title: Navigator-triggered prospective acquisition correction (PACE) technique vs. conventional respiratory-triggered technique for free-breathing 3D MRCP: an initial prospective comparative study using healthy volunteers.
abstract: OBJECTIVE
  To confirm the superiority of the navigator-triggered prospective acquisition correction (PACE) technique over the conventional respiratory-triggered (RESP) technique, something that has been perceived experimentally but without definite evidence, for free-breathing three-dimensional (3D) magnetic resonance cholangiopancreatography (MRCP) using healthy volunteers.
  
  
  METHODS
  Free-breathing 3D turbo spin-echo MRCP using both PACE and RESP techniques were prospectively performed on 25 healthy volunteers. Quantitative analyses of acquisition time, signal-to-noise ratio, contrast-to-noise ratio, and contour sharpness index of each segment of the pancreaticobiliary tree were compared using the paired t-test. Qualitative analyses on a five-point scale (1, excellent; 5, poor) scored by two independent radiologists were compared using the Wilcoxon signed-rank test.
  
  
  RESULTS
  The subjective image quality and contour sharpness index of each segment of the PACE technique were found to be significantly better than those for RESP (P<0.05). No significant difference was observed with regard to signal-to-noise and contrast-to-noise ratios except for the pancreatic duct. No significant difference in acquisition times between PACE and RESP techniques was observed.
  
  
  CONCLUSIONS
  We confirmed the superiority of the image quality of the PACE technique compared to conventional RESP technique for free-breathing 3D MRCP in healthy volunteers.
authors.affiliation: Department of Radiology, Tokyo Women's Medical University Medical Center East, Tokyo, Japan. i@imodey.com
authors.forename: Satoru
authors.initials: S
authors.lastname: Morita
authors.forename: Eiko
authors.initials: E
authors.lastname: Ueno
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Suzuki
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Machida
authors.forename: Mikihiko
authors.initials: M
authors.lastname: Fujimura
authors.forename: Shinya
authors.initials: S
authors.lastname: Kojima
authors.forename: Masami
authors.initials: M
authors.lastname: Hirata
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Chiaki
authors.initials: C
authors.lastname: Imura
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D016477:Artifacts; D049448:Cholangiopancreatography, Magnetic Resonance / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D055815:Young Adult