Diagnostic Value Of Dual-detector Spectral CT In Solitary Benign And Malignant Pulmonary Nodules

Objective:To investigate the diagnostic value of spectral CT quantitative parameters with double detector in solitary benign and malignant pulmonary nodules.Materials and Methods:From September 2019 to June 2021,58 cases of isolated pulmonary nodules were retrospectively and consecutively enrolled,all of which were scanned by dual-stage spectral CT before surgery or treatment.Pathological results were found in 58 cases of pulmonary nodules,and it was used as the gold standard.based on spectral CT iodine map and effective atomic number map,Iodine concentration(IC)and effective atomic number(E-FF Z)were quantitatively measured in lung leasions,adjacent lung tissues and normal lung tissues at the same level.Meanwhile,iodine concentration in aorta at the same level was measured.The above data were calculated by standard iodine concentration(NIC)and measured by plain CT and arterial phase and venous phase respectively First,the data were tested for shapiro-Wilk(SW).The quantitative data in conformity with normal distribution were tested by independent sample T test,while those in conformity with rank-sum test were compared.The accuracy of spectral CT in diagnosing benign and malignant pulmonary nodules was evaluated by receiver operating Characteristic curve(ROC).Results:1.Among 158 cases of pulmonary nodules,43 cases were malignant nodules and15 cases were benign nodules.There was no statistically significant difference in clinical characteristics,including age and gender,smoking history in the differential diagnosis of benign and malignant pulmonary nodules.Malignant nodules were slightly older,and males were slightly more than females.2.For the internal characteristics of nodules,NIC in arterial stage was significantly different between the two groups(P=0.030),and the NIC in malignant stage was higher than that in benign group(NIC in malignant group =0.11±0.08mg/ mL,NIC in benign group =0.07±0.03mg/ mL),and for NIC in venous stage and plain scan e-FF Z,there was no statistically significant difference in between the two groups(P = 0.167,0.291,respectively).3.For the influence of pulmonary tissue perfusion adjacent to benign and malignant nodules,the difference of IC and E-FF Z in pulmonary tissue adjacent to the lesion at the arteriovenous stage,the difference of lung tissue around the lesion and normal lung tissue at the same level between benign and malignant groups was statistically significant(P<0.05).4.ROC curve was used to evaluate the diagnostic efficacy of spectral CT parameters for benign and malignant pulmonary nodules:IC and E-FF Z of the lung leasions,leasions adjacent to lung tissue and difference were of certain significance.The area under curve NIC difference of lung tissue on the side of lesions and on the opposite side of lung tissue at arterial stage is the largest(P=0.880),the sensitivity was 90.0% and the specificity was 73.3%.Conclusion:The iodine concentration and effective atomic number of dual-detector spectral CT have certain diagnostic efficacy in the differential diagnosis of benign and malignant pulmonary nodules,providing a new tool for the diagnosis of pulmonary nodules.