title: Three-dimensional drip infusion CT cholangiography in patients with suspected obstructive biliary disease: a retrospective analysis of feasibility and adverse reaction to contrast material.
abstract: BACKGROUND
  Computed Tomography Cholangiography (CTC) is a fast and widely available alternative technique to visualise hepatobiliary disease in patients with an inconclusive ultrasound when MRI cannot be performed. The method has previously been relatively unknown and sparsely used, due to concerns about adverse reactions and about image quality in patients with impaired hepatic function and thus reduced contrast excretion. In this retrospective study, the feasibility and the frequency of adverse reactions of CTC when using a drip infusion scheme based on bilirubin levels were evaluated.
  
  
  METHODS
  The medical records of patients who had undergone upper abdominal spiral CT with subsequent three-dimensional rendering of the biliary tract by means of CTC during seven years were retrospectively reviewed regarding serum bilirubin concentration, adverse reaction and presence of visible contrast media in the bile ducts at CT examination. In total, 153 consecutive examinations in 142 patients were reviewed.
  
  
  RESULTS
  Contrast media was observed in the bile ducts at 144 examinations. In 110 examinations, the infusion time had been recorded in the medical records. Among these, 42 examinations had an elevated bilirubin value (>19 micromol/L). There were nine patients without contrast excretion; 3 of which had a normal bilirubin value and 6 had an elevated value (25-133 micromol/L). Two of the 153 examinations were inconclusive. One subject (0.7%) experienced a minor adverse reaction - a pricking sensation in the face. No other adverse effects were noted.
  
  
  CONCLUSIONS
  We conclude that drip infusion CTC with an infusion rate of the biliary contrast agent iotroxate governed by the serum bilirubin value is a feasible and safe alternative to MRC in patients with and without impaired biliary excretion. In this retrospective study the feasibility and the frequency of adverse reactions when using a drip infusion scheme based on bilirubin levels has been evaluated.
authors.affiliation: Center for Medical Image Science and Visualization (CMIV), Linköping University Hospital, Sweden. anders.persson@cmiv.liu.se
authors.forename: A
authors.initials: A
authors.lastname: Persson
authors.forename: N
authors.initials: N
authors.lastname: Dahlström
authors.forename: O
authors.initials: O
authors.lastname: Smedby
authors.forename: T B
authors.initials: TB
authors.lastname: Brismar