大鼠C6脑胶质瘤超小型超顺磁氧化铁灌注成像与Gd-DTPA灌注成像对比

Comparison of ultrasmall superparamagnetic iron oxide and Gd-DTPA as contrast agents for MR perfusion weighted imaging in rat C6 brain gliomas

目的比较大鼠C6脑胶质瘤超小型超顺磁氧化铁(USPIO)PWI与Gd-DTPA PWI的异同点,观察USPIOPWI评价胶质瘤微血管水平血流灌注的可行性。方法对30只雄性SD大鼠接种C6胶质瘤,并随机分成2组:USPIOPWI组及Gd-DTPA PWI组,于接种后12天行常规MR及PWI扫描,之后行SE T1 W或FSE T2 W增强扫描。于肿瘤最大层面选取ROI,分别于肿瘤强化区及对侧正常脑实质区获取灌注曲线,计算ROI的最大信号强度下降百分比(SRRmax)、相对血流容积(rBV)及肿瘤组织与正常脑组织rBV比值(QrBV)和SRRmax比值(QSRRmax),同时取肿瘤组织行HE及GFAP染色。结果 USPIO PWI组及Gd-DTPA PWI组肿瘤组织rBV和SRRmax值均明显高于对侧正常脑组织(P<0.05)。USPIO PWI组肿瘤组织rBV和SRRmax均高于Gd-DTPA PWI组(P<0.05)。USPIO PWI组与Gd-DTPA PWI组的肿瘤组织与正常脑组织QrBV和QSRRmax值之间差异有统计学意义(P<0.05)。结论与Gd-DTPA PWI相比,USPIO PWI具有更加明显的灌注效应,有助于评估肿瘤微循环。

Objective To compare the similarities and differences between ultrasmall superparamagnetic iron oxide（USPIO） PWI and Gd-DTPA PWI,and to observe the feasibility of USPIO PWI in evaluating tumor angiogenesis.Methods C6 glioma model in 30 male rats were established and divided into two groups in random： USPIO PWI group and Gd-DTPA PWI group.Conventional MR imaging and PWI were performed at 12 days of tumor age.USPIO PWI and Gd-DTPA PWI were performed,respectively.Imaging sequences included SE T1W,FSE T2W,EPI PWI.ROIs at the largest section of tumor were selected in each rat.Perfusion curves of tumors in enhancement areas and contralateral normal brain tissue were obtained,and the maximum signal reduction ratio（SRRmax）,regional blood volume（rBV） and the ratio of each parameter（QrBV,QSRRmax） between the two ROIs were calculated.Histopathology examination was performed with HE staining and immunohistochemistry of GFAP.Results Statistical differences of the rBV and SSRmax were found between tumor tissue and normal brain tissue in both USPIO PWI and Gd-DTPA PWI group（P0.05）.The rBV and SSRmax in USPIO PWI group were higher than those in Gd-DTPA PWI group（P0.05）.Statistical difference of the QrBV and QSRRmax were also found between the two groups（P0.05）.Conclusion USPIO PWI can demonstrate more obvious perfusion effect than Gd-DTPA,therefore being helpful to the evaluation of tumor microcirculation.