MRI k-space trajectory modulation for artifact reduction
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Solution Overview
Problem
Existing 3D radial imaging techniques suffer from artifacts such as streaking in central slices during axial head imaging due to the regular planar-like spacing of spoke end-points in the k-space trajectory, which affects image quality.
Innovation Solution
Modulating the polar angle of the k-space trajectory in a sinusoidal manner during data acquisition to disperse the bright polar point spread function region, thereby eliminating streak artifacts by disturbing the regular spacing of radial spokes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a regular planar-like spacing of spoke end-points is used in the k-space trajectory, then the imaging sequence is simple and fast, but streaking artifacts appear in central slices
Solution Approach 1:
The patent applies asymmetry by modulating the polar angle of the k-space trajectory to break the symmetric, regular planar-like spacing of spoke end-points. This modulation creates an asymmetric distribution that disperses the bright polar point spread function region, thereby eliminating the streaking artifacts while maintaining imaging efficiency.
Solution Approach 2:
The patent implements dynamics by dynamically modulating the polar angle of the k-space trajectory during data acquisition. Instead of using a static, fixed trajectory, the system dynamically adjusts the trajectory parameters to achieve optimal artifact reduction while maintaining productivity.
2Manufacturing precision
If the k-space trajectory is modified to eliminate artifacts, then image quality improves, but the complexity of the imaging sequence increases
Solution Approach 1:
The patent applies parameter changes by modulating the polar angle parameter of the k-space trajectory. This controlled change in trajectory parameters improves image quality by eliminating streaking artifacts while maintaining relative simplicity through a systematic parameter modulation approach rather than complex structural changes.
3Loss of time
If axial images are acquired directly with modified trajectory, then reformatting time is saved, but the trajectory modulation adds acquisition complexity
Solution Approach 1:
The patent applies preliminary action by pre-planning and pre-defining the polar angle modulation pattern before data acquisition. The trajectory modulation is designed in advance to directly produce artifact-free axial images, eliminating the need for subsequent reformatting operations and saving time despite the added acquisition complexity.
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 results in artifact-free images by modifying the k-space trajectory, improving image quality and reducing scan time by providing high-quality axial images directly without the need for reformatting from sagittal or coronal images.
Implementation Method 1
Magnetic Resonance Imaging (MRI) is a widely accepted and commercially available technique for obtaining digitized visual images representing the internal structure of objects having substantial populations of atomic nuclei that are susceptible to nuclear magnetic resonance (NMR)
Implementation Method 2
Modulating the polar angle of the k-space trajectory in a sinusoidal manner during data acquisition to disperse the bright polar point spread function region, thereby eliminating streak artifacts by disturbing the regular spacing of radial spokes
Data Source
AI summary
A method of magnetic resonance imaging includes executing an imaging sequence, in response to the imaging sequence, acquiring magnetic resonance data, entering the acquired magnetic resonance data in k-space in a memory along a predetermined k-space trajectory, and modifying the k-space trajectory during acquisition of the magnetic resonance data.