| Modified Boston criteria | |
| Definite CAA | Full postmortem examination demonstrating: |
| Lobar, cortical, or cortical-subcortical hemorrhage | |
| Severe CAA with vasculopathy | |
| Absence of other diagnostic lesion | |
| Probable CAA with supporting pathology | Clinical data and pathologic tissue (evacuated hematoma or cortical biopsy) demonstrating: |
| Lobar, cortical, or cortical-subcortical hemorrhage | |
| Some degree of CAA in specimen | |
| Absence of other diagnostic lesion | |
| Probable CAA | Clinical data and MRI or CT demonstrating: |
| Multiple hemorrhages restricted to lobar, cortical, or cortical-subcortical regions (cerebellar hemorrhage allowed), or Single lobar, cortical, or cortical-subcortical hemorrhage and focal* or disseminated¶ superficial siderosis | |
| Age ≥55 years | |
| Absence of other cause of hemorrhage or superficial siderosis | |
| Possible CAA | Clinical data and MRI or CT demonstrating: |
| Single lobar, cortical, or cortical-subcortical hemorrhage, or Focal* or disseminated¶ superficial siderosis | |
| Age ≥55 years | |
| Absence of other cause of hemorrhage or superficial siderosis |
