title: Fluid collection in the right lateral portion of the superior aortic recess mimicking a right mediastinal mass: assessment with chest posterior anterior and MDCT.
abstract: OBJECTIVE
  We observed patients in whom the fluid collection in the right lateral portion of the superior aortic recess on computed tomography (CT) scans mimicked a right anterior mediastinal mass on chest PA radiographs. The purpose of this study was to assess chest PA and CT features of these patients.
  
  
  METHODS
  All chest PA radiographs and CT scans in 9 patients were reviewed by two radiologists on a consensus basis; for the presence of pleural effusion, pulmonary edema and heart size on chest PA radiographs. For the portion of the fluid collection in the superior aortic recess (SAR), a connection between the right lateral portion of the SAR (rSAR) and posterior portion of the SAR (pSAR) on CT scans, and the distance between the right lateral margin of the rSAR and the right lateral margin of the superior vena cava.
  
  
  RESULTS
  Fluid collection in the rSAR on CT scans caused a right anterior mediastinal mass or a bulging contour on chest PA radiographs in all women patients. All patients showed cardiomegaly, five patients had pleural effusion, and two patients had mild pulmonary edema. Further, eight patients showed a connection between the rSAR and the pSAR.
  
  
  CONCLUSIONS
  The characteristic features of these patients are the right anterior mediastinal mass-like opacity due to fluid collection in the rSAR, are bulging contour with a smooth margin and cardiomegaly regardless of pulmonary edema on the chest PA radiographs, and fluid connection between the rSAR and the pSAR on CT scans.
authors.affiliation: Department of Radiology, Gangneung Asan Hospital, College of Medicine, University of Ulsan, Gangneung 210-711, Korea.
authors.forename: Dong Rock
authors.initials: DR
authors.lastname: Shin
authors.forename: Dae Shick
authors.initials: DS
authors.lastname: Ryu
authors.forename: Man Soo
authors.initials: MS
authors.lastname: Park
authors.forename: Seung Mun
authors.initials: SM
authors.lastname: Jung
authors.forename: Jae Hong
authors.initials: JH
authors.lastname: Ahn
authors.forename: Jong Hyeog
authors.initials: JH
authors.lastname: Lee
authors.forename: Soo-Jung
authors.initials: SJ
authors.lastname: Choi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging*; D006332:Cardiomegaly / Q000000981:diagnostic imaging; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008477:Mediastinal Diseases / Q000000981:diagnostic imaging*; D008875:Middle Aged; D010996:Pleural Effusion / Q000000981:diagnostic imaging*; D011654:Pulmonary Edema / Q000000981:diagnostic imaging*; D013902:Radiography, Thoracic / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media