MRI Image Reconstruction With Extended Motion Correction Windows
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing MRI technologies struggle to completely remove body motion artifacts due to timing errors in body motion detection and the persistence of motion-induced echo signal instability, which conventional methods fail to adequately address.
Innovation Solution
The MRI apparatus extends the detected body motion period by defining a second period that includes the first detected period, allowing for the removal or correction of data collected during this extended period to suppress motion-induced artifacts, using a combination of navigator data and camera video for accurate body motion detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If body motion detection means (camera or navigator echo) is used to detect body motion, then body motion can be detected, but timing errors occur between detection timing and actual motion occurrence, and fine motions remain undetected
Solution Approach 1:
The patent applies preliminary action by defining a second period that extends before and after the detected first period of body motion. This anticipatory approach accounts for timing errors in detection by proactively including potential motion periods in the correction range, ensuring that even if detection timing is slightly off, the artifact removal remains effective.
Solution Approach 2:
The patent implements beforehand cushioning by creating a buffer zone (second period) around the detected motion period. This cushioning approach compensates for detection inaccuracies and ensures that data from potentially affected periods are included in the correction, thereby maintaining high reliability in artifact removal despite timing errors.
2Object-affected harmful factors
If data collected during detected body motion period is processed, then body motion artifact suppression is performed, but echo signal steady state collapses cause artifacts to persist
Solution Approach 1:
The patent applies preliminary action by extending the correction period to include time before and after the detected motion period. This ensures that the echo signal steady state collapse, which occurs after motion stops, is also accounted for in the artifact removal process, preventing persistent artifacts.
Solution Approach 2:
The patent implements beforehand cushioning by creating a temporal buffer that extends beyond the detected motion period. This cushioning ensures that the steady state collapse period is included in the correction range, thereby maintaining image reconstruction accuracy and preventing residual artifacts.
3Ease of operation
If conventional body motion processing is used, then detection and correction control is performed, but fine motions inside the examination target that are not captured by camera or navigator echo remain
Solution Approach 1:
The patent applies preliminary action by extending the correction period proactively to cover potential fine motion periods that may not be captured by external detection means. This anticipatory approach ensures that even undetected fine motions are accounted for in the artifact removal process.
Solution Approach 2:
The patent implements beforehand cushioning by creating a buffer zone around the detected motion period. This cushioning approach compensates for the limitations of external detection means (camera/navigator echo) in capturing fine internal motions, ensuring comprehensive artifact removal without requiring direct detection of all motion types.
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 effectively reduces body motion artifacts by accounting for detection timing errors and echo signal stabilization, resulting in high-accuracy image reconstruction with improved suppression of motion-induced image distortions.
Implementation Method 1
an RF transmitting unit that applies a high-frequency magnetic field pulse to an examination target placed in a static magnetic field space
Implementation Method 2
a gradient magnetic field generation unit that generates a gradient magnetic field pulse for applying a magnetic field gradient to a static magnetic field
Implementation Method 3
an RF receiving unit that receives a nuclear magnetic resonance signal emitted by the examination target
Data Source
AI summary
Provided is a technique of improving accuracy of image reconstruction accompanied by body motion correction processing.In a case in which a period during which a body motion occurs is defined as a first period based on a result of detecting a body motion of an examination target disposed in a static magnetic field space, a second period that includes the first period and that is longer than the first period is specified. In measurement data of the examination target collected by magnetic resonance imaging, data collected in the second period is removed or corrected to generate an image of the examination target. As the second period, a detection timing error can be compensated for by extending a start end side of the first period, and data collected at a time at which a signal is unstable due to the body motion can be removed by extending a terminal end side.