1. A system for mapping an area of interest in the body of a patient comprising: an intracardiac echocardiography system configured to generate a two dimensional echocardiogram image (ICE image) of a portion of the area of interest in the body of the patient; a visualization, navigation, or mapping system configured to: generate a geometric model of the area of interest in the body of the patient according to data respective of the area of interest of the body of the patient, wherein the data is different from the ICE image; acquire a first set of position signals from a first plurality of location sensors located on an ultrasound catheter; acquire a second set of position signals from a second location sensor; and determine the position and orientation of an ultrasound transducer located on the catheter and the position of the second location sensor within the geometric model; and an electronic control system (ECS) configured to acquire the ICE image, the geometric model, the position and orientation of the ultrasound transducer, and the position of the second location sensor, the ECS being further configured to generate a user interface comprising a rendering of the geometric model having a projection of the ICE image projecting from the ultrasound transducer, the user interface being further configured to receive user input identifying a fiducial point pair.