Dynamic Registration-Based Photoacoustic Endoscopic Temperature Imaging for Precision Interventional Thermal Therapy and Monitoring

Atherosclerosis is a major cause of cardiovascular disease. Photothermal ablation provides a minimally invasive therapeutic approach but remains constrained by the lack of reliable temperature monitoring. Conventional thermometry provides only single-point readings and is easily affected by contact and flow, limiting spatial accuracy. Although array-based photoacoustic thermometry allows non-contact detection, it remains bulky and unsuitable for catheter integration. This study realizes real-time intravascular temperature imaging and monitoring through dynamic registration-corrected photoacoustic endoscopy (PETI-DRC). The system employs a miniaturized dual-modality catheter achieving photoacoustic/ultrasound imaging and angularly registered temperature mapping compatible with clinical interventions. Experiments on phantoms and ex vivo rabbit aortas quantitatively verified frame registration accuracy and temperature estimation reliability through comparison with thermocouple references and microscopic validation. Results show improved inter-frame consistency (average SSIM = 0.9684) and high temperature accuracy (RMSE $= 0.65~^{\circ }$ C), enabling stable reconstruction of angularly registered temperature images and reliable tracking of thermal dynamics for real-time temperature monitoring. This method provides accurate thermal feedback for safer and more effective photothermal therapy and offers a promising direction for future intravascular interventions.