SPIO增强MRI成像在大鼠脾脏荷VX2肿瘤模型的实验研究  

Superparamagnetic iron oxide-enhanced magnetic resonance imaging of splenic VX2 tumor in rats

作　　者：阳红艳[1] 许乙凯[2] 吴元魁[2] 刘文源[3] 吕国士[2] 曹国洪[2] 

机构地区：[1]成都军区总医院医学影像科,四川成都610083 [2]南方医科大学附属南方医院医学影像中心,广东广州510515 [3]沈阳军区总医院医学影像科,辽宁沈阳110016

出　　处：《中华肿瘤防治杂志》2008年第2期97-100,共4页Chinese Journal of Cancer Prevention and Treatment

摘　　要：目的:建立大鼠脾脏VX2肿瘤模型,研究大鼠脾VX2肿瘤超顺磁性氧化铁(SPIO)增强MRI上信号强度变化与病理学改变之间的关系。探讨SPIO在大鼠脾脏转移瘤的应用价值。方法:对8只脾脏荷VX2肿瘤模型鼠;静脉注射SPIO后行MRI扫描,扫描序列采用T1WI(450/12ms)和T2WI(4000/128ms)。结果:平扫SET1WI上肿瘤-脾脏的对比噪声比极差,所有病灶均不能很好显示。SPIO增强T2WI上正常脾实质信号强度明显降低,信号强度下降百分比(PSIL)为55.04%;脾脏VX2肿瘤信号强度无明显下降,PSIL为0.87%,与正常脾实质信号强度下降程度差异有统计学意义,t=3.879,P<0.001。脾VX2肿瘤的CNR较增强前显著提高,t=6.963,P<0.001。结论:SPIO增强T1WI上正常脾实质与VX2肿瘤组织的对比差,病灶的检出率低,不利于描述病灶的特征。SPIO增强T2WI上脾脏-肿瘤的对比显著,提高了病灶的检出率,改善了病灶影像学特征的描述。OBJECTIVE：To establish a rodent model of VX2 tumor in the spleen of rats, to analyze the relationship between the changes of the signal intensity on superparamagnetic iron oxide （SPIO） enhanced MRI images and pathologic changes,and to discuss the value of SPIO enhanced MRI in detection of splenic metastase in rats. METHODS： The images of 8 rodent model of VX2 tumor in spleen were obtained before and after the administration of superparamagnetic iron oxide. T1-weighted spin-echo （SE） pulse sequence was obtained with a repetition time （TR） being 450 msec,and echo time （TE） being 12 msec （TR/TE=450/12）. The imaging parameters of T2-weighted SE pulse sequence were as follows： TR/TE= 4 000/128. RESULTS： On plain MRI scanning T1-weighted all lesions were not displayed well. On SPIO enhancement T2WI sequence SI of splenic parachyma decreased obviously with the percentage of signal intensity loss （PSIL） being 55.04% ,but SI of tumor did not evidently change with PSIL being 0. 87%. Nevertheless SNR of normal splenic parenchyma around the lesions had a significant difference, t = 3. 879, P 〈 0. 001, comparatively. Moreover, the contrast-to-noise （CNR） between VX2 tumor and splenic parenchyma had a significant difference before and after the admininstration of SPIO, t= 6.963, P〈 0. 001. CONCLUSIONS： On SPIO enhancement T1 WI sequence the contrast of tumob-tospleen is poor. So it is not good to characterize the lesions in spleen. On SPIO enhanced T2 WI the contrast degree of lesions increases obviously. Consequently, SPIO-enhanced T2 WI MRI scanning can improve the rate of detection and characterization in lesions of spleen.

关 键 词：肿瘤 实验性 磁共振成像 模型 动物 铁化合物 

分 类 号：R733.2[医药卫生—肿瘤]