自主研发小动物专用磁共振显微线圈的研究应用

目的探讨临床磁共振成像系统应用自主研发小动物专用磁共振显微线圈在啮齿小动物实验研究中的价值。方法采用Siemens Avanto 1.5T超导临床磁共振成像扫描仪和25mm实验动物专用磁共振显微线圈,分别进行基因敲除小鼠脑TSE序列T2WI解剖结构成像、裸鼠皮下种植人型结肠肿瘤模型TSE序列T1WI和T2WI横断位扫描、水分子弥散加权成像和造影剂动态增强扫描（DCE）和肥胖小鼠模型肝内脂肪化学位移成像检测及腹部脂肪波谱分析。结果基因敲除小鼠脑T2WI图像高分辨清晰显示脑皮层厚度、皮髓质分界及丘脑和脑室结构;裸鼠皮下种植人型结肠肿瘤模型清晰显示其肿瘤组织解剖结构和信号、水分子弥散影像,同时通过DCE扫描可获取肿瘤血管的通透性检测指标;肥胖小鼠模型化学位移成像显示肝内脂肪浸润,而且波谱可定量分析腹部脂肪。结论临床1.5T超导磁共振成像扫描仪结合25mm实验小动物专用显微线圈可清晰地显示小鼠脑部、裸鼠皮下肿瘤模型肿瘤解剖组织结构,而且还可进行分子、功能成像和脂肪的检测和波谱定量分析,为基础实验提供准确可靠的影像学信息。

Preliminary application of a novel MRI micro-coil for small rodent animal

【Objective】To evaluate the usefulness and feasibility of a homemade micro-coil applied with clinical MRI(cMRI)for small rodent animal imaging research.【Methods】The gene knock down mouse brain,nude mouse with a human-colon-cancer xenograft model,and fatty mouse abdomen underwent Siemens Avanto 1.5T MRI applied with 25mm micro-coil.TSE T2WI was performed for the anatomic mouse brain,TSE T1WI,T2WI,diffusion weighted imaging(DWI) and dynamic contrasted enhancement for xenograft model and chemical shift imaging(CSI) for fatty liver detection as well as MRS for abdominal lipids on fatty mouse model.【Resluts】The cortex thickness,corticomedullary demarcation,thalamus and ventricles of the gene knock-down mouse brains were clearly displayed on T2WI with high resolution and signal noise ratio(SNR).Subcutaneous human-colon-cancer xenograft tumors on nude mice were shown with high SNR and water molecular DWI,and the tumor vessel permeability was detected by DCE.The hepatic and abdominal adipose of fatty mice was detected by CSI and quantitatively analyzed by MRS.【Conclusion】The clinical high field MRI combined with 25 mm micro-coil might image mouse brain,subcutaneous xenograft on nude mouse with high resolution and SNR of anatomical structures as well as molecular and functional imaging and quantitatively analysis.It would provide the reliable and accurate image information for basic science.