An Experimental Study Of IMRLG Enhanced By Dextran-DTPA-Gd In Detecting Metastatic And Reactively Hyperplastic Cervical Lymph Nodes

PURPOSE: To investigate the characteristics of metastatic and reactively hyperplastic lymph nodes enhanced by Dextran-DTPA-Gd in the interstitial magnetic resonance lymphography(IMRLG).METHODS: 12 new zealand white rabbits were divided into 2 groups at random:reactive hyperplasis group and tumor group. VX2 tumor tissues were transplanted to the left ventral submucosa of the tongue. Liquid egg yolk(1 : 1) were injection into the left masseter of the rabbits.0.2m L dextran-DTPA-Gd was injected into the bilateral submucosa of the tongue in12 New Zealand rabbits. Then the MR images by using 3D 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 same time and the signal enhancing rates—time curve was drawn. The images were analyzed with pathological results. The data were analysed by using SPSS17.0software package.RESULTS: The signal of the tumor group reached a peak after 45 min with E% to 289% and the signal of reactive hyperplasis group re ached a peak after 30 min with E% to 367%.The difference of enhanc ing rates between the metastatic lymph nodes and reactively hyperplast ic lymph nodes was significant at the same time(P﹤0.05). In the tu mor group, 24 lymph nodes were diagnosed as the metastatic lymph nodes by IMRLG with 2 false positive;while the 91.67%(22/24) met astatic lymph nodes were affirmed by pathological diagnosis. In the r eactive hyperplasis group,5 lymph nodes were misdiagnosed as the me tastatic lymph nodes by IMRLG and the false-positive rate was 18.5%(5/27).CONCLUSIONS: IMRLG enhanced by dextran-DTPA-Gd could effecti vely detecte the cervical lymph nodes. It also provide brief evidence in diagnosing the metastatic and reactively hyperplastic cervical lymph n odes.