Expert visual guidance of ultrasound for telemedicine

Expert visual guidance (EVG) is computer assistance that displays to the examiner how the image plane moves towards (or away from) a desired anatomical location as the ultrasound probe is manipulated over the patient's body. We tested whether EVG by a remote expert could assist inexperienced examiners in acquiring abdominal ultrasound images. The inexperienced examiners were 20 medical students, who were randomly assigned to verbal instruction alone (Group 1) or to EVG (Group 2). The examiners were tested on their ability to visualize the abdominal aorta and the right kidney. Group 2 was more successful in identifying specified anatomy in longitudinal and cross-sectional views of the aorta (95 vs. 75%, P = 0.032) and kidney (98 vs. 88%, P = 0.09). The groups succeeded equally well in obtaining a true cross-sectional view of the aorta. Kidney length was also similar when measured by the two groups. The results demonstrate that an inexperienced ultrasonographer can be significantly assisted by EVG compared to verbal instruction alone. This could be useful for tele-mentoring in rural hospitals as well as for teaching, both in person and at a remote site.