Prospective Study
Copyright ©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Nov 28, 2024; 16(11): 668-677
Published online Nov 28, 2024. doi: 10.4329/wjr.v16.i11.668
Ultra-low-dose chest computed tomography with model-based iterative reconstruction in the analysis of solid pulmonary nodules: A prospective study
Patrick W O'Regan, Antonia Harold-Barry, Alexander T O'Mahony, Claire Crowley, Stella Joyce, Niamh Moore, Owen J O'Connor, Michael T Henry, David J Ryan, Michael M Maher
Patrick W O'Regan, Niamh Moore, David J Ryan, Michael M Maher, Department of Radiology, School of Medicine, University College Cork, Cork T12 AK54, Ireland
Antonia Harold-Barry, Alexander T O'Mahony, Stella Joyce, Owen J O'Connor, Michael M Maher, Department of Radiology, Cork University Hospital, Cork T12 DC4A, Ireland
Claire Crowley, Department of Radiology, Mercy University Hospital, Cork T12WE28, Ireland
Michael T Henry, Department of Respiratory Medicine, Cork University Hospital, Cork T12 DC4A, Ireland
Author contributions: Maher MM and Henry M designed the research study; O’Regan PW, Harrold-Barry A, O’Mahony AT, Crowley C, Joyce S, Moore N, O’Connor OJ and Ryan DJ collected and assembled the data; O’Regan PW, Harrold-Barry A and O’Mahony AT analysed the data and wrote the manuscript; Ryan DJ, Henry M and Maher MM supervised the study; all authors have read and agreed to the published version of the manuscript.
Institutional review board statement: The study was reviewed and approved by the Clinical Research and Ethics Committee Institutional Review Board (Approval No.ECM4(g)1/3/16 & ECM3(nnnn)9/3/21).
Clinical trial registration statement: This small prospective trial was registered with the local ethics institutional review board. Original approval PDF attached. It was not required to register the study with another governing body (i.e. an additional Clinical Trial Registration Statement is not applicable).
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: The authors declare no conflict of interest.
Data sharing statement: The datasets generated and analysed during the current study are available from the corresponding author on reasonable request.
CONSORT 2010 statement: The authors have read the CONSORT 2010 statement, and the manuscript was prepared and revised according to the CONSORT 2010 statement.
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: Patrick W O'Regan, Doctor, MBChB, MSc, Research Fellow, Department of Radiology, School of Medicine, University College Cork, College Road, Cork T12 AK54, Ireland. patrickoregan@ucc.ie
Received: June 19, 2024
Revised: October 10, 2024
Accepted: November 12, 2024
Published online: November 28, 2024
Processing time: 160 Days and 19.5 Hours
Abstract
BACKGROUND

Incidental pulmonary nodules are an increasingly common finding on computed tomography (CT) scans of the thorax due to the exponential rise in CT examinations in everyday practice. The majority of incidental pulmonary nodules are benign and correctly identifying the small number of malignant nodules is challenging. Ultra-low-dose CT (ULDCT) has been shown to be effective in diagnosis of respiratory pathology in comparison with traditional standard dose techniques. Our hypothesis was that ULDCT chest combined with model-based iterative reconstruction (MBIR) is comparable to standard dose CT (SDCT) chest in the analysis of pulmonary nodules with significant reduction in radiation dose.

AIM

To prospectively compare ULDCT chest combined with MBIR with SDCT chest in the analysis of solid pulmonary nodules.

METHODS

A prospective cohort study was conducted on adult patients (n = 30) attending a respiratory medicine outpatient clinic in a tertiary referral university hospital for surveillance of previously detected indeterminate pulmonary nodules on SDCT chest. This study involved the acquisition of a reference SDCT chest followed immediately by an ULDCT chest. Nodule identification, nodule characterisation, nodule measurement, objective and subjective image quality and radiation dose were compared between ULDCT with MBIR and SDCT chest.

RESULTS

One hundred solid nodules were detected on ULDCT chest and 98 on SDCT chest. There was no significant difference in the characteristics of correctly identified nodules when comparing SDCT chest to ULDCT chest protocols. Signal-to-noise ratio was significantly increased in the ULDCT chest in all areas except in the paraspinal muscle at the maximum cardiac diameter level (P < 0.001). The mean subjective image quality score for overall diagnostic acceptability was 8.9/10. The mean dose length product, computed tomography volume dose index and effective dose for the ULDCT chest protocol were 5.592 mGy.cm, 0.16 mGy and 0.08 mSv respectively. These were significantly less than the SDCT chest protocol (P < 0.001) and represent a radiation dose reduction of 97.6%.

CONCLUSION

ULDCT chest combined with MBIR is non-inferior to SDCT chest in the analysis of previously identified solid pulmonary nodules and facilitates a large reduction in radiation dose.

Keywords: Ultra-low dose computed tomography; Solid pulmonary nodules; Computed tomography methods; Radiation dosage; Adult human

Core Tip: Recent advancements in computed tomography (CT) hardware and software have facilitated the development of ultra-low-dose imaging protocols that have the potential to significantly reduce radiation dose while, crucially, maintaining image quality and diagnostic integrity. Previously identified indeterminate solid pulmonary nodules may be effectively monitored with ultra-low-dose CT chest with the added benefit of a large reduction in radiation dose.