CT Chest Severity Score for COVID 19 Pneumonia: A Quantitative Imaging Tool for Severity Assessment of Disease

To determine a cut-off value of Chest CT severity score (CT-SS) in order to discriminate between the clinical types of COVID-19 pneumonia. Observational study. Department of Radiology, Shifa International Hospital, from 1st March to June 30th, 2020. One hundred and three consecutive patients' RT PCR positive for COVID-19 were included. Two consultant radiologists, with experience of 7 to 10 years in body imaging, evaluated their HRCT studies in consensus and calculated the CT severity score. A scoring of all 20 individual regions in each lung were assigned by the radiologists attributing a score of 0, 1 or 2 to each region, if parenchymal opacification was none, less than 50%, or 50% or more, respectively. The CT severity score was a summation of scores of all 20 regions of both lungs combined with a range of 0 to 40 points. The scores were compared for clinically mild and severe disease. Significant differences were noted regarding the scoring of lung opacity in mild and severe groups in each lung segment, p