MRI RF Pulse Adaptation to B1 Limits for Faster Imaging
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Solution Overview
Problem
Existing MRI systems face limitations in optimizing RF pulse design due to constraints on the B1 maximum value, leading to underutilization of RF power amplifiers and suboptimal image quality and scanning time.
Innovation Solution
Adjusting the RF pulse profile based on the real-time B1 maximum value to fully utilize the RF power amplifier, optimizing the waveform, and enhancing excitation or spin echo profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the B1 maximum value is constrained, then the RF power amplifier capability is limited, but the image quality and scanning time are suboptimal
Solution Approach 1:
The patent applies dynamics by making the RF pulse profile adjustable and adaptive. The system dynamically adjusts the RF pulse profile based on the actual B1 maximum value measured during scanning, allowing the RF power amplifier to operate at optimal levels rather than being constrained by fixed limitations. This dynamic adjustment resolves the contradiction by enabling full utilization of RF power amplifier capability while maintaining image quality.
Solution Approach 2:
The patent changes the parameter of RF pulse profile based on the measured B1 maximum value. By adjusting the RF pulse profile parameter according to the actual B1 field strength, the system optimizes the excitation conditions and improves both the utilization of RF power amplifier capability and image quality, resolving the technical contradiction between power capability and imaging performance.
2Productivity
If the RF pulse profile is not optimized, then the scanning time is extended, but the image quality remains suboptimal
Solution Approach 1:
The patent implements feedback by measuring the actual B1 maximum value during the scanning process and using this information to adjust the RF pulse profile. This closed-loop feedback mechanism ensures that the RF pulse is continuously optimized based on real-time conditions, reducing scanning time while maintaining or improving image quality.
Solution Approach 2:
The system dynamically adjusts the RF pulse profile based on real-time B1 maximum value measurements. This dynamic optimization allows the scanning process to adapt to actual conditions, reducing unnecessary scanning time while preserving image quality through continuous profile adjustment.
3Ease of operation
If the RF power amplifier is not fully utilized, then the system is simpler to operate, but the image quality and scanning efficiency are reduced
Solution Approach 1:
The system performs self-service by automatically measuring the B1 maximum value and adjusting the RF pulse profile without requiring manual intervention. The system self-optimizes its performance by autonomously adapting the RF pulse parameters based on measured conditions, thereby improving scanning efficiency while maintaining ease of operation through automation.
Solution Approach 2:
The patent automatically changes the RF pulse profile parameter based on the measured B1 maximum value. This automated parameter adjustment allows the system to fully utilize the RF power amplifier capability without complicating the operation interface, as the optimization occurs through automated measurement and adjustment processes rather than manual control.
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
Improves image quality and reduces scanning time by fully utilizing the RF power amplifier's capability and optimizing the RF pulse waveform.
Implementation Method 1
MRI utilizes the main magnet to generate a static magnetic field B0, and when a subject to be examined is located in the static magnetic field B0, nuclear spins associated with hydrogen nuclei in tissues of the subject to be examined are polarized
Implementation Method 2
nuclear spins associated with hydrogen nuclei in tissues of the subject to be examined are polarized, so that the tissue to be examined macroscopically generates a longitudinal magnetization vector
Implementation Method 3
The RF transmit coil transmits an RF field B1 orthogonal to the field B0 to the subject to excite atomic nuclei in the aforementioned resonant region to generate a transverse magnetization vector
Implementation Method 4
The high-power RF signal may be inputted to the RF transmit coil via an RF transmission line, so that the RF transmit coil transmits an RF field B1 orthogonal to the field B0 to the subject to excite atomic nuclei in the aforementioned resonant region
Implementation Method 5
After the RF field B1 is removed, the transverse magnetization vector is attenuated in a spiral manner, and a magnetic resonance signal is generated
Implementation Method 6
the transverse magnetization vector is attenuated in a spiral manner, and a magnetic resonance signal is generated. The magnetic resonance signal can be acquired for reconstructing an image of a tissue part to be examined
Data Source
AI summary
A magnetic resonance imaging method and a magnetic resonance imaging system are provided. The method includes: determining a B1 maximum value of a radio-frequency (RF) field; adjusting a profile of an RF pulse according to the B1 maximum value; and generating and transmitting an adjusted RF pulse, acquiring a magnetic resonance signal, and reconstructing a magnetic resonance image according to the magnetic resonance signal.