[Computed tomographic-pathologic correlation of centriacinar emphysema].

Centriacinar emphysema (CAE) is in principle defined and diagnosed pathologically. However, recently, computed tomography (CT) has been advocated in the diagnosis of emphysema because of the high degree of anatomic details it can provide. In order to assess the reliability and detectionability of CT in CAE detection, as well as evaluation of the severity, a CT-pathologic correlative study of CAE was performed. To study direct one-to-one CT (in vivo)-pathologic correlation, 20 lung lobes with CAE from autopsies and resections were inflated and fixed by the method of Heitzman et al and then sectioned along the plane equivalent to the CT images. The degree of CAE was graded pathologically by the point-counting method. The CT scans were assessed visually for low-attenuation areas by 3 independent physicians. A significant correlation was found between the CT and pathologic scores of the studied lobes (r = 0.94). Detectionability of CAE on lung slices by CT were 74%, 91%, and 100% for mild, moderate, and severe cases respectively. The smallest size of the diameter of emphysematous spaces which could be detected by CT with 10 mm collimation was 3-4 mm. We concluded that CT extremely useful in assessing the extent of CAE, however there are limitation in the diagnosis of mild cases. Moreover, visual scoring of low-attenuation areas on CT images was found to be clinically useful in the quantitative evaluation of CAE.