Ferumoxytol- and Gadolinium-Labeled MRI in Measuring Tumors Before or After Treatment in Patients With Primary or Metastatic Brain Tumors

PRIMARY OBJECTIVES: I. To compare quantitative blood brain barrier permeability measurements (derived transfer coefficient \[Ktrans\]) of a standard gadolinium (Gd) MRI contrast agent at 3T and 7T using dynamic contrast enhancement (DCE) MRI. II. To compare dynamic susceptibility contrast (DSC) based perfusion measures at 3T and 7T. SECONDARY OBJECTIVES: I. To describe the blood brain barrier permeability to ferumoxytol (ferumoxytol non-stoichiometric magnetite) and to a standard gadolinium-based MRI contrast agent using signal intensity changes as described above. II. To describe cerebral blood volume (CBV) measurements obtained using a standard gadolinium MRI contrast agent and ferumoxytol. III. To evaluate tumor microvascularity on susceptibility-weighted images (SWI). IV. To describe the microscopic distribution of ferumoxytol particles in tissue removed from subjects undergoing surgery. OUTLINE: Patients are assigned to 3T or 7T magnet within the subgroups. Patients receive gadolinium intravenously (IV) on day 1 and ferumoxytol non-stoichiometric magnetite IV on day 2. Patients undergo anatomical MRI sequences with 3T or 7T at baseline and on days 1-3. Patients also undergo DSC MRI and DCE MRI on days 1-2. Day 1 and day 2 imaging sessions may be separated by up to 7 days. After completion of study, patients are followed up at approximately 4-6 weeks.