Image-guided biopsy is performed when the abnormal area in the breast is too small to be felt, making it difficult to locate the lesion by hand (called palpation). In stereotactic breast biopsy, a special mammography machine uses ionizing radiation to help guide the radiologist’s instruments to the site of the abnormal growth. A stereotactic breast biopsy is performed to remove some cells through a less-invasive procedure involving a hollow needle from a suspicious area in the breast and examine them under a microscope to determine a diagnosis.