Quantitative evaluation of image quality in CT imaging using iodine and nanoparticle-based contrast agents

Abstract Background: Computed tomography (CT) relies on X-ray attenuation differences to distinguish tissues, often enhanced using contrast agents. Although iodine-based media are commonly used, they are limited by toxicity, rapid renal clearance, and risk of allergic reactions. Subsequently research has increasingly focused on high atomic number nanoparticles, such as bismuth and tantalum, which offer strong X- ray attenuation with reduced toxicity, making them promising alternatives to conventional iodine agents. Objective: The aim was to evaluate the potential of Bismuth nanoparticles (BiNPs) and Tantalum nanoparticles (TaNPs) as contrast agents compared to conventional iodine-based agents. Materials and methods: A Perspex phantom was designed which included wells/holes of varying size diameters into which solutions could be introduced. This was then used to test iodine-based contrast media (ICM), BiNPs and TaNPs contrast agents at a range of concentrations and nanoparticle sizes. CT Image quality was assessed in terms of image signal intensity, CNR, and image noise. Results: For all agents, lower tube voltage (kVp) increased both signal intensity and CNR, although this improvement came with elevated noise levels. For ICM, increased concentration significantly influenced image quality. For BiNPs, image quality improvements were obtained with increased particle size and concentration. Nanoparticles have a higher atomic number than iodine and are therefore theoretically expected to exhibit greater X-ray attenuation. However, this advantage was not observed in the present investigation. Across all contrast agents, the image quality metrics achieved with ICM was consistently superior (p < 0.001) to that obtained with nanoparticle-based contrast agents. Conclusion: This study demonstrates that optimising CT image quality requires careful alignment and subtle balancing between the intrinsic properties of contrast 3 agents and the selected acquisition parameters. Overall, these findings provide a robust quantitative basis for refining CT imaging protocols.<p></p>

Author dc:creator

• Amani Alsaeedi (21042749)

• CT image quality

Statement dc:rights

• All rights reserved
• Open Access after 2028-01-06

Identifier

10779/exe.32882006.v1

OAI identifier oai:identifier

oai:figshare.com:article/32882006