MRI Respiratory Artifact Reduction via K-Space Sorting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic resonance imaging (MRI) scans are often hindered by patient respiration, leading to artifacts in MR images due to incomplete breath-holding, especially during longer scanning sequences, as existing methods like prospective and retrospective gating have limitations in efficiency and accuracy.
Innovation Solution
A magnetic resonance imaging apparatus and method that randomly determines the number and order of data acquisition in consideration of the patient's respiration cycle, using a sequence controller to acquire multiple MR signals within a single respiration cycle with varying Y-axis gradient magnetic fields, and a data processor to classify and reconstruct k-space data using compressive sensing techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If the imaging sequence time is extended to capture more diagnostic information, then the diagnostic value is improved, but the patient's ability to hold breath is exceeded, causing respiration artifacts
Solution Approach 1:
The patent segments the k-space data acquisition into multiple respiratory cycles, collecting data from different respiratory phases and reconstructing images for each phase separately. This allows the imaging sequence to extend beyond a single breath-hold while maintaining image quality by grouping data according to respiratory condition.
Solution Approach 2:
The patent changes the parameter of data selection criteria by using respiratory condition (inspiration/expiration state) as the basis for grouping k-space data, rather than requiring all data to be acquired during a single breath-hold. This enables extended imaging sequences while reducing respiratory artifacts through conditional data sorting.
2Object-affected harmful factors
If prospective gating or retrospective gating is used to reduce respiratory artifacts, then image quality is improved, but data acquisition efficiency is reduced
Solution Approach 1:
The patent employs a self-navigator method where the system automatically identifies respiratory phases using internal reference signals from the acquired data itself, without requiring external gating hardware or complex prospective gating protocols. This maintains data acquisition efficiency while reducing respiratory artifacts through automated data sorting.
3Quantity of substance
If multiple MR signals are acquired for the same Y-axis gradient magnetic field in a single respiration cycle, then data completeness is improved, but the complexity of data processing increases
Solution Approach 1:
The patent performs preliminary sorting and classification of acquired MR signals according to their corresponding respiratory conditions before reconstruction. By organizing data into inspiration and expiration groups in advance, the system simplifies the subsequent reconstruction process while ensuring complete utilization of acquired data.
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 enhances data acquisition efficiency and reduces respiratory artifacts in MRI images by ensuring data is acquired across multiple respiration conditions, improving image quality and resolution.
Implementation Method 1
a scanner forming a X-axis gradient magnetic field, a Y-axis gradient magnetic field, and a Z-axis gradient magnetic field in a bore
Implementation Method 2
acquire N (N is an integer of 2 or more) MR signal for the same Y axis gradient magnetic field in a single respiration cycle Tresp of the patient at the same interval Tresp/N
Data Source
AI summary
A magnetic resonance imaging (MRI) apparatus and a control method thereof are provided. The MRI apparatus includes a scanner, and a controller configured to control the scanner to receive magnetic resonance (MR) signals corresponding to a magnitude of a y-axis gradient magnetic field in a respiration cycle of a patient, each of the MR signals being received at a time interval equal to a time period of the respiration cycle over a number of the received MR signals. The MRI apparatus further includes a processor configured to extract an MR signal received in a respiration condition of the patient from the received MR signals, fill a k-space with the extracted MR signal, and generate an MR image by reconstructing data of the filled k-space.