磁共振扩散峰度成像对大脑灰质核团微观结构发育变化的检测  

Detection of microstructural developmental changes in cerebral gray matter nuclei by diffusion kurtosis imaging

作　　者：孙亲利[1,2] 李贤军 李梦轩[1] 尚进 刘哲[1] 金超[1] 张玉利[1] 刘聪聪 鱼博浪 杨健[1,2] SUN Qinli;LI Xianjun;LI Mengxuan;SHANG Jin;LIU Zhe;JIN Chao;ZHANG Yuli;LIU Congcong;YU Bolang;YANG Jian(Department of Radiology,the First Affiliated Hospital of Xi’an Jiaotong University,Xi’an 710061;Department of Biomedical Engineering,School of Life Science and Technology,Xi’an Jiaotong University,Xi’an 710054,China)

机构地区：[1]西安交通大学第一附属医院医学影像科,西安710061 [2]西安交通大学生命科学与技术学院生物医学工程系,西安710054

出　　处：《磁共振成像》2019年第10期774-778,共5页Chinese Journal of Magnetic Resonance Imaging

基　　金：国家重点研发计划项目(编号：2016Y FC0100300);国家自然科学基金面上项目(编号：81471631,81771810,81171317);2011年教育部“新世纪优秀人才支持计划”项目(编号：NCET-11-0438);陕西省自然科学基金青年项目(编号：2019JQ-198,2017JQ8005);西安交通大学第一附属医院临床研究课题重点项目(编号：XJTU1AF-CRF-2015-004);西安交通大学第一附属医院青年创新基金项目(编号：2011YK.19)~~

摘　　要：目的通过比较磁共振扩散张量参量和扩散峰度参量在检测新生儿与成人大脑灰质核团微观结构变化的差异,探讨磁共振扩散峰度成像(diffusion kurtosis imaging,DKI)技术在脑灰质研究中的意义.材料与方法研究对象为22名足月新生儿(校正胎龄39~44周)和22名成人(年龄18~26岁).应用3.0 T磁共振设备行头颅DKI扫描,b值为0、500、1000、2000和2500 s/mm2,每个非零b值18个梯度磁场方向.通过DKI模型计算出各向异性分数(fractional anisotropy,FA)、平均扩散率(mean diffusivity,MD)、平行扩散率(axial diffusivity,AD)、垂直扩散率(radial diffusivity,RD)、平均扩散峰度(mean kurtosis,MK)、平行扩散峰度(axial kurtosis,AK)和垂直扩散峰度(radial kurtosis,RK).感兴趣区为丘脑、壳核、苍白球和尾状核4个大脑灰质核团.结果与新生儿比较,成人4个大脑灰质核团的FA、MK、AK和RK值升高,MD、AD和RD值降低.除了丘脑的AD(P=0.944)外,新生儿与成人4个灰质核团的FA、MD、AD、RD、MK、AK和RK等7个参量值在两组间差异均有统计学意义(P<0.05).扩散峰度参量MK、AK、RK的相对变化率从82.86%到210.81%,而扩散张量参量FA、MD、AD、RD的相对变化率仅从1.45%到70.59%.结论新生儿与成人大脑灰质核团扩散峰度参量的变化率明显大于扩散张量参量的变化率,扩散峰度参量检测灰质微观结构变化的敏感性更高,磁共振扩散峰度成像具有探索灰质微观结构发育变化的潜力.Objective: To explore the significance of diffusion kurtosis imaging (DKI) technique in the study of gray matter development, this work investigated the differences of diffusion tensor metrics and kurtosis metrics in detecting the microstructural developmental changes from neonates to adults on the cerebral gray matter nuclei. Materials and Methods: Twenty-two term neonates (postmenstrual age of 39-44 weeks) and 22 adults (age of 18-26 years) were included. DKI was performed in a 3.0 T scanner with the following variables: b values=0, 500, 1000, 2000 and 2500 s/mm2;18 gradient directions per nonzero b value. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD), mean kurtosis (MK), axial kurtosis (AK) and radial kurtosis (RK) were calculated by using the DKI model. Four regions of interest (ROIs) of the cerebral gray matter nuclei, including thalamus, putamen, globus pallidus and caudate nucleus, were selected based on the brain atlas. Results: Compared with neonates, FA, MK, AK and RK increased in the four adults gray matter nuclei, while MD, AD and RD reduced. Except AD in thalamus (P=0.944), the mean values of FA, MD, AD, RD, MK, AK and RK in four GM nuclei were statistically different between neonates and adults (P<0.05). The relative change ratios of MK, AK and RK ranged from 82.86% to 210.81%, while those of FA, MD, AD and RD ranged just from 1.45% to 70.59%. Conclusions: The change rates of kurtosis metrics on the gray matter nuclei between neonates and adults were higher than those of diffusion tensor metrics, which suggested that the sensitivity of kurtosis metrics was higher on the detection of microstructural changes on the gray matter nuclei. DKI has the potential to explore the developmental change of gray matter.

关 键 词：磁共振成像 扩散张量成像 扩散峰度成像 大脑灰质核团 

分 类 号：R445.2[医药卫生—影像医学与核医学] R338.2[医药卫生—诊断学]