重建算法对SPECT空间分辨力的影响.pdf

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1、·13O·中国医学影像技术2014年第30卷第1期ChinJMedImagingTechnol，2014，VolNo1．●影像技术学ImpactofreconstructionalgorithmonspatialresolutionofSPECTLUOFei，GENGJian—hua，ZOUZuo—wei，HONGHao，ZHAOWei—qiang，ZHENGRong(DepartmentofNuclearMedicine，CancerHospital，ChineseAcademyofMedicalSciences&PekingUni

2、onMedicalCollege。Beijing100021，China)[-Abstract]ObjectiveToinvestigatetheimpactofreconstructionalgorithmonspatialresolutionofSPECT．MethodsImagingofancylinderresolutionphantomwasperformedusingSiemensSymbiaTSPECTequipmentwithparallelholelow—energyhigh—resolutioncollimator

3、．Inlongaxisdirectionoftheresolutionmodel，therewere5parallellinesources．Theacquisitionconditionwascontourwithstepandshootmode．Allacquisitionswerereconstructedusingbothfilteredbackprojection(FBP)anditerativemethod，includingHannandButterworthinthreecutofffrequencies，Flash3

4、Dandorderedsubsetsexpectationmaximization(OSEM)2DinfiveGaussiankernelfunctionwidths．Thereconstructedimageswithdif—ferentalgorithmsandparameterswereanalyzed．Theresolutionoflineresolutionspreadfunctionwasevaluatedbyfullwidthathalfmaximum(FWHM)value．ThenFWHMvaluesof51ineso

5、urcesin6differentsectionswerecalculatedtan—gentially，radiallyandaxially．Statisticalmethodofmultiplelinearregressionwasusedtoanalyzetheimpactofdifferentre—constructionalgorithmsandparameters．ResultsFWHMvaluesforFBPreducedwiththecutofffrequenciesincreased，thehigherthecuto

6、ff，thebettertheresolution．Inthesamecut—offfrequency，FWHMofButterworthwassmallerthanthatofHann，andstatisticaldifferenceswerefoundbetweenthetwomethods．IniterativemethodFWHMincreasedwhenGaussi—ankernelfunctionwidthsincreased．Nostatistica1differenceofFWHMbetweenFlash3DandOS

7、EMalgorithminradia1andtangentialresolution，whereasaxialFWHMofFlash3DwasstatisticallysmallerthanthatofOSEMalgorithm．Con—clusionReconstructionalgorithmhasgreatimpactonspatialresolutionofSPECT．Thealgorithmandparametersshouldbeappropriatelyselectedforclinica1practice．[Keywo

8、rds]Tomography，emission—computed，single-photon；Reconstructionalgorithm；Resolution；Influencingfactors重建算法对SPECT