Diagnostic Ultrasound - Abdomen and Pelvis

Cholelithiasis
Diagnoses: Biliary System
Focal Adenomyomatosis
• Focal polypoid lesion or wall thickening
• Gallbladder fundus or body; nonmobile
• Reverberation/"comet tail" artifacts due to cholesterol
deposits within Rokitansky-Aschoff sinuses
Parasite Infestation in Gallbladder
• Tubular configuration, double parallel echogenic lines
• Active movement in viable worm, gravity-dependent
movement in dead worm
Bowel Gas
• Echo with posterior reverberation
Emphysematous Cholecystitis
• Reverberation from gas in GB wall
• Wall thickening and other signs of cholecystitis
PATHOLOGY
General Features
• Etiology
○ Excessive biliary cholesterol, altered bile salts and
phospholipids, stasis and infection are predisposing
factors
– Hemolytic diseases: Sickle cell disease, thalassemia,
hereditary spherocytosis
– Cholestasis: Biliary tree malformation such as
choledochal cyst, Caroli disease, TPN, cirrhosis
– Metabolic disorders: Obesity, cystic fibrosis, diabetes,
pancreatic diseases, hyperlipidemia, pregnancy
– Intestinal malabsorption: Crohn disease, bariatric
surgery, ileal resection
• Genetics
○ Familial in some racial groups: Navajo, Pima, Chippewa
Native Americans
Gross Pathologic & Surgical Features
• 80% cholesterol stones, containing > 50% cholesterol by
definition
• 20% pigmented stones, containing cholesterol and calcium
carbonate/bilirubinate
○ Black pigmented stones occur in hemolytic disorders and
cirrhosis
○ Brown pigmented stones occur in chronic bacterial or
parasitic infection, bile ducts more common than
gallbladder
Microscopic Features
• Varied degree of acute/chronic inflammatory changes
within gallbladder wall
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Right upper quadrant pain/discomfort after fatty meal
• Other signs/symptoms
○ Asymptomatic, incidental finding on imaging
○ Complications including acute or chronic cholecystitis,
choledocholithiasis, cholangitis, pancreatitis, gallstone
ileus, or cancer of gallbladder
Demographics
• Age
○ Peak: 5th to 6th decade, increases with age
• Gender
○ M:F = 1:3
• 10-15% of population, most common in obese female in
their 5th decade
• Rare in neonates unless predisposing causes such as
obstructive congenital biliary lesion, dehydration, infection,
hemolytic anemia
• Older children associated with sickle cell disease, cystic
fibrosis, hemolytic anemia, Crohn disease
Natural History & Prognosis
• Increasing cause of hospitalization, 20% symptomatic, 1-2%
require cholecystectomy
• Excellent prognosis unless complications occur
Treatment
• Conservative management if asymptomatic
• If symptomatic, laparoscopic cholecystectomy, rarely open
surgical reaction
• Nonsurgical management with dissolution therapy or
extracorporeal shock wave lithotripsy prone to recur
DIAGNOSTIC CHECKLIST
Consider
• Ultrasound is best imaging tool for evaluation of patients
with upper abdominal pain/discomfort
• Consider cholelithiasis in patients with RUQ
pain/discomfort after fatty meal, especially in obese
middle-age female
Image Interpretation Pearls
• Important to demonstrate posterior acoustic shadowing
and mobility
• Nonshadowing calculi may be mistaken for other lesions in
GB such as polyp, sludge, carcinoma
• Contracted stone filled GB: Look for WES sign or look in
interlobar fissure
SELECTED REFERENCES
1. Knab LM et al: Cholecystitis. Surg Clin North Am. 94(2):455-70, 2014
2. O'Connell K et al: Bile metabolism and lithogenesis. Surg Clin North Am.
94(2):361-75, 2014
3. Duncan CB et al: Evidence-based current surgical practice: calculous
gallbladder disease. J Gastrointest Surg. 16(11):2011-25, 2012
4. Gore RM et al: Gallbladder imaging. Gastroenterol Clin North Am. 39(2):265-
87, ix, 2010
5. Gurusamy KS et al: Surgical treatment of gallstones. Gastroenterol Clin
North Am. 39(2):229-44, viii, 2010
6. Stinton LM et al: Epidemiology of gallstones. Gastroenterol Clin North Am.
39(2):157-69, vii, 2010
7. Venneman NG et al: Pathogenesis of gallstones. Gastroenterol Clin North
Am. 39(2):171-83, vii, 2010
8. Jüngst C et al: Gallstone disease: Microlithiasis and sludge. Best Pract Res
Clin Gastroenterol. 20(6):1053-62, 2006
9. 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
10. Leung JW et al: Hepatolithiasis and biliary parasites. Baillieres Clin
Gastroenterol. 11(4):681-706, 1997
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