Differences in eye movements in chest X-ray diagnosis and exploration of effective diagnostic strategies: A study in annual medical checkup conditions

Abstract

During the process of medical interpretation and diagnosis in medical image, doctors’ attention allocations are various depending on individuals and cases. The process of diagnosing in the medical image involves complex interplay between visual perception and effective information acquisition strategies coupled with medical knowledge. It is difficult for doctors to explicitly explain their strategies because the process is often implicit. To date, precisely what attention allocation patterns and cognitive strategies in medical image reading, remains unknown.This study aims to uncover the doctor’s attention allocation and transition patterns in reading chest X-ray image, elicit diagnostic strategies based on doctor’s eye movements and interviews, and find the differences of diagnostic strategies between expert and novice doctors. Finally, prospective suggestions for leading novice doctors to an effective diagnostic strategy in reading X-ray image can be presented.We simulate the scenario of annual medical checkup using four patients’ cases, and recruit participants with diverse medical experiences and specialties in Tokyo Medical and Dental University Hospital to compare the differences of attention allocations between doctors. Doctors are asked to identify the lesion and give diagnostic decision to four cases. Their eye movements are recorded in the whole process by eye tracker. After completing all four cases, participants are asked to attend an interview session in which their eye movements are used as cues to elicit their diagnostic strategies. And two questionnaires are answered at last. Fixation duration, the number of fixations in each are of interest (AOI) are used to visualize doctors’ attention allocation and fixation transition patterns. Both qualitative and quantitative analysis are used to describe doctors’ diagnostic strategies and compare the differences between expert and novice doctors. Each doctor has personal characteristics when diagnosing. Doctors have a significant preference to read to current image. Doctors tend to pay more attention to areas where physiological structures overlap and where doctors think suspicious. As for diagnostic strategies, four typical patterns of change of diagnostic strategies in timeline are found. Furthermore, the differences are found between expert and novice doctors in attention allocation and the use of historical image.The effective diagnostic strategy is that performing the inspection routine of the current image separate with comparison with the historical image to avoid distracting and missing information. The comparison should focus on important areas and suspicious areas rather than the whole image. The suggested important areas are the lung apex, mediastinum, heart, left lung hilar and the lower lung field. The proposed effective strategies could be included in the medical education and new doctor training to improve novice doctors’ ability to diagnose by multiple images.