title: Computed tomographic features of idiopathic fibrosing interstitial pneumonia: comparison with pulmonary fibrosis related to collagen vascular disease.
abstract: OBJECTIVE
  To compare the computed tomographic (CT) features of idiopathic fibrosing interstitial pneumonia with those of pulmonary fibrosis related to collagen vascular disease (CVD).
  
  
  METHODS
  We reviewed the CT scans of 177 patients with diffuse interstitial pulmonary fibrosis, of which 97 had idiopathic fibrosing interstitial pneumonia and 80 had CVD. The CT images were systematically scored for the presence and extent of pulmonary and extrapulmonary abnormalities. Computed tomographic diagnosis of usual interstitial pneumonia (UIP) or nonspecific interstitial pneumonia (NSIP) was assigned.
  
  
  RESULTS
  A CT pattern of UIP was identified in 59 (60.8%) of patients with idiopathic fibrosing interstitial pneumonia compared with 15 (18.7%) of those patients with CVD; conversely, the CT diagnosis of NSIP was made in 51 (64%) of patients with CVD compared with 36 (37%) of patients with idiopathic disease (P < 0.01). In 113 patients who had lung biopsy, the CT diagnoses of UIP and NSIP were concordant with the histologic diagnoses in 36 of 50 patients and 34 of 41 patients, respectively. Pleural effusions, esophageal dilation, and pericardial abnormalities were more frequent in patients with CVD than in patients with idiopathic fibrosing interstitial pneumonia.
  
  
  CONCLUSIONS
  Compared with patients with CVD, those patients with an idiopathic fibrosing interstitial pneumonia showed a higher prevalence of a UIP pattern and lower prevalence of an NSIP pattern as determined by CT. Identification of coexisting extrapulmonary abnormalities on CT can support a diagnosis of CVD.
authors.affiliation: Department of Radiology, National Jewish Medical and Research Center, Denver, CO 80206, USA.
authors.forename: Jeong-Hwa
authors.initials: JH
authors.lastname: Hwang
authors.forename: Shigeki
authors.initials: S
authors.lastname: Misumi
authors.forename: Hakan
authors.initials: H
authors.lastname: Sahin
authors.forename: Kevin K
authors.initials: KK
authors.lastname: Brown
authors.forename: John D
authors.initials: JD
authors.lastname: Newell
authors.forename: David A
authors.initials: DA
authors.lastname: Lynch
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003095:Collagen Diseases / Q000000981:diagnostic imaging* / Q000209:etiology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000150:complications* / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014652:Vascular Diseases / Q000000981:diagnostic imaging* / Q000209:etiology*