Objective: This study aimed to assess the clinical value of 4D fluorine-18-fluorodeoxyglucose PET/computed tomography (F-FDG PET/CT) in the differential diagnosis for lung lesions.
Patients and methods: Fifty-eight patients with lung lesions including lung cancer, pneumonia nodules, and benign pulmonary nodules were enrolled. The PET/CT scan was performed immediately (15 min of dynamic scan), at 60 min (early scan), and at 120 min (delayed scan) after the injection of F-FDG. The time-activity curves (TACs) were generated from the dynamic PET. The maximum standardized uptake value (SUVmax) of each lesion at early and delayed scans was measured, and the retention index of SUVmax (RI-SUVmax) was calculated. The cutoff values for SUVmax were determined.
Results: Lung cancer lesions (27/31, 87.1%) exhibited a continuously rising slope of TAC, whereas pneumonia lesions (13/15, 86.66%) and benign pulmonary nodules (12/12, 100%) exhibited a continuously decreasing slope of TAC. The early-SUVmax and delayed-SUVmax in the pneumonia group were significantly lower than those in the lung cancer group, whereas notably higher than those in the benign pulmonary nodules group. The diagnostic accuracy was: delayed-SUVmax > early-SUVmax > RI-SUVmax.
Conclusion: The 4D F-FDG PET/CT exhibited excellent performance with high accuracy in the dynamic PET/CT.