High-resolution CT findings of severe acute respiratory syndrome at presentation and after admission.

OBJECTIVE: The aim of this study was to assess the high-resolution CT (HRCT) findings at presentation and after hospital admission in patients with severe acute respiratory syndrome (SARS).

MATERIALS AND METHODS: We reviewed the HRCT findings at presentation (n = 12) and after hospital admission (n = 25) of 29 patients with SARS and compared the HRCT findings with the radiographic findings. HRCT scans were obtained using 1-mm (n = 28) or 2-mm (n = 1) collimation. The radiographs and HRCT scans were reviewed independently by two observers who reached a decision by consensus.

RESULTS: All patients had abnormal findings on HRCT at presentation. Eight of these 12 patients had normal findings on radiographs. The predominant HRCT findings at presentation consisted of unilateral (n = 6) or bilateral (n = 2) ground-glass opacities or focal unilateral (n = 2) or bilateral (n = 2) areas of consolidation. All patients showed progression of disease on follow-up. The predominant HRCT findings on follow-up CT scans consisted of unilateral (n = 2) or bilateral ground-glass opacities (n = 13), unilateral (n = 2) or bilateral consolidation (n = 5), or a mixed bilateral pattern of ground-glass attenuation, consolidation, and reticulation (n = 3). Reticulation with associated architectural distortion and mild traction bronchiectasis was present in eight patients.

CONCLUSION: HRCT can show parenchymal abnormalities in patients with SARS who have normal findings on radiographs at presentation. Follow-up CT scans obtained in hospitalized patients show findings consistent with fibrosis in a small percentage of patients.