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ID:62108558
大小:6.57 MB
页数:63页
时间:2021-04-16
《最新医学PPT资源_医学影像及其它_CT-成像原理介绍-药学医学精品资料.ppt》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、最新医学PPT资源_医学影像及其它_CT-成像原理介绍-药学医学精品资料ComputedTomographyCTBasicsPrincipleofSpiralCTScanParameter&ImageQualityOptimizingInjectionProtocolsClinicalApplicationsX-RayDiscoveryX-raywasdiscoveredbyaGermanscientistRoentgen100yearsago.Thismadepeopleforthefirsttimebe
2、abletoviewtheanatomystructureofhumanbodywithoutoperationButit'ssuperimposedAndwecouldn'tviewsofttissueHowdoesCTWork?Recon.&postpro.DataacquisitionX-raygenerationX-raygoesthroughcollimatorthereforepenetrateonlyanaxiallayeroftheobject,called"slice"HowdoesCTW
3、ork?PatientisplacedinthecenterofthemeasurementfieldX-rayispassedthroughthepatient’sslicefrommanydirectionalonga360°pathThetransmittedbeamsarecapturedbythedetectorswhichdigitizesthesesignalsThesedigitizedsignalscalledrawdataaresenttoacomputerwhichcreatetheC
4、TimageHowdoesCTWork?Theobjectsliceisdividedintosmallvolumeelementscalledvoxels.EachvoxelisassignedavaluewhichisdependentontheaverageamountofattenuationHowisCTImagegenerated?Theattenuationvaluesaretransferredtothecomputerwheretheyarecoded&usedtocreateaslice
5、imageHowisCTImagegenerated?CTGenerations&Design“Generation”isusedtolabelCTtube-detectordesigns3rdGenerationDesignRotatingtube&detector4thGenerationDesignFixedringdetectorSlip-ringTechnologyPoweristransmittedthroughparallelsetsofconductiveringsinsteadofelec
6、tricalcablesContinuousGantryRotationPrerequisiteforSpiralCTNonSlip-ringScannerSlip-ringScannerComputedTomographyCTBasicsPrincipleofSpiralCTScanParameter&ImageQualityOptimizingInjectionProtocolsClinicalApplicationsWhatisSpiralScan?--just4“C”Continuouslyro
7、tatingtube/detectorsystemContinuouslygeneratingX-rayContinuouslytablefeedContinuouslydataacquisitionReconstructionofarbitraryslices(eithercontiguousoroverlapping)withinthescannedvolumeDistancebetweentheslicesiscalledIncrementABVolumeDataContinuousdataacqui
8、sitionIncrementSliceThicknessIncrement=SliceThicknessNoOverlapNoGapsContiguousImageReconstructionIncrementOverlapSliceThicknessOverlappingImageReconstructionIncrement
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