Temperature Mapping Using Ultrasound Digital Images

Abstract

Introduction: The success of hyperthermia depends on the accuracy of the temperature <br /> monitoring in the tumor and the surrounding normal tissue. In this study, the temperature changes <br /> were determined by computing the speckle displacement in the ultrasound digital images. Speckle <br /> tracking algorithm was used to compute the displacement. <br /> Materials and Methods: The experiment was performed on Tissue Mimicking (TM) phantoms. <br /> The imaging probe used was a commercial type linear array operating at 10 MHz. The speckle <br /> displacement along the axial direction was computed using Speckle Tracking method and the <br /> temperature changes were obtained from the displacement data. Additionally, the temperature <br /> changes during the heating were invasively measured by NTC thermistors. The results of the two <br /> methods were compared against each other. <br /> Results: There was a good agreement between the Ultrasonic temperature estimation and the <br /> measurements made by the thermistors. The maximum error and the standard deviation obtained <br /> were 0.53 and 0.2°C, respectively. <br /> Discussion and Conclusion: Speckle tracking algorithm is capable of extracting motion <br /> information from both the ultrasounic digital images and radiofrequency (RF) echo signals. The <br /> temperature changes can be obtained from the displacement data.