ROC curves for the PVR, CT score, CRP, and LDH.

ROC curve for a. PVR using Z2 (≥–600 HU) and b. CT scores using Z2 (≥–600 HU), c. CRP, and d. LDH. CRP, C-reactive protein; CT, computed tomography; LDH, lactate dehydrogenase; PVR, pneumonia volume ratio; ROC, receiver operating characteristic; SD, standard deviation; Z2, Ziostation2.