Investigations for Bile Duct Calculi

Bile duct stones are common, occurring in approximately 15% of patients with gallstones. Radiological techniques for preoperative detection of stones are determined by the clinical presentation of the stones. In patients who are not symptomatic, detection of a dilated bile duct on ultrasound strongly suggests bile duct stones. In up to 80% of patients, ultrasound may detect stones, but the accuracy of this technique is operator-dependent. Although there has been a resurgence of interest in intravenous cholangiography in recent years, its use is not supported on grounds of either accuracy or safety. Other techniques, such as percutaneous cholangiogram, computed tomography, and magnetic resonance imaging, may be used in those particular circumstances when endoscopic retrograde cholangiography cannot be used.