In vivo photoacoustic tomography of porcine abdominal organs using Fabry-Pérot sensing integrated platform.

Abstract

Objective: To evaluate in vivo a fully integrated photoacoustic tomography imaging system based on Fabry-Pérot ultrasound sensing method applied on porcine abdominal organs. This approach could be used by surgeons during intraoperative clinical procedures.

Methods: The photoacoustic imaging system was fully integrated into a single structure, and the detection technology was based on a Fabry-Pérot interferometer. The detection probe connected to the imaging system was applied directly to the organs of a male "large white" Sus scrofa pig weighing 80 kg, either manually or using a stand, with or without a gel interface. All experiments were performed in compliance with EU Directive 2010/63/EU on animal experimentation (APAFiS #31507).

Results: All intraperitoneal and retroperitoneal organs were evaluated using photoacoustic imaging. The evaluation of both hollow and solid organs was successfully conducted with consistent three-dimensional image quality. We demonstrate the system's ability to image blood vessels with diameters ranging from several millimeters down to less than 100 µm. Macroscopic evaluation of the organs using photoacoustic tomography imaging did not reveal any damage or burns caused by the excitation laser.

Conclusion: To our knowledge, this is the first reported imaging session of abdominal organs in an in vivo porcine model, performed using a photoacoustic tomography system with Fabry-Pérot interferometer detection. We present a high-resolution photoacoustic tomography system that is closer to routine clinical translation, thanks to a fully integrated system.

Relevance statement: Photoacoustic evaluation of organs using a fully integrated system could become a valuable tool for surgical teams for intraprocedural assessment of vascularization.

Key points: Photoacoustic imaging visualizes blood vessels without contrast agents or ionizing radiation. Photoacoustic imaging systems detect blood vessels ranging from millimeters to 100 µm. Fully integrated photoacoustic imaging systems are autonomously operable by surgical teams.