Abstract: Objective:To evaluate the diagnostic value of chest multi-slice spiral CT in breast mass. Methods:Imaging data of preoperative chest MSCT and mammography in 72 patients with breast masses confirmed by surgical pathology were collected. There were 54 cases of malignant breast mass and 18 cases of benign breast mass. Patients were divided into non-dense group (23 cases) and dense group (49 cases) according to the types of breast glands. Taking pathological examination results as reference, the diagnostic efficiency of breast masses in chest MSCT and mammography was evaluated. Results:In the dense breast group, the diagnostic accuracy of chest MSCT for malignant mass was 89.19%, higher than that of mammography 67.57%, and the difference was statistically significant (P=0.024, χ²=5.103); the diagnostic accuracy of chest MSCT for benign mass was 75% higher than that of mammography 58.33%. In the non-dense breast group, the diagnostic accuracy of mammography for malignant mass was 94.12%, slightly higher than chest MSCT of 82.35%. The diagnostic accuracy of chest MSCT and mammography for all breast masses was 86.11% and 75%. The detection rate of chest MSCT for metastatic lymph nodes and chest metastases was better than that of mammography. Conclusion:Breast MSCT has high value in qualitative diagnosis of breast mass. Chest MSCT can provide more information and improve the diagnostic accuracy of dense breast mass than mammography.