COVID-19: HRCT lung pattern, distribution and severity score with clinico-pathological correlation in a tertiary level institution in rural Maharashtra

Abstract

Background: The severe acute respiratory syndrome corona viruses 2 (SARSCoV-2) are enveloped positive sense RNA virus. Most patients of coronavirus disease 2019 (COVID-19) show fever, cough, dyspnoea and myalgia with weakness.Methods: In this retrospective cross-sectional study 502 patients who were RT-PCR positive for COVID-19 participated in our study after informed consent was taken from all patients, during the period of 3 months between July to September 2020. The study was conducted in Department of Radiodiagnosis at Krishna Institute of Medical Sciences in karad. Each HRCT-Lung scan was evaluated for distribution (central or peripheral); findings (like ground glass opacities, interlobular septal thickening). Every lobe was then allotted CT severity score.Results: The threshold cut-off value for HRCT severity score was found to be 8. The parameters achieved with this cut-off value were: sensitivity – 100%, specificity- 95.15%, positive predictive value- 85.7%, negative predictive value – 100%. On application of pearson correlation coefficient between HRCT severity score and pathological parameters, it was found that strongest correlation was found to be with D-dimer values (0.833), then with ESR (0.484) and least with N/L (neutrophil/lymphocyte) ratio (0.350).Conclusions: On imaging, HTCT thorax showed most common involvement to be peripheral, ground glass opacity and crazy paving being most common findings. The most common finding being left and right lower lobe. The ROC curve showed the CT severity score corresponding to clinical severity to be 8. Among pathological parameters, the strongest correlation with CT severity score was found to be with D-dimer.