MR淋巴管造影显示VX2兔乳腺癌前哨淋巴结

目的:探讨钆剂增强的MR淋巴管造影(MR- LG)用于VX2兔乳腺癌前哨淋巴结(SLN)显像的可行性.方法:采用VX2肿瘤软组织块悬液注射法建立30只兔原位乳腺癌动物模型.实验兔在肿瘤接种前后共行2次MR- LG检查(包括对比剂注射前的STIR序列扫描).图像3D重建后,淋巴管引流通路上距离原发肿瘤最近的淋巴结定义为SLN,且成像效果根据3D图像上有无淋巴结和淋巴管显像分成良好和较差两个等级；记录STIR序列扫描和MR- LG显示的所有淋巴结,并与前哨淋巴结病理对照.结果:80％ (24/30)的荷瘤兔完成第二次MR- LG检查,良好3D图像为79.2％ (19/24).在MR - LG图像上,淋巴结信噪比(SNR)均高于其引流淋巴管和同层肌肉(P值均＜ 0.05),SLN与n-SLN、引流淋巴管与同层肌肉之间的SNR无统计学差异.MR- LG图像上可清晰显示SLN和n-SLN(共26枚)的17只荷瘤兔,其STIR图像上共有28枚淋巴结,且两者淋巴结的大小无明显差异(t=0.124,P=0.902);其SLNB检查获得32枚淋巴结(SLN18枚,n- SLN 14枚),且淋巴结大小与MR- LG图像上和STIR序列扫描所显示的淋巴结无统计学差异.结论:钆剂增强MR-LG可较好地显像VX2兔乳腺癌SLN.

Magnetic Resonance Lymphography for Sentinel Lymph Node Mapping in VX2 Rabbit Breast Cancer

Purpose:To study the feasibility of the interstitial magnetic resonance lymphography(MRLG) by using Gadolinium contrast agent for sentinel lymph node(SLN) mapping in rabbit VX2 breast cancer.Methods:MR - LG exams were completed on 30 New Zealand White Rabbits before and after VX2 tumor being implanted(including pre - contrast STIR sequence scanning).SLN was defined as the first lymph node/ s on the lymphatic drainage pathway,and the imaging quality was classified as good grade(with both SLN and lymphatic drainage pathway presented) and poor grade(either SLN or lymphatic drainage pathway absented).All lymph nodes were recorded on the images of STIR scanning and MR - LG,and then they were compared with the results of SLN pathology.Results:①Of all bearing tumor rabbits,80%(24/ 30) were completed the second MR - LG examinations,and the rate of good grade for 3D imaging was 79.2%(19/ 24)②The SNR of lymph nodes was higher than that of affected lymph duct and muscle after the contrast agent being injected on MR - LG(both P value < 0.05),but there was no difference between SLN and n - SLN,affected lymph duct and muscle.③There were 26 lymph nodes on MR - LG and 28 lymph nodes on STIR scanning in all,but there was no significant difference between the size shown by them(t = 0.124,P = 0.902).(4)A11 17 bearing tumor rabbits with good grade imaging underwent the SLN biopsy,and 18 SLN and 14 n - SLN were got.However,the sizes of SLN, which were obtained from SLN biopsy,MR - LG and STIR,were with no differences.Conclusion:The Gadolinium contrast enhanced MR - LG is useful for the SLN mapping in VX2 rabbit breast cancer.