MRI Ringing Correction Using Continuous Pixel Shift Mapping
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Solution Overview
Problem
Magnetic Resonance Imaging (MRI) images often contain ringing artifacts near signal intensity boundaries, leading to blurred images when conventional correction methods are applied.
Innovation Solution
An image processing apparatus that estimates local amplitudes of ringing artifacts and performs a ringing correction by determining shift amounts for each pixel to be approximately continuous with adjacent pixels, using sub-voxel shifts to reduce artifacts while maintaining image clarity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional correction methods are applied to reduce ringing artifacts, then the ringing artifacts are reduced, but the image becomes blurred
Solution Approach 1:
The patent applies different shift amounts to different pixels based on their local ringing artifact amplitudes. By estimating the local amplitude of ringing artifacts for each pixel and determining shift amounts specifically for regions with high artifact levels, the correction is applied locally rather than globally, thus reducing artifacts in affected areas while preserving clarity in unaffected areas.
Solution Approach 2:
The patent dynamically determines shift amounts for each pixel based on local image characteristics and ringing artifact amplitudes, rather than applying a fixed or uniform correction. The shift amount varies from pixel to pixel, allowing the correction to adapt to local image features and minimize blurring while reducing artifacts.
2Object-affected harmful factors
If shift amounts are determined independently for each pixel, then ringing artifacts are reduced at that pixel, but discontinuity between adjacent pixels causes additional artifacts
Solution Approach 1:
The patent uses the estimated local amplitude of ringing artifacts as feedback to determine appropriate shift amounts. By considering both the local artifact amplitude and the shift amounts of adjacent pixels, the system feedback-adjusts the shift amount to achieve both artifact reduction and continuity, preventing new artifacts from arising at pixel boundaries.
Solution Approach 2:
The patent changes the parameter of shift amount continuously across adjacent pixels rather than applying discrete, independent values. By ensuring that shift amounts vary smoothly from one pixel to the next, the patent maintains image stability and prevents discontinuities that would create additional artifacts.
Data Source
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AI summary
An image processing apparatus (100) according to an embodiment includes a correcting unit (152). The correcting unit (152) determines, with respect to each of the pixels included in a magnetic resonance image, a shift amount from the position of the pixel to a position where ringing artifacts will be reduced and performs a ringing correction to correct the ringing artifacts occurring in the magnetic resonance image on the basis of the determined shift amounts. The correcting unit (152) estimates, with respect to each of the pixels, a local amplitude of ringing artifacts, and performs the ringing correction on the magnetic resonance image while determining the shift amount of each of the pixels so as to be approximately continuous with the shift amounts of adjacently positioned pixels, sequentially in descending order starting with pixels having a higher local amplitude on the basis of the estimated local amplitudes of ringing artifacts.