Severe acute respiratory syndrome: radiographic review of 40 probable cases in Toronto, Canada.

Abstract

To review radiographic findings of patients with probable severe acute respiratory syndrome (SARS) who were seen at a University of Toronto (Ontario, Canada) teaching hospital. Findings were reviewed for 40 patients who fulfilled the World Health Organization criteria for probable SARS. A template was designed for the analysis of each serial radiograph to observe patterns and distribution of disease, interval changes, and complications. The majority of radiographs were anteroposterior views. A clinical database of these patients was also collected for clinical-radiologic comparison. The mean age of the patients (18 male, 22 female) was 42.7 years. Patients had a normal chest radiograph and focal, multifocal, and/or bilateral consolidation. The pattern of consolidation tended to be peripheral and poorly marginated and involved middle and lower lung zones. The serial sequence fell into two major subgroups, which correlated closely with clinical outcome. Consolidation in one group cleared within a matter of days, while the second group went on to develop rapid and extensive bilateral pneumonia, with a prolonged hospital stay. Subsegmental atelectasis and pleural complications were rarely observed. SARS pneumonia can manifest as focal peripheral consolidation that clears relatively quickly and does not cause secondary complications or that progresses to bilateral consolidation and a more protracted clinical course.