The perceptual influence of 2D synthesized images on 3D search

For some imaging modalities (e.g., Digital Breast Tomosynthesis, DBT), radiologists are provided, in addition to the 3D image stack, a 2D image known as C-view, a synthesized image from the corresponding 3D slices. An understanding of the functional perceptual interaction between the 2D image and the 3D search remains unexplored. We have yet to elucidate the basic perceptual mechanisms of visual search and attention that drive possible added benefits of incorporating the C-View image in the diagnostic process. We explore how the presence of a 2D synthesized view influences the detectability of signals and eye movements during 3D search in 1/f2.8 filtered noise backgrounds. Six trained observers searched for a microcalcification-like signal and a mass-like signal in 3D volumes (100 slices) with or without an additional 2D synthesized image (2D-S). The 2D-S was obtained by applying a high pass filter and a pixelwise maximum operation across the slices. We found that the detection and localization of small microcalcification-like signals in the 3D images improves when presented together with the 2D-S (p < 0.01). For larger mass-like signals, there was an improvement but not to the same extent as the microcalcification. Additionally, search times are significantly shorter for both signals when the 3D volume is accompanied by the 2D-S versus when used alone (p < 0.05). Eye movement analysis showed significantly fewer search errors in the 2D-S + 3D condition relative to the 3D condition for the microcalcification (p < .001) but not for the mass. The results suggest that a 2D-S allows an observer to efficiently identify suspicious locations, guide the search in 3D, and mitigate detrimental effects of peripheral vision on the detectability of small signals.