Figure 1. ¹⁸FDG-PET documentation of CT-occult primary pancreatic ductal adenocarcinoma. The patient had obstructive jaundice and distal common bile duct stricture on endoscopic retrograde cholangiopancreatography. Helical CT failed to demonstrate a low-attenuation mass in the pancreatic head. ¹⁸FDG-PET demonstrated a focus of increased uptake in the region of the pancreatic head (SUR = 4.3). Pancreaticoduodenectomy was performed with histologic confirmation of a 1.2-cm pancreatic ductal adenocarcinoma. (A) Transverse reconstruction of ¹⁸FDG-PET demonstrating pancreatic head lesion (arrow). (B) Coronal view. (C) Sagittal view. (D) CT scan at the level of the tumor, demonstrating failure to detect the primary lesion.