Objective: To investigate the differences in dielectric properties (relative permittivity and conductivity) between the mucosal surface and serosal surface of malignant colorectal tissues, adjacent tissues at 1 cm and 3 cm from the tumor focus and normal colorectal tissues.
Methods: The dielectric properties of the mucosal and serosal surface of malignant colorectal tissues, adjacent tissues (1 cm and 3 cm) and normal colorectal tissues from 39 patients with colorectal cancer were measured with an open-ended coaxial probe within the frequency range of 50 MHz-3 GHz, and the corresponding dielectric properties were analyzed respectively; statistical tests of the data were used to analyze the dielectric properties at 6 specific frequency points.
Results: The dielectric properties were significantly higher in the malignant mucosa surface than in the adjacent tissues and normal colorectal tissues at the 6 specific frequency points (P<0.01). The dielectric properties decreased progressively in adjacent tissues at 1 cm and 3 cm and normal mucosa surface. The mucosal and serosal surface of malignant tissues showed significant differences in dielectric properties at 64 MHz, 128 MHz, 298 MHz, 433 MHz, and 915 MHz (P<0.01) but not at 2450 MHz (P>0.01), but such differences were not observed in normal tissues (P>0.01).
Conclusion: The dielectric properties of the mucosal surface of the mucosal decrease in the order of malignant colorectal tissue, adjacent tissues at 1 cm and 3 cm from the tumor foci and normal colorectal tissues. The dielectric properties are higher in the mucosal surface than in the serosal surface in the malignant tissue, but comparable in normal colorectal tissues.
目的: 研究结直肠的恶性组织黏膜面与浆膜面、癌旁1、3 cm以及正常组织黏膜面与浆膜面之间的介电特性（相对介电常数和电导率）差异。
方法: 采用开端同轴探头法在50 MHz~3 GHz频段上对39例结直肠癌患者的新鲜离体标本的恶性组织黏膜面与浆膜面、癌旁1、3 cm以及正常组织黏膜面与浆膜面的介电特性分别进行测量，然后分别分析其对应的介电特性，并对其中6个特定频率点的介电特性数据进行统计学检验。
结果: 结果显示恶性组织黏膜面介电特性高于癌旁1、3 cm及正常组织黏膜面的介电特性，并且在六个特定频率点处存在显著性差异（P＜0.01）；癌旁1、3 cm及正常组织黏膜面介电特性依次减小；此外恶性组织黏膜面与黏膜面介电特性在64、128、298、433、915 Mhz存在差异（P＜0.01），而在2450 MHz无差异（P＞0.01）；正常组织黏膜面与浆膜面介电特性不存在显著性差异（P＞0.01）。
结论: 恶性组织，癌旁1、3 cm及正常组织的黏膜面介电特性依次减小。另外，恶性组织黏膜面介电特性高于浆膜面，而正常组织黏膜面与浆膜面的介电特性无显著差异。