Non-invasive spatio-temporal temperature estimation using diagnostic ultrasound

A method for non-invasively estimating tissue temperatures using 2D diagnostic ultrasound imaging arrays is presented in this paper. It is based on a linear relationship between the apparent speckle pattern displacements and temperature, as seen on acquired A-lines when the sample is heated by external heating fields. The proportionality constant between speckle displacement and temperature is determined by the differential change in the speed of sound due to temperature and the linear coefficient of thermal expansion of the material. Accurate estimation of the displacements and proportionality constant translates into accurate, calibrated, high-resolution (2 mm spatial, sub-/spl deg/C) noninvasive 2D spatio-temporal sample temperature estimates. The mathematical background of this method and experimental results are shown.