Investigating reading strategies and eye behaviours associated with high diagnostic performance when reading digital breast tomosynthesis (DBT) images

Purpose Digital breast tomosynthesis (DBT) exhibits increased sensitivity and specificity compared to 2D mammography (DM), but DBT images are complex and interpretation takes longer. Clinicians may fatigue or hit a cognitive limit sooner when reading DBT, potentially reducing diagnostic accuracy. Eye blink behaviour was investigated to explore fatigue and cognitive load. Methods Screeners (N=47) from five UK breast screening centres were eye tracked as they read 40 DBT cases (15 normal, 6 benign and 19 malignant), from November 2019-July 2021. Differences in diagnostic accuracy and blink behaviour were analysed over the course of the reading session. Blink rates and case durations were investigated by case malignancy and outcome using T-tests and ANOVAs (alpha=0.05). Results Blink rates were higher on malignant cases than on normal cases (p=0.004), and blink rates were higher for cases with true positive outcomes than for cases with true negative outcomes (p=0.013). Participants spent less time on malignant cases than normal or benign cases (ps=< 0.0001), whilst spending more time on cases with a false positive outcome than on cases with a true negative or true positive outcome (ps < 0.0001). No significant difference in blink rate or diagnostic performance by time through reporting session. Conclusion Differences in blink rate and time on case are associated with case malignancy and outcome, potentially reflecting varying cognitive demand and interpretation strategies. Further investigation into blinking during medical image interpretation may identify robust signals of cognition and fatigue that could be used for education and training purposes, whilst indicating optimal screening session duration.