What is a CT Scan? Procedure, Risks, and Results - Healthline

A computerized tomography scan (CT or CAT scan) uses computers and rotating X-ray machines to create cross-sectional images of the body. These images provide ... HealthlineHealthConditionsDiscoverPlanConnectSubscribeFitnessGetMotivatedFindYourMovementLevelUpExercise+ConditionsRestandRecoverSupportYourJourneyExercisewithUsCT(ComputedTomography)ScanMedicallyreviewedbyWilliamMorrison,M.D.—WrittenbyHeatherRoss—UpdatedonDecember19,2017PurposeProcedureRisksResultsWhatIsaCTScan?Acomputerizedtomographyscan(CTorCATscan)usescomputersandrotatingX-raymachinestocreatecross-sectionalimagesofthebody.TheseimagesprovidemoredetailedinformationthannormalX-rayimages.Theycanshowthesofttissues,bloodvessels,andbonesinvariouspartsofthebody.ACTscanmaybeusedtovisualizethe:headshouldersspineheartabdomenkneechestDuringaCTscan,youlieinatunnel-likemachinewhiletheinsideofthemachinerotatesandtakesaseriesofX-raysfromdifferentangles.Thesepicturesarethensenttoacomputer,wherethey’recombinedtocreateimagesofslices,orcross-sections,ofthebody.Theymayalsobecombinedtoproducea3-Dimageofaparticularareaofthebody.WhyIsaCTScanPerformed?ACTscanhasmanyuses,butit’sparticularlywell-suitedfordiagnosingdiseasesandevaluatinginjuries.Theimagingtechniquecanhelpyourdoctor:diagnoseinfections,muscledisorders,andbonefracturespinpointthelocationofmassesandtumors(includingcancer)studythebloodvesselsandotherinternalstructuresassesstheextentofinternalinjuriesandinternalbleedingguideprocedures,suchassurgeriesandbiopsiesmonitortheeffectivenessoftreatmentsforcertainmedicalconditions,includingcancerandheartdiseaseThetestisminimallyinvasiveandcanbeconductedquickly.HowIsaCTScanPerformed?YourdoctormaygiveyouaspecialdyecalledacontrastmaterialtohelpinternalstructuresshowupmoreclearlyontheX-rayimages.ThecontrastmaterialblocksX-raysandappearswhiteontheimages,allowingittohighlighttheintestines,bloodvessels,orotherstructuresintheareabeingexamined.Dependingonthepartofyourbodythat’sbeinginspected,youmayneedtodrinkaliquidcontainingthecontrast.Alternatively,thecontrastmayneedtobeinjectedintoyourarmoradministeredthroughyourrectumviaanenema.Ifyourdoctorplansonusingacontrastmaterial,theymayaskyoutofastforfourtosixhoursbeforeyourCTscan.WhenitcomestimetohavetheCTscan,you’llbeaskedtochangeintoahospitalgownandtoremoveanymetalobjects.MetalcaninterferewiththeCTscanresults.Theseitemsincludejewelry,glasses,anddentures.YourdoctorwillthenaskyoutoliefaceuponatablethatslidesintotheCTscanner.They’llleavetheexamroomandgointothecontrolroomwheretheycanseeyouandhearyou.You’llbeabletocommunicatewiththemviaanintercom.Whilethetableslowlymovesyouintothescanner,theX-raymachinewillrotatearoundyou.Eachrotationproducesnumerousimagesofthinslicesofyourbody.Youmayhearclicking,buzzing,andwhirringnoisesduringthescan.Thetablewillmoveafewmillimetersatatimeuntiltheexamisfinished.Theentireproceduremaytakeanywherefrom20minutestoonehour.It’sveryimportanttoliestillwhileCTimagesarebeingtakenbecausemovementcanresultinblurrypictures.Yourdoctormayaskyoutoholdyourbreathforashortperiodduringthetesttopreventyourchestfrommovingupanddown.IfayoungchildneedsaCTscan,thedoctormayrecommendasedativetokeepthechildfrommoving.OncetheCTscanisover,theimagesaresenttoaradiologistforexamination.Aradiologistisadoctorwhospecializesindiagnosingandtreatingconditionsusingimagingtechniques,suchasCTscansandX-rays.Yourdoctorwillfollow-upwithyoutoexplaintheresults.WhatAretheRisksAssociatedwithaCTScan?ThereareveryfewrisksassociatedwithaCTscan.ThoughCTscansexposeyoutomoreradiationthantypicalX-rays,theriskofcancercausedbyradiationisverysmallifyouonlyhaveonescan.YourriskforcancermayincreaseovertimeifyouhavemultipleX-raysorCTscans.TheriskofcancerisincreasedinchildrenreceivingCTscans,especiallytothechestandabdomen.Somepeoplehaveanallergicreactiontothecontrastmaterial.Mostcontrastmaterialcontainsiodine,soifyou’vehadanadversereactiontoiodineinthepast,makesuretonotifyyourdoctor.Yourdoctormaygiveyouallergymedicationorsteroidstocounteractanypotentialsideeffectsifyou’reallergictoiodinebutmustbegivencontrast.It’salsoimportanttotellyourdoctorifyou’repregnant.ThoughtheradiationfromaCTscanisunlikelytoharmyourbaby,yourdoctormayrecommendanotherexam,suchasanultrasoundorMRIscan,tominimizerisk.WhatDoCTScanResultsMean?CTscanresultsareconsiderednormaliftheradiologistdidn’tseeanytumors,bloodclots,fractures,orotherabnormalitiesintheimages.IfanyabnormalitiesaredetectedduringtheCTscan,youmayneedfurthertestsortreatments,dependingonthetypeofabnormalityfound.LastmedicallyreviewedonFebruary25,2016MedicallyreviewedbyWilliamMorrison,M.D.—WrittenbyHeatherRoss—UpdatedonDecember19,2017ReadthisnextCranialCTScanMedicallyreviewedbyDeborahWeatherspoon,Ph.D.,R.N.,CRNAAcranialCTscanoftheheadisadiagnostictoolusedtocreatedetailedpicturesoftheskull,brain,paranasalsinuses,andeyesockets.READMORECTScanvs.MRIMedicallyreviewedbyJ.KeithFisher,M.DBothCTscansandMRIsarediagnostictoolsusedtocaptureinternalimagesofyourbody.Whataretheimportantdifferences?Whywouldyourdoctor…READMOREAllAboutGalliumScansMedicallyreviewedbyAlanaBiggers,M.D.,MPHAgalliumscanisadiagnostictestthatlooksforinfection,inflammation,andtumors.Galliumisradioactive,buttheriskofradiationexposure…READMORECervicalSpineCTScanMedicallyreviewedbyWilliamMorrison,M.D.AcervicalspineCTscanusesX-raysandcomputerimagingtocreateavisualmodelofyourcervicalspine.Weexplaintheprocedureanditsuses.READMOREWhatIsaPositronEmissionTomography(PET)Scan?Apositronemissiontomography(PET)scanisanimagingtestthatusesaspecialdyewithradioactivetracers.Learnwhyit’sperformedandhowto…READMOREC-ReactiveProteinTestC-reactiveproteinisproducedbytheliverinresponsetoinflammation.AC-reactiveproteintest,orCRPtest,measurestheamountofCRPinyour…READMOREErythrocyteSedimentationRateTest(ESRTest)MedicallyreviewedbyMeredithGoodwin,MD,FAAFPAnESR(erythrocytesedimentationratetest)isabloodtestthathelpsdetectinflammationfromautoimmunediseases,infection,cancer,andmore.READMOREMRIvs.X-Ray:WhatYouNeedtoKnowMedicallyreviewedbyAngelicaBalingit,MDLearntheinsandoutsofMRIvs.X-rayimagingtests,includingtheprosandconsofeachtest,howtheycomparetoCTscans,howmuchtheycost,and…READMOREParacentesis(AbdominalTap)MedicallyreviewedbyAlanaBiggers,M.D.,MPHParacentesisisaproceduretoremoveexcessfluidfromtheabdominalcavity.Thisfluidbuildupiscalledascites.Learnaboutpreparation,recovery…READMORE