Department of Neurosurgery, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
German Cancer Research Center, Division of Medical Image Computing, Heidelberg, Germany.
Acta Neurochir (Wien). 2023 Apr;165(4):1041-1051. doi: 10.1007/s00701-023-05540-7. Epub 2023 Mar 2.
Fiber tracking (FT) is used in neurosurgical planning for the resection of lesions in proximity to fiber pathways, as it contributes to a substantial amelioration of postoperative neurological impairments. Currently, diffusion-tensor imaging (DTI)-based FT is the most frequently used technique; however, sophisticated techniques such as Q-ball (QBI) for high-resolution FT (HRFT) have suggested favorable results. Little is known about the reproducibility of both techniques in the clinical setting. Therefore, this study aimed to examine the intra- and interrater agreement for the depiction of white matter pathways such as the corticospinal tract (CST) and the optic radiation (OR).
Nineteen patients with eloquent lesions in the proximity of the OR or CST were prospectively enrolled. Two different raters independently reconstructed the fiber bundles by applying probabilistic DTI- and QBI-FT. Interrater agreement was evaluated from the comparison between results obtained by the two raters on the same data set acquired in two independent iterations at different timepoints using the Dice Similarity Coefficient (DSC) and the Jaccard Coefficient (JC). Likewise, intrarater agreement was determined for each rater comparing individual results.
DSC values showed substantial intrarater agreement based on DTI-FT (rater 1: mean 0.77 (0.68-0.85); rater 2: mean 0.75 (0.64-0.81); p = 0.673); while an excellent agreement was observed after the deployment of QBI-based FT (rater 1: mean 0.86 (0.78-0.98); rater 2: mean 0.80 (0.72-0.91); p = 0.693). In contrast, fair agreement was observed between both measures for the repeatability of the OR of each rater based on DTI-FT (rater 1: mean 0.36 (0.26-0.77); rater 2: mean 0.40 (0.27-0.79), p = 0.546). A substantial agreement between the measures was noted by applying QBI-FT (rater 1: mean 0.67 (0.44-0.78); rater 2: mean 0.62 (0.32-0.70), 0.665). The interrater agreement was moderate for the reproducibility of the CST and OR for both DSC and JC based on DTI-FT (DSC and JC ≥ 0.40); while a substantial interrater agreement was noted for DSC after applying QBI-based FT for the delineation of both fiber tracts (DSC > 0.6).
Our findings suggest that QBI-based FT might be a more robust tool for the visualization of the OR and CST adjacent to intracerebral lesions compared with the common standard DTI-FT. For neurosurgical planning during the daily workflow, QBI appears to be feasible and less operator-dependent.
纤维追踪（FT）用于接近纤维通路的病变切除的神经外科规划，因为它有助于显著改善术后神经损伤。目前，基于弥散张量成像（DTI）的 FT 是最常用的技术；然而，诸如用于高分辨率 FT（HRFT）的 Q-ball（QBI）等复杂技术已显示出有利的结果。关于这两种技术在临床环境中的可重复性知之甚少。因此，本研究旨在检查皮质脊髓束（CST）和视辐射（OR）等白质通路描绘的内部和内部评估者之间的一致性。
前瞻性纳入 19 例位于 OR 或 CST 附近的有表达病变的患者。两名不同的评估者分别通过应用概率 DTI 和 QBI-FT 重建纤维束。通过比较同一数据集在不同时间点的两个独立迭代中由两名评估者获得的结果，使用 Dice 相似系数（DSC）和 Jaccard 系数（JC）评估评估者之间的一致性。同样，通过比较每个评估者的单个结果来确定每个评估者的内部评估者之间的一致性。
基于 DTI-FT 的 DSC 值显示出较大的内部评估者之间的一致性（评估者 1：平均值为 0.77（0.68-0.85）；评估者 2：平均值为 0.75（0.64-0.81）；p=0.673）；而在应用基于 QBI 的 FT 后观察到极好的一致性（评估者 1：平均值为 0.86（0.78-0.98）；评估者 2：平均值为 0.80（0.72-0.91）；p=0.693）。相反，在应用基于 DTI-FT 的每个评估者的 OR 可重复性方面，两种方法之间的一致性为公平（评估者 1：平均值为 0.36（0.26-0.77）；评估者 2：平均值为 0.40（0.27-0.79），p=0.546）。应用 QBI-FT 时，两种方法之间的一致性为实质性（评估者 1：平均值为 0.67（0.44-0.78）；评估者 2：平均值为 0.62（0.32-0.70），0.665）。基于 DTI-FT 的 DSC 和 JC 对 CST 和 OR 的可重复性的评估者之间的一致性为中度（DSC 和 JC≥0.40）；而在应用基于 QBI 的 FT 后，两种纤维束的 DSC 显示出较大的评估者之间的一致性（DSC>0.6）。
我们的研究结果表明，与常用的标准 DTI-FT 相比，基于 QBI 的 FT 可能是一种更强大的工具，用于可视化颅内病变附近的 OR 和 CST。对于日常工作流程中的神经外科计划，QBI 似乎是可行的，并且对操作人员的依赖性较小。
