Does administering iodine in radiological procedures increase patient doses?

Abstract

Adding iodine can result in values of localized absorbed dose increasing by more than an order of magnitude, but the total energy deposition is generally very modest (i.e., <10%). Their data show that adding iodine primarily changes the pattern of energy deposition in the irradiated region, rather than increasing patient doses per se.

Estimating Thyroid Doses From Modified Barium Swallow Studies

“…The dosimetry performed in this study did not consider the presence of barium in the patient, which may affect the resultant patient doses. A recent study (He et al, 2014) investigated the effect of adding iodine to patient doses, which is likely to be applicable to barium given the close similarity between Iodine (Z = 53; k-edge 33 keV) and barium (Z = 56; k-edge 37 keV). In this study, the addition of iodine was found to have negligible effects on absorbed tissue doses at locations that are in front of the added iodine, but that substantial dose reductions can occur at x-ray beam locations that are behind the added contrast material.…”

Investigations of CT Dose with Contrast Agent and Its Effects on the CTDI

“…A clinical study by Amaton et al [19] also identified that inclusion of iodine contrast media in CT scans results in direct dose enhancement specific to various organs ranging from 20% to 70%. In addition, a recent Monte Carlo simulation based study conducted by He et al [20] also demonstrated an increase in dose caused by micro-spheres containing contrast media in a modelled phantom. Whilst these studies indicate (or suggest) that contrast media does have both a direct and indirect impact on CT dose, there is a need to theoretically and experimentally examine and quantify the direct effects of contrast media on CTDI.…”

The impact of iodinated contrast media on intravascular and extravascular absorbed doses in X-ray imaging: A microdosimetric analysis

“…Three groups of researchers have investigated the impact of ICM on the absorbed dose to tissues other than the blood, from diagnostic x-ray procedures [6][7][8][9][10], albeit with very different approaches. Amato et al [6,7]…”

“…x-ray imaging have been published [6][7][8][9][10]. These have generally focused on macroscopic doses, i.e.…”

“…Sahbaee et al [10] did however, perform a simple microdosimetric analysis to determine the proportion of electron energy deposited outside blood vessels. They reported an ICM-associated increase in 'biologically relevant' dose to the kidneys of 27% while the increase in macroscopic kidney dose was 54%.The study by He et al[8] assumed iodine was restricted to a single sphere of water, embedded within a larger water sphere, of radius 14 cm, representing the patient. The energy imparted to the 'contrast sphere' was increased by a factor of 2.38, 2.21 and 1.63 at 10 mg/ml iodine concentrations, for contrast sphere diameters of 0.5 cm, 4.0 cm and 16.0 cm (60 keV mono-energetic x-ray beam).…”