MRI RF Pulse Train for T2 Weighting and Fat Suppression
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Solution Overview
Problem
Existing MRI techniques require a long preparation pulse application time when performing both T2 weighting and suppression of specific signals, as they necessitate sequential application of DE and saturation pulses.
Innovation Solution
An RF pulse applying method that uses a pulse train of DE pulses, where specific RF pulses provide 360° rotation to the longitudinal magnetization of the component to be measured while avoiding rotation for the component to be suppressed, allowing for simultaneous T2 weighting and signal suppression within a shorter preparation time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If DE pulse and saturation pulse are applied in order to achieve both T2 weighting and signal suppression, then both functions are achieved, but preparation pulse application time becomes long
Solution Approach 1:
The patent merges the DE pulse and saturation pulse into a single integrated pulse sequence. By designing a composite pulse that combines the T2 weighting function of the DE pulse with the signal suppression function of the saturation pulse, the system achieves both objectives simultaneously without requiring sequential application, thereby reducing preparation time while maintaining suppression effectiveness.
Solution Approach 2:
The patent creates a universal preparation pulse sequence that performs multiple functions: T2 weighting and signal suppression from specific components. This multi-functional pulse design eliminates the need for separate dedicated pulses for each function, allowing the system to achieve both T2 weighting and component-specific suppression within a single preparation phase.
2Reliability
If DE pulse is applied for T2 weighting, then T2 weighting is achieved, but additional saturation pulse time is required for signal suppression
Solution Approach 1:
The patent combines the T2 weighting mechanism and signal suppression mechanism into a single integrated pulse sequence. The composite pulse maintains the T2 weighting accuracy of the original DE pulse while incorporating signal suppression capabilities, thereby achieving both objectives without requiring additional separate pulses that would reduce imaging speed.
3Reliability
If saturation pulse is applied for signal suppression, then suppression effectiveness is improved, but preparation time increases
Solution Approach 1:
The patent merges the saturation pulse function into the DE pulse sequence, creating a composite pulse that performs both T2 weighting and signal suppression. This integration eliminates the need for a separate saturation pulse application phase, thereby maintaining suppression effectiveness while reducing the total preparation time.
Solution Approach 2:
The patent incorporates the signal suppression function into the initial DE pulse sequence design, performing suppression action simultaneously with T2 weighting rather than as a subsequent separate step. This preliminary integration of suppression functionality within the main pulse sequence reduces overall preparation time while maintaining effectiveness.
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 method enables T2 weighting and signal suppression from specific components in a shorter preparation pulse application time, maintaining the effectiveness of T2 weighting for the component of interest while suppressing unwanted signals without increasing overall preparation time.
Implementation Method 1
an RF pulse as a part of a pulse train that gives rotation of an integral multiple of 360° to longitudinal magnetization of a component to be measured is set as an RF pulse which does not give rotation to longitudinal magnetization of a component to be suppressed
Data Source
AI summary
The present invention is directed to perform T2 weighting and suppression of a signal from a specific component in short preparation pulse application time. A first 90° pulse in DE pulses is a pulse which is selectively valid for water and makes the longitudinal magnetization of water turn by 90° about the x axis as a rotation axis. A 180° pulse is a pulse which is valid for water and fat and makes the longitudinal magnetization of water and fat turn by 180° about the x axis as a rotation axis. A second 90° pulse is a pulse which is valid for water and fat and makes the longitudinal magnetization of water and fat turn by 90° about the x axis as a rotation axis. By the DE pulses, the longitudinal magnetization of water is rotated by 360°, and the effect of T2 weighting is obtained in a manner similar to the conventional DE pulses. The longitudinal magnetization of fat is rotated by 270° and does not return to the original longitudinal magnetization so that the effect of suppressing a signal is obtained. Since only application time of the DE pulses is sufficient, time required to apply a preparation pulse does not increase.