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CT是目前临床上应用最广泛的影像学检查方法,具有时间分辨率高、密度分辨率高的特点,CT对比剂以提高病变组织与周围组织的X射线衰减系数差别而应用于临床。目前临床应用最广泛的碘对比剂为小分子对比剂,但其很快就会通过肾脏排泄,血池时间短,使得CT检查技术作为分子影像学工具一直难有较大发展。近年来随着纳米医学的发展,各种高原子序数纳米材料尤其是金纳米材料的合成与开发为CT分子影像提供了新的契机,金纳米棒表面修饰后无毒性、生物相容性好、体内循环时间长,且其表面易于修饰不同的基团,可进行靶向成像,使其成为性能优异的分子影像学载体[1-2]。本研究意在探讨聚乙二醇(polyethylene glycol,PEG)修饰后的金纳米棒制成的新型CT对比剂进行体外CT成像,并对新型对化剂的CT成像参数进行优化及图像质量控制。
金纳米棒作为新型CT对比剂的体外CT成像探索
In vitro CT imaging of gold nanorods as novel CT contrast agents
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摘要:
目的 探讨金纳米棒作为新型CT对比剂的体外CT成像参数。 方法 采用金种子和生长液的方法制备金纳米棒。将聚乙二醇修饰的金纳米棒及非离子型碘对比剂(优维显370)分别制成8种浓度梯度(0、0.1、0.2、0.4、0.6、0.8、1.0、2.0 mg/mL)的溶液。将不同浓度的金纳米棒溶液在空气中及水浴中、不同管电压(80~140 kV)、不同毫安秒(50~400 mAs)等条件下进行体外CT扫描成像,观察其显影效果并测量不同浓度金纳米棒与碘对比剂的CT值。 结果 ① 不同浓度的金纳米棒溶液,水中扫描的CT值最接近真实值,而空气中CT值偏低;②管电压越低,金纳米棒溶液的CT值越高,当溶液浓度为2.0 mg/mL时,不同管电压下的信噪比差异均较明显;③图像质量与毫安秒呈正相关,但当毫安秒≥300 mAs时,图像质量不再有显著变化。④当扫描参数为80 kV、300 mAs时,随着浓度的增加,金纳米棒与碘对比剂的CT值也升高,并呈高度正相关关系(r=0.990、0.994,均P < 0.05),但二者的CT值差异越来越大,金纳米棒较碘对比剂有更高的对比度。 结论 金纳米棒具有比现有CT对比剂更优的显影特征,体外CT在80 kV、300 mAs以及水浴扫描条件下有助于获得优良的显影图像。 -
关键词:
- 纳米粒子 /
- 体层摄影术, X线计算机 /
- 造影剂
Abstract:Objective To investigate the in vitro CT imaging parameters of gold nanorods as novel CT contrast agents. Methods Gold nanorods were prepared with a gold seed and a growth solution. PEG-modified gold nanorods and non-ionic iodine contrast agent were configured into eight concentrations (0, 0.1, 0.2, 0.4, 0.6, 0.8, 1.0, 2.0 mg/mL). The different concentrations of the gold nanorod solutions in air and water bath were subjected to in vitro CT scanning imaging at different tube voltages (80-140 kV) and milliamp seconds (50-400 mAs). The development effect was observed, and the CT value was measured. Results (1) At different concentrations of the gold nanorod solutions, the CT value scanned in water is the closest to the true value, whereas the CT value in air is low. (2) The lower the tube voltage is, the higher the CT value of the gold nanorod solution is. At a solution concentration of 2.0 mg/mL, the difference in the signal-to-noise ratio at different tube voltages is evident. (3) The image quality is positively correlated with mAs, but the image quality is not significantly changed at ≥ 300 mAs. (3) At 80 kV and 300 mAs, the CT values of the gold nanorods and the iodine contrast agent increase as the concentration increases and show a highly positive correlation (r=0.990, 0.994, both P < 0.05). The difference in CT values between the two agents increases, and the contrast of the gold nanorods is higher than that of the iodine contrast agents. Conclusion Gold nanorods exhibit superior imaging characteristics to those of existing CT contrast agents. When gold nanorods are scanned with iCT at 80 kV and 300 mAs and under water bath conditions, an excellent image quality can be achieved. -
Key words:
- Nanoparticles /
- Tomography, X-ray computed /
- Contrast media
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[1] 郭妍妍, 刘雅娟, 王琳, 等.功能化高分子脂质体包裹的纳米金颗粒作为新型CT造影剂的初步研究[J].中国生化药物杂志, 2017, 37 (4):5-8. DOI:10.3969/j.issn.1005-1678.2017.04.002.
