RF Coil Array Mode Compression for Parallel MRI
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current parallel transmission MRI systems are limited by the number of available RF transmit channels, which restricts the ability to utilize the spatial encoding power of RF coil arrays, leading to reduced acceleration capabilities and increased costs in expanding the number of transmit channels.
Innovation Solution
A sparsity-enforced method is employed to select a subset of spatial modes in the RF coil array, allowing for the formation of a user-defined RF excitation pattern by penalizing nonzero mode energies, thereby optimizing the connection of RF transmitters to coil elements and improving k-space trajectory acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of RF transmit channels is increased to utilize the spatial encoding power of RF coil arrays, then the acceleration capability and encoding efficiency are improved, but the system cost and complexity increase
Solution Approach 1:
The patent extracts and utilizes only the essential spatial encoding information from the coil array by performing eigenmode decomposition to identify the dominant encoding modes. Instead of using all available channels, it selects a reduced subset of channels that provide the necessary encoding capability, thereby reducing system complexity while maintaining acceleration performance
Solution Approach 2:
The patent makes the RF transmit system multi-functional by enabling a reduced number of transmit channels to perform the spatial encoding function that would traditionally require more channels. Through adaptive channel selection and eigenmode-based encoding, the system achieves both transmission and spatial encoding functions with fewer channels, reducing complexity while maintaining productivity
2Manufacturing precision
If the number of RF transmit channels is increased to achieve high-fidelity RF excitation patterns, then the excitation quality is improved, but the system cost increases
Solution Approach 1:
The patent changes the operational parameters of the transmit system by dynamically selecting which channels are active based on the specific excitation pattern requirements. Through adaptive channel allocation and eigenmode decomposition, the system adjusts the number and configuration of active transmit channels to match the minimum required for achieving the desired excitation quality, thereby maintaining high fidelity while reducing system complexity and cost
3Device complexity
If a reduced number of transmit channels is used, then the system cost and complexity are reduced, but the ability to utilize spatial encoding power is limited
Solution Approach 1:
The patent applies local quality by optimizing the specific configuration of the reduced number of transmit channels based on the spatial distribution requirements of the encoding task. Through eigenmode decomposition and adaptive channel selection, each remaining channel is optimally configured to maximize its contribution to spatial encoding in specific regions, thereby preserving essential spatial encoding power despite having fewer channels
Solution Approach 2:
The patent replaces the mechanical approach of simply adding more physical channels with a computational approach using eigenmode decomposition and adaptive channel selection. This substitution allows the system to extract and utilize the essential spatial encoding information through mathematical processing, preserving encoding power without proportionally increasing the number of physical channels
Data Source
AI summary
A method for target-dependent, sparsity-enforced selection for choosing a substantially optimal connection of radiofrequency (“RF”) transmitters to the elements of the RF coil array is provided. In particular, a method is provided that selects the linear combinations of the “N” spatial mode profiles of a transmission RF coil array, such that the k-space trajectory and pulse duration acceleration capabilities of the array are advantageously utilized. A sparsity-enforcement method that determines a subset of the available spatial modes for a parallel transmission RF coil array is employed to this end. In this manner, the utilization of the encoding power of a highly-parallel N-mode coil array in a system with only “P” available excitation channels is enabled.