Objective:Thisstudyinvestigatedthecapabilityofdual-energyspectralcomputedtomography(CT)toquantitativelyevaluatelungperfusiondefectsthatareinducedbycentrallungcancer.Methods:Thirty-twopatientswithcentrallungcancerunderwentCTangiographyusingspectralimaging.Aunivariategenerallinearmodelwasconductedtoanalyzethevarianceofiodineconcentration/CTvaluewiththreefactorsoflungfields.Apairedt-testwasusedtocompareiodineconcentrationsandCTvaluesbetweenthedistalendoflungcancerandthecorrespondingareainthecontralateralnormallung.Results:Iodineconcentrationsincreasedprogressivelyinthefar,intermediateandneargroundsidesinthenormallungfieldsat0.60±0.28,0.93±0.27and1.25±0.38mg/mL,respectively(P<0.001).ThesametrendwasobservedfortheCTvalues[–(840.64±49.08),–(812.66±50.85)and–(760.83±89.17)HU,P<0.001].Theiodineconcentration(0.70±0.42mg/mL)ofthelungfieldinthedistalendoflungcancerwassignificantlylowerthanthecorrespondingareainthecontralateralnormallung(1.19±0.62mg/mL)(t=–7.23,P<0.001).However,theCTvalueoflungfieldinthedistalendoflungcancerwassignificantlyhigherthanthecorrespondingareainthecontralateralnormallung[–(765.29±93.34)HUvs.–(800.07±76.18)HU,t=3.564,P=0.001].Conclusions:SpectralCTimagingbasedonthespectraldifferentiationofiodineisfeasibleandcanquantitativelyevaluatepulmonaryperfusionandidentifyperfusiondefectsthatareinducedbycentrallungcancer.SpectralCTseemstobeapromisingtechniqueforthesimultaneousevaluationofbothmorphologicalandfunctionallunginformation.