Observational Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Mar 28, 2017; 9(3): 143-147
Published online Mar 28, 2017. doi: 10.4329/wjr.v9.i3.143
Computed tomography pulmonary angiography using a 20% reduction in contrast medium dose delivered in a multiphasic injection
Mitchell Chen, Gaith Mattar, Jamal A Abdulkarim
Mitchell Chen, Jamal A Abdulkarim, Department of Radiology, George Eliot Hospital NHS Trust, Nuneaton, Warwickshire CV10 7DJ, United Kingdom
Gaith Mattar, Department of Radiology, University Hospitals Birmingham NHS Trust, Birmingham B15 2TH, United Kingdom
Author contributions: Abdulkarim JA designed the experiment; Chen M and Abdulkarim JA conducted literature research; Mattar G and Abdulkarim JA performed the data collection; Chen M analysed the data; Chen M and Abdulkarim JA prepared the manuscript.
Institutional review board statement: The study was reviewed and approved by the George Eliot Hospital NHS Trust Directorate of Audit and Research.
Informed consent statement: Individual consent from patients was not obtained as this is retrospective observational study. All patient data were fully anonymised.
Conflict-of-interest statement: Chen M declares no conflict of interest. Mattar G declares no conflict of interest. Abdulkarim JA declares no conflict of interest.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at jamal.abdulkarim@geh.nhs.uk. Consent was not obtained for data sharing but the presented data are anonymised and risk of identification is low.
Open-Access: 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/
Correspondence to: Jamal A Abdulkarim, FRCR, Consultant Radiologist, Department of Radiology, George Eliot Hospital NHS Trust, College Street, Nuneaton, Warwickshire CV10 7DJ, United Kingdom. jamal.abdulkarim@geh.nhs.uk
Telephone: +44-247-6351351 Fax: +44-247-6865175
Received: October 5, 2016
Peer-review started: October 9, 2016
First decision: November 29, 2016
Revised: December 30, 2016
Accepted: January 16, 2017
Article in press: January 18, 2017
Published online: March 28, 2017
Processing time: 170 Days and 7 Hours
Abstract
AIM

To evaluate the feasibility of reducing the dose of iodinated contrast agent in computed tomography pulmonary angiography (CTPA).

METHODS

One hundred and twenty-seven patients clinically suspected of having pulmonary embolism underwent spiral CTPA, out of whom fifty-seven received 75 mL and the remaining seventy a lower dose of 60 mL of contrast agent. Both doses were administered in a multiphasic injection. A minimum opacification threshold of 250 Hounsfield units (HU) in the main pulmonary artery is used for assessing the technical adequacy of the scans.

RESULTS

Mean opacification was found to be positively correlated to patient age (Pearson’s correlation 0.4255, P < 0.0001) and independent of gender (male:female, 425.6 vs 450.4, P = 0.34). When age is accounted for, the study and control groups did not differ significantly in their mean opacification in the main (436.8 vs 437.9, P = 0.48), left (416.6 vs 419.8, P = 0.45) or the right pulmonary arteries (417.3 vs 423.5, P = 0.40). The number of sub-optimally opacified scans (the mean opacification in the main pulmonary artery < 250 HU) did not differ significantly between the study and control groups (7 vs 10).

CONCLUSION

A lower dose of iodine contrast at 60 mL can be feasibly used in CTPA without resulting in a higher number of sub-optimally opacified scans.

Keywords: Computed tomography pulmonary angiography; Contrast dose; Contrast induced nephropathy; Acute kidney disease; Contrast safety; Contrast dose reduction; Multiphasic injection

Core tip: Computed tomography pulmonary angiography scanning using a lower dose of contrast agent (60 mL) is proposed. Comparisons were made to patients in a control group who have received a standard dose of contrast medium (75 mL) at our Trust. There is no statistical difference in the degree of opacification in the main pulmonary artery between the two groups. The rate of rejection due to inadequate opacification is not affected by the reduction in contrast dose. The feasibility of using a reduced contrast dose at 60 mL is clearly demonstrated.