Perfusion Imaging Using Material Decomposition for Tissue Variation

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Solution Overview

Problem

Conventional perfusion imaging methods, such as CT angiography, provide only morphological representations and fail to accurately quantify perfusion defects, particularly in tissues like lung parenchyma, due to variations in tissue morphology that can mimic or obscure perfusion changes.

Innovation Solution

A method and apparatus that generate perfusion image data sets by capturing and analyzing both contrast-enhanced and non-contrast-enhanced image data sets, using material decomposition to separate tissue and contrast medium distributions, and calculating a perfusion image data set that accounts for morphological variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If conventional CT angiography is used to detect thromboembolism, then morphological representation of vessels is obtained, but functional representation of perfusion defects is not provided

Engineering Contradiction:

Improvefunctional perfusion informationVSAvoidimaging method complexity

Core Design Contradiction:

Loss of informationVSDevice complexity

Solution Approach 1:

The imaging process is segmented into multiple energy acquisitions (first and second energy levels) to separately capture morphological and functional information. Material decomposition separates iodine contrast distribution from tissue density, enabling independent analysis of perfusion function and vascular morphology

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The X-ray energy parameter is changed between acquisitions (first and second energy levels) to enable spectral differentiation. This energy variation allows material decomposition to distinguish between iodine-enhanced regions and non-enhanced tissue, providing functional perfusion data

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If contrast medium concentration is used to represent perfusion, then functional information is obtained, but morphological variations cannot be differentiated

Engineering Contradiction:

Improveperfusion quantification accuracyVSAvoidtissue morphology information

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

Material decomposition extracts the iodine contrast medium distribution from the total attenuation signal, separating functional perfusion information from morphological tissue information. This extraction allows independent quantification of contrast concentration without contamination from tissue density variations

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The imaging system handles composite attenuation signals from multiple materials (iodine contrast, soft tissue, bone, air) simultaneously. By modeling the total attenuation as a sum of individual material contributions, the system can decompose and quantify each material's specific effect on the imaging signal

Inventive Principle:

Principle #40Composite materials

3Measurement precision

If single energy CT is used for imaging, then acquisition time is reduced, but material decomposition cannot be performed

Engineering Contradiction:

Improvematerial differentiation capabilityVSAvoidimaging acquisition efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The system performs periodic switching between first and second energy levels during acquisition. This periodic energy switching enables collection of spectral data necessary for material decomposition while maintaining continuous scanning motion, balancing spectral information gathering with acquisition efficiency

Inventive Principle:

Principle #19Periodic 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

Enables accurate quantification of perfusion by compensating for tissue density changes, providing a more reliable representation of perfusion defects and extending diagnostic capabilities beyond conventional methods.

Implementation Method 1

imaging methods are frequently based on the capture of X-rays, wherein so-called projection measurement data is generated

Methodology Applied

Scientific EffectX-ray: X-Ray

Implementation Method 2

During one or more rotations, the patient is irradiated with X-rays from the X-ray source, wherein image data sets in the form of projection measurement data or X-ray projection data are captured with the aid of the opposite X-ray detector

Methodology Applied

Scientific EffectX-ray attenuation: Absorption (EM radiation)

Implementation Method 3

Based on this, it is then, for example, possible to identify at least two materials via material decomposition

Methodology Applied

Scientific EffectMaterial decomposition:

Data Source

PatentUS12505536B2Method and apparatus for providing a perfusion image data set of a patient

Publication Date: 2025.12.23 SIEMENS HEALTHINEERS AG

AI summary

A first image data set and at least one second image data set are captured, and a contrast-enhanced image data set and a non-contrast image data set are determined based on the first and the at least one second image data set. The perfusion image data set is calculated based on a ratio of image values of the contrast-enhanced image data set and locally corresponding image values of the non-contrast image data set, and the perfusion image data set is provided via a second interface.