Background

There is a lack of information regarding electrical properties of white matter and brain tumors.

Objective

To investigate the feasibility of in-vivo measurement of electrical resistivity during brain surgery and establish a better understanding of the resistivity patterns of brain tumors in correlation to the white matter.

Methods

A bipolar probe was used to measure electrical resistivity during surgery in a prospective cohort of patients with brain tumors. For impedance measurement, the probe applied a constant current of 0.7 μA with a frequency of 140 Hz. The measurement was performed in the white matter within and outside peritumoral edema as well as in non-enhancing, enhancing and necrotic tumor areas. Resistivity values expressed in ohmmeter (Ω∗m) were compared between different intracranial tissues and brain tumors.

Results

Ninety-two patients (gliomas WHO II:16, WHO III:10, WHO IV:33, metastasis:33) were included. White matter outside peritumoral edema had higher resistivity values (13.3 ± 1.7 Ω∗m) than within peritumoral edema (8.5 ± 1.6 Ω∗m), and both had higher values than brain tumors including non-enhancing (WHO II:6.4 ± 1.3 Ω∗m, WHO III:6.3 ± 0.9 Ω∗m), enhancing (WHO IV:5 ± 1 Ω∗m, metastasis:5.4 ± 1.3 Ω∗m) and necrotic tumor areas (WHO IV:3.9 ± 1.1 Ω∗m, metastasis:4.3 ± 1.3 Ω∗m), p=<0.001. No difference was found between low-grade and anaplastic gliomas, p = 0.808, while resistivity values in both were higher than the highest values found in glioblastomas, p = 0.003 and p = 0.004, respectively.

Conclusions

The technique we applied enabled us to measure electrical resistivity of white matter and brain tumors in-vivo presumably with a significant effect with regard to dielectric polarization. Our results suggest that there are significant differences within different areas and subtypes of brain tumors and that white matter exhibits higher electrical resistivity than brain tumors.

中文翻译：

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深入了解白质和脑肿瘤的电阻率

背景

缺乏关于白质和脑肿瘤的电特性的信息。

客观的

研究在脑手术期间体内测量电阻率的可行性，并更好地了解与白质相关的脑肿瘤电阻率模式。

方法

双极探头用于在脑肿瘤患者的前瞻性队列中测量手术期间的电阻率。对于阻抗测量，探头以 140 Hz 的频率施加 0.7 μA 的恒定电流。测量是在肿瘤周围水肿内外的白质以及非增强、增强和坏死的肿瘤区域中进行的。比较不同颅内组织和脑肿瘤之间以欧姆表（Ω*m）表示的电阻率值。

结果

纳入了 92 名患者（胶质瘤 WHO II：16，WHO III：10，WHO IV：33，转移瘤：33）。瘤周水肿外的白质电阻率值（13.3 ± 1.7 Ω*m）高于瘤周水肿内的电阻率值（8.5 ± 1.6 Ω*m），并且两者都比包括非增强在内的脑肿瘤的电阻率值（WHO II：6.4 ± 1.3 Ω）更高∗m，WHO III：6.3 ± 0.9 Ω∗m），增强（WHO IV：5 ± 1 Ω∗m，转移：5.4 ± 1.3 Ω∗m）和坏死肿瘤区域（WHO IV：3.9 ± 1.1 Ω∗m，转移：4.3 ± 1.3 Ω*m)，p=<0.001。在低级别胶质瘤和间变性胶质瘤之间没有发现差异，p = 0.808，而两者的电阻率值均高于胶质母细胞瘤中的最高值，分别为 p = 0.003 和 p = 0.004。

结论

我们应用的技术使我们能够测量体内白质和脑肿瘤的电阻率，这可能对介电极化有显着影响。我们的研究结果表明，脑肿瘤的不同区域和亚型存在显着差异，并且白质表现出比脑肿瘤更高的电阻率。