Hi,
If your Radiologist feels anything suspicious in your breast, or sees something suspicious on an imaging study, he or she will recommend a biopsy.
The surgeon or radiologist uses imaging studies to guide the needle to the right location. When Ultrasound is used it’s called “ultrasound-guided biopsy” and “Stereotactic Needle Biopsy” is used when a special mammography machine uses x-rays to help guide the radiologist's biopsy equipment to the site of the abnormal growth.
I hope this helps and I wish you benign results.