Eddy Current Phase Error Correction in MRI Multi-Echo Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing magnetic resonance imaging (MRI) technologies face challenges in accurately correcting eddy current-induced phase errors in multi-echo images, leading to inconsistencies in water-fat separation algorithms, which are complex, time-consuming, or prone to errors.
Innovation Solution
A method and apparatus that estimate and remove eddy current-induced phase errors by calculating coefficients for first- and zero-order terms using specific image processing steps, allowing for efficient correction without additional data acquisition or multiple iterations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If reference acquisition is adopted to remove the phase error caused by the eddy current, then the phase error can be removed, but additional data acquisition is required and the time is prolonged
Solution Approach 1:
The patent extracts the eddy current phase error as a separate correctable component from the MRI signal. By modeling the phase error as θ=αx+β and using phase difference calculations between adjacent echoes, the method isolates and removes the eddy current effect without requiring additional reference acquisitions, thus maintaining accuracy while reducing time loss
Solution Approach 2:
The patent uses the acquired multi-echo data itself to calculate and remove the eddy current phase error. Through phase difference operations between adjacent echoes and solving the linear model θ=αx+β, the system self-corrects the phase error using its own data, eliminating the need for external reference acquisitions and reducing total acquisition time
2Reliability
If one-to-many echo images are acquired with opposite readout gradient polarities to remove eddy current influence, then the eddy current influence can be removed, but the scanning time is doubled
Solution Approach 1:
The patent extracts the eddy current phase error component from the acquired multi-echo data by calculating phase differences between adjacent echoes. This allows the system to isolate and correct the eddy current effect using only the originally acquired data, eliminating the need for additional opposite-polarity acquisitions and maintaining scanning efficiency
Solution Approach 2:
The system uses its own acquired multi-echo data to self-correct the eddy current phase errors through phase difference calculations and linear model fitting. This self-service approach removes the need for separate correction acquisitions, maintaining both accuracy and productivity
3Reliability
If the water, fat, and eddy current are solved simultaneously when the model is fitted, then the eddy current can be corrected, but the algorithm is complicated and may converge to local minimum
Solution Approach 1:
The patent segments the correction process into distinct steps: first calculating phase differences between adjacent echoes, then fitting the linear model θ=αx+β to extract eddy current coefficients, and finally applying the correction. This segmentation simplifies the algorithm by avoiding simultaneous solving of multiple parameters, reducing computational complexity while maintaining correction accuracy
Solution Approach 2:
The patent performs preliminary phase difference calculations and eddy current coefficient estimation before the main water-fat separation fitting. By pre-calculating the eddy current phase correction terms, the algorithm avoids the complexity of simultaneous multi-parameter optimization and reduces the risk of converging to local minima
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 accurate correction of eddy current-induced phase errors, ensuring the reliability of water-fat separation algorithms by simplifying the process and reducing computational complexity.
Implementation Method 1
the bipolar readout method is always affected by the eddy current of the system
Data Source
AI summary
An eddy-current correction method and apparatus, a mobile terminal and a readable storage medium are provided. The method includes: step S1: reading gradient-recalled echo sequence by means of bipolarity, so as to acquire a multi-echo image; step S2: estimating a first-order term coefficient of an extra phase term introduced by an eddy-current in the acquired multi-echo image; step S3: removing the estimated first-order term coefficient, and estimating a zero-order term coefficient of the extra phase term introduced by the eddy-current in the collected multi-echo image; step S4: removing, according to the estimated first-order term coefficient and the zero-order term coefficient, an error of the extra phase term introduced by the eddy-current. The eddy-current correction method removes the phase error caused by the eddy-current in the acquired image, thereby ensuring the correctness of the subsequent water-fat separation algorithm result.