title: Preoperative evaluation of the cystic duct for laparoscopic cholecystectomy: comparison of navigator-gated prospective acquisition correction- and conventional respiratory-triggered techniques at free-breathing 3D MR cholangiopancreatography.
abstract: OBJECTIVE
  To evaluate the quality of magnetic resonance cholangiopancreatography (MRCP) images obtained with a three-dimensional navigator-gated (NG) technique and compare findings with conventional respiratory-triggered (RT) images in pre-laparoscopic cholecystectomy patients.
  
  
  METHODS
  Turbo-spin-echo (TSE) RT-MRCP (average 242 s) and balanced turbo-field-echo (bTFE) NG-MRCP (average 263 s) were acquired at 1.5-T MRI for 49 pre-laparoscopic cholecystectomy patients. Two radiologists independently assessed image quality, visibility of anatomical structures, common bile duct (CBD) stones, and signal-to-noise ratios (SNRs). Interobserver agreement was also evaluated.
  
  
  RESULTS
  The anatomical details of the cystic duct were clearly demonstrated in 33 (67.3 %, reader A) and 35 (71.4 %, reader B) patients on RT-MRCP, and in 45 (91.8 %) and 44 (89.7 %) patients on NG-MRCP. On NG-MRCP, visualisation of the cystic duct (3.22/3.12), its origin (3.57/3.55), and the gallbladder(3.61/3.59) was statistically better than on RT-MRCP (2.90/2.78, 3.29/3.12, 2.98/2.88, respectively). The overall image quality was statistically better on NG-MRCP than RT-MRCP. Each technique identified the presence of CBD stones in all affected patients. The SNR was significantly higher on NG-MRCP (CHD 22.40, gallbladder 17.13) than RT-MRCP (CHD 17.05, gallbladder 9.30). Interobserver agreement was fair to perfect.
  
  
  CONCLUSIONS
  Navigator-gated MRCP is more useful than respiratory-triggered MRCP for evaluating the gallbladder and cystic duct in patients scheduled for laparoscopic cholecystectomy.
  
  
  CONCLUSIONS
  • Magnetic resonance cholangiopancreatography (MRCP) provides important cystic duct information before laparoscopic cholecystectomy. • Navigator-gated (NG) MRCP images were better than conventional respiratory-triggered (RT) MRCP. • The signal-to-noise ratio was significantly higher for NG-MRCP than for conventional RT-MRCP. • Balanced turbo-field-echo NG-MRCP is useful for evaluating the gallbladder and cystic duct.
authors: Department of Radiology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Kumamoto 862-0965, Japan.
authors: Ryo
authors: R
authors: Itatani
authors: Tomohiro
authors: T
authors: Namimoto
authors: Hiroo
authors: H
authors: Kajihara
authors: Akira
authors: A
authors: Yoshimura
authors: Kazuhiro
authors: K
authors: Katahira
authors: Jiro
authors: J
authors: Nasu
authors: Ikuo
authors: I
authors: Matsushita
authors: Fumi
authors: F
authors: Sakamoto
authors: Masafumi
authors: M
authors: Kidoh
authors: Yasuyuki
authors: Y
authors: Yamashita
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D049448:Cholangiopancreatography, Magnetic Resonance / Q000295:instrumentation / Q000379:methods*; D002763:Cholecystectomy / Q000295:instrumentation / Q000379:methods*; D003549:Cystic Duct / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional / Q000379:methods*; D010535:Laparoscopy / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D012119:Respiration; D012189:Retrospective Studies; D059629:Signal-To-Noise Ratio