经组织间隙注射Dextran Gd-DTPA兔腘窝淋巴结MRI——一种新型MR对比剂的初步应用  

Initial Experience of MR Lymphography in Rabbits with Injection of a New Contrast Medium(Dextran Gd-DTPA) into Interstitial Space of Popliteal Fossa

作　　者：杨炼[1] 柳熙[1] 徐海波[1] 焉国平[2] 韩萍[1] 

机构地区：[1]华中科技大学附属协和医院放射科,武汉430022 [2]武汉工程大学材料系,武汉430060

出　　处：《放射学实践》2009年第9期971-975,共5页Radiologic Practice

基　　金：国家自然科学基金资助项目(NO.30672067;30700190);教育部新世纪优秀人才资助计划(NCET-07-318)

摘　　要：目的:经组织间隙注射Dextran Gd-DTPA行兔腘窝淋巴结MR成像,探讨该新型淋巴靶向对比剂在鉴别良、恶性淋巴结病变中的价值。方法:选取22只新西兰大白兔,分成Dextran Gd-DTPA增强组和Gd-DTPA对照组,其中增强组18只,对照组4只。增强组分为3个小组:①反应正常组6只;②反应增生组6只,于双侧兔腓肠肌注射蛋黄乳胶;③肿瘤转移组6只,于双侧兔腓肠肌注射VX2肉瘤细胞混悬液。增强组行MRI平扫后,再经双侧趾蹼间隙注射10μmolGd/kg Dextran Gd-DTPA后30 min及1、3、6、12和24 h行腘窝淋巴结脂肪抑制T1WI扫描,测量标准化信号强度(SI)及增强率(En%),描绘浓度-信号强度曲线及时间-增强相应曲线。Gd-DTPA对照组4只,平扫后再经双侧趾蹼间隙注射50μmol Gd/kg Gd-DTPA后5、10和20 min行腘窝淋巴结脂肪抑制T1WI扫描。同时在体外检测Dextran Gd-DTPA溶液中质子的自旋-晶格弛豫时间T1,并计算R1值。结果:Dextran Gd-DTPA的T1值约0.03556 s,R1值约33.37 l/(mmol.s),Dextran Gd-DTPA经趾蹼间隙行腘窝淋巴结成像的达峰时间约1 h,正常组及反应增生组淋巴结均表现为明显强化,信号可均匀,亦可不均匀;VX2肉瘤转移性淋巴结表现为强化不明显,信号可为环状、不规则偏心缺损等不均匀的强化模式,类似邻近肿瘤的强化特征。定量分析发现,VX2肉瘤转移性淋巴结在脂肪抑制T1WI上的标准化SI和强化率(E%)2个指标均明显低于正常组和反应性增生组。在最佳达峰点,正常组Dextran Gd-DTPA的增强率远高于Gd-DTPA对照组。结论:Dextran Gd-DTPA作为组织间隙淋巴靶向对比剂,用量小,强化效应明显,可以鉴别良恶性淋巴结病变。Objective：MR lymphography of popliteal lymph nodes was performed by injection of Dextran Gd-DTPA into interstitial space,to evaluate the value of this new target-oriented contrast agent in the differential diagnosis of benign/malignant lymph nodes.Methods：22 New Zealand rabbits were chosen and divided into Dextran Gd-DTPA enhanced group（18 raabbits） and Gd-DTPA enhanced group（4 rabbits） as control.The rabbits of Dextran Gd-DTPA group were further divided into normal group（6 rabbits）、reactive proliferation group（6 rabbits） with yolk-jel injected into bilateral gastrocnemius muscles,tumor metastases group（6 rabbits） with VX2 sarcoma cells emulsion injected into bilateral gastrocnemius muscles.The Dextran Gd-DTPA enhanced group had plain MR imaging,then 10umol Gd/kg Dextran Gd-DTPA were injected.T1-weighted fat-suppressed SE sequences of the popliteal lymph nodes were performed 30min,1h,3h,6h,12h and 24h after the injection.Standardized signal intensities（SI） and enhanced rate（en %） were measured;SI concentration curve and time-enhancement correlation curve were made.For the control（Gd-DTPA injection） group（4 rabbits）,after plain MRI,50umol Gd/kg Gd-DTPA was injected into bilateral inter-web space and T1-weighted fat-suppressed SE sequences of the popliteal lymph nodes were performed 5,10,20min after injection of contrast.The T1 value（T1） and relaxation rate（R1） of proton in Dextran Gd-DTPA and Gd-DTPA solution were calculated in vitro.Results：T1 of Dextran Gd-DTPA was 0.03556s and R1 was 33.37l/（mmol·s）.The peak of Dextran Gd-DTPA accumulating in popliteal lymph nodes was 1h.For normal and reactive proliferation groups,lymph nodes showed obvious enhancement with homogeneous/heterogeneous signal intensities;yet enhancement in metastatic lymph nodes were mild with ring-like or irregular eccentric defect of enhancement,which were similar to that of the adjacent primary tumor.By quantitative analysis,the standardized SI and En% of VX2 sarcoma metastatic lymph nod

关 键 词：组织间隙 淋巴结 对比剂 磁共振成像 

分 类 号：R445.2[医药卫生—影像医学与核医学]