利用电阻抗技术分析胶质瘤生物特性识别肿瘤边界的方法研究

Gliomas comprise the most common type of primary central nervous system tumors. As gliomas grow in an infiltrative pattern, it is often difficult to identify the tumor boundary during operation, which has become a key obstacle affecting the extent of surgical resection, the recurrence rate and preservation of nerve function. The physiological and pathological conditions of gliomas can be drawn from the electrical characteristics of the tissue by electrical bioimpedance measurement technology, a frontier technology that is developing quickly in the biomedical engineering field. Despite the obvious difference in electrical impedance performance between glioma and the brain tissue, no study has been reported to identify the tumor boundary by impedance technology. The present study was attempted to establish a novel method through analysis of electrical properties of biological tissues in a glioma animal model using multiple methods of electrical bioimpedance measurement, including three-dimensional electric field measurement, signal treatment and analysis, and mathematical statistics to reveal distinctive characteristics of electrical properties between glioma, glioma boundary and normal brain tissue, establish their representation types, and use these representation types to determine the tumor boundary in vivo for the sake of providing help for identifying the tumor boundary in tumor resection. The result of the study is expected to provide theoretical and technical support in developing diagnostic instruments that can identify the tumor boundary and determine whether there is any tumor residue during operation.

胶质瘤是最常见脑肿瘤，呈浸润性生长，手术切除过程中难以判断肿瘤边界，术后易复发，如何识别胶质瘤边界是影响手术切除程度、肿瘤复发率和神经功能保留程度的关键。生物电阻抗技术可利用生物组织的电特性及变化规律获取人体生理、病理相关生物信息，是生物医学工程学前沿技术，发展迅速。胶质瘤和脑组织有显著电性能差异，但未见有利用其差异，识别胶质瘤边界的研究。本研究拟建立胶质瘤动物模型，尝试利用多种电阻抗测量方法，通过立体电场测量手段、信号处理分析手段、数理统计手段等生物组织电性能分析技术，测量胶质瘤和脑组织电性能，建立三者的电性能表征式或电性能参数范围，揭示胶质瘤、胶质瘤边界和正常脑组织在电性能方面差异的显著性特征，并利用获得的表征式或电性能范围在体判断所测组织的生物学性质，为胶质瘤切除术中识别胶质瘤边界提供帮助。本研究的完成，将有助于研发术中识别胶质瘤边界的辅助诊断仪器，提高胶质瘤手术质量。

胶质瘤呈浸润性生长,术后易复发,如何识别胶质瘤边界是影响手术切除程度、肿瘤复发率和神经功能保留程度的关键。本课题利用生物电阻抗技术分析胶质瘤和脑组织的电性能差异，协助判断胶质瘤和脑组织,以识别胶质瘤边界。本研究采用多种方案建立了生物电阻抗离体测量平台，经数据稳定性评估后，用于测量胶质瘤和脑组织电性能；并进一步建立了在体电阻抗测量平台，设计了多种测量用探头，进行在体胶质瘤和脑组织的测量和识别。实验结果显示：自行设计的AD5933平台在典型电子元件模型测试实验中，测量误差5%以内，重复测量10次的方差小于0.1，有较高的数据稳定性和可重复性；在采用阻抗分析仪建立的离体生物电阻抗测量平台检测中，分别测试了猪脑、猪肾和猪肝的生物电阻抗，其阻抗值均有明显差异（P<0.001）,其电性能值可用于鉴别三者不同生物组织；在采用四电极法离体区别裸鼠脑组织与胶质瘤实验结果显示：四电极测试法经仿真测试能产生较均匀的电场，该方法测得的裸鼠脑与胶质瘤电性能有明显差异（P<0.001）。进一步用该测量方法测量人脑胶质瘤电性能，并对其进行了等效电路的模拟，该等效电路能较好地模拟离体胶质瘤组织的复阻抗模值和相位角的频率特性；建立了在体测量生物电性能平台，分别设计了四电极，六电极，及环形电极检测探头，对鼠脑胶质瘤和正常鼠脑组织进行了测量，结果显示两者间同样也存在明显差异。该课题获得数据为进一步应用临床在胶质瘤切除术中识别胶质瘤边界提供帮助,并将有助于研发术中识别胶质瘤边界的辅助诊断仪器,提高胶质瘤手术质量。