9%20ECOGRAFIA%20ABDOMINAL%20COMO%20CUANDO%20DONDE

PATHOLOGY OF THE GALLBLADDER AND BILIARY TREE 61
A
B
C
D
Figure 3.31 Gallbladder empyema. (A) and (B) LS and TS of the same gallbladder. The gallbladder has ruptured,
forming a cholecystoenteric fistula which had resealed at surgery. The gallbladder contains pus and stones, with several
anterior septations, forming pockets of infected bile which also contained stones (arrows). (C) CT scan confirming the
ultrasound appearances. (D) Gallbladder empyema demonstrating a large gallbladder full of pus and stones.
ultrasound represents a dilated duct or a blood vessel.
Colour Doppler will differentiate the dilated
bile duct from a branch of hepatic artery or portal
vein (Fig. 3.33).
Assessment of the cause of obstruction
The numerous causes of biliary dilatation are summarized
in Table 3.4. Frequently, ultrasound diagnoses
obstruction but does not identify the cause.
This is a good case for perseverance by the operator,
as the lower end of the CBD is visible in
the majority of cases once overlying duodenum
has been moved away (Figs 3.9, 3.10 and 33.4).
However, ultrasound is not generally regarded as a
reliable tool for identifying ductal stones and is
frequently unable to diagnose ductal strictures,
especially those from benign causes.