Non-invasive Cerebrovascular Reserve Measurement via PET

Solution Overview

Problem

Current methods for measuring cerebrovascular reserve (CVR) and cerebral blood flow (CBF) using 15O-water positron emission tomography (PET) require invasive arterial cannulation and sampling, which is risky, painful, and limits clinical application.

Innovation Solution

A non-invasive method involving two 15O-water PET scans, with a fixed amount of radioactivity administered at a controlled injection rate, allowing for the measurement of CVR and CBF without the need for arterial cannulation. This method uses a controlled automated power injector and a tracer kinetic model that describes vasodilation data as a function of baseline data and CVR.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If invasive arterial cannulation and sampling are used to obtain quantitative CBF and CVR values, then measurement precision is improved, but patient safety and ease of operation deteriorate

Engineering Contradiction:

Improvequantitative CBF and CVR measurementVSAvoidrisk and pain from arterial cannulation

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent uses an image-derived input function (IDIF) as an intermediary to replace the need for direct arterial sampling. The IDIF is obtained from PET images of the carotid arteries, serving as a non-invasive surrogate for the arterial input function required in traditional quantitative CBF and CVR measurements. This intermediary approach maintains measurement accuracy while eliminating the harmful effects of arterial cannulation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical invasive system of arterial cannulation and blood sampling with a non-invasive imaging-based system. Instead of physically accessing arteries to obtain blood samples for input function measurement, the system uses PET imaging to non-invasively derive the arterial input function from carotid artery images, thereby substituting a mechanical invasive procedure with an imaging-based non-invasive approach.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If invasive arterial cannulation is performed to enable quantitative measurement, then measurement precision is improved, but ease of operation and clinical applicability worsen

Engineering Contradiction:

Improvequantitative CBF and CVR measurementVSAvoidclinical applicability

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent uses an image-derived input function (IDIF) as an intermediary to replace the need for direct arterial sampling. The IDIF is obtained from PET images of the carotid arteries, serving as a non-invasive surrogate for the arterial input function required in traditional quantitative CBF and CVR measurements. This intermediary approach maintains measurement accuracy while eliminating the harmful effects of arterial cannulation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical invasive system of arterial cannulation and blood sampling with a non-invasive imaging-based system. Instead of physically accessing arteries to obtain blood samples for input function measurement, the system uses PET imaging to non-invasively derive the arterial input function from carotid artery images, thereby substituting a mechanical invasive procedure with an imaging-based non-invasive approach.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If arterial cannulation and sampling are used for quantitative measurement, then measurement precision is improved, but device complexity and procedural risk increase

Engineering Contradiction:

Improvequantitative CBF and CVR measurementVSAvoidprocedural complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses an image-derived input function (IDIF) as an intermediary to replace the need for direct arterial sampling. The IDIF is obtained from PET images of the carotid arteries, serving as a non-invasive surrogate for the arterial input function required in traditional quantitative CBF and CVR measurements. This intermediary approach maintains measurement accuracy while eliminating the harmful effects of arterial cannulation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical invasive system of arterial cannulation and blood sampling with a non-invasive imaging-based system. Instead of physically accessing arteries to obtain blood samples for input function measurement, the system uses PET imaging to non-invasively derive the arterial input function from carotid artery images, thereby substituting a mechanical invasive procedure with an imaging-based non-invasive approach.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 safe, non-invasive, and quantitative measurement of CVR and CBF, overcoming the limitations of invasive methods and allowing for widespread clinical use.

Implementation Method 1

a first IV bolus 15O-water tracer at a first time point and to administer a second IV bolus 15O-water tracer at a second time point

Methodology Applied

Scientific EffectRadioactive tracing: Radioactive Tracing

Data Source

PatentEP4552577A1Estimation of cerebrovascular reserve

Publication Date: 2025.05.14 MEDTRACE AS

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AI summary

The present invention relates to a method for non-invasive quantitative measurement of cerebrovascular reserve (CVR) and cerebral blood flow (CBF) with 15O -water positron emission tomography (PET).