Radiology, Vol 160, 29-31, Copyright © 1986 by Radiological Society of North America
Unchanged size of a dilated common bile duct after a fatty meal: results and significance
SA Willson, BB Gosink and E vanSonnenberg
Sonographic measurement of common bile duct caliber alone is insufficient
to ascertain the presence of obstruction. Fatty meal stimulation
significantly improves diagnostic accuracy. An increase in caliber of a
normal or slightly dilated common duct after the subject has ingested a
fatty meal is a strong indicator of biliary obstruction, while a decrease
in caliber indicates normal dynamics and virtually excludes obstruction.
This study determines the significance of no change in the caliber of the
dilated common bile duct of subjects who have eaten a fatty meal. Further
imaging studies and clinical/laboratory follow-up of 31 patients showed
that in 84% of the cases no obstruction was present. A dilated common duct
that does not decrease in size after a fatty meal is not a specific
indicator of obstruction. The use of invasive diagnostic procedures in
these patients is not advised unless there is other evidence of biliary
obstruction.
