Diffusion-Weighted FSE and GRASE MRI Sequences for Nanoconstruct Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current MRI techniques, such as single-shot echo-planar imaging, require high-performance gradient coils and are sensitive to field inhomogeneities and motion artifacts, limiting their efficiency and image quality, especially in diffusion-weighted imaging.
Innovation Solution
The use of diffusion-weighted fast-spin echo (FSE) and gradient-and-spin echo (GRASE) processes with nanoconstructs having a specific molecular weight and T2 relaxation time, combined with diffusion filtering and optimized signal acquisition bandwidth, to suppress water signals and selectively image MRI agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If single-shot echo-planar imaging is used, then scan time is reduced, but image quality deteriorates due to sensitivity to field inhomogeneities and motion artifacts
Solution Approach 1:
The patent changes the imaging parameters by using diffusion-weighted fast-spin echo or GRASE sequences instead of echo-planar imaging, adjusting the pulse sequence parameters to achieve both rapid acquisition and reduced sensitivity to field inhomogeneities and motion artifacts
Solution Approach 2:
The patent introduces diffusion filtering as an intermediary mechanism that selectively suppresses water signals while preserving signals from nanoconstructs, thereby improving image quality without requiring prolonged scan times
2Measurement precision
If diffusion filtering is applied to suppress water signals, then water signal suppression is improved, but signal acquisition complexity increases
Solution Approach 1:
The patent optimizes the diffusion filtering parameters (b-value, gradient strength, duration) to achieve effective water signal suppression while maintaining a practical level of system complexity that can be implemented on standard MRI scanners
3Measurement precision
If optimized signal acquisition bandwidth is used, then image quality is improved, but scan time increases
Solution Approach 1:
The patent optimizes the signal acquisition bandwidth parameter to balance image quality and scan time, selecting a bandwidth that provides sufficient signal resolution while maintaining efficient data acquisition rates
Solution Approach 2:
The patent employs fast-spin echo or GRASE sequences that continuously acquire multiple echoes following a single excitation pulse, maintaining continuous useful action during signal acquisition to reduce overall scan time while preserving image quality
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 improved visualization of MRI agents and tumors with reduced scan time, enhanced image quality, and increased patient throughput by effectively suppressing water and fat signals, enabling clearer imaging of nanoconstructs at low concentrations.
Implementation Method 1
applying diffusion filtering in range of about 500 to about 10,000 s/mm2 to suppress water signals from the scan and selectively imaging the nanoconstructs
Implementation Method 2
the nanoconstructs each have a T2 relaxation time greater than at least about 250 ms
Implementation Method 3
obtain a diffusion-weighted fast-spin echo (FSE) or gradient-and-spin echo (GRASE) nuclear magnetic resonance scan of the nanoconstructs
Data Source
AI summary
Methods for imaging magnetic resonance imaging (MRI) agents containing nanoconstructs therein using diffusion-weighted fast-spin echo (FSE) or gradient-and-spin echo (GRASE) processes are described herein.