Questions and Answers Updated
2026
FactorsAcontrollingAimageAappearance:A-AAnswerA-artifacts
-windowing
-noise
-resolution
ArtifactA-AAnswerA-
AaAdistortionAorAerrorAinAanAimageAthatAisAunrelatedAtoAtheAsubjectAbeingAstudied
-
CTAimageAartifactAisAanyAdiscrepancyAbetweenAtheAreconstructedACTAnumbersAinAtheAimageAa
ndAtrueAattenuationAcoefficientsAofAtheAobjectA
-artifactsAdegradeAimageAqualityAandAcanAcauseAmisdiagnosisA
-classifiedAaccordingAtoAappearanceA&Acause
StreakAArtifactA-AAnswerA-appearAasAstraightAlinesAacrossAtheAimageA
-causedAby:A
*improperAsamplingAofAdata
*unevenAx-rayAbeam
*noise
*patientAmotion
RingAorABandAArtifactsA-AAnswerA-
areAproducedAwhenAtheAprojectionAreadingsAofAaAdetector(s)Ais/areAdefectiveA
-foundAinA3rdAgenerationACTAscanners
, ShadingAArtifactsA-AAnswerA-appearAnearAobjectsAofAhighAdensitiesA
-causedAbyAbeamAhardeningA(sameAenergy)
-differentialAabsorption=Atissue
*attenuatesAtheAx-rayAbeamAdifferentlyA
*atomicA#AofAtissueA(boneAisAhigher)
*pathology
*thickness
BeamAHardeningAArtifactA-AAnswerA-
createsAanAartifactAbecauseAtheAbeamAisAnotAuniform.AThereAisAlessAbeamAhardeningAatAtheA
edgesAofAanAobjectAthanAtheAcenterAwhichAisAreflectedAbyAtheACTAnumbersAassignedA
-isAmaterialAdependent.ADenseAboneAandAcontrastAagentsAresultAinAdarkAshadingAartifacts
-correctedAbyApolynomialAmapping
PatientAMotionAArtifactA-AAnswerA-voluntaryAorAinvoluntaryA
-
appearsAasAstreaksAbecauseAtheAinabilityAofAtheAreconstructionAalgorithmAtoAdealAwithAtheAd
ataAinconsistenciesA
-methodAtoAreduceAmotionA
*immobilization
*properAbreathingAinstructions
*shortAscanAtimes
MetalAArtifactsA-AAnswerA-
areAcausedAbyAtheApresenceAofAtheAmetalAobjectsAinAtheApatient.AEx.AprostheticAdevices,Adent
alAfillings,AsurgicalAclips