title: Prospective trial of a navigator setting under left hepatic lobe on magnetic resonance cholangiopancreatography using a free-breathing prospective acquisition correction technique.
abstract: OBJECTIVE
  To prospectively compare the image acquisition time and image quality obtained by navigator setting under the left hepatic lobe vs. on the right diaphragm on magnetic resonance cholangiopancreatography (MRCP) using a free-breathing navigator-triggered prospective acquisition correction technique (PACE).
  
  
  METHODS
  Fifty consecutive patients prospectively underwent three-dimensional T2-weighted turbo spin-echo MRCP using PACE with the navigator randomly set either under the left hepatic lobe or on top of the right diaphragm. Image acquisition time and subjective image quality were compared on a five-point scale using Student's t-test and Mann-Whitney's U test, respectively.
  
  
  RESULTS
  There was no significant difference for mean acquisition time (6.1+/-1.6 vs. 6.3+/-1.2 min, P=.689) between the left hepatic lobe group and right diaphragm group. Mean subjective image quality was significantly worse in the left hepatic lobe group than in the right diaphragm group (4.1 vs. 4.7, P=.044).
  
  
  CONCLUSIONS
  Setting the navigator under the left hepatic lobe for MRCP using PACE causes the data processing to be more difficult. As well, under current circumstances, it does not contribute to reducing acquisition time or improving the image quality.
authors.affiliation: Department of Radiology, Tokyo Women's Medical University Medical Center East, Tokyo 116-8567, Japan. i@imodey.com
authors.forename: Satoru
authors.initials: S
authors.lastname: Morita
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: Eiko
authors.initials: E
authors.lastname: Ueno
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Chiaki
authors.initials: C
authors.lastname: Imura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D049448:Cholangiopancreatography, Magnetic Resonance / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008099:Liver / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012119:Respiration