Figure 3b. Serial radiographic changes in a 45-year-old man with SARS with initial category III and maximal category VI distribution of SARS-related lesions. (a) Frontal chest radiograph obtained 2 days after fever onset shows air-space opacities involving less than one-third of the bilateral middle and left upper lung zones (arrows) (category III, extent score of 3). (b) Follow-up chest radiograph obtained 3 days later shows marked progression of the SARS-related opacities (arrows) in both lungs, involving more than two-thirds of the bilateral middle lung, less than two-thirds of the bilateral upper lung, and less than one-third of the bilateral lower lung. (category VI, extent score of 12). The patient died 6 days later.