MRI Ky-kz Plane Segmentation for Contrast and Speed
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current magnetic resonance imaging (MRI) techniques that divide the ky-kz plane into numerous segments to reduce imaging time compromise image contrast, and methods to shorten imaging time by combining lines orthogonal to the kz axis in one segment result in reduced contrast.
Innovation Solution
The MRI apparatus divides the ky-kz plane into z segments, with center-in and center-out regions defined by radial lines, where data are acquired using first and second trajectories, respectively, allowing for a wider angle in center-out regions than center-in regions, thereby increasing data density and reducing the total number of segments, thus shortening imaging time while maintaining high contrast.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the ky-kz plane is divided into numerous segments to reduce imaging time, then imaging time is shortened, but image contrast is reduced
Solution Approach 1:
The ky-kz plane is divided into multiple segments, with each segment containing center-in and center-out regions. This segmentation allows for optimized data acquisition within each segment, enabling shorter imaging time while maintaining image contrast through the specific trajectory design in each segment.
Solution Approach 2:
Different regions within segments (center-in and center-out) use different trajectory types. The center-in region uses trajectories proceeding toward the center of the ky-kz plane, while the center-out region uses trajectories proceeding away from the center. This local differentiation optimizes data acquisition for both contrast and efficiency.
2Loss of time
If two lines orthogonal to the kz axis are contained in one segment to shorten imaging time, then imaging time is reduced, but image contrast is reduced
Solution Approach 1:
The trajectory direction changes dynamically within each segment. Data acquisition starts with trajectories proceeding toward the center (center-in region), then transitions to trajectories proceeding away from the center (center-out region). This dynamic trajectory adjustment allows more lines to be acquired per segment while maintaining contrast.
3Productivity
If the angle of center-in region at the center of the ky-kz plane is made wider to increase data density, then data acquisition efficiency is improved, but the angle of center-out region must be reduced
Solution Approach 1:
The center-in and center-out regions are designed with asymmetric angular configurations. The center-in region has a specific angle at the center of the ky-kz plane, while the center-out region has a different angle. This asymmetric design optimizes the balance between data acquisition efficiency and trajectory manageability.
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 a reduction in the number of segments, shortening imaging time while ensuring high-contrast images by adjusting the data distribution in center-in and center-out regions, allowing for efficient data acquisition with improved image quality.
Implementation Method 1
magnetic resonance imaging apparatus that acquires magnetic resonance signals from a subject
Data Source
AI summary
A magnetic resonance imaging apparatus includes z segments which divide a ky-kz plane. The z segments includes data located therein. The ky-kz plane is divided into z center-in regions and z center-out regions by a plurality of lines extending radially from a center of the ky-kz plane. The z center-in regions have data located therein in accordance with first trajectories which proceed toward the center of the ky-kz plane. The z center-out regions have data located therein in accordance with second trajectories which proceed in a direction spaced away from the center of the ky-kz plane. Each of the z segments has one center-in region of the z center-in regions and one center-out region of the z center-out regions. Each of the z segments is defined in which after data have been located in said one center-in region in accordance with the first trajectory, data are located in said one center-out region in accordance with the second trajectory. At least one of the z segments is defined in which an angle of said one center-in region at the center of the ky-kz plane is wider than an angle of said one center-out region at the center of the ky-kz plane.