COVID-19 Research Paper Volume 13, Issue 7 pp 9186—9224

A COVID-19 risk score combining chest CT radiomics and clinical characteristics to differentiate COVID-19 pneumonia from other viral pneumonias


Figure 2. The patient-based COVID-19 risk scores demonstrated by nomograms. (A) The risk score using radiomic features only. (B) The risk score using clinical factors only. (C) The risk score combining radiomic features and clinical factors. GLRLM_LRLGE_(25, 90) represents the radiomic feature long run low gray-level emphasis, which describes the distribution of the long homogeneous runs with low gray-levels within the image. The numbers in the bracket represents the parameters used to calculate that particular radiomic feature. The parameters of 25 and 90 in GLRLM_LRLGE represent the binary mask in 2.5D and 90 degrees, which describes that the GLRLM was computed in 2D slice by slice; then, the occurrence of run length from 90 degrees from all 2D image slices was summed. ID_Global_max represents the radiomic feature intensity direct global max, which describes that the binary mask was preprocessed for the features derived directly from the image intensity. The binary mask in ID_Global_max can be modified through intensity thresholding, by binary erosion, and using only the binary slice with the maximum area. The unit for lactate dehydrogenase is U/L. The unit for creatine kinase isoenzymes is μg/L. Supplementary Appendix 2 explains how to use the nomograms.