History :
The 64 y/o male suffered from abdominal pain without nausea,vomiting and diarrhea.

Image finding :
GB wall thickening with rupture into GB bed. Severe adhesion around GB.
White bile(+) with pus in GB.

Diagnosis :
Acute cholecystitis.

Discussion :
Acute Cholecystitis
Etiology:
-(a)in 80-95% cystic duct obstruction by impacted calculus; 85% disimpact spontaneously
-(b)in 10% acalculous cholecystitis

Pathogenesis:
-chemical irritation from concentrated bile, bacterial infection, reflux of pancreatic secretions
 Age peak:
-5th-6th decade; M:F = 1:3

persisting (>6 hours) RUQ pain radiating to right shoulder / scapula / interscapular area (DDx: biliary colic usually <6 hours) nausea, vomiting, chills, fever RUQ tenderness + guarding leukocytosis, elevated levels of alkaline phosphatase and transaminase and amylase
mild hyperbilirubinemia (20%) Murphy sign = inspiratory arrest upon palpation of GB area (falsely positive in 6% of patients with cholelithiasis)

Cx:

1. Gangrene of gallbladder
   -shaggy, irregular, asymmetric wall (mucosal ulcers, intraluminal hemorrhage, necrosis)
   -hyperechoic foci within GB wall (microabscesses in Rokitansky-Aschoff sinuses)
   -intraluminal pseudomembranes (gangrene)
   -coarse nonshadowing nondependent echodensities (= sloughed necrotic mucosa / sludge / pus / clotted blood within gallbladder)
2. Perforation of gallbladder (in 2-20%)
   • acute free perforation with peritonitis causing pericholecystic abscess in 33%
   • subacute localized perforation causing pericholecystic abscess in 48%
   • chronic perforation resulting in internal biliary fistula causing pericholecystic abscess in 18%
     Location:most commonly perforation of fundus gallstone lying free in peritoneal cavity sonolucent / complex collection surrounding GB
3. Empyema of gallbladder multiple medium / coarse highly reflective intraluminal echoes without shadowing / layering / gravity dependence (purulent exudate / debris)