Mandelli Maria Luisa, Berger Mitchel S, Bucci Monica, Berman Jeffrey I, Amirbekian Bagrat, Henry Roland G
Departments of Neurology.
J Neurosurg. 2014 Aug;121(2):349-58. doi: 10.3171/2014.4.JNS131160. Epub 2014 Jun 6.
The aim of this paper was to validate the diffusion tensor imaging (DTI) model for delineation of the corticospinal tract using cortical and subcortical white matter electrical stimulation for the location of functional motor pathways.
The authors compare probabilistic versus deterministic DTI fiber tracking by reconstructing the pyramidal fiber tracts on preoperatively acquired DTI in patients with brain tumors. They determined the accuracy and precision of these 2 methods using subcortical stimulation points and the sensitivity using cortical stimulation points. The authors further explored the reliability of these methods by estimation of the potential that the found connections were due to a random chance using a novel neighborhood permutation method.
The probabilistic tracking method delineated tracts that were significantly closer to the stimulation points and was more sensitive than deterministic DTI fiber tracking to define the tracts directed to the motor sites. However, both techniques demonstrated poor sensitivity to finding lateral motor regions.
This study highlights the importance of the validation and quantification of preoperative fiber tracking with the aid of electrophysiological data during the surgery. The poor sensitivity of DTI to delineate lateral motor pathways reported herein suggests that DTI fiber tracking must be used with caution and only as adjunctive data to established methods for motor mapping.
本文旨在验证扩散张量成像（DTI）模型，该模型通过皮质和皮质下白质电刺激来定位功能性运动通路，以描绘皮质脊髓束。
作者通过在脑肿瘤患者术前获取的DTI上重建锥体纤维束，比较概率性与确定性DTI纤维追踪。他们使用皮质下刺激点确定这两种方法的准确性和精确性，并使用皮质刺激点确定敏感性。作者进一步通过一种新颖的邻域置换方法估计所发现的连接是由于随机机会的可能性，来探索这些方法的可靠性。
概率性追踪方法描绘的束与刺激点明显更接近，并且在定义指向运动部位的束方面比确定性DTI纤维追踪更敏感。然而，两种技术在发现外侧运动区域方面均表现出较差的敏感性。
本研究强调了在手术期间借助电生理数据对术前纤维追踪进行验证和量化的重要性。本文报道的DTI描绘外侧运动通路的敏感性较差，表明DTI纤维追踪必须谨慎使用，并且仅作为运动图谱既定方法的辅助数据。
