Affiliation:
1. Ultrasound and Optical Imaging Laboratory, Department of Bioengineering The University of Texas at Arlington Arlington Texas USA
2. Joint Biomedical Engineering Program The University of Texas at Arlington and The University of Texas Southwestern Medical Center Dallas Texas USA
Abstract
AbstractTemperature measurements in biological tissues play a crucial role in studying metabolic activities. In this study, we introduce a noninvasive thermometry technique based on two‐color ultrasound‐switchable fluorescence (USF). This innovative method allows for a local temperature mapping within a microtube filled with temperature‐sensitive liposomes as nano imaging agents. By measuring the temperature‐dependent fluorescence emission of the liposomes using a spectrometer, we identify four characteristic temperatures. The local background temperature can be estimated by analyzing the corresponding appearance time of these four characteristic temperatures in the dynamic USF signals captured by a camera‐based USF system with two detection channels. Simultaneous measurements with an infrared (IR) camera showed a 0.38°C ± 0.27°C difference between USF thermometry and IR thermography in a physiological temperature range of 36.48°C–40.14°C. This shows that the two‐color USF thermometry technique is a reliable, noninvasive tool with excellent spatial and thermal resolution.
Funder
National Institute of Biomedical Imaging and Bioengineering