MRI Antenna Apparatus Using High Permittivity Material Inversion

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current MRI systems using high permittivity materials (HPMs) in RF coils face limitations in B1 field efficiency and specific absorption rate (SAR) when the HPMs are positioned between the subject and the RF coil, affecting signal-to-noise ratio and scan time.

Innovation Solution

The antenna apparatus for RF coils in MRI systems incorporates a high permittivity material with a specific shape, positioning the antenna between the HPM and the subject, which improves B1 field efficiency and reduces SAR by optimizing the geometry of the HPM and antenna configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If HPM is positioned between the subject and the RF coil, then B1 field efficiency is improved, but SAR increases

Engineering Contradiction:

ImproveB1 field efficiencyVSAvoidSAR

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

The patent inverts the conventional HPM positioning by placing the antenna between the HPM and the subject rather than positioning the HPM directly against the subject. This inversion allows the HPM to enhance B1 field efficiency while the antenna acts as an intermediary that prevents excessive SAR accumulation at the subject interface.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The antenna serves as an intermediary element positioned between the HPM and the subject. This mediator allows the HPM to exert its field-enhancing effect while preventing direct harmful interaction between the HPM and the subject, thereby reducing SAR while maintaining B1 efficiency.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If HPM is positioned between the subject and the RF coil, then signal-to-noise ratio is improved, but SAR increases

Engineering Contradiction:

Improvesignal-to-noise ratioVSAvoidSAR

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent inverts the conventional HPM positioning by placing the antenna between the HPM and the subject rather than positioning the HPM directly against the subject. This inversion allows the HPM to enhance signal-to-noise ratio while the antenna acts as an intermediary that prevents excessive SAR accumulation at the subject interface.

Inventive Principle:

Principle #13The other way round (Inversion)

3Power

If HPM is positioned between the subject and the RF coil, then transmit efficiency is improved, but safety decreases due to increased SAR

Engineering Contradiction:

Improvetransmit efficiencyVSAvoidsafety

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The patent inverts the conventional HPM positioning by placing the antenna between the HPM and the subject rather than positioning the HPM directly against the subject. This inversion allows the HPM to enhance transmit efficiency while the antenna acts as an intermediary that prevents excessive SAR accumulation at the subject interface.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

Inventive Principle:

Principle #24Intermediary (Mediator)

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

This configuration enhances B1+ efficiency and reduces SAR, leading to improved signal transmission and reception in MRI systems, particularly at ultra-high field strengths, while maintaining safety and efficiency.

Implementation Method 1

a high permittivity material (HPM) having a shape and an antenna coupled to the HPM and positioned on the proximal surface such that the antenna is positioned between the HPM and the subject

Methodology Applied

Scientific EffectHigh permittivity material (HPM) effect: Dielectric Permittivity

Data Source

PatentUS11543475B2Antenna apparatus including high permittivity materials (HPM) for radio frequency (RF) coils

Publication Date: 2023.01.03 REGENTS OF THE UNIVERSITY OF MINNESOTA

AI summary

An antenna apparatus for a radio frequency (RF) coil to transmit signals to and to receive signal from a subject in a magnetic resonance imaging (MRI) system includes a distal surface facing away from the subject, a proximal surface facing towards the subject, a high permittivity material (HPM) having a shape, and an antenna coupled to the HPM and positioned on the proximal surface such that the antenna is positioned between the HPM and the subject.