title: Comparative analysis of ferumoxytol and gadoteridol enhancement using T1- and T2-weighted MRI in neuroimaging.
abstract: OBJECTIVE
  Ferumoxytol, an ultrasmall superparamagnetic iron oxide particle, has been suggested as a potential alternative MRI contrast agent in patients with renal failure. We compared ferumoxytol to gadoteridol enhancement on T1- and T2-weighted MRI in CNS disorders to explore its diagnostic utility.
  
  
  METHODS
  Data were collected from three protocols in 70 adults who underwent alternate-day gadoteridol- and ferumoxytol-enhanced MRI using identical parameters. Two neuroradiologists measured lesion-enhancing size and intensity on contrast-enhanced T1-weighted images in consensus. T2-weighted images were evaluated for the presence of contrast-enhanced hypointensity. Mixed model repeated measures analysis of variance determined differences between T1-weighted enhancement size and intensity for individual protocols and group.
  
  
  RESULTS
  After exclusions, 49 MRI studies in 29 men and 20 women (mean age, 51 years) were assessed. T1-weighted estimated enhancing sizes were different between agents (p = 0.0456) as a group; however, no differences were observed with untreated gliomas (n = 17) in two protocols (p = 1.0 and p = 0.99, respectively). Differences in T1-weighted enhancement intensity between agents were significant for the group overall (p = 0.0006); however, three-way interactions were not significant (p = 0.1233). T2-weighted images were assessed for contrast-enhanced hypointensity, observed in 26 of 49 (53%) ferumoxytol and zero of 49 (0%) gadoteridol scans.
  
  
  CONCLUSIONS
  Ferumoxytol may be a useful MRI contrast agent in patients who are unable to receive gadolinium-based contrast agents. Greater experience with a wider variety of disorders is necessary to understand differences in enhancement with ferumoxytol compared with gadolinium-based contrast agents, given their different mechanisms of action.
authors.affiliation: Department of Radiology, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd, Mail Code CR 135, Portland, OR 97239, USA. hamiltob@ohsu.edu
authors.forename: Bronwyn E
authors.initials: BE
authors.lastname: Hamilton
authors.forename: Gary M
authors.initials: GM
authors.lastname: Nesbit
authors.forename: Edit
authors.initials: E
authors.lastname: Dosa
authors.forename: Seymur
authors.initials: S
authors.lastname: Gahramanov
authors.forename: Bill
authors.initials: B
authors.lastname: Rooney
authors.forename: Eric G
authors.initials: EG
authors.lastname: Nesbit
authors.forename: Joshua
authors.initials: J
authors.lastname: Raines
authors.forename: Edward A
authors.initials: EA
authors.lastname: Neuwelt
mesh_terms: D000704:Analysis of Variance; D001932:Brain Neoplasms / Q000175:diagnosis*; D003287:Contrast Media; D005260:Female; D052203:Ferrosoferric Oxide; D005682:Gadolinium; D006571:Heterocyclic Compounds; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted; D016018:Least-Squares Analysis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds
chemical_list: D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C062402:gadoteridol; D005682:Gadolinium; D052203:Ferrosoferric Oxide