基于扩散加权成像的表观纤维密度重测信度研究  

The Test-Retest Assessment of Apparent Fiber Density Measurements Using Diffusion Weighted Imaging in English

作　　者：骆义超 严经国 陈元园 范秋筠 Luo Yichao;Yan Jingguo;Chen Yuanyuan;Fan Qiuyun(School of Precision Instruments and Optoelectronics Engineering,Tianjin University,Tianjin 300072,China;Tianjin Key Laboratory of Brain Science and Neural Engineering,Tianjin 300072,China;Academy of Medical Engineering and Translational Medicine,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学精密仪器与光电子工程学院,天津300072 [2]天津市脑科学与神经工程重点实验室,天津300072 [3]天津大学医学工程与转化医学研究院,天津300072

出　　处：《中国生物医学工程学报》2023年第4期420-430,共11页Chinese Journal of Biomedical Engineering

基　　金：国家自然科学基金(82071994)。

摘　　要：扩散加权成像已广泛应用于人脑白质组织的量化研究。表观纤维密度(AFD)是基于纤维取向分布函数(FOD)的量化指标,可以反映白质组织纤维相对密度,在健康发育和退行性神经系统疾病研究中已得到初步应用。然而,AFD的测量高度依赖实验参数设置,其在不同实验条件下的重测信度尚未有系统性评估。本研究采用人脑连接组计划(HCP)和Connectome Diffusion Microstructure Dataset(CDMD)两个独立数据集中共42位受试者的两次重复实验数据,通过基于纤维束单元的分析(FBA)方法计算纤维束单元(fixel)水平的AFD值,采用TractSeg进行纤维束分割,计算纤维束平均AFD,研究AFD在不同扩散加权值(b值)条件下的重测信度。结果显示,对于HCP数据集中的数据(n=35),在fixel水平上,AFD检测值在两次重复实验间的皮尔逊相关系数(r)和组内相关系数(ICC)随着b值增加,分别从0.7969和0.8985升高至0.8828和0.9414,绝对偏差从0.1241减小至0.1073。对于CDMD数据集中的数据(n=7),也存在相似的变化趋势。在纤维束平均水平上,两个数据集中的AFD值在各b值条件下均具有较高可重复性。本研究评估了b值在1000~5000 s·mm^(-2)范围内AFD检测值的可重复性,有望为AFD测度在未来神经生物学应用研究中提供实验设计参考依据。Diffusion weighted imaging has been widely used in quantitative study of human brain white matter.Apparent fiber density(AFD)is a quantitative metric based on the fiber orientation distribution(FOD),which can reflect the fiber density of white matter and has been applied in the research of healthy development and neurodegenerative diseases.However,the value of AFD measurement strongly depends on experimental set-up,and the test-retest repeatability of AFD under different experimental conditions has not been systematically assessed.In this paper,the test-retest repeatability of AFD was examined at different diffusion weighted values(b-values)using the scan-rescan data of 42 subjects from two separate datasets.One dataset(n=35)is from Human Connectome Project(HCP),the other(n=7)is form Connectome Diffusion Microstructure Dataset(CDMD).The AFD value of fixel level was estimated using fixel-based analysis(FBA),and tract ROIs were obtained using TractSeg to estimate the fiber bundle averaged AFD.Results showed that at the fixel level,as the b-value increased,the Pearson's correlation coefficient(r)and intraclass correlation coefficient(ICC)increased from 0.7969 and 0.8985 to 0.8828 and 0.9414 respectively in the test-retest experiment with HCP,and the absolute deviation decreased from 0.1241 to 0.1073.Similar trend was also found in the dataset from CDMD.At the tract-average level,the test-retest repeatability can be achieved at all b-values in both datasets.In summary,this paper examined the repeatability of AFD estimation for b-values in the range of 1000~5000 s·mm^(-2),and our results might provide useful insights into the experimental design in future neurobiological investigations using AFD.

关 键 词：表观纤维密度 扩散加权成像 组内相关系数 重测信度 

分 类 号：R318[医药卫生—生物医学工程]