In the treatment of adult brain tumors, radiation therapy is associated with long-term effects including vascular injury in the form of cerebral microbleeds (CMBs), and white-matter changes. Ultra high-field MRI was used to detect CMBs, and predictors of CMB development were identified. Changes in individual and total CMB burden were characterized from serial imaging data with white-matter changes. Time since RT, multiple surgeries, tumor type and location were all predictors of development. The total number and volume of CMBs increased over time, while individual CMB size decreased and the surrounding white-matter showed signs of degradation.