SMS MRI Artifact Reduction via Localized Parameter Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current simultaneous multi-slice (SMS) MRI imaging techniques suffer from artifacts such as slice-leakage, which occur due to spatial mismatch between image data and coil sensitivity maps, particularly at air-tissue interfaces, leading to incorrect disease diagnosis.
Innovation Solution
The MRI system optimizes SMS sequence parameters by estimating distorted regions and adjusting parameters like slice shift, multi-band factor, and stack combinations to minimize artifact presence, using algorithms to compute optimized values and reconstruct images with reduced artifact presence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If simultaneous multi-slice MRI imaging is performed with standard SMS sequence parameters, then imaging productivity is improved by acquiring multiple slices simultaneously, but image quality deteriorates due to artifact presence such as slice-leakage at air-tissue interfaces
Solution Approach 1:
The patent applies local quality by estimating distorted regions in each slice and applying slice-specific shift amounts rather than uniform shifts across all slices. This allows the imaging system to adapt the SMS sequence parameters locally to minimize artifacts in distorted regions while maintaining productivity in non-distorted regions.
Solution Approach 2:
The patent changes the SMS sequence parameters, specifically the slice shift amount, based on estimated distorted regions. By dynamically adjusting the shift amount for each slice according to its distortion characteristics, the system resolves the contradiction between maintaining high imaging productivity and achieving high image quality without artifacts.
2Device complexity
If fixed SMS sequence parameters are used for all slices, then device complexity is reduced by simplifying the imaging protocol, but measurement precision deteriorates due to spatial mismatch between image data and coil sensitivity maps
Solution Approach 1:
The patent performs preliminary action by estimating distorted regions and computing optimized shift amounts for each slice before the actual SMS imaging sequence is executed. This pre-processing step allows the system to determine slice-specific parameters in advance, improving spatial alignment accuracy without significantly increasing the complexity of the main imaging protocol.
Solution Approach 2:
The system performs self-service by automatically estimating distorted regions and computing optimized SMS sequence parameters without requiring manual intervention. The imaging system adapts to each slice's characteristics autonomously, maintaining measurement precision while keeping the device complexity manageable through automated algorithms.
3Ease of operation
If uniform slice shift amounts are applied to all slices, then ease of operation is improved by simplifying parameter configuration, but reliability deteriorates due to incorrect disease diagnosis from artifact presence
Solution Approach 1:
The patent implements feedback by using the estimated distorted regions to determine optimized slice shift amounts for each slice. The system automatically adjusts parameters based on the actual distortion characteristics observed in each slice, ensuring reliable diagnostic images without requiring complex manual configuration, thus maintaining ease of operation while improving reliability.
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 significantly reduces artifact presence in SMS images, enhancing diagnostic accuracy and precision by aligning image data with coil sensitivity maps, especially in regions prone to distortion.
Implementation Method 1
Magnetic resonance imaging (MRI) is an imaging scan method that magnetically excites nuclear spins of a subject placed in a magnetostatic field by a radio frequency (RF) pulse having a Larmor frequency thereof, to generate an image from magnetic resonance signal data generated with the excitation.
Data Source
AI summary
A magnetic resonance imaging system includes an array radiofrequency coil and processing circuitry operatively linked to the array radiofrequency coil and configured to receive output signals from the array radiofrequency coil commensurate with a simultaneous multi-slice magnetic imaging characterized by simultaneous multi-slice parameters, estimate distorted regions of the image volume using either data obtained via a pre-scan or a pre-computed model, minimize overlap of the distorted regions with image voxels representing tissue to obtain optimized values of the simultaneous multi-slice parameters, configuring and executing the simultaneous multi-slice imaging sequence based on the optimized values of the simultaneous multi-slice parameters, and reconstruct simultaneous multi-slice images with minimized artifacts.