title: First-pass contrast-enhanced magnetic resonance angiography in humans using ferumoxytol, a novel ultrasmall superparamagnetic iron oxide (USPIO)-based blood pool agent.
abstract: OBJECTIVE
  To evaluate the feasibility of first-pass contrast-enhanced magnetic resonance angiography (MRA) using ferumoxytol in humans.
  
  
  METHODS
  First-pass and equilibrium phase MRA were performed using ferumoxytol in one healthy volunteer and 11 patients with a fast three-dimensional spoiled gradient recalled (SPGR) pulse sequence. The examined vessels included carotid arteries, thoracic aorta, abdominal aorta, and peripheral arteries. A dose of either 71.6 micromol Fe/kg (n = 9), or 35.8 micromol Fe/kg (n = 3) was used. Based on a phantom study, the agent with initial concentration of 537.2 micromol Fe/mL was diluted by either four-fold (134.3 micromol Fe/mL) or eight-fold (67.1 micromol Fe/mL) for first-pass MRA.
  
  
  RESULTS
  All subjects completed their studies without adverse events. First-pass MRA showed selective arterial enhancement, with both arterial and venous enhancement on delayed acquisitions. Selective venous enhancement could be obtained by subtraction of arterial phase images from equilibrium phase images. The findings in ferumoxytol MRA were consistent with the results of original vascular tests.
  
  
  CONCLUSIONS
  Our preliminary experience supports the feasibility of first-pass MRA with ferumoxytol. Satisfactory arterial enhancement during first-pass imaging is obtained with injection of diluted contrast agent. With ferumoxytol, arteries and veins can be selectively depicted in a single exam.
authors.affiliation: Department of Radiology, Evanston Northwestern Healthcare and Northwestern University's Feinberg School of Medicine, Evanston, Illinois, USA. lwei@enh.org
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Sean
authors.initials: S
authors.lastname: Tutton
authors.forename: Anthony T
authors.initials: AT
authors.lastname: Vu
authors.forename: Linda
authors.initials: L
authors.lastname: Pierchala
authors.forename: Belinda S Y
authors.initials: BS
authors.lastname: Li
authors.forename: Jerome M
authors.initials: JM
authors.lastname: Lewis
authors.forename: Pottumarthi V
authors.initials: PV
authors.lastname: Prasad
authors.forename: Robert R
authors.initials: RR
authors.lastname: Edelman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D052203:Ferrosoferric Oxide; D006801:Humans; D007501:Iron; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010087:Oxides; D019047:Phantoms, Imaging
chemical_list: D003287:Contrast Media; D010087:Oxides; D007501:Iron; D052203:Ferrosoferric Oxide