title: CT analysis of the anterior mediastinum in idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia.
abstract: OBJECTIVE
  We wanted to determine whether the amount and shape of the anterior mediastinal fat in the patients suffering with usual interstitial pneumonia (UIP) or nonspecific interstitial pneumonia (NSIP) was different from those of the normal control group.
  
  
  METHODS
  We selected patients who suffered with UIP (n = 26) and NSIP (n = 26) who had undergone CT scans. Twenty-six controls were selected from individuals with normal CT findings and normal pulmonary function tests. All three groups (n = 78) were individually matched for age and gender. The amounts of anterior mediastinal fat, and the retrosternal anteroposterior (AP) and transverse dimensions of the anterior mediastinal fat were compared by one-way analysis of variance and Bonferroni's test. The shapes of the anterior mediastinum were compared using the Chi-square test. Exact logistic regression analysis and polychotomous logistic regression analysis were employed to assess whether the patients with NSIP or UIP had a tendency to show a convex shape of their anterior mediastinal fat.
  
  
  RESULTS
  The amount of anterior mediastinal fat was not different among the three groups (p = 0.175). For the UIP patients, the retrosternal AP dimension of the anterior mediastinal fat was shorter (p = 0.037) and the transverse dimension of the anterior mediastinal fat was longer (p = 0.001) than those of the normal control group. For the NSIP patients, only the transverse dimension was significantly longer than those of the normal control group (p < 0.001). The convex shape of the anterior mediastinum was predictive of NSIP (OR = 19.7, CI 3.32-infinity, p < 0.001) and UIP (OR = 24.42, CI 4.06-infinity, p < 0.001).
  
  
  CONCLUSIONS
  For UIP patients, the retrosternal AP and transverse dimensions are different from those of normal individuals, whereas the amounts of anterior mediastinal fat are similar. UIP and NSIP patients have a tendency to have a convex shape of their anterior mediastinal fat.
authors.affiliation: Department of Radiology and the Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea. rosaceci@radiol.snu.ac.kr
authors.forename: Chang Hyun
authors.initials: CH
authors.lastname: Lee
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Lee
authors.forename: Kyu Ri
authors.initials: KR
authors.lastname: Son
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Chun
authors.forename: Kun Young
authors.initials: KY
authors.lastname: Lim
authors.forename: Jin Mo
authors.initials: JM
authors.lastname: Goo
authors.forename: Jung-Gi
authors.initials: JG
authors.lastname: Im
authors.forename: Jeong Nam
authors.initials: JN
authors.lastname: Heo
authors.forename: Jae-Woo
authors.initials: JW
authors.lastname: Song
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D001823:Body Composition; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000000981:diagnostic imaging*; D008297:Male; D008477:Mediastinal Diseases / Q000000981:diagnostic imaging*; D008875:Middle Aged; D011658:Pulmonary Fibrosis / Q000000981:diagnostic imaging*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*