Measurement of blood flow using temperature decay: effect of thermal conduction

Within the framework of the bioheat equation, we studied the effect of conduction on the thermal washout curve for a model tissue configuration subjected to a thermal perturbation such as hyperthermia treatment. In particular, we studied the implications of the assumption made by many investigators to neglect the effect of thermal conduction while analyzing the temperature decay curve for measuring blood perfusion. The present analysis suggests that during the localized hyperthermia treatments, this assumption can lead to inaccurate values for the blood perfusion parameter. This is particularly so under non-steady state conditions when the temperature distribution is changing. In addition to the value of blood flow, the shape of the temperature decay curve depends on the temperature distribution at the start of temperature decay.