1 Department of Neurosurgery, Jefferson Integrated Magnetic Resonance Imaging Center, Department of Radiology, Thomas Jefferson University , Philadelphia, Pennsylvania.
2 Department of Radiology, Jefferson Integrated Magnetic Resonance Imaging Center, Department of Radiology, Thomas Jefferson University , Philadelphia, Pennsylvania.
J Neurotrauma. 2018 Feb 1;35(3):452-460. doi: 10.1089/neu.2017.5174. Epub 2017 Dec 18.
The aim of this study is to assess the utility and effectiveness of diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) of the entire pediatric cervical and thoracic spinal cord toward discrimination of typically developing (TD) controls and subjects with spinal cord injury (SCI). A total of 43 pediatric subjects, including 23 TD subjects ranging in age from 6 to 16 years old and 20 subjects with SCI ranging in age from 7 to 16 years, were recruited and scanned using a 3.0 Tesla magnetic resonance scanner. Reduced field of view diffusion tensor images were acquired axially to cover the entire spinal cord across two slabs. For DTI analysis, motion correction was performed by coregistration of the diffusion-weighted images to the reference image (b0). Streamline deterministic tractography results were generated from the preprocessed data. DTI and DTT parameters of the whole cord, including fractional anisotropy (FA), mean diffusivity (MD), tract length, and tract density, were calculated, averaged across the whole spinal cord, and compared between the TD and SCI groups. Statistically significant decreases have been shown in FA (TD = 0.46 ± 0.11; SCI = 0.37 ± 0.09; p < 0.0001) and tract density (TD = 405.93 ± 243.84; SCI = 268.90 ± 270.34; p < 0.0001). However, the mean length of tracts and MD did not show significant differences. When investigating differences in DTI and DTT parameters above and below the injury site, it was shown that the FA and tract density in patients with cervical SCI decreased significantly in the thoracic region. An identical trend was observed in the cervical region for patients with thoracic SCI as well. When comparing TD and SCI subjects, FA and tract density were the most sensitive parameters in detecting functional changes of the spinal cord in chronic pediatric SCI. The results show that both DTI and DTT have the potential to be imaging biomarkers in the diagnosis of SCI.
本研究旨在评估弥散张量成像（DTI）和弥散张量纤维束示踪成像（DTT）在整个儿科颈椎和胸段脊髓中的效用和有效性，以区分正常发育（TD）对照者和脊髓损伤（SCI）者。共招募了 43 名儿科受试者，包括 23 名年龄在 6 至 16 岁的 TD 受试者和 20 名年龄在 7 至 16 岁的 SCI 受试者，并使用 3.0T 磁共振扫描仪对其进行扫描。采集了轴向的小视野弥散张量图像，以覆盖两个层面的整个脊髓。用于 DTI 分析，通过将弥散加权图像与参考图像（b0）配准来进行运动校正。从预处理数据中生成了确定性的流线追踪结果。计算了整个脊髓的弥散张量和弥散张量纤维束示踪成像参数，包括各向异性分数（FA）、平均弥散度（MD）、束长和束密度，并在整个脊髓上进行平均，然后在 TD 组和 SCI 组之间进行比较。结果显示，FA（TD=0.46±0.11；SCI=0.37±0.09；p<0.0001）和束密度（TD=405.93±243.84；SCI=268.90±270.34；p<0.0001）均显著降低。然而，束长和 MD 的平均值没有显著差异。当研究损伤部位以上和以下的弥散张量和弥散张量纤维束示踪成像参数的差异时，发现颈椎 SCI 患者的 FA 和束密度在胸段显著降低。胸段 SCI 患者在颈椎段也观察到了类似的趋势。在比较 TD 组和 SCI 组时，FA 和束密度是检测慢性儿科 SCI 脊髓功能变化的最敏感参数。结果表明，DTI 和 DTT 均有可能成为 SCI 诊断的影像学生物标志物。
