title: Diffusion-weighted echo-planar imaging of the head and neck using 3-T MRI: Investigation into the usefulness of liquid perfluorocarbon pads and choice of optimal fat suppression method.
abstract: OBJECTIVE
  To investigate whether image quality can be improved using liquid perfluorocarbon pads (Sat Pad) and clarify the optimal fat-suppression method among chemical shift selective (CHESS), water excitation (WEX), and short TI inversion recovery (STIR) methods in diffusion-weighted imaging (DWI) of the head and neck using 3-T magnetic resonance imaging. Correlations between results of visual inspection and quantitative analysis were also examined.
  
  
  METHODS
  This study was approved by our Institutional Review Board and informed consent was waived. DWI was performed on 25 subjects with/without Sat Pad and using three fat-suppression methods (6 patterns). Image quality was evaluated visually (4-point scales and lesion-depiction capability) and by quantitative analysis (signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR)). Two-way repeated-measures analysis of variance (ANOVA) was used to detect significant differences in scores of visual evaluation, SNR, and CNR.
  
  
  RESULTS
  Mean visual evaluation scores were significantly higher with Sat Pad using STIR than without Sat Pad for all fat-suppression methods (P<0.05). DWI with Sat Pad using STIR tended to be useful for depicting lesions. DWI using STIR showed reduced W-SNR (W: whole area of depicted structure) and CNR (between semispinalis capitis muscle and subcutaneous fat) due to fewer artifacts and uniform fat suppression.
  
  
  CONCLUSIONS
  Combining Sat Pad with STIR provides good image quality for visual inspections. When numerous artifacts are present and fat suppression is insufficient, higher SNR and CNR do not always provide good diagnostic image quality.
authors.affiliation: Department of Radiology, Kansai Medical University Hirakata Hospital, Osaka 573-1010, Japan. Electronic address: minominobb@ybb.ne.jp.
authors.forename: Minoru
authors.initials: M
authors.lastname: Maehara
authors.affiliation: Department of Radiology, Kansai Medical University Takii Hospital, Osaka 570-8507, Japan.
authors.forename: Koshi
authors.initials: K
authors.lastname: Ikeda
authors.affiliation: Department of Radiology, Kansai Medical University Hirakata Hospital, Osaka 573-1010, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kurokawa
authors.affiliation: Department of Radiology, Kansai Medical University Kori Hospital, Osaka 572-8551, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Ohmura
authors.affiliation: Department of Radiology, Kansai Medical University Hirakata Hospital, Osaka 573-1010, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Ikeda
authors.affiliation: Department of Radiology, Kansai Medical University Hirakata Hospital, Osaka 573-1010, Japan.
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Hirokawa
authors.affiliation: Department of Radiology, Kansai Medical University Hirakata Hospital, Osaka 573-1010, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Maehara
authors.affiliation: Department of Radiology, Kansai Medical University Takii Hospital, Osaka 570-8507, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Utsunomiya
authors.affiliation: Department of Radiology, Kansai Medical University Hirakata Hospital, Osaka 573-1010, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Tanigawa
authors.affiliation: Department of Radiology, Kansai Medical University Hirakata Hospital, Osaka 573-1010, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sawada
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D016477:Artifacts; D038524:Diffusion Magnetic Resonance Imaging / Q000295:instrumentation*; D017352:Echo-Planar Imaging / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D005466:Fluorocarbons; D006258:Head and Neck Neoplasms / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012996:Solutions; D013382:Subtraction Technique / Q000295:instrumentation*; D055815:Young Adult
chemical_list: D005466:Fluorocarbons; D012996:Solutions
keywords: 3-T MRI; Diffusion-weighted imaging; Fat suppression; Head and neck; Liquid perfluorocarbon pads