Dual-Echo Arteriovenography Slab Boundary Artifact Reduction
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Solution Overview
Problem
Existing methods for acquiring arteriograms and venograms simultaneously using dual-echo arteriovenography face challenges in optimizing the number of slabs and often result in artifacts at slab boundaries, particularly when using conventional time-of-flight MR angiography with multiple slabs.
Innovation Solution
A data acquisition method involving multiple echoes is employed, where RF pulses are excited for specific slabs and the entire slab, with each echo acquiring low and high-frequency components in predetermined orders, allowing for the generation of optimized arteriogram and venogram images by combining phase encoding lines in specific image regions and frequency domains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple slabs are used for time-of-flight MR angiography, then blood vessel detection is improved, but artifacts occur at slab boundaries and SNR deteriorates
Solution Approach 1:
The imaging space is divided into multiple slabs along the phase encoding direction, with each slab excited by dedicated RF pulses. This segmentation allows independent optimization of each slab's acquisition parameters while maintaining overall coverage, resolving the conflict between comprehensive vessel detection and boundary artifact reduction
Solution Approach 2:
Different acquisition strategies are applied to different regions: central k-space lines (low frequency) are acquired with longer TR for better SNR in regions requiring high contrast, while peripheral k-space lines (high frequency) use shorter TR for faster acquisition. This local quality differentiation optimizes both vessel detection and artifact suppression in respective regions
2Measurement precision
If one slab is used for BOLD MR venogram, then SNR is improved, but comprehensive venous coverage is reduced
Solution Approach 1:
The imaging volume is segmented into multiple slabs that collectively cover the entire region of interest. Each slab is acquired with optimized parameters for BOLD contrast, and the segments are later combined to achieve both comprehensive venous coverage and high SNR through coordinated acquisition
Solution Approach 2:
Data from multiple slab acquisitions are merged in k-space with appropriate phase corrections and intensity normalization. This combining process achieves comprehensive venous coverage while maintaining high SNR by integrating signals from all slab regions rather than relying on a single slab
3Area of stationary object
If multiple slabs are used simultaneously for dual-echo arteriovenography, then both arteriogram and venogram coverage are improved, but optimization of slab number becomes complex and time-consuming
Solution Approach 1:
The system dynamically adjusts acquisition parameters including slab thickness, number of slabs, TR, and TE based on the selected imaging mode (arterial, venous, or dual). These parameter changes are automatically configured according to predetermined protocols, simplifying the optimization process while maintaining comprehensive coverage and reducing manual configuration complexity
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 simultaneous acquisition of optimized arteriograms and venograms in one shot, reducing artifacts at slab boundaries and improving image quality by aligning the shooting conditions for each echo, thereby enhancing the connectivity and quality of the arteriogram.
Implementation Method 1
Magnetic resonance image is an imaging technique that uses the principle of nuclear magnetic resonance. When the human body is put into a magnetic resonance imaging apparatus that generates a magnetic field and generates a high frequency, electrons of hydrogen atoms in the body resonate.
Implementation Method 2
generating a first low frequency sub-image 511 by transforming first low frequency phase encoding lines 211 acquired from the first echoes of the first process into an image region
Implementation Method 3
generating first high frequency sub-images 721 by transforming first high frequency phase encoding lines 221 acquired from the second echoes of the first process into an image region
Data Source
AI summary
The present invention relates to a method for acquiring data for acquiring an arteriogram and a venogram of magnetic resonance imaging, the method: using one or more echo; and simultaneously acquiring, through one-time photography, an arteriogram and a venogram, which are optimized according to the number of slabs or improving connectivity of a slab boundary part of the arteriogram.