Non-Malignant, Yet Clinically Significant, FDG-Avid Abnormalities

During routine PET/CT evaluation of malignancy, we frequently encounter non-malignant, yet clinically significant, FDG-avid CT abnormalities that clearly require prompt reporting. 

Common examples include:

  • Acute diverticulitis: If associated pericolonic stranding is not present, be cautious that this is not a malignancy hidden in an area of diverticulosis. You may have to occasionally “hedge” in your report.
  • Colitis: Make sure the uptake is “long-segment” (not focal) or you may overlook a malignancy.
  • Cholecystitis: Do not miss a gallbladder carcinoma. Ultrasound correlation is required.
  • Pneumonia: Make sure this diagnosis fits the patient’s clinical presentation, or you will miss a malignancy.
  • Abscess: Make sure this diagnosis fits the patient’s clinical presentation.
  • Pancreatitis: Make sure this diagnosis fits the patient’s clinical presentation.