title: The Effect of Contrast Material on Radiation Dose at CT: Part II. A Systematic Evaluation across 58 Patient Models.
abstract: Purpose To estimate the radiation dose as a result of contrast medium administration in a typical abdominal computed tomographic (CT) examination across a library of contrast material-enhanced computational patient models. Materials and Methods In part II of this study, first, the technique described in part I of this study was applied to enhance the extended cardiac-torso models with patient-specific iodine-time profiles reflecting the administration of contrast material. Second, the patient models were deployed to assess the patient-specific organ dose as a function of time in a typical abdominal CT examination using Monte Carlo simulation. In this hypothesis-generating study, organ dose refers to the total energy deposited in the unit mass of the tissue inclusive of iodine. Third, a study was performed as a strategy to anticipate the biologically relevant dose (absorbed dose to tissue) in highly perfused organs such as the liver and kidney. The time-varying organ-dose increment values relative to those for unenhanced CT examinations were reported. Results The results from the patient models subjected to the injection protocol indicated up to a total 53%, 30%, 35%, 54%, 27%, 18%, 17%, and 24% increase in radiation dose delivered to the heart, spleen, liver, kidneys, stomach, colon, small intestine, and pancreas, respectively. The biologically relevant dose increase with respect to the dose at an unenhanced CT examination was in the range of 0%-18% increase for the liver and 27% for the kidney across 58 patient models. Conclusion The administration of contrast medium increases the total radiation dose. However, radiation dose, while relevant to be included in estimating the risk associated with contrast-enhanced CT, may still not fully characterize the total biologic effects. Therefore, given the fact that many CT diagnostic decisions would be impossible without the use of iodine, this study suggests the need to consider the effect of iodinated contrast material on the organ doses to patients undergoing CT studies when designing CT protocols.©RSNA, 2017 Online supplemental material is available for this article.
authors.affiliation: From the Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705 (P.S., E.A., W.P.S., D.M., R.C.N., E.S.); and Department of Physics, North Carolina State University, Raleigh, NC (P.S.).
authors.forename: Pooyan
authors.initials: P
authors.lastname: Sahbaee
authors.affiliation: From the Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705 (P.S., E.A., W.P.S., D.M., R.C.N., E.S.); and Department of Physics, North Carolina State University, Raleigh, NC (P.S.).
authors.forename: Ehsan
authors.initials: E
authors.lastname: Abadi
authors.affiliation: From the Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705 (P.S., E.A., W.P.S., D.M., R.C.N., E.S.); and Department of Physics, North Carolina State University, Raleigh, NC (P.S.).
authors.forename: W Paul
authors.initials: WP
authors.lastname: Segars
authors.affiliation: From the Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705 (P.S., E.A., W.P.S., D.M., R.C.N., E.S.); and Department of Physics, North Carolina State University, Raleigh, NC (P.S.).
authors.forename: Daniele
authors.initials: D
authors.lastname: Marin
authors.affiliation: From the Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705 (P.S., E.A., W.P.S., D.M., R.C.N., E.S.); and Department of Physics, North Carolina State University, Raleigh, NC (P.S.).
authors.forename: Rendon C
authors.initials: RC
authors.lastname: Nelson
authors.affiliation: From the Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705 (P.S., E.A., W.P.S., D.M., R.C.N., E.S.); and Department of Physics, North Carolina State University, Raleigh, NC (P.S.).
authors.forename: Ehsan
authors.initials: E
authors.lastname: Samei
mesh_terms: D000328:Adult; D003287:Contrast Media / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D017613:Iodine Compounds / Q000493:pharmacokinetics; D008297:Male; D008954:Models, Biological; D011829:Radiation Dosage; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D017613:Iodine Compounds