title: Rheumatoid arthritis-associated interstitial lung disease: radiologic identification of usual interstitial pneumonia pattern.
abstract: OBJECTIVE
  To determine the accuracy of computed tomography (CT) in identifying the histopathologic usual interstitial pneumonia (UIP) pattern in rheumatoid arthritis-associated interstitial lung disease (RA-ILD).
  
  
  METHODS
  All patients were enrolled into institutional review board-approved longitudinal cohorts at their respective institution, and informed consent was obtained at the time of enrollment. Images of patients with surgical lung biopsy-proved RA-ILD (n = 69) were collected from three tertiary care centers. Two experienced thoracic radiologists independently reviewed the CT scans. The CT pattern was categorized as definite UIP, possible UIP, or inconsistent with UIP in accordance with published criteria. Findings of biopsies were reviewed by an experienced lung pathologist. The sensitivity and specificity of definite CT UIP pattern to histopathologic UIP pattern were determined. The agreement between radiologists was assessed by calculating a κ score.
  
  
  RESULTS
  The histopathologic UIP pattern was present in 42 of 69 (61%) patients. Men were more likely than women to have a histopathologic UIP pattern (P = .02). Twenty patients (29%, 20 of 69) had a definite UIP pattern on CT scans. The specificity of CT UIP pattern was 96% (26 of 27; 95% confidence interval [CI]: 81%, 100%), with a negative predictive value of 53% (26 of 49). The sensitivity of CT UIP pattern was 45% (19 of 42; 95% CI: 30%, 61%), with a positive predictive value of 95% (19 of 20). The agreement between radiologists for definite UIP pattern versus not was 87% (κ = 0.67, P < .0001).
  
  
  CONCLUSIONS
  Definite UIP pattern on a CT scan in RA-ILD is highly specific and moderately sensitive for histopathologic UIP pattern. CT can therefore help accurately identify the UIP pattern in RA-ILD.
authors.affiliation: From the Departments of Medicine (D.A., T.E.K., H.R.C., J.S.L.) and Radiology (B.M.E., T.H.U.), University of California, San Francisco, Calif; Department of Laboratory Medicine and Pathology, Mayo Clinic, Phoenix, Ariz (T.V.C.); Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan, 388-1 Pungnap-2dong, Songpa-gu, Seoul 138-736, Korea (B.H.K., D.S.K.); and Department of Medicine, Mayo Clinic, Rochester, Minn (J.H.R.).
authors.forename: Deborah
authors.initials: D
authors.lastname: Assayag
authors.forename: Brett M
authors.initials: BM
authors.lastname: Elicker
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Urbania
authors.forename: Thomas V
authors.initials: TV
authors.lastname: Colby
authors.forename: Bo Hyoung
authors.initials: BH
authors.lastname: Kang
authors.forename: Jay H
authors.initials: JH
authors.lastname: Ryu
authors.forename: Talmadge E
authors.initials: TE
authors.lastname: King
authors.forename: Harold R
authors.initials: HR
authors.lastname: Collard
authors.forename: Dong Soon
authors.initials: DS
authors.lastname: Kim
authors.forename: Joyce S
authors.initials: JS
authors.lastname: Lee
mesh_terms: D001172:Arthritis, Rheumatoid / Q000150:complications*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D017563:Lung Diseases, Interstitial / Q000000981:diagnostic imaging* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*