PURPOSETo investigate the multi-slice spiral Computed Tomography(MSCT) findings of chest involvement in IgG4-related diseases and to improve doctors' understanding of this disease.MATERIALS AND METHODSWe retrospectively analyzed the clinical and imaging data of 67 patients with clinically confirmed or suspected IgG4-related diseases.RESULTSSixty patients (89.60%) had abnormal chest CT findings. Among them, 47 patients (70.10%) had enlarged mediastinal lymph nodes. Thickening of the tracheal and tracheobronchial perivascular walls was observed in 35 patients (52.20%). Nodules were observed in 29 patients (43.30%). Patches or ground-glass opacities were observed in 15 cases (22.40%); bilateral enlarged axillary lymph nodes, 9 (13.40%); bilateral enlarged hilar lymph nodes, 3 (4.50%); and, interstitial changes, 3 (11.90%). Pleural and pericardial effusion occurred in five cases (7.46%, two bilateral and three unilateral) and three cases (4.50%), respectively. Seven (10.45%) patients showed no obvious abnormalities. The abnormally elevated IgG4 level (>135 mg/dL) was positively correlated with thickening of the tracheal and tracheobronchial walls (r = 0.328, p = 0.007) and enlargement of mediastinal lymph nodes (r = -0.252, p = 0.039), and the logistic regression model 1 showed that the incidence of lung as the first symptom was higher in patients with bilateral enlarged hilar lymph nodes on chest images.CONCLUSIONChest CT is of great significance for the diagnosis and follow-up of IgG4-RLD. Chest CT scans should be suggested to be performed when ocular symptoms, bilateral enlarged hilar lymph nodes, pancreatitis, pituitary adenitis, Takayasu arteritis, or abnormally elevated IgG4 levels (>135 mg/dL) are present, and IgG4-RLD should be considered.