Impact of Image Orientation During Transvaginal Ultrasound on Learning: A Randomized Trial

Background

Ultrasonography is considered safe but highly operator dependent. Ultrasonography is being used increasingly in gynecology and obstetrics; however the training of novices in transvaginal ultrasound is performed differently with respect to the orientation of the ultrasound image, which often differs between operators and institutions. The image may be oriented top- down (transducer at the top) or bottom-up (transducer at the bottom). The different orientations of the image are a challenge for novices when being supervised by senior clinicians with different preferences for image orientation. As for now, there is no international consensus on image orientation and there is no evidence to support the superiority of one over the other in terms of learning curves and educational outcomes such as skills transfer. Transvaginal ultrasound is, like all other kinds of ultrasound, associated with long learning curves and is therefore time-consuming and requires extensive training. Transvaginal ultrasound is often associated with some discomfort to the patient, which can be reduced with adequate initial training. It therefore seems reasonable to determine how to provide the most effective initial transvaginal ultrasound training to reduce unnecessary patient discomfort and improve diagnostic accuracy through accelerated learning curves.

A recent study involving laparoscopic training, suggests that novices learn best from simplified practice during initial skills acquisition because it allows them to deal with future task complexity better than when being faced with complex image orientation. These findings are consistent with cognitive load theory, which emphasizes the limitations of the working memory when learning new tasks. Optimal learning occurs when the cognitive load of a new task is within the limits of the learner's working memory and when instructional features that do not contribute to learning are eliminated. Basic knobology (operating the ultrasound machine controls) and image interpretation represent significant sources of cognitive load for ultrasound novices and the acquisition of images should therefore be as simple as possible to avoid exceeding the working memory of the learner.

When looking at an ultrasound image, the operator transforms the two-dimensional ultrasound image into a three-dimensional internal representation of the structure being examined. Alignment of the image according to the physical angle of the transvaginal ultrasound probe by having the image facing bottom-up is by some clinicians perceived as the most intuitive anatomical orientation. Other clinicians prefer having the ultrasound image oriented the same way (top-down) regardless of the type of examination being performed (transabdominal or transvaginal).

The research question in this study is: