The dynamic response of brain temperature to localized heating

Area of Science:

• Physiology
• Biophysics
• Mathematical Modeling

Background:

• Mathematical models for heat transport in perfused tissues exist but lack validation under dynamic temperature conditions.
• Understanding heat transfer in brain tissue is crucial for various neurological applications.

Purpose of the Study:

• To test and validate mathematical models of heat transport in perfused brain tissue under time-varying temperatures.
• To assess the accuracy of a specific heat transport model in predicting brain temperature responses.

Main Methods:

• Experimental measurements of baboon brain temperature responses to thermode temperature changes.
• Comparison of experimental data with numerical solutions of a heat transport equation.
• Parameter estimation for thermal diffusivity (k) and blood flow (ø).

Main Results:

• Good agreement was found between experimental and theoretical temperature curves.
• Model predictions were robust to physiological variations in k and ø and minor geometric errors.
• Inaccuracies in boundary conditions or scar tissue representation significantly impacted blood flow (ø) estimations.

Conclusions:

• The proposed mathematical model effectively describes thermal gradients around a thermode in brain tissue.
• Caution is advised when using this model for quantitative blood flow assessment due to sensitivity to boundary conditions and tissue properties.