Titre
Task-based quantification of image quality using a model observer in abdominal CT: a multicentre study.
Type
article
Institution
UNIL/CHUV/Unisanté + institutions partenaires
Périodique
Auteur(s)
Racine, D.
Auteure/Auteur
Ryckx, N.
Auteure/Auteur
Ba, A.
Auteure/Auteur
Becce, F.
Auteure/Auteur
Viry, A.
Auteure/Auteur
Verdun, F.R.
Auteure/Auteur
Schmidt, S.
Auteure/Auteur
Liens vers les personnes
Liens vers les unités
ISSN
1432-1084
Statut éditorial
Publié
Date de publication
2018-12
Volume
28
Numéro
12
Première page
5203
Dernière page/numéro d’article
5210
Peer-reviewed
Oui
Langue
anglais
Notes
Publication types: Journal Article ; Multicenter Study
Publication Status: ppublish
Publication Status: ppublish
Résumé
We investigated the variability in diagnostic information inherent in computed tomography (CT) images acquired at 68 different CT units, with the selected acquisition protocols aiming to answer the same clinical question.
An anthropomorphic abdominal phantom with two optional rings was scanned on 68 CT systems from 62 centres using the local clinical acquisition parameters of the portal venous phase for the detection of focal liver lesions. Low-contrast detectability (LCD) was assessed objectively with channelised Hotelling observer (CHO) using the receiver operating characteristic (ROC) paradigm. For each lesion size, the area under the ROC curve (AUC) was calculated and considered as a figure of merit. The volume computed tomography dose index (CTDI <sub>vol</sub> ) was used to indicate radiation dose exposure.
The median CTDI <sub>vol</sub> used was 5.8 mGy, 10.5 mGy and 16.3 mGy for the small, medium and large phantoms, respectively. The median AUC obtained from clinical CT protocols was 0.96, 0.90 and 0.83 for the small, medium and large phantoms, respectively.
Our study used a model observer to highlight the difference in image quality levels when dealing with the same clinical question. This difference was important and increased with growing phantom size, which generated large variations in patient exposure. In the end, a standardisation initiative may be launched to ensure comparable diagnostic information for well-defined clinical questions. The image quality requirements, related to the clinical question to be answered, should be the starting point of patient dose optimisation.
• Model observers enable to assess image quality objectively based on clinical tasks. • Objective image quality assessment should always include several patient sizes. • Clinical diagnostic image quality should be the starting point for patient dose optimisation. • Dose optimisation by applying DRLs only is insufficient for ensuring clinical requirements.
An anthropomorphic abdominal phantom with two optional rings was scanned on 68 CT systems from 62 centres using the local clinical acquisition parameters of the portal venous phase for the detection of focal liver lesions. Low-contrast detectability (LCD) was assessed objectively with channelised Hotelling observer (CHO) using the receiver operating characteristic (ROC) paradigm. For each lesion size, the area under the ROC curve (AUC) was calculated and considered as a figure of merit. The volume computed tomography dose index (CTDI <sub>vol</sub> ) was used to indicate radiation dose exposure.
The median CTDI <sub>vol</sub> used was 5.8 mGy, 10.5 mGy and 16.3 mGy for the small, medium and large phantoms, respectively. The median AUC obtained from clinical CT protocols was 0.96, 0.90 and 0.83 for the small, medium and large phantoms, respectively.
Our study used a model observer to highlight the difference in image quality levels when dealing with the same clinical question. This difference was important and increased with growing phantom size, which generated large variations in patient exposure. In the end, a standardisation initiative may be launched to ensure comparable diagnostic information for well-defined clinical questions. The image quality requirements, related to the clinical question to be answered, should be the starting point of patient dose optimisation.
• Model observers enable to assess image quality objectively based on clinical tasks. • Objective image quality assessment should always include several patient sizes. • Clinical diagnostic image quality should be the starting point for patient dose optimisation. • Dose optimisation by applying DRLs only is insufficient for ensuring clinical requirements.
PID Serval
serval:BIB_8914F1CC532F
PMID
Open Access
Oui
Date de création
2018-06-15T15:59:54.034Z
Date de création dans IRIS
2025-05-20T21:30:17Z
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Nom
29858638_BIB_8914F1CC532F.pdf
Version du manuscrit
published
Licence
https://creativecommons.org/licenses/by/4.0
Taille
1.21 MB
Format
Adobe PDF
PID Serval
serval:BIB_8914F1CC532F.P001
URN
urn:nbn:ch:serval-BIB_8914F1CC532F8
Somme de contrôle
(MD5):a32f9b82edbf99cfce5339414a41cbe8