MRI Motion Correction via Multi-Sensor Signal Correlation
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Solution Overview
Problem
Existing MR imaging techniques often incorrectly detect motion, leading to inferior image quality due to wrongly detected respiratory movements, particularly when using camera-based motion correction methods that rely on markers or face monitoring, as these methods fail to differentiate between actual and wrongly detected motion.
Innovation Solution
A method that detects two independent motion signals during MR imaging, correlating them to separate actual from wrongly detected motion, allowing for accurate motion compensation by using sensors and pilot tone signals to distinguish between real and artifact-induced movements, ensuring only actual motion is corrected in MR images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Difficulty of detecting and measuring
If camera-based motion correction with markers is used, then motion detection capability is improved, but measurement precision deteriorates due to wrongly detected motion
Solution Approach 1:
The patent segments the motion detection task into multiple independent motion signals from different sensors (camera, pneumatic cuff, pilot tone) rather than relying on a single marker-based camera system. This segmentation allows the system to differentiate between actual head motion and respiratory-induced nose motion by comparing multiple independent measurements.
Solution Approach 2:
The patent introduces intermediate motion signals from auxiliary sensors (pneumatic cuff measuring chest expansion, pilot tone measuring head position) that serve as mediators to verify and distinguish the authenticity of motion detected by the camera. These intermediaries help identify whether detected motion is genuine head movement or artifact from respiration.
2Device complexity
If motion correction is applied based on single motion signal, then motion compensation is simplified, but image quality deteriorates due to wrong motion detection
Solution Approach 1:
The patent segments the motion correction process into multiple independent correction calculations using different motion signals, then combines them through correlation analysis. Rather than applying a single correction, the system performs separate corrections based on camera data, pneumatic cuff data, and pilot tone data, then identifies the correct correction through signal correlation.
Solution Approach 2:
The patent implements feedback by continuously monitoring multiple motion signals and using their correlation to verify the authenticity of detected motion. The system feedbacks on whether the detected motion is genuine by comparing it with independent measurements from other sensors, adjusting the correction applied accordingly.
3Difficulty of detecting and measuring
If marker is attached to nose for motion tracking, then motion detection sensitivity is improved, but harmful factors increase due to patient irritation and false motion detection
Solution Approach 1:
The patent uses the pneumatic cuff as an intermediary to measure respiratory motion indirectly through chest expansion, and the pilot tone as an intermediary to measure head position through electromagnetic interaction. These intermediaries provide verification data to distinguish whether nose marker motion is due to actual head movement or respiratory movement, reducing false detection caused by patient irritation.
Data Source
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AI summary
The invention relates to a method for correcting a wrongly detected motion of an object under examination during an MR imaging procedure at which MR signals from a first part of the object under examination are detected in order to generate MR images of the first part, the method comprising: - detecting a first motion signal of the objet under examination during MR signal detection, wherein the first motion signal is independent of a position from which the MR signals are originating in the object under examination, - detecting a second motion signal of the objet under examination during MR signal detection, wherein the second motion signal is independent of a position from which the MR signals are originating in the object under examination, - correlating the first motion signal with the second motion signal in order to separate an actual motion of the first part of the object under examination during MR signal detection from the wrongly detected motion in which the first part of the object under examination is not moving but a second part different from the first part of the object under examination is moving, wherein a presence of the actual and wrongly detected motion in the two motion signals is different, - carrying out a motion compensation on the generated MR images in which substantially only the actual motion and not the wrongly detected motion of the object under examination is corrected in the detected MR signals.