Diagnostic ultrasound ( PDFDrive )

CHAPTER 6 The Biliary Tree and Gallbladder 195
A
B
FIG. 6.36 Gallstones. (A) Sagittal image shows multiple dependent stones appearing as echogenic foci with posterior acoustic shadowing.
(B) “Wall-echo-shadow complex” in a gallbladder illed with stones. Gallbladder wall (arrow) is thin. See also Video 6.9.
A
B
FIG. 6.37 Milk of Calcium Bile. (A) Sonogram and (B) corresponding CT scan show a bile calcium level.
15% became symptomatic. 78 he complications of biliary sludge
are stone formation, biliary colic, acalculous cholecystitis, and
pancreatitis.
he sonographic appearance of sludge is that of amorphous,
low-level echoes within the gallbladder in a dependent position,
with no acoustic shadowing. With a change in patient position,
sludge may slowly resettle in the most dependent location. In
fasting, critically ill patients, sludge may be present in large
quantities and completely ill the gallbladder. Sludge that mimics
polypoid tumors is called tumefactive sludge (Fig. 6.38). Lack
of internal vascularity, potential mobility of the sludge, and a
normal gallbladder wall are all clues to the presence of sludge.
When doubts persist, lack of contrast enhancement on ultrasound,
CT, or MRI allows conservative management. Occasionally, sludge
has the same echotexture as the liver, camoulaging the gallbladder;
called hepatization of the gallbladder, this may be easily recognized
by identifying the normal gallbladder wall, and lack of
Doppler low within the sludge.
Acute Cholecystitis
Acute cholecystitis is a relatively common disease, accounting
for 5% of the patients arriving to the emergency department
with abdominal pain and 3% to 9% of hospital admissions. 79 It
is caused by gallstones in more than 90% of patients. 80 Impaction
of the stones in the cystic duct or the gallbladder neck results
in obstruction, with luminal distention, ischemia, superinfection,