MRI Motion Correction via K-Space Cross-Correlation
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Solution Overview
Problem
Current methods for motion correction in magnetic resonance imaging (MRI) systems often increase scan time or require a priori knowledge of motion type, leading to inefficiencies and limitations in reducing motion artifacts.
Innovation Solution
A method involving the cross-correlation of two sets of k-space data to calculate and correct for motion, allowing for retrospective correction of k-space data without the need for additional navigator echoes or prior knowledge of motion type.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional motion correction methods using navigator echoes are used, then motion artifacts are reduced, but scan time increases substantially
Solution Approach 1:
The patent extracts and removes the need for separate navigator echoes by using only the actual imaging k-space data for motion correction. The cross-correlation is performed directly on the imaging data lines, eliminating the additional navigator echo acquisitions that traditionally were required for motion tracking, thus reducing scan time while maintaining motion correction capability
Solution Approach 2:
The patent makes the imaging k-space data serve dual purposes: both for image reconstruction and for motion correction through cross-correlation. The same data lines used for imaging are also used to calculate motion estimates, eliminating the need for separate dedicated motion tracking data and achieving multi-functionality with existing resources
2Measurement precision
If navigator echoes are used for motion correction, then motion information is obtained, but device complexity and data processing requirements increase
Solution Approach 1:
The patent removes the separate navigator echo acquisition system and complexity by extracting motion information directly from the imaging data itself. The cross-correlation operation is performed on the imaging k-space lines, eliminating the need for separate motion tracking hardware and processing pipelines
Solution Approach 2:
The imaging data serves itself by providing both the image information and the motion correction information. The k-space lines automatically contain the motion signatures that can be extracted through cross-correlation, making the system self-sufficient without requiring external or separate motion tracking mechanisms
3Manufacturing precision
If multiple receiver coils are used for parallel MRI, then spatial resolution and temporal resolution are improved, but motion artifacts increase
Solution Approach 1:
The patent segments the k-space data by receiver coil and performs cross-correlation on corresponding lines from different coils. This segmented approach allows motion correction to be applied independently to each coil's data while maintaining the benefits of parallel imaging, thereby reducing motion artifacts without sacrificing the resolution advantages of multiple coils
Solution Approach 2:
The patent implements a feedback mechanism where motion estimates derived from cross-correlation of k-space lines are used to correct the imaging data. The motion correction factor calculated from the cross-correlation maximum is applied back to the original imaging data, creating a closed-loop system that continuously compensates for motion effects while preserving the high resolution benefits of parallel MRI
Data Source
AI summary
A method, a system, and a computer-readable medium are provided which perform motion correction of image data. A first set of data and a second set of data of k-space data of an object to be imaged are received. The first set of data and the second set of data include a plurality of phase encoded lines that encompass the object to be imaged. The first set of data correlates with the second set of data. A cross-correlation is calculated by multiplying the first set of data and the second set of data in k-space. A value of the motion of the object to be imaged that occurred between acquisition of the first set of data and acquisition of the second set of data is calculated using the cross-correlation. The second set of data is corrected using the calculated value to remove the motion. The correction process is repeated until the k-space data is completely processed.