MRI Field Modification Resonators for SNR and SAR Control
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Solution Overview
Problem
Current MRI technologies face limitations in signal-to-noise ratio (SNR), imaging speed, and sensitivity to motion artifacts due to high magnetic field strengths, which are exacerbated by the specific absorption rate (SAR) of RF power and electromagnetic wave interference, particularly at higher field strengths.
Innovation Solution
A field modification device comprising resonator elements with individually controllable resonance frequencies and phases, which can dynamically modify the transmission and receive fields to enhance SNR and reduce the need for gradient magnetic fields, using energy harvesting and AI-based optimization techniques for improved imaging efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If higher magnetic field strengths are used to increase signal-to-noise ratio, then SNR improves, but tissue heating due to SAR increases quadratically
Solution Approach 1:
The patent applies local quality by using resonator elements with individually controllable resonance frequencies and phases to create localized field modifications. This allows SNR enhancement in specific regions of interest without uniformly increasing the magnetic field strength throughout the entire imaging volume, thereby avoiding proportional increases in SAR and tissue heating.
Solution Approach 2:
The patent changes the parameters of the magnetic field by dynamically adjusting the resonance frequencies and phases of resonator elements. This enables the system to modify field distribution characteristics rather than simply increasing overall field strength, achieving SNR improvement through parameter optimization rather than magnitude increase.
2Measurement precision
If higher magnetic field strengths are used, then SNR improves, but electromagnetic wave interference and motion artifacts increase
Solution Approach 1:
By implementing local field modifications through resonator elements positioned in specific locations, the patent enhances SNR in regions of interest while maintaining stable field characteristics in other areas. This localized approach reduces the formation of interference patterns across the entire imaging volume that would otherwise occur with uniform high field strength increases.
3Measurement precision
If gradient magnetic fields are used for spatial localization, then imaging capability is achieved, but imaging speed is substantially limited
Solution Approach 1:
The patent introduces resonator elements as intermediary components that assist in spatial encoding and signal detection. These resonator elements with controllable resonance frequencies and phases act as mediators between the main magnetic field and the detection system, enabling faster imaging by reducing the reliance on slow gradient switching for spatial localization.
4Measurement precision
If magnetic field strength is increased, then SNR improves, but gradient field switching times cannot be reduced
Solution Approach 1:
The patent segments the field modification function into multiple independently controllable resonator elements. This segmentation allows parallel control of multiple resonator elements with different resonance frequencies and phases, enabling faster field reconfiguration compared to traditional gradient switching, thereby reducing imaging time while maintaining SNR improvements.
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 device enhances SNR and imaging speed by locally reshaping the magnetic fields, reducing gradient field switching times, and minimizing tissue heating, thereby improving patient comfort and imaging quality without increasing magnetic field strength.
Implementation Method 1
a plurality of resonator elements being inducible by the transmission field and/or the receive field to resonate, thereby modifying the transmission field and/or the receive field
Implementation Method 2
using energy harvesting and AI-based optimization techniques for improved imaging efficiency
Data Source
AI summary
Methods, systems, and techniques for a field modification device for modifying a transmission field (Tx) and/or a receive field (Rx) used by an MR system are provided. The field modification device comprises a plurality of resonator elements being inducible by the transmission field and/or the receive field to resonate, thereby modifying the transmission field and/or the receive field, respectively, wherein a respective resonance frequency and/or resonance phase of a respective resonator element and/or of a respective group of resonator elements is individually controllable. The field modification device further comprises a device controller configured to individually control the respective resonance frequency and/or resonance phase of the respective resonator element and/or of the respective group of resonator elements.