Fig. 5.

Radiography image, gray-level histogram, and tridimensional surface plot of COVID-19 patients stratified by the radiomic biomarker f287: (a) 67-year-old woman with bilateral consolidation and 13 days of survival (no occurrence of an event of death on follow-up), classified as a lower-risk case by the biomarker; (b) 36-year-old man with scattered consolidation and nine days of survival until death, classified as a higher-risk case by the biomarker. Although both cases look visually very similar, as described by radiological assessment and gray-level distributions, the higher-order radiomic biomarker could stratify the risk of the patient according to spectral properties of the radiographic image