New marker devices have been developed that are sonographically visible. They consist of the standard mammographically visible metallic clip surrounded by a sonographically visible collagen plug. It is hypothesized that radiologists and surgeons can effectively localize the clip with intra-operative ultrasound and then resect the lesion. If so, the pre-operative wire localization procedure could be eliminated. This could improve the patient experience while saving time and money by reducing the number of invasive procedures from 3 (biopsy, wire-localization and operation) to 2 (biopsy and operation).