FIGURE 5. Difference (A) in maximum transverse field of view of CT (blue) and PET (orange) may lead to truncation artifacts in PET/CT images (B). CT images of large patients or patients with arms down appear truncated at sides, and derived attenuation maps appear to mask corrected emission activity. (B) CT, uncorrected, and corrected PET. (C) Truncated attenuation information may be recovered before CT-based attenuation correction.