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Objective:Toassessthefeasibilityofusingvirtualnon-contrastCTscanofspectralCTmaterialsuppressediodine(MSI)images toreplacetraditionalunenhancedCT(TNC)imagesinliver. Methods:TheethicscommitteeofthecentralhospitalofPanyuhadapprovedthestudyandinformedconsentwasobtained fromeverypatientpriortotheexamination.32patients(2abscessofliver,6hepaticcystand6cavernoushemangiomaofliver) underwent3-phaseabdominalCTwereretrospectivelyanalyzed.PlainCTwasperformedwithconventional120kVp.The contrast-enhancedscansinthearterialphase(AP)andportalvenousphase(VP)wereperformedwithspectralCTimagingmode. MSIimagesweregeneratedfromtheAPandVPspectralCTimages.MeanCTvaluesforhepatictissueandabdominalaortaon arterial,veinanddelayphasesonMSIandTrueNon-ContrastCTscanweremeasuredandcompared.WemanuallydrewtheROIs ofnormalhepatictissues(atrightanterior,rightposteriorandleftlaterallobeofliver)andabdominalaorta.Thedifferenceof meanCTvaluesbetweenMSIandTNCimagesofliverandabdominalaortawasevaluatedusingpairedttest.Wethencalculated thenormalizedMSICTimagesvalues,bynormalizedMSICTvaluesofliver=MSICTvaluesofliver-(MSICTvaluesofabdominal aorta-CTvaluesofabdominalaorta)ofeachphase.ThedifferenceofmeanCTvaluesbetween,normalizedMSIandTNC imagesofliverwasevaluatedusingpairedttest. Results:ThemeanCTvaluesofMSIandTNCimagesofliverandabdominalaortaonarterial,veinanddelayphaseswere significantlydifferent(p<0.001).ThemeanCTvaluesofnormalizedMSIandTNCimagesofliveronarterial,veinphasehave significantdifference(p=0.00;p=0.07).However,afterthenormalizationprocedure,thecalculatedmeanCTvaluesofMSIand TNCimagesofliverinthedelayphasewere(58.53±10.72)HUand(60.65±9.61)HUrespectively,whichisnotsignificantly different(p=0.22),indicatingthenormalizedMSIcanbeusedassurrogate. Conclusions:NormalizedMSIimagingondelayphasecanbeapotentialsubstitutefortraditionalunenhancedimaging.More importantlythisapproachwillsubstantiallyreducetheradiationdoses.