目的 比较右旋糖酐-二乙烯三胺五乙酸钆离子螯合物(dextran-DTPA-Gd)和马根维显两种对比剂在间质MRI淋巴造影中淋巴显影的价值。方法 选择健康成年新西兰兔12只，体重为2.7～3.7kg。仰卧位固定兔，经3D TOF CE-MRA序列扫描，平扫后右侧后肢第1、2、3趾蹼间隙注
射dextran-DTPA-Gd 各0.4ml(3.96×10^-3mol/L)，共1.2ml；30min后左侧后肢第1、2、3趾蹼间隙注射马根维显各0.4ml(0.4998mol/L)，共1.2ml，行MR增强扫描，扫描间隔分别为10、15、20、25、30、35、40、45、50、55、60min、2h、4h、24h。平扫和增强扫描的相关参数相同。分析不同
时间段淋巴显影强化程度，测量并计算腘窝淋巴结增强前后的信号强度(E%)，绘制其信号强度-时间曲线，比较两种显影剂对淋巴显影的区别。结果 平扫时双侧腘窝淋巴结均呈等信号。右侧dextran-DTPA-Gd注射后10min，引流区后肢淋巴管及腘窝淋巴结信号强化明显、显示清晰，腘窝
淋巴结E%为212.7%，35min左右达到峰值，E%值为314.1%，4h后为208.2%，24h后扩清。左侧马根维显注射10min时，引流区域后肢血管强化明显，造影剂大部分吸收入血管进入膀胱，后肢淋巴管及腘窝淋巴结信号弱，腘窝淋巴结E%为78.8%，20min左右达到峰值，E%值为98.3%，4h后减至
29.0%，24h后扩清。淋巴结E%经统计学分析差异有统计学意义(P<0.05)。实验前后动物的生化检查等数据未见异常变化，其差异无统计学意义(P>0.05)，送检的内脏器官组织学检查未见明显的病理学改变。结论 相比马根维显小分子造影剂，dextran-DTPA-Gd是一种有效的淋巴造影剂，
能够特异性靶向强化淋巴结及淋巴管。

Objective To compare the feasibility of interstitial magnetic resonance(MR) lymphography using subcutaneous injection of dextran-DTPA-Gd and gadopentetate dimeglumine. Methods The 1.2ml dextran-DTPA-Gd (3.96×10^-3 mol/L) was injected subcutaneously
into the interdigital skin fold of the dorsal aspect of the right hind leg in 12 New Zealand rabbits. The 1.2ml gadopentetate dimeglumine(0.4998mol/L) was injected into the left hind leg in the same rabbit after 30 minutes. MR images were obtained before
injection and at 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60 minutes and 2,4,24 hours after injection by the 3D TOF CE-MRA sequence.The signal intensities of popliteal lymph node were measured, the enhancing rates(E%) were calculated and the signal-time course
curve was drawn. Results The bilateral popliteal lymph node showed the same signal intensities. The lymphatic vessels in the right hind limb drainage area and popliteal lymph node were strengthened significantly and the E% of popliteal lymph node was
212.7% at 10 min after injecting dextran-DTPA-Gd, reached the peak(314.1%) by 35min, was 208.2% at 4 hours and disappeared 24 hours later. The signal intensities of the left lymphatic and popliteal lymph node were weak and the E% of popliteal lymph node
was 78.8% 10 min after injecting gadopentetate dimeglumine, reached the peak(98.3%) by 20min, was 29.0% 4 hours, and disappeared 24 hours later. The E% was statistically significant (P<0.05). Animals in each group during the observation period were no significant
adverse reactions, biochemical examinations were not statistically significant (P>0.05). Histological examination of the injected organs showed no obvious pathological changes. Conclusion Compared with small molecular gadopentetate dimeglumine, the dextran-DTPA-Gd
is an effective lymphatic contrast agent, which can specific strengthen the lymph nodes and lymphatic.