Hypoxia Detected with Phase Contrast MRI Is an Early Event in Micrometastatic Breast Cancer Development in the Rat Brain

Matthew D. Budde¹, Eric Gold¹, E Kay Jordan¹, Melissa Smith-Brown¹, Joseph A. Frank¹

Hypoxia is an important prognostic factor in tumor growth and therapeutic response and is a driving force in the angiogenic cascade. Blood oxygen level dependent (BOLD) MRI contrast is related to the oxygenation status of tumors, but brain tumors can have significant edema that can complicate measurements of magnetic field inhomogeneities caused by deoxygenated hemoglobin. The purpose of this study was to determine if phase contrast MRI was more sensitive to vascular abnormalities than BOLD MRI in a rat model of breast cancer metastases to the brain and whether these changes were indicative of hypoxic changes that precede angiogenesis.