实验性特发性肺纤维化的早期影像研究——动物模型的建立

Experimental imaging studies of early - stage idiopathic pulmonary fibrosis - animal model and preliminary results

目的 通过对平阳霉素诱导的大鼠和兔IPF模型的高分辨率CT图像和病理结果的对照分析,确定兔在复制IPF模型上的可行性。方法 实验中采用了3只大鼠和7只白兔。通过气管插管的方法向两侧主支气管内灌入平阳霉素。在预设的时间扫描动物后即处死,采取肺组织进行固定和切片染色。在光学显微镜下观察,同时将病理结果与影像表现作对照分析。结果 大鼠的HRCT图像质量差,仅能识别肺内的大血管和叶、段级的支气管结构,而对肺内的其它组织则显示不清。而兔的HRCT图像可以揭示较多的间质性病变和气腔病变的信息。在平阳霉素处理后的14天内肺内病变以炎性渗出为主,血管的周围可见较多的红、白细胞,肺泡腔内充有水肿液,此时图像中的表现主要为磨玻璃样影;而28天时HRCT中已见多量的纤维增生所致的线样、网织状及结节影。结论 本研究认为:大鼠不适合作为HRCT研究的模型动物;兔肺模型提供了可靠的典型间质病变特征,因而可以应用到HRCT的研究中;针对小型动物采用2mm层厚的超高分辨算法得到的肺部图像,较标准的2mm层厚的HHCT图像的质量更佳。

Purpose To determine the feasibility of rabbit as an animal model to replicate the pulmonary fibrosis. Methods 3 male Wistar rats (body weight, 150- 180g) and 7 male New Zealand white rabbits received a single intratracheal bleomycin injection via the endotracheal tube. Following HRCT scan on a presetting time point,lungs underwent pathologic procedures which helped HRCT features to be evaluated and defined. Results In HRCT of rats with a poor quality, only main bronchi and larger vessels could be recognized. In contrast, images of rabbits offered much information about interstitial and air- space abnormality. On day 14,ground glass opacity reached its maximal severity in spite of less extent than before, with edema exudation full of alveolar space. Linear structures, subpleural line and nodular opacity occruued on 28th day HRCT. Conclusions Rabbit is suitable to be employed as the experimental subject in imaging studies, and with 2mm - diameter collimation, the quality of images reconstructed by ultrahigh resolution algorithm are much more excellent than by high resolution, so in small animal lung scan, an ultrahigh resolution CT(uHRCT) can be proposed.