Real-time, tissue-adaptive photoacoustic thermometry for precision endoscopic thermal therapy

Abstract

Atherosclerosis is a major cause of cardiovascular diseases, and photothermal ablation offers a minimally invasive alternative but is limited by unreliable thermal monitoring. Conventional probes such as thermocouples and fiber-optic sensors are direct lesion-contact probes, providing only point or surface measurements with slow response and failing to capture spatial distributions. Meanwhile, current photoacoustic (PA) thermometry relies on bulky arrays and possesses inadequate resolution for small lesions, which is incompatible with catheter applications. Here, this work achieves real-time intravascular temperature monitoring through photoacoustic endoscopic thermometry with spatially adaptive weighting (PAET-SAW). Using a miniaturized single-element transducer with rotational pullback scanning for 3D acquisition, our PAET system enables dual-modality imaging with real-time feedback. Phantom and ex vivo validations demonstrate reliable thermometry at 20 Hz with ≤ 0.68°C error and a ∼2 s faster response than thermocouples. Simulated therapeutic experiments further confirm that PAET-SAW-guided monitoring reduces excessive thermal dose and suppresses overshoot, underscoring strong clinical potential for precision intravascular interventions.