Guo YY, Liu YJ, Wang L, et al. Preliminary research on functional polymer liposome-entrapped gold nanoparticles as CT contrast agents[J]. Chin J Biological Pharms, 2017, 37 (4):5-8. doi: 10.3969/j.issn.1005-1678.2017.04.002[2] Rajkumar S, Prabaharan M. Theranostics Based on Iron Oxide and Gold Nanoparticles for Imaging-Guided Photothermal and Photodynamic Therapy of Cancer[J]. Curr Top Med Chem, 2017, 17 (16):1858-1871. DOI:10.2174/1568026617666161122120537 [3] Liu Y, Ai K, Lu L. Nanoparticulate X-ray computed tomography contrast agents:from design validation to in vivo applications[J]. Acc Chem Res, 2012, 45 (10):1817-1827. DOI:10.1021/ar300150c. [4] Lin W, Zhang X, Qian L, et al. Doxorubicin-Loaded Unimolecular Micelle-Stabilized Gold Nanoparticles as a Theranostic Nanoplatform for Tumor-Targeted Chemotherapy and Computed Tomography Imaging[J]. Biomacromolecules, 2017, 18 (12):3869-3880. DOI:10.1021/acs.biomac.7b00810. [5] Sasidharan S, Bahadur D, Srivastava R. Albumin stabilized gold nanostars:A biocompatible nanoplatform for SERS, CT imaging and photothermal therapy of cancer[J]. Rsc Advances, 2016, 6 (87):84025-84034. DOI:10.1039/C6RA11405A. [6] 翟宏菊, 戴晓威, 曹爽, 等.金纳米粒子的合成、性质及其应用新进展[J].吉林师范大学学报(自然科学版), 2017, 38 (2):13-16. DOI:10.16862/j.cnki.issn1674-3873.2017.02.003.
Zhai HJ, Dai XW, Cao S. New Progress of Synthesis, Properties and Applications of Gold Nanoparticles[J]. J Jilin Normal Univ (Natural Science Edition), 2017, 38 (2):13-16. doi: 10.16862/j.cnki.issn1674-3873.2017.02.003[7] 余建明.实用医学影像技术[M].人民卫生出版社, 2015:501.
Yu JM. Practical medical imaging technology[M]. People's health press, 2015:501.[8] Beik J, Jafariyan M, Montazerabadi A, et al. The benefits of folic acid-modified gold nanoparticles in CT-based molecular imaging: radiation dose reduction and image contrast enhancement[J/OL]. Artif Cells Nanomed Biotechnol, 2017: 1-9[2018-01-05]. https://www.ncbi.nlm.nih.gov/pubmed/29233015. DOI:10.1080/21691401. 2017. 1408019. [9] Seibert JA, Boone JM. X-ray imaging physics for nuclear medicine technologists. Part 2:X-ray interactions and image formatio[J]. J Nucl Med Technol, 2005, 33 (1):3-18. [10] Kang S, Eom J, Kim B, et al. Evaluation of gold K-edge imaging using spectral computed tomography with a photon-counting detector:A Monte Carlo simulation study[J]. Optik-Inter J Light Electron Optics, 2017, 140:253-260. DOI:10.1016/j.ijleo.2017.04. 062. [11] 李锋坦, 李东, 张云亭.管电压对CT值测量、辐射剂量及图像质量影响的模型研究[J].中华放射学杂志, 2013, 47 (5):458-461. DOI:10.3760/cma.j.issn.1005-1201.2013.05.016.
Li FT, Li D, Zhang YT. Influence of tube voltage on CT attenuation, radiation dose, and image quality:phantom study[J]. Chin J Radiol, 2013, 47 (5):458-461. doi: 10.3760/cma.j.issn.1005-1201.2013.05.016