Severe acute respiratory syndrome: temporal lung changes at thin-section CT in 30 patients.

PURPOSE: To evaluate lung abnormalities on serial thin-section computed tomographic (CT) scans in patients with severe acute respiratory syndrome (SARS) during acute and convalescent periods. MATERIALS AND METHODS: Serial thin-section CT scans in 30 patients (17 men, aged 42.5 years +/- 12.2 [SD]) with SARS were reviewed by two radiologists together for predominant patterns of lung abnormalities: ground-glass opacities, ground-glass opacities with superimposed linear opacities, consolidation, reticular pattern, and mixed pattern (consolidation, ground-glass opacities, and reticular pattern). Scans were classified according to duration in weeks after symptom onset. Longitudinal changes of specific abnormalities were documented in 17 patients with serial scans obtained during 3 weeks. Each lung was divided into three zones; each zone was evaluated for percentage of lung involvement. Summation of scores from all six lung zones provided overall CT score (maximal CT score, 24). RESULTS: Median CT scores increased from 1 in the 1st week to 12.5 in the 2nd week. Ground-glass opacities with or without smooth interlobular septal thickening and consolidation were predominant patterns found during the 1st week. Ground-glass opacities with superimposed irregular reticular opacities, mixed pattern, and reticular opacities were noted from the 2nd week and peaked at or after the 4th week. After the 4th week, 12 (55%) of 22 patients had irregular linear opacities with or without associated ground-glass opacities and CT scores greater than 5; five of these patients had bronchial dilatation. When specific opacities were analyzed in 17 patients, consolidation generally resolved completely (n = 4) or to minimal residual opacities; six (55%) of 11 patients with ground-glass opacities had substantial residual disease (CT scores > 5) on final scans. CONCLUSION: There is a temporal pattern of lung abnormalities at thin-section CT in SARS. Predominant findings at presentation are ground-glass opacities and consolidation. Reticulation is evident after the 2nd week and persists in half of all patients evaluated after 4 weeks. Long-term follow-up is required to determine whether the reticulation represents irreversible fibrosis.

Severe acute respiratory syndrome: radiographic evaluation and clinical outcome measures.

PURPOSE: To evaluate the relationship among chest radiographs, oxygen supplementation requirement, and treatment response in severe acute respiratory syndrome (SARS). MATERIALS AND METHODS: Forty patients (20 women, 20 men; mean age, 42.90 years +/- 14.01 [SD]; median age, 41.5 years; age range, 25-82 years) with SARS were evaluated. Daily chest radiographs were graded according to percentage of lung involvement during 20.15 days +/- 5.56 (median, 20 days; range, 14-38 days). Times between symptoms and treatment and time to reach maximal radiographic score from admission and treatment day were determined. Daily oxygen saturation (Sao2) and oxygen supplementation including mechanically assisted ventilation were recorded. Treatment response was defined as good, fair, and poor. Patterns of radiographic opacity at admission and at maximal radiographic score were noted. Differences in radiographic and clinical parameters with respect to oxygen supplementation and treatment response were respectively evaluated with Mann-Whitney and Kruskal-Wallis tests. RESULTS: Larger maximal radiographic scores, lower Sao2 at maximal radiographic change, longer time from treatment to maximal radiographic score (P <.01), and diffuse consolidation at maximal radiographic score were associated with oxygen supplementation. Parameters that influenced treatment response were time from symptom onset to treatment day (P =.003), time from admission to treatment day (P <.001), time to maximal radiographic score from treatment day (P =.001), maximal radiographic score (P =.009), Sao2 at maximal radiographic score (P =.13), and treatment radiographic score (P =.03). Fair responders had shorter time between admission and treatment than did either good (P <.001) or poor responders (P =.002) and shorter time between symptoms and treatment (P <.001) and lower treatment radiographic score (P =.012) than did good responders. Good (82%), poor (36%), and fair (33%) responders developed maximal chest radiographic scores within 4 days of treatment (P =.008). Radiographic patterns at both admission and maximal radiographic score did not influence treatment response. CONCLUSION: There are significant relationships among radiographic parameters, oxygen supplementation, and treatment response, and these relationships appear to be clinically useful in the treatment of SARS.

Severe acute respiratory syndrome: relationship between radiologic and clinical parameters.

PURPOSE: To quantify severity of severe acute respiratory syndrome (SARS) on chest radiographs and to determine its relationship with clinical parameters. MATERIALS AND METHODS: Forty patients (mean age, 42.90 years +/- 14.01 [SD]; median age, 41.5 years; age range, 25-82 years) with clinically diagnosed SARS were evaluated. Heart rate, oxygen saturation, temperature, and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were recorded daily. Severity of lung changes on chest radiographs was scored according to percentage of involved lung. Radiographic scores at days of admission, treatment, and maximal radiographic score were extracted for statistical analysis with clinical parameters. Time to maximal radiographic score from admission and days between onset and beginning of treatment were determined. Correlations between radiographic and clinical parameters were evaluated with Spearman rank correlation. Sex differences with respect to clinical and radiographic parameters were evaluated with Mann-Whitney test. RESULTS: Median chest radiographic scores peaked 5 days after beginning of treatment before they declined. Maximal and treatment radiographic scores were inversely related to oxygen saturation (r = -0.67, P <.001; r = -0.35, P =.03). Admission radiographic score was correlated with admission AST level (r = 0.53, P =.003); treatment radiographic score, with treatment ALT and AST levels (r = 0.43, P =.007; r = 0.42, P =.019); and time to maximal radiographic score, with AST level at maximal radiographic score (r = -0.45, P =.006), admission radiographic score (r = -0.55, P <.001), treatment radiographic score (r = -0.58, P <.001), and admission ALT and AST levels (r = -0.44, P =.007; r = -0.58, P =.001). Treatment delay was associated with AST level at maximal radiographic score (r = 0.53, P =.001), treatment radiographic score (r = 0.60, P <.001), and time to maximal radiographic score (r = -0.36, P =.02). No sex differences occurred with respect to radiographic and clinical parameters (P >.05). CONCLUSION: Severity of lung abnormalities quantified on chest radiographs correlates with clinical and laboratory parameters.