Real space channelization for generic DBT system image quality evaluation with channelized Hotelling observer

Petrov, Dimitar; Cockmartin, Lesley; Marshall, Nicholas; Vancoillie, Liesbeth; Young, Kenneth C.; Bosmans, Hilde

doi:10.1117/12.2254385

Cited by 3 publications

(7 citation statements)

References 6 publications

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“…However, the slope and intercept seemed to differ per system, especially for the unshifted channel set. This finding is supported by the work of Petrov et al 27 where the linear fit of CHO and human detection performance also resulted in a different slope and intercept per system. For the shifted channel sets, this system dependency seemed to decrease.…”

Section: Discussionsupporting

confidence: 69%

“…Since we are interested in developing a robust QC procedure, we opted for a system‐independent choice of DoG channel sets. One of the key parts of the work presented here is a different concept of generating spatial channels, where the tuning of the DoG channel profiles was performed by altering the channel parameters such that the same channel profiles were used for all systems and conditions . For this reason, the DoG channel formulation was made pixel size independent and a shifting method was introduced to account for the signal location uncertainty.…”

Section: Discussionmentioning

confidence: 99%

“…One of the key parts of the work presented here is a different concept of generating spatial channels, where the tuning of the DoG channel profiles was performed by altering the channel parameters such that the same channel profiles were used for all systems and conditions. 27 For this reason, the DoG channel formulation was made pixel size independent and a shifting method was introduced to account for the signal location uncertainty. We explored different parameters that describe the DoG channels in literature and a new channel set was proposed based on the information captured by the power spectra of the channels and testing images.…”

Section: Discussionmentioning

confidence: 99%

“…In this study, the exact same frequency channels were used for both systems regardless of the pixel size of the different systems because human detectability is (largely) affected by the real signal size in millimeters. Since the CHO should be trained and tested with assumptions relevant to the spatial domain signals, the DoG channels were implemented such that they are system independent in the spatial domain, as shown in Fig. .…”

Section: Methodsmentioning

confidence: 99%

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Can a channelized Hotelling observer assess image quality in acquired mammographic images of an anthropomorphic breast phantom including image processing?

et al. 2019

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Purpose To study the feasibility of a channelized Hotelling observer (CHO) to predict human observer performance in detecting calcification‐like signals in mammography images of an anthropomorphic breast phantom, as part of a quality control (QC) framework. Methods A prototype anthropomorphic breast phantom with inserted gold disks of 0.25 mm diameter was imaged with two different digital mammography x‐ray systems at four different dose levels. Regions of interest (ROIs) were extracted from the acquired processed and unprocessed images, signal‐present and signal‐absent. The ROIs were evaluated by a CHO using four different formulations of the difference of Gaussian (DoG) channel sets. Three human observers scored the ROIs in a two‐alternative forced‐choice experiment. We compared the human and the CHO performance on the simple task to detect calcification‐like disks in ROIs with and without postprocessing. The proportion of correct responses of the human reader (PCH) and the CHO (PCCHO) was calculated and the correlation between the two was analyzed using a mixed‐effect regression model. To address the signal location uncertainty, the impact of shifting the DoG channel sets in all directions up to two pixels was evaluated. Correlation results including the goodness of fit (r2) of PCH and PCCHO for all different parameters were evaluated. Results Subanalysis by system yielded strong correlations between PCH and PCCHO, with r2 between PCH and PCCHO was found to be between 0.926 and 0.958 for the unshifted and between 0.759 and 0.938 for the shifted channel sets, respectively. However, the linear fit suggested a slight system dependence. PCCHO with shifted channel sets increased CHO performance but the correlation with humans was decreased. These correlations were not considerably affected by of the DoG channel set used. Conclusions There is potential for the CHO to be used in QC for the evaluation of detectability of calcification‐like signals. The CHO can predict the PC of humans in images of calcification‐like signals of two different systems. However, a global model to be used for all systems requires further investigation.

