title: Validation of 10-Minute Delayed Hepatocyte Phase Imaging with 30° Flip Angle in Gadoxetic Acid-Enhanced MRI for the Detection of Liver Metastasis.
abstract: OBJECTIVE
  To compare 10-minute delayed hepatocyte phase imaging using a 30° flip angle (10 min-FA30) and 20-minute hepatocyte phase imaging using a 10° FA (20 min-FA10) in gadoxetic acid-enhanced MRI of patients with possible liver metastases, regarding lesion-to-liver contrast-to-noise ratio (CNR) and focal hepatic lesion (FHL) detection to evaluate whether 10 min-FA30 would be superior to 20 min-FA10.
  
  
  METHODS
  Eighty-three patients with 248 liver metastases and 78 benign FHLs who underwent gadoxetic acid-enhanced MRI with 10 min-FA30 and 20 min-FA10 were enrolled. Lesion-to-liver CNRs were compared between the two image groups. Two radiologists independently assessed the presence of FHLs using a four-point scale and detection sensitivity was calculated.
  
  
  RESULTS
  The mean CNR for liver metastases on the 10 min-FA30 (248.5 ± 101.6) were significantly higher than that of the 20 min-FA10 (187.4 ± 77.4) (p < 0.001). The mean CNR difference between the two image groups was 61.2 ± 56.8. There was no significant difference in detection sensitivity of FHLs for two readers between 10 min-FA30 (mean 97.7%) and 20 min-FA10 (mean 97.9%), irrespective of the lesion size or malignancy.
  
  
  CONCLUSIONS
  10 min-FA30 yielded higher CNR with similar sensitivity compared to 20 min-FA10. This finding indicates that 10 min-FA30 can potentially replace 20 min-FA10 with higher diagnostic performance and save 10 minutes of time.
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Korea.
authors.forename: Dahye
authors.initials: D
authors.lastname: Lee
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Korea.
authors.forename: Eun-Suk
authors.initials: ES
authors.lastname: Cho
authors.affiliation: Department of Radiology, CHA University, CHA Bundang Medical Center, Seongnam-si, Korea.
authors.forename: Dae Jung
authors.initials: DJ
authors.lastname: Kim
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Korea.
authors.forename: Joo Hee
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Korea.
authors.forename: Jeong-Sik
authors.initials: JS
authors.lastname: Yu
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Korea.
authors.forename: Jae-Joon
authors.initials: JJ
authors.lastname: Chung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology; D003287:Contrast Media / Q000627:therapeutic use*; D005260:Female; D019786:Gadolinium DTPA / Q000627:therapeutic use*; D022781:Hepatocytes / Q000473:pathology*; D006801:Humans; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000556:secondary*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA