title: High-resolution CT predictors of hypersensitivity pneumonitis.
abstract: BACKGROUND
  The purpose of this study was to evaluate the use of high-resolution chest computed tomography (HRCT) to distinguish hypersensitivity pneumonitis (HP) from other diffuse parenchymal lung diseases (DPLDs).
  
  
  METHODS
  We examined 130 consecutive patients admitted to our hospital with DPLDs proved by HRCT. Patients underwent clinical and paraclinical examinations. Two readers interpreted 111 HRCT scans using predefined criteria.
  
  
  RESULTS
  The findings in patients with HP were compared to those with other DPLDs (non-HP) by univariate and multivariate analyses. Five independent radiological predictors were identified and were given a weight according to their regression coefficient: ground-glass attenuation nodules (4 points), homogeneous ground-glass opacity (3 points), patchy ground-glass opacity (2 points), absence of adenopathy (2 points), and absence of linear/reticular patterns (2 points). A total score (that we called "diagnostic index") of 5 offered the best trade-off between sensitivity and specificity. At this point of the ROC curve, the sensitivity, specificity, and likelihood ratio were 74%, 90% and 7.7, respectively. Given a pre-test probability of HP of 34% (i.e., 38 HP / 111 patients), the post-test probability was 79%.
  
  
  CONCLUSIONS
  Our results provide evidence that HRCT can accurately distinguish HP from other DPLDs.
authors.affiliation: Centre Hospitalier Régional Universitaire de Besançon. gilles.rival@yahoo.fr.
authors.forename: Gilles
authors.initials: G
authors.lastname: Rival
authors.forename: Philippe
authors.initials: P
authors.lastname: Manzoni
authors.forename: Yves
authors.initials: Y
authors.lastname: Lacasse
authors.forename: Jean Charles
authors.initials: JC
authors.lastname: Polio
authors.forename: Virginie
authors.initials: V
authors.lastname: Westeel
authors.forename: André
authors.initials: A
authors.lastname: Dubiez
authors.forename: Thibaud
authors.initials: T
authors.lastname: Soumagne
authors.forename: François
authors.initials: F
authors.lastname: Laurent
authors.forename: Jean Charles
authors.initials: JC
authors.lastname: Dalphin
mesh_terms: D000542:Alveolitis, Extrinsic Allergic / Q000000981:diagnostic imaging*; D019540:Area Under Curve; D016009:Chi-Square Distribution; D003937:Diagnosis, Differential; D005602:France; D006801:Humans; D016015:Logistic Models; D008168:Lung / Q000000981:diagnostic imaging*; D015999:Multivariate Analysis; D015588:Observer Variation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed
keywords: HRCT; diagnostic procedures; hypersensitivity pneumonitis