title: Visualization of bile movement using MRI spin-labeling technique: preliminary results.
abstract: OBJECTIVE
  The purpose of this article is to noninvasively visualize intrabiliary bile movement using an MRI spin-labeling technique and administration of water, full-fat milk, and negative contrast agent as stimuli for bile excretion.
  
  
  METHODS
  Six healthy volunteers underwent three studies with each of three oral liquid agents (water, full-fat milk, and manganese chloride solution) for a total of 18 MRI studies. Oblique-coronal T2-weighted images of the common bile duct were acquired at an inversion time of 1500 milliseconds after pulse labeling using a spin-labeling technique with an inversion pulse, repeated at intervals of 22 seconds. Bile flow rate was measured before and for 50 minutes after administration of the oral liquid agents, and its correlation with the change in gallbladder volume was assessed.
  
  
  RESULTS
  Both anterograde and retrograde intermittent bile movements were successfully visualized in the common bile duct. The summation of excreted bile volume calculated from spin-labeled images correlated significantly with a decrease in gallbladder volume (p = 0.011). Milk stimulated significantly prolonged bile flow; flow was momentary with manganese chloride and mild with water; however, gallbladder volume decreased only in milk studies (p = 0.003). Biliary flow early after oral intake correlated significantly with gallbladder contractility at 50 minutes after oral intake (p = 0.049).
  
  
  CONCLUSIONS
  A new method for visualizing intrabiliary bile movement in semi-real time (22-second time resolution) using an MRI spin-labeling technique was proposed. Bile was shown to be excreted in a to-and-fro type of movement. Administration of water and negative contrast agent may induce temporary bile excretion.
authors.affiliation: Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan. watapi-tky@umin.net
authors.forename: Wataru
authors.initials: W
authors.lastname: Gonoi
authors.forename: Masaaki
authors.initials: M
authors.lastname: Akahane
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Sachiko
authors.initials: S
authors.lastname: Isono
authors.forename: Eriko
authors.initials: E
authors.lastname: Maeda
authors.forename: Kazuchika
authors.initials: K
authors.lastname: Hagiwara
authors.forename: Kuni
authors.initials: K
authors.lastname: Ohtomo
mesh_terms: D000328:Adult; D000818:Animals; D001646:Bile / Q000378:metabolism*; D001652:Bile Ducts / Q000033:anatomy & histology*; D002417:Cattle; D002712:Chlorides / Q000008:administration & dosage; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D017895:Manganese Compounds / Q000008:administration & dosage; D008892:Milk; D013113:Spin Labels; D018709:Statistics, Nonparametric; D014867:Water / Q000008:administration & dosage
chemical_list: D002712:Chlorides; D003287:Contrast Media; D017895:Manganese Compounds; D013113:Spin Labels; D014867:Water; C025340:manganese chloride