Method for adjusting static magnetic field homogeneity, static magnetic field generation device for magnetic resonance imaging, magnetic field adjustment system, and program

一种调整方法、磁场调整的技术，应用在测量装置、应用、测量磁变量等方向，能够解决作业性差等问题，达到改善作业性、降低劳力、缩短工序的效果

Active Publication Date: 2013-12-11
HITACHI HEALTHCARE MFG LTD
View PDF7 Cites 21 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In addition, in the technology described in Patent Document 2, it is necessary to install or remove the second iron shim at the rear stage on the tray (base) on which the first iron shim has been arranged at the front stage, so there is also a problem of poor workability. question

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for adjusting static magnetic field homogeneity, static magnetic field generation device for magnetic resonance imaging, magnetic field adjustment system, and program
  • Method for adjusting static magnetic field homogeneity, static magnetic field generation device for magnetic resonance imaging, magnetic field adjustment system, and program
  • Method for adjusting static magnetic field homogeneity, static magnetic field generation device for magnetic resonance imaging, magnetic field adjustment system, and program

Examples

Experimental program
Comparison scheme
Effect test

no. 1 Embodiment approach

[0106] As one embodiment of the static magnetic field generator of the present invention, a cylindrical static magnetic field generator suitable for use in a horizontal magnetic field type MRI apparatus will be described.

[0107] exist Figure 7 An example of a cylindrical static magnetic field generator is shown in . The illustrated static magnetic field generating device 10 is composed of a cylindrical superconducting magnet 1 and a shim tray storage portion 3 arranged along the inner wall surface of the cylindrical bore 2 of the magnet 1 . The superconducting magnet 1 is composed of a solenoid-type superconducting coil (not shown) and a vacuum container 5 for housing the superconducting coil, and forms a substantially spherical uniform magnetic field space S in the cylindrical bore 2 . This magnetic field space S serves as an imaging space in which an inspection object is placed in the MRI apparatus.

[0108] When the static magnetic field generator 10 is used in an MRI ...

change example 1

[0116] exist Figure 8 In the above, as the two types of shim trays 31 and 32 , the case where shim trays having the same shape are used except for the positions and numbers of recesses is shown, but the shapes can also be changed depending on the type of shim trays. exist Figure 9 Embodiments with different shapes of shim trays are shown in .

[0117] Figure 9 The shim tray shown is also compatible with Figure 8 The same thing as the shim tray is that it is composed of the first and second shim trays 35, 36; recesses are uniformly formed in the longitudinal direction of the first shim tray 35, and the second shim tray 36 is only formed in the longitudinal direction. Both end portions in the side direction and the central portion form recesses. Figure 9 Among the shim trays, the area of ​​the cross section perpendicular to the longitudinal direction of the second shim tray 36 is smaller than that of the first shim tray 35, and the size of the recess is also smaller, an...

change example 2

[0121] Such as Figure 10 As shown, this modified example is characterized in that the second shim tray (shim tray for low-order item correction) 37 has an elongated cavity 38 in which a rod-shaped shim iron (shim rod) is inserted instead of a recess. A plurality of cavities 38 are formed along the longitudinal direction of the shim tray 37 . Arrange the spacer rod at the position determined by the magnetic field adjustment method. As a method of arranging the spacer rod, for example, the following method is adopted: the inner wall of the cavity 38 is formed into an internal thread, the outer peripheral surface of the spacer rod is formed into an external thread, and the spacer rod is fixed with the front end of a predetermined jig, while the spacer The rod rotates while moving until it reaches the specified position.

[0122] By forming a plurality of cavities, if the magnetic force cannot be satisfied by placing a shim iron in one cavity, it is possible to finely adjust th...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

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 a 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 component among 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.

Description

technical field [0001] The present invention relates to a static magnetic field generator using a superconducting magnet, and more particularly to a technique for adjusting the magnetic field uniformity of a static magnetic field generator for magnetic resonance imaging (MRI). Background technique [0002] In MRI, in order to obtain a high-quality MRI image, the uniformity of the static magnetic field height and high magnetic field are required in the static magnetic field generator. For these requirements, superconducting magnets are currently generally used. [0003] The uniformity of the magnetic field is mainly designed through the arrangement position of the superconducting coil, so that the required uniform magnetic field is generated in the desired space, but in fact, due to the manufacturing size error of the superconducting magnet, it is difficult to obtain the desired uniformity of the magnetic field. The static magnetic field generating unit includes a magnetic f...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): A61B5/055
CPCG01R33/3873G01R33/3802
Inventor 榊原健二
Owner HITACHI HEALTHCARE MFG LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap