PROPELLER MRI Water-Fat Separation via Dixon Technique

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

PROPELLER MRI methods are sensitive to image artifacts such as main B0 field inhomogeneities and motion, leading to motion and fat-water separation challenges, especially at higher field strengths and in body applications.

Innovation Solution

A method for acquiring and processing multiple sets of k-space blade data using a Dixon technique, incorporating water-fat shift correction and B0 field inhomogeneity mapping to improve fat suppression and motion correction, combining PROPELLER and Dixon techniques for robust image acquisition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PROPELLER MRI method is used to minimize motion and pulsation oversampling, then motion robustness is improved, but sensitivity to B0 field inhomogeneities and image artifacts increases

Engineering Contradiction:
Improvemotion robustnessVSAvoidB0 field inhomogeneity sensitivity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent combines PROPELLER MRI method with Dixon water-fat separation technique to simultaneously achieve motion robustness and B0 field inhomogeneity compensation. The integration allows the system to utilize the motion correction capabilities of PROPELLER while incorporating the field inhomogeneity correction capabilities of Dixon method through multi-echo acquisition and iterative reconstruction

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs multiple echo times (TE1, TE2, TE3) to acquire k-space blade data at different phases, enabling the system to capture water and fat signals at different magnetic resonance phases. This parameter variation allows subsequent separation of water and fat components and correction of B0 field inhomogeneities through iterative reconstruction algorithms

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If Dixon technique is applied for water-fat separation, then fat suppression is improved, but acquisition time and processing complexity increase

Engineering Contradiction:
Improvewater-fat separation accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the k-space acquisition into multiple blades, where each blade is acquired at multiple echo times. This segmentation allows the Dixon water-fat separation to be performed independently for each blade, reducing the overall computational complexity compared to processing the entire k-space at once, while maintaining accurate water-fat separation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary water-fat separation and B0 field mapping during the iterative reconstruction process by acquiring k-space data at multiple echo times. This preliminary action enables the system to separate water and fat components before final image reconstruction, simplifying the overall processing pipeline and reducing final reconstruction complexity

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If multiple echo times are used for Dixon water-fat separation, then water-fat separation accuracy is improved, but scan time increases

Engineering Contradiction:
Improvewater-fat separation accuracyVSAvoidscan time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent acquires k-space blade data continuously at multiple echo times without interrupting the scan sequence. This continuous acquisition approach allows the system to collect all necessary data for water-fat separation in a single pass, minimizing scan time while maintaining high separation accuracy through efficient use of each acquired blade

Inventive Principle:
Principle #20Continuity of useful action

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 provides motion-robust imaging with reduced fat and off-resonance artifacts, enabling effective water and fat separation and suppression, particularly beneficial in body imaging and at higher field strengths.

Implementation Method 1

acquire k-space blade data using at least one echo time for purposes of performing a Dixon technique

Methodology Applied
Scientific EffectDixon water-fat separation: Phase Change

Implementation Method 2

magnetic resonance imaging system

Methodology Applied
Scientific EffectMagnetic resonance: Resonance

Implementation Method 3

incorporating water-fat shift correction

Methodology Applied
Scientific EffectChemical shift: Lorentz Force

Implementation Method 4

B0 field inhomogeneity mapping to improve fat suppression and motion correction

Methodology Applied
Scientific EffectB0 field inhomogeneity: Magnetic Field

Data Source

PatentEP2893363B1Propeller with dixon water fat separation
Publication Date: 2020.08.19 KONINKLIJKE PHILIPS NV
  • EP2893363B1 patent drawingFigure 1
  • EP2893363B1 patent drawingFigure 2
  • EP2893363B1 patent drawingFigure 3

AI summary

The invention relates to a magnetic resonance imaging system (100) for acquiring at least one set of k-space blade data from an imaging zone of a subject (118), wherein the magnetic resonance imaging system (100) comprises a memory (138) for storing machine executable instructions and a processor (130) for controlling the magnetic resonance imaging system (100), wherein execution of the machine executable instructions causes the processor (130) to perform for each blade of the at least one set of k-space blade data: control the MRI system (100) to acquire at least one k-space blade data using at least one echo time for purposes of performing a Dixon technique, wherein k-space blade data are acquired in accordance with a blade shape; reconstruct at least one blade image data using the at least one k-space blade data; generate water blade image data and fat blade image data using the at least one blade image data; and transform the water and fat blade image data to water and fat k-space blade data respectively and perform PROPELLER reconstruction of the water and fat k-space blade data.