DIAGNOSTIC ACCURACY OF X-RAY CHEST IN INTERSTITIAL LUNG DISEASE AS CONFIRMED BY HIGH RESOLUTION COMPUTED TOMOGRAPHY (HRCT) CHEST

Objective: To determine the diagnostic accuracy of x-ray chest in interstitial lung disease as confirmed by high resolution computed tomography (HRCT) chest. Study Design: A cross-sectional validational study. Place and Duration of Study: Department of Diagnostic Radiology, Combined Military Hospital Rawalpindi, from Oct 2013 to Apr 2014. Material and Method: A total of 137 patients with clinical suspicion of interstitial lung disease (ILD) aged 20-50 years of both genders were included in the study. Patients with h/o previous histopathological diagnosis, already taking treatment and pregnant females were excluded. All the patients had chest x-ray and then HRCT. The x-ray and HRCT findings were recorded as presence or absence of the ILD. Results: Mean age was 40.21 ± 4.29 years. Out of 137 patients, 79 (57.66%) were males and 58 (42.34%) were females with male to female ratio of 1.36:1. Chest x-ray detected ILD in 80 (58.39%) patients, out of which, 72 (true positive) had ILD and 8 (false positive) had no ILD on HRCT. Overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of chest x-ray in diagnosing ILD was 80.0%, 82.98%, 90.0%, 68.42% and 81.02% respectively. Conclusion: This study concluded that chest x-ray is simple, non-invasive, economical and readily available alternative to HRCT with an acceptable diagnostic accuracy of 81% in the diagnosis of ILD. ,