The PULSE Lab received the 2nd phase of Dr. Bell’s NIH K99/R00 award to support our project entitled “Coherence-Based Photoacoustic Image Guidance of Transsphenoidal Surgeries”. This work is motivated by the clinical challenges surrounding the removal of pituitary tumors using the minimally invasive endonasal transsphenoidal approach, which incurs the deadly risk of causing injury to the internal carotid arteries. We propose to eliminate this risk by developing a sophisticated photoacoustic imaging system that visualizes blood vessels located behind bone during the surgical operation. This photoacoustic imaging system will be equipped with our novel coherence-based beamformers and our specialized light delivery systems.