Minimally invasive surgery offers significant benefits
over open surgery in terms of patient recovery, complication
rates, and cost. Accurate visualisation is key for successful interventions; however, no single imaging modality offers sufficient
resolution, penetration, and soft-tissue contrast to adequately
monitor interventional treatment. Consequently, multimodal interventional imaging is intensively investigated. All-optical ultrasound (AOUS) imaging is an emerging modality where light is
used to both generate and detect ultrasound. Using fibre-optics,
highly miniaturised imaging probes can be fabricated that yield
high-quality pulse-echo images and are readily integrated into
minimally invasive interventional instruments. In this work, we
present the integration of a miniature (diameter: 800 µm), highly
directional AOUS imaging probe into a commercially available
white light urethroscope, and demonstrate the first real-time, 3D
multimodal imaging combining AOUS and white light endoscopy.
Through the addition of an electromagnetic tracker, the position
and pose of the instrument could be continuously recorded.
This facilitated accurate real-time registration of the imaging
modalities, as well as freehand operation of the instrument. In addition, the freehand imaging paradigm allowed for “piece-wise”
scanning where the instrument was retracted and repositioned
without recalibration. The presented imaging probe and system
could significantly improve the quality of image guidance during
interventional surgery
