There are 2 groups or cohorts in this study. The cohort patient's are in is based on their clinical treatment plan set by your physician. The number of imaging visits and timing of visits will be determined by what cohort they are in.

If the patient is in cohort #1, they will make 4 visits to UAB. They will be scheduled for a pre-study or screening visit. During the pre-study visit, once consented, they will have a blood draw to determine kidney function, and a pregnancy test if they are a woman of childbearing potential. Their vital signs will be taken, they will be asked to fill out an MRI questionnaire, and they will have a PET/MRI fit test. If eligible for the study, they will be scheduled for the first PET imaging visit which will occur before they start chemotherapy. During this PET imaging visit, they will have a pregnancy test if they are a woman of childbearing potential. A plastic catheter will be placed into a vein in their arm and they will then be positioned in the PET/MRI scanner. Once positioned, they will be injected with the investigational radioactive drug, \[18F\]FMISO. They will then be imaged for up to 90 minutes during which time they will receive an FDA approved contrast agent called Prohance (gadoteridol). Once all the procedures are complete, the catheter will be removed and they may resume all normal activities. The patient will receive a follow-up phone call within 24-48 hours of your injection to be sure they are not experiencing any adverse events. Their second imaging visit will be scheduled after they receive therapy with Herceptin alone and within 10 days before their first cycle of combination therapy including Herceptin. During the second PET imaging visit, the same procedures will be followed as were performed during your first PET imaging visit. They will receive a follow-up phone call within 24-48 hours of your injection to be sure you are not experiencing any adverse events. Their third PET imaging visit will be scheduled after their first cycle of combination therapy including Herceptin and within 10 days before starting their second cycle of combination therapy including Herceptin. During the third PET imaging visit, the same procedures will be followed as were performed during their first and second PET imaging visits. The patient will receive a follow-up phone call within 24-48 hours of their injection to be sure they are not experiencing any adverse events.

If the patients are in cohort #2, they will make 3 visits to UAB. The patients will be scheduled for a pre-study or screening visit. During the pre-study visit, once consented, they will have a blood draw to determine kidney function, and a pregnancy test if they are a woman of childbearing potential. Their vital signs will be taken, they will be asked to fill out an MRI questionnaire, and they will have a PET/MRI fit test. If eligible for the study, they will be scheduled for the first PET imaging visit which will occur before they start chemotherapy. During this visit, they will have a pregnancy test if they are a woman of childbearing potential. A plastic catheter will be placed into a vein in their arm and they will then be positioned in the PET/MRI scanner. Once positioned, the patient will be injected with the investigational radioactive drug, \[18F\]FMISO. They will then be imaged for up to 90 minutes during which time they will receive an FDA approved contrast agent called Prohance (gadoteridol). Once all the procedures are complete, the catheter will be removed and the patient may resume all normal activities. They will receive a follow-up phone call within 24-48 hours of your injection to be sure they are not experiencing any adverse events. Your second PET imaging visit will be scheduled after your first cycle of combination therapy including Herceptin and within 10 days before starting the second cycle of combination therapy including Herceptin. During the third PET imaging visit, the same procedures will be followed as were performed during the first PET imaging visits. The patient will receive a follow-up phone call within 24-48 hours of your injection to be sure they are not experiencing any adverse events.

We will follow the patients every 6 months for 5 years by reviewing their medical records to see how they are doing.