Abnormalities in Diffusional Kurtosis Metrics Related to Head Impact Exposure in a Season of High School Varsity Football
Abnormalities in Diffusional Kurtosis Metrics Related to Head Impact Exposure in a Season of High School Varsity Football
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DOI：
10.1089/neu.2015.4267
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发表时间：
2016-12-01
影响因子：
4.2
通讯作者：
Maldjian, Joseph A.
中科院分区：
文献类型：
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作者：
Davenport, Elizabeth M.;Apkarian, Kalyna;Maldjian, Joseph A.
本研究的目的是确定在没有临床诊断的脑震荡的情况下，在高中足球赛季期间累积头部撞击的影响是否会产生弥散峰度成像（DKI）指标的变化。受试者从高中足球队招募，并配备了头部撞击遥测系统（HITS）在所有的做法和游戏。计算生物力学股骨头撞击暴露指标，包括：总撞击、加速度总和和风险加权累积暴露（RWE）。24名球员完成了季前和季后的磁共振成像，包括DKI;经历过临床脑震荡的球员被排除在外。14名受试者完成了季节前和季节后的脑震荡后立即评估和认知测试（ImPACT）。DKI衍生的度量包括平均峰度（MK）、轴向峰度（K轴向）和径向峰度（K径向），白色物质建模（WMM）参数包括轴突水分数、轴突外空间的弯曲度、轴突外扩散率（De轴向和径向）和轴突内扩散率（Da）。这些指标用于确定异常体素的总数，定义为高于或低于组平均值的2个标准差。线性回归分析显示，RWE组合概率（RWECP）和MK之间的统计学显着关系。其他DKI衍生指标和WMM指标的次要分析显示，在协变量调整后，与RWECP存在统计学显著的线性关系。将这些结果与同一队列中相同成像会话的DTI衍生指标的结果进行比较。几个DKI衍生标量（Da，MK，K轴向和K径向）解释更多的变化，与RWECP相比，这表明DKI可能是更敏感的亚震荡头部的影响。未发现DKI衍生指标和ImPACT指标之间存在显着关系。重要的是要注意，这些指标的病理学含义尚未得到很好的理解。总之，我们证明了在没有临床诊断的脑震荡的情况下，高中足球的一个赛季可以产生DKI可测量的变化。
The purpose of this study was to determine whether the effects of cumulative head impacts during a season of high school football produce changes in diffusional kurtosis imaging (DKI) metrics in the absence of clinically diagnosed concussion. Subjects were recruited from a high school football team and were outfitted with the Head Impact Telemetry System (HITS) during all practices and games. Biomechanical head impact exposure metrics were calculated, including: total impacts, summed acceleration, and Risk Weighted Cumulative Exposure (RWE). Twenty-four players completed pre-and post-season magnetic resonance imaging, including DKI; players who experienced clinical concussion were excluded. Fourteen subjects completed pre-and post-season Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). DKI-derived metrics included mean kurtosis (MK), axial kurtosis (K axial), and radial kurtosis (K radial), and white matter modeling (WMM) parameters included axonal water fraction, tortuosity of the extra-axonal space, extra-axonal diffusivity (De axial and radial), and intra-axonal diffusivity (Da). These metrics were used to determine the total number of abnormal voxels, defined as 2 standard deviations above or below the group mean. Linear regression analysis revealed a statistically significant relationship between RWE combined probability (RWECP) and MK. Secondary analysis of other DKI-derived and WMM metrics demonstrated statistically significant linear relationships with RWECP after covariate adjustment. These results were compared with the results of DTI-derived metrics from the same imaging sessions in this exact same cohort. Several of the DKI-derived scalars (Da, MK, K axial, and K radial) explained more variance, compared with RWECP, suggesting that DKI may be more sensitive to subconcussive head impacts. No significant relationships between DKI-derived metrics and ImPACT measures were found. It is important to note that the pathological implications of these metrics are not well understood. In summary, we demonstrate a single season of high school football can produce DKI measurable changes in the absence of clinically diagnosed concussion.