基于低频振幅算法的屈光参差性弱视自发脑活动研究

目的基于低频振幅(amplitude of low frequency fluctuation,ALFF)算法分析屈光参差性弱视和正常对照组的功能性磁共振成像(functional magnetic resonance imaging,f MRI)图像数据,对比揭示弱视患者脑部自发活动的异常,以及这些异常与弱视视力损失的相关性。方法在闭眼静息条件下采集22例弱视成年人和21例正常对照组f MRI数据,对f MRI数据进行预处理,计算每个被试脑区的ALFF值。应用双样本t检验对ALFF结果进行组间分析,采用皮尔森分析弱视不同脑区的ALFF与其损伤的相关程度。结果在屈光参差性成人弱视与正常组有显著性差异的脑区中,脑部自发活动增加的脑区主要分布在颞下回、颞上回、枕叶等区域,脑部自发活动降低的脑区主要分别在小脑后叶、额下回、额上回等区域。首次发现小脑后叶、楔回、枕叶、颞上回和额叶等区域脑区自发活动与弱视损伤有显著相关性。结论基于低频振幅的静息态磁共振分析是有效的非侵入式脑区同步性异常研究方法,能够反映屈光参差性弱视自发脑部活动脑区异常表现,这些同步性异常表现与视力损失程度有较强的相关性,这些结果对于弱视致病机制模型研究和提出新的治疗方法都有重要启发。

Patterns of spontaneous brain activity in anisometropic amblyopiabased on amplitude of low frequency fluctuation

Objective In resting-state functional magnetic resonance imaging ( fMRI ) study, spontaneous activity patterns abnormally in anisometropic amblyopia can be reflected by the change of amplitude of low frequency fluctuation ( ALFF ) and the correlation between the amplitude of low frequency fluctuation ( ALFF) value and acuity deficit. Methods Twenty two adult anisometropic amblyopes and 21 normal controls participated in this fMRI study. The fMRI data were analyzed to get ALFF value in each subject. Two sample t test was carried out to analysis ALFF value within the whole brain for the inter groups. The correlation between the ALFF value and the amblyopic eye' s visual acuity was calculated as the Pearson correlation coefficient. Results The ALFF value mainly increased inferior temporal gyrus,superior temporal gyrus and occipital lobe, while decreased in cerebellum posterior lobe, inferior frontal gyrus and superior frontal gyrus. Further the changes in ALFF such as cerebellum posterior lobe, precuneus, occipital lobe, superior temporal gyrus and frontal lobe had significant correlation with amblyopia acuity deficit. Conclusions ALFF is an effectivenoninvasive algorithm,which can help to exploring spontaneous patterns changes in amblyopia. And multiple area existed patterns abnormal and some of them may relate to the acuity deficit. These results have important implications for models of amblyopia and approaches to treatment.