Objective:To investigate the diagnostic value of multi-slice spiral CT(MSCT)perfusion imaging parameters in the differential diagnosis of benign and malignant solitary pulmonary nodules(SPN).Methods:A total of 80 patients with SPN admitted to our hospital from Oct 2021 to Oct 2022 were selected.All patients underwent MSCT perfusion imaging and pathological examination after admission.According to the histopathological examination results,the patients were divided into benign nodule group and malignant nodule group.MSCT perfusion imaging parameters(blood volume,mean transit time,blood flow,surface permeability coefficient)of the two groups were compared.Receiver operating characteristic(ROC)curve was used to analyze the value of MSCT perfusion imaging parameters in the differential diagnosis of benign and malignant SPN.Results:Among the 80 patients with SPN,47 were diagnosed as malignant nodules and 33 as benign nodules by pathological examination.There was no significant difference in mean transit time between 2 groups(P＞0.05).The blood volume,blood flow and surface permeability coefficient in malignant nodule group were higher than those of benign nodule group(P＜0.05).The results of ROC curve showed that the area under the curve(AUC)of blood volume,blood flow and surface permeability coefficient separately and in combination were 0.823(95% CI:0.721-0.926),0.855(95% CI:0.761-0.949),0.850(95% CI:0.752-0.948)and 0.963(95% CI:0.924-1.000)for the diagnosis of benign and malignant SPN,all of which had certain diagnostic value.When blood volume,blood flow and surface permeability coefficient were 4.405 ml/100 g,51.325 ml/(min·100 g)and 21.115 ml/(min·100 g),respectively,the best diagnostic efficiency could be obtained,and the combined diagnosis value was higher.Conclusion:The combination of blood volume,blood flow and surface permeability coefficient of MSCT perfusion imaging parameters have high value in the differential diagnosis of benign and malignant SPN,which can provide effective basis for the early diagnosis and treatment of benign and malignant SPN.