title: Hepatocellular lesions with increased iron uptake on superparamagnetic iron oxide-enhanced magnetic resonance imaging in cirrhosis or chronic hepatitis: comparison of four magnetic resonance sequences for lesion conspicuity.
abstract: OBJECTIVE
  The aim of this study was to determine the adequate MR sequence for the lesion conspicuity of hepatocellular lesions with increased iron uptake on superparamagnetic iron oxide (SPIO)-enhanced MRI.
  
  
  METHODS
  SPIO-enhanced MRI was performed using a 1.5-T system. Among 25 patients with hypovascular hepatocellular nodules on contrast-enhanced dynamic CT (no early enhancement at arterial phase and hypoattenuation at equilibrium phase), 39 lesions with increased iron uptake on SPIO-enhanced MRI were evaluated. SPIO-enhanced MRI included (1) T1-weighted in-phase gradient recalled echo (GRE) images, (2) T2-weighted fast spin echo (FSE) images, (3) T2*-weighted GRE with moderate TE (7 ms) and (4) long TE (12 ms). The lesion-to-liver contrast-to-noise ratios of the hepatocellular nodule and the signal-to-noise ratio (SNR) of the hepatic parenchyma were calculated by one radiologist for a quantitative assessment. MR images were reviewed retrospectively by two independent radiologists to compare the subjective lesion conspicuity in each image set based on a four-point rating scale.
  
  
  RESULTS
  The mean lesion-to-liver contrast-to-noise ratios with T2*-weighted GRE with moderate TE (7 ms) was highest (5.79+/-3.71) and was significantly higher than those with T1-weighted, in-phase images (3.79+/-3.23, P<.01), T2-weighted images (2.72+/-1.52, P<.001) and T2*-weighted GRE with long TE (12 ms) (3.93+/-2.69, P<.05). The subjective rating of lesion conspicuity was best on the T2*-weighted GRE with moderate TE (7 ms), followed by that on the T2*-weighted GRE with moderate TE (7 ms; P<.05).
  
  
  CONCLUSIONS
  T2*-weighted GRE sequence with moderate TE (7 ms) showed high lesion-to-liver contrast-to-noise ratios in hepatocellular lesions with increased iron uptake on SPIO-enhanced MRI, indicating better lesion conspicuity of hypointense hepatocellular nodules in cirrhosis or chronic hepatitis.
authors.affiliation: Department of Radiology, Yamaguchi University Graduate School of Medicine, Yamaguchi 755-8505, Japan. masa-ygc@umin.ac.jp
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tanabe
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Ito
authors.forename: Ayame
authors.initials: A
authors.lastname: Shimizu
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fujita
authors.forename: Hideko
authors.initials: H
authors.lastname: Onoda
authors.forename: Shigenari
authors.initials: S
authors.lastname: Yamatogi
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Washida
authors.forename: Naofumi
authors.initials: N
authors.lastname: Matsunaga
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000378:metabolism; D002908:Chronic Disease; D003287:Contrast Media / Q000493:pharmacokinetics; D003911:Dextrans; D005260:Female; D052203:Ferrosoferric Oxide; D006505:Hepatitis / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007501:Iron / Q000493:pharmacokinetics; D008103:Liver Cirrhosis / Q000175:diagnosis* / Q000378:metabolism; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D058185:Magnetite Nanoparticles; D008297:Male; D008875:Middle Aged; D010087:Oxides / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; C097921:ferumoxtran-10; D007501:Iron; D052203:Ferrosoferric Oxide