Prospective Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Jun 28, 2016; 8(6): 618-627
Published online Jun 28, 2016. doi: 10.4329/wjr.v8.i6.618
Assessment of sub-milli-sievert abdominal computed tomography with iterative reconstruction techniques of different vendors
Atul Padole, Nisha Sainani, Diego Lira, Ranish Deedar Ali Khawaja, Sarvenaz Pourjabbar, Roberto Lo Gullo, Alexi Otrakji, Mannudeep K Kalra
Atul Padole, Nisha Sainani, Diego Lira, Ranish Deedar Ali Khawaja, Sarvenaz Pourjabbar, Roberto Lo Gullo, Alexi Otrakji, Mannudeep K Kalra, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States
Nisha Sainani, Department of Radiology, Brigham and Women’s Hospital, Boston, MA 02115, United States
Author contributions: Padole A, Khawaja RDA and Pourjabbar S were involved in patient recruitment and objective measurement; Padole A and Kalra MK wrote the manuscript; Sainani N and Lira D were the readers of the study; Lo Gullo R and Otrakji A were involved in blinding of study; Kalra MK helped in consenting patients and designing the study.
Institutional review board statement: The Human Research Committee of our Institutional Review Board (IRB) approved this Health Insurance Portability and Accountability Act (HIPAA) compliant prospective clinical study.
Informed consent statement: All study participants provided informed written consent prior to study enrollment.
Conflict-of-interest statement: None of the authors have any pertinent financial disclosures.
Data sharing statement: All the study participants gave written informed consent for data sharing.
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: Atul Padole, MD, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 25 New Chardon St, 4th Floor, Boston, MA 02114, United States. apadole@mgh.harvard.edu
Telephone: +1-617-6435076 Fax: +1-617-6430111
Received: November 28, 2015
Peer-review started: November 30, 2015
First decision: December 28, 2015
Revised: January 8, 2016
Accepted: March 7, 2016
Article in press: March 9, 2016
Published online: June 28, 2016
Abstract

AIM: To assess diagnostic image quality of reduced dose (RD) abdominal computed tomography (CT) with 9 iterative reconstruction techniques (IRTs) from 4 different vendors to the standard of care (SD) CT.

METHODS: In an Institutional Review Board approved study, 66 patients (mean age 60 ± 13 years, 44 men, and 22 women) undergoing routine abdomen CT on multi-detector CT (MDCT) scanners from vendors A, B, and C (≥ 64 row CT scanners) (22 patients each) gave written informed consent for acquisition of an additional RD CT series. Sinogram data of RD CT was reconstructed with two vendor-specific and a vendor-neutral IRTs (A-1, A-2, A-3; B-1, B-2, B-3; and C-1, C-2, C-3) and SD CT series with filtered back projection. Subjective image evaluation was performed by two radiologists for each SD and RD CT series blinded and independently. All RD CT series (198) were assessed first followed by SD CT series (66). Objective image noise was measured for SD and RD CT series. Data were analyzed by Wilcoxon signed rank, kappa, and analysis of variance tests.

RESULTS: There were 13/50, 18/57 and 9/40 missed lesions (size 2-7 mm) on RD CT for vendor A, B, and C, respectively. Missed lesions includes liver cysts, kidney cysts and stone, gall stone, fatty liver, and pancreatitis. There were also 5, 4, and 4 pseudo lesions (size 2-3 mm) on RD CT for vendor A, B, and C, respectively. Lesions conspicuity was sufficient for clinical diagnostic performance for 6/24 (RD-A-1), 10/24 (RD-A-2), and 7/24 (RD-A-3) lesions for vendor A; 5/26 (RD-B-1), 6/26 (RD-B-2), and 7/26 (RD-B-3) lesions for vendor B; and 4/20 (RD-C-1) 6/20 (RD-C-2), and 10/20 (RD-C-3) lesions for vendor C (P = 0.9). Mean objective image noise in liver was significantly lower for RD A-1 compared to both RD A-2 and RD A-3 images (P < 0.001). Similarly, mean objective image noise lower for RD B-2 (compared to RD B-1, RD B-3) and RD C-3 (compared to RD C-1 and C-2) (P = 0.016).

CONCLUSION: Regardless of IRTs and MDCT vendors, abdominal CT acquired at mean CT dose index volume 1.3 mGy is not sufficient to retain clinical diagnostic performance.

Keywords: Adult, Computed tomographic imaging, Abdomen, Radiation dose

Core tip: We assessed the performance of abdominal computed tomography (CT) acquired at sub-milli-Sievert radiation dose to the standard of care CT. A total of 66 subjects were scanned on three different multi-detector CT scanners at sub-milli-Sievert radiation dose [or CT dose index volume (CTDIvol) of 1.3 mGy]. Images were reconstructed with vendor-specific and vendor-neutral iterative reconstruction techniques (IRTs). We compared the clinical diagnostic performance of vendor specific and vendor neutral IRTs at sub-milli-Sievert radiation dose to the standard of care CT. We found that regardless of the IRTs and multi-detector CT vendors, CTDIvol of 1.3 mGy or sub-mill-sievert radiation dose did not provide sufficient clinical diagnostic performance for abdominal CT.