Indications:
Abdominal pain
Jaundice
Cholelithiasis
Cholecystitis
Elevated liver enzymes
Splenomegaly
Ascites
Abdominal mass
Pancreatitis
Portal vein thrombosis
Strengths:
Fast
Can be performed at bedside
No ionizing radiation
Widely available
Can provide Doppler and color flow information
Lower cost than CT
Weaknesses:
Obscuring intestinal gas
Only able to visualize 50% of bile duct stones
Inferior anatomic detail compared with CT
Affected by body habitus
Cannot be used to definitely rule out abscess
Comments:
This is often the initial diagnostic procedure of choice in patients presenting with abdominal pain or mass in RUQ and mid-abdomen. CT of abdomen is preferred in LLQ and RLQ pain or mass and in significantly obese patients.
The presence of a sonographic Murphy sign (the ultrasonographer elicits focal gallbladder tenderness under the ultrasound transducer) has a positive predictive value greater than 90% for acute cholecystitis if gallstones are present.
Ultrasound should be considered as an initial test in all patients with pancreatitis, especially if gallstones are suspected.