Effects of various generations of iterative CT reconstruction algorithms on low-contrast detectability as a function of the effective abdominal diameter: A quantitative task-based phantom study.

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Version: Final published version
Serval ID
serval:BIB_6CB7F1F645C1
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Effects of various generations of iterative CT reconstruction algorithms on low-contrast detectability as a function of the effective abdominal diameter: A quantitative task-based phantom study.
Journal
Physica medica
Author(s)
Viry A., Aberle C., Racine D., Knebel J.F., Schindera S.T., Schmidt S., Becce F., Verdun F.R.
ISSN
1724-191X (Electronic)
ISSN-L
1120-1797
Publication state
Published
Issued date
04/2018
Peer-reviewed
Oui
Volume
48
Pages
111-118
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Abstract
To investigate how various generations of iterative reconstruction (IR) algorithms impact low-contrast detectability (LCD) in abdominal computed tomography (CT) for different patient effective diameters, using a quantitative task-based approach.
Investigations were performed using an anthropomorphic abdominal phantom with two optional additional rings to simulate varying patient effective diameters (25, 30, and 35 cm), and containing multiple spherical targets (5, 6, and 8 mm in diameter) with a 20-HU contrast difference. The phantom was scanned using routine abdominal protocols (CTDI <sub>vol</sub> , 5.9-16 mGy) on four CT systems from two manufacturers. Images were reconstructed using both filtered back-projection (FBP) and various IR algorithms: ASiR 50%, SAFIRE 3 (both statistical IRs), ASiR-V 50%, ADMIRE 3 (both partial model-based IRs), or Veo (full model-based IR). Section thickness/interval was 2/1 mm or 2.5/1.25 mm, except 0.625/0.625 mm for Veo. We assessed LCD using a channelized Hotelling observer with 10 dense differences of Gaussian channels, with the area under the receiver operating characteristic curve (AUC) as a figure of merit.
For the smallest phantom (25-cm diameter) and smallest lesion size (5-mm diameter), AUC for FBP and the various IR algorithms did not significantly differ for any of the tested CT systems. For the largest phantom (35-cm diameter), Veo yielded the highest AUC improvement (8.5%). Statistical and partial model-based IR algorithms did not significantly improve LCD.
In abdominal CT, switching from FBP to IR algorithms offers limited possibilities for achieving significant dose reductions while ensuring a constant objective LCD.
Keywords
Computed tomography, Iterative reconstruction algorithms, Low-contrast detectability, Mathematical model observers, Task-based image quality assessment
Pubmed
Web of science
Open Access
Yes
Create date
12/05/2018 9:46
Last modification date
20/08/2019 14:26
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