Dauleac Corentin, Boukhari Amine, Jacquesson Timothée, Frindel Carole, Cotton François
Hôpital neurologique et neurochirurgical Pierre Wertheimer, Service de Neurochirurgie, Hospices Civils de Lyon, 59, Bd Pinel, 69003, Lyon, France.
Université Lyon I, Université Claude Bernard, Lyon, France.
Clin Neuroradiol. 2025 Jun;35(2):315-324. doi: 10.1007/s00062-024-01481-5. Epub 2024 Dec 20.
This study aimed to characterize spinal cord microstructure in healthy subjects using high angular resolution diffusion imaging (HARDI) and tractography.
Forty-nine healthy subjects (18-50 years, divided into 2 age groups) were included in a prospective study. HARDI of the cervical spinal cord were acquired using a 3T MRI scanner with: 64 directions, b‑value: 1000s/mm, reduced field-of-view (zonally magnified oblique multi-slice), and opposed phase-encoding directions. Distortions were corrected using the FSL software package. Fiber tracking was performed using a deterministic approach with DSI-Studio software. Tensor metrics-fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD)-and tractography statistics were then extracted, at each spine level, and after grey-white matter segmentation.
The microstructural organization of the spinal cord differed between upper and lower cervical spine levels: FA, and AD significantly decreased (p < 0.001); and RD significantly increased (p < 0.05) in lower levels, demonstrating changes in axonal density and myelinated fibers according to a cranio-caudal axis. FA, MD, AD, and RD values were significantly higher in spinal cord white matter (p < 0.0001), compared to grey matter. Age was not associated with a significant change in FA, while there is for MD, AD and RD (p < 0.05). Spinal cord tractography may provide information on the architectural organization of fibers and spinal tracts.
This study proposes a database in cervical spinal cord HARDI, allowing to study the microstructural organization of the spinal cord in healthy subjects, and providing a foundation for comparison with patients presenting spinal cord pathologies.
本研究旨在利用高角分辨率扩散成像（HARDI）和纤维束成像对健康受试者的脊髓微观结构进行特征描述。
49名健康受试者（年龄在18至50岁之间，分为2个年龄组）纳入一项前瞻性研究。使用3T磁共振成像扫描仪采集颈段脊髓的HARDI数据，扫描参数如下：64个方向，b值：1000s/mm²，缩小视野（区域放大斜向多层），以及相反的相位编码方向。使用FSL软件包校正畸变。使用DSI-Studio软件采用确定性方法进行纤维追踪。然后在每个脊柱节段以及灰质-白质分割后提取张量指标——分数各向异性（FA）、平均扩散率（MD）、轴向扩散率（AD）、径向扩散率（RD）——以及纤维束成像统计数据。
颈段脊髓的微观结构组织在颈椎上段和下段之间存在差异：下段的FA和AD显著降低（p<0.001）；RD显著升高（p<0.05），表明轴突密度和有髓纤维沿头尾轴发生了变化。与灰质相比，脊髓白质中的FA、MD、AD和RD值显著更高（p<0.0001）。年龄与FA的显著变化无关，而与MD、AD和RD有关（p<0.05）。脊髓纤维束成像可提供有关纤维和脊髓束结构组织的信息。
本研究建立了一个颈段脊髓HARDI数据库，有助于研究健康受试者脊髓的微观结构组织，并为与脊髓疾病患者进行比较提供基础。
