Using a NPWE model observer to assess suitable image quality for a digital mammography quality assurance programme

Monnin, Pascal; Bochud, François; Verdun, Francis R.

doi:10.1093/rpd/ncq010

Cited by 5 publications

(3 citation statements)

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“…Our CSF results are also relevant to an existing literature on “eye-filtered” models of detection (Bouwman, van Engen, Dance, Young, & Veldkamp, 2014 ; Burgess, 1994 ; Monnin, Bochud, & Verdun, 2010 ; Monnin, Marshall, Bosmans, Bochud, & Verdun, 2011 ; Van Peteghem, Bosmans, & Marshall, 2016 ) These models use a CSF function to modify a simple matched-filter target detector. Most of these use the CSF function suggested by Burgess ( 1994 ), which is based on earlier works in vision science (Kelly, 1975 ; Wilson & Giese, 1977 ) that did not account for any form of textural adaptation.…”

Section: Discussionsupporting

confidence: 60%

Visual adaptation and the amplitude spectra of radiological images

et al. 2018

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We examined how visual sensitivity and perception are affected by adaptation to the characteristic amplitude spectra of X-ray mammography images. Because of the transmissive nature of X-ray photons, these images have relatively more low-frequency variability than natural images, a difference that is captured by a steeper slope of the amplitude spectrum (~ − 1.5) compared to the ~ 1/f (slope of − 1) spectra common to natural scenes. Radiologists inspecting these images are therefore exposed to a different balance of spectral components, and we measured how this exposure might alter spatial vision. Observers (who were not radiologists) were adapted to images of normal mammograms or the same images sharpened by filtering the amplitude spectra to shallower slopes. Prior adaptation to the original mammograms significantly biased judgments of image focus relative to the sharpened images, demonstrating that the images are sufficient to induce substantial after-effects. The adaptation also induced strong losses in threshold contrast sensitivity that were selective for lower spatial frequencies, though these losses were very similar to the threshold changes induced by the sharpened images. Visual search for targets (Gaussian blobs) added to the images was also not differentially affected by adaptation to the original or sharper images. These results complement our previous studies examining how observers adapt to the textural properties or phase spectra of mammograms. Like the phase spectrum, adaptation to the amplitude spectrum of mammograms alters spatial sensitivity and visual judgments about the images. However, unlike the phase spectrum, adaptation to the amplitude spectra did not confer a selective performance advantage relative to more natural spectra.Electronic supplementary materialThe online version of this article (10.1186/s41235-018-0089-4) contains supplementary material, which is available to authorized users.

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Section: Discussionsupporting

confidence: 60%

Visual adaptation and the amplitude spectra of radiological images

et al. 2018

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“…These standards should address all aspects in the mammography examination, including equipment, performance, provider profile, and healthcare staff. Monitoring the quality standards provides opportunities to improve practice through a feedback mechanism that allows the identification of sub-optimal practice, and can suggest difficulties, training needs, and challenges [4–10]. …”

Section: Introductionmentioning

confidence: 99%

European radiographers’ challenges from mammography education and clinical practice – an integrative review

Metsälä

Meystre²,

Jorge³

et al. 2017

Insights Imaging

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ObjectivesThis study aims to identify European radiographers’ challenges in clinical performance in mammography and the main areas of mammography that require more and better training.MethodsAn extensive search was performed to identify relevant studies focused on clinical practice, education and training in mammography published between January 2010 and December 2015 in the English language. The data were analysed by using deductive thematic analysis.ResultsA total of 27 full text articles were read, evaluating their quality. Sixteen articles out of 27 were finally selected for this integrative review. The main challenges of radiographers’ mammography education/training can be divided into three groups: training needs, challenges related to radiographers, and challenges related to the organization of education. The most common challenges of clinical performance in mammography among European radiographers involved technical performance, the quality of practices, and patient-centeredness.ConclusionsThe introduction of harmonized mammography guidelines across Europe may serve as an evidence-based tool to be implemented in practice and education. However, the variability in human and material resources as well as the different cultural contexts should be considered during this process.Teaching Points • Radiographers’ awareness of their professional identity and enhancing multiprofessional cooperation in mammography. • Radiographers’ responsibilities regarding image quality (IQ) and optimal breast imaging performance. • Patient-centred mammography services focusing on the psychosocial needs of the patient. • Challenges: positioning, QC-testing, IQ-assessment, optimization of breast compression, communication, teamwork, and patient-centred care. • Introduction of evidence-based guidelines in Europe to harmonize mammography practice and education.

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“…In projection images, it is common to use additive signal profiles to be detected. [31][32][33] However, in the breast parenchyma, the underlying attenuation coefficients-ignoring calcium-are essentially binary, depending on whether a voxel comprised adipose or glandular tissues. Adding additional density to this binary background would violate the binary nature of the tissue in regions where the lesion overlies glandular tissues.…”

Section: Iic Simulation Of Lesionsmentioning

confidence: 99%

Effect of slice thickness on detectability in breast CT using a prewhitened matched filter and simulated mass lesions

et al. 2012

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Purpose: Dedicated breast CT (bCT) is an emerging technology with the potential to improve the detection of breast cancer in screening and diagnostic capacities. Typically, the 3D volume reconstructed from the scanner is displayed as sectional images. The purpose of this study was to evaluate the effect of section thickness on the detectability of simulated masses using a prewhitened matched filter (PWMF) as a model observer. Methods: A breast CT scanner has been designed and fabricated in the authors' laboratory with more than 200 women imaged in IRB-approved phase I and phase II trials to date. Of these, 151 bilateral data sets were selected on the basis of low artifact content, sufficient breast coverage, and excluding cases with breast implants. BIRADS breast density ratings were available for 144 of these patients. Spherical mass lesions of diameter 1, 2, 3, 5, 11, and 15 mm were mathematically generated and embedded at random locations within the parenchymal region of each bCT volume. Microcalcifications were not simulated in this study. For each viewing plane (sagittal, axial, and coronal) and section thickness (ranging from 0.3 to 44 mm), section images of the breast parenchyma containing the lesion were generated from the reconstructed bCT data sets by averaging voxels over the length of the section. Using signal known exactly (SKE) model observer methodology, receiver operating characteristic (ROC) curve analysis was performed on each generated projected image using a PWMF based model observer. ROC curves were generated for each breast data set, and the area under the ROC curve (AUC) was evaluated as well as the sensitivity at 95% specificity. Results: For all lesion sizes, performance rises modestly to a peak before falling off substantially as section thickness increases over the range of the study. We find that the optimal section thickness tracks the size of the lesion to be detected linearly with a small positive offset and slopes ranging from 0.27 to 0.44. No significant differences were observed between left and right breasts. Performance measures are negatively correlated with measures of breast density, with an average correlation coefficient of À0.48 for the BIRADS breast density score and À0.81 for the proportion of glandular tissue in the breast interior. Conclusions: This study shows quantitatively how PWMF detection performance of a known lesion size is influenced by section thickness in dedicated breast CT. While the optimal section thickness is tuned to the size of the lesion being detected, overall performance is more robust for thin section images compared to thicker images.

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Using a NPWE model observer to assess suitable image quality for a digital mammography quality assurance programme

Cited by 5 publications

References 8 publications

Visual adaptation and the amplitude spectra of radiological images

Visual adaptation and the amplitude spectra of radiological images

European radiographers’ challenges from mammography education and clinical practice – an integrative review

Effect of slice thickness on detectability in breast CT using a prewhitened matched filter and simulated mass lesions

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