title: Diffusion-weighted imaging of the liver at 3 T using section-selection gradient reversal: emphasis on chemical shift artefacts and lesion conspicuity.
abstract: OBJECTIVE
  To assess the value of section-selection gradient reversal (SSGR) in liver diffusion-weighted imaging (DWI) by comparing it to conventional DWI with an emphasis on chemical shift artefacts and lesion conspicuity.
  
  
  METHODS
  Forty-eight patients (29 men and 19 women; age range 33-80 years) with 48 liver lesions underwent two DWI examinations using spectral presaturation with inversion recovery fat suppression with and without SSGR at 3 T. Two reviewers evaluated each DWI (b = 100 and b = 800 image) with respect to chemical shift artefacts and liver lesion conspicuity using five-point scales and performed pairwise comparisons between the two DWIs. The signal-to-noise ratio (SNR) of the liver and the lesion and the lesion-liver contrast-to-noise ratio (CNR) were also calculated.
  
  
  RESULTS
  SSGR-DWI was significantly better than conventional DWI with respect to chemical shift artefacts and lesion conspicuity in both separate reviews and pairwise comparisons (p < 0.05). There were significant differences in the SNR of the liver (b = 100 and b = 800 images) and lesion (b = 800) between SSGR-DWI and conventional DWI (p < 0.05).
  
  
  CONCLUSIONS
  Applying the SSGR method to DWI using SPIR fat suppression at 3 T could significantly reduce chemical shift artefacts without incurring additional acquisition time or SNR penalties, which leads to increased conspicuity of focal liver lesions.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: J S
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. Electronic address: jmyr@dreamwiz.com.
authors.forename: Y K
authors.initials: YK
authors.lastname: Kim
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: W K
authors.initials: WK
authors.lastname: Jeong
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: D
authors.initials: D
authors.lastname: Choi
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: W J
authors.initials: WJ
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008099:Liver / Q000473:pathology*; D008113:Liver Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA