CT combined with 3D-CTBA to analyze the vasculature around pulmonary ground glass nodules and its value in diagnosis.

objectiveThe purpose of this study was to analyze the vascular characteristics around pulmonary nodules with a diameter of 10-20mm. To explore their predictive value for the pathological nature of pulmonary nodules, computed tomography (CT) combined with three-dimensional computed tomography-bronchography and angiography (3D-CTBA) technique have been chosen as the method.

methods202 patients who were treated from January 2020 to December 2022 have been studied. They were all diagnosed with pulmonary ground glass nodules (GGNs) and obtained final pathologic results at the Department of Thoracic Surgery of Hebei General Hospital. In the meanwhile, the medical records were complete be enrolled in this study. All patients had underwent a chest CT scan in our hospital. The vessels surrounding the nodules were categorized into four types based on their relationships with the pulmonary nodules on the 3D reconstructed images. Type I (passing through): the vessel passes through the lesion, with no significant change in vessel size or shape throughout the path of travel; Type II (bypassed): vessels pass adjacent to the nodule, but no branch vessels supply the diseased tissue; Type III (twisted/dilated): twisting or thickening of blood vessels passing through the nodule, but no increase in number; Type IV (complex): a more complex vascular system other than those described in the above types, such as with irregular vasodilatation and convergent coexistence of vessels from multiple supply vessels. Data was analyzed by SPSS (version 26.0, Inc, Chicago, USA), with continuous data expressed as mean and standard deviation/Median (IQR), categorical variables expressed as numbers and percentages. For quantitative variables were analyzed using the Kruskal–Wallis test or Mann–Whitney U test. Categorical variables were analyzed using Fisher’s exact test or Chi-square test. Furthermore, the GGN-vessel relationship was compared between patients with microinvasive adenocarcinoma (MIA) and invasive adenocarcinoma (IAC). A P-value ≤ 0.05 was considered statistically significant. The Receiver Operating Characteristic (ROC) curve was used to determine the optimal diameter cut-off values for distinguishing IAC from MIA in nodules measuring 10–20 mm, with the Youden index applied to identify the cut-off value with the highest sensitivity and specificity.

resultsAccording to the pathology, all patients were divided into 3 groups:Benign nodule group (32 cases. 2 cases are sclerosing pneumoblastoma. 18 cases are found inflammatory lesions. 2 cases are pulmonary sarcoidosis. 1 case is pulmonary cyst. 7 cases are pulmonary hamartoma. 2 cases are pulmonary tuberculosis). Pre-infiltrative lesion group (36 cases. 4 cases are atypical adenomatous hyperplasia (AAH). 32 cases are adenocarcinoma in situ(AIS)). Infiltrative adenocarcinoma group (134 cases. 48 cases are MIA. 86 cases are IAC). The diameter of the pulmonary nodules of each group is: 13.0(11.0–14.7)mm, 13.0(12.0–15.0)mm, and 16.0(14.0–18.0)mm. The difference is statistically significant (P ≤ 0.001). 101 cases of mixed ground glass nodules (mGGNs) were found in all invasive adenocarcinoma groups and count a percentage of 75.4% (P ≤ 0.001). In invasive adenocarcinoma group, Type III (28/31) counts 90.3% (P = 0.009) and type IV (21/23) counts 91.3% (P = 0.008). This result is statistically different. The combination of type III and type IV vascular relationships showed a significant difference in the differential diagnostic value of the three groups of lung nodules (P < 0.001). For nodules 10–20 mm in diameter, the diameter cut-off value for IAC and MIA was 13.5 mm (AUC = 0.814, 95% CI: 0.74–0.89; specificity = 96.5%, sensitivity = 52.1%). The presence of Type IV vascular relationships in pure ground-glass nodules (pGGNs) showed a significant association with invasive adenocarcinoma (P = 0.038). Moreover, this vascular pattern demonstrated a significantly higher prevalence in invasive adenocarcinoma compared to pre-invasive lesions (P < 0.001). The different types of vessels ( arteries, veins, arteries and veins) crossing the nodule were analyzed showing no statistically significant difference (P = 0.078).

conclusionFor nodules with diameters of 10–20 mm, the presence of type III and IV vascular relationships in surrounding vasculature, a solid component, and a diameter ≥ 13.5 mm are more indicative of invasive lesions.