单克隆抗体磁共振对比剂(Gd-DTPA-chTNT)对荷人肝癌裸鼠模型瘤体信号改变规律的初步探讨

目的 通过探讨单克隆抗体磁共振对比剂(Gd—DTPA—chTNT)对裸鼠瘤体信号改变的规律，评价Gd—DTPA—chTNT诊断肝肿瘤的可行性及有效性。材料与方法 首先chTNT与caDTPA(DTPA环二酸酐)连接，再标记上钆离子，制得Gd—DTPA—chTNT；将5～6周龄SPF级BLAB/C裸鼠皮下接种人肝癌瘤块作为动物模型；将裸鼠随机分成实验组与对照组，前者腹腔注射Gd—DTPA—chTNT1ml，后者腹腔注射含相同Gd^3 浓度的Gd—DTPA，观测注射前后T1WI瘤体信号改变情况。注射后扫描时间点选为6h、24h、36h、48h、60h、72h。结果 注射对比剂36h后，实验组裸鼠瘤体信号增加与扫描前差异有统计意义，48h时差异最大，72h时仍有差异。对照组注射对比剂后任何时间点与扫描前瘤体信号差异均无统计意义。结论 Gd—DTPA—chTNT对裸鼠瘤体信号增加的持续性提高了肝肿瘤定性诊断特异性。

MR Signal Variations of Transplanted Human Hepatoma in Nude Mice following Use of Monoclonal Antibody MR Contrast Agent

Objective To observe MR signal variations of transplanted human hepatoma in nude mice after the use of monoclonal antibody MR contrast agent (Gd-DTPA-chTNT), to evaluate the feasibility and effectiveness of this technique.Materials and Methods After chTNT monoclonal antibody was conjugated with caDTPA, GdCl3 was added to label DTPA-chTNT, and Gd-DTPA-chTNT, an MR contrast agent, was thus prepared. Nude mice with transplanted human hepatoma were used as experimental model. The mice were divided into study group and control group. One ml Gd-DTPA-chTNT was injected into the abdominal cavity of the mice in the study group, while the mice in the control group received Gd-DTPA (containing the same amount of gadolinium). The signal features of the tumor before and after the injection were observed on T 1WI. MR scanning was carried out at 6, 24, 36, 48, 60 and 72 hours after the injection. Results Thirty-six hours after the injection, the tumor signal intensity in the study group was significantly higher than that observed before the injection. The biggest difference appeared at 48 hours and the difference was remained at 72 hours. In the control group, the signal intensity of the tumor at any time-point after the injection showed no statistically difference with that observed before the injection.Conclusion Gd-DTPA-chTNT can produce a sustainable increase in the signal intensity of the transplanted human hepatoma in nude mice, thus, improve the diagnosis of the hepatic tumors.