Quantitative Volumetric CT Analysis of COVID-19 Pneumonia and Correlation with Neutrophillymphocyte Ratio

Abstract

Objective:Although scientific community has various knowledge about coronavirus pandemic, further studies are needed about its nature. The aim of our study is to explore the relationship between the imaging and laboratory findings of Coronavirus disease-2019 (COVID-19).Method:Our study is a retrospective single-center study on patients with COVID-19. Patients with chest computed tomography and with positive reverse-transcription polymerase chain reaction test results were examined. Total lung volume and lesion volume were calculated semi-automatically by Osirix software. Interclass correlation coefficient was used for testing consistency between the observers. Patients were divided into three groups as mild, moderate, and severe considering the involved lung volume. The relationship between laboratory findings and radiological severity investigated with area under the curve in receiver operating characteristic plot.Results:One hundred and six patients were included (female: 44, male: 62) in this study and the median age was 55 years. The most common radiologic features were peripheral, multifocal, ground glass opacities with sub-pleural and basal distribution. A positive and moderate correlation was found between the percentage of involvement and the neutrophil to lymphocyte ratio (N/L) (rho=0.635, p<0.001), which was the most correlated laboratory feature with radiological severity. The cut-off value was 1.1195 for N/L ratio (95.5% sensitivity, 85.7% specificity, 0.845 area under the curve, 0.742-0.948 95% confidence interval).Conclusion:The percentage of involvement can be used as a predictor to decide the severity of the disease in patients, who are thought to have COVID-19 pneumonia.

Keywords

• computed tomography
• covid-19
• neutrophil to lymphocyte ratio