Optimizing viewing procedures of breast tomosynthesis image volumes using eye tracking combined with a free response human observer study

The purpose of this study was to evaluate four different viewing procedures as part of improving viewing conditions of breast tomosynthesis (BT) image volumes. The procedures consisted of free scroll volume browsing, and a combination of initial cine loops at three different frame rates (9, 14 and 25 fps) terminated upon request followed by free scroll volume browsing. Fifty-five normal BT image volumes in MLO view were collected. In these, simulated lesions (20 masses and 20 clusters of microcalcifications) were randomly inserted, creating four unique image sets for each procedure. Four readers interpreted the cases in a random order. Their task was to locate a lesion, mark and assign a five level confidence scale. The diagnostic accuracy was analyzed using Jackknife Free Receiver Operating Characteristics (JAFROC). Time efficiency and visual search behavior were also investigated using eye tracking. The results indicate that there was no statistically significant difference in JAFROC FOM between the different viewing procedures, however the medium cine loop speed seemed to be the preferred viewing procedure in terms of total analyze time and dwell time.