Stones are mixtures of cholesterol, calcium bilirubinate and calcium carbonate. Cholesterol stones make up 75% and pigmented stones the remainder (25% not visualized on CT) . Stones appear similar on US.
- Polyp - do not move or shadow
- Sludge - mobile collection of crystals, does not shadow
- Shadowing Bowel Gas - can differential with (WES)
- Wall Fold
- Emphasematous Cholecystitis - from gas forming bacteria, echo in non-dependant portion of GB and ring down effect.
- Cholesterolosis - cholesterol deposits in tissue
- Adenomyomatosis - benign tumor
Wall Echo Shadow (WES)
Differeciates shadowing bowel gas and cholelithiasis.
Gall stones have three distinct lines:
- Echogenic Line - pericholecystic fat
- Hypoechoic Line - GB wall
- Echogenic Line - stone