Abstract

BACKGROUND: The most common cause of death from paraquat (PQ) poisoning is respiratory failure from pulmonary fi brosis, which develops through pathological overproduction of extracellular matrix proteins such as collagens. In this study, a MicroCT system was used to observe dynamic changes of pulmonary fi brosis in rats with PQ poisoning, and fi nd the characteristics of interstitial lung diseases via density-based and texture-based analysis of CT images of the lung structure. METHODS: A total of 15 male SD rats were randomly divided into a control group (n=5) and a PQ poisoning group (n=10). The rats in the poisoning group were intraperitoneally administered with 4 mg/ mL PQ at 14 mg/kg, and the rats in the control group were administered with the same volume of saline. The signs of pulmonary fi brosis observed by the MicroCT included ground-glass opacity, nodular pattern, subpleural interstitial thickening, consolidation honeycomb-like shadow of the lung. RESULTS: Compared with the control group, the rats with acute PQ poisoning had different signs of pulmonary fibrosis. Ground-glass opacity and consolidation of the lung appeared at the early phase of pulmonary fi brosis, and subpleural interstitial thickening and honeycomb-like shadow developed at the middle or later stage. MicroCT images showed that fibrotic lung tissues were denser than normal lungs, and their density was up-regulated with pulmonary fi brosis. There was no difference in the progress of pulmonary fi brosis between the right lung and the left lung (P>0.05), but there were differences in fi brosis degree at different sites in the lung (P<0.05 or P<0.01). Pulmonary fi brosis was mainly seen in the exterior area of the middle-lower part of the lung. CONCLUSION: Imaging can show the development of pulmonary fi brosis in PQ poisoning rats, and this method may help to administer drugs more reasonably in treating pulmonary fi brosis.

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