title: Detection of hepatocellular carcinoma and its metastases with various pulse sequences using superparamagnetic iron oxide (SHU-555-A).
abstract: BACKGROUND
  To identify the most useful combinations of various pre- and postcontrast magnetic resonance (MR) image sequences in detecting hepatocellular carcinoma (HCC) and its intrahepatic metastases before and after injection of SHU-555-A.
  
  
  METHODS
  Thirty-eight lesions in 16 patients were evaluated before and after administration of SHU-555-A by using fast spin echo (FSE), gradient echo (GRE), and echo planar (EP) imaging sequences using a 1.5-Tesla superconducting MR system. The signal intensity ratio (SIR) and contrast-to-noise ratio (CNR) of the lesions, signal-to-noise ratios, and other parameters were calculated.
  
  
  RESULTS
  Tumors were better detected after injection of SHU-555-A on all pulse sequences except on out-of-phase T1-weighted (T1W)-GRE sequences. Tumor detectability was higher for precontrast EP imaging and T2*-weighted (T2*W)-GRE sequences, whereas detectability at postcontrast was higher for T2*W-GRE, proton-density-weighted-FSE, and in-phase T1W-GRE sequences. The SIR and CNR at precontrast were highest for EP imaging, and those at postcontrast were highest for T2*W-GRE.
  
  
  CONCLUSIONS
  SHU-555-A will increase the detectability of HCC and its liver metastases. T1W- and T2*W-GRE sequences would be the sequences of choice.
authors.affiliation: Department of Radiology, Yamanashi Medical University, Tamaho, Nakakoma, Yamanashi, 409-38, Japan.
authors.forename: A S
authors.initials: AS
authors.lastname: Arbab
authors.forename: T
authors.initials: T
authors.lastname: Ichikawa
authors.forename: T
authors.initials: T
authors.lastname: Araki
authors.forename: K
authors.initials: K
authors.lastname: Toyama
authors.forename: A
authors.initials: A
authors.lastname: Nambu
authors.forename: S
authors.initials: S
authors.lastname: Ohsawa
authors.forename: H
authors.initials: H
authors.lastname: Kumagai
authors.forename: Y
authors.initials: Y
authors.lastname: Aikawa
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000556:secondary*; D003287:Contrast Media; D003911:Dextrans; D017352:Echo-Planar Imaging; D052203:Ferrosoferric Oxide; D006801:Humans; D007501:Iron; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods; D058185:Magnetite Nanoparticles; D010087:Oxides
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; D007501:Iron; C065507:ferumoxides; D052203:Ferrosoferric Oxide