What is the expected maximum thickness for the gallbladder wall?
About 3 mm is considered the upper limit for gallbladder wall thickness. It is important to take time to get the best images for this, as if caught obliquely your measurement will be thicker than it actually is.
What is the most sensitive sign for acute cholecystitis on ultrasound?
Although presence of stones, wall thickness, biliary dilatation and pericholecystic fluid are essential for assessment, usually the most sensitive sign is if the patient is tender on placing the probe in the right upper quadrant (Murphy's sign).
What is the next radiological step with this case?
To determine the impact of the calculi, and to see if there are ductal stones or other obstructions, MRCP (magnetic resonance cholangiopancreatography) is usually performed. If an intervention is expected, the clinical team may pursue an ERCP.
Thickwalled gallbladder (measuring 6 mm) with large calculus obstructing the neck. Sludge in the gallbladder but no other calculi, nor in the ducts. Trace pericholecystic fluid.
Dilated common bile duct (about 8 mm) with intrahepatic biliary dilatation. Patent portal vein.