低磁场核磁共振对小鼠原发性和移植性肿瘤的成像效果

目的 利用小鼠原发性和移植性肿瘤模型检测0.5T低磁场小动物核磁共振（MRI）的成像效果。方法 采用0.5T低磁场MRI仪对小鼠皮下移植瘤（HepG2、S180、H-ras12V转基因小鼠肝肿瘤组织）和原发性肝肿瘤（H-ras12V转基因肝癌小鼠）进行检测，观察其影像学表现并对H-ras12V转基因小鼠原发性肝肿瘤进行病理学确认。结果 皮下移植瘤小鼠（S180、HepG2、H-ras12V转基因小鼠肝肿瘤组织）的肿瘤生长状态良好，肉眼及X光检测均可观察到显著的肿瘤团块。MRI成像结果表明，皮下肿瘤部位的T1WI上表现为低信号、T2WI上表现为高信号、成像清晰、效果良好，且三种小鼠皮下移植瘤的MRI成像效果相似。对于H-ras12V转基因小鼠原发性肝肿瘤的MRI成像结果表明，在转基因小鼠的肝区出现了T1WI上表现为低信号的多个区域，这些相应区域在T2WI上表现为高信号。病理解剖及病理切片证实，这些区域为多发性肝肿瘤。结论 利用低磁场MRI可以对小鼠原发性肝肿瘤和移植性肿瘤进行有效的检测，可作为小鼠肿瘤无创检测的有效方法。

Imaging Effect of Low-field MRI on Primary Tumors and Transplanted Tumors in Mice

Objective To investigate the imaging effect of 0.5T low-field MRI on mice harboring primary liver tumors and subcutaneously transplanted tumors. Methods The 0.5T low-field MRI was conducted on mice bearing HepG2, S180, and liver tumor tissues of H-ras12V transgenic mice and primary liver tumors(Hras12V transgenic mice). The primary liver tumors of H-ras12V transgenic mice were confirmed by histopathological examination. Results The subcutaneously transplanted tumors (HepG2, S180, liver tumor tissues of H-ras12V transgenic mice) grew well and the tumor masses could be clearly observed by naked eyes and X optical detection. The MRI imaging results showed that the location of transplanted tumors clearly presented hypointense signal on T1WI and hyperintense signal on T2WI. The MRI imaging manifestations of three kinds of subcutaneously transplantated tumors were consistent. For the H-ras12V transgenic mice, the MRI imaging results showed that several separated regions presented hypointense signal on T1WI and hyperintense signal on T2WI in the location of liver. These regions were finally confirmed to be multiple liver tumors by anatomy and histopathological examination. Conclusion The low-field MRI provides an effective and noninvasive diagnostic method for detecting primary liver tumor and transplanted tumor in mice.