MR Control Sequence Adjustment for Fat Saturation
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Solution Overview
Problem
Conventional methods for adjusting magnetic resonance (MR) control sequences in magnetic resonance devices lack precision in accounting for the differences in substances like fat and water, leading to suboptimal image quality due to a fixed chemical shift-based adjustment, which does not adequately consider the spatial distribution and properties of various substances within the examination area.
Innovation Solution
The method involves determining independent reference values for different substances and high-frequency pulses, allowing for selective excitation and adjustment of the MR control sequence based on the specific properties and spatial distribution of substances, such as water and fat, to achieve precise resonant excitation and improved image data quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fixed chemical shift-based adjustment is used for MR control sequences, then the adjustment process is simple, but the precision of accounting for substance differences (fat and water) is insufficient
Solution Approach 1:
The patent segments the adjustment process into separate reference value determinations for different substances (fat and water). Instead of using a single fixed chemical shift value, the system determines independent reference values for each substance group, allowing precise accounting for their different properties and spatial distributions while maintaining a systematic and manageable adjustment process.
Solution Approach 2:
The patent changes the adjustment parameter from a fixed chemical shift value to variable reference values that are determined based on the actual spatial distribution and properties of substances in the examination area. This allows the system to adapt to different examination scenarios and substance distributions, improving precision without requiring complete process redesign.
2Manufacturing precision
If independent reference values for different substances are determined, then the image data quality and homogeneity improve, but the adjustment process becomes more complex
Solution Approach 1:
The system performs self-adjustment by automatically determining reference values for different substances based on their spatial distributions. The control unit executes the adjustment process autonomously using the determined reference values, reducing the need for manual intervention and complex operator procedures while achieving improved image homogeneity.
Solution Approach 2:
The patent modifies the control parameters of the MR sequence by assigning substance-specific reference values to different radiofrequency pulses. This parameter adaptation allows the system to account for spatial distribution differences and property variations of substances, achieving homogeneous image data through systematic parameter optimization rather than procedural complexity.
3Measurement precision
If spatial distribution and properties of substances are considered in adjustment, then fat saturation and contrast modulation are enhanced, but the measurement and detection difficulty increases
Solution Approach 1:
The patent segments the substance groups into distinct categories (e.g., fat and water) and determines reference values for each group separately. This segmentation allows the system to focus on characteristic properties of each substance group rather than attempting to measure and differentiate all individual substance properties, reducing measurement complexity while improving fat saturation precision.
Solution Approach 2:
The system uses parameter changes in the reference values to account for spatial distribution and property differences of substances. By adjusting the reference values based on substance characteristics and their spatial distributions, the system enhances fat saturation and contrast modulation without requiring direct measurement of all substance properties, thus reducing detection difficulty.
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 enables more precise adjustment of the MR control sequence, resulting in higher quality and homogeneity of image data by accurately accounting for the properties and spatial distribution of substances, particularly enhancing fat saturation and contrast modulation.
Implementation Method 1
the body to be examined, especially a patient, is typically exposed to a relatively high main magnetic field, for example, 1.5, 3, or 7 Tesla, using a main magnet
Implementation Method 2
High-frequency radio-frequency pulses, such as excitation pulses, are then emitted via a radio-frequency antenna unit using suitable antenna devices. This causes the resonantly excited nuclear spins of certain atoms to be tilted by these radio-frequency pulses by a defined flip angle relative to the magnetic field lines of the main magnetic field
Implementation Method 3
Fat saturation can be achieved spectrally, exploiting the chemical shift between nuclear spins in fat and nuclear spins in water: Nuclear spins in fat and nuclear spins in water exhibit a different resonance frequency, i.e., Larmor frequency, relative to the strength of the main magnetic field
Implementation Method 4
Additionally, gradient pulses are generated using a gradient coil unit. These gradient pulses are used for spatial encoding
Data Source
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AI summary
The invention relates to a method for adjusting an MR control sequence comprising a first radio frequency pulse and a second radio frequency pulse for a magnetic resonance examination of an area of an object under investigation by means of the MR control sequence according to the following method steps: - Determining a first reference value for the first radio frequency pulse for the resonant excitation of a first substance, - Determining a second reference value for the second radio frequency pulse for the resonant excitation of a second substance, wherein the determination of the first reference value comprises a selective excitation of the first substance and/or the determination of the second reference value comprises a selective excitation of the second substance, - Adjusting the MR control sequence by assigning the first reference value to the first radio frequency pulse and assigning the second reference value to the second radio frequency pulse.