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Section: Discussionsupporting

confidence: 69%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Can a channelized Hotelling observer assess image quality in acquired mammographic images of an anthropomorphic breast phantom including image processing?

et al. 2019

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“…Differences in DBT scanning parameters (angular range, antiscatter grid use, reconstruction algorithms [6]), lead to strong differences in the appearance of DBT images between the various systems. Whether this translates into differences in task performance evaluated using a CHO is unclear, yet preliminary data [51] show that a CHO with Gabor channels generated in real space can be a starting point in this investigation.…”

Section: Tablementioning

confidence: 99%

Systematic approach to a channelized Hotelling model observer implementation for a physical phantom containing mass-like lesions: Application to digital breast tomosynthesis

et al. 2019

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Purpose: to develop a channelized model observer (CHO) that matches human reader (HR) scoring of a physical phantom containing breast simulating structure and mass lesion-like targets for use in quality control of digital breast tomosynthesis (DBT) imaging systems. Methods: A total of 108 DBT scans of the phantom was acquired using a Siemens Inspiration DBT system. The detectability of mass-like targets was evaluated by human readers using a 4-alternative forced choice (4-AFC) method. The percentage correct (PC) values were then used as the benchmark for CHO tuning, again using a 4-AFC method. Three different channel functions were considered: Gabor, Laguerre-Gauss and Difference of Gaussian. With regard to the observer template, various methods for generating the expected signal were studied along with the influence of the number of training images used to form the covariance matrix for the observer template. Impact of bias in the training process on the observer template was evaluated next, as well as HR and CHO reproducibility. Results: HR performance was most closely matched by 8 Gabor channels with tuned phase, orientation and frequency, using an observer template generated from training image data. Just 24 DBT image stacks were required to give robust CHO performance with 0% bias, although a bias of up to 33% in the training images also gave acceptable performance. CHO and HR reproducibility were similar (on average 3.2 PC versus 3.4 PC). Conclusions: The CHO algorithm developed matches human reader performance and is therefore a promising candidate for automated readout of phantom studies.

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Model and human observer reproducibility for detection of microcalcification clusters in digital breast tomosynthesis images of three-dimensionally structured test object

et al. 2019

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We compare the reproducibility of the human observers and a channelized Hotelling observer (CHO), when reading digital breast tomosynthesis (DBT) images of a physical phantom containing a breast simulating structured background and calcification clusters at three dose levels. The phantom is scanned 217 times on a Siemens Inspiration DBT system. Volumes of interest, with and without the calcification targets, are extracted and the human observers' percentage of correct (PC) scores is evaluated using a four-alternative forced choice method. A two-layer CHO is developed using the human observer results. The first layer consists of a localizing CHO that identifies the most conspicuous calcifications using two Laguerre-Gauss channels. Then a CHO with eight Gabor channels estimates the PC score for the calcification cluster. Observer reproducibility is estimated by bootstrapping, and the standard deviation (SD) is used as a figure of merit. The CHO closely approximated the human observer results for all the three dose levels with a correlation of >0.97. For the larger calcification cluster sizes, both observers have similar reproducibility, whereas the CHO is more reproducible for the smaller calcifications, with a maximum of 5.5 SD against 13.1 SD for the human observers. The developed CHO is a good candidate for automated reading of the calcification clusters of the structured phantom, with better reproducibility than the human readers for small calcifications.

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Real space channelization for generic DBT system image quality evaluation with channelized Hotelling observer

Cited by 3 publications

References 6 publications

Can a channelized Hotelling observer assess image quality in acquired mammographic images of an anthropomorphic breast phantom including image processing?

Can a channelized Hotelling observer assess image quality in acquired mammographic images of an anthropomorphic breast phantom including image processing?

Systematic approach to a channelized Hotelling model observer implementation for a physical phantom containing mass-like lesions: Application to digital breast tomosynthesis

Model and human observer reproducibility for detection of microcalcification clusters in digital breast tomosynthesis images of three-dimensionally structured test object

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