Advantages of QBI in TBSS analyses
Advantages of QBI in TBSS analyses
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DOI：
10.1016/j.mri.2013.09.002
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发表时间：
2014-02-01
影响因子：
2.5
通讯作者：
Esposito, Fabrizio
中科院分区：
文献类型：
--
作者：
Corbo, Daniele;Caiazzo, Giuseppina;Esposito, Fabrizio
弥散加权磁共振成像（DWMRI）用于研究正常和临床人群中的白色物质（WM）。在DWMRI研究中，扩散张量成像（DTI）模拟了具有一个主导方向的WM各向异性，仅在大且高度相干的纤维束中检测可能的通路异常。然而，更一般的各向异性模型，如Q球成像（QBI），可以提供更敏感的WM描述符在单个患者。本研究以肌萎缩侧索硬化症（ALS）作为WM束变性的病理病例模型，对19例ALS患者和19例年龄、性别匹配的健康对照者进行了DWMRI检查，比较了DTI和QBI模型在群体水平的人群分析中的作用。结果：与对照组相比，ALS患者运动和运动外神经纤维的广义各向异性分数（GFA）均显著降低。同源物DTI衍生的FA图与GFA图仅部分重叠。特别是，左皮质脊髓束导致更显着描绘的QBI比DTI模型，与GFA预测ALS残疾优于FA。目前的研究结果表明，QBI模型是适合研究WM束变性在人群水平的临床研究。特别是，当DTI偏向低值时，例如在纤维变性的情况下，以及在具有多于一个主导纤维方向的区域中，纤维完整性的组水平研究可能受益于QBI。(C)2014 Elsevier Inc. All rights reserved.
Diffusion-weighted magnetic resonance imaging (DWMRI) is used to study white matter (WM) in normal and clinical populations. In DWMRI studies, diffusion tensor imaging (DTI) models the WM anisotropy with one dominant direction, detecting possible pathway abnormalities only in large and highly coherent fiber tracts. However, more general anisotropy models like Q-ball imaging (QBI) may provide more sensitive WM descriptors in single patients. The present study aimed to compare DTI and QBI models in a group-level population analysis, using Amyotrophic Lateral Sclerosis (ALS) as a pathological case model of WM tract degeneration.DWMRI was performed in 19 ALS patients and 19 age and sex-matched healthy controls. DTI and QBI estimates were compared in whole-brain tract-based spatial statistics (TBSS) and volume of interest (VOI) analyses, and correlated with ALS clinical scores of disability.A significant decrease of the QBI-derived generalized fractional anisotropy (GFA) was observed in both motor and extramotor fibers of ALS patients compared to controls. Homologue DTI-derived FA maps were only partially overlapping with GFA maps. Particularly, the left corticospinal tracts resulted more markedly depicted by the QBI than by the DTI model, with GFA predicting ALS disability better than FA.The present findings demonstrate that QBI model is suitable for studying WM tract degeneration in population-level clinical studies. Particularly, group-level studies of fiber integrity may benefit from QBI when DTI is biased towards low values, such as in cases of fiber degeneration, and in regions with more than one dominant fiber direction. (C) 2014 Elsevier Inc. All rights reserved.