RF Transmit System Linearity Compensation for MRI
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Solution Overview
Problem
MRI systems face challenges in achieving high linearity of RF amplifiers, which is crucial for image quality, as existing solutions often compromise between efficiency and linearity, and prior linearity compensation methods are inadequate for clinical applications.
Innovation Solution
A novel RF transmit system that uses feedback signals and predetermined relationships to generate linearity compensation control signals, allowing for real-time adjustment of RF pulse signals to compensate for non-linearity, incorporating deep learning networks for optimal load characteristics and storing feedback signal-linearity compensation values in memory.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If high-power RF amplifiers are used to improve efficiency, then energy efficiency is improved, but linearity deteriorates due to non-linearity in gain and phase
Solution Approach 1:
The patent implements a feedback mechanism where the RF output unit receives feedback signals from the signal processing unit and generates linearity compensation control signals based on predetermined feedback signal-linearity compensation value relationships. This closed-loop feedback system continuously adjusts the RF pulse signal to compensate for non-linearity introduced by high-power RF amplifiers, enabling the system to maintain linearity while using high-efficiency amplifiers.
Solution Approach 2:
The patent changes the operational parameters of the RF amplifier by introducing linearity compensation control signals that adjust gain and phase parameters in real-time. The RF output unit modifies these parameters based on feedback signals and predetermined relationships, allowing the amplifier to operate in a non-linear region while maintaining overall system linearity through dynamic parameter adjustment.
2Manufacturing precision
If conventional linearity compensation methods are applied, then linearity is partially improved, but compensation precision is insufficient for clinical MRI applications
Solution Approach 1:
The patent employs a precise feedback mechanism where feedback signals from the signal processing unit are used to generate linearity compensation control signals. The feedback signal-linearity compensation value relationships are predetermined and stored, enabling high-precision lookup and compensation. This feedback-based approach achieves compensation precision sufficient for clinical MRI applications by continuously monitoring and adjusting RF pulse characteristics.
Solution Approach 2:
The patent replaces conventional mechanical or analog linearity compensation methods with a digital signal processing approach. The RF output unit uses digital feedback signals and predetermined digital relationships to generate compensation control signals, substituting precise digital computation for less accurate conventional methods. This digital substitution enables higher compensation precision required for clinical applications.
Data Source
AI summary
The present invention relates to an RF transmit system and method, MRI system and a pre-scan method and medium thereof. The RF transmit system comprises: an RF output unit, for generating and outputting an RF pulse signal; an RF amplifier, for amplifying the RF pulse signal; and a signal processing unit, for communicating the amplified RF pulse signal to an RF transmit coil of the MRI system and outputting a feedback signal to the RF output unit, wherein the RF output unit generates a linearity compensation control signal based on the feedback signal and a predetermined feedback signal-linearity compensation value-relationship, so as to carry out linearity compensation for the RF pulse signal outputted by the RF output unit. The RF transmit method corresponds to the above noted system and the MRI system comprises the above noted RF transmit system. The pre-scan method comprises the RF transmit method. Instructions recorded by the medium may execute the above noted RF transmit method and pre-scan method.