exposure reproducibilitymA linearity formulamAs linearityx ray timer accuracy testExposure reproducibilityma linearity testwhy is a step system and step chart needed for producing quality radiographsexposure reproducibility quizlet8 penny testExposure reproducibility QuizletExposure reproducibility definitionExposure reproducibility must be accurate to withinExposure linearityx ray qa testing

Reproducibility - Quality control in radiography

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Exposures made at the same kVp and mA stations of the same phantom thickness should produce the same optical density on the resulting image.   Qualitycontrolinradiography About ClusterOne HalfValueLayer EICalibration VisualInspection Film/ScreenContact GridAlignment CRErasure ClusterTwo LightFieldCongruencyTest TimerAccuracy kVpAccuracy LimitingSpatialResolution CRUniformity DR(QAP) ClusterThree Reproducibility ThresholdContrastDetailDetectabilityCR&DR CRDarkNoise Linearity Mammography Contact Qualitycontrolinradiography Reproducibility 3/12/2015 0Comments   DIANNEGUIANG1204474ExposuresmadeatthesamekVpandmAstationsofthesamephantomthicknessshouldproducethesameopticaldensityontheresultingimage.Thisisreferredtoasreproducibility(Papp,2011,p.107).Thisspeakstothefactthattheradiationintensityproducedbythex-raytubeshouldbethesamegiventhesametechniquesetting. Insteadoflookingattheopticaldensitiesofimages,analternatemethodthatcanbeperformedtoexaminereproducibilityiswiththeuseofanexposuremeter,alsoknownasadosimeter;thiswasthechosenmethodforthelabthatwasperformedinx-rayroom4intheB114laboftheInstituteofAppliedHealthSciencesbuilding.Theprocessinvolvedmaking10separateexposuresoftheexposuremeterat100cmSIDwiththetechnicalfactorssetat60kVpand5mAs.Inbetweeneachexposure,factorsettingswerechangedtoprovidedifferentcombinationsof5mAs;thiscanbeseeninTable1below. Table1.Thistableshowsthe10separateexposuresmadeandtheirresultantexposuremeterreading.Toabletoestablishwhetherthereproducibilityforthex-rayunitinroom4iswithinacceptablelimits,thereproducibilitycoefficientofvariationwasfirstdeterminedusingtheequation: Calculation:C=1/0.0172{[(0.017-0.0172)^2*8+(0.018-0.0172)^2*2]/(10-1)}^1/2C=0.02451 Meanvalueofexposuremeasurementcomparedtoeachexposurereading:(0.017-0.172)/0.0172=-1.16% (0.018-0.0172)/0.0172=4.65%AccordingtoSafetyCode35(S.C.35),thecoefficientofvariationofanytenconsecutiveradiationirradiationmeasurements,shouldbenogreaterthan0.05,andeachofthetenirradiationmeasurementsshouldbewithin15%ofthemeanvalueofthetenmeasurements.Ontheotherhand,theHealingArtsRadiationProtectionAct(H.A.R.P)statesthat thecoefficientofvariationofanytenconsecutiveradiationirradiationmeasurements,shouldbenogreaterthan0.08,andeachofthetenirradiationmeasurementsshouldbewithin20%ofthemeanvalueofthetenmeasurements.Sincetherecordedvaluesfromtheperformedlabresultedinacoefficientvariationof0.02451,itcanbeconcludedthatthex-rayunitinroom4iswithinacceptablelimits.Also,ascalculatedabove, eachofthetenirradiationmeasurementsarewellwithin15%and20%of themeanvalueofthetenmeasurements;thex-rayunitalsopassesthiscriteria. AccordingtoS.C.35,thereproducibilitytestforanx-rayunitshouldbeperformedannually.Itisimportantmakesurethatthereproducibilityforanx-rayunitiswithinacceptablelimitstoensurethatthesameresultswillbeobtainedwhenthesametechnicalfactorsareselected.Thisway,ifatechnologistwishestoreproduceagoodqualityimage,theycanbeconfidentthatthesametechniquesettingwillproducethesameresult.Thiswouldtheneliminatetheneedforarepeatx-raywhichreducespatientdose. REFERENCESHealthCanada.(2008). Safetycode35:Safetyproceduresfortheinstallation,useand      controlofx-rayequipmentinlargemedicalradiologicalfacilities.      Retrieved fromhttp://www.hc-sc.gc.ca.ServiceOntario.(2011). HealingArtsRadiationProtectionAct.      Retrieved from http://www.e-laws.gov.on.ca/html/regs/english/elaws_regs_900543_e.htm.Papp,J.(2011). QualityManagementintheImagingScience     (4thed.). St.Louis,MO:ElsevierMosby. 0Comments LeaveaReply. Poweredby Createyourownuniquewebsitewithcustomizabletemplates. GetStarted

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