Diagnostic value of FDG PET/CT in determining the etiology of pericardial effusion.

Objective: To analyze the imaging characteristics of FDG PET/CT in pericardial effusions from various etiologies and evaluate its diagnostic utility for differentiating these etiologies.

Methods: A retrospective analysis was conducted on 71 patients who underwent FDG PET/CT imaging for etiological diagnosis of pericardial effusion from 2014 to 2024 in our hospital. Clinical, laboratory, and imaging data from FDG PET/CT were evaluated to characterize pericardial effusions attributable to malignant conditions, bacterial infections, other benign etiologies, and idiopathic causes, thus assessing the diagnostic efficacy of FDG PET/CT.

Results: Pericardial lesions exhibited significant thickening and markedly increased FDG uptake in 89.5% of malignant cases and 77.8% of bacterial infection cases. When integrated with extrapericardial imaging findings, FDG PET/CT directly identified the underlying etiology in 68.4% of malignant and 44.4% of bacterial infection cases. Employing an integrated "clinical-laboratory-imaging" diagnostic approach, the positive diagnostic rate of FDG PET/CT increased to 56.3%, and FDG PET/CT was able to achieve etiologically suggestive imaging diagnoses in 100% of malignant cases, 77.8% of bacterial cases, and 47.8% overall. Ultimately, FDG PET/CT contributed to clinical management in 88.7% of patients.

Conclusion: FDG PET/CT is valuable for the etiological diagnosis of pericardial effusions. Developing a comprehensive "clinical-laboratory-imaging" diagnostic model can substantially enhance the effectiveness of FDG PET/CT in determining the underlying causes of pericardial effusion.