Choledocholithiasis: diagnosis by ultrasound.

The ultrasound findings of 100 patients with chloedocholithiasis documented by cholangiography and/or surgery were reviewed retrospectively. Common duct stones were detected in 45% of patients. This detection rate which is comparable with most series confirmed the lack of reliability of ultrasound in the diagnosis of choledocholithiasis. All the stones detected were in dilated common ducts. The main limiting factor was overlying bowel gas which impair visualisation of the lower part of the common duct. Despite the apparent insensitivity of ultrasound to detect common duct stones, the modality is still a valuable non-invasive screening diagnostic tool, because in positive cases, patients may be spared from invasive cholangiographic procedures.