal still maintains a left-right and front-back symmetry. Viewed from the front, after part of the material is removed, the upper surface of the middle part of the transverse yoke 2a (that is, the surface away from the main magnetic pole side) forms a trapezoidal depression, the inner bottom edge is ...

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Abstract

The invention discloses a full-open permanent magnet for MRI, wherein the permanent magnet comprises: full-open main structure of a rectangular structure composed of two vertical yokes arranged left and right symmetrically and two transverse yokes arranged up and down symmetrically with an air gap zone of the permanent magnetic positioned in the middle of the full-open main structure; up and down two parallel opposite main poles which are respectively arranged on the sides close to the air gap zone of and connected with the up and down two transverse yokes; and up and down two parallel opposite pole plates which are respectively arranged on the sides close to the air gap zone of and connected with the up and sown two main poles. The invention enormously reduces the weight of the yokes, improves the shimming efficiency and increases the openness of the magnetic field.

Description

technical field [0001] The invention relates to the technical field of permanent magnets used for medical diagnosis in medical instruments, in particular to a fully open permanent magnet for magnetic resonance imaging. Background technique [0002] Magnetic resonance imaging (MRI) equipment is a medical diagnostic equipment developed since the 1980s. It non-invasively acquires images of arbitrary sections of various parts of the human body, can obtain clear soft tissue images, and obtain human anatomical information. And the most advanced clinical diagnostic equipment for diagnosing early cancer and various other diseases are valued in the international medical and technical circles. [0003] The magnet is one of the core equipment of the magnetic resonance imaging equipment, and its various performance indicators are directly related to the signal-to-noise ratio of the magnetic resonance equipment system, and determine the quality of the image to a certain extent. Magnets ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01R33/383A61B5/055H01F7/02
Inventor 王为民唐昕周德开李培张海涛
Owner BEIJING WANDONG MEDICAL TECH CO LTD
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