Tachibana Y, Otsuka K, Shiroo T, Asayama Y. Equilibrium phase images of the liver using a contrast-enhancement boost instead of the portal vein phase. World J Radiol 2025; 17(2): 102462 [DOI: 10.4329/wjr.v17.i2.102462]
Corresponding Author of This Article
Yoshiki Asayama, Department of Radiology, Faculty of Medicine, Oita University, 1-1, Idaigaoka, Hasama-machi, Yufu 879-5593, Oita, Japan. asayama@oita-u.ac.jp
Research Domain of This Article
Radiology, Nuclear Medicine & Medical Imaging
Article-Type of This Article
Retrospective Study
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Yuji Tachibana, Department of Radiological Sciences, Faculty of Medicine, Fukuoka International University of Health and Welfare, Fukuoka 814-0001, Japan
Yuji Tachibana, Kenichiro Otsuka, Yoshiki Asayama, Department of Radiology, Faculty of Medicine, Oita University, Yufu 879-5593, Oita, Japan
Tomoaki Shiroo, Department of Radiology, Division of Medical Technology, Oita University Hospital, Yufu 879-5593, Oita, Japan
Author contributions: Tachibana Y and Asayama Y designed the study; Tachibana Y contributed to the writing of the manuscript; Tachibana Y, Otsuka K, and Asayama Y contributed to the analysis of the data; Shiroo T contributed to data collection; and all authors read and approved the final manuscript.
Institutional review board statement: This study was approved by the Medical Ethics Committee of Oita University Hospital Institutional Review Board, approval No. 2643.
Informed consent statement: All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at asayama@oita-u.ac.jp. Participants gave informed consent was not obtained but the presented data are anonymized and risk of identification is low.
Open Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Yoshiki Asayama, Department of Radiology, Faculty of Medicine, Oita University, 1-1, Idaigaoka, Hasama-machi, Yufu 879-5593, Oita, Japan. asayama@oita-u.ac.jp
Received: October 21, 2024 Revised: January 22, 2025 Accepted: February 14, 2025 Published online: February 28, 2025 Processing time: 131 Days and 1.7 Hours
Abstract
BACKGROUND
Three-phase dynamic computed tomography imaging is particularly useful in the liver region. However, dynamic imaging with contrast media has the disadvantage of increased radiation exposure due to multiple imaging sessions. We hypothesized that the contrast enhancement boost (CE-boost) technique could be used to enhance the contrast in equilibrium phase (EP) images and produce enhancement similar to that of portal vein phase (PVP) images, and if this is possible, EP imaging could play the same role as PVP imaging. We also speculated that this might allow the conversion of three-phase dynamic imaging to biphasic dynamic imaging, reducing patients’ radiation exposure.
AIM
To determine if the CE-boost of EP, CE-boost (EP) is useful compared to a conventional image.
METHODS
We retrospectively analyzed the cases of 52 patients who were diagnosed with liver cancer between January 2016 and October 2022 at our institution. From these computed tomography images, CE-boost images were generated from the EP and plane images. We compared the PVP, EP, and CE-boost (EP) for blood vessels and hepatic parenchyma based on the contrast-to-noise ratio (CNR), signal-to-noise ratio, and figure-of-merit (FOM). Visual assessments were also performed for vessel visualization, lesion conspicuity, and image noise.
RESULTS
The CE-boost (EP) images showed significant superiority compared to the PVP images in the CNR, signal-to-noise ratio, and FOM except regarding the hepatic parenchyma. No significant differences were detected in CNR or FOM comparisons within the hepatic parenchyma (P = 0.62, 0.67). The comparison of the EP and CE-boost (EP) images consistently favored CE-boost (EP). Regarding the visual assessment, the CE-boost (EP) images were significantly superior to the PVP images in lesion conspicuity, and the PVP in image noise. The CE-boost (EP) images were significantly better than the EP images in the vessel visualization of segmental branches of the portal vein and lesion conspicuity, and the EP in image noise.
CONCLUSION
The image quality of CE-boost (EP) images was comparable or superior to that of conventional PVP and EP. CE-boost (EP) images might provide information comparable to the conventional PVP.
Core Tip: The aim of this study was to evaluate the contrast enhancement boost method of enhancing equilibrium phase (EP) computed tomography images in liver imaging compared to portal venous phase and EP images, and to reduce radiation dose by switching from triphasic to biphasic imaging. The results show that contrast enhancement boost of EP images have the same or better image quality as portal venous phase images, suggesting that a reduction in radiation dose is possible.
