均匀性校正在颅脑定量磁化率成像中的应用价值评估  

Effect of signal intensity inhomogeneity correction on quantitative susceptibility mapping of brain

作　　者：甘凤玲 瞿筝 赵玮玮 钟昊东 李改英 李建奇[1] GAN Fengling;QU Zheng;ZHAO Weiwei;ZHONG Haodong;LI Gaiying;LI Jianqi(Shanghai Key Laboratory of Magnetic Resonance,School of Physics and Electronic Science,East China Normal University,Shanghai 200062,China;West China School of Medicine/West China Hospital,Sichuan University,Chengdu 610041,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]四川大学华西临床医学院/华西医院,成都610041

出　　处：《磁共振成像》2022年第4期94-99,共6页Chinese Journal of Magnetic Resonance Imaging

基　　金：国家社会科学基金(编号:15ZDB016)。

摘　　要：目的评估颅脑定量磁化率成像(quantitative susceptibility mapping,QSM)中线圈选择和空间均匀性校正对深部核团磁化率测量值的影响。材料与方法在2.89 T磁共振成像系统上采用20通道和64通道头颈联合线圈完成10名健康受试者扫描,得到分别施加和未施加空间均匀性校正的图像数据,再进行QSM重建。在重建得到的定量磁化率图上,手动勾画出六个双侧脑深部灰质核团,包括红核、黑质、苍白球、壳核、尾状核和齿状核,计算核团内磁化率平均值。采用配对样本t检验、线性相关分析和Bland-Altman分析比较均匀性校正前后、不同通道线圈采集获得的磁化率值的组间差异性和一致性。结果用于QSM重建的图像数据施加空间均匀性校正后,磁化率图上大脑深部核团边界更加清晰,定量磁化率测量值均显著增加。均匀性校正前、后核团内磁化率平均值线性相关(20通道:斜率K=1.06,R^(2)=0.96;64通道:斜率K=1.12,R^(2)=0.95)。在20通道和64通道线圈中采集得到核团内磁化率平均值线性相关(校正前:斜率K=0.92,R^(2)=0.96;校正后:斜率K=0.98,R^(2)=0.96)。配对样本t检验结果显示均匀性校正后64通道和20通道线圈采集的核团磁化率平均值差异无统计学意义。Bland-Altman图显示均匀性校正后64通道和20通道线圈采集方法之间没有明显的偏差。结论线圈选择和空间均匀性校正的使用对颅脑定量磁化率值有一定的影响,采用空间均匀性高的图像可提高QSM测量的准确性。Objective:To evaluate the effects of coil selection and signal intensity inhomogeneity on the susceptibility values of deep gray matter nuclei measured by quantitative susceptibility mapping(QSM).Materials and Methods:Ten healthy subjects were scanned on a 2.89 T MRI system using 20-and 64-channel combined head-neck coils.QSM reconstructions were performed before and after correcting signal intensity inhomogeneity of the original gradient-echo images,respectively.Six bilateral deep cerebral gray matter nuclei were manually drawn on susceptibility maps,including red nucleus,substantia nigra,globus pallidus,putamen,caudate nucleus,and dentate nucleus.Paired sample t test,linear correlation analysis and Bland-Altman analysis were used to compare the differences and consistency of susceptibility values between groups with and without intensity inhomogeneity correction using different coils.Results:The susceptibility maps with intensity inhomogeneity correction demonstrated improved boundaries of deep gray matter nuclei and susceptibility values increased significantly.The mean susceptibility values of deep gray matter nuclei after correction were highly correlated with those before correction(20-channel:slope K=1.06,R;=0.96;64-channel:slope K=1.12,R^(2)=0.95).The mean susceptibility values of deep gray matter nuclei from 20-channel coil were highly correlated with those from 64-channel coil(without correction:slope K=0.92,R^(2)=0.96;with correction:slope K=0.98,R^(2)=0.96).There was no statistically significant difference in the mean susceptibility values between the 20-and 64-channel coils acquisition after correcting the intensity inhomogeneity.Bland-Altman results showed no significant deviation between the 20-and 64-channel coils acquisition after the correction on the intensity inhomogeneity.Conclusions:The signal intensity inhomogeneity affects the susceptibility values of the deep brain nuclei,and inhomogeneity correction can improve the accuracy of susceptibility values of deep gray matter nuclei.

关 键 词：定量磁化率成像 空间均匀性 线圈 深部灰质核团 磁共振成像 

分 类 号：R445.2[医药卫生—影像医学与核医学]