title: On the appearance of bile in clinical MR cholangiopancreatography.
abstract: OBJECTIVE
  To study the appearance of bile in clinical MR cholangiopancreatography (MRCP) with special reference to its chemical and physical properties.
  
  
  METHODS
  Gallbladder bile was collected during surgery from 38 patients and studied with respect to chemical constituents. The relaxation rates 1/T1 and 1/T2 of bile were also determined in vitro. In 16 of these 38 patients, abdominal imaging was performed using MRCP as well as T1-weighted GE sequences.
  
  
  RESULTS
  For 9 of the 13 chemical parameters studied, a positive significant correlation with 1/T1 as well as 1/T2 was found. The median relaxation rates 1/T1 and 1/T2 were 0.76 and 1.48 s-1, respectively. The corresponding ranges were 0.38-3.13 s-1 and 0.70-5.75 s-1, respectively. On the MRCP images a few patients showed gallbladder of poor visibility due to low signal-to-noise ratio. This coincided with a high relaxation rate 1/T2 of bile. On the T1-weighted GE sequences a few patients showed hyperintense gallbladder relative to liver, coinciding with high relaxation rates 1/T1 of bile.
  
  
  CONCLUSIONS
  Bile was found to show a large interindividual variation with respect to relaxation rates 1/T1 and 1/T2. The relaxation rates increased with increasing amounts of substances in the bile. For some patients (11%) MRCP imaging is unsuccessful due to high relaxation rate of bile.
authors.affiliation: Department of Radiology, Kalmar Hospital, Kalmar, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Håkansson
authors.forename: J O
authors.initials: JO
authors.lastname: Christoffersson
authors.forename: P
authors.initials: P
authors.lastname: Leander
authors.forename: O
authors.initials: O
authors.lastname: Ekberg
authors.forename: H-O
authors.initials: HO
authors.lastname: Håkansson
mesh_terms: D001646:Bile / Q000737:chemistry; D005704:Gallbladder / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D012189:Retrospective Studies