Nano-Sized CT Contrast Agents

• Published in: Advanced materials (Weinheim) Vol. 25; no. 19; pp. 2641 - 2660
• Main Authors: Lee, Nohyun, Choi, Seung Hong, Hyeon, Taeghwan
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 21.05.2013; WILEY‐VCH Verlag
• Subjects: Circulation; computed tomography; contrast agent; Contrast agents; Contrast Media - chemical synthesis; Imaging; in vivo imaging; Lanthanides; Nanocomposites; Nanomaterials; Nanomedicine - trends; nanoparticle; Nanoparticles - chemistry; Nanoparticles - ultrastructure; Nanostructure; Tomography, X-Ray Computed - trends; X-ray; X-rays
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.201300081

Computed tomography (CT) is one of the most widely used clinical imaging modalities. In order to increase the sensitivity of CT, small iodinated compounds are used as injectable contrast agents. However, the iodinated contrast agents are excreted through the kidney and have short circulation times. This rapid renal clearance not only restricts in vivo applications that require long circulation times but also sometimes induces serious adverse effects related to the excretion pathway. In addition, the X‐ray attenuation of iodine is not efficient for clinical CT that uses high‐energy X‐ray. Due to these limitations, nano‐sized iodinated CT contrast agents have been developed that can increase the circulation time and decrease the adverse effects. In addition to iodine, nanoparticles based on heavy atoms such as gold, lanthanides, and tantalum are used as more efficient CT contrast agents. In this review, we summarize the recent progresses made in nano‐sized CT contrast agents. Various nano‐sized materials are developed as novel CT contrast agents to overcome the limitations of current iodinated agents. These novel agents using heavy atoms such as gold, tantalum, lanthanides, and bismuth provide more efficient X‐ray contrast effects, and their long‐circulation time and facile surface modification allow a variety of applications including targeted imaging, angiography, multimodal imaging, and simultaneous diagnosis and therapy.