Spinal cord injury (SCI) is a devastating incidence leading to permanent paralysis and loss of sensory-motor functions potentially resulting in the formation of lesions within the spinal cord. Imaging biomarkers obtained from magnetic resonance imaging (MRI) scans can predict the functional recovery of individuals with SCI and help choose the optimal treatment strategy. Currently, most studies employ manual quantification of these MRI-derived biomarkers, which is a subjective and tedious task. In this work, we propose (i) a universal tool for the automatic segmentation of intramedullary SCI lesions, dubbed \texttt{SCIsegV2}, and (ii) a method to automatically compute the width of the tissue bridges from the segmented lesion. Tissue bridges represent the spared spinal tissue adjacent to the lesion, which is associated with functional recovery in SCI patients. The tool was trained and validated on a heterogeneous dataset from 7 sites comprising patients from different SCI phases (acute, sub-acute, and chronic) and etiologies (traumatic SCI, ischemic SCI, and degenerative cervical myelopathy). Tissue bridges quantified automatically did not significantly differ from those computed manually, suggesting that the proposed automatic tool can be used to derive relevant MRI biomarkers. \texttt{SCIsegV2} and the automatic tissue bridges computation are open-source and available in Spinal Cord Toolbox (v6.4 and above) via the \texttt{sct\_deepseg -task seg\_sc\_lesion\_t2w\_sci} and \texttt{sct\_analyze\_lesion} functions, respectively.

翻译：脊髓损伤（SCI）是一种破坏性事件，可导致永久性瘫痪和感觉运动功能丧失，并可能在脊髓内形成病灶。从磁共振成像（MRI）扫描中获得的影像学生物标志物可以预测SCI患者的功能恢复情况，并有助于选择最佳治疗策略。目前，大多数研究采用人工量化这些MRI衍生的生物标志物，这是一项主观且繁琐的任务。在本工作中，我们提出了（i）一种用于自动分割髓内SCI病灶的通用工具，命名为 \texttt{SCIsegV2}，以及（ii）一种从分割病灶中自动计算组织桥宽度的方法。组织桥代表病灶旁保留的脊髓组织，与SCI患者的功能恢复相关。该工具在一个来自7个中心的异质性数据集上进行了训练和验证，该数据集包含不同SCI阶段（急性、亚急性和慢性）和病因（创伤性SCI、缺血性SCI和退行性颈椎病）的患者。自动量化的组织桥与手动计算的结果无显著差异，表明所提出的自动工具可用于推导相关的MRI生物标志物。\texttt{SCIsegV2} 和自动组织桥计算功能是开源的，可通过脊髓工具箱（v6.4及以上版本）中的 \texttt{sct\_deepseg -task seg\_sc\_lesion\_t2w\_sci} 和 \texttt{sct\_analyze\_lesion} 函数分别获取。