RESUMO
Objective Toexplorethevalueofmonochromaticenergyimaginggeneratedfrom RevolutionCTindetectingcoronary plaquesindifferentconcentrationsofcontrastagent.Methods Sixtesttubesnumbered3,4,5,6,8and9inthephantom wereselectedand filledupwithdifferentconcentrationsofiodinesolutions(20,10,5,2.5,0,13mgI/mL,respectively),fishbonesimulatingcalcified plaqueandstreakyporksimulatinglipid/fibrousplaque.EachtubeunderwentspectralCTscan(studygroup,70keV monochromatic energyimaging)and120kVpCTscan (controlgroup)respectivelyinRevolutionCT.Theabilityofplaquedetectionwasevaluated subjectively,andfurtheranalysis was madeontheimages withascoregreaterthanorequaltothreepoints.One-way ANOVA and Bonferroni m ethod w ere used to co m pare the C T values and C N R in different tubes in the intra-group co m parison ,w hile paired t test and M ann-W hitney U testwereusedfortheinter-groupcomparison.Results TheoverallimagequalityofNo.4,5and9testtubes inbothgroupsmettheclinicaldiagnosticlevel.Intheintra-groupcomparison,No.5testtubeshowedhigherCNRofcalcifiedplaque andNo.9testtubeshowedhigherCNRoflipidplaqueandfibrousplaquethantheothers(t=4.105-29.214,allP<0.001).Whilein theinter-groupcomparison,thestudygroupshowedsimilarCNRofcalcifiedplaqueinNo.9testtube(t=-1.576,P=0.130)tothecontrol group,andhigherCNRintheothersthanthecontrolgroup(Z=-4.074--3.815,t=-14.782--3.520,allP<0.05).Conclusion Comparedwith120kVpCTimages,monochromaticenergyimagingat70keVfrom RevolutionCTshowedbetteroverallimagequality andcoulddisplaycoronaryplaquesbetterwiththecontrastagent concentrationfrom5mgI/mLto13mgI/mL.
