Hyperoxia-induced Acute Lung Injury Using a Pig Model: Correlation between MR Imaging and Histologic Results

PURPOSE: To correlate MR imaging findings with pathology in experimental hyperoxia-induced acute lung injury, which has similar pathology to diffuse alveolar damage (DAD). MATERIALS AND METHODS: Seventeen Yorkshire pigs were studied. These animals were exposed to more than 80% oxygen for 24, 48, 72, and 96 hours in a sealed cage. The lungs were removed and inflated with air infused through the trachea, and then examined by both MRI and high-resolution CT (HRCT). T1-weighted spin-echo (T1WSE), T2-weighted fast (T2WFSE), and half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences were performed. RESULTS: Severity in MR findings and signal-to-noise ratios (SNR) on MR images were well correlated with pathological scores. CT values were also correlated well with pathologic scores. Abnormal SNR values were obtained from a pathological score of 5, whereas abnormal CT values were obtained from a pathological score of 15. Furthermore, significant differences in SNR were observed in each histopathological phase. CONCLUSION: SNRs on MR images were superior to CT values in detecting early pathologic changes in DAD. MR study also is potentially useful for evaluation of the histopathological phases in acute lung injury.