[The size of the bile duct by echograph. A study]

The purpose of this work was to determine the size of the bile duct by echograph. The frequent injuries of the bile duct in various pathologies in particular infection, made of it a very investigated organ especially by echograph. Its size can be modified by various pathologies. So it is of interest to know about its normal size.

Sixty normal subjects, among which 29 women, were examined by echograph in the university hospital of the Point G. They were voluntary subjects with an empty stomach for 12 hours. Three different sonographers successively performed this examination according to the same protocol with an Aloka SSD 1700 device type and a Kontron Medical/Imagic Maestro. These devices were provided with a convex probe of 3.5-megahertz multifrequency and with a linear probe of 7.5-megahertz. The subjects were in dorsal position. Reference points for the display of the bile duct were the liver, the gallbladder and the pancreas. The limits of the bile duct were marked by the cursor of the echograph. The transverse diameter (in mm) of the bile duct was measured in its origin and in its ending. No subject of the sample was obese enough to hamper the visibility of the gall-bladder and the bile duct and no subject had histories of cholecystectomy. Data analysis was made using the software Ear information version 6. The difference between variables was considered as significant when P<0,05.

Forty subjects out of 60 were between 20 and 39 years old. The transverse diameter of the bile duct was measured 38 times (63.3%) in its origin and 50 times (83.3%) in its ending. The failure of visibility of the proximal segment was 37.7% and the failure of visibility of the distal segment of the bile duct was 17.7%. The average transverse diameter of the bile duct in its origin was 2.61.4 mm; extremes were 2 and 5 mm. The average transverse diameter of the bile duct in its ending was 3.10.7 mm; extremes were 2 and 5 mm. The transverse diameter of the bile duct in its origin of the subjects was contained between 3 and 4 mm in 80% of the cases. The transverse diameter of the bile duct in its ending of the subjects was contained between 3 and 4 mm in 40% of the cases. The difference was very significant between the diameter of the bile duct in its origin and in its ending (P<10(-6)).

The distal segment of the bile duct was seen more accurately than the proximal segment by echograph. The diameter of the bile duct in its ending was significantly superior to that of the bile duct in its origin.