MRI Phase Correction from Partial Slice Reference Scans
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Solution Overview
Problem
Conventional magnetic resonance echo planar imaging (EPI) techniques suffer from phase inconsistency between odd and even echoes due to factors like eddy currents and gradient delays, leading to Nyquist artifacts in reconstructed images, and existing phase correction methods require full-slice reference scans that are time-consuming and costly.
Innovation Solution
A magnetic resonance scanning and imaging method that performs a reference scan on a subset of slice positions, generating phase correction coefficients for all positions, thereby reducing reference scan time while suppressing Nyquist artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a reference scan is performed on all slice positions to acquire phase correction coefficients, then phase correction accuracy is improved, but reference scan time increases
Solution Approach 1:
The patent divides the slice positions into multiple groups and performs reference scans only on a subset of groups rather than all slice positions. This segmentation approach allows the system to acquire phase correction coefficients for unscanned slice positions through interpolation or prediction models, thereby reducing reference scan time while maintaining phase correction accuracy.
Solution Approach 2:
The patent applies partial action by performing reference scans only on a portion of slice positions (not all positions) to acquire phase correction coefficients. The system then extends these coefficients to unscanned positions using computational methods, achieving sufficient phase correction without the full reference scan time cost.
2Speed
If conventional EPI technique is used for fast imaging, then imaging speed is improved, but phase inconsistency and Nyquist artifacts increase
Solution Approach 1:
The patent performs preliminary reference scans on a subset of slice positions to acquire phase correction coefficients before the actual diagnostic scan. These pre-acquired coefficients are then used to correct phase inconsistencies during the main imaging process, allowing fast EPI imaging while suppressing Nyquist artifacts through pre-computed phase correction.
Solution Approach 2:
The system uses the phase correction coefficients obtained from reference scans as feedback to correct phase inconsistencies during the diagnostic scan. The coefficients serve as a reference that feeds back into the image reconstruction process, enabling real-time phase correction and artifact suppression while maintaining fast imaging speeds.
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
The method effectively reduces reference scan time and suppresses Nyquist artifacts by using phase correction coefficients derived from a partial slice scan, enhancing image quality without the need for full-slice reference scans.
Implementation Method 1
The transmit/receive coil generates a radio-frequency excitation signal to excite a scanned subject to generate a magnetic resonance signal
Implementation Method 2
by means of spatial encoding, the transmit/receive coil acquires the magnetic resonance signal
Data Source
AI summary
A magnetic resonance scanning and imaging method and a magnetic resonance imaging system are provided. The method includes: performing a reference scan on a site to be examined, acquiring reference scan data corresponding to a portion of slice positions among a plurality of slice positions, and generating, according to the reference scan data, a phase correction coefficient corresponding to each slice position among the plurality of slice positions; and performing, according to the phase correction coefficients, a diagnostic scan on the site to be examined to acquire a magnetic resonance image.