Radiological Physics and Technology

, Volume 2, Issue 1, pp 33–39

Numerical evaluation of the effectiveness of colloidal gold as a contrast agent

Authors

    • Nuclear Professional School, Graduate School of EngineeringThe University of Tokyo
  • Meiling Jiang
    • Department of Bioengineering, Graduate School of EngineeringThe University of Tokyo
  • Kazue Mizuno
    • Department of Nuclear Engineering and Management, Graduate School of EngineeringThe University of Tokyo
  • Mitsuru Uesaka
    • Nuclear Professional School, Graduate School of EngineeringThe University of Tokyo
Article

DOI: 10.1007/s12194-008-0041-2

Cite this article as:
Yusa, N., Jiang, M., Mizuno, K. et al. Radiol Phys Technol (2009) 2: 33. doi:10.1007/s12194-008-0041-2

Abstract

Monte Carlo numerical simulations were conducted to evaluate the effectiveness of colloidal gold as a contrast agent. The simulations were conducted using a simple configuration, modeling a phantom to maintain the generality of the results, and the effects of the mass percentage of gold accumulated inside the tumor and the energy of the irradiating X-rays were evaluated, as well as other information, such as the energy spectrum of the photons reaching the detector and the change in the energy deposited inside the phantom. The contrast of the X-ray image due to the layer is calculated from the total energy of photons transmitted to the back surface of the phantom. The simulation revealed that colloidal gold with a mass percentage of 1.0% provided an image for which the contrast was almost 70% of that for bone of the same thickness when X-rays from conventional X-ray tubes were considered. Monochromatic X-rays of 44, 66, and 88 keV, which simulated the Compton scattering monochromatic X-ray source being developed, were also evaluated. X-rays at the first two energies did not have a significant advantage over the rays from the X-ray tubes. For colloidal gold with a mass percentage of 1.0%, the 88 keV monochromatic X-ray produced an image contrast that was about 10% higher than the contrast for bone of the same thickness, as suggested by the K-absorption energy of gold. However, the improvement was not large considering the difficulty involved in making such a high-energy monochromatic X-ray source available.

Keywords

Gold nanoparticlesMonte Carlo simulationRadiotherapyImaging agentMonochromatic X-raysCompton scattering

Copyright information

© Japanese Society of Radiological Technology and Japan Society of Medical Physics 2008