False Positive and False Negative FDG-PET Scans in Various Thoracic Diseases

Abstract

Fluorodeoxyglucose (FDG)-positron emission tomography (PET) is being used more and more to differentiate benign from malignant focal lesions and it has been shown to be more efficacious than conventional chest computed tomography (CT). However, FDG is not a cancer-specific agent, and false positive findings in benign diseases have been reported. Infectious diseases (mycobacterial, fungal, bacterial infection), sarcoidosis, radiation pneumonitis and post-operative surgical conditions have shown intense uptake on PET scan. On the other hand, tumors with low glycolytic activity such as adenomas, bronchioloalveolar carcinomas, carcinoid tumors, low grade lymphomas and small sized tumors have revealed false negative findings on PET scan. Furthermore, in diseases located near the physiologic uptake sites (heart, bladder, kidney, and liver), FDG-PET should be complemented with other imaging modalities to confirm results and to minimize false negative findings. Familiarity with these false positive and negative findings will help radiologists interpret PET scans more accurately and also will help to determine the significance of the findings. In this review, we illustrate false positive and negative findings of PET scan in a variety of diseases.

Relationship between [ 14 C]MeAIB uptake and amino acid transporter family gene expression levels or proliferative activity in a pilot study in human carcinoma cells: Comparison with [ 3 H]methionine uptake

“…PET-CT imaging is based on the preferential uptake of [ 18 [2,3]. However, the specificity of this technique is low in patients with active infections and inflammatory diseases (because of high FDG uptake in macrophages) and in the brain (because of high background FDG uptake) [4,5]. Therefore, the development of post-FDG radiopharmaceuticals is needed.…”

Ability of integrated positron emission and computed tomography to detect significant colonic pathology

“…11,14 Furthermore, PET-CT does not detect all clinically relevant lesions. 15,16 Thus, although it has been proposed as a new way of diagnosing and monitoring colonic diseases, PET-CT has a significant falsepositive rate and a poorly defined false-negative rate for colon pathology.…”

Breast Sparganosis Incidentally Detected by FDG PET/CT

“…This migrating tendency of the larva also induces the inflammation of the surrounding tissues to varied extent. Hence, breast sparganosis generates various enhancing patterns, from delayed to progressive enhancements, on breast MR according to the perilesional edema and the surrounding inflammatory reaction [17,19,20].…”

“…Several cases have been reported to have high FDG uptake (SUV max 3.9~4.0) in pulmonary paragonimiasis [21]. Active inflammatory processes, including eosinophil infiltration in response to viable worms, can cause high FDG uptake in the infected sites [20]. It is known to elicit various degrees of immune reactions according to parasite types, infection site, host immune status, etc., which could be attributed to the broad spectrum of FDG uptake in parasitic infection.…”