Multi-Echo K-Space Sampling for Motion-Robust MR Imaging
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Solution Overview
Problem
Current MR imaging techniques, such as Turbo Spin Echo sequences, are highly sensitive to motion, leading to ghosting artifacts that compromise diagnostic image quality due to regular k-space sampling patterns.
Innovation Solution
The method involves sampling the same k-space lines multiple times with varying sequential orders and densities, particularly in the peripheral regions, and combining this with Dixon imaging to optimize the acquisition and reconstruction of MR images, thereby reducing motion-induced artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If regular k-space sampling patterns are used in Turbo Spin Echo sequences, then imaging speed is improved, but motion sensitivity increases leading to ghosting artifacts
Solution Approach 1:
The patent applies dynamics by making the k-space sampling pattern variable rather than fixed. The sequential order of sampling k-space lines is changed between different acquisitions, creating a dynamic sampling scheme that adapts to reduce motion artifacts while maintaining imaging speed. This is achieved by randomizing or varying the echo train ordering across multiple shots.
Solution Approach 2:
The patent uses preliminary action by acquiring multiple k-space lines in advance with different sampling orders before image reconstruction. Multiple acquisitions with varied sampling patterns are performed beforehand, and then combined through averaging to produce the final image, thereby preemptively reducing motion artifacts.
2Area of stationary object
If multiple shots are used to sample k-space completely, then imaging coverage is improved, but acquisition time increases
Solution Approach 1:
The patent applies partial action by sampling certain k-space lines multiple times with different orders while using fewer total shots compared to conventional complete sampling. This selective repeated sampling of critical k-space regions achieves adequate image quality with reduced acquisition time.
Solution Approach 2:
The patent uses periodic action by repeating the sampling of specific k-space lines across multiple acquisitions with different sequential orders. This periodic resampling with varied ordering allows for efficient k-space coverage that reduces both acquisition time and motion artifacts.
3Reliability
If k-space lines are sampled repeatedly with different sequential orders, then motion artifact reduction is improved, but data processing complexity increases
Solution Approach 1:
The patent applies merging by combining multiple k-space datasets acquired with different sampling orders into a single final image through averaging. This consolidation of multiple acquisitions with varied sequences simplifies the overall process while effectively reducing motion artifacts through the combining operation.
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 results in more robust and accurate MR imaging by averaging out motion artifacts, improving signal-to-noise ratio, and reducing ghosting, leading to higher diagnostic image quality.
Implementation Method 1
at least one main magnet coil (2) configured for generating a uniform static magnetic field within an examination volume
Implementation Method 2
a number of gradient coils (4, 5, 6) for generating switched magnetic field gradients in different spatial directions within the examination volume
Implementation Method 3
at least one RF coil (9) for generating RF pulses within the examination volume and/or for receiving MR signals from an object positioned in the examination volume
Data Source
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AI summary
The invention relates to a method of MR imaging of at least an object (10) placed in an examination volume of a MR device (1). It is an object of the invention to enable fast MR imaging using a multi-echo imaging technique which is robust with respect to motion. The method of the invention comprises the steps of: - generating echo signals by subjecting the object (10) to an imaging sequence, - acquiring the echo signals, each echo signal being attributed to a k-space line, wherein a number of k-space lines, which are adjacently arranged in a part of k-space, are repeatedly sampled, with said number of k-space lines being sampled in a different sequential order per repetition, and - reconstructing a MR image from the acquired echo signals. Moreover, the invention relates to a MR device for carrying out this method as well as to a computer program to be run on a MR device.