The Study On The Application Of One-step Spectral And Perfusion CT Imaging In The Diagnosis Of SPN

Objective: To investigate the application value of one-step spectral and perfusion imaging with Aquilion ONE 640-slice CT scanner in the diagnosis of solitary pulmonary nodules(SPN).Method: A total of 82 patients with confirmed pulmonary nodules who were collected and underwent one-step spectral and perfusion imaging.After the images were acquired,the energy spectrum data of each group was processed in the Dual Energy processing program,the iodine concentration(IC)of the lesion and the aorta in the same layer were measured in the generated iodine map,and the standardized iodine concentration(NIC)was abtained.CT perfusion images were reconstructed by primary perfusion data and 80 KVp energy level images which generated from spectral CT through Vitrea workstation.CT perfusion parameters included arterial flow(AF),pulmonary flow(PF)and perfusion index(PI).All the aforem entioned data were measured three times and averaged.Comparison of energy spectrum and perfusion parameter difference between benign and malignant lesions and comparison of energy spectrum and perfusion parameter difference between lung squamous cell carcinoma and adenocarcinoma were analyzed by adopting independent sample t test,and parameters with statistical differences were further analyzed by receive operating characteristic(ROC)curve.The difference(P < 0.05)was considered statistically significant.Result:1.All the 82 patients successfully completed one-step spectral and perfusion scan with high-quality images.The patient's effective dose(ED)was 6.81 m Sv.2.The IC,NIC,AF,PF and PI of all benign lesion were [(52.35 ± 10.17)100ug / ml],(0.74 ± 0.17),[(44.02 ± 16.86)ml /(min · 100 ml)],[(59.21 ± 22.26)ml /(min ·100ml)],(56.22 ± 13.80)%,respectively.The IC,NIC,AF,PF and PI of all malignancies were [(62.34 ± 16.05)100ug / ml],(1.49 ± 0.58),[(63.38 ± 26.39)ml /(min · 100 ml)],[(64.33 ± 29.69)ml /(min ·100 ml)],(48.93 ± 10.31)%.The IC,NIC,AF,and PF in malignant lesions were higher than that in benign lesions,and PI were lower than that in benign lesiosn.Statistically significant difference in IC,NIC,AF,and PI existed between benign and malignant lesion(P <0.05),and the AUC were 0.705,0.924,0.767 and 0.69,respectively.When IC,NIC,AF and PI were combined for the differential diagnosis of benignity and malignancy,AUC was 0.951,and the sensitivity and specificity were 85% and 93.4%,respectively.3.The IC,NIC,AF,PF and PI of lung adenocarcinoma were [(67.78 ± 18.74)100ug /ml],(1.69 ± 0.45),[(76.14 ± 30.75)ml /(min · 100 ml)],[(65.58 ± 30.34)Ml /(min · 100ml)] and(44.38 ± 10.38)%,respectively.And the IC,NIC,AF,PF and PI of ung squamous cell carcinoma were [(55.16 ± 9.23)100ug / ml],(1.04 ± 0.29),[(50.27 ± 15.30)ml /(min · 100 ml)],[(64.98 ± 33.69)ml /(min · 100 ml)],and(53.89± 9.18)%.The IC,NIC,AF,and PF in lung adenocarcinoma were higher than that in lung squamous cell carcinoma,and PI were lower than that in lung squamous cell carcinoma group.Additionally,statistically significant difference were found for IC,NIC,AF,and PI between two types of lung cancer,(P <0.05),and the AUC were 0.717,0.899,0.79,0.746,respectively.When IC,NIC,AF and PI were combined for in the differential diagnosis of lung squamous cell carcinoma and lung adenocarcinoma,the AUC was 0.943,and the sensitivity and specificity were 86.2% and 95.8%,respectively.Conclusion:1.The parameters of IC,NIC,AF,and PI obtained by one-step spectral and perfusion scan could be used for the differential diagnosis of benign and malignant SPN,and combination of those parameters could improve the diagnostic efficiency.2.The difference in IC,NIC,AF,and PI values between lung adenocarcinoma and lung squamous cell carcinoma were statistically significant,and the combination of four parameter values could improve the diagnostic sensitivity and specificity.one-step spectral and perfusion imaging is feasible in the assessment of lung squamous cell carcinoma and adenocarcinoma.