TheDiaphragmaticCruraandRetrocruralSpaceNormalImagingAppearance,Variants,andPathologicConditionsGuoXiaochao2010.7.22RadioGraphics2008;28:1289-1305•Theretrocruralspace(RCS)isasmalltriangularregionwithinthemostinferiorposteriormediastinumborderedbythetwodiaphragmaticcrura.•MultiplanarimagingmodalitiesallowevaluationoftheRCSaspartofroutineexaminations.•Normalstructureswithintheretrocruralregionincludetheaorta,nerves,theazygosandhemiazygosveins,thecisternachyliwiththethoracicduct,fat,andlymphnodes.AnatomicConsiderations•DiaphragmandDiaphragmaticCrura•LymphNodes,CisternaChyli,andThoracicDuct52%atlymphangiography;1.7%atCT;15%–96%atMR•Aorta•AzygosandHemiazygosVeins•ParavertebralVenousPlexusvalveless•SympatheticTrunkandSplanchnicNerves•CisternaChyli&ThoracicDuct•ParavertebralVenousPlexus•CongenitaldiaphragmaticherniaBochdalekhernia(95%)Morgagni'shernia(2%)•Partialduplicationofthediaphragm•Discontinuityofthediaphragm•CongenitalAnomaliesoftheIVCAnatomicVariantsandAnomaliesAbnormalitiesoftheCrura•Lymphadenopathy•Neoplasms•ForegutMalformations•VascularDisorders•InfammatoryConditions•Infections•OtherAbnormalitiesAbnormalitiesoftheRCS•Lymphadenopathy(6mm)•NeoplasmsThesecanbecategorizedaccordingtotheircelloforiginintoneurogenic,mesenchymal,germcell,andlymphoidtumors.Neurogenictumorsganglioncelltumorsnervesheathtumorsparaganglia•VascularDisordersInfammatoryConditions•Retroperitonealfbrosis•Steroid-inducedretrocrurallipomatosis•Spondylosisdeformans•PancreaticpseudocystsInfections•Diabetes,immunosuppression,intravenousdrugabuse,anemia,andurinarytractinfectionsConclusions•DespitethesmallareathatencompassestheRCS,thereisawidevarietyofpathologicconditionswithinthisregion,whichislocatedattheposteriorconfnesoftheinferiorthoraxandupperabdomen.•Anunderstandingoftheanatomy,thenormalvariants,andthemultiplepathologicconditionsaffectingthediaphragmaticcruraandretrocruralstructuresfacilitatesthediagnosisofdisease.
