兔VX2肝癌模型动态磁共振扩散张量成像的量化研究

Quantitative study of dynamic MR diffusion tensor imaging in rabbit VX2 liver tumor model

目的探讨对兔VX2种植型肝癌模型的成瘤过程进行动态磁共振扩散张量成像(DTI)量化研究的可行性及价值。方法在肿瘤植入后第14、18、22、26天分别对4组共16只新西兰大白兔VX2种植型肝癌模型和4组共4只正常新西兰大白兔进行磁共振成像及DTI;动态量化分析平均扩散系数(DCavg)、部分各向异性值(FA)的变化规律并与病理结果对照。结果兔VX2种植型肝癌模型的DCavg呈先递增后递减趋势;FA呈先递减后递增趋势;与对照组间差异有显著性;病理结果的多项分析中,瘤内凝固性坏死和纤维增生呈明显递增趋势。结论DTI的量化指标能够动态观测兔VX2种植型肝癌模型的部分生长特性;为DTI对肝脏病变的临床应用提供一定的理论指导。

Objective To investigate the possibility of dynamic MR diffusion tensor imaging （DTI） in rabbit VX2 liver tumor model. Methods MRI and DTI images were obtained with 16 rabbit VX2 liver tumor model and 4 normal rabbits, 14, 18, 22 and 26 days after tumor implanted, average diffusion coefficient （DCavg）, fractional anisotropy （FA） were estimated and compared by pathology. Results The DCavgs of the experimental groups had a descending trend and FAs had an increasing trend, which had significant differences comparing to contrast group; the occurrences of coagulation necrosis and fiber hyperplasia had an increasing trend in pathologic results. Conclusion Dynamic MR DTI quantitative analysis had significant values in differentiate some characteristics of rabbit VX2 liver tumor model, and it could instruct to clinical application of MR DTI in theory.