Possible Causes of False-Positive Findings in 18F-FDG PET Studies in Chest
| Category, location, and finding | Cause |
|---|---|
| Infection or Inflammation | |
| Lung | |
| Fungal | Aspergillosis; cryptococcosis; blastomycosis; coccidioidomycosis |
| Mycobacterial | Active tuberculosis; atypical mycobacteriosis |
| Bacterial | Pneumonia; abscess; nocardiosis |
| Granuloma | Granuloma; necrotizing granuloma; sarcoidosis; Wegener granulomatosis; plasma cell granuloma; histoplasma granuloma; rheumatoid arthritis–associated lung disease |
| Interstitial fibrosis | Radiation pneumonitis; fibrosing alveolitis |
| Occupational | Inflammatory anthracosilicosis |
| Allergic | Airway inflammation with asthma |
| Nonspecific | Inflammation; acute inflammation with bronchiectasis and atelectasis; reactive mesothelial cell; tumor necrosis; histiocytic infiltrate; inflammatory pseudotumor; fibrous histiocytic infiltrate; aspiration pneumonia with barium; aspiration pneumonia with salivary and tracheal secretions; organizing pneumonia |
| Pleura | Pleural effusion; empyema |
| Mediastinum (esophagus) | Esophagitis |
| Benign tumor | |
| Mediastinum (lymph node) | Chronic nonspecific lymphadenitis; cryptococcosis; tuberculosis; anthracosilicosis; active granuloma |
| Pleura | Fibrous mesothelioma |
| Nerve root | Schwannoma; aggressive neurofibroma |
| Bone | Chondrohamartoma; enchondroma |
| Physiologic uptake | |
| Muscle | Hypermetabolism after physical activity |
| Thymus | Normal until puberty; hyperplasia after chemotherapy |
| Bone marrow | Hyperplasia after chemotherapy |
| Brown fat | Nonshivering thermoregulation |
| Iatrogenic | |
| Skin and soft tissue | Open lung biopsy; irradiation |
| Trachea | Tracheostomy tube |
Reprinted with permission of Edizioni Minerva Medica (109).