The present invention is a method to register 3D image data with fluoroscopic images of the chest of a patient. The ribs and spine, which are visible in the fluoroscopic images, are analyzed and a rib signature or cost map is generated. The rib signature or cost map is matched to corresponding structures of the 3D image data of the patient. Registration is evaluated by computing a difference between the fluoroscopic image and a virtual fluoroscopic projected image of the 3D data. Related systems are also described.
