甲状腺瘤是女性内分泌系统的恶性疾病，其早期诊断，肿瘤边界的判定，治疗效果的评估一直是亟需解决的问题。单模态成像技术用于肿瘤诊断各有优缺点，如CT分辨率高但灵敏度低，SPECT则恰恰相反，发展基于两者的双模态成像造影剂为以上问题的解决提供了可能。本项目拟设计基于碘-125标记的金银复合纳米造影剂用于甲状腺肿瘤的SPECT-CT双模态成像研究以期得到可用于准确诊断早期甲状腺瘤、高分辨判定肿瘤边界、高灵敏评估愈后效果的双模态影像技术手段。具体研究内容：1）设计合成尺寸均一、生物相容性好的碘-125放射性同位素标记金银复合纳米粒子；2）探究表面标记碘-125放射性同位素的金银复合纳米材料在甲状腺瘤部位的SPECT-CT显影效果；3）系统探讨碘-125标记金银复合纳米粒子对靶向肿瘤细胞成像效果的灵敏性、特异性和准确性，并对双模态成像造影剂在动物体内的成像效果和安全性进行评价。

Thyroid adenoma is a common female malignant disease of endocrine system. The early diagnosis, tumor border and the evaluation of treatment effect have been in urgent need. Each single-mode imaging has its advantages and disadvantages, such as X-ray Computed Tomography (CT) has high resolution but low sensitivity, on the contrary, Single Photon Emission Imaging (SPECT) has high sensitivity but low resolution. Development based on SPECT-CT bimodal imaging contrast agents is in necessary to solve the above problems. This project is synthesis of Iodine-125 tagged Au@Ag nanocomposites as contrast agents for thyroid tumor SPECT-CT dual mode imaging. Research Contents: 1) Controllable preparation of uniform size and good biocompatibility Au@Ag nanocomposites; 2) Marked Iodine-125 on the surface to build bimodal thyroid tumor SPECT-CT imaging probe and to explore its tumor cell targeting specificity; 3) Research on the structure and the imaging effect (sensitivity, specificity and accuracy) of iodine-125 tagged Au@Ag nanocomposites, and discuss on the imaging effect in vivo and the evaluation on the safety of the nanoprobe. Research is expected for early diagnosis of thyroid tumor accurately, high resolution determine tumor boundary, high sensitive assessment of after curing effect because of the newly bimodal contrast agents.