Severe acute respiratory syndrome: thin-section computed tomography features, temporal changes, and clinicoradiologic correlation during the convalescent period.

Wong, Ka-tak; Antonio, Gregory E; Hui, David S C; Ho, Catherine; Chan, Po-nin; Ng, Wing-hung; Shing, Kwok-kuen; Wu, Alan; Lee, Nelson; Yap, Florence; Joynt, Gavin M; Sung, Joseph J Y; Ahuja, Anil T

OBJECTIVE To evaluate thin-section computed tomography findings of patients with severe acute respiratory syndrome (SARS) in the convalescent period and to correlate the results with clinical parameters and lung function tests. METHODS Ninety-nine severe acute respiratory syndrome patients with persistent changes on follow-up chest radiography were included. One hundred seventy computed tomography examinations at baseline (n=70), 3 months (n=56), and 6 months (n=44) were retrospectively evaluated to determine the extent of ground-glass opacification, reticulation, and total parenchymal involvement. Patients' demographic information, clinical information during treatment, and results of lung function tests at 3 and 6 months were correlated with computed tomography findings. RESULTS A significant serial improvement in the extent of overall ground-glass opacification, overall reticulation, and total parenchymal involvement was observed (P <0.01). Advanced age, previous intensive care unit admission, mechanical ventilation, alternative treatment, higher peak lactate dehydrogenase, and peak radiographic involvement during treatment showed a positive correlation with overall reticulation and total parenchymal involvement at 6 months. There was a significant negative correlation between overall reticulation and total parenchymal involvement with diffusion capacity adjusted for hemoglobin at 3 and 6 months (P <0.01). CONCLUSION Lung changes on thin-section computed tomography of severe acute respiratory syndrome patients improved with time during the convalescent period and showed a significant correlation with advanced age, parameters indicating severe illness, and diffusion capacity adjusted for hemoglobin on follow-up.