Abstract： Objective:To explore the differential diagnostic value of multi-slice spiral CT(MSCT)signs on papillary thyroid microcarcinoma(PTMC)and micronodular goiter(MNG).Methods:Clinical data of 50 patients with PTMC and 50 patients with MNG admitted to Qidong People's Hospital were retrospectively analyzed from January 2018 to May 2023.All patients un-derwent MSCT examination,and the differential diagnostic value of MSCT on PTMC and MNG was evaluated.MSCT signs of the two groups were compared.Multivariate Logistic regression analysis was used to explore the influencing factors of PTMC based on MSCT signs.Results:The sensitivity,specificity and accuracy of MSCT in the differential diagnosis of PTMC and MNG were 92.00％(46/50),96.00％(48/50)and 94.00％(94/100),and the consistency Kappa value with pathological diagnosis was 0.880.There were statistical differences between PTMC and MNG in MSCT signs such as lesion count,nodule boundary,presence or absence of calcification,morphology of calcification,envelope integrity,enhancement pattern,enhancement degree,cervical lymph node abnormalities and presence or absence of cystic change.(P＜0.05).The MSCT signs of PTMC were mainly characterized by single lesion,blurred boundary,envelope interruption and obvious enhancement after enhanced scan,while the MSCT signs of MNG patients were mainly characterized by multiple lesions,clear boundary,intact envelope and cystic change.Multivariate Logistic regression analysis showed that among the MSCT signs,single lesion,blurred boundary,envelope inter-ruption,△CT value＞60 HU,cervical lymph node abnormality and absence of cystic change were independent influencing fac-tors of PTMC(P＜0.05).Conclusion:There are obvious differences between PTMC and MNG in single lesion,nodule boundary,envelope integrity,enhancement degree and lymph node abnormality.MSCT is of high value in the differential diagnosis of PTMC and MNG.