A registration method whereby a sensor-based approach is used to establish initial registration and whereby upon the commencement of navigating an endoscope, image-based registration methods are used in order to more accurately maintain the registration between the endoscope location and previously-acquired images. A six-degree-of-freedom location sensor is placed on the probe in order to reduce the number of previously-acquired images that must be compared to a real-time image obtained from the endoscope.