Radiofrequency ablation: Importance of background tissue electrical conductivity - An agar phantom and computer modeling study

Stephanie A. Solazzo, Zhengjun Liu, S. Melvyn Lobo, Muneeb Ahmed, Andrew U. Hines-Peralta, Robert E. Lenkinkski, S. Nahum Goldberg

Research output: Contribution to journalArticle

88 Citations (Scopus)

Abstract

PURPOSE: To determine whether radiofrequency (RF)-induced heating can be correlated with background electrical conductivity in a controlled experimental phantom environment mimicking different background tissue electrical conductivities and to determine the potential electrical and physical basis for such a correlation by using computer modeling. MATERIALS AND METHODS: The effect of background tissue electrical conductivity on RF-induced heating was studied in a controlled system of 80 two-compartment agar phantoms (with inner wells of 0.3%, 1.0%, or 36.0% NaCl) with background conductivity that varied from 0.6% to 5.0% NaCl. Mathematical modeling of the relationship between electrical conductivity and temperatures 2 cm from the electrode (T2cm) was performed: Next, computer simulation of RF heating by using two-dimensional finite-element analysis (ETherm) was performed with parameters selected to approximate the agar phantoms. Resultant heating, in terms of both the T 2cm and the distance of defined thermal isotherms from the electrode surface, was calculated and compared with the phantom data. Additionally, electrical and thermal profiles were determined, by using the computer modeling data and correlated by using linear regression analysis. RESULTS: For each inner compartment NaCl concentration, a negative exponential relationship was established between increased background NaCl concentration and the T 2cm (R2 = 0.64-0.78). Similar negative exponential relationships (r2 > 0.97%) were observed for the computer modeling. Correlation values (R2) between the computer and experimental data were 0.9, 0.9, and 0.55 for the 0.3%, 1.0%, and 36.0% inner NaCl concentrations, respectively. Plotting of the electrical field generated around the RF electrode identified the potential for a dramatic local change in electrical field distribution (ie, a second electrical peak ["E-peak"] ) occurring at the interface between the two compartments of varied electrical background conductivity. Linear correlations between the E-peak and heating at T2cm (R2 = 0.98-1.00) and the 50°C isotherm (R 2 = 0.99-1.00) were established. CONCLUSION: These results demonstrate the strong relationship between background tissue conductivity and RF heating and further explain electrical phenomena that occur in a two-compartment system.

Original languageEnglish (US)
Pages (from-to)495-502
Number of pages8
JournalRadiology
Volume236
Issue number2
DOIs
StatePublished - Aug 2005

Fingerprint

Electric Conductivity
Heating
Agar
Electrodes
Hot Temperature
Finite Element Analysis
Electromagnetic Phenomena
Computer Simulation
Linear Models
Regression Analysis
Temperature

ASJC Scopus subject areas

  • Radiological and Ultrasound Technology

Cite this

Solazzo, S. A., Liu, Z., Lobo, S. M., Ahmed, M., Hines-Peralta, A. U., Lenkinkski, R. E., & Goldberg, S. N. (2005). Radiofrequency ablation: Importance of background tissue electrical conductivity - An agar phantom and computer modeling study. Radiology, 236(2), 495-502. https://doi.org/10.1148/radiol.2362040965

Radiofrequency ablation : Importance of background tissue electrical conductivity - An agar phantom and computer modeling study. / Solazzo, Stephanie A.; Liu, Zhengjun; Lobo, S. Melvyn; Ahmed, Muneeb; Hines-Peralta, Andrew U.; Lenkinkski, Robert E.; Goldberg, S. Nahum.

In: Radiology, Vol. 236, No. 2, 08.2005, p. 495-502.

