Click on image to view larger version.
FIGURE 2. Attenuation-corrected PET image (A), PET/CT fusion image (B), CT image (C), and PET image uncorrected for attenuation (D) of 34-y-old man with hepatic metastases from colorectal cancer. Artifact caused by contrast agent leads to error in CT-based attenuation correction of PET images and simulates focal tracer uptake. Without knowledge of fusion images, interpreter is likely to misinterpret finding as mediastinal lymph node metastasis. When PET images are uncorrected for attenuation, artifact is not expressed (D).
