Diagnostic Ultrasound - Abdomen and Pelvis

Acute Calculous Cholecystitis
Diagnoses: Biliary System
Gallbladder Carcinoma
• Wall thickening more irregular
• Soft tissue mass± extension beyond GB
• Associated with gall stones
Hyperplastic Cholecystosis
• "Comet tail" artifacts from thick wall, no tenderness
PATHOLOGY
General Features
• Etiology
○ 85-95% of acute cholecystitis due to calculous
cholecystitis (5-15% acalculous)
– Obstructing stone in cystic duct
• Genetics
○ Increased incidence of gallstones in selected population
– Hispanics, Pima Native Americans
Staging, Grading, & Classification
• Nonperforated
○ GB wall intact
• Gangrenous
○ Shaggy, irregular, asymmetric wall (mucosal ulcers,
intraluminal hemorrhage, necrosis)
○ Intraluminal pseudomembranes
• Perforated
○ GB wall defect
○ Gallstone lying free in peritoneal cavity
○ Abscess surrounding GB or in liver
Gross Pathologic & Surgical Features
• Gallstones in gallbladder neck or cystic duct
• Thickened GB wall with hyperemia of wall
• Omental adhesions
• Vascular compromise from increased GB pressure leads to
ischemia
Microscopic Features
• Lumen: Gallstones, sludge
• GB mucosa: Ulcerations
• GB wall: Acute polymorphonuclear infiltration
• Bacterial cultures positive in 40-70% of patients
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Acute RUQ pain
○ Fever, nausea, vomiting, anorexia
• Other signs/symptoms
○ Positive Murphy sign
• Clinical profile
○ Increased WBC
○ May have mild elevation in liver enzymes
Demographics
• Age
○ Typically > 25 years
• Gender
○ M:F = 1:3
• Epidemiology
○ Incidence parallels prevalence of gallstones
Natural History & Prognosis
• May progress to gangrenous cholecystitis and perforation if
ischemia develops
• Excellent prognosis in uncomplicated cases or with prompt
surgery
• Complications
○ Mirizzi syndrome: Stone in cystic duct causing common
bile duct obstruction
○ Gallstone ileus: In chronic cholecystis, gallstone erodes
into bowel and causes small bowel obstruction
○ Bouveret syndrome: Gallstone erodes into duodenum
leading to duodenal obstruction
Treatment
• Prompt cholecystectomy
○ Laparoscopic surgery for uncomplicated cases
• Percutaneous cholecystostomy
○ Useful for poor operative risk patients with GB empyema
• Percutaneous drainage
○ For localized pericholecystic or intrahepatic abscesses
DIAGNOSTIC CHECKLIST
Consider
• Possibility of adjacent inflammatory disease such as
perforated ulcer, acute hepatitis, or acute pancreatitis
mimicking acute cholecystitis
Image Interpretation Pearls
• Stone impacted in cystic duct
• Diffuse GB wall thickening, distension, and pericholecystic
fluid
• Combination of gallstones, wall thickening, and positive
Murphy sign increase specificity
• Sonographic Murphy sign must be unequivocal to be
considered positive
SELECTED REFERENCES
1. Knab LM et al: Cholecystitis. Surg Clin North Am. 94(2):455-70, 2014
2. Duncan CB et al: Evidence-based current surgical practice: calculous
gallbladder disease. J Gastrointest Surg. 16(11):2011-25, 2012
3. Kiewiet JJ et al: A systematic review and meta-analysis of diagnostic
performance of imaging in acute cholecystitis. Radiology. 264(3):708-20,
2012
4. Charalel RA et al: Complicated cholecystitis: the complementary roles of
sonography and computed tomography. Ultrasound Q. 27(3):161-70, 2011
5. Gore RM et al: Gallbladder imaging. Gastroenterol Clin North Am. 39(2):265-
87, ix, 2010
6. Smith EA et al: Cross-sectional imaging of acute and chronic gallbladder
inflammatory disease. AJR Am J Roentgenol. 192(1):188-96, 2009
7. Catalano OA et al: MR imaging of the gallbladder: a pictorial essay.
Radiographics. 28(1):135-55; quiz 324, 2008
8. Hanbidge AE et al: From the RSNA refresher courses: imaging evaluation for
acute pain in the right upper quadrant. Radiographics. 24(4):1117-35, 2004
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