Model of local temperature changes in brain upon functional activation.
Experimental results for changes in brain temperature during functional activation show large variations. It is, therefore, desirable to develop a careful numerical model for such changes. Here, a three-dimensional model of temperature in the human head using the bioheat equation, which includes effects of metabolism, perfusion, and thermal conduction, is employed to examine potential temperature changes due to functional activation in brain. It is found that, depending on location in brain and corresponding baseline temperature relative to blood temperature, temperature may increase or decrease on activation and concomitant increases in perfusion and rate of metabolism. Changes in perfusion are generally seen to have a greater effect on temperature than are changes in metabolism, and hence active brain is predicted to approach blood temperature from its initial temperature. All calculated changes in temperature for reasonable physiological parameters have magnitudes <0.12 degrees C and are well within the range reported in recent experimental studies involving human subjects.
Collins
Christopher M
CM
Center for NMR Research, Dept. of Radiology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA. cmcollins@psu.edu
Smith
Michael B
MB
Turner
Robert
R
D001831:Body Temperature / Q000502:physiology*; D001921:Brain / Q000098:blood supply* / Q000378:metabolism*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003198:Computer Simulation; D006801:Humans; D008297:Male; D008954:Models, Biological; D053443:Visible Human Projects