Vacuum-assisted biopsies are done using Suros technologies with the assistance of a mammogram, MRI or ultrasound. A small cut is made in the skin after it has been numbed. A hollow probe is entered through the cut and a piece (or several pieces) of tissue are removed. Vacuum-assisted biopsies generally remove more tissue than core needle biopsies. The medical term for this type of biopsy is a stereotactic biopsy.