Final answer:
The lateral decubitus position is helpful during an ultrasound to mimic a mass found on a CC view of mammography or MRI.
Step-by-step explanation:
During an ultrasound, a patient position that can mimic a mass found on a CC view of mammography or MRI is the lateral decubitus position. In this position, the patient lies on their side with the arm on the same side as the breast being examined raised above the head. This helps to compress the breast tissue and create a similar appearance to a mass on other imaging modalities.