title: Focal F-18 fluoro-deoxy-glucose accumulation in the lung parenchyma in the absence of CT abnormality in PET/CT.
abstract: OBJECTIVE
  To demonstrate 3 cases of artifactual focal F-18 fluoro-deoxy-glucose accumulation in the lung parenchyma in the absence of any computed tomographic (CT) abnormality.
  
  
  METHODS
  Three patients were examined: a 30-year-old man who had a positron emission tomography (PET)/computed tomography for restaging a biopsy-proven recurrence of head and neck cancer, a 68-year-old woman who was referred for initial staging of esophageal carcinoma, and a 57-year-old man who had a PET/computed tomography for initial staging of melanoma. In each case, there was intense focal activity in the lung parenchyma with no corresponding CT abnormality. Each patient was further evaluated with a repeat PET scan in days 1 and 3 in the first 2 cases and with a delayed repeat acquisition in the third case. Patients were followed for 24, 10, and 1 month, respectively.
  
  
  RESULTS
  In the first 2 cases, the abnormal focal activity in the lungs had resolved in the repeat study. In the third case, the focus of increased activity in the lung had moved more peripherally in the delayed acquisition. Clinical follow-up was negative for disease in the corresponding pulmonary parenchymal sites.
  
  
  CONCLUSIONS
  The finding of significant focal accumulation of fluoro-deoxy-glucose in the lung parenchyma in the absence of corresponding CT abnormality was artifactual. This was likely due to injection technique and the creation of particulate embolus. Positron emission tomography/Computed tomographic readers should be aware of this type of artifact to avoid misinterpretation.
authors: Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, MN, USA. dkarantanis@nuclmed.net
authors: Dimitrios
authors: D
authors: Karantanis
authors: Rathan M
authors: RM
authors: Subramaniam
authors: Brian P
authors: BP
authors: Mullan
authors: Patrick J
authors: PJ
authors: Peller
authors: Gregory A
authors: GA
authors: Wiseman
mesh_terms: D000328:Adult; D000368:Aged; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D005189:False Positive Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging / Q000556:secondary; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D014057:Tomography, X-Ray Computed; D051598:Whole Body Imaging
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18