This is a pilot study in patients with known or suspected primary or metastatic breast cancer with one lesion that is 1.5 cm in diameter or greater may be eligible for this study. Patients may participate in this study if they are at least 18 years of age. Up to 30 evaluable subjects will participate in a single imaging cohort. Patients will be stratified by breast cancer subtype with prioritization to recruit at least 10 estrogen-receptor-expressing (ER+) and 10 triple-negative breast cancers (TNBC).Patients who come to the University of Pennsylvania for diagnosis and/or treatment of breast cancer and who meet the study inclusion criteria may be approached by study personnel for recruitment into this study. Patients will be approached about study participation regardless of race or ethnic background. We anticipate enrolling up to 30 evaluable participants.

You may be eligible for this study if you meet the following criteria:

• Conditions: breast cancer
• Age: 99 years or below
• Gender: All