MR-PET Detector Cassette Heating Prediction from MRI Eddy Currents

Solution Overview

Problem

Magnetic resonance tomography sequences can cause high temperatures in components within the examination tunnel, potentially damaging or impairing the functionality of PET detector cassettes in combined MR-PET systems.

Innovation Solution

A method using a temperature model to estimate the increase in temperature due to eddy currents induced by gradient waveforms, allowing for the calculation and prediction of temperature rises in components, and providing measures to prevent excessive heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If magnetic resonance tomography sequences are applied to achieve imaging, then diagnostic capability is improved, but temperature increases in components occur due to eddy currents

Engineering Contradiction:

Improveimaging capabilityVSAvoidcomponent temperature

Core Design Contradiction:

Measurement precisionVSTemperature

Solution Approach 1:

The patent applies preliminary action by calculating the temperature increase in detector cassettes before executing the magnetic resonance tomography sequence. The control device computes the expected temperature rise based on the gradient waveform and component properties, and only allows sequence execution if the temperature remains below a threshold value, thus preventing thermal damage before it occurs

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using a temperature model that calculates the thermal impact of gradient waveforms on detector cassettes. The control device receives information about the detector cassette position and gradient waveform, computes the resulting temperature increase, and uses this feedback to determine whether to permit or prevent the magnetic resonance sequence execution

Inventive Principle:

Principle #23Feedback

2Measurement precision

If gradient waveforms are applied to generate magnetic fields for imaging, then spatial localization is improved, but eddy currents are induced causing harmful heating

Engineering Contradiction:

Improvespatial localization precisionVSAvoideddy current heating

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by calculating the temperature increase in detector cassettes before executing the magnetic resonance tomography sequence. The control device computes the expected temperature rise based on the gradient waveform and component properties, and only allows sequence execution if the temperature remains below a threshold value, thus preventing thermal damage before it occurs

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using a temperature model that calculates the thermal impact of gradient waveforms on detector cassettes. The control device receives information about the detector cassette position and gradient waveform, computes the resulting temperature increase, and uses this feedback to determine whether to permit or prevent the magnetic resonance sequence execution

Inventive Principle:

Principle #23Feedback

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 the identification and prevention of potentially damaging temperature increases in components, ensuring the safety and functionality of PET detector cassettes by adjusting or preventing harmful magnetic resonance tomography sequences.

Implementation Method 1

the temperature model is designed so that it carries out the calculation of the increase in temperature on the basis of an estimation of eddy currents induced by the at least one gradient waveform in the at least one component

Methodology Applied

Scientific EffectEddy currents: Eddy Currents

Implementation Method 2

estimation of eddy currents induced by the at least one gradient waveform

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

Through the large magnetic fields, in particular also the large changes in magnetic fields, which arise in an examination tunnel of magnetic resonance tomography systems

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentUS12386001B2Estimating an influence of a magnetic resonance tomography sequence on at least one component in or on an examination tunnel and protection of the component

Publication Date: 2025.08.12 SIEMENS HEALTHINEERS AG

AI summary

A computer-implemented method for estimating an influence of a magnetic resonance tomography sequence on at least one component in or on an examination tunnel of a magnetic resonance tomography system, wherein the method comprises inputting at least one gradient waveform of the magnetic resonance tomography sequence into a temperature model; calculating an increase in temperature caused by an application of the magnetic resonance tomography sequence in the at least one component using the temperature model, the temperature model configured to calculate the increase in temperature based on an estimation of eddy currents induced by the at least one gradient waveform in the at least one component; and outputting at least one of the calculated increase in temperature or a temperature achieved by the increase in temperature.