New applications of planar image fusion in clinical nuclear medicine and radiology.

Fusion of multiple modalities has become an integral part of modern imaging methodology, especially in nuclear medicine where PET and SPECT scanning are frequently paired with computed tomography (CT). We have extended image fusion from the tomographic realm to planar imaging in 2 specific applications. In the first, we combine planar scintigraphic images with photographic images of the body part of interest, using a predetermined transformation of images between the frames of reference. This technique is especially helpful in "hot spot" imaging applications where minimal background activity makes it difficult to locate abnormalities in an anatomic context. The technique has been demonstrated to be accurate, and results in increased reader confidence. We have also begun fusing orthopedic radiographs with photographic images of the extremities, using fiducial markers within each image set to perform an affine transformation unique for the particular image set. Preliminary results indicate that this method is accurate, and clinical evaluation is underway.