The present invention provides a method, including: introducing an instrument into a cavity of a subject； obtaining a first image from a first imaging modality； identifying on the first image from the first imaging modality at least one element, obtaining a second image from a second imaging modality； generating a compatible virtual image from the first image from the first imaging modality； mapping planning data on the compatible virtual image； coarse registering of the second image from the second imaging modality to the first image from the first imaging modality； identifying at least one element of the mapped planning data from the compatible virtual image； identifying a corresponding element on the second imaging modality； mapping the corresponding element on the second imaging modality； fine registering of the second image from the second imaging modality to the first image from the first imaging modality； generating a third image.
