MRI Coupling Coil SAR Conversion for Local Scan Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing magnetic resonance systems face challenges in accurately measuring local Specific Absorption Rate (SAR) values for local body sites during scans, as the SAR values monitored via electrical signals differ from the actual values when using wirelessly coupled coupling coils, leading to potential safety issues and inefficiencies.
Innovation Solution
A safety control method is implemented that involves obtaining real-time whole-body SAR values, determining a conversion coefficient, and converting it to local SAR values using electromagnetic field and mass density distributions to ensure safe scanning conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a coupling coil is used to excite a local volume wirelessly, then the ease of operation and adaptability for local imaging is improved, but the measurement precision of local SAR values deteriorates because the monitored SAR values differ from actual values
Solution Approach 1:
The patent introduces an electrical signal monitoring system as an intermediary to indirectly measure local SAR values. Since direct measurement in coupling coils is difficult, the system monitors electrical signals from the body coil that are coupled to the coupling coil, using these signals as a proxy to estimate local SAR values and ensure safety during scanning.
2Reliability
If real-time SAR monitoring is implemented, then the safety of the scanning process is improved, but the device complexity increases due to additional monitoring and conversion mechanisms
Solution Approach 1:
The patent makes the body coil serve multiple functions: it acts as both the primary transmitting coil for RF excitation and as a monitoring coil for measuring SAR values. By utilizing the existing body coil's electrical signals for both transmission and monitoring purposes, the system avoids adding separate monitoring hardware, thus reducing overall device complexity while maintaining safety monitoring capabilities.
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
Enables accurate real-time monitoring of local SAR values, preventing unsafe conditions by ensuring the magnetic resonance scan adheres to safety limits, thereby improving scan safety and efficiency.
Implementation Method 1
a coupling coil configured to receive the RF excitation pulse from the body coil to generate an RF field for exciting a local volume of a scanned subject
Data Source
AI summary
A magnetic resonance system and a safety control method for a magnetic resonance scan are provided. In the magnetic resonance scan, a local volume of a scanned subject is excited using a coupling coil, and the coupling coil is configured to receive a radio frequency (RF) excitation pulse from a body coil of the magnetic resonance system to generate an RF field for exciting the local volume. The safety control method includes: obtaining a whole-body SAR value monitored in real time, wherein the whole-body SAR value is obtained based on the body coil; determining a conversion coefficient during the magnetic resonance scan, and converting the current whole-body SAR value to a current local SAR value of the local volume based on the conversion coefficient; and determining a safety state of the magnetic resonance scan based on the current local SAR value.