A method of medical image processing for images of body structures, comprising: receiving anatomical data to reconstruct an anatomical image of a region of a body of a patient, said region comprises a portion of at least one internal body part which borders or is spaced apart from a target tissue; receiving functional data from a functional imaging modality which images at least said portion of the region of the body of the patient; processing said anatomical image to generate at least one image mask corresponding to the zone outside of the wall of said at least one internal body part; correlating the at least one generated image mask with the functional data for guiding a reconstruction of a functional image depicting said target tissue; and providing the reconstructed functional image.