Ultra-short TE MRI Pulse Sequence for Tissue Electrical Property Mapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current MRI methods for determining tissue conductivity and permittivity are slow and inefficient, requiring two separate acquisitions and resulting in low signal-to-noise ratio (SNR), which limits their clinical utility and availability on all scanners.
Innovation Solution
A method using a single, ultra-short echo time (TE) pulse sequence in MRI systems to acquire a complex B1+B1− quantity, allowing for the estimation of tissue conductivity and permittivity with improved SNR efficiency and reduced de-phasing, enabling faster and more accurate reconstruction of tissue electrical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If two separate MRI acquisitions are used to determine tissue conductivity and permittivity, then measurement precision is improved, but acquisition time increases and signal-to-noise ratio decreases
Solution Approach 1:
The patent combines the measurement of transmit field magnitude and phase into a single MRI acquisition using a dual-echo pulse sequence. This merges two separate acquisitions (one for magnitude mapping, one for phase mapping) into one simultaneous acquisition, reducing total acquisition time while maintaining measurement precision for both conductivity and permittivity determination.
Solution Approach 2:
The patent employs preliminary action by using a dual-echo pulse sequence that simultaneously acquires both magnitude and phase information in a single excitation cycle. The first echo provides magnitude information while the second echo provides phase information, allowing both measurements to be prepared and acquired in advance within one acquisition sequence rather than requiring separate sequential acquisitions.
2Measurement precision
If two separate MRI acquisitions are used to determine tissue conductivity and permittivity, then measurement precision is improved, but signal-to-noise ratio deteriorates
Solution Approach 1:
The patent merges two separate acquisitions into one dual-echo sequence, thereby maintaining the signal-to-noise ratio benefits of a single acquisition while still obtaining both magnitude and phase information. This avoids the cumulative noise that would result from performing two separate acquisitions sequentially.
Solution Approach 2:
The patent ensures continuity of useful action by maintaining a consistent single-acquisition protocol where both magnitude and phase measurements are obtained continuously within one pulse sequence. This continuous acquisition approach preserves signal-to-noise ratio by avoiding the interruptions and re-positioning required between separate acquisitions.
3Adaptability or versatility
If conventional MRI sequences are used for transmit field mapping, then adaptability is improved, but signal-to-noise ratio efficiency deteriorates
Solution Approach 1:
The patent achieves universality by developing a dual-echo pulse sequence that can be implemented on standard MRI scanners without requiring specialized hardware. The sequence uses conventional transmit and receive coils in a standard manner, making it adaptable to existing scanner platforms while achieving superior signal-to-noise ratio efficiency through the dual-echo acquisition strategy.
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 enables the determination of tissue conductivity and permittivity in clinically acceptable time frames with improved SNR, reducing de-phasing and eddy currents, and providing better reconstruction of tissue electrical properties with minimal hardware imperfections.
Implementation Method 1
MRI utilizes hydrogen nuclear spins of the water molecules in the human body, which are polarized by a strong, uniform, static magnetic field of a magnet. This magnetic field is commonly referred to as B0 or the main magnetic field.
Implementation Method 2
When excited by an RF wave, the spins precess about the main magnetic field at a characteristic Larmor frequency.
Implementation Method 3
A signal is emitted by the excited spins and processed to form an image.
Data Source
AI summary
Systems and methods for determining electrical properties using Magnetic Resonance Imaging (MRI) are provided. One method includes applying an ultra-short echo time (TE) pulse sequence in a Magnetic Resonance Imaging (MRI) system and acquiring a complex B1+B1− quantity from an object following the application of the ultra-short TE pulse sequence, where B1+ is a complex amplitude of a transmit radio-frequency (RF) magnetic field and B1− is a complex amplitude of a receive RF magnetic field. The method also includes estimating, with a processor, one or more electrical properties of the object using the complex amplitudes of the transmit RF magnetic field and the receive RF magnetic field.