 Part 1 is a two-period, crossover, dose-finding study, which will be performed in 12 healthy female volunteers to determine the optimal dose as well as the safety and tolerability of the tissue-specific, contrast agent Sonazoid GE Healthcare, Oslo, Norway for human lymphatic applications. In Part 2 lymphosonographic SLN identification will be compared to that of isotope mapping during surgery on 90 female, breast cancer patients. 