The association of attentional foci and image interpretation accuracy in novices interpreting lung ultrasound images: an eye-tracking study

Abstract

It is unclear, where learners focus their attention when interpreting point-of-care ultrasound (POCUS) images. This study seeks to determine the relationship between attentional foci metrics with lung ultrasound (LUS) interpretation accuracy in novice medical learners. A convenience sample of 14 medical residents with minimal LUS training viewed 8 LUS cineloops, with their eye-tracking patterns recorded. Areas of interest (AOI) for each cineloop were mapped independently by two experts, and externally validated by a third expert. Primary outcome of interest was image interpretation accuracy, presented as a percentage. Eye tracking captured 10 of 14 participants (71%) who completed the study. Participants spent a mean total of 8 min 44 s ± standard deviation (SD) 3 min 8 s on the cineloops, with 1 min 14 s ± SD 34 s spent fixated in the AOI. Mean accuracy score was 54.0% ± SD 16.8%. In regression analyses, fixation duration within AOI was positively associated with accuracy [beta-coefficients 28.9 standardized error (SE) 6.42, P = 0.002). Total time spent viewing the videos was also significantly associated with accuracy (beta-coefficient 5.08, SE 0.59, P < 0.0001). For each additional minute spent fixating within the AOI, accuracy scores increased by 28.9%. For each additional minute spent viewing the video, accuracy scores increased only by 5.1%. Interpretation accuracy is strongly associated with time spent fixating within the AOI. Image interpretation training should consider targeting AOIs.

Fig. 1

Gaze plots of expert (green, top left) and novices (purple) in identifying the presence of a positive spine sign and the pleural effusion. Top right: gaze plot of a novice who scored 0% on the video with minimal gaze on the spine. Bottom left: gaze plot of a different novice who scored 50% on the video. Bottom right: gaze plot of a third novice who correctly identified both findings and scored 100%

Fig. 2

Scatter plot of image interpretation accuracy score, presented as a precent, vs. total fixation duration within areas of interest (seconds), with fitted line shown in black, and confidence interval for the mean shown in gray