Usefulness of fluorodeoxyglucose positron emission tomography in malignancy of pulmonary artery mimicking pulmonary embolism

Background The role of 18 F ‐fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F ‐ FDG PET / CT ) in evaluating pulmonary artery lesions has not yet been established. The purpose of this study is to evaluate the usefulness of 18 F ‐ FDG PET / CT imaging in differentiating malignant from benign pulmonary artery ( PA ) lesions. Methods In this retrospective study, 18 subjects with 26 low‐attenuated filling defects suspicious for PA malignancy on contrast‐enhanced chest CT were enrolled; all of whom subsequently underwent 18 F ‐ FDG PET / CT . The maximum standardized uptake value ( SUVmax ) for all PA lesions, defined as the 18 F ‐ FDG uptake, was measured. The final diagnosis was then determined by pathological findings, follow‐up chest CT or clinical follow‐up, and compared with the PET imaging. Results In total, 6 PA sarcomas, 5 tumour embolism, and 15 pulmonary thromboembolism ( PTE ) occurred in this cohort. Not only was the SUVmax of the malignant PA lesions (10.2 ± 10.8) was significantly higher than that associated with PTE (1.7 ± 0.3; P  < 0.001), no overlap occurred between groups. Conversely, no statistically significant difference in SUVmax occurred between PA sarcomas (12.8 ± 14.7) and tumour embolism (7.0 ± 1.32; P  = 1.000). Conclusions   18 F ‐ FDG PET / CT is a useful imaging modality for differentiating malignant from benign PA lesions in patients with inconclusive low‐attenuation filling defects on contrast‐enhanced chest CT .