MRI RF Pulse Phase Control for Parallel Sub-volume Excitation
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Solution Overview
Problem
Current MRI systems face challenges in efficiently generating high-resolution magnetic resonance images due to limitations in excitation and encoding techniques, which result in suboptimal signal acquisition and image quality.
Innovation Solution
The method involves applying first and second RF pulses with different phases and frequencies to simultaneously excite multiple sub-volumes, acquiring corresponding magnetic resonance signals, and generating image data using the sensitivities of multi-channel coils, with the data processing apparatus forming an inverse matrix to reconstruct high-resolution images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sub-volumes are simultaneously excited using RF pulses with different phases and frequencies, then image resolution and signal-to-noise ratio are enhanced, but the complexity of RF pulse design and data processing increases
Solution Approach 1:
The imaging volume is divided into multiple sub-volumes that are simultaneously excited using RF pulses with different phases and frequencies. Each sub-volume is encoded independently, allowing parallel acquisition of signal data from multiple regions, thereby enhancing image resolution without requiring sequential scanning of each region
Solution Approach 2:
RF pulses with varying phases and frequencies are applied to different sub-volumes to enable simultaneous excitation. The data processing apparatus utilizes sensitivity information and inverse matrix calculations to reconstruct high-resolution images from the acquired signals, transforming complex multi-parameter data into resolved image data
2Loss of time
If multiple sub-volumes are simultaneously excited, then scan time is reduced, but the complexity of signal acquisition and image reconstruction increases
Solution Approach 1:
Multiple sub-volumes are excited simultaneously using RF pulses with different phases and frequencies, enabling continuous acquisition of magnetic resonance signals from multiple regions in parallel. This continuous parallel acquisition significantly reduces the total scan time compared to sequential excitation methods
Solution Approach 2:
The data processing apparatus acts as an intermediary that receives complex signal data from multiple simultaneously excited sub-volumes and processes this data using sensitivity information and inverse matrix calculations to reconstruct high-resolution images, thereby managing the complexity of simultaneous signal acquisition
3Reliability
If RF pulses with different phases are applied to simultaneously excite multiple sub-volumes, then image quality is improved, but the complexity of multi-channel coil sensitivity measurement increases
Solution Approach 1:
Sensitivity information for each multi-channel coil with respect to RF pulses of different phases is pre-calculated and stored before actual image acquisition. This preliminary calculation of sensitivity matrices enables the system to handle complex multi-phase RF pulse applications without increasing real-time processing complexity during scanning
Solution Approach 2:
The system dynamically adapts to different RF pulse phases by utilizing pre-calculated sensitivity information corresponding to each phase. The data processing apparatus selects and applies the appropriate sensitivity matrix based on the applied RF pulse phase, enabling flexible and reliable image quality enhancement without requiring real-time sensitivity recalculation
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 image resolution and signal-to-noise ratio by grouping sub-volumes and optimizing RF pulse phases and frequencies, reducing scan time and improving image quality.
Implementation Method 1
An MRI system typically obtains an image of biological tissue of a human body by using a magnetic field generated by a magnetic force. The MRI system applies a high frequency signal to the biological tissue to generate a resonance phenomenon by molecules within the biological tissue.
Implementation Method 2
applying to a target first radio frequency (RF) pulses having phases and different frequencies to simultaneously excite a plurality of sub-volumes constituting a volume of the target
Data Source
AI summary
A method and apparatus for generating a magnetic resonance image including applying to a target first radio frequency (RF) pulses having phases and different frequencies to excite a plurality of sub-volumes constituting a volume of the target, and acquiring first magnetic resonance signals from the plurality of sub-volumes, and applying to the target second RF pulses having the same frequencies as the frequencies of the first RF pulses and phases at least one of which is different from the phases of the first RF pulses, and acquiring second magnetic resonance signals from the plurality of sub-volumes. Also, data may be generated based on the first and second magnetic resonance signals.