MRI STIR Fat Suppression via Gradient Pulse Alignment
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Solution Overview
Problem
Conventional MRI systems using Short TI Inversion Recovery (STIR) methods face challenges in achieving uniform fat suppression due to chemical shifts between inversion and flip pulses, leading to image quality degradation and fat suppression defects.
Innovation Solution
The MRI apparatus and method determine imaging parameters to align the slice selecting gradient magnetic field intensities for inversion and flip pulses, adjusting the pulse parameters and gradient magnetic field intensities to minimize chemical shift differences, thereby synchronizing the excitation positions of fat components by both pulses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional STIR methods are used with fixed pulse parameters, then the imaging process is simple, but fat suppression uniformity deteriorates due to chemical shifts between inversion and flip pulses
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the slice selecting gradient magnetic field intensity for the inversion pulse based on the flip pulse parameters. Specifically, the gradient intensity is modified to compensate for chemical shift effects, ensuring that fat components are excited at the same position by both pulses. This parameter adjustment resolves the contradiction by maintaining fat suppression uniformity while managing the complexity through automated determination processes.
2Manufacturing precision
If the slice selecting gradient magnetic field intensity is not adjusted, then the imaging process is fast, but excitation positions of fat components differ between inversion and flip pulses causing image quality degradation
Solution Approach 1:
The patent implements preliminary action by determining the optimal slice selecting gradient magnetic field intensity for the inversion pulse before actual image acquisition. The system calculates the appropriate gradient intensity based on flip pulse parameters and chemical shift characteristics in advance, ensuring that excitation positions are aligned without adding significant time to the main imaging process. This preliminary determination resolves the contradiction by achieving precise excitation position alignment while minimizing time loss.
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 improves fat suppression uniformity and reduces image quality issues by aligning the excitation positions of fat components, enhancing the stability and accuracy of MR images generated by the STIR method.
Implementation Method 1
it is also known that a chemical shift occurs because the magnetic resonance frequency of water is different from the magnetic resonance frequency of fat
Implementation Method 2
Short TI Inversion Recovery (STIR) methods are known as methods implemented by Magnetic Resonance Imaging (hereinafter, 'MRI') apparatuses to obtain fat-suppressed images
Data Source
AI summary
A magnetic resonance imaging apparatus according to an embodiment includes processing circuitry configured, on a basis of one or both of (A) a parameter related to applying one of inversion and flip pulses and (B) an intensity of a slice selecting gradient magnetic field applied together with the one of the pulses in relation to selecting a slice to which the one of the pulses is applied, to determine one or both of (A) a parameter related to applying the other of the inversion and (B) flip pulses; and an intensity of the slice selecting gradient magnetic field applied together with the other of the pulses in relation to selecting a slice to which the other of the pulses is applied.