Radiologists' eye gaze when reading cranial CT images

Review of prospects and challenges of eye tracking in volumetric imaging

“…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.…”

“…48,54 Conversely, fixations that cover multiple slices were presumably not a problem in experiments where radiologists were only allowed to scroll in one direction, as the time they spent on each slice was relatively long to avoid missing something that they could not get back to. 50,51 Five of the studies where scrolling was allowed, distinguished between fixations and saccades, 49,52,56-58 but did not explicitly state how fixations were scored. For the majority of them, the relatively short fixation durations that are reported suggest that fixations were calculated per individual slice.…”

“…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.…”

“…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.…”

“…By contrast, only a limited number of studies have aimed at shedding light on the relationship between visual search, perception, cognition, and performance in the context of volumetric images: five experiments have explored radiologists' reading strategies of stimulus material that was acquired by a volumetric imaging technique, [45][46][47][48][49] while five other studies looked at the influence of expertise on gaze behavior, [50][51][52][53][54] four explored the implications of different workstation configurations on gaze, [55][56][57][58][59] and one study examined the presence of inattentional blindness in the interpretation of chest CT cases. 60 Finally, one study looked at the visual search characteristics of readers when using computer-aided detection in CT colonography presented in the fly through mode.…”