title: Detecting hepatocellular carcinoma in gadoxetic-acid-enhanced hepatobiliary-phase MR imaging at 3T: comparing high and low flip angle.
abstract: OBJECTIVE
  We evaluated the diagnostic performance of fat-suppressed 3D T1-weighted gradient-echo magnetic resonance imaging (MRI) sequences for the hepatobiliary phase of gadoxetic-acid-enhanced liver MRI between low and high flip angle (FA) at 3T.
  
  
  METHODS
  Forty-six patients with 62 HCCs were enrolled in this retrospective study from among 267 consecutive patients who underwent 3T MRI with low and high FA (10° and 25°) sequences at the hepatobiliary phase. A radiologist measured signal intensities and standard deviations (SD) of lesion, liver, and spleen and calculated signal-to-noise ratio, liver-spleen contrast, and liver-lesion contrast. Two reviewers assessed both image sequences using a five-point rating scale focusing on detecting hypointense lesions.
  
  
  RESULTS
  The high FA sequence showed significantly higher liver-spleen and liver-lesion contrast compared with those of low FA (p < 0.05, p < 0.05, respectively). Per-lesion sensitivities of high FA were higher than those of low FA (p < 0.05, p < 0.05, respectively), and per-person sensitivities were elevated on high FA (p < 0.05 in a reviewer). There were statistically significant differences for detecting HCCs larger than 1 cm (p < 0.05, p < 0.05, respectively).
  
  
  CONCLUSIONS
  Increasing FA in T1-weighted hepatobiliary-phase liver MRI may help in detecting HCC at 3T.
authors.affiliation: Department of Radiology, VHS Medical Center, 53, 61Gil, Jinhwangdoro, Gangdong-Gu, Seoul, 134-791, South Korea.
authors.forename: Mina
authors.initials: M
authors.lastname: Song
authors.forename: Hyeon Je
authors.initials: HJ
authors.lastname: Cho
authors.forename: Yun Ku
authors.initials: YK
authors.lastname: Cho
authors.forename: Mi Young
authors.initials: MY
authors.lastname: Kim
authors.forename: Sang Ik
authors.initials: SI
authors.lastname: Noh
authors.forename: Soo Hyun
authors.initials: SH
authors.lastname: Yang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis*; D003627:Data Interpretation, Statistical; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008099:Liver / Q000473:pathology*; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013154:Spleen / Q000473:pathology*
chemical_list: C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA