Ultrasound imaging in open surgery, such as hepatobiliary-pancreatic surgery, allows the surgeon to visualize complex anatomical variations, assisting with tumor location and an understanding of its interaction with the surrounding vascularization. 

Probes for open surgery include the finger-grip (or Makuuchi) probe and the linear T-shaped probe. 

The finger-grip probe acts as an extension of the surgeon’s finger allowing palpation while scanning, and access to small operating fields. 
The T-shaped probe, on the other hand, offers a wider field of view over a large area, making it useful for visualizing anatomical structures and blood flow.