Significance of Using the Interstitial Lung Disease Reporting and Data System (ILD-RADS) in Diagnosis of ILDs ABSTRACT Background: A standardized template for reporting interstitial lung diseases (ILDs) at high-resolution computed tomography (HRCT) called the Interstitial Lung Disease Imaging Reporting and Data System (ILD-RADS) was recently introduced. Objective: The aim of the current work was to assess the significance of using the ILD-RADS in the diagnosis as well as categorization of ILDs at HRCT. Patients and methods: This retrospective cross-sectional study comprised 42 ILDs patients. All patients underwent multi-detector HRCT scans, which were reviewed and categorized according to the ILD RADS by an experienced radiologist. The final diagnoses of ILDs were determined by multidisciplinary diagnosis with transbronchial lung biopsy (n=4) or without lung biopsy (n=38). Results: The study included 18 males and 24 females, (with median age 57 years, and interquartile range=52-64 years). Based on the final diagnoses, cases were classified into two groups: cases with idiopathic pulmonary fibrosis (IPF) (n=8) and with non-IPF ILDs (n=38). The most commonly found HRCT pulmonary finding in all patients was pulmonary reticulations (n=42, 100%). The presence of honeycombing was significantly different between patients with IPF and those without IPF. (P=0.02). The detected extra-pulmonary findings did not differ significantly between IPF and non- IPF patients. 87.5% of IPF patients were assigned ILD-RADS-1 versus 23.5% of non-IPF patients (P=0.0008). 47.1% of the non-IPF patients were assigned ILD-RADS-4 versus none of the IPF patients (P=0.014). Conclusion: It could be concluded that using the ILD-RADS can help differentiate between IPF and non IPF ILDs at HRCT. Keywords: Interstitial Lung Disease Reporting and Data System (ILD-RADS); Idiopathic pulmonary fibrosis; High- Resolution Computed Tomography.