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Transient finite element analysis of thermal methods used to estimate SAR and blood flow in homogeneously and nonhomogeneously perfused tumour models.

Publication ,  Journal Article
Wong, TZ; Mechling, JA; Jones, EL; Strohbehn, JW
Published in: Int J Hyperthermia
1988

A two-dimensional time-dependent finite element model was developed to evaluate thermal techniques for estimating blood flow and specific absorption rate (SAR). In these computer simulations, homogeneously and nonhomogeneously perfused tumour models were heated by a 915 MHz interstitial microwave antenna array. Representative blood flow values were assigned within the tumour, and the applied SAR distribution was based on a previously developed antenna theory. SAR values were estimated from the power-on transient temperatures, and blood flow values were estimated from thermal clearance data after power was discontinued. These estimated parameters were then compared to the known 'true' blood flow and SAR values throughout the treatment region. SAR values could be predicted with reasonable accuracy throughout most of the heated region independent of local blood flow. For a homogeneous model, thermal clearance was found to yield reasonably accurate blood flow estimates at high perfusion rates and less accurate estimates at lower perfusion rates. However, for the inhomogeneous model, the blood perfusion estimates were generally poor, and an average blood flow value for the tumour was obtained with little ability to resolve the differences in perfusion between regions. Using temperatures observed early in the cool-down curve resulted in improved spatial resolution, but increased the contribution of thermal conduction to the blood flow estimates. A single time-constant exponential thermal decay curve was found to be a necessary but not sufficient condition for reliable blood flow estimates using this technique.

Duke Scholars

Published In

Int J Hyperthermia

DOI

ISSN

0265-6736

Publication Date

1988

Volume

4

Issue

6

Start / End Page

571 / 592

Location

England

Related Subject Headings

  • Temperature
  • Perfusion
  • Oncology & Carcinogenesis
  • Neoplasms
  • Models, Biological
  • Mathematics
  • Hyperthermia, Induced
  • Computer Simulation
  • Absorption
  • 1103 Clinical Sciences
 

Citation

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Wong, T. Z., Mechling, J. A., Jones, E. L., & Strohbehn, J. W. (1988). Transient finite element analysis of thermal methods used to estimate SAR and blood flow in homogeneously and nonhomogeneously perfused tumour models. Int J Hyperthermia, 4(6), 571–592. https://doi.org/10.3109/02656738809012398
Wong, T. Z., J. A. Mechling, E. L. Jones, and J. W. Strohbehn. “Transient finite element analysis of thermal methods used to estimate SAR and blood flow in homogeneously and nonhomogeneously perfused tumour models.Int J Hyperthermia 4, no. 6 (1988): 571–92. https://doi.org/10.3109/02656738809012398.
Wong, T. Z., et al. “Transient finite element analysis of thermal methods used to estimate SAR and blood flow in homogeneously and nonhomogeneously perfused tumour models.Int J Hyperthermia, vol. 4, no. 6, 1988, pp. 571–92. Pubmed, doi:10.3109/02656738809012398.
Journal cover image

Published In

Int J Hyperthermia

DOI

ISSN

0265-6736

Publication Date

1988

Volume

4

Issue

6

Start / End Page

571 / 592

Location

England

Related Subject Headings

  • Temperature
  • Perfusion
  • Oncology & Carcinogenesis
  • Neoplasms
  • Models, Biological
  • Mathematics
  • Hyperthermia, Induced
  • Computer Simulation
  • Absorption
  • 1103 Clinical Sciences