MRI Motion Correction via K-Space Segmentation
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Solution Overview
Problem
Current magnetic resonance imaging (MRI) techniques for motion correction, such as the navigator echo method and three-dimensional registration, either reduce data acquisition rates or are limited to slow motion corrections, making them inefficient for fast motion correction and image quality.
Innovation Solution
A magnetic resonance imaging apparatus that performs stack-of-stars data acquisition, divides time-series k-space data into groups, calculates motion feature amounts based on k-space central portion data, and corrects k-space data using these features to generate corrected k-space data for improved image reconstruction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If navigator echo method is used for motion correction, then motion correction capability is improved, but data acquisition rate deteriorates
Solution Approach 1:
The patent extracts only the central portion (low-frequency components) from the acquired k-space data to create a reduced data set for motion estimation. This extracted subset is sufficient for calculating motion feature amounts while preserving the main imaging data for high-quality reconstruction, thus enabling motion correction without sacrificing data acquisition rate.
Solution Approach 2:
The patent segments the k-space data into different frequency components, separating the central low-frequency portion used for motion estimation from the peripheral high-frequency portion used for detailed image reconstruction. This segmentation allows independent processing of motion correction and image formation, resolving the contradiction between correction accuracy and acquisition efficiency.
2Measurement precision
If three-dimensional registration is performed on reconstructed images, then image quality for registration is improved, but data acquisition time deteriorates
Solution Approach 1:
The patent performs motion estimation using only the central k-space data before complete image reconstruction is finished. By conducting motion correction in advance using the available central portion data, the system eliminates the need for additional acquisition time that would be required if motion correction waited until after full reconstruction.
Solution Approach 2:
The patent uses only a partial data set (central k-space portion) for motion estimation rather than requiring the complete data set for high-quality reconstruction. This partial action provides sufficient motion information for correction while avoiding the time penalty of acquiring and processing all data before correction can begin.
3Measurement precision
If complete k-space data is used for motion estimation, then motion correction accuracy is improved, but data acquisition rate deteriorates
Solution Approach 1:
The patent extracts only the necessary central portion of k-space data for motion estimation, removing the redundant peripheral data from the motion analysis process. This extraction maintains sufficient motion estimation accuracy while dramatically reducing the data volume that would otherwise slow down acquisition and processing.
Data Source
AI summary
An MRI apparatus 1 includes sequence control circuitry 29 and processing circuitry 51. The sequence control circuitry 29 performs stack-of-stars data acquisition on an imaging region of a subject to acquire time-series k-space data. The processing circuitry 51 divides time-series k-space data into groups relating to a time direction, and calculates for each of the groups a motion feature amount of the imaging region based on k-space data of a k-space central portion. The processing circuitry 51 corrects for each of the groups the k-space data based on the motion feature amount and generates the corrected k-space data. The processing circuitry 51 reconstructs an MR image relating to the imaging region based on the corrected k-space data relating to the groups.