1. A system for ultrasound (US) interrogation comprising: a memory storing a three dimensional (3D) model of a luminal network and a pathway plan illustrating a pathway toward a target in the luminal network of the 3D model, wherein the 3D model is made of a plurality of two dimensional (2D) images, which are from computed tomography scanning, magnetic resonance imaging (MRI), fluoroscopic imaging, or X-ray imaging; an electromagnetic (EM) board configured to generate an EM field; a first catheter configured to navigate the luminal network toward a target by following the pathway plan; a second catheter configured to extend through the first catheter; an EM sensor configured to sense the EM field; a US transducer configured to generate US waves and receive US waves reflected from the luminal network, wherein the EM sensor is positioned at a distal portion of one of the first catheter and the second catheter, and the US transducer is positioned at a distal portion of the other one of the first catheter and the second catheter; a processor configured to process the sensed EM field to synchronize a location of the EM sensor in the 3D model, to process the reflected US waves to generate US images, and to integrate the generated US images with the 3D model at a location of the US transducer by replacing at least one of the plurality of 2D images of the 3D model at a location of the US transducer, which corresponds to a location of the EM sensor, with the generated US images to create an intra-procedural 3D model; and a display device configured to display the integrated 3D model and US images.