Concordance of High-Resolution Ct Pattern Classification with Multidisciplinary Diagnosis in Suspected Interstitial Lung Disease: A Retrospective Study

Abstract

Background: Interstitial lung diseases (ILDs) are a heterogeneous group of diffuse parenchymal lung disorders with variable inflammatory and fibrotic components. Overlapping clinical and radiological features make diagnosis challenging, and high-resolution computed tomography (HRCT) is central to the imaging assessment of suspected ILD.Objective: To describe the distribution of HRCT patterns in patients with suspected ILD and to assess their concordance with the final multidisciplinary discussion (MDD) diagnosis.Methods: This retrospective single-centre study included 52 patients with suspected ILD who underwent HRCT between January 2023 and June 2023. Two thoracic radiologists independently classified HRCT patterns using the 2018 ATS/ERS/JRS/ALAT framework. Concordance with the final MDD diagnosis was calculated as a proportion with 95% confidence intervals (CIs), and interobserver agreement was assessed with Cohen's kappa.Results: The mean age was 61.8 ± 12.3 years, and 30 patients (57.7%) were male. Definite usual interstitial pneumonia (UIP) was the most frequent HRCT pattern (20 patients, 38.5%), followed by nonspecific interstitial pneumonia (NSIP; 12, 23.1%), hypersensitivity pneumonitis (HP; 6, 11.5%), organizing pneumonia (OP; 6, 11.5%), sarcoidosis (5, 9.6%), and other patterns (3, 5.8%). Overall HRCT–MDD concordance was 82.7% (43/52; 95% CI 70.3–90.6%), including 95.0% (19/20; 95% CI 76.4–99.1%) for definite UIP and 75.0% (24/32; 95% CI 57.9–86.7%) for non-UIP patterns. Interobserver agreement was κ = 0.79 (95% CI 0.68–0.90). Nine cases (17.3%) were discordant.Conclusion: HRCT pattern classification showed 82.7% concordance with the final MDD diagnosis, with higher concordance for definite UIP than for non-UIP patterns. Because MDD incorporates imaging, these results describe agreement rather than independent diagnostic accuracy. HRCT should be interpreted within an integrated clinical and multidisciplinary assessment.