Cormode David P, Naha Pratap C, Fayad Zahi A
Departments of Radiology, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA, 19104, USA.
Contrast Media Mol Imaging. 2014 Jan-Feb;9(1):37-52. doi: 10.1002/cmmi.1551.
Computed tomography (CT) is an X-ray-based whole-body imaging technique that is widely used in medicine. Clinically approved contrast agents for CT are iodinated small molecules or barium suspensions. Over the past seven years there has been a great increase in the development of nanoparticles as CT contrast agents. Nanoparticles have several advantages over small molecule CT contrast agents, such as long blood-pool residence times and the potential for cell tracking and targeted imaging applications. Furthermore, there is a need for novel CT contrast agents, owing to the growing population of renally impaired patients and patients hypersensitive to iodinated contrast. Micelles and lipoproteins, a micelle-related class of nanoparticle, have notably been adapted as CT contrast agents. In this review we discuss the principles of CT image formation and the generation of CT contrast. We discuss the progress in developing nontargeted, targeted and cell tracking nanoparticle CT contrast agents. We feature agents based on micelles and used in conjunction with spectral CT. The large contrast agent doses needed will necessitate careful toxicology studies prior to clinical translation. However, the field has seen tremendous advances in the past decade and we expect many more advances to come in the next decade.
计算机断层扫描（CT）是一种基于X射线的全身成像技术，在医学中广泛应用。临床上批准用于CT的造影剂是碘化小分子或钡剂悬浮液。在过去七年中，作为CT造影剂的纳米颗粒的开发有了大幅增长。纳米颗粒相对于小分子CT造影剂具有若干优势，例如较长的血池停留时间以及细胞追踪和靶向成像应用的潜力。此外，由于肾功能受损患者和对碘化造影剂过敏患者的数量不断增加，需要新型CT造影剂。胶束和脂蛋白（一类与胶束相关的纳米颗粒）已特别被用作CT造影剂。在本综述中，我们讨论CT图像形成的原理以及CT对比度的产生。我们讨论了开发非靶向、靶向和细胞追踪纳米颗粒CT造影剂的进展。我们重点介绍基于胶束并与光谱CT结合使用的造影剂。所需的大剂量造影剂将需要在临床转化之前进行仔细的毒理学研究。然而，该领域在过去十年中取得了巨大进展，我们预计在未来十年还会有更多进展。
