Optimizing radiofrequency ablation parameters for perianal fistula treatment: A porcine model study

Figure 3 Representative histological section illustrating Image J-based quantification of ablation and granulation tissue. A: Hematoxylin and eosin -stained cross-section of an outer fistula-tract segment harvested after radiofrequency ablation ablation (120 °C/24 seconds), showing a centrally obliterated lumen surrounded by a concentric zone of thermal injury; B: The same section processed in Image J, with color overlays delineating tissue compartments used for morphometry: Residual lumen (black), carbonized/charred core (violet), coagulative necrosis (red), transition zone (orange) and residual granulation tissue (yellow).