1Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden.
2ABX-CRO Advanced Pharmaceutical Services Forschungsgesellschaft mbH, Dresden.
Neurosurg Focus. 2020 Feb 1;48(2):E3. doi: 10.3171/2019.11.FOCUS19759.
Intraoperative optical imaging (IOI) is a marker-free, contactless, and noninvasive imaging technique that is able to visualize metabolic changes of the brain surface following neuronal activation. Although it has been used in the past mainly for the identification of functional brain areas under general anesthesia, the authors investigated the potential of the method during awake surgery. Measurements were performed in 10 patients who underwent resection of lesions within or adjacent to cortical language or motor sites. IOI was applied in 3 different scenarios: identification of motor areas by using finger-tapping tasks, identification of language areas by using speech tasks (overt and silent speech), and a novel approach-the application of IOI as a feedback tool during direct electrical stimulation (DES) mapping of language. The functional maps, which were calculated from the IOI data (activity maps), were qualitatively compared with the functional MRI (fMRI) and the electrophysiological testing results during the surgical procedure to assess their potential benefit for surgical decision-making.The results reveal that the intraoperative identification of motor sites with IOI in good agreement with the preoperatively acquired fMRI and the intraoperative electrophysiological measurements is possible. Because IOI provides spatially highly resolved maps with minimal additional hardware effort, the application of the technique for motor site identification seems to be beneficial in awake procedures. The identification of language processing sites with IOI was also possible, but in the majority of cases significant differences between fMRI, IOI, and DES were visible, and therefore according to the authors' findings the IOI results are too unspecific to be useful for intraoperative decision-making with respect to exact language localization. For this purpose, DES mapping will remain the method of choice.Nevertheless, the IOI technique can provide additional value during the language mapping procedure with DES. Using a simple difference imaging approach, the authors were able to visualize and calculate the spatial extent of activation for each stimulation. This might enable surgeons in the future to optimize the mapping process. Additionally, differences between tumor and nontumor stimulation sites were observed with respect to the spatial extent of the changes in cortical optical properties. These findings provide further evidence that the method allows the assessment of the functional state of neurovascular coupling and is therefore suited for the delineation of pathologically altered tissue.
术中光学成像（IOI）是一种无标记、非接触和非侵入性的成像技术，能够可视化神经元激活后大脑表面代谢变化。尽管过去它主要用于在全身麻醉下识别功能脑区，但作者研究了该方法在清醒手术中的潜力。该方法在 10 名接受皮质语言或运动区附近或内部病变切除术的患者中进行了测量。IOI 在 3 种不同情况下应用：使用手指敲击任务识别运动区，使用言语任务（显性和静默言语）识别语言区，以及一种新方法——在语言的直接电刺激（DES）映射中应用 IOI 作为反馈工具。从 IOI 数据（活性图）计算得出的功能图与术中获得的 fMRI 和电生理测试结果进行定性比较，以评估其对手术决策的潜在益处。结果表明，术中使用 IOI 与术前获得的 fMRI 和术中电生理测量结果一致地识别运动区是可能的。由于 IOI 提供了具有最小附加硬件工作量的空间分辨率高的地图，因此该技术在清醒手术中识别运动区似乎是有益的。使用 IOI 识别语言处理区也是可能的，但在大多数情况下，fMRI、IOI 和 DES 之间存在显著差异，因此根据作者的发现，IOI 结果过于不具体，无法用于术中精确语言定位的决策。为此，DES 映射将仍然是首选方法。然而，IOI 技术在使用 DES 进行语言映射过程中可以提供额外的价值。使用简单的差分成像方法，作者能够可视化和计算每次刺激的激活空间范围。这可能使外科医生在未来能够优化映射过程。此外，还观察到肿瘤和非肿瘤刺激部位之间在皮质光学性质变化的空间范围上存在差异。这些发现进一步证明该方法允许评估神经血管耦联的功能状态，因此适合用于描绘病理性改变的组织。
