<b>Diagnostic Accuracy of Chest Radiography in Diagnosing Interstitial Lung Diseases Keeping High Resolution Computed Tomography as a Gold Standard</b>

Background: Interstitial lung diseases (ILDs) encompass a heterogeneous group of diffuse parenchymal lung disorders characterized by inflammation and fibrosis, leading to significant morbidity and mortality. Accurate and early diagnosis is crucial for management, and while chest radiography remains widely used due to accessibility, high-resolution computed tomography (HRCT) is considered the gold standard for detecting characteristic ILD patterns. Objective: To evaluate the diagnostic accuracy of chest radiography in detecting ILD features, using HRCT as the reference standard, and to assess the sensitivity, specificity, and clinical utility of radiographic findings. Methods: This analytical cross-sectional study was conducted at DHQ Hospital Narowal over four months, enrolling 72 adult patients with suspected ILD. Participants underwent chest radiography and HRCT within 48 hours. Radiological features—including consolidation, bronchiectasis, honeycombing, nodular opacities, and pleural effusion—were interpreted by blinded radiologists. Sensitivity, specificity, and diagnostic accuracy of chest X-ray were calculated against HRCT findings. Results: Chest radiography showed variable sensitivity across ILD features: 63.2% for consolidation, 43.8% for honeycombing, 49.0% for bronchiectasis, 62.3% for nodular opacities, and 67.3% for pleural effusion. HRCT consistently demonstrated higher detection rates across all parameters (p < 0.05). Conclusion: While chest radiography offers preliminary diagnostic value, it lacks sufficient accuracy for definitive ILD diagnosis. HRCT remains indispensable for accurate assessment and clinical decision-making. Keywords: Interstitial Lung Disease, Chest Radiography, High-Resolution Computed Tomography, Diagnostic Accuracy, HRCT, Pulmonary Imaging.