Evaluation of chronic pulmonary emphysema ultrafast computed tomography

We compared pulmonary ventilation dynamics between 41 patients with pulmonary emphysema and 11 healthy subjects with normal pulmonary function using ultrafast computed tomography (CT). Regions of interest (ROIs) for multislice scanning were selected from the anatomical levels of the carina in the right upper lung field. Several identical slices were selected from the inspiratory and expiratory scans. The average CT values in the ROIs (AvROI) were obtained during the inspiratory phase (inAvROI) and the expiratory phase (exAvROI. The ratio of change from inAvROI to exAvROI ((I-E)/E ratio) was also used for image analysis. Furthermore, possible correlations between the CT image parameters and pulmonary function test parameters were examined. The results showed that the exAvROI and inAvROI values and (I-E)/E ratio were lower in the emphysema group than in the normal pulmonary function group. Among the image data parameters, the exAvROI value correlated most closely with pulmonary function parameters, in particular, with the pulmonary diffusing capacity. These findings suggest that image data parameters of ventilation dynamics may be useful for evaluating the severity of pulmonary emphysema. (author)