Magnetic Resonance Preview Image Using Segmented K-Space Sampling
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Solution Overview
Problem
Current magnetic resonance imaging (MRI) techniques face challenges in generating high-quality images quickly, especially when dealing with patients who have metallic orthopedic implants, due to inhomogeneous main magnetic fields, which result in lengthy reconstruction times and inefficient clinical practices.
Innovation Solution
A method involving the acquisition of two parts of magnetic resonance signals using regular and pseudorandomized k-space sampling, allowing for the rapid generation of a preview image to assess measurement quality and subsequent storage for detailed image reconstruction, utilizing linear and iterative reconstruction methods to correct distortions caused by implants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If iterative reconstruction methods are used to correct inhomogeneous main magnetic field, then image quality is improved, but reconstruction time becomes too long for practical use
Solution Approach 1:
The magnetic resonance signal acquisition is divided into two parts: a first part with regular k-space sampling for quick preview image generation, and a second part with pseudorandomized k-space sampling for high-quality iterative reconstruction. This segmentation allows the system to provide immediate feedback while maintaining the option for thorough reconstruction when needed.
Solution Approach 2:
The first part of magnetic resonance signals is acquired and processed to generate a preview image before the second part is fully processed. This preliminary action provides immediate value to the operator while the more time-consuming iterative reconstruction is performed in the background or subsequently.
2Productivity
If regular k-space sampling is used, then preview image generation is fast, but image quality may be compromised
Solution Approach 1:
The acquisition process is segmented into two parts with different sampling strategies. The first part uses regular sampling optimized for speed and preview image generation, while the second part uses pseudorandomized sampling optimized for high-quality iterative reconstruction. Both parts contribute to the final image quality assessment.
Solution Approach 2:
Different sampling patterns are applied to different parts of the data acquisition process. The first part employs regular sampling for its specific purpose of rapid preview generation, while the second part employs pseudorandomized sampling for its specific purpose of high-quality reconstruction, allowing each segment to have optimized local quality properties.
3Measurement precision
If pseudorandomized k-space sampling is used, then iterative reconstruction quality is improved, but acquisition time increases
Solution Approach 1:
The acquisition is divided into two parts where only the second part uses pseudorandomized sampling. This allows the system to benefit from the quality improvements of pseudorandomized sampling while limiting the time penalty to only the portion of acquisition that actually requires it, rather than applying it to the entire acquisition process.
Solution Approach 2:
Pseudorandomized sampling is applied partially to only the second part of the magnetic resonance signals, rather than to the entire acquisition. This partial application provides sufficient data for high-quality iterative reconstruction while minimizing the overall acquisition time compared to applying pseudorandomized sampling throughout.
4Adaptability or versatility
If metallic implants are present in the region under examination, then diagnostic capability is improved, but magnetic field homogeneity deteriorates
Solution Approach 1:
The presence of metallic implants, which cause magnetic field inhomogeneity and are traditionally considered harmful to image quality, is accepted and worked with. The method provides specialized reconstruction techniques that can handle these distortions, converting the previously harmful effect into a manageable characteristic that can be corrected through iterative reconstruction methods.
Solution Approach 2:
The method changes the sampling parameters and reconstruction algorithms to accommodate the presence of metallic implants. By using pseudorandomized sampling and iterative reconstruction techniques, the system adapts to the distorted magnetic field conditions created by implants, maintaining diagnostic capability while managing the field homogeneity issues.
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 quick generation of a preview image for immediate operator assessment, reducing waiting times and improving patient throughput while maintaining high image quality for the final image, even in the presence of metallic implants.
Implementation Method 1
a strong and homogeneous main magnetic field for magnetic resonance imaging
Implementation Method 2
a radio-frequency antenna unit for exciting nuclear spins and for measuring resonance signals caused by the excitation
Data Source
AI summary
Generation of a preview image using magnetic resonance signals is provided. A method for the generation of a preview image using magnetic resonance signals includes acquiring a first part and a second part of magnetic resonance signals. During the acquisition of the first part of the magnetic resonance signals, a first k-space is regularly sampled, while, during the acquisition of the second part of the magnetic resonance signals, a second k-space is sampled in a pseudorandomized manner. The first part of the magnetic resonance signals is used to generate a preview image. The second part or the second part and a subset of the first part of the magnetic resonance signals are stored for the generation of a second image.