Florbetapir F 18 is an experimental radioactive drug that may allow doctors to image changes in the brain using a PET (Positron Emission Tomography) scanner. The purpose of this study is to evaluate the imaging characteristics of, Florbetapir F 18 (also known as 18F-AV-45) in patients who have previously undergone bleeding in their brains. Florbetapir F 18 binds to amyloid-ß peptide (Aß) that accumulates in the brains of patients with bleeding. These accumulations are called amyloid plaques and when extensive are labeled cerebral amyloid angiopathy (CAA). Florbetapir F 18 sticks to the amyloid plaques in the brain and emits a low level of gamma rays which can be detected by a PET camera.

MRI detected microbleeds have been identified as markers of clinically silent hemorrhage from bleeding-prone vessels. Another imaging marker of vessel damage and risk of bleeding is the spot sign (SS). Finally, certain genetic signatures (ApoE genotype) have been shown to be associated with Aß deposition in the brain or predispose patients to higher risks of bleeding. This research study will explore the interactions of these factors and understand the physiology of intracerebral bleeding.

Inclusion Criteria:

• Prior intracranial hemorrhage at least 3 months prior
• Patients >18 years

Exclusion Criteria:

1. Modified Rankin score >3.
2. Clinically significant medical comorbidities which in the opinion of the investigator might pose a potential safety risk to the subject.
3. Women of childbearing potential who are not surgically sterile, not refraining from sexual activity or not using reliable methods of contraception.
4. Have a history of relevant severe drug allergy or hypersensitivity
5. Patients who withdraw consent. Age and gender-matched microbleed patients previously demonstrating MRI microbleeds without prior macrobleeds will be recruited from stroke clinic

Macrobleed patients will be selected from a prospectively maintained ICH database at Sunnybrook Hospital.