Breast wire localization is done before a surgical biopsy. Using either ultrasound or mammography the radiologist locates the abnormality. Local anesthetic is then used to numb the site before the radiologist inserts a hollow needle into the middle of the abnormality. Through this needle the radiologist then slides a small wire with a “clip” on the end which is deposited in the abnormal tissue. This is then removed by the surgeon during the surgical biopsy procedure.