FIGURE 6. Example of failed software image fusion in patient with B-cell lymphoma. CT images were acquired during breath hold at deep inspiration with arms up. ¹⁸F-FDG PET images were acquired during free tidal breathing with arms down. Fusion images show major inaccuracies in upper thorax aperture and in region of diaphragm. (A) Transverse slice. (B) Coronal slice.