Magnetic Resonance Fingerprinting Iterative Signal Comparison

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Magnetic resonance fingerprinting (MRF) methods face limitations in determining parameter values, particularly the local magnetic field B0, due to artifacts such as banding and blurring, which affect spatial resolution and accuracy in clinical applications.

Innovation Solution

An iterative signal comparison method is employed to improve the determination of parameter values by correcting picture element time series based on initial parameter determinations, using comparison signal curves to refine measurements and account for measurement-specific parameters like B0, thereby increasing precision and reducing artifacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional MRF methods are used to determine parameter values, then measurement speed is improved, but measurement precision deteriorates due to artifacts like banding and blurring

Engineering Contradiction:
Improvemeasurement speedVSAvoidparameter value determination precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent segments the determination process into multiple stages: first determining a preliminary parameter value, then using this to correct the picture element time series, and finally determining an improved parameter value. This multi-stage segmentation allows the method to maintain fast measurement speed while improving precision by addressing artifacts systematically in separate processing steps.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary determination of parameter values and preliminary correction of picture element time series before the final precise measurement. By performing these preliminary actions first, the method prepares the data to reduce artifacts like banding and blurring, enabling the subsequent precise measurement to achieve better accuracy without sacrificing measurement speed.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If quantitative MR imaging techniques are used to determine absolute properties, then measurement precision is improved, but measurement time increases

Engineering Contradiction:
Improveabsolute property determination precisionVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies partial action by performing selective corrections only on picture element time series that require it, based on the preliminary parameter determination. Rather than applying full quantitative imaging processing to all data, the method selectively corrects and re-determines parameters only where needed, reducing overall measurement time while maintaining precision for critical measurements.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent implements a feedback mechanism where the preliminary parameter determination results are used to correct the picture element time series, which then feeds into the final parameter determination. This feedback loop allows the method to iteratively improve precision without requiring multiple separate measurements, thereby reducing total measurement time while achieving accurate absolute property determination.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If picture element time series are corrected based on preliminary parameter determination, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveparameter value determination precisionVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements self-service by using the data and parameter determinations already obtained during the measurement process to correct and improve the same data. The preliminary parameter values derived from the picture element time series are used to correct those same time series, eliminating the need for external calibration data or additional correction measurements, thereby improving precision without proportionally increasing system complexity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent merges the correction step with the parameter determination process by integrating the preliminary parameter determination, time series correction, and final parameter determination into a unified workflow. This merging allows the system to achieve improved precision through multiple processing stages without requiring separate complex subsystems, as the same processing unit handles all stages sequentially.

Inventive Principle:
Principle #5Merging (Combining)

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 the spatial resolution and precision of parameter value determination, allowing for more accurate assessment of tissue-specific and measurement-specific parameters, including the local magnetic field B0, and reduces artifacts like blurring, leading to improved diagnostic capabilities.

Implementation Method 1

To trigger nuclear spin resonances, radio-frequency excitation pulses (RF pulses) are irradiated into the examination object. The triggered nuclear spin resonances are measured as so-called k-space data

Methodology Applied
Scientific EffectNuclear spin resonance: Resonance

Implementation Method 2

For spatial encoding of the measurement data, rapidly switched magnetic gradient fields, which define the trajectories along which the detected MR signals are entered into k-space, are superimposed on the basic magnetic field

Methodology Applied
Scientific EffectMagnetic gradient encoding: Magnetic Field

Implementation Method 3

the examination object is positioned in a magnetic resonance scanner in a strong static, homogeneous basic magnetic field, also called the B0 field, with field strengths of 0.2 Tesla to 7 Tesla and more, so that nuclear spins in the object are oriented along the basic magnetic field

Methodology Applied
Scientific EffectMagnetic field orientation: Magnetic Field

Data Source

PatentUS10921406B2Magnetic resonance fingerprinting method and apparatus
Publication Date: 2021.02.16 SIEMENS HEALTHINEERS AG
  • US10921406B2 patent drawing
  • US10921406B2 patent drawing
  • US10921406B2 patent drawing

AI summary

In a magnetic resonance fingerprinting method and apparatus for improved determination of local parameter values of an examination object, in which at least two signal comparisons of acquired picture element time series are carried out with comparison signal curves for determination of parameter values. A further (subsequent) signal comparison takes into account results of a preceding signal comparison. This multi-stage determination of parameter values allows an increase of the spatial resolution and the precision with which the parameter values can be determined.