 In Part 2 lymphosonography will compare SLN identification to that of isotope mapping during surgery on 90 female, breast cancer patients. A state-of-the-art S3000 scanner with contrast-specific imaging capabilities will be used to localize lymphatic drainage from breast cancers after subdermal administration of Sonazoid. The number and locations of the SLNs identified by the two imaging modalities CEUS and isotope mapping will be compared with dye-guided surgery as the reference standard for SLN detection. Moreover, as each SLN is resected it will be assessed ex vivo for the presence of radioactivity using a gamma probe, Sonazoid using CEUS and blue dye via visual inspection by the surgeon. All SLNs that are surgically removed will be documented and sent for histopathologic evaluation. 