1. Pakistan Institute of Engineering and Applied Science (PIEAS), Islamabad, Pakistan;2. Division of Biophysics and Bioimaging, Ontario Cancer Institute/University Health Network and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada;3. Sunnybrook Research Institute, Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada;4. Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
Abstract:
Radiofrequency (RF) ablation offers a potential treatment for cardiac arrhythmia, where properly titrated energy delivered at critical sites can destroy arrhythmogenic foci. The resulting ablation lesion typically consists of a core (coagulative necrosis) surrounded by a rim of mixed viable and non‐viable cells. The extent of the RF lesion is difficult to delineate with current imaging techniques. Here, we explore polarization signatures of ten ex‐vivo samples from untreated (n = 5) and RF ablated porcine hearts (n = 5), in backscattered geometry through Mueller matrix polarimetry. Significant differences (p < 0.01) in depolarization, ΔT, were observed between the healthy, RF ablated and rim regions. Linear retardance, δ, was significantly lower in the core and rim regions compared to healthy regions (p < 0.05). The results demonstrate a novel application of polarimetry, namely the characterization of RF ablation extent in myocardium, including the visualization of the important lesion rim region.
White light photo (top) of porcine myocardium tissue with radiofrequency ablation lesion and corresponding depolarization map (bottom). Depolarization is useful for visualizing the lesion core and rim.