Research output: Contribution to journalArticle

Solazzo, SA, Liu, Z, Lobo, SM, Ahmed, M, Hines-Peralta, AU, Lenkinkski, RE & Goldberg, SN 2005, 'Radiofrequency ablation: Importance of background tissue electrical conductivity - An agar phantom and computer modeling study', Radiology, vol. 236, no. 2, pp. 495-502. https://doi.org/10.1148/radiol.2362040965
Solazzo, Stephanie A. ; Liu, Zhengjun ; Lobo, S. Melvyn ; Ahmed, Muneeb ; Hines-Peralta, Andrew U. ; Lenkinkski, Robert E. ; Goldberg, S. Nahum. / Radiofrequency ablation : Importance of background tissue electrical conductivity - An agar phantom and computer modeling study. In: Radiology. 2005 ; Vol. 236, No. 2. pp. 495-502.
@article{c3b6f9186e364e7485e863fc22c5a7b8,
title = "Radiofrequency ablation: Importance of background tissue electrical conductivity - An agar phantom and computer modeling study",
abstract = "PURPOSE: To determine whether radiofrequency (RF)-induced heating can be correlated with background electrical conductivity in a controlled experimental phantom environment mimicking different background tissue electrical conductivities and to determine the potential electrical and physical basis for such a correlation by using computer modeling. MATERIALS AND METHODS: The effect of background tissue electrical conductivity on RF-induced heating was studied in a controlled system of 80 two-compartment agar phantoms (with inner wells of 0.3{\%}, 1.0{\%}, or 36.0{\%} NaCl) with background conductivity that varied from 0.6{\%} to 5.0{\%} NaCl. Mathematical modeling of the relationship between electrical conductivity and temperatures 2 cm from the electrode (T2cm) was performed: Next, computer simulation of RF heating by using two-dimensional finite-element analysis (ETherm) was performed with parameters selected to approximate the agar phantoms. Resultant heating, in terms of both the T 2cm and the distance of defined thermal isotherms from the electrode surface, was calculated and compared with the phantom data. Additionally, electrical and thermal profiles were determined, by using the computer modeling data and correlated by using linear regression analysis. RESULTS: For each inner compartment NaCl concentration, a negative exponential relationship was established between increased background NaCl concentration and the T 2cm (R2 = 0.64-0.78). Similar negative exponential relationships (r2 > 0.97{\%}) were observed for the computer modeling. Correlation values (R2) between the computer and experimental data were 0.9, 0.9, and 0.55 for the 0.3{\%}, 1.0{\%}, and 36.0{\%} inner NaCl concentrations, respectively. Plotting of the electrical field generated around the RF electrode identified the potential for a dramatic local change in electrical field distribution (ie, a second electrical peak [{"}E-peak{"}] ) occurring at the interface between the two compartments of varied electrical background conductivity. Linear correlations between the E-peak and heating at T2cm (R2 = 0.98-1.00) and the 50°C isotherm (R 2 = 0.99-1.00) were established. CONCLUSION: These results demonstrate the strong relationship between background tissue conductivity and RF heating and further explain electrical phenomena that occur in a two-compartment system.",
author = "Solazzo, {Stephanie A.} and Zhengjun Liu and Lobo, {S. Melvyn} and Muneeb Ahmed and Hines-Peralta, {Andrew U.} and Lenkinkski, {Robert E.} and Goldberg, {S. Nahum}",
year = "2005",
month = "8",
doi = "10.1148/radiol.2362040965",
language = "English (US)",
volume = "236",
pages = "495--502",
journal = "Radiology",
issn = "0033-8419",
publisher = "Radiological Society of North America Inc.",
number = "2",

}

TY - JOUR

T1 - Radiofrequency ablation

T2 - Importance of background tissue electrical conductivity - An agar phantom and computer modeling study

AU - Solazzo, Stephanie A.

AU - Liu, Zhengjun

AU - Lobo, S. Melvyn

AU - Ahmed, Muneeb

AU - Hines-Peralta, Andrew U.

AU - Lenkinkski, Robert E.

