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

The role of ¹⁸F‐fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F‐FDG PET/CT) in evaluating pulmonary artery lesions has not yet been established. The purpose of this study is to evaluate the usefulness of ¹⁸F‐FDG PET/CT imaging in differentiating malignant from benign pulmonary artery (PA) lesions.

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 ¹⁸F‐FDG PET/CT. The maximum standardized uptake value (SUVmax) for all PA lesions, defined as the ¹⁸F‐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.

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).

 ¹⁸F‐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.