Objective To explore the diagnostic value of PET-CT and PET-CT combined with lung volume computed assisted reading(Lung VCAR)software in hilar area lymph nodes.

Methods Preoperative whole body PET-CT imaging was performed in 49 patients who were highly suspicious of non-small cell lung cancer. PET-CT images of the hilar area lymph nodes and the PET-CT images of the hilar area lymph nodes from Lung VCAR software were evaluated by two experienced doctors, and then compared with the pathological diagnosis.

Results There was no significant difference between the CT values of benign and malignant lymph nodes (t=-1.40, P > 0.05). But a significant difference was existed between the benign and malignant hilar lymph nodes with the density visual analysis, the lymph short diameter and the maximum of standardized uptake value(SUV_max)(χ²=30.37, 27.40, 20.06, all P < 0.05). The sensibility, specificity and accuracy of PET-CT in diagnosis of the hilar area lymph nodes were 76.5%、90.7%、88.3% respectively, and the accuracy of the diagnosis was significantly higher than that of CT and PET alone(χ²=15.27, P < 0.05) using the lymph short diameter≥1 cm of CT, the density of lymph node is equal to (slightly lower than) the same layer vascular density and the lymph node SUV_max≥2.5 of PET as the diagnostic criteria. One hundred and three hilar area lymph nodes were diagnosed by PET-CT and four nodes were not hilar lymph nodes proved by the Lung VCAR software (3 hilar vascular uptake, 1 bronchial cartilage).

Conclusion The methods of PET-CT lymph visual density analysis plus lymph node diameter and SUV_max had a high diagnostic accuracy of non-small cell lung hilar lymph. For the PET-CT, the pulmonary vascular uptake was the main cause affecting the discrimination of hilar lymph nodes, while Lung VCAR software was helpful to diagnosis.