A comparative infrared thermography framework for analyzing magnetic nanoparticle-mediated heating in agar phantom model

Infrared thermography is a valuable tool for characterizing spatiotemporal heat distributions in tissue-mimicking media, which is crucial for the successful implementation and optimization of in vivo magnetic nanoparticle–mediated heating (nanoheating) in magnetic hyperthermia applications. This study presents a comparative multiscale thermographic framework to investigate heat generation, transfer, and distribution from magnetite (Fe3O4) nanoparticles subjected to AC magnetic fields in a simulated biological medium. Agar cylindrical phantoms were designed to mimic a homogeneous medium, and an aqueous suspension of magnetite (Fe3O4) nanoparticles was placed in a centrally located cavity. The cylinders were then covered with agar discs of varying thicknesses to simulate different heat-source depths and evaluate thermal attenuation and its impact on surface detectability. Punctual, linear, and spatial image-processing strategies were systematically compared to determine the type of information each one provides for interpreting the heating process, particularly in terms of heating dynamics, depth-related attenuation, and practical detectability limits. This comparative framework supports a more structured interpretation of controlled phantom-based magnetic hyperthermia (MHT) experiments by evaluating the complementary value of punctual, linear, and spatial thermographic processing strategies within a low-cost and non-invasive infrared camera.