MRI Apparatus Fat Signal Separation via Multi-TE Pulse Sequences
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Solution Overview
Problem
Current magnetic resonance imaging techniques face challenges in accurately separating and quantifying signals of saturated and unsaturated fats, particularly olefinic fat, in two-dimensional or three-dimensional images, and existing methods like IDEAL do not account for multiple types of fat, leading to difficulties in high-resolution imaging and accurate fat constituent analysis.
Innovation Solution
A magnetic resonance imaging apparatus that employs sequence controlling circuitry to execute multiple pulse sequences with varying Echo Time (TE) values, allowing the processing circuitry to extract signals related to water and multiple types of fat by calculating coefficients based on chemical shift values, enabling the generation of 2D or 3D images that quantify aliphatic, olefinic, monounsaturated, and polyunsaturated fat signals effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single-voxel MRS method (PRESS) is used to quantify fat signals, then measurement precision of fat signals is improved, but the application is limited to single-voxel imaging and cannot provide 2D or 3D spatial distribution
Solution Approach 1:
The patent combines the advantages of single-voxel MRS (accurate fat signal quantification) with multi-voxel imaging capabilities. By integrating IDEAL decomposition methodology with pulse sequence design, it enables simultaneous achievement of precise fat signal separation and 2D/3D spatial distribution visualization across multiple voxels.
Solution Approach 2:
The imaging apparatus is designed to perform multiple functions: it can quantify different types of fat signals (saturated and unsaturated), provide spatial distribution information through 2D/3D imaging, and operate with flexible voxel configurations. This multi-functionality resolves the limitation of single-voxel methods while maintaining measurement precision.
2Device complexity
If IDEAL method is used for fat signal extraction assuming one type of fat, then device complexity is reduced, but measurement precision of multiple fat types deteriorates
Solution Approach 1:
The patent segments the fat signal analysis into distinct components by针对不同 types of fat (saturated vs. unsaturated) with different chemical shifts. The pulse sequence design and signal processing separately quantify each fat type, maintaining measurement precision while managing complexity through structured segmentation of the analysis process.
Solution Approach 2:
The methodology uses parameter changes in the pulse sequence (specifically echo time variations) to differentiate between multiple fat types. By acquiring images at multiple echo times and applying IDEAL decomposition, the system can separate and quantify different fat species based on their distinct magnetic resonance properties, achieving both precision and manageable complexity.
3Measurement precision
If multiple pulse sequences with different TE values are executed to separate water and multiple fat signals, then measurement precision of fat constituents is improved, but loss of time increases
Solution Approach 1:
The patent employs periodic action by executing pulse sequences at specifically designed echo time intervals. The IDEAL decomposition utilizes these periodic acquisitions at multiple TE values to mathematically separate water and different fat types, achieving high measurement precision while optimizing the time investment through efficient periodic sampling of the magnetic resonance signals.
4Measurement precision
If pulse sequences are optimized for water-fat separation, then measurement precision of fat signals is improved, but reliability of imaging in water-absent regions (pure fat tissues) deteriorates
Solution Approach 1:
The patent implements dynamic adaptability in its signal processing approach. The IDEAL decomposition methodology can dynamically adjust to different tissue compositions, whether water-rich or fat-dominant regions. By using multiple echo times and iterative decomposition, the system reliably separates and quantifies fat signals regardless of the presence or absence of water, maintaining measurement precision across diverse tissue types.
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 allows for the accurate separation and quantification of multiple types of fat signals in MRI images, improving resolution and enabling the analysis of fat constituents in tissues, even in the absence of water, by adjusting pulse sequences to optimize phase differences and chemical shift-based calculations.
Implementation Method 1
magnetic resonance imaging apparatus executes a first pulse sequence having a first Echo Time (TE) value
Implementation Method 2
extracts a signal related to water, a signal related to a first fat, and a signal related to a second fat, on the basis of the first piece of data, the second piece of data, and the third piece of data
Data Source
AI summary
A magnetic resonance imaging apparatus according to an embodiment includes sequence controlling circuitry and processing circuitry. The sequence controlling circuitry acquires a first piece of data by executing a first pulse sequence having a first Echo Time (TE) value, to acquire a second piece of data by executing a second pulse sequence having a second TE value different from the first TE value, and to acquire a third piece of data by executing a third pulse sequence having a third TE value different from the first and the second TE values. The processing circuitry extracts a signal related to water, a signal related to a first fat, and a signal related to a second fat, on the basis of the first piece of data, the second piece of data, and the third piece of data.