A system for ultrasound interrogation of a lung including a memory, an electromagnetic (EM) board, an extended working channel (EWC), an EM sensor, a US transducer, and a processor. The memory stores a three dimensional (3D) model and pathway plan for navigating a luminal network. The EM board generates an EM field. The EWC is configured to navigate the luminal network toward a target following the pathway plan. The EM sensor extends distally from a distal end of the EWC and is configured to sense the EM field. The US transducer extends distally from a distal end of the EWC, generates US waves, and receives US waves reflected from the luminal network. The processor processes the sensed EM field to synchronize a location of the EM sensor in the 3D model, to process the reflected US waves to generate images, or to integrate the generated images with the 3D model.