AU - Goldberg, S. Nahum

PY - 2005/8

Y1 - 2005/8

N2 - PURPOSE: To determine whether radiofrequency (RF)-induced heating can be correlated with background electrical conductivity in a controlled experimental phantom environment mimicking different background tissue electrical conductivities and to determine the potential electrical and physical basis for such a correlation by using computer modeling. MATERIALS AND METHODS: The effect of background tissue electrical conductivity on RF-induced heating was studied in a controlled system of 80 two-compartment agar phantoms (with inner wells of 0.3%, 1.0%, or 36.0% NaCl) with background conductivity that varied from 0.6% to 5.0% NaCl. Mathematical modeling of the relationship between electrical conductivity and temperatures 2 cm from the electrode (T2cm) was performed: Next, computer simulation of RF heating by using two-dimensional finite-element analysis (ETherm) was performed with parameters selected to approximate the agar phantoms. Resultant heating, in terms of both the T 2cm and the distance of defined thermal isotherms from the electrode surface, was calculated and compared with the phantom data. Additionally, electrical and thermal profiles were determined, by using the computer modeling data and correlated by using linear regression analysis. RESULTS: For each inner compartment NaCl concentration, a negative exponential relationship was established between increased background NaCl concentration and the T 2cm (R2 = 0.64-0.78). Similar negative exponential relationships (r2 > 0.97%) were observed for the computer modeling. Correlation values (R2) between the computer and experimental data were 0.9, 0.9, and 0.55 for the 0.3%, 1.0%, and 36.0% inner NaCl concentrations, respectively. Plotting of the electrical field generated around the RF electrode identified the potential for a dramatic local change in electrical field distribution (ie, a second electrical peak ["E-peak"] ) occurring at the interface between the two compartments of varied electrical background conductivity. Linear correlations between the E-peak and heating at T2cm (R2 = 0.98-1.00) and the 50°C isotherm (R 2 = 0.99-1.00) were established. CONCLUSION: These results demonstrate the strong relationship between background tissue conductivity and RF heating and further explain electrical phenomena that occur in a two-compartment system.

AB - PURPOSE: To determine whether radiofrequency (RF)-induced heating can be correlated with background electrical conductivity in a controlled experimental phantom environment mimicking different background tissue electrical conductivities and to determine the potential electrical and physical basis for such a correlation by using computer modeling. MATERIALS AND METHODS: The effect of background tissue electrical conductivity on RF-induced heating was studied in a controlled system of 80 two-compartment agar phantoms (with inner wells of 0.3%, 1.0%, or 36.0% NaCl) with background conductivity that varied from 0.6% to 5.0% NaCl. Mathematical modeling of the relationship between electrical conductivity and temperatures 2 cm from the electrode (T2cm) was performed: Next, computer simulation of RF heating by using two-dimensional finite-element analysis (ETherm) was performed with parameters selected to approximate the agar phantoms. Resultant heating, in terms of both the T 2cm and the distance of defined thermal isotherms from the electrode surface, was calculated and compared with the phantom data. Additionally, electrical and thermal profiles were determined, by using the computer modeling data and correlated by using linear regression analysis. RESULTS: For each inner compartment NaCl concentration, a negative exponential relationship was established between increased background NaCl concentration and the T 2cm (R2 = 0.64-0.78). Similar negative exponential relationships (r2 > 0.97%) were observed for the computer modeling. Correlation values (R2) between the computer and experimental data were 0.9, 0.9, and 0.55 for the 0.3%, 1.0%, and 36.0% inner NaCl concentrations, respectively. Plotting of the electrical field generated around the RF electrode identified the potential for a dramatic local change in electrical field distribution (ie, a second electrical peak ["E-peak"] ) occurring at the interface between the two compartments of varied electrical background conductivity. Linear correlations between the E-peak and heating at T2cm (R2 = 0.98-1.00) and the 50°C isotherm (R 2 = 0.99-1.00) were established. CONCLUSION: These results demonstrate the strong relationship between background tissue conductivity and RF heating and further explain electrical phenomena that occur in a two-compartment system.

UR - http://www.scopus.com/inward/record.url?scp=22544465241&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=22544465241&partnerID=8YFLogxK

U2 - 10.1148/radiol.2362040965

DO - 10.1148/radiol.2362040965

M3 - Article

C2 - 16040906

AN - SCOPUS:22544465241

VL - 236

SP - 495

EP - 502

JO - Radiology

JF - Radiology

SN - 0033-8419

IS - 2

ER -