Reduced Field of View MR Fingerprinting for High Resolution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional MRI techniques face challenges in achieving high-resolution imaging without increasing acquisition time or inducing geometrical distortion, as they rely on fixed excitation volumes and limited gradient strength, leading to blurred images.
Innovation Solution
The method involves acquiring MRF signals from multiple excitation volumes that partially overlap, allowing for comparison with a dictionary of signal evolutions to determine physical parameters, and varying the excited volume from frame to frame to achieve a reduced field of view, enabling higher spatial resolution with shorter readout gradients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional MRI uses fixed excitation volumes and limited gradient strength, then acquisition time is kept manageable, but spatial resolution deteriorates and images become blurred
Solution Approach 1:
The patent divides the imaging process into multiple segments by acquiring MRF signals from multiple different excitation volumes (first, second, third volumes) that partially overlap. Each volume is acquired separately and then combined through image registration and merging algorithms. This segmentation allows the system to achieve high spatial resolution by effectively increasing the total k-space coverage without requiring a single long readout gradient, thus maintaining reasonable acquisition time while improving resolution.
Solution Approach 2:
The patent transitions from a single fixed excitation volume approach to a multi-volume approach, adding the dimension of multiple spatial locations. By varying the excitation volume location and orientation across different acquisitions, the system samples k-space from multiple perspectives, effectively increasing resolution without proportionally increasing readout time in any single acquisition.
2Manufacturing precision
If conventional MRI increases gradient readout duration to achieve higher resolution, then spatial resolution improves, but geometrical distortion and image blurring increase
Solution Approach 1:
By segmenting the total k-space acquisition into multiple shorter readouts from different excitation volumes, the patent avoids the need for a single long gradient readout. Each individual readout remains short enough to minimize geometrical distortion and blurring, while the combination of multiple segmented acquisitions achieves the overall high resolution goal.
Solution Approach 2:
The patent employs dynamic variation of excitation volume parameters (location, orientation, size) across multiple acquisitions. This dynamic approach allows optimal sampling of k-space from different perspectives, achieving high resolution without requiring any single readout to be excessively long, thereby minimizing distortion effects.
3Adaptability or versatility
If MRF uses varied sequence blocks to produce different signal evolutions, then tissue characterization capability improves, but sequence complexity increases
Solution Approach 1:
The patent employs a universal MRF pulse sequence that can acquire signals from multiple different excitation volumes using the same basic sequence structure. Rather than requiring different specialized sequences for different volumes or parameters, the same versatile MRF sequence is applied repeatedly with varied excitation volume parameters, simplifying the overall system while maintaining comprehensive tissue characterization capability.
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 high-resolution parametric mapping with reduced acquisition time and minimized artifacts, enhancing the accuracy of tissue characterization and image quality.
Implementation Method 1
a magnet system configured to generate a polarizing magnetic field about at least a region of interest (ROI) of a subject
Implementation Method 2
a radio frequency (RF) system configured to apply an excitation field to the subject and acquire MRF signal evolutions from the ROI
Implementation Method 3
a plurality of gradient coils configured to apply a gradient field to the polarizing magnetic field
Data Source
AI summary
The present disclosure provides systems and methods for magnetic resonance fingerprinting (MRF). The method including steps comprising acquiring a plurality of MRF signals from a plurality of excitation volumes within a subject, wherein at least two of the plurality of excitation volumes differ in location within the subject, and wherein each of the excitation volumes partially overlap to form an overlap volume. The method also includes comparing the plurality of MRF signals acquired from the overlap volume with a dictionary of signal evolutions, determining one or more physical parameters of the overlap volume within the subject, and generating a report at least indicating the one or more physical parameters of the overlap volume within the subject.