Neuroimaging is the use of various non/invasive techniques to evaluate the structural and functional properties of the central nervous system (CNS) in healthy individuals and patients [1]. MRI has become an effective non-invasive technique of structural imaging, used in the diagnosis and classification of brain tumors and the evaluation of treatment response [2-4].

Contrast agents (CAs) which can be used to increase the contrast of brain structure in MRN may be categorized by their magnetic and chemical properties, administration method, effect on MR image and application. Orally or intravenously administered MRI-CAs can be used as extracellular fluid agents, blood pool agents and targeted/organ-specific agents [5]. Iron oxide magnetite particles which can be categorized according to their mean hydrodynamic particle size as superparamagnetic iron oxide (SPIO) and ultra-small SPIO (USPIO) [6]. FDA approved Ferumoxytol, USPIO nanoparticle with a 30 nm hydrodynamic diameter with a circulating half-life of about 14 hours in humans is used against iron deficiency anemia [7-8]. At doses up to 400 mg Fe/kg in rodents, ferumoxytol is non-lethal. Despite a potential risk of a lethal allergic response, Ferumoxytol is generally well tolerated by most patients with rare anaphylactic iron-induced hypotensive reaction [7-8]. The modified carbohydrate coating of ferumoxytol permits monitoring defects and tumors in the blood brain barrier using dynamic MRI studies [9] such as perfusion imaging and MR angiography or enhancing details using time delayed MRI [10]. Administered as a short IV bolus, Ferumoxytol acts as a true blood pool agent, providing advantages in relative cerebral blood volume (rCBV) measurement [11].