Enlargedvestibularaqueduct(EVA),themostfrequentidentifiablecauseofcongenitalhearingloss,isevaluatedwithhigh-definitionmultidetectorCTintheaxialplane.OurpurposewastodeterminewhichreformattedCTmeasurementsaremostreproducible.Sevenmultiplanarreformattedimageswerecreatedforeachofthe64temporalbonesinpatientswithEVA.Intraclasscorrelationcoefficients(ICC)wereusedtoassessinter-observervariability,andbothlinearregressionandROCanalyseswereusedtocomparethemeasurementswithseverityofhearingloss,asassessedbypuretoneaudiometry.Allsevenmeasurementshadexcellentinter-observervariability,withaverage-measureICCrangingfrom0.92to0.98.Therewasnostatisticallysignificantcorrelationbetweentheradiologicdegreeofaqueductenlargementandseverityofhearinglossusinganyofthesevenmeasurements;ROCanalysesrevealedareasunderthecurvesrangingfrom0.57to0.73.Optimalaccuracywasobtainedwithathresholdof1.75mmasmeasuredattheaqueductalapertureintheP€oschlplane,withsensitivityof0.75andspecificityof0.63.AlthoughtheradiologicmeasurementmaynotserveasareliabletoolforassessingseverityofEVA,P€oschlplanereformattinghasproventobebetterthanconventionalaxialacquisitionplaneforidentifyingpatientswithclinicallysignificanthearingloss.
