CT is capable of detecting choledochal stones and other investigations include X-ray radiographs, ultrasound, endoscopic ultrasound, PTC, ERCP and MRCP.
One of the many tests for choledochal stones is CT, which is able to detect dilatation of the choledochal ducts and the location of stones, and is not affected by dilatation of the intestinal gas.
X-rays can detect calcium-containing stones; ultrasound is the preferred test to detect stones and define their size and location; and ultrasound endoscopy is important for the diagnosis of distal choledochal stones.
PTC (percutaneous transhepatic cholangiography) and ERCP (retrograde cholangiopancreatography) are invasive tests, but they can remove and show stones; MRCP (magnetic resonance cholangiopancreatography) is a non-invasive test, which can help to find out the site of obstruction.
If you feel unwell, it is recommended that you seek medical attention as soon as possible.