title: Respiratory motion compensated MR cholangiopancreatography at 3.0 Tesla.
abstract: OBJECTIVE
  To reduce irregular respiratory motion-induced artifacts in free-breathing prospective navigator-triggered three-dimensional (3D) MR cholangiopancreatography (MRCP).
  
  
  METHODS
  A reference respiration model was estimated from the first-five respiration periods during the initial navigator scan. With the navigator information acquired before and after triggering, the un-acquired diaphragm position during the actual imaging was interpolated using the amplitude-scaled reference model. Craniocaudal translational motion during imaging was retrospectively corrected using the estimated diaphragm position. T2-weighted 3D MRCP data were acquired from 17 healthy volunteers. For quantitative analysis, contrast-to-noise ratio (CNR) and relative contrast (RC) of the biliary tree and gallbladder were compared using the paired t-test.
  
  
  RESULTS
  The CNR and RC of the biliary tree and gallbladder were significantly higher (P < 0.05) in the maximum intensity projection images after motion compensation.
  
  
  CONCLUSIONS
  The proposed algorithm can be an effective tool to reduce the irregular respiratory motion-induced artifacts in 3D MRCP imaging.
authors.affiliation: Department of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea.
authors.forename: Sang-Young
authors.initials: SY
authors.lastname: Zho
authors.forename: Jaeseok
authors.initials: J
authors.lastname: Park
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Kim
mesh_terms: D016477:Artifacts; D049448:Cholangiopancreatography, Magnetic Resonance / Q000379:methods*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D009038:Motion; D012016:Reference Values; D012119:Respiration; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity