VALUE OF HIGH-RESOLUTION COMPUTED-TOMOGRAPHY IN ROUTINE EVALUATION OFLUNG TRANSPLANTATION RECIPIENTS DURING DEVELOPMENT OF BRONCHIOLITIS OBLITERANS SYNDROME

Background: Chronic rejection is a major long-term complication after lung transplantation. The purpose of our study was to evaluate the rol e of repeated high-resolution computed tomographic examinations in mon itoring the development of bronchiolitis obliterans syndrome after lun g transplantation. Methods: A total of 126 high-resolution computed to mographic examination in 13 lung transplant recipients was analyzed. D uring a mean follow-up period of 23 months, bronchiolitis obliterans s yndrome developed in eight of the patients. A scoring system from 0 to 10 based on the number of chronic changes on high-resolution computed tomography was developed, and the score of each patient was compared with decline in the forced expiratory volume in 1 second and maximal f orced expiratory flow rate of 50% of the forced vital capacity. Result s: The score of chronic changes, measured at 1 year after transplantat ion, correlated inversely with the values of forced expiratory volume in 1 second and maximal forced expiratory how rate at 50% of the force d vital capacity (p < 0.05). Stage I bronchiolitis obliterans syndrome was associated with scores of 4 to 6 (mean 5.0), stage 2 with scores of 6 to 9 (mean 7.0), and stage 3 with scores of 6 to 9 (mean 7.7). Th e sensitivity of high-resolution computed tomography was 93% and its s pecificity was 92% when five chronic changes were used as a cutoff lev el. Conclusions: The progress of chronic changes on high-resolution co mputed tomography occurs concurrently with the development of bronchio litis obliterans syndrome. High-resolution computed tomography may pro vide additional morphologic information for noninvasive evaluation of chronic lung rejection.