Eye tracking in digital pathology: Identifying expert and novice patterns in visual search behaviour

The National Health Service (NHS) in the United Kingdom (UK) is on the verge of transitioning into the use of digital pathology. Technological advancements such as whole slide imaging (WSI), whereby microscopy slides are scanned using a high throughput device to produce digital copies of the slides, has enabled such revolution possible. These digital images enable viewing using image viewer systems on computer monitors, hence making eye tracking studies feasible. The Digital Pathology trial has been set up to evaluate the use of virtual microscopy in the UK. As part of this trial, we conducted two pilot studies as our initial evaluation prior to larger scale studies. In this study, we present the initial findings from our latest pilot study which aims to characterise visual search patterns in pathologists of varying experience. This study was conducted with three pathologists at different stages of their careers, looking at core needle biopsy of breast specimens. We found that the more experienced pathologist had shorter reading duration and had lesser number of fixations consistent with our previous pilot study findings. However, this study did not reproduce any significant finding on magnification pattern. Further work would require a larger sample size to reach more certainty.