This case illustrates how important it is to correlate the mammogram findings with ultrasound findings in 3 dimensions, keeping in mind the mammogram views are not at right angles to each other. You cannot simply assume that the ultrasound lesion you are presented with is in fact the lesion seen on the mammogram. 

If you have both mammogram and ultrasound images use the opportunity to decide on the mammogram on which radian the lesion is and make sure it correlates with the ultrasound position. In this specific case the initial reader thought the lesion was at 3 o'clock which is clearly not possible if you look at the mammogram.