Aims and objectives
Intravenous iodinated contrast agents are high atomic number materials that enhance the image quality in CT imaging by increasing the image contrast.
contrast agents are used in 60% of the CT scans .
Several studies have investigated the effect of contrast agents on the absorbed radiation dose in CT ,
In a study,
increase in the absorbed doses were reported by considering the mass energy-absorption coefficients of blood and iodine and the photon energy spectrum...
Methods and materials
Validation of the Monte Carlo simulation software: We validated the Monte Carlo (MC) software environment (ImpactMC,
Germany) for our CT scanner (GE revelation CT scanner).
Dose was measured in each hole of the CTDI phantom in an axial acquisition for 70,
120 and 140 kVp,
and 120 mAs.
and spectrum were implemented in the MC software.
MC simulations were performed with 2×10 9 number of photons.
Presence of contrast agent has an impact on the absorbed radiation dose: The absorbed dose (D) in the region of interest of syringes rises with the increase in the iodine concentration (Fig.
In the clinical range of iodine concentrations (< 20 mg/ml),
the increase in dose can be accurately described by a linear function; however,
the trend deviates from the linear behavior as the iodine concentration increases.
For the clinical range of iodine concentrations following equations were...
In contrast-enhanced CT,
the presence of contrast agent increases the absorbed dose in organs and tissues.
The dose increase approximates a linear trend for a clinical range of iodine concentrations (< 20 mg/ml).
Results of simulations on a virtual aorta model shows the net physical effect of iodine concentration on the absorbed dose.
The agreement between the simulated dose results of the experimental and the virtual aorta models demonstrate the reliability of our simulations.
Sc. UZ Brussel,
University of VUB,
Department of Radiology Avenue du Laerbeek 101,
Belgium Phone: +32485628431 Email: Mahta.Mazloumi@vub.be
“The Effect of Contrast Material on Radiation Dose at CT: Part II.
A Systematic Evaluation across 58 Patient Models,” Radiology ,
Jost et al. ,
“The influence of x-ray contrast agents in computed tomography on the induction of dicentrics and gamma-H2AX foci in lymphocytes of human blood samples,” Phys.