Table of Contents Author Guidelines Submit a Manuscript

A corrigendum for this article has been published. To view the corrigendum, please click here.

Radiology Research and Practice
Volume 2019, Article ID 3512126, 9 pages
Research Article

Verification of the Dose Reduction Effect via Diluted Injection in Dual-Energy Computed Tomography Using a Human Blood Flow Phantom

1Graduate School of Healthcare Science, Suzuka University of Medical Science, 1001-1, Kishioka-cho, Suzuka, Mie 510-0293, Japan
2Department of Radiology, Saiseikai Kawaguchi General Hospital, 5-11-5, Nishikawaguchi, Kawaguchi, Saitama 332-0021, Japan

Correspondence should be addressed to Hironobu Tomita; pj.en.ten-os.7sj@006168ea

Received 17 January 2019; Accepted 6 March 2019; Published 1 April 2019

Academic Editor: Paul Sijens

Copyright © 2019 Hironobu Tomita and Koichi Shibata. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Purpose. We sought to examine the possibility of reducing the contrast medium dosage in dual-energy imaging using a saline-mixed injection with a virtual monochromatic energy method of dual-source computed tomography (CT). Methods. An X-ray CT (SOMATOM Definition Flash: Siemens, Nurnberg, Germany) was employed. The mixing ratio of contrast medium and saline was gradually changed by 10%, followed by a mixed injection into a dynamic blood flow phantom (Nemoto Kyorindo, Japan) which is a hemodynamic simulation phantom to obtain time-enhancement curves (TECs). Exactly 64 TECs were prepared for each mixing ratio by changing the energy from 40 to 75 keV for monoenergetic imaging. The relationship between the image standard deviation (SD) and the energy of the virtual monochromatic image was determined. Combinations of the mixing ratio and energy (keV), which can maintain high CT numbers and low image SDs for 3D imaging, were tested, and the reduction rate of the contrast medium was calculated. Results. The TECs for the mixed injection method changed linearly with the dilution rates. The mixing ratios were strongly correlated with the maximum CT number of the TEC (R2 = 0.98). Contrast CT numbers and image SDs increased by approximately 20% and 25%, respectively, as the energy decreased by 5 keV. The optimal conditions for reducing the contrast medium dose were a mixing ratio of 6:4 and 55 keV of energy. Conclusion. The virtual monochromatic energy method reduced the contrast medium dosage by up to 40% for three-dimensional CT-angio (3DCTA) tests.