Thin-Section Computed Tomography Manifestations During Convalescence and Long-Term Follow-Up of Patients with Severe Acute Respiratory Syndrome (SARS)

Abstract

BACKGROUND SARS is not only an acute disease, but also leads to long-term impaired lung diffusing capacity in some survivors. However, there is a paucity of data regarding long-term CT findings in survivors after SARS. The aim of this study was to assess the changes in lung function and lung thin-section computed tomography (CT) features in patients recovering from severe acute respiratory syndrome (SARS), especially the dynamic changes in ground-glass opacity (GGO). MATERIAL AND METHODS Clinical and radiological data from 11 patients with SARS were collected. The serial follow-up thin-section CTs were evaluated at 3, 6, and 84 months after SARS presentation. The distribution and predominant thin-section CT findings of lesions were evaluated. RESULTS The extent of the lesions on the CT scans of the 11 patients decreased at 6 and 84 months compared to 3 months. The number of segments involved on 84-month follow-up CTs was less than those at 6 months (P<0.05). The predominant thin-section CT manifestation at 84 months (intralobular and interlobular septal thickening) was different than that at 6 months, at which GGO was predominant. CONCLUSIONS During convalescence after SARS, GGO and intralobular and interlobular septal thickening were the main thin-section CT manifestation. Intralobular and interlobular septal thickening predominated over GGO at 84 months.

Figure 1

Case 1, SARS survivor, female, 30 years old. (A) The CT scan at 3 months showed diffuse bilateral GGO (arrow). (B) Six months later, GGO was reduced. (C) At 84 months, GGO was greatly reduced and fine reticulation (intralobular and interlobular septal thickening) predominated (arrow). Patchy decreased attenuation was seen at 3-, 6-, and 84-month CT (triangle).

Figure 2

Case 7, SARS survivor, male, 31 years old. (A) Chest radiography showed consolidation in the lower lobes of both lungs in acute phase. (B) Six months later, GGO (triangle) and reticulation (arrow) were observed in both lungs. (C) Fine reticulation (arrow) still persisted but GGO could not be found at 84-month CT.

Figure 3

Case 6, SARS survivor, female, 32 years old. (A) X-ray radiography showed a large consolidation in the lower lobes of both lungs in acute phase. (B) Six months later, X-ray revealed GGO, septal thickening, and fine-mesh shadows (white arrow). Traction bronchiectasis was found in the left lower lobe. (C) At 84 months, GGO was reduced and interlobular thickening predominated. Traction bronchiectasis was still present.