Towards non-invasive imaging of surgical suture degradation with photoacoustic microscopy

The characterization of the degradation of surgical sutures (~500 μm diameter) up to ~9 mm in tissue phantoms and up to ~3 mm depth in euthanized mice, and its potential application in in vivo animals is demonstrated using a custom dark-field photo-acoustic microscope (PAM). By using a simple theoretical approach and modelling the characteristics of our ultrasound transducer, both theoretical and experimental observations are in good agreement. The implications of this work for industrial applications are discussed by comparing the measurements with an optical microscope and with a developed algorithm on tissue simulating phantoms and with ex vivo measurements using PAM.