Parallel Transmit RF Coil for Simultaneous Multi-Slice MRF Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional MRI techniques require repetitive pulse sequences and skilled interpretation for disease diagnosis, limiting efficiency and consistency across different machines and configurations, while Magnetic Resonance Fingerprinting (MRF) aims to accelerate acquisition by varying sequence blocks to characterize tissue properties.
Innovation Solution
The integration of MRF with simultaneous multi-slice (SMS) techniques using a parallel transmit (pTX) array, where transmit channels are temporarily varied to capture an entire field of view of multiple slices with an MRF pulse sequence, enabling efficient characterization of tissue properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional MRI pulse sequences are used with repetitive preparation phases, then qualitative images with specific weightings can be produced, but acquisition time is extended and productivity is reduced
Solution Approach 1:
The patent employs periodic variation of RF pulse flip angles and sequence parameters in an MRF acquisition scheme, where different tissue types produce distinctive signal evolution patterns over time. This periodic action allows simultaneous characterization of multiple tissue properties (T1, T2, proton density) in a single acquisition, eliminating the need for repetitive conventional pulse sequences while maintaining measurement precision through pattern recognition and dictionary matching algorithms
2Productivity
If MRF techniques are used to accelerate acquisition, then productivity is improved, but device complexity increases due to varied sequence blocks and signal processing requirements
Solution Approach 1:
The patent implements dynamic adjustment of RF pulse parameters including flip angle variations, phase cycling, and gradient modulation within the MRF sequence. These dynamic parameter changes create unique signal fingerprints for different tissue types, enabling accelerated acquisition while managing complexity through systematic parameter modulation rather than requiring multiple static sequences
Solution Approach 2:
The MRF reconstruction process incorporates feedback through iterative dictionary matching and signal evolution comparison, where acquired signals are continuously compared against pre-calculated tissue-specific evolution patterns. This feedback mechanism enables automatic tissue classification and parameter mapping, reducing the need for manual interpretation and simplifying the overall system operation despite the complex underlying physics
3Productivity
If simultaneous multi-slice techniques are combined with MRF using pTX array, then productivity is improved by capturing multiple slices, but device complexity increases
Solution Approach 1:
The patent divides the imaging volume into multiple slices that are simultaneously excited using independent transmit channels of the pTX array. Each transmit channel can be independently controlled to target specific slice locations, allowing parallel acquisition of multiple slices without interference. This segmentation approach enables the system to capture entire fields of view of multiple slices simultaneously, dramatically improving productivity while managing complexity through channel-specific control
Solution Approach 2:
The pTX array system provides multi-functionality by enabling simultaneous multi-slice excitation, selective slice targeting, and flexible MRF sequence implementation across multiple anatomical regions. The same hardware infrastructure supports various imaging configurations and parameter combinations, making the system universally applicable to different clinical scenarios without requiring additional specialized equipment
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 approach enhances the efficiency of MRF imaging by allowing simultaneous multi-slice acquisition with minimal aliasing, improving the accuracy and consistency of tissue characterization across different imaging configurations.
Implementation Method 1
a parallel transmit radio frequency (RF) coil array
Implementation Method 2
Characterizing tissue species using nuclear magnetic resonance ('NMR') can include identifying different properties of a resonant species
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Systems and methods are provided for acquiring imaging data from one or more resonance species that simultaneously produce individual magnetic resonance signals in a plurality of different slices. The data is acquired by simultaneously exciting, using a pTX RF coil array, a plurality of different slices such that at least some of the plurality of different slices are excited by transmitting RF energy from a subset of transmit channels in the pTX RF coil array. The method also includes comparing the data to a dictionary of signal evolutions to determine quantitative values for two or more parameters of the resonant species based, at least in part, on matching the data to a set of known signal evolutions stored in the dictionary. The method includes producing an image for each of the plurality of different slice locations, at least in part, on the quantitative values.