A common cause for image retakes in mammography is lack of proper positioning. Image retake is a potential hazard of increased radiation exposure to patient, patient discomfort and pain. Therefore, a mammographer has to provide fast exams with fewer retakes. Although evaluation of how a mammographer is effectively positioning has been studied in many ways, little research has been conducted to analyze visual attention. In this study, eye tracking system was adopted to detect eye movements and locations within a participants' visual fields during positioning. Eye tracking system has been widely used for assessing technical skills and risk awareness, and for comparing the skills between experts and novices. Two skilled mammographers and two novices were recruited. Positioning related activities were divided into two phases: patient's observation and breast positioning. Breast positioning was sub-divided into three stages to compare visual attention between experts and novices using heatmap and gaze plot. Although the expert tended to check each point, the novices tended to have a relatively short gaze of the outer breast region was observed. In the future, a comparative evaluation using clinical images is necessary; however, the eye tracking system to visualize attention contributes to medical safety during positioning.
Keywords: eye tracking system; level of proficiency; mammography; positioning; visual attention.