注射途径对兔窝淋巴结SPIO增强MR成像的影响

目的探讨不同注射途径对新西兰大白兔腘窝淋巴结SPIO增强MR显影的影响。方法新西兰大白兔12只,雌雄不分,体重2-2.5kg。12只新西兰大白兔双侧后肢大腿肌肉内注射蛋黄乳清液,建立兔腘窝淋巴结反应增生模型;随机分为两组,一组经耳缘静脉注射含10μmolFe的SPIO,一组经后肢趾蹼间皮内注射含10μmolFe的SPIO;MR扫描,包括平扫及注射SPIO后12小时延迟增强扫描。分析两组注射途径MR图像特征,并对照病理检查。结果两组淋巴结大小无差别（p=0.936,〉0.05）。平扫,各种淋巴结T1WI呈低信号或稍高信号;T2WI呈等信号或高信号;PDWI呈低或高信号;GRET2＊WI呈等信号或高信号。增强扫描,第一组腘窝淋巴结在各序列信号表现与平扫无明显变化;第二组,T1WI表现为斑片状低信号或等信号;T2WI表现呈斑片状低信号;PDWI表现为斑片状低信号;GRET2＊WI淋巴结信号几乎完全消失,部分出现过剂量伪影。计算各组淋巴结增强前后信噪比（SNR）,运用重复测量方差分析,得P〈0.01。结论兔腘窝淋巴结SPIO增强MRI检查最佳注射途径为趾蹼间皮内注射。

The Impact Of Injection Methods To the Rabbit Popliteal Lymph Node SPIO Enhanced MR Imaging

Objective To investigate the impact of different injection methods to the rabbit popliteal lymph node SPIO enhanced MR imaging.Methods 12 New Zealand white rabbits:both sexes,the weight is 2~2.5kg.To establish model of reactive hyperplasia of popliteal lymph node,all rabbits were injected with liquid egg yolk in hind leg muscle.12 rabbits were divided into two groups randomly.One group were injected with 10μmol Fe through ear vein;the other group were injected with 10μmol Fe through the hind toe web intradermally.Plain MRI scan and 12 hours delayed enhancement was performed after the injection.MRI images of the two groups were analyzed and compared to the pathology.Results There was no statistical difference in lymph nodes size of the two groups(p = 0.936,> 0.05).In plain scanning,the lymph nodes showed hypointensity or slightly hyperintensity on T1WI,isointensity or hyperintensity on T2WI,hypointensity or hyperintensity on PDWI and isointensity or hyperintensity on GRE T2WI.In enhancement scanning,there was no obvious signal intensity change in any sequence in the first group,while the lymph nodes showed patchy hypointensity or isointensity on T1WI,patchy hypointensity on T2WI and PDWI,and almost no signal and even overdosing artifacts partly on GRE T2WI in the second group.We calculated the SNR of lymph nodes and used repeated measures analysis of variance(P <0.01).Conclusion The optimal method of administrating SPIO to show rabbit’s popliteal lymphnodes is the intradermal injection in toe web.