MRI Phase Correction Using Prescan Data to Prevent Signal Cancellation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic resonance imaging (MRI) systems with high main magnet field strengths, lacking a body coil, face challenges in generating high-quality images due to signal cancellations caused by the absence of reference phase information, particularly in regions not covered by the best available coil element.
Innovation Solution
A method for generating an imaging image dataset that involves acquiring prescan and imaging raw datasets with multiple coil elements, reconstructing single coil images, and combining them while establishing phase values without phase jumps to create a combined prescan and imaging dataset, allowing for efficient coil combination without the need for a reference phase information item.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If local coils are used instead of a body coil in high field strength MRI systems, then the MRI system can achieve high field strength imaging, but reference phase information cannot be obtained leading to signal cancellations
Solution Approach 1:
The patent applies preliminary action by acquiring prescan raw datasets before the actual imaging scan to establish reference phase information. The phase values are determined in advance from prescan data, then used during the subsequent imaging scan to correct phase variations and prevent signal cancellations, ensuring high image quality without requiring a body coil
Solution Approach 2:
The patent uses an intermediary approach by introducing a computing unit that processes prescan data to extract phase values. This computing unit acts as an intermediary between the local coils and the final image reconstruction, using the extracted phase values to correct imaging data and eliminate signal cancellations caused by the absence of a body coil
2Measurement precision
If the best available coil element is used as reference, then the coil element with maximum signal intensity is utilized, but regions not covered by this coil element cannot determine reference phase information causing signal cancellations
Solution Approach 1:
The patent merges data from multiple coil elements by combining their individual phase information into a comprehensive reference phase map. Instead of relying on a single best coil element, the system combines prescan data from all coil elements to establish complete phase coverage across the entire imaging region, eliminating gaps in phase information
Solution Approach 2:
The system performs preliminary scanning with all coil elements to establish reference phase information before the actual imaging scan. This prescan phase information is stored and applied during imaging to ensure complete phase correction coverage across all regions, not just where the best coil element has maximum signal
3Device complexity
If adaptive coil combination is applied directly to imaging raw data, then no reference phase information item is needed, but very large computation effort is required
Solution Approach 1:
The patent extracts only the essential phase information from the prescan data, separating this critical parameter from the full imaging dataset. By extracting and storing only phase values in advance, the system eliminates the need for complex adaptive coil combination during imaging while minimizing computation effort during the actual scan
Solution Approach 2:
The system performs the computationally intensive phase extraction and analysis during the prescan phase, before the actual imaging scan. This preliminary computation prepares phase correction data that can be efficiently applied during imaging, avoiding large computation efforts during the time-critical imaging acquisition
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 efficient and high-quality image generation in MRI systems without a body coil, reducing signal cancellations and computational effort, by using phase values from prescan datasets to correct and combine imaging data from local coil elements effectively.
Implementation Method 1
high frequency (RF) transmitted pulses may be radiated into the examination object, in accordance with a magnetic resonance protocol, with the aid of a high frequency antenna unit of the magnetic resonance apparatus and thus generate a B1 field
Implementation Method 2
The magnetic resonance signals are received by a high frequency receiving unit of the magnetic resonance apparatus as raw data
Data Source
AI summary
A method for generating an imaging image dataset includes: acquiring a plurality of prescan raw datasets; generating a plurality of prescan single coil image datasets by reconstructing the one prescan raw dataset in each case; generating a combined prescan image dataset by combining the plurality of prescan single coil image datasets, wherein the generation of the combined prescan image dataset includes an establishment of a plurality of phase values, each of which is associated with an image element of the combined prescan image dataset; acquiring a plurality of imaging raw datasets, each with one of the plurality of coil elements; generating a plurality of imaging single coil image datasets by reconstructing the one imaging raw dataset in each case; and generating a combined imaging image dataset by combining the plurality of imaging single coil image datasets while taking account of the phase values of the combined prescan image dataset.