肝硬化患者肝移植手术前后静息态脑fMRI低频能量振幅研究

Amplitude of low frequency fluctuations abnormalities in liver cirrhosis patients before and after liv-er transplantation： a resting-state fMRI study

目的 以静息态脑fMRI（rs-fMRI）低频能量振幅（ALFF）方法研究肝硬化患者肝移植手术前后局部脑功能的变化.方法 将准备进行肝移植手术的肝硬化患者11例纳入肝移植组,将健康体检者11例纳入对照组,手术前1周及手术后1月分别进行rs-fMRI检查,健康体检者的检查同期进行.设备采用飞利浦1.5双梯度磁共振成像扫描仪（Philips Achieva 1.5T MRI）,数据预处理基于Matlab7.11（2010b）软件平台,采用REST软件计算ALFF.被试组间比较采用独立样本t检验,结果以多重比较校正后P〈0.05为差异有统计学意义,采用Xjview8.1软件和REST显示结果.结果 （1）与对照组相比,术前肝移植组患者双侧枕中回（MNI：x=36,y=-72,z=9）、双侧楔前叶/楔叶/后扣带回（MNI：x=15,y=-66,z=24）、左侧顶下小叶（MNI：x=-39,y=-54,z=42）、双侧旁中央小叶/扣带中回（MNI：x=3,y=-36,z=45）ALFF值显著减低,未见ALFF显著升高区域;（2）与术前肝移植相比,术后肝移植组患者未见ALFF显著减低或增高区域.将阈值设为P〈0.01（未校正,簇〉10个体素）后,术后肝移植组患者右侧额中回（MNI：x=35,y=57,z=0）、左侧顶下小叶（MNI：x=-39,y=-51,z=42）、扣带回（MNI：x=3,y=-33,z=42）ALFF值升高,未见ALFF显著减低区域;（3）与对照组相比,术后肝移植组患者双侧楔前叶/后扣带回、左侧枕中回ALFF值显著减低,未见ALFF显著升高区域.结论 肝硬化患者视觉功能活动相关区域、DMN相关区域、顶上小叶神经元自发活动强度减弱;肝移植组患者手术后较手术前右侧额中回、左侧顶下小叶、扣带回表现出ALFF值升高的趋势;肝硬化患者接受肝移植手术一个月后,BA7、BA31相关功能区域以及DMN相关区域神经元自发低频振荡活动强度仍未完全恢复正常.

Objective To investigate regional activity abnormalities of patients with liver cirrhosis before and after liver transplantation using resting-state fMRI and amplitude of low frequency fluctuations （ALFF）method.Methods Totally 11 patients preparing to accept liver transplantation were adopted into liver cirrhosis group and 11 healthy volunteers in the health examination were adopted into the control group. The liver cirrhosis group was investigated at a week before operation and repeatedly a month after liver trans-plantation.Healthy volunteers were investigated at the same time.MR imaging data were obtained from a Phil-ips Achieva 1.5-T MR imager.The imaging data were mainly preprocessed with a MATLAB toolbox called DPARSF.REST software was used to calculate the ALFF value of each subject.A second-level random-effect two-sample t-test was performed on the individual ALFF.Significant differences were set at the standard of a corrected cluster level of P〈0.05,and software Xjview 8.1 was adopted to express the outcome.Results （1）Compared with control group,decreased ALFF were found in bilateral middle occipital gyrus（MOG） （MNI：x=36,y=-72,z=9）,bilateral precuneus/cuneus（PCu/Cu）/posterior cingulated（PCC）（MNI：x=15,y=-66,z=24）,left inferior parietal lobule（LIPL）（MNI：x=-39,y=-54,z=42）,and bilateral para-central lobule/cingulate gyrus（MNI：x=3,y=-36,z=45）of cirrhosis patients,no increased ALFF were found.（2）Compared with cirrhosis patients,no increased or decreased ALFF were found in postoperative group.After relaxing standards of statistics,increased ALFF were found in left inferior parietal lobule（IPL） （MNI：x=-39,y=-51,z=42）,cingulate gyrus（MNI：x=3,y=-33,z=42）,and right middle frontal gyrus （MNI：x=35,y=57,z=0）of postoperative group,no decreased ALFF were found.（3）Compared with control group,decreased ALFF were found in bilateral precuneus/posterior cingulated（PCC）,and left middle occipi-tal gyrus（MOG）of postoperative group,no increased ALFF were found.Conclusions Significant decreased ALFF is found in visual cortex（PCu）,DMN（（PCu/Cu/PCC）,and LIPL of cirrrhosis patients,and those ab-normalities reflect the weakness of local neurons spontaneous low-frequency.Compared with beforeoperative group,ALFF of LIPL,in cingulate gyrus,and right middle frontal gyrus have a tendency of rising.One month after liver transplantation,decreased ALFF is found in BA7 and BA 31,suggesting that the spontaneous low-frequency of local neurons haven＇t recoverd to normal level.