title: New intravascular contrast agent applied to dynamic contrast enhanced MR imaging of human breast cancer.
abstract: OBJECTIVE
  To evaluate the feasibility of using dynamic contrast-enhanced MR imaging with a new intravascular contrast agent in grading human breast cancer.
  
  
  METHODS
  23 patients with 27 breast tumors (21 carcinomas and 6 fibroadenomas) were examined with dynamic MR imaging after administration of Clariscan, an iron oxide nanoparticle with large T1 relaxivity and a long plasma half life. A 3D T1-weighted gradient echo sequence with an acquisition time of 60 s was repeated at regular intervals of 3-5 min before and up to 1 h after injection of 2 mg/kg b.w. of Clariscan. The endothelial transfer constant, Kps, which reflects overall vascular permeability, and the fractional plasma volume, fPV, were estimated from time-intensity curves acquired from three separate regions of interest (ROIs): whole tumor, a permeability hot spot, and a blood volume hot spot. Kps and fPV were compared to the results of histologic tumor grading (Scarff-Bloom-Richardson, SBR) and microvascular density, MVD.
  
  
  RESULTS
  A statistically significant correlation between the MR-derived Kps parameters and the SBR score was obtained for the whole tumor ROI (R = 0.70), and for the permeability hot spot ROIs (R = 0.67). A correlation between fPV and SBR was detected for the blood volume hot spot ROIs (R = 0.48). There was no statistically significant correlation between Kps or fPV with MVD.
  
  
  CONCLUSIONS
  The results support the hypothesis that dynamic MR with the intravascular contrast agent Clariscan may be used for non-invasive tumor grading.
authors.affiliation: MR-Center, St. Olav's Hospital HF, Trondheim, Norway. JanaR@mr.ntnu.no
authors.forename: J
authors.initials: J
authors.lastname: Rydland
authors.forename: A
authors.initials: A
authors.lastname: BjØrnerud
authors.forename: O
authors.initials: O
authors.lastname: Haugen
authors.forename: G
authors.initials: G
authors.lastname: Torheim
authors.forename: C
authors.initials: C
authors.lastname: Torres
authors.forename: K A
authors.initials: KA
authors.lastname: Kvistad
authors.forename: O
authors.initials: O
authors.lastname: Haraldseth
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis*; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis; D003287:Contrast Media / Q000008:administration & dosage; D003911:Dextrans; D005240:Feasibility Studies; D005260:Female; D052203:Ferrosoferric Oxide; D018226:Fibroadenoma / Q000175:diagnosis; D006801:Humans; D007275:Injections, Intravenous; D007501:Iron / Q000008:administration & dosage; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles; D008875:Middle Aged; D010087:Oxides / Q000008:administration & dosage
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; C097921:ferumoxtran-10; D007501:Iron; D052203:Ferrosoferric Oxide