Simultaneous estimation of blood flow rate and tissue temperature.
A new method for simultaneously estimating blood flow rate and tissue temperature under a RF hyperthermia treatment is presented. In this method the finite element method is used to solve the two-dimensional Laplace equation for a specific absorption rate (SAR) distribution and the two-dimensional bioheat transfer equation for a tissue temperature distribution from the SAR pattern over a cross-section of a patient-specific model input from computer tomography images. Blood flow rates used in the temperature distribution computation are determined from basal values given for respective types of tissues and tissue temperatures through an assumed function that is intended to represent the temperature dependence of the blood flow rate. The tissue temperature computation procedure is iterated until the estimated temperature at a given sampling point matches a measured value at that point. This iterative procedure allows one to simultaneously estimate blood flow rate and tissue temperature. This paper describes the numerical method along with results of rudimentary in vivo measurements made in a human brain, where blood flow rate was measured by the single photon emission computed tomography (SPECT) imaging technique and tissue temperature was measured by an invasive probe technique.
Kato
K
K
Department of Electrical Engineering, Nagaoka University of Technology, Japan.
Matsuda
J
J
Yamashita
T
T
Tanaka
R
R
D001783:Blood Flow Velocity; D001831:Body Temperature; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging / Q000502:physiology; D001932:Brain Neoplasms / Q000098:blood supply / Q000503:physiopathology / Q000628:therapy*; D003198:Computer Simulation; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods; D008433:Mathematics; D008954:Models, Biological; D008991:Monitoring, Physiologic / Q000379:methods; D014055:Tomography, Emission-Computed