MRI Apparatus Using Combined Labeling Methods for Myocardial Perfusion Imaging
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Solution Overview
Problem
Current magnetic resonance imaging (MRI) techniques using Time-SLIP acquisition face limitations such as restricted observation areas due to single 2D acquisition processes and misregistration issues in 3D acquisitions, which hinder accurate imaging of blood perfusion in the myocardium.
Innovation Solution
The MRI system employs a combination of multiple labeling methods, including non-selective and selective IR pulses, to acquire multiple types of labeled images within a single breath-hold period, reducing misregistration and enhancing image accuracy by performing subtraction operations between these images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If single 2D acquisition process is used, then device complexity is reduced, but observation area is restricted and measurement precision deteriorates
Solution Approach 1:
The patent transitions from 2D acquisition to 3D acquisition to expand the observation area and improve measurement precision. By adding the temporal dimension and utilizing three-dimensional spatial encoding, the system can capture blood perfusion information throughout the entire myocardium volume, overcoming the limited observation area of 2D methods while maintaining manageable system complexity through standardized 3D pulse sequence implementation
2Area of stationary object
If 3D acquisition is used, then observation area is expanded, but misregistration issues occur and device complexity increases
Solution Approach 1:
The patent employs periodic labeling pulses applied at regular intervals during the 3D acquisition process. These periodic IR pulses label blood in a cyclic manner, creating temporally periodic signal patterns that can be distinguished from stationary tissue signals. This periodic action enables reliable separation of blood flow information from tissue background, resolving misregistration issues by providing temporal encoding that complements spatial encoding
Solution Approach 2:
The system uses feedback mechanisms to monitor and correct for motion-induced misregistration during 3D acquisition. By continuously tracking position information and comparing it against expected values, the system can apply real-time corrections to maintain registration accuracy across the expanded 3D observation volume, ensuring reliable blood perfusion measurement throughout the myocardium
3Measurement precision
If multiple labeling methods are combined, then image accuracy is improved and blood flow isolation is enhanced, but device complexity and processing time increase
Solution Approach 1:
The patent segments the labeling process into distinct types (non-selective IR pulses and selective IR pulses) that can be independently optimized and combined. Non-selective pulses label all blood in the field of view, while selective pulses label only blood in specific regions. By segmenting the labeling approach, the system achieves comprehensive blood flow coverage with improved accuracy while managing pulse sequence complexity through modular design of labeling modules that can be selected and combined based on specific imaging requirements
4Measurement precision
If multiple labeled images are acquired, then subtraction operations improve image clarity, but acquisition time and processing complexity increase
Solution Approach 1:
The patent merges multiple labeling methods and their corresponding acquisitions into a unified 3D pulse sequence framework. By combining non-selective and selective labeling approaches within a single integrated sequence, the system acquires multiple labeled images during one continuous breath-hold period rather than requiring separate acquisition sessions. This merging approach enables comprehensive blood flow characterization through subtraction operations while minimizing total acquisition time and maintaining patient comfort
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 more accurate visualization of myocardial perfusion and identification of regions of ischemia or infarction by isolating blood flow from myocardial signal contributions, improving image clarity and reducing registration errors.
Implementation Method 1
nuclei of a patient placed within a static magnetic field are magnetically excited by a high frequency (RF(radio frequency)) signal of the Larmor frequency and an image is reconstructed from magnetic resonance (MR) signals generated in accordance with the excitation
Implementation Method 2
The sequence controller executes a pulse sequence using a combination of multiple types of labeling methods to acquire magnetic resonance signals
Data Source
AI summary
A magnetic resonance imaging (MRI) apparatus according to an exemplary embodiment includes a sequence controller and a data processor. The sequence controller executes a pulse sequence using a combination of multiple types of labeling methods to acquire magnetic resonance signals. The data processor generates multiple types of labeled images based on the magnetic resonance signals.