裸鼠肺腺癌皮下移植瘤模型的建立与MRI活体成像

Transplanted tumor models of lung adenocarcinoma in nude mice and its vivo magnetic resonance imaging

目的:探讨8通道腕关节线圈对裸鼠皮下移植瘤模型的常规MR及扩散加权成像(DWI)可行性及图像质量。方法:将对数期生长的人肺腺癌(A549)细胞悬液种植于14只裸鼠右侧腹股沟皮下,构建肺癌皮下移植瘤模型,将14只成瘤模型鼠用特殊装置分隔并置于MR腕关节线圈内行MR常规及DWI扫描(一次可同时扫描4只裸鼠),观察其成像效果,并与病理结果对照。结果:3~6周后,裸鼠皮下移植瘤大小约1.1 cm^2.2 cm,14只裸鼠人肺腺癌皮下移植瘤成瘤率100%(14/14)。所有裸鼠均完成MR显像,T2WI图像能够清晰显示14只(14/14)皮下移植瘤大小、形态及邻近组织,肿瘤T2WI呈高信号,囊变坏死区呈更高信号;DWI上肿瘤显示良好无变形6只(6/14);DWI图像变形但不影响观察6只(6/14),瘤周明显伪影及变形2只(2/14)。肺腺癌皮下移植瘤均经过病理结果证实。结论:8通道腕关节线圈可一次完成多只裸鼠MR常规及DWI成像,节省扫描时间,能够清晰显示肿瘤的大小、形态及信号,适于裸鼠移植瘤磁共振MR活体研究。

Objective：To study the value of 8 channel wrist coil on conventional MR and the quality of diffusion-weighted images（DWI） of transplanted lung adenocarcinoma on a nude mouse.Methods：The tumor pieces of human lung adenocarcinoma A549 were implanted subcutaneously in 14 nude mice,These mice which were separated by special devices were scanned with MR wrist coil（4 nude mice can be scanned at the same time）,from which conventional MR and EPI-DWI were obtained after tumor growth and compared with pathological findings.Results：The tumor size in nude mice was about 1.1 cm to 2.2 cm after 3 to 6 weeks,the tumor-formation rate was 100%.14 nude mice was performed by MR,All tumors and abdominal organ were detected clearly on T2WI images,and shown as Hyper-intensity and more hyper-intensity in necrotic areas;Compared with the T2WI,DWI showed no geometric deformation in 6 mice,moderate to slight geometric deformation in 6 mice which remained detectable,conspicuous geometry deformation in 2 mice to cause difficult detection.Conclusion：The 8 channel wrist coil can complete multiple conventional MR and DWI imaging in nude mouse at the same time.The special devices not only save time,but also allow convenient tumor observation on conventional MR and DWI,suggesting the validity of this model for MR research of nude mouse transplanted tumor.