K空间填充策略对基于FLASH序列的APT图像脂肪伪影的影响  

The Impact of K-Space Filling Strategy on Fat Artifacts in APT Imaging Based on FLASH Sequence

作　　者：逄奇凡 王志超 武玉朋 李建奇[1] PANG Qifan;WANG Zhichao;WU Yupeng;LI Jianqi(Shanghai Key Laboratory of Magnetic Resonance,School of Physics and Electronic Science,East China Normal University,Shanghai 200062,China;Zhejiang Lab,Hangzhou 311100,China)

机构地区：[1]华东师范大学物理与电子科学学院,上海市磁共振重点实验室,上海200062 [2]之江实验室,浙江杭州311100

出　　处：《波谱学杂志》2024年第4期443-453,共11页Chinese Journal of Magnetic Resonance

基　　金：华东师范大学“幸福之花”基金资助项目.

摘　　要：在化学交换饱和转移(CEST)成像实验中,由于信号采集过程中纵向磁化矢量的弛豫恢复,实际采集信号的CEST对比度呈持续衰减状态,因此,CEST分段饱和模式以及对应的K空间填充方法会对CEST的图像质量和定量结果产生不同的影响.本文通过仿真和人体实验,探究了快速小角度激发(FLASH)序列中不同K空间填充策略对颅脑酰胺质子转移(APT)成像质量以及APT对比度的影响.研究结果显示,采用分段饱和与重排优化K空间中心优先填充技术,可有效消除皮下脂肪导致的伪影,并提高APT非对称分析获取非对称性磁化转移率MTRasym的准确性.In chemical exchange saturation transfer(CEST)imaging,the relaxation recovery of longitudinal magnetization during the signal acquisition process results in a decrease in CEST contrast.Consequently,the CEST saturation mode and the corresponding K-space filling method significantly influence both the image quality and quantitative results of CEST.In this paper,simulations and human experiments were conducted to examine the impact of various K-space filling strategies within the fast low angle shot(FLASH)sequence on the quality of brain amide proton transfer(APT)images and on the quantitative analysis of magnetization transfer ratio asymmetry(MTRasym).The result indicates that employing segmented saturation techniques with optimized reordered center-out K-space filling technology can effectively mitigate artifacts caused by scalp fat and enhance the accuracy of MTRasym values.

关 键 词：磁共振成像(MRI) 化学交换饱和转移(CEST) 脂肪伪影 分段采集 K空间重排 

分 类 号：O482.53[理学—固体物理]