Methods and systems for processing and/or superimposing a medical image of
an anatomical body (e.g., a heart) with graphical information are
provided. Reference elements and/or reference catheter are placed in
contact with the anatomical body. A physical structure within a
navigational coordinate system is located using the reference elements
and/or reference catheter. An image reference within an image coordinate
corresponding to the physical structure is located. Location of the image
reference can be accomplished, e.g., by displaying the medical image and
electronically marking the displayed image reference, or by automatically
locating image data corresponding to the image reference. The
navigational and image coordinate systems are then registered based on
the location of the physical structure within the navigational coordinate
system and the location of the image reference within the image
coordinate system, which allows graphical information to be accurately
merged with the medical image data.