Heat equation inversion framework for average SAR calculation from magnetic resonance thermal imaging

Leeor Alon; Daniel K. Sodickson; Cem M. Deniz

doi:10.1002/bem.21996

Heat equation inversion framework for average SAR calculation from magnetic resonance thermal imaging

Leeor Alon, Daniel K. Sodickson, Cem M. Deniz

Biomedical Engineering

Research output: Contribution to journal › Article › peer-review

Abstract

Deposition of radiofrequency (RF) energy can be quantified via electric field or temperature change measurements. Magnetic resonance imaging has been used as a tool to measure three dimensional small temperature changes associated with RF radiation exposure. When duration of RF exposure is long, conversion from temperature change to specific absorption rate (SAR) is nontrivial due to prominent heat-diffusion and conduction effects. In this work, we demonstrated a method for calculation of SAR via an inversion of the heat equation including heat-diffusion and conduction effects. This method utilizes high-resolution three dimensional magnetic resonance temperature images and measured thermal properties of the phantom to achieve accurate calculation of SAR. Accuracy of the proposed method was analyzed with respect to operating frequency of a dipole antenna and parameters used in heat equation inversion. Bioelectromagnetics. 37:493-503, 2016.

Original language	English (US)
Pages (from-to)	493-503
Number of pages	11
Journal	Bioelectromagnetics
Volume	37
Issue number	7
DOIs	https://doi.org/10.1002/bem.21996
State	Published - Oct 1 2016

Keywords

MRI
dosimetry
exposure assessment
specific absorption rate
temperature mapping

ASJC Scopus subject areas

Biophysics
Physiology
Radiology Nuclear Medicine and imaging

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10.1002/bem.21996

Cite this

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title = "Heat equation inversion framework for average SAR calculation from magnetic resonance thermal imaging",

abstract = "Deposition of radiofrequency (RF) energy can be quantified via electric field or temperature change measurements. Magnetic resonance imaging has been used as a tool to measure three dimensional small temperature changes associated with RF radiation exposure. When duration of RF exposure is long, conversion from temperature change to specific absorption rate (SAR) is nontrivial due to prominent heat-diffusion and conduction effects. In this work, we demonstrated a method for calculation of SAR via an inversion of the heat equation including heat-diffusion and conduction effects. This method utilizes high-resolution three dimensional magnetic resonance temperature images and measured thermal properties of the phantom to achieve accurate calculation of SAR. Accuracy of the proposed method was analyzed with respect to operating frequency of a dipole antenna and parameters used in heat equation inversion. Bioelectromagnetics. 37:493-503, 2016.",

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T1 - Heat equation inversion framework for average SAR calculation from magnetic resonance thermal imaging

AU - Alon, Leeor

AU - Sodickson, Daniel K.

AU - Deniz, Cem M.

PY - 2016/10/1

Y1 - 2016/10/1

N2 - Deposition of radiofrequency (RF) energy can be quantified via electric field or temperature change measurements. Magnetic resonance imaging has been used as a tool to measure three dimensional small temperature changes associated with RF radiation exposure. When duration of RF exposure is long, conversion from temperature change to specific absorption rate (SAR) is nontrivial due to prominent heat-diffusion and conduction effects. In this work, we demonstrated a method for calculation of SAR via an inversion of the heat equation including heat-diffusion and conduction effects. This method utilizes high-resolution three dimensional magnetic resonance temperature images and measured thermal properties of the phantom to achieve accurate calculation of SAR. Accuracy of the proposed method was analyzed with respect to operating frequency of a dipole antenna and parameters used in heat equation inversion. Bioelectromagnetics. 37:493-503, 2016.

AB - Deposition of radiofrequency (RF) energy can be quantified via electric field or temperature change measurements. Magnetic resonance imaging has been used as a tool to measure three dimensional small temperature changes associated with RF radiation exposure. When duration of RF exposure is long, conversion from temperature change to specific absorption rate (SAR) is nontrivial due to prominent heat-diffusion and conduction effects. In this work, we demonstrated a method for calculation of SAR via an inversion of the heat equation including heat-diffusion and conduction effects. This method utilizes high-resolution three dimensional magnetic resonance temperature images and measured thermal properties of the phantom to achieve accurate calculation of SAR. Accuracy of the proposed method was analyzed with respect to operating frequency of a dipole antenna and parameters used in heat equation inversion. Bioelectromagnetics. 37:493-503, 2016.

KW - MRI

KW - dosimetry

KW - exposure assessment

KW - specific absorption rate

KW - temperature mapping

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Heat equation inversion framework for average SAR calculation from magnetic resonance thermal imaging

Abstract

Keywords

ASJC Scopus subject areas

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