颈部淋巴结转移和反应性增生的间质磁共振造影表现

An experimental study of IMRLG enhanced by dextran-DTPA-Gd in detecting metastatic and reactively hyperplastic cervical lymph nodes

目的 :探讨颈部淋巴结转移和反应性增生的dextran-DTPA-Gd间质磁共振造影特点。方法 :12只新西兰大白兔随机分为颈部淋巴结反应性增生及颈部淋巴结转移2组模型。建模成功后,行双侧舌缘黏膜下注射dextranDTPA-Gd各0.2 m L,分别于注射后5、15、45、60 min,4、24 h行间质磁共振淋巴造影(interstitial magnetic resonance lymphography,IMRLG)检查,分析其淋巴显影强化程度,计算强化前、后的信号强度(E%),绘制信号强度-时间曲线,并对磁共振图像与病理结果进行比较分析。采用SPSS17.0软件包对数据进行统计学分析。结果:肿瘤组45 min时的信号强度达到峰值(289%),增生组30 min达到峰值(367%),相同时间的信号强化率差异显著(P<0.05)。IMRLG肿瘤组诊断为转移阳性淋巴结24枚,其中,2枚经病理证实为假阳性,阳性诊断率为91.67%(22/24);增生组27枚淋巴结误诊为肿瘤转移5枚,假阳性率为18.5%(5/27)。结论:Dextran-DTPA-Gd间质磁共振造影具有鉴别颈部淋巴结转移和反应性增生的应用价值。

PURPOSE： To investigate the characteristics of metastatic and reactively hyperplastic lymph nodes in interstitial magnetic resonance lymphography enhanced by dextran-DTPA-Gd. METHODS： Twelve New Zealand white rabbits were divided into 2 groups at random ：reactive hyperplasia group and tumor group. 0.2 m L dextran-DTPA-Gd was injected into the bilateral submucosa of the tongue in 12 New Zealand rabbits. Then the MR images by using 3-D enhancement magnetic resonance lymphography at 5, 15, 30, 45, 60 mins and 4, 24 h after injection were obtained. The signal intensities after enhancing were measured to calculate the enhanced rates（E%） of lymph nodes at the same time and the signal enhancing rates-time curve was drawn. The images were analyzed with pathological results.The data were analysed using SPSS17.0 software package. RESULTS： The signal of the tumor group reached a peak after 45 min with E% of 289% and the signal of reactive hyperplasia group reached a peak after 30 min with E% of 367%. The difference of enhancing rates between the metastatic lymph nodes and reactively hyperplastic lymph nodes was significant at the same time（P〈0.05）. In tumor group, 24 lymph nodes were diagnosed as metastatic lymph nodes by IMRLG with 2 false positivity;while 91.67%（22/24） metastatic lymph nodes were confirmed by pathological diagnosis. In the reactive hyperplasia group,5lymph nodes were misdiagnosed as metastatic lymph nodes by IMRLG and the false-positive rate was 18.5%（5/27）.CONCLUSIONS： IMRLG enhanced by dextran-DTPA-Gd could effectively detect metastatic and reactively hyperplastic cervical lymph nodes.