Non-Concentric MR Receiver Coil Array for Shading Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-field magnetic resonance (MR) imaging systems face challenges in achieving uniform signal-to-noise ratio (SNR) due to RF-wave interference effects, leading to shading artifacts in MR images, particularly at higher magnetic field strengths, as patient size and shape affect RF fields, causing sensitivity variations across the image.
Innovation Solution
The implementation of a phased array coil system with non-concentric receiver coils, where the perimeter width of coils decreases along a specific direction, and coils are offset from each other to minimize inductive coupling and maintain SNR uniformity, reducing shading artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If equally sized coil elements are used in the receiver coil array, then the device complexity is reduced and manufacturing is simplified, but signal-to-noise ratio uniformity deteriorates causing shading artifacts in high-field MR imaging
Solution Approach 1:
The patent applies local quality by varying the size of individual coil elements within the array rather than using uniform sizes. Specifically, coil elements are designed with different dimensions to compensate for position-dependent signal variations, with larger coils placed in regions requiring higher sensitivity and smaller coils in regions where sensitivity is already sufficient. This non-uniform configuration optimizes SNR distribution across the imaging field while maintaining manufacturing feasibility through standardized fabrication processes adapted to different element sizes.
Solution Approach 2:
The invention employs asymmetry by deliberately creating an asymmetric arrangement of coil elements with varying sizes and positions. The coil array is configured with elements that have different perimeter widths and areas, arranged in a non-uniform pattern that counteracts the symmetric shading artifacts produced by conventional uniform arrays. This asymmetric design allows the system to compensate for patient-dependent RF field variations and achieve more uniform SNR across the imaging domain.
2Measurement precision
If high magnetic field strength (3 T or higher) is used, then imaging resolution and signal strength are improved, but RF-wave interference effects increase causing severe shading artifacts
Solution Approach 1:
The patent applies parameter changes by modifying the physical parameters of the coil elements, specifically their sizes and positions, to compensate for the increased RF-wave interference effects at high magnetic field strengths. The coil array is designed with elements having varying perimeter widths and areas, arranged to optimize signal reception while minimizing the impact of patient-dependent RF field variations. This parameter optimization allows the system to maintain high imaging resolution at 3 T and above while reducing shading artifacts.
3Device complexity
If conventional equally sized coil arrays are used, then device complexity is minimized, but image quality deteriorates due to shading effects that vary with patient size and shape
Solution Approach 1:
The patent implements local quality by tailoring the characteristics of individual coil elements to their specific positions within the array and the local RF field conditions. Each coil element's size and position are optimized for its specific location, with larger elements placed where greater signal sensitivity is needed and smaller elements where the RF field is already stronger. This localized optimization improves image quality consistency across different patient anatomies while maintaining a relatively simple overall array structure that can be manufactured and positioned routinely.
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 SNR uniformity across the image, minimizing shading effects and improving overall image quality by compensating for patient-dependent RF interference, especially at higher magnetic field strengths.
Implementation Method 1
A signal is emitted by the excited spins after the excitation signal B1 is terminated and this signal may be received and processed to form an image
Data Source
AI summary
A system for receiving MR data that includes an RF coil array for a magnetic resonance (MR) imaging apparatus. The RF coil array includes a plurality of non-concentric receiver coils arrayed along a first direction. A receiver coil at a first end of the RF coil array has a perimeter width greater than a perimeter width of a receiver coil at a second end of the RF coil array that is opposite from the first end along the first direction.