Journal of Ultrasound in Medicine, Vol 13, Issue 8 617-621, Copyright © 1994 by American Institute of Ultrasound in Medicine
Respiratory variation of extrahepatic bile duct diameter during ultrasonography
R. H. Wachsberg
Department of Radiology, University Hospital, Newark, NJ 07103.
The attachments and adjacent structures of the extrahepatic bile duct may
not move uniformly throughout the respiratory cycle, potentially affecting
the diameter of the common bile duct. This study was performed to evaluate
possible respiratory variation in extrahepatic bile duct diameter. Thirty
consecutive subjects with maximal anteroposterior common bile duct diameter
of 5 mm or greater were studied. Inspiratory increase in ductal diameter
exceeding 1 mm was noted in 11 subjects (37%), eight without biliary
obstruction. Awareness of this normal phenomenon may avert sonographic
misdiagnosis of common bile duct obstruction, particularly during
fatty-meal sonography.