The corticospinal tract (CST) is a critically important white matter fiber tract in the human brain that enables control of voluntary movements of the body. Diffusion MRI tractography is the only method that enables the study of the anatomy and variability of the CST pathway in human health. In this work, we explored the performance of six widely used tractography methods for reconstructing the CST and its somatotopic organization. We perform experiments using diffusion MRI data from the Human Connectome Project. Four quantitative measurements including reconstruction rate, the WM-GM interface coverage, anatomical distribution of streamlines, and correlation with cortical volumes to assess the advantages and limitations of each method. Overall, we conclude that while current tractography methods have made progress toward the well-known challenge of improving the reconstruction of the lateral projections of the CST, the overall problem of performing a comprehensive CST reconstruction, including clinically important projections in the lateral (hand and face area) and medial portions (leg area), remains an important challenge for diffusion MRI tractography.

翻译：皮质脊髓束是人体大脑中极其重要的白质纤维束，负责控制身体的随意运动。弥散磁共振纤维成像是目前唯一能在人体健康状态下研究皮质脊髓束通路解剖结构及其变异性的方法。本研究系统评估了六种常用纤维追踪方法在重建皮质脊髓束及其躯体组织映射中的表现。我们利用人类连接组项目的弥散磁共振数据开展实验，通过重建率、白质-灰质界面覆盖率、流线解剖分布及与皮层体积相关性等四项定量指标，系统评估各方法的优势与局限。总体而言，尽管当前纤维追踪方法在改善皮质脊髓束外侧投射重建这一公认难题上取得了进展，但实现包含外侧（手部和面部区域）及内侧（腿部区域）具有临床重要投射的完整皮质脊髓束重建，仍是弥散磁共振纤维成像面临的重大挑战。