V-Shaped Gradient Coil Arrangement for MRI Stray Field Reduction

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Solution Overview

Problem

Current MRI systems face challenges with extensive stray magnetic fields, patient claustrophobia due to narrow tunnels, and restricted access for medical staff, which are not adequately addressed by existing magnet designs such as solenoid and C-shaped magnets.

Innovation Solution

A gradient system with pairs of gradient coils arranged at angles greater than 10° to create a V-shaped configuration, optimized for MRI systems with multiple examination areas, particularly those with toroidal magnetic fields, to produce spatially non-constant magnetic fields and improve spatial resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If solenoid or C-shaped magnets are used, then basic MRI functionality is achieved, but stray magnetic fields become extensive and require strict access control

Engineering Contradiction:
Improvestray magnetic field extentVSAvoidaccess control requirements
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The gradient system is divided into multiple independent gradient coil pairs arranged in a V-shape, with each pair contributing to specific gradient components. This segmentation allows optimized positioning of each coil pair to minimize stray fields while maintaining gradient performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The gradient coils are arranged in a V-shaped configuration with central planes at angles greater than 10° to each other, introducing angular dimensionality to the traditional linear arrangement. This dimensional change optimizes the magnetic field distribution and reduces stray field extent.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Shape

If solenoid magnets with narrow tunnels are used, then compact structure is achieved, but patient claustrophobia increases and medical staff access is restricted

Engineering Contradiction:
Improveexamination tunnel opennessVSAvoidmagnet structure complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The V-shaped gradient coil arrangement introduces asymmetric angular positioning (greater than 10° between central planes) to optimize the examination space geometry. This asymmetric configuration opens up the examination area while maintaining structural efficiency.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The V-shaped configuration with angled gradient coil pairs creates a more open, curved examination space compared to linear arrangements, reducing claustrophobic feelings while maintaining magnetic field homogeneity through geometric optimization.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Measurement precision

If gradient coils are arranged in traditional linear configuration, then simple construction is achieved, but spatial resolution and performance in toroidal field systems is suboptimal

Engineering Contradiction:
Improvespatial resolutionVSAvoidgradient coil arrangement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The V-shaped gradient coil arrangement with adjustable angular parameters (greater than 10° between central planes) provides dynamic adaptability to different toroidal field configurations, optimizing spatial resolution for multiple examination areas while maintaining construction feasibility.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The V-shaped gradient system enhances spatial resolution, reduces stray magnetic fields, and provides open access for patients, improving clinical workflow and reducing claustrophobic feelings, while maintaining mechanical robustness and efficiency.

Implementation Method 1

A gradient system for a magnetic resonance imaging system ('MRI-system'), especially for a MRI-system with two or more examination areas

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3828573A1V-shaped gradient system for a magnetic resonance imaging system
Publication Date: 2021.06.02 SIEMENS HEALTHINEERS AG
  • EP3828573A1 patent drawingFigure 1
  • EP3828573A1 patent drawingFigure 2
  • EP3828573A1 patent drawingFigure 3

AI summary

The invention describes a gradient system for a magnetic resonance imaging system comprising a number of pairs of gradient coils (25x, 25y, 25z), wherein the gradient coils (25x, 25y, 25z) of each pair comprise a central plane (23) and are arranged at opposite sides of an examination area (M1, M2, M3, M4, M5, M6) such that the central planes (23) of the two gradient coils (25x, 25y, 25z) of a pair are at an angle greater than 10° to another so that the gradient system (20) is V-shaped. The invention further describes a magnetic resonance imaging system with such gradient system.