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).