- plain abdominal x-ray:
- majority of stones are not radio-opaque
- can show air in the biliary tree; gallstone ileus
- ultrasound:
- the most common diagnostic test which is rapid and non-invasive
- has a high diagnostic accuracy (90% sensitivity and 88% specificity) (2)
- shows number and size of stones
- shows dilatation of bile ducts above sites of obstruction of biliary tree; also, visualises pancreas
- stones must be larger than 1-2 mm to be seen
- number of stones may be underestimated - important if planning medical treatment
- not very good at determining gallbladder function
- oral cholecystogram:
- now has a secondary role to ultrasound scanning
- dependent on normal liver function
- shows that there is a functioning gallbladder
- can demonstrate adenomyomatosis and cholesterolosis
- nuclear scanning:
- uses technetium 99-m bound to an iminodiacetic acid e.g. HIDA
- examines gallbladder filling
- 95% sensitive in presence of good history and supporting signs
- ERCP:
- the best method for demonstrating stones in the common bile duct
- therapeutic procedures, such as stone removal or sphincterotomy of the ampulla of Vater can be carried out at the same time (3)
If there is acute bile duct obstruction it is common to see a transaminitis (ALT, AST) up to 10 times normal values (1)
- if there is chronic obstruction then alkaline phosphatase and gamma glutamyl transferase may be raised - there may also be an elevated amylase
NICE state to (4):
Consider magnetic resonance cholangiopancreatography (MRCP) if ultrasound has not detected common bile duct stones but the:
- bile duct is dilated and/or
- liver function test results are abnormal
Consider endoscopic ultrasound (EUS) if MRCP does not allow a diagnosis to be made.
Refer people for further investigations if conditions other than gallstone disease are suspected
Reference: