K-space Trajectory Correction for MRI Gradient Deviations

Solution Overview

Problem

Magnetic resonance imaging (MRI) systems face challenges in correcting deviations in gradients during the readout process, leading to artifacts due to imperfections in gradient coils and eddy currents, which existing methods inadequately address with inflexible and computationally intensive methods.

Innovation Solution

A method that loads frequency-dependent parameters characterizing the gradient unit and corrects k-space trajectories by adjusting frequency components of planned trajectories, allowing for flexible and efficient correction of gradient deviations with minimal computational effort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If inflexible correction methods are used to address gradient deviations, then measurement precision is improved, but device complexity and computational effort increase significantly

Engineering Contradiction:

Improveaccuracy of k-space trajectory correctionVSAvoidcomputational complexity of correction method

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transforms the correction problem from the time domain to the frequency domain by applying Fourier transforms. This parameter transformation allows the correction method to operate on frequency components rather than time-domain signals, simplifying the mathematical operations required and reducing computational complexity while maintaining correction accuracy

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces complex time-domain correction algorithms with a frequency-domain approach using Fourier transforms. This substitution changes the mathematical mechanism from iterative time-domain processing to efficient frequency-domain multiplication and transformation, significantly reducing computational burden

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If frequency-domain correction method is applied, then computational effort is reduced, but measurement precision may be compromised

Engineering Contradiction:

Improvespeed of correction processingVSAvoidaccuracy of gradient deviation correction

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent replaces complex time-domain correction algorithms with a frequency-domain approach using Fourier transforms. This substitution changes the mathematical mechanism from iterative time-domain processing to efficient frequency-domain multiplication and transformation, significantly reducing computational burden

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transforms the correction problem from the time domain to the frequency domain by applying Fourier transforms. This parameter transformation allows the correction method to operate on frequency components rather than time-domain signals, simplifying the mathematical operations required and reducing computational complexity while maintaining correction accuracy

Inventive Principle:

Principle #35Parameter changes

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 effectively reduces artifacts by accurately correcting gradient deviations, enabling faster and more accurate MRI data acquisition with reduced computational burden, improving image quality and measurement efficiency.

Implementation Method 1

deviations in gradients actually generated during a measurement during a readout period from the respective ideal gradients planned for this readout period, leading to artifacts due to imperfections in gradient coils and eddy currents

Methodology Applied

Scientific EffectEddy currents: Eddy Currents

Data Source

PatentUS11604240B2Method for recording measurement data using a magnetic resonance system with a correction of k-space trajectories

Publication Date: 2023.03.14 SIEMENS HEALTHINEERS AG

AI summary

In a method for recording measurement data, frequency-dependent parameters characterizing a gradient unit are loaded, a k-space trajectory planned for a MR measurement and having at least one frequency component is loaded, MR measurement data is acquired based on the planned k-space trajectory and reconstructing image data from the MR measurement data, wherein the planned k-space trajectory is corrected based on the at least one frequency component of the planned k-space trajectory and the frequency-dependent parameters, and an electronic signal representing the reconstructed image data is provided as an output of the MR system. The reconstructed image data may be stored and/or displayed. Advantageously, the correction can be employed flexibly for k-space trajectories with different frequency components.