阳性亲淋巴对比剂增强MR淋巴造影对淋巴结成像的实验验证

Experimental study of lymph node imaging by MR contrast enhanced contrast agent

目的研究大分子阳性亲淋巴对比剂二氨基乙基乙二醇醚-DTPA酰胺共聚物钆配合物(Gd-poly-DTPA-EOEA)增强MR淋巴造影对肿瘤转移、炎性增生淋巴结显像的鉴别诊断价值。方法本研究共14只新西兰大白兔,其中7只于后肢注射完全型免疫佐剂,建立腘窝淋巴结的炎性增生组模型,另7只于后肢肌肉内接种VX2瘤,建议腘窝淋巴结肿瘤转移模型,对侧正常腘窝淋巴结作为对照。实验兔在接种前后行2次MR淋巴造影检查。图像3D重建后,选取兔腘窝淋巴结中直径最大者测量其各观察时间点的信噪比。采用成组设计t检验比较每一观察时间点的正常对照侧、炎性增生侧、肿瘤转移侧淋巴结之间的信噪比差异,并与病理检查结果相对照。结果1只兔接种肿瘤未成功,其他接种均良好。全部模型兔均完成二次MR淋巴造影检查。在MR淋巴造影图像上,炎性增生组在各扫描时间点,炎性侧与对照侧腘窝淋巴结信噪比之间差异均无统计学意义(P>0.05)。肿瘤转移组在各扫描时间点,肿瘤侧与对照侧腘窝淋巴结信噪比之间差异均有统计学意义(P<0.01)。进一步比较炎性侧和肿瘤侧腘窝淋巴结,在各扫描时间点,炎性侧与肿瘤侧腘窝淋巴结信噪比差异有统计学意义(P<0.01)。结论基于大分子阳性亲淋巴对比剂Gd-poly-DTPA-EOEA增强的MR淋巴造影是特异性地鉴别良、恶性淋巴结的敏感检查方法。

Objective To explore the differential diagnostic value of macromolecular positive lymphophilic contrast agent diaminoglycol ether DTPA amide copolymer gadolinium complex(Gd-poly-DTPA-EOEA)enhanced MR lymphography(MRL)in lymph node imaging of tumor metastasis and inflammatory hyperplasia.Methods A total of 14 New Zealand white rabbits.Seven rabbits were injected with complete immune adjuvant at the hind limb to establish an inflammatory hyperplasia group model of popliteal fossa lymph node.The Other 7 were inoculated with VX2 tumor in the posterior limb muscle,suggesting the popliteal fossa lymph node metastasis model and the opposite normal popliteal fossa lymph node as the control.Two magnetic resonance lymphography were performed before and after inoculation.After 3D reconstruction,the signal to noise ratio(SNR)of the largest rabbit popliteal fossa nodes was measured.The SNR differences between normal control side,inflammatory hyperplasia side and metastatic side lymph nodes at each observation time point were compared with the results of pathological examination.Result One rabbit was not successfully inoculated with tumor,and other inoculations were good.All the model rabbits completed the secondary MR lymphography.On the MR lymphangiography image,there was no significant difference between the inflammatory side and the control side popliteal fossa nodes SNR at all scanning time points in the inflammatory hyperplasia group(P>0.05).In the tumor metastasis group,there were significant differences between the tumor side and the control side popliteal fossa lymph node SNR at each scanning time point(P<0.01).Further comparison was made between the inflammatory side and the tumor side popliteal fossa lymph nodes.The difference between the inflammatory side and the tumor side popliteal fossa lymph nodes SNR was significant at each scanning time point(P<0.01).Conclusion MR lymphography(MRL)based on macromolecular positive lymphophilic contrast medium(Gdpoly-DTPA-EOEA)enhancement is a sensitive method for differentiating benign from malignant lymph nodes.