willgenerateartifactindifferentlocation,whereasatruedissectionwillbeconsistent.Reconstructionbyamulti-detectorrowCT(helicalCT)inasagittalviewwillalsogiveamoreaccurateassessmentofaorticartifact[12,13].Cardiacgatinghasbeenshowntoreducetheartifactattheaorticroot[14].However,inemergencycondition,itsapplicationhasnotyetbeenvalidated[12].Transesophagealechocardiogram(TEE)couldalsoassistinproperdiagnosis.ThesensitivityandspecificityofTEEhavebeenreportedtobeashighas98%and63%to96%,respectively[15].ThemainlimitationofTEEisitsstrongdependenceontheexperienceoftheinvestigator.Misseddiagnosisofaorticdissectionleadstoapoten-tiallylethaloutcome,whereasmisjudgmentofartificialimagesresultsinunnecessarythoracotomy.FamiliaritywiththesediagnosticpitfallsofCTfacilitatescorrectrecognitionofaorticdissection.Wen-ChuChiangMD,MPHPei-ChiehKaoMDChan-PingSuMDDepartmentofEmergencyMedicineNationalTaiwanUniversityHospital,Yun-LinBranchTaipei100,TaiwanE-maiaddress:drchiangl@ha.mc.ntu.edu.twJuanHsuMDDepartmentofCardiovascularSurgeryNationalTaiwanUniversityHospital,Yun-LinBranchTaipei100,Taiwandoi:10.1016/j.ajem.2006.04.011References[1]KlompasM.Doesthispatienthaveanacutethoracicaorticdissection?JAMA2002;287:2262-72.[2]KhanIA,NairCK.Clinical,diagnostic,andmanagementperspectivesofaorticdissection.Chest2002;122:311-28.[3]Traumaradiologymisread/over-readimagesandreviews.Availableat:http://www.trauma.org/radiology/index.html[accessedonMar30,2006].[4]HaganPG,NienaberCA,IsselbacherEM,etal.TheInternationalRegistryofAcuteAorticDissection(IRAD):newinsightsintoanolddisease.JAMA2000;283:897-903.[5]SpittellPC,SpittellJrJA,JoyceJW,etal.Clinicalfeaturesanddifferentialdiagnosisofaorticdissection:experiencewith236cases(1980through1990).MayoClinProc1993;68:642-51.[6]BickerstaffLK,PairoleroPC,HollierLH,etal.Thoracicaorticaneurysms:apopulation-basedstudy.Surgery1982;92:1103-8.[7]NienaberCA,von-KodolitschY,NicolasV,etal.Thediagnosisofthoracicdissectionbynoninvasiveimagingprocedures.NEnglJMed1993;328:1-9.[8]BatraP,BigoniB,ManningJ,etal.Radiographics2000;20:309-20.[9]DuvernoyO,CouldenR,YtterbergC.Aorticmotion:apotentialpitfallinCTimagingofdissectionintheascendingaorta.JComputAssistTomogr1995;19:569-72.[10]QanadliSD,HajjamM,MesurolleB,etal.MotionartifactsoftheaortasimulatingaorticdissectiononspiralCT.JComputAssistTomogr1999;23:1-6.[11]WheatMW.Acutedissectionoftheaorta.CardiovascClin1987;17:241-62.[12]WilloteauxS,LionsC,GaxotteV,etal.Imagingofaorticdissectionbyhelicalcomputedtomography(CT).EurRadiol2004;14:1999-2008.[13]KapustinAJ,LittHI.Diagnosticimagingforaorticdissection.SeminThoracCardiovascSurg2005;17:214-23.[14]Morgan-HughesGJ,OwensPE,MarshallAJ,etal.Thoracicaortaatmulti-detectorrowCT:motionartifactwithvariousreconstructionwindows.Radiology2003;228:583-8.[15]KerenA,KimCB,HuBS,etal.Accuracyofbiplaneandmultiplanetransesophagealechocardiographyindiagnosisoftypicalacuteaorticdissectionandintramuralhematoma.JAmCollCardiol1996;28:627-36.OthercausesofunilateralpulmonaryedemaTotheEditor,WereadwithinterestthearticlebUnilateralpulmonaryedemarelatedtomassivemitralinsufficiencyQwhereintheauthorsdescribetheoccurrenceofunilateralpulmonaryedemaaftermitralinsufficiency[1].Wedescribeacaseofunilateralpulmonaryedemarelatedtoend-stagerenaldiseasethatimprovedrapidlywithhemodialysisandreviewtheliteratureforthecausesofunilateralpulmonaryedema.A34...