Institute of Biomaterial and Biomedical Engineering, University of Toronto, Toronto, Canada.
J Neural Eng. 2018 Aug;15(4):046034. doi: 10.1088/1741-2552/aacb96. Epub 2018 Jun 11.
Accurate neuronavigation is essential for optimal outcomes in therapeutic brain stimulation. MRI-guided neuronavigation, the current gold standard, requires access to MRI and frameless stereotaxic equipment, which is not available in all settings. Scalp-based heuristics depend on operator skill, with variable reproducibility across operators and sessions. An intermediate solution would offer superior reproducibility and ease-of-use to scalp measurements, without requiring MRI and frameless stereotaxy.
We present and assess a novel neuronavigation method using commercially-available, inexpensive 3D head scanning, computer-aided design, and 3D-printing tools to fabricate form-fitted headsets for individuals that hold a stimulator, such as an rTMS coil, in the desired position over the scalp.
20 individuals underwent scanning for fabrication of individualized headsets designed for rTMS of the left dorsolateral prefrontal cortex (DLPFC). An experienced operator then performed three trials per participant of three neuronavigation methods: MRI-guided, scalp-measurement (BeamF3 method), and headset placement, and marked the sites obtained. Accuracy (versus MRI-guidance) and reproducibility were measured for each trial of each method.
Within-subject accuracy (against a gold-standard centroid of three MRI-guided localizations) for MRI-guided, scalp-measurement, and headset methods was 3.7 ± 1.6 mm, 14.8 ± 7.1 mm, and 9.7 ± 5.2 mm respectively, with headsets significantly more accurate (M = 5.1, p = 0.008) than scalp-measurement methods. Within-subject reproducibility (against the centroid of 3 localizations in the same modality) was 3.7 ± 1.6 mm (MRI), 4.2 ± 1.4 (scalp-measurement), and 1.4 ± 0.7 mm (headset), with headsets achieving significantly better reproducibility than either other method (p < 0.0001).
3D-printed headsets may offer good accuracy, superior reproducibility and greater ease-of-use for stimulator placement over DLPFC, in settings where MRI-guidance is impractical.
准确的神经导航对于治疗性脑刺激的最佳效果至关重要。目前的金标准是 MRI 引导的神经导航，但它需要 MRI 和无框架立体定向设备，而这些设备并非在所有环境中都能获得。基于头皮的启发式方法依赖于操作人员的技能，不同操作人员和不同会话之间的可重复性也存在差异。一种中间解决方案是提供优于头皮测量的可重复性和易用性，而无需 MRI 和无框架立体定向。
我们提出并评估了一种使用商业上可用的、廉价的 3D 头部扫描、计算机辅助设计和 3D 打印工具的新型神经导航方法，用于为个体制造贴合的头盔，这些个体将刺激器（例如 rTMS 线圈）放置在头皮上期望的位置。
20 名个体接受了用于制造个性化头盔的扫描，这些头盔设计用于左背外侧前额叶皮层（DLPFC）的 rTMS。然后，一名经验丰富的操作人员对每个参与者进行了三次试验，分别使用三种神经导航方法：MRI 引导、头皮测量（BeamF3 方法）和头盔放置，并标记获得的位置。测量了每种方法的每次试验的准确性（相对于 MRI 引导）和可重复性。
MRI 引导、头皮测量和头盔方法的个体内准确性（与三个 MRI 引导定位的金标准中心体相比）分别为 3.7 ± 1.6mm、14.8 ± 7.1mm 和 9.7 ± 5.2mm，头盔方法明显更准确（M = 5.1，p = 0.008）比头皮测量方法。个体内可重复性（与同一模态的三个定位的中心体相比）分别为 3.7 ± 1.6mm（MRI）、4.2 ± 1.4mm（头皮测量）和 1.4 ± 0.7mm（头盔），头盔方法的可重复性明显优于其他两种方法（p < 0.0001）。
在 MRI 引导不切实际的情况下，3D 打印头盔可能为 DLPFC 刺激器的放置提供良好的准确性、更高的可重复性和更高的易用性。
