ObjectiveTo analyze the difference of location identification of pulmonary nodules in two dimensional (2D) and three dimensional (3D) images, and to discuss the identification methods and clinical significance of pulmonary nodules location in 3D space.MethodsThe clinical data of 105 patients undergoing sublobectomy in the Department of Thoracic Surgery, the First Affiliated Hospital with Nanjing Medical University from December 2018 to December 2019 were analyzed retrospectively. There were 28 males and 77 females, with an average age of 57.21±13.19 years. The nodule location was determined by traditional 2D method and 3D depth ratio method respectively, and the differences were compared.ResultsA total of 30 nodules had different position identification between the two methods, among which 25 nodules in the inner or middle zone of 2D image were located in the peripheral region of 3D image. The overall differences between the two methods were statistically significant (P<0.05). The diagnostic consistency rates of two methods were 66.67% in the right upper lung, 83.33% in the right middle lung, 73.68% in the right lower lung, 75.76% in the left upper lung, and 64.71% in the left lower lung. In each lung lobe, the difference between the two methods in the right upper lung (P=0.014) and the left upper lung (P=0.019) was statistically significant, while in the right middle lung (P=1.000), right lower lung (P=0.460) and left lower lung (P=0.162) were not statistically significant.ConclusionThe 3D position definition of lung nodules based on depth ratio is more accurate than the traditional 2D definition, which is helpful for preoperative planning of sublobectomy.