Application Research Of One-step Spectral And Perfusion CT Scan In Differential Diagnosis And Assessing Chemotherapy Effect Of Lung Cancer

Part One Application research of one-step spectral and perfusion CT Scan in differential diagnosis of Lung lesions Objective:To investigate the value of spectral and perfusion parameters in one-step spectral and perfusion CT scan in differential diagnosis of lung lesions.Materials and Methods:One hundred and twenty-nine patients with lung lesions were prospectively collected and underwent one-step spectral and perfusion imaging with GE Revolution CT from January 2018 to March 2019.CT perfusion images were reconstructed by primary perfusion data and 100 kVp-like energy level images which generated from spectral CT.CT perfusion parameters including blood volume(BV),blood flow(BF),mean transit time(MTT),permeability surface(PS)and spectral parameters including iodine concentration(IC),slope rate of spectral curve in both arterial and venous phase(40~70 keV,40~100 keV and 40~140 keV,k1 to k6)between benign(n=38)and malignant(n=91)tumors were measured and calculated.Different parameters were compared and receiver operating characteristics(ROC)curves were taken to give the diagnostic efficiency and the diagnostic sensitivity and specificity.Results:The BV,BF and PS in malignant were higher than benign lesion and the AUC were0.835,0.829,0.803 respectively,the sensitivity of PS was 80.2% and the specificity only was 57.9%.The sensitivity,specificity,accuracy of BV,BF were 85.7%,68.4%,80.6% and 83.5%,71.1%,79.8%.The k1 to k5 and IC in arterial(IC-AP),IC in venous(IC-VP)in malignant were higher than benign lesion and the AUC were 0.822,0.747,0.712,0.723,0.627,0.833 and 0.731 respectively.The AUC of k1 was higher than k2 to k5 and IC-AP was higher than IC-VP.The sensitivity,specificity,accuracy of k1 and IC-AP were 81.3%,68.4%,77.5% and 84.6%,71.1%,80.6%.Combination BV,BF with k1,IC-AP differential diagnosis the lung lesions with AUC 0.934 and sensitivity,specificity,accuracy were 90.1%,86.8%,89.1% respectively.Conclusion:The parameters BV,BF,k1 and IC-AP of one-step spectral and perfusion scan could used for the differential diagnosis of lung lesions,and combination those parameters could increase the sensitivity,specificity and accuracy.Part Two Application Research of One-step Spectral and Perfusion CT Scan in Assessing chemotherapy effect of Lung cancerObjective:To investigate the value of spectral and perfusion parameters in one-step spectral and perfusion CT scan in assessing chemotherapy effect of lung lesions.Materials and Methods:Thirty-two patients who were treated with chemotherapy and followed up regularly from part one were collected and underwent one-step spectral and perfusion imaging with GE Revolution CT before first and third chemotherapy.CT perfusion images were reconstructed by primary perfusion data and 100 k Vp-like energy level images which generated from spectral CT.CT perfusion parameters including BV,BF,MTT,PS and spectral parameters including IC,slope rate of spectral curve in both arterial and venous phase(40~70 ke V,40~100 ke V and 40~140 ke V,k1 to k6)were measured and calculated.The difference of parameters between first and third scanning were expressed as "?".All patients divided into responders and non-responders by RECIST1.1.Different parameters were compared and ROC were taken to give the diagnostic efficiency and the diagnostic sensitivity and specificity.Results:The perfusion and spectral parameters before treatment have no significant difference between responders and non-responders.The BV,BF,PS and k1,k2,k4IC-AP and IC-VP in responders after treatment were lower than before treatment and non-responders after treatment.After treatment,the variation of BV,BF,k1 and IC-AP were higher than others,and the AUC were 0.811,0.823,0.810 and 0.819 respectively,the sensitivity were 71.4%,76.2%,71.4% and 76.2% respectively,,the specificity were72.7%,81.8%,63.6% and 72.7% respectively,the accuracy were71.9%,78.1%,68.8% and 75.0% respectively.Combination BV,BF with k1,IC-AP assess effect with AUC 0.897 and sensitivity,specificity,accuracy were 85.7%,81.8%,84.4% respectively.Conclusion:The partial parameters of one-step spectral and perfusion scan could used to assess the effect of lung cancer after chemotherapy early and combination BV,BF,k1 and IC-AP could increase the sensitivity,specificity and accuracy.