不同浓度超小超顺磁性氧化铁粒子在兔炎症淋巴结模型中的磁共振强化特征  

Magnetic Resonance Enhancement Features of Inflammatory Lymph Nodes with Ultrasmall Superparamagnetic Iron Oxide in Rabbit Model

作　　者：雷晶[1] 薛华丹[1] 李烁[1] 李琢[1] 金征宇[1] 

机构地区：[1]中国医学科学院北京协和医学院北京协和医院放射科,北京100730

出　　处：《中国医学科学院学报》2009年第2期182-186,共5页Acta Academiae Medicinae Sinicae

基　　金：国家高技术研究发展计划项目(863项目)(2007AA02Z400)~~

摘　　要：目的研究不同浓度超小超顺磁性氧化铁粒子(USPIO)在兔炎性淋巴结中的增强磁共振特征,建立US-PIO淋巴结显像的常规注射及扫描方案。方法12只健康新西兰兔于足垫注射完全弗氏佐剂,建立腘窝淋巴结的炎性增生模型。静脉注射不同剂量(45、90、135μmolFe/kg)的USPIO,注射前后行磁共振扫描,观察不同浓度组及90μmolFe/kg浓度组在不同时间点淋巴结强化特征,测量各组淋巴结T2信号强度、T1信号强度、T2*值及T2值变化并计算T2强化率。结果炎症淋巴结在USPIO增强后24h,90和135μmolFe/kg浓度组T2加权像序列强化效果及强化率差异无显著性,但均显著优于45μmolFe/kg浓度组(P<0.05);90μmolFe/kg组在6～24hT2信号强度、T1信号强度、T2值及T2强化率差异无显著性(P>0.05),90μmolFe/kg组淋巴结信号强度降低在18h达峰值,于18～24h均能获得较好的图像。结论90μmolFe/kg可以较好地强化淋巴结,注射USPIO后18～24h采集淋巴结图像可以达到满意的强化效果。Objective To study magnetic resonance enhancement features of inflammatory lymph nodes using different doses of ultrasmall superparamagnetic iron oxide （USPIO） particles in order to establish a standardized protocol for USPIO enhanced magnetic resonance imaging of lymph nodes. Methods A total of 12 healthy New Zealand rabbits were injected complete Freund＇s adjuvant in foot pad to establish popliteal inflammatory lymph node model. Different doses （45, 90, 135 μmol Fe/kg） of USPIO were injected intravenously. Magnetic resonance scans were performed before and after USPIO injection to observe the enhancement features of different groups. T2 signal intensity, T1 signal intensity, T2 ＊ value, and T2 value were measured and T2 enhancement ratio was calculated at different time points. Results Twenty-four hours after USPIO in jection, there was no statistical difference in T2 signal intensity and T2 enhancement ratio between 90 and 135 μmol Fe/kg dose groups, but both were superior to 45 μmol Fe/kg group （ P 〈 0. 05 ）. There were no statistical differences in T2 signal intensity, T1 signal intensity, T2 value, and T2 enhance ratio among different postcontrast time delays from 6 to 24 hours in 90 μmol Fe/kg group （ P 〉 0.05 ）, and signal reduction of lymph nodes peaked 18 hours after USPIO injection. Better images were acquired with a postcontrast delay of 18-24 hours. Conclusions Lymph nodes can be enhanced well with a dose of 90 μmol Fe/kg. Postcontrast delay of 18-24 hours is appropriate for acquiring satisfactory enhancement images.

关 键 词：超小超顺磁性氧化铁粒子 炎症淋巴结 磁共振成像 

分 类 号：R814.42[医药卫生—影像医学与核医学]