women with histologically confirmed breast cancer (by core needle biopsy)

women with >= 2 cm clinically or radiologically measureable breast cancer

women scheduled to receive neoadjuvant chemotherapy as part of their treatment plan

women competent to sign study specific written informed consent

women willing to comply with protocol requirements

women who are pregnant

women who have undergone open surgical (excisional) biopsy for breast cancer diagnosis

women who have had a prior history of breast cancer in the same breast

women with known cardiac shunt, pulmonary hypertension or hypersensitivity to perflutren agent

women who cannot consent for themselves