Label-free tumor detection with active infrared thermal laparoscopic system in a mouse tumor model

摘要

While passive thermal imaging of temperature difference between tumor and neighboring tissue provides limited contrast, active infrared thermal imaging with external heating or cooling may provide a unique contrast mechanism due to distinct thermal responses of tumor from neighboring tissue. We previously developed an active thermo-modulation imaging method with physiologically relevant parameters including the rate of temperature change and thermal relaxation time for tumor detection. Different from conventional passive thermal imaging, active thermo-modulation provides a contrast factor which is the average rate temperature change between tumor and neighboring tissue. With the tumors, the average rate of temperature change was higher than that of neighboring tissue with heating and cooling modulation. For endoscopic infrared thermal imaging, anti-reflection germanium lenses are tested as they have higher reflected indices and transmittance at mid-infrared spectrum. Combined with thermo-modulation, the newly developed infrared endoscopy can advance label-free non-invasive endoscopic screening.