3D Gradient Echo Sequence Noise Optimization
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Solution Overview
Problem
3D gradient echo sequences in magnetic resonance systems produce high noise due to rapid gradient changes and high slew rates, making them uncomfortable for patients and requiring high gradient performance, which is not optimal for all systems.
Innovation Solution
Optimization of the 3D gradient echo sequence by adjusting parameters such as excitation pulse duration, k-space line order, and readout direction to minimize slew rates, amplitudes, and polarity changes, allowing for reduced gradient system requirements and noise reduction without altering echo time, bandwidth, or measurement time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gradient echo sequence uses rapid gradient switching to achieve fast imaging, then imaging speed and resolution are improved, but noise level increases significantly
Solution Approach 1:
The patent applies preliminary action by pre-calculating and pre-ordering the k-space traversal path before the actual imaging acquisition. The control device determines the optimal order in which k-space lines should be scanned, allowing the gradient system to follow a predetermined efficient path that minimizes unnecessary gradient switching and reduces noise while maintaining imaging speed.
Solution Approach 2:
The patent implements dynamics by dynamically adjusting the k-space line ordering and readout direction based on the specific imaging requirements and gradient capabilities. The control device adapts the sequence parameters in real-time to optimize the balance between imaging speed and noise reduction, rather than using a fixed rigid protocol.
2Object-generated harmful factors
If maximum gradient performance is decreased to reduce noise, then noise level is reduced, but echo time increases and measurement quality deteriorates
Solution Approach 1:
The patent applies parameter changes by modifying the k-space traversal parameters including the order in which k-space lines are scanned and the readout direction. These parameter adjustments allow the system to achieve efficient data acquisition without requiring maximum gradient performance, thereby reducing noise while maintaining image quality through optimized parameter selection rather than raw gradient power.
3Loss of time
If gradient switching is accelerated to reduce echo time, then imaging efficiency is improved, but gradient coil heating and vibration increase
Solution Approach 1:
The patent uses preliminary action by pre-determining the optimal k-space line ordering that minimizes the total number of gradient switches required. This predetermined efficient path allows the system to achieve short echo times without unnecessary gradient acceleration, thereby reducing thermal loading on the gradient coils while maintaining rapid imaging capability.
Data Source
AI summary
In a method according to optimize the noise development of a 3D gradient echo sequence in a magnetic resonance system, an optimization of at least one parameter of the gradient echo sequence, from the group including: the excitation pulse (the duration of the excitation pulse); the order of k-space lines to be scanned in k-space; and the readout direction of the k-space lines to be scanned in k-space, is implemented such that the gradients to be switched have optimally minimal slew rates, amplitudes and/or polarity changes.