Temperature Mapping Using Ultrasound Digital Images

Abstract

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