Calculi plus a thick wall is not the diagnosis — a SONOGRAPHIC Murphy sign elicited with the probe on the gallbladder is what makes it acute.
Orient first
- Gallstones are common and usually silent. What makes cholecystitis ACUTE is obstruction of the cystic duct and inflammation, and the imaging signs of inflammation are what you must find.
- The sonographic Murphy sign is not the clinical one: it is maximal tenderness elicited by the PROBE, over the visualised gallbladder, while you are watching it.
- Wall thickening is the least specific sign in the abdomen — it happens in hepatitis, heart failure, hypoalbuminaemia, ascites, and a contracted post-prandial gallbladder.
Acquire the study
- Fasted at least 6 hours where possible — a contracted gallbladder has a thick wall and is uninterpretable.
- Curvilinear probe, subcostal and intercostal; left lateral decubitus to move stones and to bring the neck into view.
- Measure the wall on the ANTERIOR wall — the posterior wall is affected by through-transmission.
- Roll the patient to test stone MOBILITY and to unmask a stone impacted at the neck.
The manoeuvre
- Find calculi: number, size, and crucially whether one is IMPACTED at the neck or in the cystic duct and does not move when the patient rolls.
- Measure the anterior wall thickness (normal up to 3 mm in a distended, fasted gallbladder).
- Look for wall striation or oedema, and for pericholecystic fluid.
- Elicit the SONOGRAPHIC Murphy sign with the probe directly over the gallbladder, and state explicitly whether it is positive, negative, or could not be assessed.
- Assess distension — a tense, rounded gallbladder supports obstruction.
- Measure the CBD (normal up to 6 mm in the non-cholecystectomised adult) and look for intrahepatic duct dilatation — the question behind this is choledocholithiasis.
- Look for complications: gas in the wall or lumen (emphysematous), a discontinuous wall or a pericholecystic collection (perforation), a sloughed membrane (gangrenous).
What confirms it
- Calculi, a thickened distended gallbladder, pericholecystic fluid AND a positive sonographic Murphy sign together.
- The conjunction matters — any one of these alone is weak evidence.
What licenses you to exclude it
- A fasted, distended, thin-walled gallbladder with no calculi and a negative sonographic Murphy sign makes acute calculous cholecystitis very unlikely.
- ⚠️ Acalculous cholecystitis exists and occurs in the critically ill, where the Murphy sign cannot be elicited. Absence of stones is not exclusion in that population.
- A non-fasted patient makes wall thickness uninterpretable — say so rather than reporting a number.
The classic misread
- Reporting wall thickness on a contracted post-prandial gallbladder.
- Calling cholecystitis on stones plus a thick wall in a patient with ascites or heart failure.
- Not stating whether the Murphy sign was assessable — it is uninterpretable in a sedated or obtunded patient.
- Missing an impacted neck stone because the patient was never rolled.