Establishment of sentinel lymph node detection using impedance CT

阻抗CT前哨淋巴结检测的建立

• 批准号: 15591334
• 负责人: YAMADA Takuya
• 金额: $ 2.43万
• 依托单位: Gifu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15591334/
• 关键词: impedance CT; sentinel lymph node; 誘電特性; Ferumoxides

Electrical evaluation of surgically resected organs was conducted to determine whether electrical differences exist between normal tissue and malignant lesions. Specifically, dielectric properties of normal gastric mucosa and malignant lesions were evaluated, and "tan δm", the maximum tan δ in the β dispersion range, was calculated. No significant differences were observed in "tan δm" between normal gastric mucosa and malignant lesions in patients with well-differentiated adenocarcinoma. However, in patients with poorly differentiated adenocarcinoma, "tan δm" was 3.35 ± 0.21 in normal gastric mucosa, 4.66 ± 0.79 in lesions with tumor depths of m to mp, and 7.60 ± 1.23 in areas with tumor depths of ss to se, indicating statistically significant differences. Histologically, "tan δm" was shown to be higher for markedly poorly differentiated or advanced tumors in terms of structural changes. Meanwhile, electrical detection of lymph node accumulation using iron colloids was attempted by altering colloid diameter, content, dose, administration time, and measurement time, but no electrical differences were observed between normal lymph nodes and lymph nodes containing iron. In addition, the dielectric properties of experimental animal stomachs and large intestines were measured in a multi-frequency range from 1 kHz to 1 MHz using electrodes for contact-type multiple-point measurements and an existing impedance analyzer (HP4194A). However, data reproducibility was poor, and the results were thought to reflect individual differences among animals. Although a conductivity distribution map of dielectric properties was created based on obtained data using equipotential back-projection, lymph nodes could not be visualized on obtained images due to insufficient spatial resolution. Based on the above, although electrical differences may exist between normal and cancer tissues, establishment of sentinel lymph node detection using impedance CT in practice may prove difficult.

对手术切除的器官进行电评价，以确定正常组织和恶性病变之间是否存在电差异。具体来说，我们评估了正常胃黏膜和恶性病变的介电特性，并计算了β色散范围内tan δ的最大值“tan δm”。高分化腺癌患者正常胃黏膜与恶性胃粘膜“tan δm”无明显差异。而在低分化腺癌患者中，正常胃黏膜“tan δm”为3.35±0.21，肿瘤深度m ~ mp区为4.66±0.79，肿瘤深度ss ~ se区为7.60±1.23，差异有统计学意义。组织学上，就结构改变而言，“tan δm”在明显低分化或晚期肿瘤中显示更高。同时，通过改变胶体的直径、含量、剂量、给药时间和测量时间，尝试利用铁胶体对淋巴结积聚进行电检测，但正常淋巴结和含铁淋巴结的电检测结果无差异。此外，采用接触式多点测量电极和现有阻抗分析仪（HP4194A），在1 kHz ~ 1 MHz的多频率范围内测量实验动物胃和大肠的介电特性。然而，数据的可重复性很差，结果被认为反映了动物之间的个体差异。虽然利用等电位反向投影技术获得了电介质性质的电导率分布图，但由于空间分辨率不足，无法在获得的图像上显示淋巴结。综上所述，尽管正常组织和癌组织之间可能存在电性差异，但在实践中使用阻抗CT建立前哨淋巴结检测可能是困难的。