Solbak, MS, Henning, MK, England, A, Martinsen, AC, Aaløkken, TM and Johansen, S (2020) Impact of iodine concentration and scan parameters on image quality, contrast enhancement and radiation dose in thoracic CT. European Radiology Experimental, 4 (1). ISSN 2509-9280

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<jats:title>Abstract</jats:title> <jats:sec> <jats:title>Background</jats:title> <jats:p>We investigated the impact of varying contrast medium (CM) densities and x-ray tube potentials on contrast enhancement (CE), image quality and radiation dose in thoracic computed tomography (CT) using two different scanning techniques.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>Seven plastic tubes containing seven different CM densities ranging from of 0 to 600 HU were positioned inside a commercial chest phantom with padding, representing three different patient sizes. Helical scans of the phantom in single-source mode were obtained with varying tube potentials from 70 to 140 kVp. A constant volume CT dose index (CTDIvol) depending on phantom size and automatic dose modulation was tested. CE (HU) and image quality (contrast-to-noise ratio, CNR) were measured for all combinations of CM density and tube potential. A reference threshold of CE and kVp was defined as ≥ 200 HU and 120 kVp.</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>For the medium-sized phantom, with a specific CE of 100–600 HU, the diagnostic CE (200 HU) at 70 kVp was ~ 90% higher than at 120 kVp, for both scan techniques (<jats:italic>p</jats:italic> &lt; 0.001). Changes in CM density/specific HU together with lower kVp resulted in significantly higher CE and CNR (<jats:italic>p</jats:italic> &lt; 0.001). When changing only the kVp, no statistically significant differences were observed in CE or CNR (<jats:italic>p</jats:italic> ≥ 0.094), using both dose modulation and constant CTDIvol.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>For thoracic CT, diagnostic CE (≥ 200 HU) and maintained CNR were achieved by using lower CM density in combination with lower tube potential (&lt; 120 kVp), independently of phantom size.</jats:p> </jats:sec>

Item Type: Article
Additional Information: Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit
Uncontrolled Keywords: Contrast media, Phantoms (imaging), Radiation dosage, Thorax, Tomography (x-ray computed)
Subjects: Q Science > Q Science (General)
Q Science > QM Human anatomy
T Technology > T Technology (General)
Divisions: Faculty of Medicine and Health Sciences > School of Allied Health Professions
Depositing User: Symplectic
Date Deposited: 17 Sep 2020 13:59
Last Modified: 17 Sep 2020 13:59

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