RADIATION-INDUCED LUNG INJURY USING A PIG MODEL - EVALUATION BY HIGH-RESOLUTION COMPUTED-TOMOGRAPHY

RATIONALE AND OBJECTIVES. TO assess the early phase of radiation-induc ed lung injury using high-resolution computed tomography (CT) under ex perimental conditions and to perform precise CT-pathologic correlation . METHODS. Five Yorkshire pigs received a single dose of 12.5 Gy to th e right lower lung, Computed tomographic images were obtained at 2-wee k intervals, The animals were killed after follow-up periods of 4-16 w eeks, The lungs were removed, inflated, fixed, dried, and sliced corre sponding to the CT sections, Computed tomography, specimen radiography , and histologic findings were correlated.RESULTS. Various CF findings were observed during the first 16 weeks, including ground-glass opaci ty, discrete consolidation, patchy consolidation, thickened interlobul ar septum, and bronchovascular bundle, Ground-glass opacity was associ ated with thickened alveolar wall and scattered tiny fibrotic foci, Th ickened interlobular septum and bronchovascular bundle were the result s of fibrosis adjacent to these structures, Discrete consolidation cor related with intraalveolar edema with hemorrhage and infiltration of i nflammatory cells. CONCLUSIONS. High-resolution CT correlated well wit h pathology of the lung due to radiation injury as verified by precise radiologic-pathologic correlation.