Diagnostic Accuracy of Chest X-Ray in Interstitial Lung Diseases, Keeping High Resolution Computed Tomography Scan as Gold Standard

Abstract

OBJECTIVES

To determine the accuracy of the plain chest radiograph in diagnosing interstitial lung diseases (ILDs), keeping a high-resolution CT scan (HRCT) as the gold standard.

METHODOLOGY

A cross-sectional study was conducted. A total of 75 patients who visited the Department of Radiology department over two years were assessed by prospective analysis of their radiology reports. All the HRCTs and Chest X-ray images were reviewed. Data collected was recorded on a specially designed proforma and entered into Microsoft Excel and SPSS (Version 22.0. IBM Corp., Armonk, NY). Patients with a history of acute exacerbation of symptoms were excluded.

RESULTS
The median age of the patients was 59 years, with SD 12.2. Chest radiographs detected interstitial lung disease (ILD) in 42/75 (56%).). The chest radiograph’s sensitivity, specificity, Positive Predictive Value (PPV), and Negative Predictive Value (NPV) were 76%, 84%, 86.3% and 76.7%. A plain chest X-ray's positive likelihood ratio (LR+) was 4.75, while the negative likelihood ratio (LR-) was 0.28. The overall accuracy of CXR was calculated as 78.6%.

CONCLUSION

Our study concluded that chest X-ray is the ideal initial investigation for diagnosing Interstitial lung disease (ILDS) with an accuracy of 78.6% compared to HRCT.