Systems and methods for imaging a body cavity and for guiding a treatment element within a body cavity are provided. A system may include an imaging subsystem having an imaging device and an image processor that gather image data for the body cavity. A mapping subsystem may be provided, including a mapping device and a map processor, to identify target sites within the body cavity, and provide location data for the sites. The system may also include a location processor coupled to a location element on a treatment device to track the location of the location element. The location of a treatment element is determined by reference to the location element. A treatment subsystem including a treatment device having a treatment element and a treatment delivery source may also be provided. A registration subsystem receives and registers data from the other subsystems, and displays the data.