The effect of computer-aided detection markers on visual search and reader performance during concurrent reading of CT colonography

Abstract

• Visual gaze is attracted by computer-assisted detection (CAD) marks on polyps • Inexperienced readers' gaze is affected more by CAD than experienced readers. • CAD marks could mean that the unannotated endoluminal surface is relatively neglected. • Correct polyp identification is increased significantly by CAD.

Do prevalence expectations affect patterns of visual search and decision-making in interpreting CT colonography endoluminal videos?

“…We have shown previously that time to first pursuit of the polyp changes with reader experience and the presence of a computeraided detection marker; 29,30 in the present study, this metric was unchanged across prevalence scenarios. When no polyp was visible, readers tended to spend more time, proportionally, looking at peripheral screen regions in the 80% prevalence condition, but this effect is small and is not supported by changes in other visual search metrics.…”

Review of prospects and challenges of eye tracking in volumetric imaging

“…The studies that dealt with volumetric imaging material [45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61] used images suitable for a three-dimensional representation of the human body, however, the presentation of stimulus material differed between them. Eight of the studies presented all slices of a multislice case and allowed radiologists to scroll freely through these stacks; 49,52,[55][56][57][58][59][60] thus, radiologists could scroll back and forth for as long as they wanted to and also determine the pace of their movement through the stack.…”

“…In two experiments, the radiologists were presented with five consecutive slices of MRI and CT cases, but they were only able to scroll in the forward direction, meaning that once they had chosen to scroll on, they were not able to return to a previous slice. 50,51 Four studies chose to present CT colonography fly-through videos rather than individual slices, 46,47,53,61 which means that all radiologists who took part in the study saw the slices being presented at the same pace and were unable to adjust the rate or scroll back to a location that was presented earlier.…”

“…For the majority of them, the relatively short fixation durations that are reported suggest that fixations were calculated per individual slice. 49,[56][57][58] Interestingly, six of the studies omitted the calculation of fixations and saccades altogether [45][46][47]60,61 and used raw data instead. While there is no definite right or wrong in the detection of events in eye tracking data, there are problems associated with calculating fixations per slice and the use of raw data: as aforementioned, the use of raw data does not account for saccadic suppression and for this reason, samples are included in the analysis that do not represent the intake of visual information.…”

“…Locations of possible polyps were marked by small dots in the videos of the colon and visual search in these videos was compared to visual search in the same videos in the absence of the cues. 61 Considering that volumetric imaging modalities, such as CT, have been used in the clinical practice since the 1970s, it seems surprising that few papers that apply eye tracking to volumetric imaging data seem to have been published. This low amount of previously published research is especially surprising since eye tracking research has flourished in some fields, such as conventional mammography and chest radiography.…”