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Objectives: To study how radiologists' perceived ability to interpret digital mammography (DM) images is affected by decreases in image quality. Methods: One view from 45 DM cases (including 30 cancers) was degraded to six levels each of two acquisition-related issues (lower spatial resolution and increased quantum noise) and three post-processing-related issues (lower and higher contrast and increased correlated noise) seen during clinical evaluation of DM systems. The images were shown to fifteen breast screening radiologists from five countries. Aware of lesion location, the radiologists selected the most-degraded mammogram (indexed from 1 (reference) to 7 (most degraded)) they still felt was acceptable for interpretation. The median selected index, per degradation type, was calculated separately for calcification and soft tissue (including normal) cases. Using the two-sided, non-parametric Mann-Whitney test, the median indices for each case and degradation type were compared. Results: Radiologists were not tolerant to increases (medians: 1.5 (calcifications) and 2 (soft tissue)) or decreases (median: 2, for both types) in contrast, but were more tolerant to correlated noise (median: 3, for both types). Increases in quantum noise were tolerated more for calcifications than for soft tissue cases (medians: 3 vs. 4, p = 0.02). Spatial resolution losses were considered less acceptable for calcification detection than for soft tissue cases (medians: 3.5 vs. 5, p = 0.001). Conclusions: Perceived ability of radiologists for image interpretation in DM was affected not only by image acquisition-related issues but also by image post-processing issues, and some of those issues affected calcification cases more than soft tissue cases. Key Points: • Lower spatial resolution and increased quantum noise affected the radiologists' perceived ability to interpret calcification cases more than soft tissue lesion or normal cases. • Post-acquisition image processing-related effects, not only image acquisition-related effects, also impact the perceived ability of radiologists to interpret images and detect lesions. • In addition to current practices, post-acquisition image processing-related effects need to also be considered during the testing and evaluation of digital mammography systems. [ABSTRACT FROM AUTHOR]

Purpose: Our purpose was to compare mammographic positioning quality of new (NR) versus experienced screening radiographers (ER) in the Netherlands.Methods and Materials: Before starting to work in breast screening, NR must complete an education programme including a theoretical course (four days), practical training (six weeks), and a portfolio-review of 50 mammographic screening examinations performed by the radiographer. Furthermore, Dutch screening has an extensive system of quality assurance, including an audit-review of positioning quality of mammograms by ER. We analysed 13,520 portfolio views (NR) and 14,896 audit views (ER) based on pre-specified criteria, e.g., depiction of inframammary angle.Results: Overall positioning was more adequate for NR than ER (CC views: 97% versus 86%, p = 0.00; MLO views: 92% versus 84%, p = 0.00). NR scored better for most of the CC-criteria and showed, for instance, less folds (inadequate: 10% versus 16%, p = 0.00). In contrast, NR encountered more difficulties for MLO views in, for example, depiction of infra-mammary angle (inadequate: 38% versus 34%, p = 0.00). Overall, mammograms from NR were more often considered adequate, because of less severe errors.Conclusion: NR perform better than ER in overall positioning technique. These results stress the need for continuous monitoring and training in breast screening programmes to keep positioning skills up to date.Key Points: • We evaluated positioning quality of new and experienced Dutch screening radiographers. • New radiographers outperform their experienced colleagues in mammographic positioning quality. • New radiographers make less severe errors compared to experienced colleagues. • There is a need for a continuous individual monitoring and feedback system. [ABSTRACT FROM AUTHOR]

Objectives: Differences in breast density between populations may explain part of the variation in regional breast cancer screening performance. This study aimed to determine whether regional differences in breast density distribution are present in the Dutch screening population.Methods: As part of the DENSE trial, mammographic density was measured using a fully-automated volumetric method. The regions in our study were based on the geographic coverage of 14 reading units representing a large part of the Netherlands. General linear models were used.Results: Four hundred eighty-five thousand and twenty-one screening participants with a median age of 60 years were included (2013-2014). The proportion of women with heterogeneously or extremely dense breasts ranged from 32.5% to 45.7% between regions. Mean percent dense volume varied between 6.51% (95% confidence interval [CI]: 6.46-6.55) and 7.68% (95% CI: 7.66-7.71). Age differences could not explain the variation. Socio-economic status (SES) was positively associated with volumetric density in all analyses (low SES: 6.95% vs. high SES: 7.63%; p trend  < 0.0001), whereas a potential association between urbanisation and breast density only became apparent after SES adjustment.Conclusion: There appears to be geographic variation in mammographic density in the Netherlands, emphasizing the importance of including breast density as parameter in the evaluation of screening performance.Key Points: • Mammographic density may affect regional breast cancer screening performance. • Volumetric breast density varies across screening areas. • SES is positively associated with breast density. • Implications of volumetric breast density differences need to be studied further. [ABSTRACT FROM AUTHOR]