Abstract: Objective The multi-slice spiral CT signs and PET/CT semi-quantitative analysis of the isolated tuberculosis cavity and cancerous cavity were compared to explore the differential value of the two cavities. Method 38 patients with single tuberculosis cavity and 28 patients with a lung cancer cavity confirmed by pathology and clinical records from January 2020 to September 2022 in People's Hospital of Longhua Shenzhen were retrospectively analyzed. MSCT scan was performed on all patients, the clinical basic data and CT imaging findings were compared. At the same time, the clinical data of isolated tuberculosis cavitary and lung cancer cavitary patients who were pathologically confirmed by ¹⁸F-FDG PET/CT examination in Jiangxi People's Hospital were collected, and the metabolic characteristics were compared. Result The main onset age of tuberculosis cavity was (36.32±14.68) years, and the main manifestations were thick wall and uniform thickness, with satellite foci around the lesion. The main onset age of cancerous cavity was (63.75±12.92) years. A carcinomatous cavern was mostly characterized by thick wall (thicker than the tuberculosis cavity), uneven inner margins, internal partitions, and wall nodules. Lobed、burr and ground glass density metastasis were seen. The proportions of intra-spacer, inner wall disjointed, wall nodule, bronchial signs were seen around the cavernous focus. The morphology was mainly type IV, and some signs of interruption, thick-walled cavity, lobed sign,stubble burr sign, ground glass density sign,andmetastasis sign in lung cancer cavity were higher than those in single tuberculosis cavity (P<0.05), while the proportions of the satellite foci, long thin burr sign,and wall calcification were lower than those in single tuberculosis cavity (P<0.05). There was no significant difference in gender、cavity site、cavity mean diameter 、vascular cluster sign and pleural depression sign between the two groups (P>0.05). The SUVmax value of lung cancer cavity group was (11.41±6.55), and that of the pulmonary tuberculosis cavity group was (5.96±3.55), with significant difference between the two groups (P=0.038). The SUVmax value of squamous cell carcinoma (13.66±7.20) >adenocarcinoma (10.28±5.60), the difference was not statistically significant (P=0.293). Conclusion There are some imaging and metabolic differences between the tuberculosis cavity and the cancerous cavity, multi-slice spiral CT combined with ¹⁸F-FDG PET/CT can accurately distinguish the tuberculosis cavity from the lung cancer cavity, which is worthy of clinical promotion and application.

Key words: Multi-slice spiral CT, Positron emission computed tomography, Tuberculosis cavity, Lung cancer cavity, Differential diagnosis