基于7.0T磁共振用MT成像新方法探究NOE及APT加权成像

发布时间：2018-04-27 11:35

本文选题：神经胶质瘤 + 磁共振成像　；参考：《中国临床医学影像杂志》2017年10期

【摘要】：目的 :磁化传递效应成像是一种新的磁共振成像技术,是目前分子影像学领域的热门研究方向,核奥氏效应(Nu鄄clear overhauser enhancement,NOE)以及酰胺质子转移(APT)是两种特殊的MT成像方法。本研究在7.0T磁共振上探究NOE及APT加权成像。方法:将生鸡蛋清、胎牛血清白蛋白(BSA)、柠檬汁置于试管,将C6胶质瘤细胞接种至大鼠右侧基底节区,7.0T磁共振扫描仪在连续波预饱和下的PRESS序列用不同的预饱和能量进行扫描,射频能量分别为0.6、0.8、1.0、1.3、1.6、2.0、3.0μT。同时用连续被预饱和下的EPI序列扫描出正常鼠以及胶质瘤大鼠的MT图。以上偏置频率为5~-5 ppm,其中扫描参数:TR 6 000 ms,TE 26.51 ms,RF持续时间为4 s。结果 :生鸡蛋清以及BSA均可以观察到比较明显的NOE及APT效应,而柠檬汁则观察不到NOE效应,只能观察到APT效应。且随着能量的增大,APT效应明显增强,而NOE效应明显减弱;在RF预饱和能量1.0μT时,NOE效应相对较大,而APT效应相对较小,当能量1.0μT时则表现为相反的结果。对于大鼠而言,表现为相同趋势。NOE及APT加权图(NOER及APTR)提示大鼠胶质瘤肿瘤中心区域NOE效应下降,APT效应增强。结论:NOE及APT的观察需要较恰当的参数,其中预饱和能量的大小对两种效应的影响较大。太小及太大的预饱和能量都会影响两种效应。本实验首先证实了富含蛋白质的物质可以观测到两种效应,并且观测到胶质瘤大鼠肿瘤区域NOE效应下降而APT效应增强,从而猜测肿瘤区域的效应变化可能与蛋白质分子的浓度有关。
[Abstract]:Objective: magnetization transfer effect imaging is a new magnetic resonance imaging technology and is a hot research direction in the field of molecular imaging at present. Nu-clear overhauser enhancement effect (NOEO) and amide-proton transfer tomography (APT) are two special MT imaging methods. This study explored NOE and APT weighted imaging on 7. 0 T MRI. Methods: raw egg white, fetal bovine serum albumin (BSA) and lemon juice were placed in test tube. C6 glioma cells were inoculated into the right basal ganglia of rats by 7.0T magnetic resonance scanner. The PRESS sequences under continuous wave presaturation were scanned with different presaturation energies. The RF energy is 0.6U 0.81.0U 1.3C 1.6U 2.0 渭 T. At the same time, MT images of normal and glioma rats were scanned by continuous presaturated EPI sequence. The above bias frequency is 5 ~ 5 ppm, and the RF duration of the scan parameter is 4 s. The scan parameter is: TR 6 000 Ms ~ (-1) te 26.51 Ms ~ (-1). Results: the effects of NOE and APT were observed in egg white and BSA, but NOE effect was not observed in lemon juice, but only APT effect was observed in lemon juice. With the increase of energy, the apt effect is obviously enhanced, while the NOE effect is obviously weakened, and when the RF presaturation energy is 1.0 渭 T, the Noe effect is relatively large, while the APT effect is relatively small, and the opposite result is observed when the energy is 1.0 渭 T. For the rats, the same trend. Noe and APT weighted map suggested that the NOE effect in the central region of glioma decreased and the apt effect was enhanced. Conclusion the observation of the ratio of no and APT requires more appropriate parameters, and the magnitude of presaturation energy has a great influence on the two effects. Too small and too large presaturation energy can affect both effects. Two effects can be observed by protein-rich substances, and the NOE effect is decreased and the APT effect is enhanced in glioma rats. Therefore, it is speculated that the change of effect in tumor area may be related to the concentration of protein molecules.
【作者单位】：汕头大学医学院第二附属医院放射科;
【基金】：国家自然科学基金重点项目(编号:30930027)
【分类号】：R445.2

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