Annular illumination photoacoustic probe for needle guidance in medical interventions

During percutaneous medical interventions, accurate needle placement and advancing to the target of interest is required to avoid complications and to improve clinical outcomes. Therefore, we present a novel photoacoustic (PA) imaging-based approach as a complement to conventional ultrasound (US) imaging for visualization and guidance of interventional needles. To overcome the limitations associated with light penetration with the conventional extracorporeal illumination, we propose an interstitial light delivery to the target of interest by use of a custom-made annular illumination probe (AIP). This probe accommodates an interventional needle (14 gauge) within its lumen, allowing to advance both tools and acquire real-time PAUS images simultaneously. The light is delivered utilizing 72 multimode optical fibers arranged around the circumference of the hollow center of the AIP. Preliminary results show that PA images obtained with the AIP provide with good complementary contrast to the US imaging for visualization of the interventional needles and its guidance to an absorbing target within chicken breast tissue.