Clinical and imaging analysis of SARS

Objective: To investigate the clinical and imaging characteristics of the severe acute respiratory syndrome (SARS), and to study the relationship between imaging and clinical findings. Methods: Forty-six patients with SARS verified by imaging and clinical data were reviewed. X-ray examination data were available in all cases and chest CT scanning was acquired in 6 cases. The X-ray and CT findings were analyzed retrospectively. Results: Fever was found in 97.8%(45/46) of the patients. The clinical symptoms were mild, but findings on X-ray film and CT were distinct. Pulmonary interstitial infiltration was demonstrated on X-ray films at the onset, and then the lesion could involve the pulmonary parenchyma. (1) Location: bilateral lung involvement was revealed in 17 cases (37.0%), and unilateral involvement in 29 (63.0%). In the unilateral lung involvement group, right lung involvement was found in 14 cases (14/29), and left in 15 (15/29). The lesion was confined within one lobe in 28 cases (60.9%), two lobes in 9 (19.6%), three lobes in 4, four lobes in 4, and five lobes in 1, respectively. In cases with multiple lobe involvement, the lesion was limited to one side of the lung in 1 case (1/18), and bilateral lung involvement in 17 (17/18). (2) Type: change of lung markings in 3 cases (6.5%), interstitial type in 18 (39.1%), consolidation type in 9 (19.6%), and mixed type in 16 (34.8%). Besides, blurred hilum in 1 case, small amount of pleural effusion in 1 case, and mild pleural reaction in 1 case was detected, respectively. CT scanning demonstrated ground-glass hyperdense lesions or large patchy exudation and consolidation at the early stage in 3 cases. The different findings on X-ray and CT were related to the different phase of the disease. After treatment, most lesions were absorbed completely, but the lesions were absorbed slowly for 3 patients with multi-lobe consolidation or/and extensive interstitial infiltration. Conclusion: SARS had characteristic clinical and imaging findings. The prognosis of SARS was related to the degree of lesions on X-ray and CT film