Multi-shot MRI Motion Correction via Folded Image Similarity
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Solution Overview
Problem
Multi-shot magnetic resonance imaging (MRI) techniques face challenges with motion artifacts due to inter-shot motion, leading to reduced image quality and longer acquisition times, with existing methods being time-consuming and computationally costly.
Innovation Solution
A magnetic resonance imaging system that detects and corrects inter-shot motion by generating folded images from partially acquired MR raw data, using similarity measurements to identify pixel magnitude discrepancies between successive shots, allowing for accurate motion detection and reconstruction of artifact-free images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional navigator based methods are used to detect inter-shot motion, then motion detection capability is provided, but acquisition time increases and mis-registration issues occur
Solution Approach 1:
The patent extracts only the necessary portion of data (partially acquired data) to generate folded images for motion detection, rather than requiring fully acquired data. This extraction approach enables motion detection while reducing acquisition time by avoiding unnecessary data collection steps.
Solution Approach 2:
The patent performs motion detection using folded images generated from partially acquired data before the complete imaging sequence is finished. This preliminary motion detection allows for real-time motion correction without waiting for full data acquisition, thereby reducing total acquisition time.
2Manufacturing precision
If multi-shot methods are used to obtain high-spatial-resolution images, then image resolution is improved, but acquisition time increases
Solution Approach 1:
The patent uses partially acquired data to generate folded images for motion detection purposes, rather than requiring complete data acquisition. This partial action approach enables motion correction functionality without the full time cost of complete multi-shot acquisition, thus reducing overall acquisition time while maintaining high spatial resolution.
3Measurement precision
If parallel imaging method is used for motion correction, then motion correction capability is provided, but computational cost increases
Solution Approach 1:
The patent implements self-navigated motion correction where the folded images generated from the imaging data itself are used to detect and correct motion. This self-service approach eliminates the need for separate navigator echoes or external motion tracking systems, reducing computational overhead while maintaining motion correction capability.
4Measurement precision
If non-Cartesian trajectory is used for self-navigated imaging, then motion detection is enabled, but imaging stability decreases
Solution Approach 1:
The patent uses Cartesian trajectories for both the navigator and imaging data acquisition, ensuring homogeneous and consistent sampling patterns. This homogeneity improves imaging stability and facilitates reliable motion detection through folded image comparison, avoiding the instability associated with non-Cartesian methods.
Data Source
AI summary
The present invention provides a magnetic resonance imaging system for imaging a subject by a multi-shot imaging. The magnetic resonance imaging system comprises an acquiring unit for acquiring MR raw data corresponding to a plurality of shots; an imaging unit for generating a plurality of folded images from the MR raw data, wherein each of the plurality of folded images is generated from a subset of the MR raw data; a deriving unit for deriving magnitude of each pixel of each folded image; a detecting unit for detecting a motion of the subject during the multi-shot imaging based on similarity measurements of any two folded images of the plurality of folded images, wherein the detecting unit further comprises a first deriving unit configured to derive the measured similarities; and a reconstructing unit for reconstructing a MR image of the subject based on MR raw data obtained according to a detection result of the detecting unit. Since the partially acquired MR raw data is used for motion detection directly, it would be more rapid and stable.