title: Contrast-enhanced functional blood volume imaging (CE-fBVI): enhanced sensitivity for brain activation in humans using the ultrasmall superparamagnetic iron oxide agent ferumoxytol.
abstract: Functional MRI (fMRI) brain studies performed in the presence of a steady-state or "blood pool" contrast agent yields activation maps that are weighted for cerebral blood volume (CBV). Previous animal experiments suggest significant contrast-to-noise ratio (CNR) improvements, but these studies have not yet been performed in humans due to the lack of availability of a suitable agent. Here we report the use of the USPIO ferumoxytol (AMAG Pharmaceuticals, Inc., Cambridge, MA) for functional brain activation in humans, termed contrast enhanced functional blood volume imaging (CE-fBVI). Four subjects were scanned during a unilateral finger tapping task with standard blood-oxygen level dependent (BOLD) imaging before contrast and CE-fBVI after contrast injection. The CE-fBVI response showed both a fast (5.8±1.3 s) and a slow (75.3±27.5 s) component of CBV response to stimuli. A significant CNR gain of approximately 2-3 was found for CE-fBVI compared to BOLD fMRI. Interestingly, less susceptibility-related signal dropouts were observed in the inferior frontal and temporal lobes with CE-fBVI. The combination of higher CNR and better spatial specificity, enabled by CE-fBVI using blood pool USPIO contrast agent opens the door to higher resolution brain mapping.
authors.affiliation: Department of Radiology, Stanford University, CA, USA. qiudeqiang@gmail.com
authors.forename: Deqiang
authors.initials: D
authors.lastname: Qiu
authors.forename: Greg
authors.initials: G
authors.lastname: Zaharchuk
authors.forename: Thomas
authors.initials: T
authors.lastname: Christen
authors.forename: Wendy W
authors.initials: WW
authors.lastname: Ni
authors.forename: Michael E
authors.initials: ME
authors.lastname: Moseley
mesh_terms: D000328:Adult; D001810:Blood Volume / Q000502:physiology; D001811:Blood Volume Determination / Q000379:methods*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D003287:Contrast Media; D052203:Ferrosoferric Oxide; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance / Q000502:physiology; D059629:Signal-To-Noise Ratio; D055815:Young Adult
chemical_list: D003287:Contrast Media; D052203:Ferrosoferric Oxide