Sorry, you need to enable JavaScript to visit this website.

Temperature dependence of thermal properties of ex vivo liver tissue up to ablative temperatures

TitleTemperature dependence of thermal properties of ex vivo liver tissue up to ablative temperatures
Publication TypeArticolo su Rivista peer-reviewed
Year of Publication2019
AuthorsLopresto, V., Argentieri A., Pinto Rosanna, and Cavagnaro M.
JournalPhysics in Medicine and Biology
Volume64
ISSN00319155
KeywordsAblation, Ex-vivo, Mammals, Non-linear regression analysis, Physiological models, Physiological temperature, Regression analysis, Specific heat, Temperature dependence, Temperature distribution, Temperature-dependent changes, Thermal ablation, Thermal conductivity, Tissue, treatment planning, Volumetric heat capacity
Abstract

Thermal properties of ex vivo bovine liver were measured as a function of temperature, by heating tissue samples in a temperature-controlled oil bath over a temperature range from about 21 °C to about 113 °C. Results evidenced temperature-dependent non-linear changes of the thermal properties, with the temperature of 100 °C representing a break point: the thermal properties increased with temperature up to 99 °C and then decreased above 100 °C. The rate of increase appeared dramatic between 90 °C and 99 °C, owing to the onset of vaporisation of water contained in the tissue. In particular, at 99 °C, the thermal conductivity reported an increase of about four times with respect to the value measured at 90 °C, whilst about a two-fold increase was reported for both the volumetric heat capacity and the thermal diffusivity. Temperatures higher than 100 °C were reached only after complete vaporisation of water contained in the tissue, resulting in about 70% loss of weight from the tissue. An overall decrease of about 71% and 63% was reported for the thermal conductivity and volumetric heat capacity, respectively, in the temperature range 101 °C-113 °C. A decrease of about 25% was reported in the measured values of the thermal diffusivity in the temperature range 101 °C-108 °C, whilst a slight increase of measured values, not statistically significant, was observed in the temperature range 108 °C-113 °C. The temperature dependent changes of the thermal parameters were modelled with non-linear regression analysis to calculate the best-fit curves interpolating measured data. The proposed regression models could be used to numerically assess the changes in the thermal properties of biological tissues at supra-physiological temperatures relevant in thermal ablation procedures, as well as their effect on the prediction of the ablation zone dimensions in computational models for treatment planning. © 2019 Institute of Physics and Engineering in Medicine.

Notes

cited By 0

URLhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85066920728&doi=10.1088%2f1361-6560%2fab1663&partnerID=40&md5=82b65b44ed575aa2a6d80b977cd75982
DOI10.1088/1361-6560/ab1663
Citation KeyLopresto2019