Contrast-Enhanced Ultrasound Scan for the Estimation of Tissue Pressure in Patients With Breast Cancer

Inclusion Criteria: * Provide signed and dated informed consent form * Be conscious, willing and able to comply with all study procedures and be available for the duration of the study * At least 21 years old * Be scheduled for a breast biopsy (Breast Imaging Reporting and Data System \[BIRAD\] 4, 4A, 4B, 4C or 5) * Patient with an at least 1 cm mass located at \< 3 cm depth, approachable by 2.5 inch needle * Be medically stable as determined by the investigator * If a female of child-bearing potential, must have a negative urine pregnancy test within 24 hours prior to administration of Definity Exclusion Criteria: * Females who are pregnant or nursing * Patients who are medically unstable, patients who are seriously or terminally ill, and patients whose clinical course is unpredictable. For example: * Patients on life support or in a critical care unit * Patients with unstable occlusive disease (e.g., crescendo angina) * Patients with clinically unstable cardiac arrhythmias, such as recurrent ventricular tachycardia * Patients with uncontrolled congestive heart failure (New York Heart Association \[NYHA\] class IV) * Patients with recent cerebral hemorrhage * Patients who have undergone surgery within 24 hours prior to the study sonographic examination * Patients with known hypersensitivity or allergy to any component of Definity * Patients with unstable cardiopulmonary conditions or respiratory distress syndrome * Patients with uncontrollable emphysema, pulmonary vasculitis, pulmonary hypertension or a history of pulmonary emboli