DIELECTRIC-PROPERTIES OF HUMAN GLIOMA AND SURROUNDING TISSUE
DIELECTRIC-PROPERTIES OF HUMAN GLIOMA AND SURROUNDING TISSUE
复制标题
DOI：
10.3109/02656739209005023
复制
发表时间：
1992-11-01
影响因子：
3.1
通讯作者：
YU, J
中科院分区：
文献类型：
--
作者：
LU, Y;LI, B;YU, J
测量了5例人脑胶质瘤及其周围组织的介电特性。使用网络分析仪和同轴线电容传感器在5-500 MHz的频率和24 +/- 0.5 ℃下进行实验。肿瘤的介电常数和电导率比周围组织的介电常数和电导率高30%，这是由于它们的含水量较高。肿瘤的低分化特征明显地反映在介电特性上。即肿瘤介电弛豫的弛豫时间分布的较小参数。与介电数据，肿瘤周围组织的功率吸收比计算为四个代表性的电磁（EM）照射情况。计算结果表明，功率吸收比强烈依赖于电磁波的入射方向和最佳频率。为了提高治疗效率，在100 MHz左右的最佳频率下使电场矢量（E）平行于肿瘤/周围组织的界面是合适的，并且在用于脑肿瘤的EM热疗的应用中必须避免E垂直于界面的情况。
Dielectric properties of human glioma and surrounding tissue from five patients were measured. Experiments were performed at frequencies of 5-500 MHz at 24 +/- 0.5-degrees-C using a Network Analyser and a coaxial line capacitive sensor. The permittivity and conductivity of tumours were 30% higher than that of the surrounding tissues due to their higher water content. The characteristic of less differentiation in tumours clearly was reflected in the dielectric properties. namely a smaller parameter for the relaxation time distribution of the tumour's dielectric relaxation. With the dielectric data, the power absorption ratios of tumour to surrounding tissue were calculated for four representative electromagnetic (EM) irradiation cases. The calculation shows that power absorption ratios are strongly dependent on the incident direction of the EM wave and optimum frequency. To improve therapeutic efficiency, it is appropriate to have the electric field vector (E) parallel to the interface of tumour/surrounding tissue at optimum frequencies around 100 MHz, and the case of E perpendicular to the interface must be avoided in applications of EM hyperthermia for brain tumours.