Journal of Clinical and Diagnostic Research. 2022 Apr, Vol-16(4): OC24-OC27 24 24 DOI: 10.7860/JCDR/2022/53224.16242 Original Article Internal Medicine Section Predictive Role of Chest Radiograph in COVID-19 Hospitalised Patients- A Retrospective Analysis INTRODUCTION Chest imaging remains the primary modality that is used in the management of patients with infections causing lung involvement. A consensus statement was issued by the Fleischner Society exploring Computed Tomography (CT) of the chest as a prime imaging modality in the diagnosis, risk stratification and management of the Coronavirus Disease 2019 (COVID-19) patients [1], but many professional organisations in the developing world face issues such as non availability of CT. Also, owing to the rapid spread of infection, tests that are less time consuming and can be done quickly, should be adopted. To handle such situations, the Society of Thoracic Radiology and American College of Radiology have suggested the use of portable Chest Radiograph (CXR) to combat this crisis [2]. The CXR has been shown to have a low sensitivity of 69%, in diagnosing COVID-19 lung involvement [3]. Studies among the severe acute respiratory syndromes observed in 2003 and other pneumonia causing infections, reported a positive correlation between poorer clinical outcomes and two or more zones involvement on CXRs [4,5]. However, pre-existing heart or lung conditions of the individuals and observer expertise influence the CXR interpretation. The CXR characteristics of COVID-19 infection, have been focused in few studies from countries like Italy and China. Peripheral ground glass opacities or consolidation noted in the lower and mid zones were the most predominant CXR findings observed [3,6]. The CXR in COVID-19 infected patients had variable sensitivity reported, with one study quoting sensitivity as high as 89% [7]. The CXR severity was worser with advancing age, non survivors [8-10], and more likely for intubation and mechanical ventilation [11,12]. CXR is the primary imaging modality adopted for the diagnosis and risk stratification of COVID-19 infection in the UK. The British society of Thoracic Imaging (BSTI) have recommended the use of severity grading in CXR as mild/moderate/severe in suspected COVID-19 infection, though no clear guidance exists on the constitutes of each severity grade [13]. Other CXR grading systems have been used are the Radiographic Assessment of Lung Oedema (RALE) score, where the lungs are split into quadrants, and the involvement and density are scored, the quadrant scores are multiplied and then summed and is a 0-48 score [14], a simplified version of the RALE score, where each lung is given a score of 0-4 proportional to the amount of lung affected has also been tried [3]. Brixia score, is yet another CXR score [9,10], which is scored 0-18, where the left and right upper, middle and lower zones are each given a 0-3 score proportional to the lung involvement. Toussie D et al., utilised a scoring system based on the number of lung zones involved in CXR. Lung fields on CXR were divided into six zones, three on each lung. A score of 2 or more correlated with need JUDAH NIJAS ARUL 1 , MOHAN KUMAR 2 , SWATHY MOORTHY 3 , RAJKUMAR MANI 4 Keywords: Coronavirus disease, Disease severity, Portable chest radiograph, Radiograph score ABSTRACT Introduction: The portable Chest Radiograph (CXR) has an indispensable role in large scale screening and diagnosis of Coronavirus Disease 2019 (COVID-19), especially in developing countries with limited resources. It can help in predicting the severity of lung involvement in the patients infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, especially in areas where the Computed Tomography (CT) is unavailable. Aim: To determine the prognostic value of CXR at clinical presentation in assessing the disease severity and its correlation with inflammatory markers in COVID-19 hospitalised patients. Materials and Methods: This was a single-centre retrospective study, conducted at Sri Ramachandra Institute of Higher Education and Research, from October 2020 to December 2020, on hospitalised COVID-19 patients. Clinically, the patients were categorised as mild, moderate and severe, based on their peripheral oxygen saturation- more than 94%, between 90-93% , and less than or equal to 89%, respectively. Blood samples, drawn at presentation to the hospital tested for various inflammatory markers proven to be predictive of disease severity, were documented for the analysis purpose. The CXRs, done at the presentation, were scored based on the number of zones involved and type of abnormality present (ground glassing, consolidation and septal thickening). The CXRs were scored a minimum ‘0’ to a maximum of ‘9’. Correlation between the radiograph score and inflammatory markers was further analysed. Results: Among the 456 study patients, 71% had mild, 15% had moderate and 14% had severe COVID-19 infection. The mean CXR score in each category was 1, 3 and 4, respectively (p-value <0.001). The study groups were grouped as mild and non mild (included the moderate and severe categories). A criterion CXR score of 2 was able to differentiate mild and non mild cases (sensitivity was 78.29%, specificity was 77.98%, positive predictive values was 58.38%, negative predictive values was 90.11%), with an accuracy of 78.1%. The inflammatory markers like Neutrophil Lymphocyte Ratio (NLR), Absolute Lymphocyte Counts (ALC), eosinophil%, D-dimer, Lactate Dehydrogenas (LDH), Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein (CRP), and ferritin showed statistically significant difference between the two groups (p-value<0.001). Conclusion: The CXR can be used as a screening and predictive tool for disease severity in developing countries where access to Computed Tomography (CT) is limited. Given the possibility of subsequent waves of the COVID-19 pandemic and the risk of excessive radiation exposure from CT, CXR may be used as a reliable alternative.