Artificial ventilation-induced diffuse alveolar damage in rabbits - Preliminary study of early detection on expiratory high-resolution computed tomography

RATIONALE AND OBJECTIVES. TO investigate whether expiratory high-resolution computed tomography (HRCT) is more useful than inspiratory HRCT for the de tection of early-phase diffuse alveolar damage. METHODS. Eleven anesthetized rabbits were scanned with both inspiratory and expiratory HRCT every 30 minutes during mechanical ventilation. Ten rabbit s were killed after the detection of pulmonary abnormalities on both inspir atory and expiratory HRCT, The remaining rabbit was killed when the pulmona ry abnormalities appeared only on expiratory HRCT. RESULTS. In four cases (36%), the abnormal findings were detected earlier o n expiratory HRCT than on inspiratory HRCT. In seven cases (64%), the abnor malities appeared simultaneously on inspiratory and expiratory HRCT, In all 11 cases, the histopathological changes of areas with abnormal CT findings corresponded to the exudative or proliferative phase of diffuse alveolar d amage. CONCLUSIONS. Expiratory HRCT has the potential to detect the abnormalities of diffuse alveolar damage earlier than inspiratory HRCT.