CORRELATION OF HIGH-RESOLUTION CT AND PULMONARY-FUNCTION IN BRONCHIOLITIS OBLITERANS - A STUDY BASED ON 24 PATIENTS ASSOCIATED WITH CONSUMPTION OF SAUROPUS-ANDROGYNUS

OBJECTIVE. An outbreak of Sauropus androgynus-associated bronchiolitis obliterans occurred in Taiwan in the summer of 1995. We undertook a s tudy of the correlation between high-resolution CT findings and pulmon ary function testing in patients from this outbreak. MATERIALS AND MET HODS. We evaluated inspiratory-expiratory high-resolution CT scans of 24 patients with S. androgynus-associated bronchiolitis obliterans. Th e presence of bronchiectasis was assessed by two visual scores (a bron chial dilatation score and a bronchiectasis extent score). Extent of a ir-trapping was assessed visually and given a score. We also used comp uter software to assess the extent of air-trapping and generate scores of dynamic attenuation. Spirometry, plethysmography, and diffusion ca pacity of each patient were also obtained. RESULTS. All four scores ha d statistically significant correlation with forced expiratory volume in 1 sec (FEV(1)) (p < .05 for both bronchiectasis scores; p < .001 fo r both air-trapping scores). The two air-trapping scores had statistic ally significant correlation with forced vital capacity and diffusion capacity. We found the scores for dynamic attenuation had the greatest correlation with FEV(1) (r = .85). We also found that mosaic attenuat ion was notable on expiratory CT scans alone in nine patients (type 1 air-trapping) and on both inspiratory and expiratory CT scans in 15 pa tients (type 2 air-trapping). In the latter group, FEV(1) was signific antly lower (p < .01). CONCLUSION. Findings from high-resolution CT of air-trapping were more important than findings of bronchiectasis when correlating pulmonary function with S. androgynus-associated bronchio litis obliterans. Type 2 air-trapping suggested a more severe air-flow obstruction than did type 1. Scores for quantitative attenuation gene rated by computer software were helpful in assessing air-trapping and correlating it with pulmonary function. These findings may apply to pa tients with bronchiolitis obliterans from other causes.