MRI RF Coil Array Tuned to Spatial Field Variations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic resonance imaging (MRI) apparatuses face reduced sensitivity of RF coils when the static magnetic field's magnetic field strength changes spatially, as existing RF coils are tuned to specific resonance frequencies suitable only for uniform magnetic fields, limiting the range and accuracy of NMR signal reception.
Innovation Solution
The MRI apparatus employs multiple RF coils tuned to different frequencies corresponding to varying magnetic field strengths within the imaging space, allowing the imaging control unit to control each coil to receive NMR signals at specific frequencies, thereby improving sensitivity and expanding the range of signal reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single RF coil tuned to a specific resonance frequency is used, then the coil can operate effectively in a uniform magnetic field, but its sensitivity is reduced when the magnetic field strength changes spatially
Solution Approach 1:
The imaging space is divided into multiple regions with different magnetic field strengths, and each region is assigned a dedicated RF coil tuned to the corresponding resonance frequency. This segmentation allows each coil to operate optimally in its specific magnetic field region, resolving the contradiction between sensitivity and adaptability to non-uniform fields.
Solution Approach 2:
Different RF coils are positioned at different locations within the imaging space, with each coil having a resonance frequency specifically tuned to match the local magnetic field strength at its position. This local optimization ensures maximum sensitivity in each region while collectively covering the entire non-uniform magnetic field range.
2Measurement precision
If an RF coil is tuned to a specific resonance frequency, then it can achieve optimal performance at that frequency, but the range of NMR signal reception is limited
Solution Approach 1:
The system employs multiple RF coils that collectively provide universal coverage across a wide range of magnetic field strengths. Each coil is specialized for a specific frequency range, but the combination of all coils enables the system to receive NMR signals throughout the entire imaging space, achieving both precision and broad applicability.
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 the sensitivity of RF coils and widens the range of NMR signal reception, even in areas with non-uniform magnetic field strengths, leading to improved image quality and accuracy in MRI imaging.
Implementation Method 1
a static magnetic field magnet that generates a static magnetic field having a magnetic field strength that changes spatially
Implementation Method 2
receive a nuclear magnetic resonance signal generated from a subject by an influence of a radio frequency pulse transmitted to the subject
Data Source
AI summary
A magnetic resonance imaging apparatus according to an embodiment includes a static magnetic field magnet, a plurality of radio frequency coils, and processing circuitry. The static magnetic field magnet generates a static magnetic field having a magnetic field strength that changes spatially. The plurality of radio frequency coils receive a nuclear magnetic resonance signal generated from a subject by an influence of a radio frequency pulse transmitted to the subject, the subject being placed in the static magnetic field having a magnetic field strength that changes spatially. The processing circuitry controls each of the plurality of radio frequency coils to receive the nuclear magnetic resonance signal at each of a plurality of frequencies tuned according to at least a distribution of the static magnetic field.