title: Optimal flip angle of Gd-EOB-DTPA-enhanced MRI in patients with hepatocellular carcinoma and liver metastasis.
abstract: OBJECTIVE
  To investigate optimal flip angle (FA) of three-dimensional fat-suppressed T1-weighted image on Gd-EOB-DTPA-enhanced MRI.
  
  
  METHODS
  Forty-five patients with 35 hepatocellular carcinomas (HCCs) and 16 liver metastases (METs) were investigated. Signal-to-noise ratio (SNR), tumor-to-liver contrast (TLC) of HCC and MET, visual image quality (IQ) and lesion conspicuity (LeCo) were evaluated at hepatobiliary phase with different FAs (FA15°-30°-45°-60° in 13 patients, FA5°-10°-15°-20°-25° in 32 patients).
  
  
  RESULTS
  TLC gradually showed better in range from FA15° to FA60° and FA5° to FA25°, but SNRs gradually decreased. SNR and TLC-MET at FA15° were significantly better than those at FA45° and FA60°. SNR at FA10° was significantly higher than at FA5°, FA20°, and FA25°. TLC-HCC and TLC-MET at FA5° were inferior to other FAs. IQs and LeCos at FA15° and FA30° were superior to those at FA45° and FA60°. IQs at FA5° and FA25° were significantly lower than those at FA10°-20°, although LeCos for HCC and MET at FA25° were superior to those at FA5°-20°.
  
  
  CONCLUSIONS
  FA ranging from 10° to 20° is suitable for hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI, to image HCC and MET.
authors.affiliation: Department of Radiology, Faculty of Medicine, Kinki University, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka, 589-8511, Japan, okada777@med.u-ryukyu.ac.jp.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Okada
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Wakayama
authors.forename: Norihisa
authors.initials: N
authors.lastname: Yada
authors.forename: Tomoko
authors.initials: T
authors.lastname: Hyodo
authors.forename: Kazushi
authors.initials: K
authors.lastname: Numata
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kagawa
authors.forename: Daisuke
authors.initials: D
authors.lastname: Nishiyama
authors.forename: Keizo
authors.initials: K
authors.lastname: Miyakoshi
authors.forename: Takamichi
authors.initials: T
authors.lastname: Murakami
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000473:pathology / Q000556:secondary; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000556:secondary; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA