Evidence-Based Medicine
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Oct 15, 2017; 9(10): 423-430
Published online Oct 15, 2017. doi: 10.4251/wjgo.v9.i10.423
Low-dose computed tomography with 4th-generation iterative reconstruction algorithm in assessment of oncologic patients
Davide Ippolito, Alessandra Silvia Casiraghi, Cammillo Talei Franzesi, Davide Fior, Franca Meloni, Sandro Sironi
Davide Ippolito, Alessandra Silvia Casiraghi, Cammillo Talei Franzesi, Davide Fior, Department of Diagnostic Radiology, “San Gerardo” Hospital, 20900 Monza, Italy
Davide Ippolito, Alessandra Silvia Casiraghi, Cammillo Talei Franzesi, Davide Fior, Franca Meloni, Sandro Sironi, School of Medicine, University of Milano-Bicocca, 20900 Monza, Italy
Sandro Sironi, Department of Diagnostic Radiology, “Papa Giovanni XXIII” Hospital, 24127 Bergamo, Italy
Author contributions: Ippolito D was guarantor of integrity of entire study; Ippolito D and Casiraghi AS contributed to study concepts; Ippolito D, Casiraghi AS and Franzesi CT contributed to study design; Franzesi CT and Fior D contributed to literature research; clinical studies; Ippolito D and Casiraghi AS contributed to data acquisition, data analysis/interpretation; Casiraghi AS contributed to statistical analysis; Ippolito D, Casiraghi AS and Meloni F contributed to manuscript preparation; Ippolito D and Sironi S contributed to manuscript definition of intellectual content; Ippolito D and Franzesi CT contributed to manuscript editing; all authors contributed to manuscript revision/review; Ippolito D contributed to manuscript final version approval.
Institutional review board statement: The study was reviewed and approved by the H. San Gerardo Institutional Review Board.
Informed consent statement: Every patient gave his informed consent, as required by our Institution.
Conflict-of-interest statement: All the authors are aware of the content of the manuscript and have no conflict of interest.
Data sharing statement: No additional data are available.
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: Davide Ippolito, MD, School of Medicine, University of Milano-Bicocca, Via Pergolesi 33, 20900 Monza, Italy. davide.atena@tiscalinet.it
Telephone: +39-2-64488265 Fax: +39-2-64488299
Received: May 13, 2017
Peer-review started: May 17, 2017
First decision: July 11, 2017
Revised: July 25, 2017
Accepted: August 16, 2017
Article in press: August 17, 2017
Published online: October 15, 2017
Abstract
AIM

To compare radiation dose and image quality of low-dose computed tomography (CT) protocol combined with hybrid-iterative reconstruction algorithm with standard-dose CT examinations for follow-up of oncologic patients.

METHODS

Fifty-one patients with known malignant diseases which underwent, during clinical follow-up, both standard-dose and low-dose whole-body CT scans were enrolled. Low-dose CT was performed on 256-row scanner, with 120 kV and automated mA modulation, and iterative reconstruction algorithm. Standard-dose CT was performed on 16-rows scanner, with 120 kV, 200-400 mAs (depending on patient weight). We evaluated density values and signal-to-noise ratio, along with image noise (SD), sharpness and diagnostic quality with 4-point scale.

RESULTS

Density values in liver, spleen and aorta were higher in low-dose images (liver 112.55 HU vs 103.90 HU, P < 0.001), as SD values in liver and spleen (liver 16.81 vs 14.41). Volumetric-Computed-Tomographic-Dose-Index (CTDIvol) and Dose-Length-Product (DLP) were significantly lower in low-dose CT as compared to standard-dose (DLP 1025.6 mGy*cm vs 1429.2 mGy*cm, P < 0.001) with overall dose reduction of 28.9%. Qualitative analysis did not reveal significant differences in image noise and diagnostic quality.

CONCLUSION

Automatic tube-current modulation combined with hybrid-iterative algorithm allows radiation dose reduction of 28.9% without loss of diagnostic quality, being useful in reducing dose exposure in oncologic patients.

Keywords: Computed tomography, Low-dose computed tomography, Tube current modulation, Oncologic imaging, Radiation dose

Core tip: Introduction of new generation of multidetector computed tomography (MDCT) scanner allowed thin-collimation scanning and high spatial resolution, and reducing at same time the delivered radiation dose to patients by using new iterative reconstruction algorithm. This new mathematical model approach permits to reduce the radiation dose, expecially in patients who undergo serial follow-up study for oncologic (staging and restaging) purpose. On these basis in our study we evaluated radiation dose and image quality of CT examinations in a population of oncologic patients undergoing follow-up examinations with a new generation MDCT scanner (256-rows) using automatic modulation of tube current and iterative reconstruction algorithm (DoseRight system).