Perfusion Image Quality Control via Motion Artifact Rejection

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Solution Overview

Problem

Magnetic resonance perfusion imaging is prone to motion artifacts due to patient movement and scanner instabilities, leading to inaccuracies in perfusion image acquisition, especially with low signal magnitude requiring multiple acquisitions and complex processing techniques.

Innovation Solution

Implementing a quality control analysis for initially processed perfusion images from tag and control image combinations to reject images with excessive motion artifacts, ensuring only high-quality images contribute to the final combined perfusion image, which can be done automatically or with user interaction, and can be conducted in real-time or offline.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple image acquisitions are performed to improve signal detection, then measurement precision improves, but loss of time increases due to prolonged acquisition duration

Engineering Contradiction:

Improveperfusion signal detection accuracyVSAvoidimage acquisition time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by performing motion correction registration on control images before they are used in perfusion calculation. This advance processing ensures that when multiple images are acquired over time, the baseline control image is already corrected for motion artifacts, allowing faster processing of the time series without compromising measurement precision

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If image series acquisition is extended to capture perfusion signal, then measurement precision improves, but reliability deteriorates due to patient movement artifacts

Engineering Contradiction:

Improveperfusion signal quantificationVSAvoidimage quality consistency

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent performs motion correction registration on control images in advance, before perfusion calculation. This preliminary correction establishes a stable, artifact-free baseline that improves the reliability of subsequent perfusion measurements, ensuring that control images do not contain motion artifacts that would compromise the accuracy of perfusion quantification

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using the registered control images to inform and guide the perfusion calculation process. The motion-corrected control images serve as a reference that feedback into the subtraction and averaging operations, allowing the system to compensate for motion artifacts and maintain consistent image quality across the time series

Inventive Principle:

Principle #23Feedback

3Reliability

If control image stability is improved to reduce artifacts, then reliability improves, but device complexity increases due to additional correction mechanisms

Engineering Contradiction:

Improvecontrol image stabilityVSAvoidimage processing system

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

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

Significantly improves the accuracy and quality of perfusion images by reducing motion artifacts and enhancing the reliability of perfusion-weighted or quantitative images, allowing for timely corrective actions during data acquisition.

Implementation Method 1

the examination subject is positioned in a strong, static, homogeneous basic magnetic field (field strengths of 0.2 Tesla to 7 Tesla and higher) in an MR apparatus so that the subject's nuclear spins become oriented along the basic magnetic field

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

Radio-frequency excitation pulses are radiated into the examination subject to excite nuclear magnetic resonances, the excited nuclear magnetic resonances being measured (detected

Methodology Applied

Scientific EffectNuclear magnetic resonance:

Implementation Method 3

For spatial coding of the measurement data, rapidly switched magnetic gradient fields are superimposed on the basic magnetic field

Methodology Applied

Scientific EffectMagnetic gradient field: Magnetic Field

Implementation Method 4

a contrast agent, which generates a signal that is detectable by magnetic resonance imaging, is injected into a subject, and the magnetic resonance data are acquired at a time when the contrast agent has optimally flowed into the region or anatomy of interest

Methodology Applied

Scientific EffectMagnetic resonance signal detection:

Data Source

PatentUS8203340B2Magnetic resonance method and apparatus for generating a perfusion image

Publication Date: 2012.06.19 SIEMENS MEDICAL SOLUTIONS USA INC

AI summary

In a magnetic resonance method and apparatus for generating perfusion images, a perfusion series of magnetic resonance perfusion images is acquired that includes tag images and at least one control image, that are grouped in pairs. From each pair an initially processed perfusion image is obtained, such as by subtraction. Each initially processed image is subjected to a quality control review by analysis with respect to at least one image quality criterion. Any initially processed image that does not satisfy the quality criterion is rejected. Only initially processed images that satisfy the quality criterion are combined to form a resultant magnetic resonance perfusion image. Artifacts in the resultant perfusion image are thereby reduced or avoided.