Division of Vascular Surgery, Department of Surgery, Wilson Centre for Research in Education, 1 Eaton S., Room 1-565, 200 Elizabeth Street, Toronto, Ontario M5G 2C4, Canada. raviparv@hotmail.com
Endovascular therapy has had a major effect on vascular surgery; surgeons perform tasks in three dimensions (3D) while viewing two-dimensional (2D) displays. This fundamental change in how surgeons perform operations has educational implications related to learning curves and patient safety. We studied the effects of experience, training, and visual-spatial ability on 3D perception of 2D angiographic images of abdominal aortic aneurysms (AAA).
A novel computer-based method was developed to produce 3D depth maps based on subjects' interpretations of 2D images. Seven experts (certified vascular surgeons) and 20 novices (medical or surgical trainees) were presented with a 2D AAA angiographic image. With software specifically designed for this study, a depth map representing each subject's 3D interpretation of the 2D angiogram was produced. The novices were then randomized into a control group and a treatment group, who received a 5-minute AAA anatomy educational session. All subjects repeated the exercise on a second AAA image. Finally, all novices were given tests of visual-spatial ability, including the Surface Development Test and the Mental Rotations Test. Comparisons between experts and novices were made with depth map comparison, a subject's perception of overall object contour.
The depth maps were significantly different (depth map comparison, P