OBJECTIVETo observe initial radiographic manifestations and evaluate its value for the diagnosis and differential diagnosis in patients with severe acute respiratory syndrome (SARS).

METHODSInitial chest radiographs of 79 patients, 15 to 69 years old (mean age 34.1 years, 40 men and 39 women), were retrospectively reviewed in the study. For all patients, average temperature was 38.8 degrees C and mean time from onset of the fever to the time of initial radiographs taken was 5.8 days. Location, abnormal distribution, appearance of lung abnormalities, effusion of pericadiaum and pleura, and lymphadenopathy were observed. Abnormal distribution and associated findings were compared. Differences of mean age, temperature, and the time were statistically analyzed between patients with and without abnormal findings.

RESULTSInitial chest radiographs were normal in 36 of 79 patients (45.5%). Abnormal radiographs in 43 patients (81.3%) showed exudative changes. No significant difference of mean age and day (form onset of the fever to the time of initial radiographs taken) was found between the patients with and without abnormal initial chest radiographs (P > 0.05). No lymphadenopathy, effusion of pericadiaum and pleura were found on the initial chest radiographs.

CONCLUSIONSThe main abnormal radiographic appearance of lung in patients with SARS is exudative changes. SARS patients with normal initial chest radiographs are not uncommon and abnormal radiographic findings may appear to be late after onset of fever. Therefore, more attention should be paid in the clinical diagnosis of SARS.