title: Abdominal vessel enhancement with an ultrasmall, superparamagnetic iron oxide blood pool agent: evaluation of dose and echo time dependence at different field strengths.
abstract: OBJECTIVE
  The purpose of the study was to determine the dose and echo time dependence of abdominal vessel enhancement at magnetic resonance (MR) imaging after injection of a blood pool contrast agent at two field strengths.
  
  
  METHODS
  Sixteen healthy volunteers received NC100150 Injection at three dose levels (1.0 mg, 2.5 mg, and 4.0 mg of iron per kilogram of body weight). Images of the aorta and inferior vena cava (IVC) were obtained at 0.5 or 1.5 T. Four sequences with varying echo times were used with each subject. Signal intensities were recorded from the aorta, IVC, vessel vicinity, air, and a marker outside the patient. Contrast-to-noise ratios (CNRs) were calculated for the vessels. Aortic delineation was subjectively evaluated.
  
  
  RESULTS
  Images with the highest mean vessel signal intensities, subjectively assessed as satisfactory for aortic delineation, were obtained with 2.5-4.0 mg of iron per kilogram of body weight at both field strengths. The highest CNR was found with 4.0 mg of iron per kilogram of body weight at 1.5 T. An increase in echo time caused larger signal intensity loss at larger dose levels. The signal intensity from the IVC was higher than that of the aorta at all dose levels, echo times, and field strengths.
  
  
  CONCLUSIONS
  NC100150 Injection is an efficient T1-reducing agent at both 0.5 and 1.5 T. A positive dose response for CNR of the aorta and IVC was seen at 1.5 T.
authors.affiliation: Department of Diagnostic Radiology, Uppsala University Hospital, Sweden.
authors.forename: L J
authors.initials: LJ
authors.lastname: Wikström
authors.forename: L O
authors.initials: LO
authors.lastname: Johansson
authors.forename: B A
authors.initials: BA
authors.lastname: Ericsson
authors.forename: A
authors.initials: A
authors.lastname: Börseth
authors.forename: P A
authors.initials: PA
authors.lastname: Akeson
authors.forename: K H
authors.initials: KH
authors.lastname: Ahlström
mesh_terms: D000328:Adult; D001011:Aorta / Q000033:anatomy & histology*; D003287:Contrast Media / Q000008:administration & dosage*; D003911:Dextrans; D004305:Dose-Response Relationship, Drug; D052203:Ferrosoferric Oxide; D006801:Humans; D007501:Iron / Q000008:administration & dosage*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D008297:Male; D010087:Oxides / Q000008:administration & dosage*; D014682:Vena Cava, Inferior / Q000033:anatomy & histology*
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; C097921:ferumoxtran-10; D007501:Iron; D052203:Ferrosoferric Oxide